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Sample records for cardiac sympathetic activity

  1. Enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with heart failure induced by adriamycin

    OpenAIRE

    Zhang, Shujuan; Feng ZHANG; Sun, Haijian; Zhou, Yebo; Han, Ying

    2012-01-01

    Our previous studies have shown that the cardiac sympathetic afferent reflex is enhanced in rats with chronic heart failure (CHF) induced by coronary artery ligation and contributes to the over-excitation of sympathetic activity. We sought to determine whether sympathetic activity and cardiac sympathetic afferent reflex were enhanced in adriamycin-induced CHF and whether angiotensin II (Ang II) in the paraventricular nucleus (PVN) was involved in enhancing sympathetic activity and cardiac sym...

  2. Enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with heart failure induced by adriamycin.

    Science.gov (United States)

    Zhang, Shujuan; Zhang, Feng; Sun, Haijian; Zhou, Yebo; Han, Ying

    2012-11-01

    Our previous studies have shown that the cardiac sympathetic afferent reflex is enhanced in rats with chronic heart failure (CHF) induced by coronary artery ligation and contributes to the over-excitation of sympathetic activity. We sought to determine whether sympathetic activity and cardiac sympathetic afferent reflex were enhanced in adriamycin-induced CHF and whether angiotensin II (Ang II) in the paraventricular nucleus (PVN) was involved in enhancing sympathetic activity and cardiac sympathetic afferent reflex. Heart failure was induced by intraperitoneal injection of adriamycin for six times during 2 weeks (15 mg/kg). Six weeks after the first injection, the rats underwent anesthesia with urethane and α-chloralose. After vagotomy and baroreceptor denervation, cardiac sympathetic afferent reflex was evaluated by renal sympathetic nerve activity and mean arterial pressure (MAP) response to epicardial application of capsaicin (1.0 nmol). The response of MAP to ganglionic blockade with hexamethonium in conscious rats was performed to evaluate sympathetic activity. The renal sympathetic nerve activity and cardiac sympathetic afferent reflex were enhanced in adriamycin rats and the maximum depressor response of MAP induced by hexamethonium was significantly greater in adriamycin rats than that in control rats. Bilateral PVN microinjection of angiotensin II (Ang II) caused larger responses of the cardiac sympathetic afferent reflex, baseline renal sympathetic nerve activity and MAP in adriamycin rats than control rats. These results indicated that both sympathetic activity and cardiac sympathetic afferent reflex were enhanced and Ang II in the PVN was involved in the enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with adriamycin-induced heart failure. PMID:23554781

  3. Inhibition of cardiac sympathetic afferent reflex and sympathetic activity by baroreceptor and vagal afferent inputs in chronic heart failure.

    Directory of Open Access Journals (Sweden)

    Xian-Bing Gan

    Full Text Available BACKGROUND: Cardiac sympathetic afferent reflex (CSAR contributes to sympathetic activation and angiotensin II (Ang II in paraventricular nucleus (PVN augments the CSAR in vagotomized (VT and baroreceptor denervated (BD rats with chronic heart failure (CHF. This study was designed to determine whether it is true in intact (INT rats with CHF and to determine the effects of cardiac and baroreceptor afferents on the CSAR and sympathetic activity in CHF. METHODOLOGY/PRINCIPAL FINDINGS: Sham-operated (Sham or coronary ligation-induced CHF rats were respectively subjected to BD+VT, VT, cardiac sympathetic denervation (CSD or INT. Under anesthesia, renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were recorded, and the CSAR was evaluated by the RSNA and MAP responses to epicardial application of capsaicin. Either CSAR or the responses of RSNA, MAP and CSAR to Ang II in PVN were enhanced in CHF rats treated with BD+VT, VT or INT. Treatment with VT or BD+VT potentiated the CSAR and the CSAR responses to Ang II in both Sham and CHF rats. Treatment with CSD reversed the capsaicin-induced RSNA and MAP changes and the CSAR responses to Ang II in both Sham and CHF rats, and reduced the RSNA and MAP responses to Ang II only in CHF rats. CONCLUSIONS: The CSAR and the CSAR responses to Ang II in PVN are enhanced in intact CHF rats. Baroreceptor and vagal afferent activities inhibit CSAR and the CSAR responses to Ang II in intact Sham and CHF rats.

  4. Angiotensin-(1-7 in paraventricular nucleus modulates sympathetic activity and cardiac sympathetic afferent reflex in renovascular hypertensive rats.

    Directory of Open Access Journals (Sweden)

    Ying Han

    Full Text Available BACKGROUND: Excessive sympathetic activity contributes to the pathogenesis and progression of hypertension. Enhanced cardiac sympathetic afferent reflex (CSAR is involved in sympathetic activation. This study was designed to determine the roles of angiotensin (Ang-(1-7 in paraventricular nucleus (PVN in modulating sympathetic activity and CSAR and its signal pathway in renovascular hypertension. METHODOLOGY/PRINCIPAL FINDINGS: Renovascular hypertension was induced with two-kidney, one-clip method. Renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were recorded in sinoaortic-denervated and cervical-vagotomized rats with anesthesia. CSAR was evaluated with the RSNA and MAP responses to epicardial application of capsaicin. PVN microinjection of Ang-(1-7 and cAMP analogue db-cAMP caused greater increases in RSNA and MAP, and enhancement in CSAR in hypertensive rats than in sham-operated rats, while Mas receptor antagonist A-779 produced opposite effects. There was no significant difference in the angiotensin-converting enzyme 2 (ACE2 activity and Ang-(1-7 level in the PVN between sham-operated rats and hypertensive rats, but the Mas receptor protein expression in the PVN was increased in hypertensive rats. The effects of Ang-(1-7 were abolished by A-779, adenylyl cyclase inhibitor SQ22536 or protein kinase A (PKA inhibitor Rp-cAMP. SQ22536 or Rp-cAMP reduced RSNA and MAP in hypertensive rats, and attenuated the CSAR in both sham-operated and hypertensive rats. CONCLUSIONS: Ang-(1-7 in the PVN increases RSNA and MAP and enhances the CSAR, which is mediated by Mas receptors. Endogenous Ang-(1-7 and Mas receptors contribute to the enhanced sympathetic outflow and CSAR in renovascular hypertension. A cAMP-PKA pathway is involved in the effects of Ang-(1-7 in the PVN.

  5. Tonic arterial chemoreceptor activity contributes to cardiac sympathetic activation in mild ovine heart failure.

    Science.gov (United States)

    Xing, Daniel T; May, Clive N; Booth, Lindsea C; Ramchandra, Rohit

    2014-08-01

    Heart failure (HF) is associated with a large increase in cardiac sympathetic nerve activity (CSNA), which has detrimental effects on the heart and promotes arrhythmias and sudden death. There is increasing evidence that arterial chemoreceptor activation plays an important role in stimulating renal sympathetic nerve activity (RSNA) and muscle sympathetic nerve activity in HF. Given that sympathetic nerve activity to individual organs is differentially controlled, we investigated whether tonic arterial chemoreceptor activation contributes to the increased CSNA in HF. We recorded CSNA and RSNA in conscious normal sheep and in sheep with mild HF induced by rapid ventricular pacing (ejection fraction chemoreceptor function was evaluated by supplementing room air with 100% intranasal oxygen (2-3 l min(-1)) for 20 min, thereby deactivating chemoreceptors. The effects of hyperoxia on resting levels and baroreflex control of heart rate, CSNA and RSNA were determined. In HF, chemoreceptor deactivation induced by hyperoxia significantly reduced CSNA [90 ± 2 versus 75 ± 5 bursts (100 heart beats)(-1), P chemoreceptor deactivation reduced heart rate without a significant effect on CSNA or RSNA. In summary, deactivation of peripheral chemoreceptors during HF reduced the elevated levels of CSNA, indicating that tonic arterial chemoreceptor activation plays a critical role in stimulating the elevated CSNA in HF.

  6. Differential effects of defibrillation on systemic and cardiac sympathetic activity

    OpenAIRE

    Bode, F; U. Wiegand; Raasch, W; Richardt, G.; Potratz, J

    1998-01-01

    Objective—To assess the effect of defibrillation shocks on cardiac and circulating catecholamines.
Design—Prospective examination of myocardial catecholamine balance during dc shock by simultaneous determination of arterial and coronary sinus plasma concentrations. Internal countershocks (10-34 J) were applied in 30 patients after initiation of ventricular fibrillation for a routine implantable cardioverter defibrillator test. Another 10 patients were externally cardioverted (50-360 J) for at...

  7. Increased cardiac sympathetic activity in patients with hypothyroidism as determined by iodine-123 metaiodobenzylguanidine scintigraphy

    International Nuclear Information System (INIS)

    Clinical manifestations of hypothyroidism, such as bradycardia, suggest decreased sympathetic tone. However, previous studies in patients with hypothyroidism have suggested that increased plasma noradrenaline (NA) levels represent enhanced general sympathetic activity. As yet, cardiac sympathetic activity (CSA) in hypothyroidism has not been clarified. To evaluate CSA in patients with hypothyroidism, iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy was performed in eight patients with hypothyroidism before therapy and in ten normal control patients. Planar images were obtained at 15 min and 4 h after injection of MIBG. The ratio of early myocardial uptake to the total injected dose (MU) and myocardial clearance of MIBG within 4 h p.i. (MC) were calculated. Plasma NA was also measured, and echocardiography was performed in all patients. Those patients with hypothyroidism in the euthyroid state after medical therapy were also evaluated in a similar manner. Left ventricular ejection fraction, measured by echocardiography, did not differ significantly between the groups. NA, MU and MC were significantly higher in patients with hypothyroidism than in controls, and all parameters were decreased after therapy. MC was well correlated with NA in hypothyroidism (r=0.86) before therapy. We conclude that CSA is increased in patients with hypothyroidism, in parallel with the enhanced general sympathetic activity. (orig.). With 4 figs., 2 tabs

  8. Effects of short-term carvedilol on the cardiac sympathetic activity assessed by {sup 123}I-MIBG scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Sandra Marina Ribeiro de; Mesquita, Evandro Tinoco; Freire, Fabiano de Lima; Ribeiro, Mario Luiz; Nobrega, Antonio Claudio Lucas da; Mesquita, Claudio Tinoco, E-mail: sandramarina@cardiol.b [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Azevedo, Jader Cunha; Barbirato, Gustavo Borges; Coimbra, Alexandro [Hospital Pro-Cardiaco, Rio de Janeiro, RJ (Brazil); Dohmann, Hans Fernando da Rocha [Centro de Ensino e Pesquisa do Pro-Cardiaco (PROCEP), Rio de Janeiro, RJ (Brazil)

    2010-03-15

    Background: autonomic alterations in heart failure are associated with an increase in morbimortality. Several noninvasive methods have been employed to evaluate the sympathetic function, including the Meta-Iodobenzylguanidine ({sup 123}I-MIBG) scintigraphy imaging of the heart. Objective: to evaluate the cardiac sympathetic activity through {sup 123}I-MIBG scintigraphy, before and after three months of carvedilol therapy in patients with heart failure and left ventricular ejection fraction (LVEF) < 45%. Patients and methods: sixteen patients, aged 56.3 +- 12.6 years (11 males), with a mean LVEF of 28% +- 8% and no previous use of beta-blockers were recruited for the study. Images of the heart innervation were acquired with {sup 123}I-MIBG, and the serum levels of catecholamines (epinephrine, dopamine and norepinephrine) were measured; the radioisotope ventriculography (RIV) was performed before and after a three-month therapy with carvedilol. Results: patients' functional class showed improvement: before the treatment, 50% of the patients were FC II and 50% were FC III. After 3 months, 7 patients were FC I (43.8%) and 9 were FC II (56.2%), (rho = 0.0001). The mean LVEF assessed by RIV increased from 29% to 33% (rho = 0.017). There was no significant variation in cardiac adrenergic activity assessed by {sup 123}I-MIBG (early and late resting images and washout rate). No significant variation was observed regarding the measurement of catecholamines. Conclusion: the short-term treatment with carvedilol promoted the clinical and LVEF improvement. However, this was not associated to an improvement in the cardiac adrenergic activity, assessed by {sup 123}I-MIBG scintigraphy, as well as the measurement of circulating catecholamines. (author)

  9. Assessment of central chemosensitivity and cardiac sympathetic nerve activity using I-123 MIBG imaging in central sleep apnea syndrome in patients with dilated cardiomyopathy

    International Nuclear Information System (INIS)

    Iodine-123 m-iodobenzylguanidine (MIBG) imaging has been used to study cardiac sympathetic function in various cardiac diseases. Central sleep apnea syndrome (CSAS) occurs frequently in patients with chronic heart failure (CHF) and is reported to be associated with a poor prognosis. One of the mechanisms of its poor prognosis may be related to impaired cardiac sympathetic activity. However, the relationship between chemosensitivity to carbon dioxide, which is reported to correlate with the severity of CSAS, and cardiac sympathetic activity has not been investigated. Therefore, this study was undertaken to assess cardiac sympathetic function and chemosensitivity to carbon dioxide in CHF patients. The oxygen desaturation index (ODI) was evaluated in 21 patients with dilated cardiomyopathy (male/female: 19/2, left ventricular ejection fraction (LVEF)5 times/h underwent polysomnography. Patients with an apnea hypopnea index >15/h but without evidence of obstructive apnea were defined as having CSAS. Early (15 min) and delayed (4 hr) planar MIBG images were obtained from these patients. The mean counts in the whole heart and the mediastinum were obtained. The heart-to-mediastinum count ratio of the delayed image (H/M) and the corrected myocardial washout rate (WR) were also calculated. The central chemoreflex was assessed with the rebreathing method using a hypercapnic gas mixture (7% CO2 and 93% O2). Ten of the 21 patients had CSAS. The H/M ratio was similar in patients both with and without CSAS (1.57±0.18 vs. 1.59±0.14, p=0.82). However, the WR was higher in patients with CSAS than in patients without CSAS (40±8% vs. 30±12%, p<0.05). ODI significantly correlated with central chemosensitivity to carbon dioxide. Moreover, there was a highly significant correlation between WR and central chemosensitivity (r=0.65, p<0.05). However, there was no correlation between ODI and the WR (r=0.36, p=0.11). Cardiac sympathetic nerve activity in patients with CHF and CSAS is

  10. The articulo-cardiac sympathetic reflex in spinalized, anesthetized rats.

    Science.gov (United States)

    Nakayama, Tomohiro; Suzuki, Atsuko; Ito, Ryuzo

    2006-04-01

    Somatic afferent regulation of heart rate by noxious knee joint stimulation has been proven in anesthetized cats to be a reflex response whose reflex center is in the brain and whose efferent arc is a cardiac sympathetic nerve. In the present study we examined whether articular stimulation could influence heart rate by this efferent sympathetic pathway in spinalized rats. In central nervous system (CNS)-intact rats, noxious articular movement of either the knee or elbow joint resulted in an increase in cardiac sympathetic nerve activity and heart rate. However, although in acutely spinalized rats a noxious movement of the elbow joint resulted in a significant increase in cardiac sympathetic nerve activity and heart rate, a noxious movement of the knee joint had no such effect and resulted in only a marginal increase in heart rate. Because this marginal increase was abolished by adrenalectomy suggests that it was due to the release of adrenal catecholamines. In conclusion, the spinal cord appears to be capable of mediating, by way of cardiac sympathetic nerves, the propriospinally induced reflex increase in heart rate that follows noxious stimulation of the elbow joint, but not the knee joint.

  11. EFFECT OF ELECTROACUPUNCTURE ON MYOCARDIAL ISCHEMIA INDUCED CHANGES OF CARDIAC SYMPATHETIC ACTIVITY AND INVOLVEMENT OF SPINIAL δ-OPIOID,NMDA-AND NON-NMDA RECEPTORS IN THE RABBIT

    Institute of Scientific and Technical Information of China (English)

    刘俊岭; 高永辉; 陈淑萍

    2003-01-01

    Aim: To observe the effect of electroacupuncture (EA) on acute myocardial ischemia (AMI) induced changes of cardiac sympathetic discharges and the effects of some related receptors in the spinal cord. Methods: A total of 53 rabbits anesthetized with mixture solution of 25% urethane (420 mg/kg) and 1.5% chloralose (50 mg/kg)were used in this study. AMI was induced by occlusion of the ventricular branch of the left coronary artery. Discharges of the left cardiac sympathetic nerve were recorded by using a bipolar platinum electrode. Bilateral "Ximen"(PC 40)and "Kongzhui"(LU 6) were stimulated electrically by using an EA therapeutic apparatus or an electrical stimulator.DPDPE δ-opiate receptor agonist, 20 nmol, 10 μL, n= 8), Naltrindole Hydrochloride (δ-opiate receptor antagonist, 20nmol, 10 μL, n=8), DAP5 (NMDA receptor antagonist, 5 nmol, 10 μL, n=9) and CNQX (non-NMDA receptor antagonist, 5 nmol, 10 μL, n=8) were respectively injected into the thoracic subarachnoid space of the spinal cord in different groups, followed by observing their effects on changes of sympathetic activity evoked by EA of the abovementioned acupoints. Results: ① After AMI, sympathetic discharges increased (200.56± 79.89%) in 10 cases and decreased (- 59.34 ±7.06% ) in other 9 cases in comparison with their individual basal values. After EA of "Ximen" (PC 4)and "Kongzhui" (Lu 6), AMI-induced increase and decrease changes of the sympathetic activity were suppressed significantly, but the effect of EA of LU-6 was weaker than that of EA of PC-4.②Following EA of PC-4 and LU-6, sympathetic discharges increased significantly in 2 and 4 cases, decreased apparently in 7 and 3 cases, and had no striking changes in 1 and 3 cases respectively. The mean reaction threshold of sympathetic activity after EA of PC-4 and LU-6were 2.1 ± 0.65 mA and 3.28± 1.13 mA separately.③ After pre-treatment with DPDPE, the reaction threshold of the cardiac sympathetic activity to EA of PC-4 elevated

  12. Role of endothelin-1 in mediating changes in cardiac sympathetic nerve activity in heart failure.

    Science.gov (United States)

    Abukar, Yonis; May, Clive N; Ramchandra, Rohit

    2016-01-01

    Heart failure (HF) is associated with increased sympathetic nerve activity to the heart (CSNA), which is directly linked to mortality in HF patients. Previous studies indicate that HF is associated with high levels of plasma endothelin-1 (ET-1), which correlates with the severity of the disease. We hypothesized that blockade of endothelin receptors would decrease CSNA. The effects of intravenous tezosentan (a nonselective ETA and ETB receptor antagonist) (8 mg·kg(-1)·h(-1)) on resting levels of CSNA, arterial pressure, and heart rate were determined in conscious normal sheep (n = 6) and sheep with pacing-induced HF (n = 7). HF was associated with a significant decrease in ejection fraction (from 74 ± 2% to 38 ± 1%, P < 0.001) and a significant increase in resting levels of CSNA burst incidence (from 56 ± 11 to 87 ± 2 bursts/100 heartbeats, P < 0.01). Infusion of tezosentan for 60 min significantly decreased resting mean aterial pressure (MAP) in both normal and HF sheep (-8 ± 4 mmHg and -4 ± 3 mmHg, respectively; P < 0.05). This was associated with a significant decrease in CSNA (by 25 ± 26% of control) in normal sheep, but there was no change in CSNA in HF sheep. Calculation of spontaneous baroreflex gain indicated significant impairment of the baroreflex control of HR after intravenous tezosentan infusion in normal animals but no change in HF animals. These data suggest that endogenous levels of ET-1 contribute to the baseline levels of CSNA in normal animals, but this effect is absent in HF.

  13. Assessment of cardiac sympathetic nerve integrity with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Raffel, David M. E-mail: raffel@umich.edu; Wieland, Donald M

    2001-07-01

    The autonomic nervous system plays a critical role in the regulation of cardiac function. Abnormalities of cardiac innervation have been implicated in the pathophysiology of many heart diseases, including sudden cardiac death and congestive heart failure. In an effort to provide clinicians with the ability to regionally map cardiac innervation, several radiotracers for imaging cardiac sympathetic neurons have been developed. This paper reviews the development of neuronal imaging agents and discusses their emerging role in the noninvasive assessment of cardiac sympathetic innervation.

  14. Cardiac sympathetic neuronal imaging using PET

    Energy Technology Data Exchange (ETDEWEB)

    Lautamaeki, Riikka; Tipre, Dnyanesh [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Bengel, Frank M. [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Cardiovascular Nuclear Medicine, Baltimore, MD (United States)

    2007-06-15

    Balance of the autonomic nervous system is essential for adequate cardiac performance, and alterations seem to play a key role in the development and progression of various cardiac diseases. PET imaging of the cardiac autonomic nervous system has advanced extensively in recent years, and multiple pre- and postsynaptic tracers have been introduced. The high spatial and temporal resolution of PET enables noninvasive quantification of neurophysiologic processes at the tissue level. Ligands for catecholamine receptors, along with radiolabeled catecholamines and catecholamine analogs, have been applied to determine involvement of sympathetic dysinnervation at different stages of heart diseases such as ischemia, heart failure, and arrhythmia. This review summarizes the recent findings in neurocardiological PET imaging. Experimental studies with several radioligands and clinical findings in cardiac dysautonomias are discussed. (orig.)

  15. Reduction of sympathetic activity via adrenal-targeted GRK2 gene deletion attenuates heart failure progression and improves cardiac function after myocardial infarction.

    Science.gov (United States)

    Lymperopoulos, Anastasios; Rengo, Giuseppe; Gao, Erhe; Ebert, Steven N; Dorn, Gerald W; Koch, Walter J

    2010-05-21

    Chronic heart failure (HF) is characterized by sympathetic overactivity and enhanced circulating catecholamines (CAs), which significantly increase HF morbidity and mortality. We recently reported that adrenal G protein-coupled receptor kinase 2 (GRK2) is up-regulated in chronic HF, leading to enhanced CA release via desensitization/down-regulation of the chromaffin cell alpha(2)-adrenergic receptors that normally inhibit CA secretion. We also showed that adrenal GRK2 inhibition decreases circulating CAs and improves cardiac inotropic reserve and function. Herein, we hypothesized that adrenal-targeted GRK2 gene deletion before the onset of HF might be beneficial by reducing sympathetic activation. To specifically delete GRK2 in the chromaffin cells of the adrenal gland, we crossed PNMTCre mice, expressing Cre recombinase under the chromaffin cell-specific phenylethanolamine N-methyltransferase (PNMT) gene promoter, with floxedGRK2 mice. After confirming a significant ( approximately 50%) reduction of adrenal GRK2 mRNA and protein levels, the PNMT-driven GRK2 knock-out (KO) offspring underwent myocardial infarction (MI) to induce HF. At 4 weeks post-MI, plasma levels of both norepinephrine and epinephrine were reduced in PNMT-driven GRK2 KO, compared with control mice, suggesting markedly reduced post-MI sympathetic activation. This translated in PNMT-driven GRK2 KO mice into improved cardiac function and dimensions as well as amelioration of abnormal cardiac beta-adrenergic receptor signaling at 4 weeks post-MI. Thus, adrenal-targeted GRK2 gene KO decreases circulating CAs, leading to improved cardiac function and beta-adrenergic reserve in post-MI HF. GRK2 inhibition in the adrenal gland might represent a novel sympatholytic strategy that can aid in blocking HF progression.

  16. Effects of perindopril on cardiac sympathetic nerve activity in patients with congestive heart failure: comparison with enalapril

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu; Toyama, Takuji; Suzuki, Tadashi; Kurabayashi, Masahiko [Gunma University School of Medicine, Department of Cardiovascular Medicine, Maebashi, Gunma (Japan); Kumakura, Hisao; Takayama, Yoshiaki; Ichikawa, Shuichi [Cardiovascular Hospital of Central Japan, Department of Internal Medicine, Gunma (Japan)

    2005-08-01

    The production of aldosterone in the heart is suppressed by the angiotensin-converting enzyme (ACE) inhibitor perindopril in patients with congestive heart failure (CHF). Moreover, perindopril has been reported to have more cardioprotective effects than enalapril. Forty patients with CHF [left ventricular ejection fraction (LVEF) <45%; mean 33{+-}7%] were randomly assigned to perindopril (2 mg/day; n=20) or enalapril (5 mg/day; n=20). All patients were also treated with diuretics. The delayed heart/mediastinum count (H/M) ratio, delayed total defect score (TDS) and washout rate (WR) were determined from {sup 123}I-meta-iodobenzylguanidine (MIBG) images, and plasma brain natriuretic peptide (BNP) concentrations were measured before and 6 months after treatment. The left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and LVEF were also determined by echocardiography. After treatment, in patients receiving perindopril, TDS decreased from 39{+-}10 to 34{+-}9 (P<0.01), H/M ratios increased from 1.62{+-}0.27 to 1.76{+-}0.29 (P<0.01), WR decreased from 50{+-}14% to 42{+-}14% (P<0.05) and plasma BNP concentrations decreased from 226{+-}155 to 141{+-}90 pg/ml (P<0.0005). In addition, the LVEDV decreased from 180{+-}30 to 161{+-}30 ml (P<0.05) and the LVESV decreased from 122{+-}35 to 105{+-}36 ml (P<0.05). Although the LVEF tended to increase, the change was not statistically significant (from 33{+-}8% to 36{+-}12%; P=NS). On the other hand, there were no significant changes in these parameters in patients receiving enalapril. Plasma BNP concentrations, {sup 123}I-MIBG scintigraphic and echocardiographic parameters improved after 6 months of perindopril treatment. These findings indicate that perindopril treatment can ameliorate the cardiac sympathetic nerve activity and the left ventricular performance in patients with CHF. (orig.)

  17. Differential effects of cardiac sympathetic afferent stimulation on neurons in the nucleus tractus solitarius

    OpenAIRE

    Wang, Wei-zhong; Gao, Lie; Pan, Yan-Xia; Zucker, Irving H.; Wang, Wei

    2006-01-01

    Activation of the cardiacsympathetic afferent” reflex (CSAR) has been reported to depress the arterial baroreflex and enhance the arterial chemoreflex via a central mechanism. In the present study, we used single-unit extracellular recording techniques to examine the effects of stimulation of cardiac sympathetic afferents on baro- or chemosensitive neurons in the nucleus tractus solitarius (NTS) in anesthetized rats. Of 54 barosensitive NTS neurons tested for their response to epicardial ap...

  18. elPBN neurons regulate rVLM activity through elPBN-rVLM projections during activation of cardiac sympathetic afferent nerves.

    Science.gov (United States)

    Guo, Zhi-Ling; Longhurst, John C; Tjen-A-Looi, Stephanie C; Fu, Liang-Wu

    2016-08-01

    The external lateral parabrachial nucleus (elPBN) within the pons and rostral ventrolateral medulla (rVLM) contributes to central processing of excitatory cardiovascular reflexes during stimulation of cardiac sympathetic afferent nerves (CSAN). However, the importance of elPBN cardiovascular neurons in regulation of rVLM activity during CSAN activation remains unclear. We hypothesized that CSAN stimulation excites the elPBN cardiovascular neurons and, in turn, increases rVLM activity through elPBN-rVLM projections. Compared with controls, in rats subjected to microinjection of retrograde tracer into the rVLM, the numbers of elPBN neurons double-labeled with c-Fos (an immediate early gene) and the tracer were increased after CSAN stimulation (P stimulation of CSAN increased the activity of elPBN cardiovascular neurons, which was attenuated (n = 6, P stimulation (n = 5, P stimulation activates cardiovascular neurons in the elPBN and rVLM sequentially through a monosynaptic (glutamatergic) excitatory elPBN-rVLM pathway. PMID:27225950

  19. Cardiac Sympathetic Hyperactivity after Chemotherapy: Early Sign of Cardiotoxicity?

    Energy Technology Data Exchange (ETDEWEB)

    Guimarães, Sarita Lígia Pessoa de Melo Machado [Pós-Graduação em Ciências da Saúde da Universidade Federal de Pernambuco (PGCS-UFPE), Recife, PE (Brazil); Hospital Agamenon Magalhães (HAM), Recife, PE (Brazil); Brandão, Simone Cristina Soares, E-mail: simonecordis@yahoo.com.br [Pós-Graduação em Ciências da Saúde da Universidade Federal de Pernambuco (PGCS-UFPE), Recife, PE (Brazil); Andrade, Luciana Raposo [Hospital Santa Joana, Recife, PE (Brazil); Maia, Rafael José Coelho [Pós-Graduação em Ciências da Saúde da Universidade Federal de Pernambuco (PGCS-UFPE), Recife, PE (Brazil); Hospital Agamenon Magalhães (HAM), Recife, PE (Brazil); Markman Filho, Brivaldo [Pós-Graduação em Ciências da Saúde da Universidade Federal de Pernambuco (PGCS-UFPE), Recife, PE (Brazil)

    2015-09-15

    Chemotherapy with anthracyclines and trastuzumab can cause cardiotoxicity. Alteration of cardiac adrenergic function assessed by metaiodobenzylguanidine labeled with iodine-123 ({sup 123}I-mIBG) seems to precede the drop in left ventricular ejection fraction. To evaluate and to compare the presence of cardiovascular abnormalities among patients with breast cancer undergoing chemotherapy with anthracyclines and trastuzumab, and only with anthracycline. Patients with breast cancer were analyzed clinical, laboratory, electrocardiographic and echocardiographic and cardiac sympathetic activity. In scintigraphic images, the ratio of {sup 123}I-mIBG uptake between the heart and mediastinum, and the washout rate were calculated. The variables were compared between patients who received anthracyclines and trastuzumab (Group 1) and only anthracyclines (Group 2). Twenty patients, with mean age 57 ± 14 years, were studied. The mean left ventricular ejection fraction by echocardiography was 67.8 ± 4.0%. Mean washout rate was 28.39 ± 9.23% and the ratio of {sup 123}I-mIBG uptake between the heart and mediastinum was 2.07 ± 0.28. Of the patients, 82% showed an increased in washout rate, and the ratio of {sup 123}I-mIBG uptake between the heart and mediastinum decreased in 25%. Concerning the groups, the mean washout rate of Group 1 was 32.68 ± 9.30% and of Group 2 was 24.56 ± 7.72% (p = 0,06). The ratio of {sup 123}I-mIBG uptake between the heart and mediastinum was normal in all patients in Group 2, however, the Group 1, showed 50% the ratio of {sup 123}I-mIBG uptake between the heart and mediastinum ≤ 1.8 (p = 0.02). In women with breast cancer undergoing chemotherapy, assessment of cardiac sympathetic activity with {sup 123}I-mIBG appears to be an early marker of cardiotoxicity. The combination of chemotherapy showed higher risk of cardiac adrenergic hyperactivity.

  20. Cardiac sympathetic nerve terminal function in congestive heart failure

    Institute of Scientific and Technical Information of China (English)

    Chang-seng LIANG

    2007-01-01

    Increased cardiac release of norepinephrine (NE) and depleted cardiac stores of NE are two salient features of the human failing heart. Researches from my labo-ratory have shown that these changes are accompanied by a functional defect of NE uptake in the cardiac sympathetic nerve terminals. Our studies have shown that the decrease of NE uptake is caused by reduction of NE transporter density in the sympathetic nerve endings, and this change is responsible, at least in part, for the increased myocardial interstitial NE, decreased myocardial adrenoceptor density, and increased myocyte apoptosis in experimental cardiomyopathies. We have also provided evidence in both intact animals and cultured PC12 cells that the decrease of NE transporter is induced by the actions of oxidative metabolites of exogenous NE, involving endoplasmic reticulum stress and impaired N-glycosylation of the NE transporter. This change in the cardiac sympathetic NE uptake function, as demonstrated by [123I] metaiodobenzylguanidine in human studies, may not only serve as an important prognostic variable in patients with congestive heart failure, but also be used as a surrogate for the efficacies of various therapeutic interventions for heart failure. Finally, increasing evidence suggests and further studies are needed to show that the cardiac sympathetic nerve terminal function may be a direct target for pharmacologic treatment of congestive heart failure.

  1. Cardiac sympathetic denervation in 6-OHDA-treated nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Valerie Joers

    Full Text Available Cardiac sympathetic neurodegeneration and dysautonomia affect patients with sporadic and familial Parkinson's disease (PD and are currently proposed as prodromal signs of PD. We have recently developed a nonhuman primate model of cardiac dysautonomia by iv 6-hydroxydopamine (6-OHDA. Our in vivo findings included decreased cardiac uptake of a sympathetic radioligand and circulating catecholamines; here we report the postmortem characterization of the model. Ten adult rhesus monkeys (5-17 yrs old were used in this study. Five animals received 6-OHDA (50 mg/kg i.v. and five were age-matched controls. Three months post-neurotoxin the animals were euthanized; hearts and adrenal glands were processed for immunohistochemistry. Quantification of immunoreactivity (ir of stainings was performed by an investigator blind to the treatment group using NIH ImageJ software (for cardiac bundles and adrenals, area above threshold and optical density and MBF StereoInvestigator (for cardiac fibers, area fraction fractionator probe. Sympathetic cardiac nerve bundle analysis and fiber area density showed a significant reduction in global cardiac tyrosine hydroxylase-ir (TH; catecholaminergic marker in 6-OHDA animals compared to controls. Quantification of protein gene protein 9.5 (pan-neuronal marker positive cardiac fibers showed a significant deficit in 6-OHDA monkeys compared to controls and correlated with TH-ir fiber area. Semi-quantitative evaluation of human leukocyte antigen-ir (inflammatory marker and nitrotyrosine-ir (oxidative stress marker did not show significant changes 3 months post-neurotoxin. Cardiac nerve bundle α-synuclein-ir (presynaptic protein was reduced (trend in 6-OHDA treated monkeys; insoluble proteinase-K resistant α-synuclein (typical of PD pathology was not observed. In the adrenal medulla, 6-OHDA monkeys had significantly reduced TH-ir and aminoacid decarboxylase-ir. Our results confirm that systemic 6-OHDA dosing to nonhuman primates

  2. Magnitude of Morning Surge in Blood Pressure Is Associated with Sympathetic but Not Cardiac Baroreflex Sensitivity

    Science.gov (United States)

    Johnson, Aaron W.; Hissen, Sarah L.; Macefield, Vaughan G.; Brown, Rachael; Taylor, Chloe E.

    2016-01-01

    The ability of the arterial baroreflex to regulate blood pressure may influence the magnitude of the morning surge in blood pressure (MSBP). The aim was to investigate the relationships between sympathetic and cardiac baroreflex sensitivity (BRS) and the morning surge. Twenty-four hour ambulatory blood pressure was recorded in 14 young individuals. The morning surge was defined via the pre-awakening method, which is calculated as the difference between mean blood pressure values 2 h before and 2 h after rising from sleep. The mean systolic morning surge, diastolic morning surge, and morning surge in mean arterial pressures were 15 ± 2, 13 ± 1, and 11 ± 1 mmHg, respectively. During the laboratory protocol, continuous measurements of blood pressure, heart rate, and muscle sympathetic nerve activity (MSNA) were made over a 10-min period of rest. Sympathetic BRS was quantified by plotting MSNA burst incidence against diastolic pressure (sympathetic BRSinc), and by plotting total MSNA against diastolic pressure (sympathetic BRStotal). Cardiac BRS was quantified using the sequence method. The mean values for sympathetic BRSinc, sympathetic BRStotal and cardiac BRS were −1.26 ± 0.26 bursts/100 hb/mmHg, −1.60 ± 0.37 AU/beat/mmHg, and 13.1 ± 1.5 ms/mmHg respectively. Significant relationships were identified between sympathetic BRSinc and the diastolic morning surge (r = 0.62, p = 0.02) and the morning surge in mean arterial pressure (r = 0.57, p = 0.03). Low sympathetic BRS was associated with a larger morning surge in mean arterial and diastolic blood pressure. Trends for relationships were identified between sympathetic BRStotal and the diastolic morning surge (r = 0.52, p = 0.066) and the morning surge in mean arterial pressure (r = 0.48, p = 0.095) but these did not reach significance. There were no significant relationships between cardiac BRS and the morning surge. These findings indicate that the ability of the baroreflex to buffer increases in blood

  3. Sympathetic Activation Does Not Affect the Cardiac and Respiratory Contribution to the Relationship between Blood Pressure and Pial Artery Pulsation Oscillations in Healthy Subjects.

    Directory of Open Access Journals (Sweden)

    Pawel J Winklewski

    Full Text Available Using a novel method called near-infrared transillumination backscattering sounding (NIR-T/BSS that allows for the non-invasive measurement of pial artery pulsation (cc-TQ and subarachnoid width (sas-TQ in humans, we assessed the influence of sympathetic activation on the cardiac and respiratory contribution to blood pressure (BP cc-TQ oscillations in healthy subjects.The pial artery and subarachnoid width response to handgrip (HGT and cold test (CT were studied in 20 healthy subjects. The cc-TQ and sas-TQ were measured using NIR-T/BSS; cerebral blood flow velocity (CBFV was measured using Doppler ultrasound of the left internal carotid artery; heart rate (HR and beat-to-beat mean BP were recorded using a continuous finger-pulse photoplethysmography; respiratory rate (RR, minute ventilation (MV, end-tidal CO2 (EtCO2 and end-tidal O2 (EtO2 were measured using a metabolic and spirometry module of the medical monitoring system. Wavelet transform analysis was used to assess the relationship between BP and cc-TQ oscillations.HGT evoked an increase in BP (+15.9%; P<0.001, HR (14.7; P<0.001, SaO2 (+0.5; P<0.001 EtO2 (+2.1; P<0.05 RR (+9.2%; P = 0.05 and MV (+15.5%; P<0.001, while sas-TQ was diminished (-8.12%; P<0.001, and a clear trend toward cc-TQ decline was observed (-11.0%; NS. CBFV (+2.9%; NS and EtCO2 (-0.7; NS did not change during HGT. CT evoked an increase in BP (+7.4%; P<0.001, sas-TQ (+3.5%; P<0.05 and SaO2(+0.3%; P<0.05. HR (+2.3%; NS, CBFV (+2.0%; NS, EtO2 (-0.7%; NS and EtCO2 (+0.9%; NS remained unchanged. A trend toward decreased cc-TQ was observed (-5.1%; NS. The sas-TQ response was biphasic with elevation during the first 40 seconds (+8.8% vs. baseline; P<0.001 and subsequent decline (+4.1% vs. baseline; P<0.05. No change with respect to wavelet coherence and wavelet phase coherence was found between the BP and cc-TQ oscillations.Short sympathetic activation does not affect the cardiac and respiratory contribution to the relationship

  4. Usefulness of Cardiac Sympathetic Nerve Imaging Using (123)Iodine-Metaiodobenzylguanidine Scintigraphy for Predicting Sudden Cardiac Death in Patients With Heart Failure.

    Science.gov (United States)

    Kasama, Shu; Toyama, Takuji; Kurabayashi, Masahiko

    2016-01-01

    The autonomic nervous system plays an important role in the human heart. Activation of the cardiac sympathetic nervous system is a cardinal pathophysiological abnormality associated with the failing human heart. Myocardial imaging using (123)I-metaiodobenzylguanidine (MIBG), an analog of norepinephrine, can be used to investigate the activity of norepinephrine, the predominant neurotransmitter of the sympathetic nervous system. Many clinical trials have demonstrated that (123)I-MIBG scintigraphic parameters predict cardiac adverse events, especially sudden cardiac death, in patients with heart failure. In this review, we summarize results from published studies that have focused on the use of cardiac sympathetic nerve imaging using (123)I-MIBG scintigraphy for risk stratification of sudden cardiac death in patients with heart failure.

  5. Cardiac sympathetic modulation in response to apneas/hypopneas through heart rate variability analysis.

    Directory of Open Access Journals (Sweden)

    Florian Chouchou

    Full Text Available Autonomic dysfunction is recognized to contribute to cardiovascular consequences in obstructive sleep apnea/hypopnea syndrome (OSAHS patients who present predominant cardiovascular sympathetic activity that persists during wakefulness. Here, we examined 1 the factors that influence sympathetic cardiac modulation in response to apneas/hypopneas; and 2 the influence of autonomic activity during apneas/hypopneas on CA. Sixteen OSAHS patients underwent in-hospital polysomnography. RR interval (RR and RR spectral analysis using wavelet transform were used to study parasympathetic (high frequency power: HF(WV and sympathetic (low frequency power: LF(WV and LF(WV/HF(WV ratio activity before and after apnea/hypopnea termination. Autonomic cardiac modulations were compared according to sleep stage, apnea/hypopnea type and duration, arterial oxygen saturation, and presence of CA. At apnea/hypopnea termination, RR decreased (p<0.001 while LF(WV (p = 0.001 and LF(WV/HF(WV ratio (p = 0.001 increased. Only RR and LF(WV/HF(WV ratio changes were higher when apneas/hypopneas produced CA (p = 0.030 and p = 0.035, respectively or deep hypoxia (p = 0.023 and p = 0.046, respectively. Multivariate statistical analysis showed that elevated LF(WV (p = 0.006 and LF(WV/HF(WV ratio (p = 0.029 during apneas/hypopneas were independently related to higher CA occurrence. Both the arousal and hypoxia processes may contribute to sympathetic cardiovascular overactivity by recurrent cardiac sympathetic modulation in response to apneas/hypopneas. Sympathetic overactivity also may play an important role in the acute central response to apneas/hypopneas, and in the sleep fragmentation.

  6. Effects of adding intravenous nicorandil to standard therapy on cardiac sympathetic nerve activity and myocyte dysfunction in patients with acute decompensated heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Toyama, Takuji; Funada, Ryuichi; Takama, Noriaki; Koitabashi, Norimichi; Kurabayashi, Masahiko [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Ichikawa, Shuichi [Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Suzuki, Yasuyuki; Matsumoto, Naoya [Nihon University School of Medicine, Department of Cardiology, Tokyo (Japan); Sato, Yuichi [Health Park Clinic, Department of Imaging, Takasaki, Gunma (Japan)

    2015-04-01

    Nicorandil, an adenosine triphosphate-sensitive potassium channel opener, improves cardiac sympathetic nerve activity (CSNA) in ischemic heart disease or chronic heart failure. However, its effects on CSNA and myocyte dysfunction in acute heart failure (AHF) remain unclear. We investigated the effects of adding intravenous nicorandil to standard therapy on CSNA and myocyte dysfunction in AHF. We selected 70 patients with mild to moderate nonischemic AHF who were treated with standard conventional therapy soon after admission. Thirty-five patients were assigned to additionally receive intravenous nicorandil (4-12 mg/h; group A), whereas the remaining patients continued their current drug regimen (group B). Delayed total defect score (TDS), delayed heart to mediastinum count (H/M) ratio, and washout rate (WR) were determined by {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy within 3 days of admission and 4 weeks later. High sensitivity troponin T (hs-TnT) level was also measured at the same time points. After treatment, MIBG scintigraphic parameters significantly improved in both groups. However, the extent of the changes in these parameters in group A significantly exceeded the extent of the changes in group B [TDS -11.3 ± 4.3 in group A vs -4.0 ± 6.0 in group B (p < 0.01); H/M ratio 0.31 ± 0.16 vs 0.14 ± 0.16 (p < 0.01); WR -13.8 ± 7.8 % vs -6.1 ± 8.9 % (p < 0.01)]. The hs-TnT level decreased significantly from 0.052 ± 0.043 to 0.041 ± 0.033 ng/ml (p < 0.05) in group A, but showed no significant change in group B. Moreover, in both groups, no relationships between the extent of changes in MIBG parameters and hs-TnT level were observed. Adding intravenous nicorandil to standard therapy provides additional benefits for CSNA and myocyte dysfunction over conventional therapy alone in AHF patients. Furthermore, the mechanisms of improvement in CSNA and myocyte dysfunction after nicorandil treatment in AHF patients were distinct. (orig.)

  7. The clinical value of cardiac sympathetic imaging in heart failure

    DEFF Research Database (Denmark)

    Christensen, Thomas Emil; Kjaer, Andreas; Hasbak, Philip

    2014-01-01

    The autonomic nervous system plays an important role in the pathology of heart failure. The single-photon emission computed tomography tracer iodine-123-metaiodobenzylguanidine ((123) I-MIBG) can be used to investigate the activity of the predominant neurotransmitter of the sympathetic nervous...

  8. Impaired cardiac sympathetic innervation in symptomatic patients with long QT syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kies, Peter; Stegger, Lars; Schober, Otmar [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Paul, Matthias; Moennig, Gerold [University Hospital Muenster, Department for Cardiology and Angiology, Muenster (Germany); Gerss, Joachim [University of Muenster, Institute of Biostatistics and Clinical Research, Muenster (Germany); Wichter, Thomas [Marienhospital Osnabrueck, Department of Cardiology, Niels-Stensen-Kliniken, Osnabrueck (Germany); Schaefers, Michael [University of Muenster, European Institute of Molecular Imaging - EIMI, Muenster (Germany); Schulze-Bahr, Eric [University Hospital Muenster, Department for Cardiology and Angiology, Muenster (Germany); University Hospital Muenster, Institute for Genetics of Heart Diseases, Muenster (Germany)

    2011-10-15

    Increased sympathetic activation is a key modifier for arrhythmogenesis in patients with long QT syndrome (LQTS), a congenital channelopathy. Therefore, we investigated cardiac sympathetic function using {sup 123}I-metaiodobenzylguanidine (MIBG) single photon emission computed tomography (SPECT) in a cohort of symptomatic LQTS patients and correlated these findings with the underlying genotype. [{sup 123}I]MIBG SPECT was performed in 28 LQTS patients. Among these, 18 patients (64%) had a previous syncope and 10 patients (36%) survived sudden cardiac arrest. Patients were characterized in terms of genetic subtypes and QTc interval on surface ECGs. SPECT images were analysed for regional [{sup 123}I]MIBG uptake in a 33-segment bullseye scheme and compared to those obtained from 10 age-matched healthy control subjects (43 {+-} 12 years). An abnormal {sup 123}I-MIBG scan was found in 17 of 28 LQTS patients (61%) with a tracer reduction mainly located in the anteroseptal segments of the left ventricle. This finding was independent of the genetic LQTS subtype. In addition, no differences were found between LQTS patients with a QTc >500 ms vs <500 ms or those suffering from syncope vs VF (p > 0.05). A distinct regional pattern of impaired cardiac sympathetic function was identified in the majority of symptomatic LQTS patients. This innervation defect was independent of the underlying genotype and clinical disease expression. (orig.)

  9. Impaired cardiac sympathetic innervation in symptomatic patients with long QT syndrome

    International Nuclear Information System (INIS)

    Increased sympathetic activation is a key modifier for arrhythmogenesis in patients with long QT syndrome (LQTS), a congenital channelopathy. Therefore, we investigated cardiac sympathetic function using 123I-metaiodobenzylguanidine (MIBG) single photon emission computed tomography (SPECT) in a cohort of symptomatic LQTS patients and correlated these findings with the underlying genotype. [123I]MIBG SPECT was performed in 28 LQTS patients. Among these, 18 patients (64%) had a previous syncope and 10 patients (36%) survived sudden cardiac arrest. Patients were characterized in terms of genetic subtypes and QTc interval on surface ECGs. SPECT images were analysed for regional [123I]MIBG uptake in a 33-segment bullseye scheme and compared to those obtained from 10 age-matched healthy control subjects (43 ± 12 years). An abnormal 123I-MIBG scan was found in 17 of 28 LQTS patients (61%) with a tracer reduction mainly located in the anteroseptal segments of the left ventricle. This finding was independent of the genetic LQTS subtype. In addition, no differences were found between LQTS patients with a QTc >500 ms vs 0.05). A distinct regional pattern of impaired cardiac sympathetic function was identified in the majority of symptomatic LQTS patients. This innervation defect was independent of the underlying genotype and clinical disease expression. (orig.)

  10. Proposal for standardization of I-123-metaiodobenzylguanidine (MIBG) cardiac sympathetic imaging by the EANM Cardiovascular Committee and the European Council of Nuclear Cardiology

    NARCIS (Netherlands)

    A. Flotats; I. Carrio; D. Agostini; D. Le Guludec; C. Marcassa; M. Schaffers; G.A. Somsen; M. Unlu; H.J. Verberne

    2010-01-01

    This proposal for standardization of I-123-metaiodobenzylguanidine (iobenguane, MIBG) cardiac sympathetic imaging includes recommendations for patient information and preparation, radiopharmaceutical, injected activities and dosimetry, image acquisition, quality control, reconstruction methods, atte

  11. Norepinephrine-induced nerve growth factor depletion causes cardiac sympathetic denervation in severe heart failure.

    Science.gov (United States)

    Kimura, Kensuke; Kanazawa, Hideaki; Ieda, Masaki; Kawaguchi-Manabe, Haruko; Miyake, Yoshiko; Yagi, Takashi; Arai, Takahide; Sano, Motoaki; Fukuda, Keiichi

    2010-08-25

    In severe congestive heart failure (CHF), sympathetic overactivity correlates with the exacerbation of cardiac performance. To test the hypothesis that the cardiac sympathetic nerve density dramatically changes with the acceleration of circulating norepinephrine (NE) concentration, we investigated the temporal association of nerve growth factor (NGF) expression in the heart and cardiac sympathetic nerve density during the development of CHF in the continuous NE-infused rats. The animals were analyzed at 0-, 1-, 3-, 7-, 14-, and 28-day after implantation of osmotic pump at a rate of 0.05 mg/kg/hr. The cardiac performance was temporally facilitated in NE-exposed rats at 3-day in accordance with the sympathetic hyper-innervation induced by the augmentation of NGF mRNA expression in the heart. In NE-treated rats, left ventricular end-diastolic pressure was significantly increased after 7-day and marked left ventricular hypertrophy and systemic fluid retention were observed at 28-day. CHF-induced sympathetic overactivity further increased plasma NE concentration in NE-treated rats and finally reached to 16.1+/-5.6 ng/ml at 28-day (control level was 0.39+/-0.1 ng/ml, pcardiac performance. The cardiac sympathetic fiber loss was also confirmed in NE-exposed DBH (dopamine beta-hydroxylase)-Cre/Floxed-EGFP (enhanced green fluorescent protein) mice with severe CHF, in which sympathetic nerve could be traced by EGFP. Our results suggest that the cardiac sympathetic nerve density is strictly regulated by the NGF expression in the heart and long-exposure of high plasma NE concentration caused myocardial NGF reduction, following sympathetic fiber loss in severe CHF animals.

  12. Sympathetic restraint of respiratory sinus arrhythmia: implications for vagal-cardiac tone assessment in humans

    Science.gov (United States)

    Taylor, J. A.; Myers, C. W.; Halliwill, J. R.; Seidel, H.; Eckberg, D. L.

    2001-01-01

    Clinicians and experimentalists routinely estimate vagal-cardiac nerve traffic from respiratory sinus arrhythmia. However, evidence suggests that sympathetic mechanisms may also modulate respiratory sinus arrhythmia. Our study examined modulation of respiratory sinus arrhythmia by sympathetic outflow. We measured R-R interval spectral power in 10 volunteers that breathed sequentially at 13 frequencies, from 15 to 3 breaths/min, before and after beta-adrenergic blockade. We fitted changes of respiratory frequency R-R interval spectral power with a damped oscillator model: frequency-dependent oscillations with a resonant frequency, generated by driving forces and modified by damping influences. beta-Adrenergic blockade enhanced respiratory sinus arrhythmia at all frequencies (at some, fourfold). The damped oscillator model fit experimental data well (39 of 40 ramps; r = 0.86 +/- 0.02). beta-Adrenergic blockade increased respiratory sinus arrhythmia by amplifying respiration-related driving forces (P arrhythmia is mediated simply by vagal-cardiac nerve activity. These results have important implications for clinical and experimental estimation of human vagal cardiac tone.

  13. Renal sympathetic denervation prevents the development of pulmonary arterial hypertension and cardiac dysfunction in dogs.

    Science.gov (United States)

    Hu, Wei; Yu, Sheng-Bo; Chen, Liao; Guo, Rui-Qiang; Zhao, Qing-Yan

    2015-08-01

    The renin-angiotensin-aldosterone system is activated in pulmonary arterial hypertension (PAH) patients, and this activation may have long-term negative effects on the progression of PAH. The purpose of this study was to evaluate the effects of transcatheter renal sympathetic denervation (RSD) on the development of pulmonary arterial hypertension and cardiac dysfunction in dogs using two-dimensional speckle tracking imaging. Twenty-two dogs were randomly divided into three groups: control group (n = 7), PAH group (n = 8), and PAH + RSD group (n = 7). All dogs were assessed using two-dimensional speckle tracking imaging. The ventricular strain, ventricular synchrony, left ventricular (LV) twist, and torsion rate were analyzed to evaluate cardiac function. After 8 weeks, the right ventricular lateral longitudinal strain and the septum longitudinal strain were reduced in the PAH group compared with the control group (p dogs.

  14. Expressions of cardiac sympathetic norepinephrine transporter and β1-adrenergic receptor decreased in aged rats

    Institute of Scientific and Technical Information of China (English)

    He LI; Xiao-qing MA; Fan YE; Jing ZHANG; Xin ZHOU; Zhi-hong WANG; Yu-ming LI; Guo-yuan ZHANG

    2009-01-01

    Evidence suggests that the deterioration of communication between the sympathetic nervous system and cardiovas-cular system always accompanies the aging of human and animals. Cardiac sympathetic norepinephrine (NE) transporter (NET) on presynaptic membrane is a predominant component to eliminate released NE in the synaptic cleff and maintains the sensitivity of the β-adrenergic receptor (β-AR). In the present study, we investigated NET and β1-AR mRNA levels and sympathetic nerve density in cardiac sympathetic ganglion and leff ventricular myocardium in 2- and 16-month-old rats with Northern blot analysis and immunohistochemistry. The expression levels of NET mRNA, NET protein and β1-AR mRNA in the ganglia or myocardia of 16-month-old rats were markedly reduced by 67%, 26%, and 43%, respectively, in comparison with those in 2-month-old rats. Our results also show that aging induces a strong decrease of the catecholaminergic nerve fiber density.

  15. What can we learn about neural control of the cardiovascular system by studying rhythms in sympathetic nerve activity?

    Science.gov (United States)

    Barman, Susan M

    2016-05-01

    Since the first recordings of sympathetic nerve activity in the 1930s, it was very clear that the activity was organized into bursts synchronized to the respiratory and cardiac cycles. Since the early studies, evidence has accumulated showing that sympathetic neural networks are quite complex and generate a variety of periodicities that range between ~0.04 and 10Hz, depending on the physiological state, type of nerve being analyzed, age of the subject, and the species. Despite the ubiquity of sympathetic rhythms, many investigators have failed to consider this oscillatory characteristic of sympathetic nerve activity and instead rely on simply quantifying changes in the level of activity to make decisions about the role of the sympathetic nervous system in mediating certain behaviors. This review highlights work that shows the importance of including an assessment of the frequency characteristics of sympathetic nerve activity. PMID:25681532

  16. Heart failure causes cholinergic transdifferentiation of cardiac sympathetic nerves via gp130-signaling cytokines in rodents.

    Science.gov (United States)

    Kanazawa, Hideaki; Ieda, Masaki; Kimura, Kensuke; Arai, Takahide; Kawaguchi-Manabe, Haruko; Matsuhashi, Tomohiro; Endo, Jin; Sano, Motoaki; Kawakami, Takashi; Kimura, Tokuhiro; Monkawa, Toshiaki; Hayashi, Matsuhiko; Iwanami, Akio; Okano, Hideyuki; Okada, Yasunori; Ishibashi-Ueda, Hatsue; Ogawa, Satoshi; Fukuda, Keiichi

    2010-02-01

    Although several cytokines and neurotrophic factors induce sympathetic neurons to transdifferentiate into cholinergic neurons in vitro, the physiological and pathophysiological roles of this remain unknown. During congestive heart failure (CHF), sympathetic neural tone is upregulated, but there is a paradoxical reduction in norepinephrine synthesis and reuptake in the cardiac sympathetic nervous system (SNS). Here we examined whether cholinergic transdifferentiation can occur in the cardiac SNS in rodent models of CHF and investigated the underlying molecular mechanism(s) using genetically modified mice. We used Dahl salt-sensitive rats to model CHF and found that, upon CHF induction, the cardiac SNS clearly acquired cholinergic characteristics. Of the various cholinergic differentiation factors, leukemia inhibitory factor (LIF) and cardiotrophin-1 were strongly upregulated in the ventricles of rats with CHF. Further, LIF and cardiotrophin-1 secreted from cultured failing rat cardiomyocytes induced cholinergic transdifferentiation in cultured sympathetic neurons, and this process was reversed by siRNAs targeting Lif and cardiotrophin-1. Consistent with the data in rats, heart-specific overexpression of LIF in mice caused cholinergic transdifferentiation in the cardiac SNS. Further, SNS-specific targeting of the gene encoding the gp130 subunit of the receptor for LIF and cardiotrophin-1 in mice prevented CHF-induced cholinergic transdifferentiation. Cholinergic transdifferentiation was also observed in the cardiac SNS of autopsied patients with CHF. Thus, CHF causes target-dependent cholinergic transdifferentiation of the cardiac SNS via gp130-signaling cytokines secreted from the failing myocardium.

  17. Imaging of the autonomic nervous system: focus on cardiac sympathetic innervation.

    Science.gov (United States)

    Goldstein, David S

    2003-12-01

    Symptoms or signs of abnormal autonomic nervous system function occur commonly in several neurological disorders. Clinical evaluations have depended on physiological, pharmacological, and neurochemical approaches. Recently, imaging of sympathetic noradrenergic innervation has been introduced and applied especially in the heart. Most studies have used the radiolabeled sympathomimetic amine, (123)I-metaiodobenzylguanidine. Decreased uptake or increased "washout" of (123)I-metaiodobenzylguanidine-derived radioactivity is associated with worse prognosis or more severe disease in hypertension, congestive heart failure, arrhythmias, and diabetes mellitus. This pattern may reflect a high rate of postganglionic sympathetic nerve traffic to the heart. Many recent studies have agreed on the remarkable finding that all patients with Parkinson's disease and orthostatic hypotension have a loss of cardiac sympathetic innervation, whereas all patients with multiple system atrophy, often difficult to distinguish clinically from Parkinson's disease, have intact cardiac sympathetic innervation. Because Parkinson's disease entails a postganglionic sympathetic noradrenergic lesion, the disease appears to be not only a movement disorder, with dopamine loss in the nigrostriatal system of the brain, but also a dysautonomia, with noradrenaline loss in the sympathetic nervous system of the heart. As new ligands are developed, one may predict further discoveries of involvement of components of the autonomic nervous system in neurological diseases.

  18. Norepinephrine transporter (NET) is expressed in cardiac sympathetic ganglia of adult rat

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The sympathetic nervous system plays a cardinal role in regulating cardiac function through releasing the neurotransmitter norepinephrine (NE). In comparison with central nervous system, the molecular mechanism of NE uptake in myocardium is not clear. In present study, we proved that in rat the CNS type of NE transporter (NET) was also expressed in middle cervical-stellate ganglion complex (MC-SG complex) which is considered to control the activity of heart, but not expressed in myocardium. The results also showed that NET expression level in right ganglion was significantly higher than in the left, rendering the greater capacity of NE uptake in right ventricle, a fact which may contribute to the maintenance of right ventricular function under pathologic state.

  19. Effects of Antidepressants, but not Psychopathology, on Cardiac Sympathetic Control : A Longitudinal Study

    NARCIS (Netherlands)

    Licht, Carmilla M. M.; Penninx, Brenda W. J. H.; de Geus, Eco J. C.

    2012-01-01

    Increased sympathetic activity has been hypothesized to have a role in the elevated somatic disease risk in persons with depressive or anxiety disorders. However, it remains unclear whether increased sympathetic activity reflects a direct effect of anxiety or depression or an indirect effect of anti

  20. Co-localization of histamine and norepinephrine in sympathetic ganglia and exocytosis of endogenous histamine from cardiac sympathetic nerve endings of macaca mulatto monkey

    Institute of Scientific and Technical Information of China (English)

    Ming-kaiLI; Xiao-xingLUO; Liang-weiCHEN; ZhongCHEN; JiaMENG; JingHU; Yu-meiWU; Jing-ruMENG; ZhengHOU; XueMA

    2005-01-01

    AIM To provide the evidence about localization, biosynthesis, metabolism and release of histamine from the cardiac sympathetic nerve terminals, and endogenous sympathetic histamine could inhibit itsel frelease from the nerve terminal through the presynaptic histamine H3 receptor. METHODS Using double-labeled immunohistochemistry to observe the co-localization of histamine and NE in the superior cer-vical ganglia (SCG) of macaca mulatto monkey; Different-speed centrifugation to obtain the cardiac sympathetic nerve terminal model (the cardiac synaptosomes), spectrofluorometer and ELISA techniques to detect the release of histamine from the cardiacsynaptosomes. RESULTS ( 1 ) The coexistence of histamine and norepinephrine immunoreactivities was identified in the same neuron within SCG of macaca mulatto monkey. (2) Depolarization of macaca mulatto monkey cardiac synaptosomes with 50 mmol/L potassium caused the release of endogenous histamine,

  1. [Clinical application of skin sympathetic nerve activity].

    Science.gov (United States)

    Iwase, Satoshi

    2009-03-01

    Skin sympathetic nerve activity (SSNA) is microneurographically recorded from the skin nerve fascicle in the peripheral nerves. It is characterized by the following features: 1) irregular, pulse asynchronous, burst activity with respiratory variation, 2) burst activity followed by vasoconstriction and/or sweating, 3) elicited by mental stress and arousal stimuli, e.g., sound, pain, electric stimulation, 4) burst with longer duration as compared with sympathetic outflow to muscles, and 5) burst activity following sudden inspiratory action. It comprises vasoconstrictor (VC) and sudomotor(SM) activity, as well as vasodilator (VD) activity. VC and SM discharge independently, whereas VD is the same activity with different neurotransmission. The VC and SM are differentiated by effector response, e.g., laser Doppler flowmetry and skin potential changes. SSNA function in thermoregulation in the human body; however it is also elicited by mental stress. SSNA is the lowest at thermoneutral ambient temperature (approximately 27 degrees C), and is enhanced in the pressence of ambient warm and cool air. The burst amplitude is well-correlated to both skin blood flow reduction rate or sweat rate change. The clinical application of SSNA comprises the following: 1) clarification of sweating phenomenon, 2) clarification and diagnosis of anhidrosis, 3) clarification and diagnosis of hyperhidrosis, 4) clarification of thermoregulatory function and diagnosis of thermoregulatory disorder, 5) clarification of pathophysiology and diagnosis of vascular diseases, e.g., Raynaud and Buerger diseases. 6) clarification of the relation between cognitive function and SSNA and 7) determination of pharmacological effect attributable to change in neuroeffector responses. PMID:19301594

  2. Scintigraphic assessment of cardiac sympathetic innervation with I-123-metaiodobenzylguanidine in cardiomyopathy. Special reference to cardiac arrhythmia

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Takahisa; Otsuka, Nobuaki; Sone, Teruki; Mimura, Hiroaki; Yanagimoto, Shinichi; Tomomitsu, Tatsushi; Fukunaga, Masao [Kawasaki Medical School, Kurashiki, Okayama (Japan); Morita, Koichi

    1999-07-01

    Cardiac sympathetic imagings with I-123-metaiodobenzylguanidine (MIBG) were carried out in 5 cases with dilated cardiomyopathy (DCM), 26 cases with hypertrophic cardiomyopathy (HCM), and 4 cases without cardiac disease as a control to assess cardiac sympathetic innervation qualitatively and quantitatively, and to clarify the relation of MIBG accumulation to arrhythmia. MIBG scintigraphy was performed at 15 min. (early image) and 4 hr. (delayed image) after intravenous injection of MIBG 111 MBq. The MIBG uptake ratio of mediastinum (H/M) and the cardiac washout rate (WR) from early to delayed images were calculated. On both early and delayed SPECTs, MIBG uptake was assessed by defect scores (DSs). Regarding the cases with HCM, the MIBG uptake ratio, WR, and DS were also compared in cases with and without arrhythmia. In DCM, the MIBG uptake on delayed SPECT was markedly low, the H/M ratio was significantly lower, and the DS was significantly higher than in the control (all p<0.05). As for the WR, there was no significant difference between HCM, DCM and the control. In HCM, significantly reduced MIBG uptake was observed in cases with ventricular techycardia (VT) and in cases with atrial fibrillation (Af), as compared with cases without arrhythmia (all p<0.05). There results suggest that MIBG scintigraphy might be a useful tool in the assessment of cardiac sympathetic abnormalities in cardiomyopathy, especially in cases with arrhythmia. (author)

  3. Functional coupling with cardiac muscle promotes maturation of hPSC-derived sympathetic neurons

    Science.gov (United States)

    Oh, Yohan; Cho, Gun-Sik; Li, Zhe; Hong, Ingie; Zhu, Renjun; Kim, Min-Jeong; Kim, Yong Jun; Tampakakis, Emmanouil; Tung, Leslie; Huganir, Richard; Dong, Xinzhong; Kwon, Chulan; Lee, Gabsang

    2016-01-01

    Summary Neurons derived from human pluripotent stem cells (hPSCs) are powerful tools for studying human neural development and diseases. Robust functional coupling of hPSC-derived neurons with target tissues in vitro is essential for modeling intercellular physiology in a dish and to further translational studies, but has proven difficult to achieve. Here, we derive sympathetic neurons from hPSCs and show they can form physical and functional connections with cardiac muscle cells. Using multiple hPSC reporter lines, we recapitulated human autonomic neuron development in vitro and successfully isolated PHOX2B:eGFP+ neurons that exhibit sympathetic marker expression and electrophysiological properties, and norepinephrine secretion. Upon pharmacologic and optogenetic manipulation, PHOX:eGFP+ neurons controlled beating rates of cardiomyocytes, and the physical interactions between these cells increased neuronal maturation. This study provides a foundation for human sympathetic neuron specification and for hPSC-based neuronal control of organs in a dish. PMID:27320040

  4. Investigation of Sleep Bruxism Relating to Micro-arousals and Cardiac Sympathetic Activities%夜磨牙与微觉醒及心脏交感神经活动的关系

    Institute of Scientific and Technical Information of China (English)

    刘伟才; 王海波; 陈威; 李强

    2012-01-01

    Objective: To investigate whether rhythmic masticatory muscle activity (RMMA) is associated with sleep micro- arousals (MA), and analyze the association between RMMA of sleep bruxism patients (RMMA/SB) and autonomic cardiac activity. Methods: Thirty SB subjects and thirty control subjects for two consecutive nights were performed by polygraphic recordings. MA index and RMMA index were scored. The mean heart rate from a series of 10 cardiac cycles was calculated at 60, 40, 20 and 5 sec before RMMA onset respectively. To assess a transient beat-to-beat heart rate change in relation to the RMMA onset, heart rate from 5 cardiac cycles before and 5 cycles after the onset were also calculated. Results: Sleep bruxism (SB) subjects showed a higher incidence of rhythmic masticatory muscle activity (RMMA) than control subjects (6.10±1.05 vs. 1.81 ±0.39, P<0.0001). However, no difference was found in according to their micro-arousal index(7.72±1.21 vs.7.53±1.33, P=0.5641). RMMA/SB was associated with sleep micro-arousals. In both groups, transient heart rate acceleration was observed in relation to the onset of RMMA episodes. Conclusion: RMMA is associated with sleep micro-arousals. In SB subjects, a clear increase in sympathetic activity precedes SB onset.%目的:研究夜磨牙(sleep bruxism,SB)患者睡眠期咀嚼肌节律性运动(RMMA)发生的微觉醒机制.方法:对30名夜磨牙患者、30名正常人进行连续2夜的多导睡眠监测,研究RMMA事件与微觉醒(MA)的时间相关性;比较2组间RMMA指数及MA指数的差异;RMMA事件发生前60 s、前40 s、前20 s、前5s,共5个时间点的各连续10个心动周期的平均心率,以及RMMA事件发生前后各5个心动周期的心率变化.结果:夜磨牙症患者微觉醒指数(7.72±1.21)与正常对照相似(7.53±1.33,P=0.5641);但咀嚼肌节律性运动频率,即磨牙指数[(6.10±1.05)次/h]约3倍于正常对照组[(1.81±0.39)次/h,P<0.0001)].RMMA事件与MA存在高度时间相关

  5. Interaction between cardiac sympathetic afferent reflex and chemoreflex is mediated by the NTS AT1 receptors in heart failure.

    Science.gov (United States)

    Wang, Wei-Zhong; Gao, Lie; Wang, Han-Jun; Zucker, Irving H; Wang, Wei

    2008-09-01

    Several sympathoexcitatory reflexes, such as the cardiac sympathetic afferent reflex (CSAR) and arterial chemoreflex, are significantly augmented and contribute to elevated sympathetic outflow in chronic heart failure (CHF). This study was undertaken to investigate the interaction between the CSAR and the chemoreflex in CHF and to further identify the involvement of angiotensin II type 1 receptors (AT1Rs) in the nucleus of the tractus solitarius (NTS) in this interaction. CHF was induced in rats by coronary ligation. Acute experiments were performed in anesthetized rats. The chemoreflex-induced increase in cardiovascular responses was significantly greater in CHF than in sham-operated rats after either chemical or electrical activation of the CSAR. The inhibition of the CSAR by epicardial lidocaine reduced the chemoreflex-induced effects in CHF rats but not in sham-operated rats. Bilateral NTS injection of the AT1R antagonist losartan (10 and 100 pmol) dose-dependently decreased basal sympathetic nerve activity in CHF but not in sham-operated rats. This procedure also abolished the CSAR-induced enhancement of the chemoreflex. The discharge and chemosensitivity of NTS chemosensitive neurons were significantly increased following the stimulation of the CSAR in sham-operated and CHF rats, whereas CSAR inhibition by epicardial lidocaine significantly attenuated chemosensitivity of NTS neurons in CHF but not in sham-operated rats. Finally, the protein expression of AT1R in the NTS was significantly higher in CHF than in sham-operated rats. These results demonstrate that the enhanced cardiac sympathetic afferent input contributes to an excitatory effect of chemoreflex function in CHF, which is mediated by an NTS-AT1R-dependent mechanism.

  6. Chronic central leptin infusion restores cardiac sympathetic-vagal balance and baroreflex sensitivity in diabetic rats

    OpenAIRE

    do Carmo, Jussara M.; Hall, John E.; da Silva, Alexandre A.

    2008-01-01

    This study tested whether leptin restores sympathetic-vagal balance, heart rate (HR) variability, and cardiac baroreflex sensitivity (BRS) in streptozotocin (STZ)-induced diabetes. Sprague-Dawley rats were instrumented with arterial and venous catheters, and a cannula was placed in the lateral ventricle for intracerebroventricular (ICV) leptin infusion. Blood pressure (BP) and HR were monitored by telemetry. BRS and HR variability were estimated by linear regression between HR and BP response...

  7. Cardiac sympathetic denervation preceding motor signs in Parkinson disease

    OpenAIRE

    Goldstein, David S.; Sharabi, Yehonatan; Karp, Barbara I.; Bentho, Oladi; Saleem, Ahmed; Pacak, Karel; Eisenhofer, Graeme

    2007-01-01

    There is substantial interest in identifying biomarkers to detect early Parkinson disease (PD). Cardiac noradrenergic denervation and attenuated baroreflex-cardiovagal function occur in de novo PD, but whether these abnormalities can precede PD has been unknown. Here we report the case of a patient who had profoundly decreased left ventricular myocardial 6-[18F]fluorodopamine-derived radioactivity and low baroreflex-cardiovagal gain, 4 years before the onset of symptoms and signs of PD. The r...

  8. Adipose afferent reflex: sympathetic activation and obesity hypertension.

    Science.gov (United States)

    Xiong, X-Q; Chen, W-W; Zhu, G-Q

    2014-03-01

    Excessive sympathetic activity contributes to the pathogenesis of hypertension and the progression of the related organ damage. Adipose afferent reflex (AAR) is a sympatho-excitatory reflex that the afferent activity from white adipose tissue (WAT) increases sympathetic outflow and blood pressure. Hypothalamic paraventricular nucleus (PVN or PVH) is one of the central sites in the control of the AAR, and ionotropic glutamate receptors in the nucleus mediate the AAR. The AAR is enhanced in obesity and obesity hypertension. Enhanced WAT afferent activity and AAR contribute to the excessive sympathetic activation and hypertension in obesity. Blockage of the AAR attenuates the excessive sympathetic activity and hypertension. Leptin may be one of sensors in the WAT for the AAR, and is involved in the enhanced AAR in obesity and hypertension. This review focuses on the neuroanatomical basis and physiological functions of the AAR, and the important role of the enhanced AAR in the pathogenesis of obesity hypertension.

  9. Receptor-mediated regional sympathetic nerve activation by leptin.

    OpenAIRE

    Haynes, W G; Morgan, D A; Walsh, S A; Mark, A L; Sivitz, W I

    1997-01-01

    Leptin is a peptide hormone produced by adipose tissue which acts centrally to decrease appetite and increase energy expenditure. Although leptin increases norepinephrine turnover in thermogenic tissues, the effects of leptin on directly measured sympathetic nerve activity to thermogenic and other tissues are not known. We examined the effects of intravenous leptin and vehicle on sympathetic nerve activity to brown adipose tissue, kidney, hindlimb, and adrenal gland in anesthetized Sprague-Da...

  10. Centrally administered glucagon stimulates sympathetic nerve activity in rat.

    Science.gov (United States)

    Krzeski, R; Czyzyk-Krzeska, M F; Trzebski, A; Millhorn, D E

    1989-12-18

    The effect of pancreatic glucagon given intravenously, intracerebroventricularly and microinjected into the nucleus of the solitary tract on sympathetic activity in the cervical trunk and adrenal nerve was examined in rat. In each case glucagon caused a relatively long-lasting substantial increase in discharge of both nerves. This finding shows that glucagon can act centrally to stimulate sympathetic activity. The most probable site for the sympathoexcitatory effect of glucagon is the nucleus of the solitary tract. PMID:2598031

  11. Reactive oxygen species in paraventricular nucleus involved in cardiac sympathetic afferent reflex in rats

    Institute of Scientific and Technical Information of China (English)

    Feng Zhang; Yang Yu; Ying Zhang; Yingchun Li; Luqing Zhang; Lingling Fan; Yingya Gao; Guoqing Zhu

    2005-01-01

    Objective: The present study was designed to determine if reactive oxygen species (ROS) in the paraventricularnucleus (PVN) were involved in modulating cardiac sympathetic afferent reflex (CSAR) in anesthetized rats. Methods: Malondialdehyde(MDA), the end product of lipid peroxidation, in the PVN, was determined by thiobarbituric acid (TBA) spectrometric method. Renalsympathetic nerve activity (RSNA) and arterial pressure were recorded in sinoaortic-denervated and cervical-vagotomized rats. The CSARwas evaluated by the response of the RSNA evoked by epicardial application of bradykinin (BK, 0.4 μg). Results: The MDA in the PVNwas significantly increased after epicardial application of BK compared with control (2.0 + 0.3 vs 0.8 + 0.1 nmol/mg protein, P < 0.01 ).Microinjectionof a superoxide anion scavenger, tiron (20 nmol) into the PVN significantly inhibited the CSAR evoked by BK (12.3 ± 1.9vs 4.2+ 1.2%, P < 0.01) and decreased MDA level (1.9±0.3 vs 0.6+0.1 nmol/mg protein, P <0.01) compared with control.Conclusion: The ROS in the PVN is involved in modulating the CSAR in rats.

  12. Angiotensin II and angiotensin-(1-7 in paraventricular nucleus modulate cardiac sympathetic afferent reflex in renovascular hypertensive rats.

    Directory of Open Access Journals (Sweden)

    Hai-Jian Sun

    Full Text Available BACKGROUND: The enhanced cardiac sympathetic afferent reflex (CSAR is involved in the sympathetic activation that contributes to the pathogenesis and progression of hypertension. Activation of AT(1 receptors by angiotension (Ang II in the paraventricular nucleus (PVN augments the enhanced CSAR and sympathetic outflow in hypertension. The present study is designed to determine whether Ang-(1-7 in PVN plays the similar roles as Ang II and the interaction between Ang-(1-7 and Ang II on CSAR in renovascular hypertension. METHODOLOGY/PRINCIPAL FINDINGS: The two-kidney, one-clip (2K1C method was used to induce renovascular hypertension. The CSAR was evaluated by the renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP responses to epicardial application of capsaicin in sinoaortic-denervated and cervical-vagotomized rats with urethane and α-chloralose anesthesia. Either Ang II or Ang-(1-7 in PVN caused greater increases in RSNA and MAP, and enhancement in CSAR in 2K1C rats than in sham-operated (Sham rats. Mas receptor antagonist A-779 and AT(1 receptor antagonist losartan induced opposite effects to Ang-(1-7 or Ang II respectively in 2K1C rats, but losartan had no effects in Sham rats. Losartan but not the A-779 abolished the effects of Ang II, while A-779 but not the losartan blocked the effects of Ang-(1-7. PVN pretreatment with Ang-(1-7 dose-dependently augmented the RSNA, MAP, and CSAR responses to the Ang II in 2K1C rats. Ang II level, AT(1 receptor and Mas receptor protein expression in PVN increased in 2K1C rats compared with Sham rats but Ang-(1-7 level did not. CONCLUSIONS: Ang-(1-7 in PVN is as effective as Ang II in enhancing the CSAR and increasing sympathetic outflow and both endogenous Ang-(1-7 and Ang II in PVN contribute to the enhanced CSAR and sympathetic outflow in renovascular hypertension. Ang-(1-7 in PVN potentiates the effects of Ang II in renovascular hypertension.

  13. Role of sympathetic nerve activity in the process of fainting

    Directory of Open Access Journals (Sweden)

    Satoshi eIwase

    2014-09-01

    Full Text Available Syncope is defined as a transient loss of consciousness and postural tone, characterized by rapid onset, short duration, and spontaneous recovery, and the process of syncope progression will be described with two types of sympathetic change. Simultaneous recordings of microneurographically recorded MSNA and continuous and noninvasive blood pressure measurement have disclose what is going on in the course of progression of the syncope. Vasovagal or neurally mediated syncope, three stages are identified in the course of syncope onset, oscillation, imbalance, and catastrophe phases. The vasovagal syncope is characterized by the sympathoexcitation, followed by vagal overcome via the Bezold-Jarisch reflex. Orthostatic syncope is caused by the response failure or lack of sympathetic nerve activity toward the orthostatic challenge followed by the fluid shift, and subsequent cerebral low perfusion. Four causes are considered for the compensatory failure, which triggers the orthostatic syncope; hypovolemia, increased pooling in the lower body, failure to activate the sympathetic activity, and failure of vasoconstriction against sympathetic vasoconstrictive stimulation. Many pathophysiological conditions were described in the viewpoint of 1 exaggerated sympathoexcitation and 2 failure to activate the sympathetic nerve. We conclude that the sympathetic nervous system can control the cardiovascular function, and its failure resulted syncope, however, responses of the system by microneurographically recorded MSNA would determine the pathophysiology of the onset and progression of syncope, explaining the treatment effect that could be achieved by the analysis of this mechanism.

  14. Effects of leptin on sympathetic nerve activity in conscious mice

    OpenAIRE

    Morgan, Donald A.; Despas, Fabien; Rahmouni, Kamal

    2015-01-01

    The adipocyte-derived hormone, leptin, has emerged as an important regulator of regional sympathetic nerve activity (SNA) with pathophysiological implications in obesity. Genetically engineered mice are useful to understand the molecular pathways underlying the SNA responses evoked by leptin. However, so far the effect of leptin on direct SNA in mice has been studied under general anesthesia. Here, we examined the sympathetic responses evoked by leptin in conscious mice. Mice were instrumente...

  15. Prognostic value of sympathetic innervation and cardiac asynchrony in dilated cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Manrique, Alain; Hitzel, Anne; Vera, Pierre [Rouen University Hospital - Henri Becquerel Center, Nuclear Medicine, Rouen (France); Bernard, Mathieu; Bauer, Fabrice [Rouen University Hospital, Cardiology, Rouen (France); Menard, Jean-Francois [Rouen University Hospital, Biostatistics, Rouen (France); Sabatier, Remi [Caen University Hospital, Cardiology, Caen (France); Jacobson, Arnold [GE Healthcare, Princeton, NJ (United States); Agostini, Denis [Caen University Hospital, Nuclear Medicine, Caen (France)

    2008-11-15

    The purpose of the study is to examine prognostic values of cardiac I-123 metaiodobenzylguanidine (MIBG) uptake and cardiac dyssynchrony in patients with dilated cardiomyopathy (DCM). Ninety-four patients with non-ischemic DCM underwent I-123 MIBG imaging for assessing cardiac sympathetic innervation and equilibrium radionuclide angiography. Mean phase angles and SD of the phase histogram were computed for both right ventricular (RV) and left ventricular (LV). Phase measures of interventricular (RV-LV) and intraventricular (SD-RV and SD-LV) asynchrony were computed. Most patients were receiving beta-blockers (89%) and angiotensin-converting enzyme inhibitors (88%). One patient (1%) was lost to follow-up, six had cardiac death (6.4%), eight had heart transplantation (8.6%), and seven had unplanned hospitalization for heart failure (7.5%; mean follow-up: 37 {+-} 16 months). Patients with poor clinical outcome were older, had higher The New York Heart Association functional class, impaired right ventricular ejection fraction and left ventricular ejection fraction, and impaired cardiac I-123 MIBG uptake. On multivariate analysis, I-123 MIBG heart-to-mediastinum (H/M) uptake ratio <1.6 was the only predictor of both primary (cardiac death or heart transplantation, RR = 7.02, p < 0.01) and secondary (cardiac death, heart transplantation, or recurrent heart failure, RR = 8.10, p = 0.0008) end points. In patients receiving modern medical therapy involving beta-blockers, I-123 MIBG uptake, but not intra-LV asynchrony, was predictive of clinical outcome. The impact of beta-blockers on the prognostic value of ventricular asynchrony remains to be clarified. (orig.)

  16. Alterations of left ventricular deformation and cardiac sympathetic derangement in patients with systolic heart failure: a 3D speckle tracking echocardiography and cardiac {sup 123}I-MIBG study

    Energy Technology Data Exchange (ETDEWEB)

    Leosco, Dario; Parisi, Valentina; Pagano, Gennaro; Femminella, Grazia Daniela; Bevilacqua, Agnese; Formisano, Roberto; Ferro, Gaetana; De Lucia, Claudio; Ferrara, Nicola [University Federico II, Department of Translational Medical Science, Naples (Italy); Pellegrino, Teresa [Italian National Research Council (CNR), Institute of Biostructure and Bioimaging, Naples (Italy); University Federico II, Department of Advanced Biomedical Science, Naples (Italy); Paolillo, Stefania [University Federico II, Department of Advanced Biomedical Science, Naples (Italy); SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Prastaro, Maria; Filardi, Pasquale Perrone; Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Science, Naples (Italy); Rengo, Giuseppe [University Federico II, Department of Translational Medical Science, Naples (Italy); Salvatore Maugeri Foundation, IRCCS, Istituto di Telese, Benevento, BN (Italy)

    2015-09-15

    Myocardial contractile function is under the control of cardiac sympathetic activity. Three-dimensional speckle tracking echocardiography (3D-STE) and cardiac imaging with {sup 123}I-metaiodobenzylguanidine ({sup 123}I-MIBG) are two sophisticated techniques for the assessment of left ventricular (LV) deformation and sympathetic innervation, respectively, which offer important prognostic information in patients with heart failure (HF). The purpose of this investigation was to explore, in patients with systolic HF, the relationship between LV deformation assessed by 3D-STE and cardiac sympathetic derangement evaluated by {sup 123}I-MIBG imaging. We prospectively studied 75 patients with systolic HF. All patients underwent a 3D-STE study (longitudinal, circumferential, area and radial) and {sup 123}I-MIBG planar and SPECT cardiac imaging. 3D-STE longitudinal, circumferential and area strain values were correlated with {sup 123}I-MIBG late heart to mediastinum (H/M) ratio and late SPECT total defect score. After stratification of the patients according to ischaemic or nonischaemic HF aetiology, we observed a good correlation of all 3D-STE measurements with late H/M ratio and SPECT data in the ischaemic group, but in patients with HF of nonischaemic aetiology, no correlation was found between LV deformation and cardiac sympathetic activity. At the regional level, the strongest correlation between LV deformation and adrenergic innervation was found for the left anterior descending coronary artery distribution territory for all four 3D-STE values. In multivariate linear regression analyses, including age, gender, LV ejection fraction, NYHA class, body mass index, heart rate and HF aetiology, only 3D-STE area and radial strain values significantly predicted cardiac sympathetic derangement on {sup 123}I-MIBG late SPECT. This study indicated that 3D-STE measurements are correlated with {sup 123}I-MIBG planar and SPECT data. Furthermore, 3D-STE area and radial strain values

  17. Baroreflex control of sympathetic activity in experimental hypertension

    Directory of Open Access Journals (Sweden)

    M.C.C. Irigoyen

    1998-09-01

    Full Text Available The arterial baroreceptor reflex system is one of the most powerful and rapidly acting mechanisms for controlling arterial pressure. The purpose of the present review is to discuss data relating sympathetic activity to the baroreflex control of arterial pressure in two different experimental models: neurogenic hypertension by sinoaortic denervation (SAD and high-renin hypertension by total aortic ligation between the renal arteries in the rat. SAD depresses baroreflex regulation of renal sympathetic activity in both the acute and chronic phases. However, increased sympathetic activity (100% was found only in the acute phase of sinoaortic denervation. In the chronic phase of SAD average discharge normalized but the pattern of discharges was different from that found in controls. High-renin hypertensive rats showed overactivity of the renin angiotensin system and a great depression of the baroreflexes, comparable to the depression observed in chronic sinoaortic denervated rats. However, there were no differences in the average tonic sympathetic activity or changes in the pattern of discharges in high-renin rats. We suggest that the difference in the pattern of discharges may contribute to the increase in arterial pressure lability observed in chronic sinoaortic denervated rats.

  18. Mechanisms mediating renal sympathetic nerve activation in obesity-related hypertension.

    Science.gov (United States)

    Chen, W; Leo, S; Weng, C; Yang, X; Wu, Y; Tang, X

    2015-04-01

    Excessive renal sympathetic nerve activation may be one of the mechanisms underlying obesity-related hypertension. Impaired baroreflex sensitivity, adipokine disorders-such as leptin, adiponectin, and resistin-activation of the renin-angiotensin system, hyperinsulinemia, insulin resistance, and renal sodium retention present in obesity increase renal sympathetic nerve activity, thus contributing to the development of hypertension. Renal sympathetic denervation reduces both renal sympathetic activity and blood pressure in patients with obesity-related hypertension. PMID:24609799

  19. Periodic Repolarisation Dynamics: A Natural Probe of the Ventricular Response to Sympathetic Activation

    Science.gov (United States)

    Rizas, Konstantinos D; Hamm, Wolfgang; Kääb, Stefan; Schmidt, Georg; Bauer, Axel

    2016-01-01

    Periodic repolarisation dynamics (PRD) refers to low-frequency (≤0.1Hz) modulations of cardiac repolarisation instability. Spontaneous PRD can be assessed non-invasively from 3D high-resolution resting ECGs. Physiological and experimental studies have indicated that PRD correlates with efferent sympathetic nerve activity, which clusters in low-frequency bursts. PRD is increased by physiological provocations that lead to an enhancement of sympathetic activity, whereas it is suppressed by pharmacological β-blockade. Electrophysiological studies revealed that PRD occurs independently from heart rate variability. Increased PRD under resting conditions is a strong predictor of mortality in post-myocardial infarction (post-MI) patients, yielding independent prognostic value from left-ventricular ejection fraction (LVEF), heart rate variability, the Global Registry of Acute Coronary Events score and other established risk markers. The predictive value of PRD is particularly strong in post-MI patients with preserved LVEF (>35 %) in whom it identifies a new high-risk group of patients. The upcoming Implantable Cardiac Monitors in High-Risk Post-Infarction Patients with Cardiac Autonomic Dysfunction and Moderately Reduced Left Ventricular Ejection Fraction (SMART-MI) trial will test prophylactic strategies in high-risk post-MI patients with LVEF 36–50 % identified by PRD and deceleration capacity of heart rate (NCT02594488). PMID:27403291

  20. Effects of leptin on sympathetic nerve activity in conscious mice.

    Science.gov (United States)

    Morgan, Donald A; Despas, Fabien; Rahmouni, Kamal

    2015-09-01

    The adipocyte-derived hormone, leptin, has emerged as an important regulator of regional sympathetic nerve activity (SNA) with pathophysiological implications in obesity. Genetically engineered mice are useful to understand the molecular pathways underlying the SNA responses evoked by leptin. However, so far the effect of leptin on direct SNA in mice has been studied under general anesthesia. Here, we examined the sympathetic responses evoked by leptin in conscious mice. Mice were instrumented, under ketamine/xylazine anesthesia, with renal or lumbar SNA recordings using a thin (40 gauge) bipolar platinum-iridium wire. The electrodes were exteriorized at the nape of the neck and mice were allowed (5 h) to recover from anesthesia. Interestingly, the reflex increases in renal and lumbar SNA caused by sodium nitroprusside (SNP)-induced hypotension was higher in the conscious phase versus the anesthetized state, whereas the increase in both renal and lumbar SNA evoked by leptin did not differ between anesthetized or conscious mice. Next, we assessed whether isoflurane anesthesia would yield a better outcome. Again, the SNP-induced increase in renal SNA and baroreceptor-renal SNA reflex were significantly elevated in the conscious states relative to isoflurane-anesthetized phase, but the renal SNA response induced by leptin in the conscious states were qualitatively comparable to those evoked above. Thus, despite improvement in sympathetic reflexes in conscious mice the sympathetic responses evoked by leptin mimic those induced during anesthesia. PMID:26381017

  1. Association between left ventricular regional sympathetic denervation and mechanical dyssynchrony in phase analysis: a cardiac CZT study

    Energy Technology Data Exchange (ETDEWEB)

    Gimelli, Alessia; Genovesi, Dario; Giorgetti, Assuero; Kusch, Annette [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Liga, Riccardo [Scuola Superiore Sant' Anna, Pisa (Italy); Marzullo, Paolo [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); CNR, Institute of Clinical Physiology, Pisa (Italy)

    2014-05-15

    To evaluate the relationships among myocardial sympathetic innervation, perfusion and mechanical synchronicity assessed with cardiac cadmium-zinc-telluride (CZT) scintigraphy. A group of 29 patients underwent an evaluation of myocardial perfusion with {sup 99m}Tc-tetrofosmin CZT scintigraphy and adrenergic innervation with {sup 123}I-metaiodobenzylguanidine (MIBG) CZT scintigraphy. The summed rest score (SRS), motion score (SMS) and thickening score (STS), as well as the summed {sup 123}I-MIBG defect score (SS-MIBG), were determined. Regional tracer uptake for both {sup 99m}Tc-tetrofosmin and {sup 123}I-MIBG was also calculated. Finally, the presence of significant myocardial mechanical dyssynchrony was evaluated in phase analysis on gated CZT images and the region of latest mechanical activation identified. Significant mechanical dyssynchrony was present in 17 patients (59 %) and associated with higher SRS (P = 0.030), SMS (P < 0.001), STS (P = 0.003) and early SS-MIBG (P = 0.037) as well as greater impairments in left ventricular ejection fraction (P < 0.001) and end-diastolic volume (P < 0.001). In multivariate analysis a higher end-diastolic volume remained the only predictor of mechanical dyssynchrony (P = 0.047). Interestingly, while in the whole population regional myocardial perfusion and adrenergic activity were strongly correlated (R = 0.68), in patients with mechanical dyssynchrony the region of latest mechanical activation was predicted only by greater impairment in regional {sup 123}I-MIBG uptake (P = 0.012) that overwhelmed the effect of depressed regional perfusion. Left ventricular mechanical dyssynchrony is associated with greater depression in contractile function and greater impairments in regional myocardial perfusion and sympathetic activity. In patients with dyssynchrony, the region of latest mechanical activation is characterized by a significantly altered adrenergic tone. (orig.)

  2. Efeito do carvedilol a curto prazo na atividade simpática cardíaca pela cintilografia com 123I-MIBG Effects of short-term carvedilol on the cardiac sympathetic activity assessed by 123I-MIBG scintigraphy

    Directory of Open Access Journals (Sweden)

    Sandra Marina Ribeiro de Miranda

    2010-03-01

    Full Text Available FUNDAMENTO: Alterações autonômicas na insuficiência cardíaca estão associadas a um aumento da morbimortalidade. Vários métodos não invasivos têm sido empregados para avaliar a função simpática, incluindo a imagem cardíaca com 123I-MIBG. OBJETIVO: Avaliar a atividade simpática cardíaca, por meio da cintilografia com 123I-MIBG, antes e após três meses de terapia com carvedilol em pacientes com insuficiência cardíaca com fração de ejeção do VE BACKGROUND: Autonomic alterations in heart failure are associated with an increase in morbimortality. Several noninvasive methods have been employed to evaluate the sympathetic function, including the Meta-Iodobenzylguanidine (123I-MIBG scintigraphy imaging of the heart. OBJECTIVE: to evaluate the cardiac sympathetic activity through 123I-MIBG scintigraphy, before and after three months of carvedilol therapy in patients with heart failure and left ventricular ejection fraction (LVEF < 45%. PATIENTS AND METHODS: Sixteen patients, aged 56.3 ± 12.6 years (11 males, with a mean LVEF of 28% ± 8% and no previous use of beta-blockers were recruited for the study. Images of the heart innervation were acquired with 123I-MIBG, and the serum levels of catecholamines (epinephrine, dopamine and norepinephrine were measured; the radioisotope ventriculography (RIV was performed before and after a three-month therapy with carvedilol. RESULTS: Patients' functional class showed improvement: before the treatment, 50% of the patients were FC II and 50% were FC III. After 3 months, 7 patients were FC I (43.8% and 9 were FC II (56.2%, (p = 0.0001. The mean LVEF assessed by RIV increased from 29% to 33% (p = 0.017. There was no significant variation in cardiac adrenergic activity assessed by 123I-MIBG (early and late resting images and washout rate. No significant variation was observed regarding the measurement of catecholamines. CONCLUSION: The short-term treatment with carvedilol promoted the clinical

  3. Effects of renal sympathetic denervation on post-myocardial infarction cardiac remodeling in rats.

    Directory of Open Access Journals (Sweden)

    Jialu Hu

    Full Text Available OBJECTIVE: To investigate the therapeutic effects of renal denervation (RD on post- myocardial infarction (MI cardiac remodeling in rats, the most optimal time for intervention and the sustainability of these effects. METHODS: One hundred SPF male Wistar rats were randomly assigned to N group (Normal, n=10, MI group(MI, n=20,RD group (RD, n=10, RD3+MI (MI three days after RD, n=20, MI1+RD (RD one day after MI, n=20, MI7+RD (RD seven days after MI, n=20. MI was produced through thoracotomic ligation of the anterior descending artery. RD was performed through laparotomic stripping of the renal arteriovenous adventitial sympathetic nerve. Left ventricular function, hemodynamics, plasma BNP, urine volume, urine sodium excretion and other indicators were measured four weeks after MI. RESULTS: (1 The left ventricular function of the MI group significantly declined (EF<40%, plasma BNP was elevated, urine output was significantly reduced, and 24-hour urine sodium excretion was significantly reduced. (2 Denervation can be achieved by surgically stripping the arteriovenous adventitia, approximately 3 mm from the abdominal aorta. (3 In rats with RD3+MI, MI1+RD and MI7+RD, compared with MI rats respectively, the LVEF was significantly improved (75 ± 8.4%,69 ± 3.8%,73 ± 5.5%, hemodynamic indicators were significantly improved, plasma BNP was significantly decreased, and the urine output was significantly increased (21.3 ± 5 ml,23.8 ± 5.4 ml,25.2 ± 8.7 ml. However, the urinary sodium excretion also increased but without significant difference. CONCLUSIONS: RD has preventive and therapeutic effects on post-MI cardiac remodeling.These effects can be sustained for at least four weeks, but there were no significant differences between denervation procedures performed at different times in the course of illness. Cardiac function, hemodynamics, urine volume and urine sodium excretion in normal rats were not affected by RD.

  4. Prognostic value of myocardial sympathetic activity in patients with asymptomatic myocardial infarction

    International Nuclear Information System (INIS)

    To clarify the significance of myocardial sympathetic activity in patients with asymptomatic myocardial infarction (MI), we performed 123I-metaiodobenzyl-guanidine (MIBG) and 201Tl imaging at rest. We calculated the ratio of cardiac uptake of the isotope to the total injected dose (%Uptake), percent washout of MIBG over 3 hours and the Uptake Ratio (UR, %Uptake of MIBG divided by %Uptake of 201Tl). We compared these indices with clinical findings, exercise stress-rest myocardial perfusion imaging with 99Tc-methoxy-2-isobutyl isonitrile, coronary angiography, echocardiography and neurohumoral findings. During the follow-up period of 19.9±10.3 months in 32 patients, events (heart failure or cardiac death) developed in 10 (31%). In univariate analysis, diabetes mellitus, atrial fibrillation, left ventricular end-diastolic dimension (LVDd) greater than 54 mm, and the %Uptake of MIBG and UR differed significantly between event and event-free groups. Cox proportional hazard model showed that the UR was a predictor of events (p=0.0007). In patients with UR less than 0.58, the relative risk of events was 19.1 times greater than in patients with an UR greater than 0.58. UR was closely correlated to LVDd (r=-0.578, p=0.01) suggesting that myocardial sympathetic activity is related to LV remodeling after MI. MIBG imaging provides important information regarding the prognosis and the pathophysiologic process of asymptomatic MI. (author)

  5. Prognostic value of myocardial sympathetic activity in patients with asymptomatic myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Narita, Michihiro; Kurihara, Tadashi; Sindoh, Takashi; Sawada, Yoshihiro [Sumitomo Hospital, Osaka (Japan)

    1999-04-01

    To clarify the significance of myocardial sympathetic activity in patients with asymptomatic myocardial infarction (MI), we performed {sup 123}I-metaiodobenzyl-guanidine (MIBG) and {sup 201}Tl imaging at rest. We calculated the ratio of cardiac uptake of the isotope to the total injected dose (%Uptake), percent washout of MIBG over 3 hours and the Uptake Ratio (UR, %Uptake of MIBG divided by %Uptake of {sup 201}Tl). We compared these indices with clinical findings, exercise stress-rest myocardial perfusion imaging with {sup 99}Tc-methoxy-2-isobutyl isonitrile, coronary angiography, echocardiography and neurohumoral findings. During the follow-up period of 19.9{+-}10.3 months in 32 patients, events (heart failure or cardiac death) developed in 10 (31%). In univariate analysis, diabetes mellitus, atrial fibrillation, left ventricular end-diastolic dimension (LVDd) greater than 54 mm, and the %Uptake of MIBG and UR differed significantly between event and event-free groups. Cox proportional hazard model showed that the UR was a predictor of events (p=0.0007). In patients with UR less than 0.58, the relative risk of events was 19.1 times greater than in patients with an UR greater than 0.58. UR was closely correlated to LVDd (r=-0.578, p=0.01) suggesting that myocardial sympathetic activity is related to LV remodeling after MI. MIBG imaging provides important information regarding the prognosis and the pathophysiologic process of asymptomatic MI. (author)

  6. Non-invasive assessment of the effect of cardiac sympathetic innervation on metabolism of the human heart

    Energy Technology Data Exchange (ETDEWEB)

    Bengel, F.M.; Ziegler, S.I.; Nekolla, S.G.; Odaka, K.; Schwaiger, M. [Muenchen Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Ueberfuhr, P.; Reichart, B. [Muenchen Univ. (Germany). Herzchirurgische Klinik

    2000-11-01

    The role of cardiac sympathetic nerves in the regulation of myocardial metabolism is not well defined. Owing to the presence of incomplete reinnervation, heart transplant recipients provide a unique model to study the effects of efferent sympathetic innervation. Using this model, we sought to determine the influence of cardiac sympathetic signals on substrate utilisation and overall oxidative metabolism. In 21 transplant recipients, positron emission tomography was applied to determine sympathetic innervation with the noradrenaline analogue carbon-11 hydroxyephedrine, oxidative metabolism with carbon-11 acetate (n=14), and glucose utilisation with fluorine-18 fluorodeoxyglucose (n=7). The reinnervated area comprised 22%{+-}20% of the left ventricle. Oxidative metabolism was similar in denervated and reinnervated myocardium [0.06{+-}0.01 vs 0.06{+-}0.01/min for k(mono)], while glucose uptake was significantly higher in denervated myocardium (6.9{+-}6.6 vs 6.0{+-}6.2 {mu}mol/min/100 g; P=0.03). Reinnervation mainly occurred in the territory of the left anterior descending artery, where retention of {sup 11}C-hydroxyephedrine (6.8{+-}2.7%/min) was higher compared with territories of the left circumflex (4.1{+-}1.7%/min; P<0.01) and right coronary (3.8{+-}1.1%/min; P<0.01) arteries. Oxidative metabolism was similar in all three territories, but compared with the reinnervated territory of the left anterior descending artery (53%{+-}16% of maximum), relative FDG uptake was higher in territories of the left circumflex (76%{+-}6%, P<0.01) and right coronary (67%{+-}10%, P<0.05) arteries. Similar degrees of regional heterogeneity were not observed in normals. Thus, while overall energy production through oxidative metabolism remains unaffected, cardiac utilisation of glucose in the fasting state is increased in the absence of catecholamine uptake sites. Innervated myocardium, however, may preferentially utilise free fatty acids, suggesting a role for sympathetic tone in

  7. Cardiac sympathetic denervation in patients with refractory ventricular arrhythmias or electrical storm: Intermediate and long-term follow-up

    OpenAIRE

    Vaseghi, M; Gima, J; Kanaan, C; Ajijola, OA; Marmureanu, A; Mahajan, A.; Shivkumar, K

    2014-01-01

    Background Left and bilateral cardiac sympathetic denervation (CSD) have been shown to reduce burden of ventricular arrhythmias acutely in a small number of patients with ventricular tachyarrhythmia (VT) storm. The effects of this procedure beyond the acute setting are unknown. Objective The purpose of this study was to evaluate the intermediate and long-term effects of left and bilateral CSD in patients with cardiomyopathy and refractory VT or VT storm. Methods Retrospective analysis of medi...

  8. Swimming training increases cardiac vagal activity and induces cardiac hypertrophy in rats

    Directory of Open Access Journals (Sweden)

    A. Medeiros

    2004-12-01

    Full Text Available The effect of swimming training (ST on vagal and sympathetic cardiac effects was investigated in sedentary (S, N = 12 and trained (T, N = 12 male Wistar rats (200-220 g. ST consisted of 60-min swimming sessions 5 days/week for 8 weeks, with a 5% body weight load attached to the tail. The effect of the autonomic nervous system in generating training-induced resting bradycardia (RB was examined indirectly after cardiac muscarinic and adrenergic receptor blockade. Cardiac hypertrophy was evaluated by cardiac weight and myocyte morphometry. Plasma catecholamine concentrations and citrate synthase activity in soleus muscle were also determined in both groups. Resting heart rate was significantly reduced in T rats (355 ± 16 vs 330 ± 20 bpm. RB was associated with a significantly increased cardiac vagal effect in T rats (103 ± 25 vs 158 ± 40 bpm, since the sympathetic cardiac effect and intrinsic heart rate were similar for the two groups. Likewise, no significant difference was observed for plasma catecholamine concentrations between S and T rats. In T rats, left ventricle weight (13% and myocyte dimension (21% were significantly increased, suggesting cardiac hypertrophy. Skeletal muscle citrate synthase activity was significantly increased by 52% in T rats, indicating endurance conditioning. These data suggest that RB induced by ST is mainly mediated parasympathetically and differs from other training modes, like running, that seems to mainly decrease intrinsic heart rate in rats. The increased cardiac vagal activity associated with ST is of clinical relevance, since both are related to increased life expectancy and prevention of cardiac events.

  9. Involvement of Hypothalamic AMP-Activated Protein Kinase in Leptin-Induced Sympathetic Nerve Activation

    OpenAIRE

    Mamoru Tanida; Naoki Yamamoto; Toshishige Shibamoto; Kamal Rahmouni

    2013-01-01

    In mammals, leptin released from the white adipose tissue acts on the central nervous system to control feeding behavior, cardiovascular function, and energy metabolism. Central leptin activates sympathetic nerves that innervate the kidney, adipose tissue, and some abdominal organs in rats. AMP-activated protein kinase (AMPK) is essential in the intracellular signaling pathway involving the activation of leptin receptors (ObRb). We investigated the potential of AMPKα2 in the sympathetic effec...

  10. The Nucleus of the Solitary Tract and the coordination of respiratory and sympathetic activities

    OpenAIRE

    DanielB.Zoccal

    2014-01-01

    It is well known that breathing introduces rhythmical oscillations in the heart rate and arterial pressure levels. Sympathetic oscillations coupled to the respiratory activity have been suggested as an important homeostatic mechanism optimizing tissue perfusion and blood gas uptake/delivery. This respiratory-sympathetic coupling is strengthened in conditions of blood gas challenges (hypoxia and hypercapnia) as a result of the synchronized activation of brainstem respiratory and sympathetic ne...

  11. The nucleus of the solitary tract and the coordination of respiratory and sympathetic activities

    OpenAIRE

    Zoccal, Daniel B.; Furuya, Werner I.; Bassi, Mirian; Colombari, Débora S. A.; Colombari, Eduardo

    2014-01-01

    It is well known that breathing introduces rhythmical oscillations in the heart rate and arterial pressure levels. Sympathetic oscillations coupled to the respiratory activity have been suggested as an important homeostatic mechanism optimizing tissue perfusion and blood gas uptake/delivery. This respiratory-sympathetic coupling is strengthened in conditions of blood gas challenges (hypoxia and hypercapnia) as a result of the synchronized activation of brainstem respiratory and sympathetic ne...

  12. Leptin-Induced Sympathetic Nerve Activation: Signaling Mechanisms and Cardiovascular Consequences in Obesity

    OpenAIRE

    Rahmouni, Kamal

    2010-01-01

    Obesity increases cardiovascular morbidity and mortality in part by inducing hypertension. One factor linking excess fat mass to cardiovascular diseases may be the sympathetic cardiovascular actions of leptin. Initial studies of leptin showed it regulates appetite and enhances energy expenditure by activating sympathetic nerve activity (SNA) to thermogenic brown adipose tissue. Further study, however, demonstrated leptin also causes sympathetic excitation to the kidney that, in turn, increase...

  13. Advantage of recording single-unit muscle sympathetic nerve activity in heart failure

    Directory of Open Access Journals (Sweden)

    HISAYOSHI eMURAI

    2012-05-01

    Full Text Available Elevated sympathetic activation is a characteristic feature of heart failure (HF. Excessive sympathetic activation under resting conditions has been shown to increase from the early stages of the disease, and is related to prognosis. Direct recording of multiunit efferent muscle sympathetic nerve activity (MSNA by microneurography is the best method for quantifying sympathetic nerve activity in humans. To date, this technique has been used to evaluate the actual central sympathetic outflow to the periphery in HF patients at rest and during exercise; however, because the firing occurrence of sympathetic activation is mainly synchronized by pulse pressure, multiunit MSNA, expressed as burst frequency (bursts/min and burst incidence (bursts/100heartbeats, may have limitations for the quantification of sympathetic nerve activity. In HF, multiunit MSNA is near the maximum level, and cannot increase further than the heartbeat. Single-unit MSNA analysis in humans is technically demanding, but provides more detailed information regarding central sympathetic firing. Although a great deal is known about the response of multiunit MSNA to stress, little information is available regarding the responses of single-unit MSNA to physiological stress and disease. The purposes of this review are to describe the differences between multiunit and single-unit MSNA during stress and to discuss the advantages of single-unit MSNA recording in improving our understanding the pathology of increased sympathetic activity in HF.

  14. Clinical usefulness of {sup 123}I-metaiodobenzylguanidine myocardial scintigraphy in diabetic patients with cardiac sympathetic nerve dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Miyanaga, Hajime; Yoneyama, Satoshi; Kamitani, Tadaaki; Kawasaki, Shingo; Takahashi, Toru; Kunishige, Hiroshi [Matsushita Memorial Hospital, Osaka (Japan)

    1995-09-01

    To assess the clinical utility of {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy in evaluating cardiac sympathetic nerve disturbance in diabetic patients, we performed MIBG scintigraphy in 18 diabetic patients and 11 normal controls. Diabetic patients with symptomatic neuropathy (DM2) had a significantly lower heart to mediastinum uptake ratio than did those without neuropathy or normal controls in initial and delayed images (initial image, 1.90{+-}0.27 vs 2.32{+-}0.38, 2.41{+-}0.40, p<0.01; delayed image, 1.80{+-}0.31 vs 2.48{+-}0.35, 2.56{+-}0.28, p<001, respectively). Defect score, assessed visually, were higher in DM2 patients than in patients in the other two groups (initial image, 7{+-}2.6 vs 1.5{+-}1.9, 0.7{+-}0.9; delayed image 10.6{+-}3.3 vs 4.0{+-}2.5, 1.7{+-}1.6 p<0.01, respectively). The maximum washout rate in DM2 patients was also higher than those in patients in the other two groups. The findings of these indices obtained from MIBG scintigraphy coincided with the % low-frequency power extracted from heart rate fluctuations using a power spectral analysis and the results of the Schellong test, which were used to evaluate sympathetic function. These results suggest that MIBG scintigraphy may be useful for evaluating cardiac sympathetic nerve disturbance in patients with diabetes. (author).

  15. Highly sensitive index of sympathetic activity based on time-frequency spectral analysis of electrodermal activity.

    Science.gov (United States)

    Posada-Quintero, Hugo F; Florian, John P; Orjuela-Cañón, Álvaro D; Chon, Ki H

    2016-09-01

    Time-domain indices of electrodermal activity (EDA) have been used as a marker of sympathetic tone. However, they often show high variation between subjects and low consistency, which has precluded their general use as a marker of sympathetic tone. To examine whether power spectral density analysis of EDA can provide more consistent results, we recently performed a variety of sympathetic tone-evoking experiments (43). We found significant increase in the spectral power in the frequency range of 0.045 to 0.25 Hz when sympathetic tone-evoking stimuli were induced. The sympathetic tone assessed by the power spectral density of EDA was found to have lower variation and more sensitivity for certain, but not all, stimuli compared with the time-domain analysis of EDA. We surmise that this lack of sensitivity in certain sympathetic tone-inducing conditions with time-invariant spectral analysis of EDA may lie in its inability to characterize time-varying dynamics of the sympathetic tone. To overcome the disadvantages of time-domain and time-invariant power spectral indices of EDA, we developed a highly sensitive index of sympathetic tone, based on time-frequency analysis of EDA signals. Its efficacy was tested using experiments designed to elicit sympathetic dynamics. Twelve subjects underwent four tests known to elicit sympathetic tone arousal: cold pressor, tilt table, stand test, and the Stroop task. We hypothesize that a more sensitive measure of sympathetic control can be developed using time-varying spectral analysis. Variable frequency complex demodulation, a recently developed technique for time-frequency analysis, was used to obtain spectral amplitudes associated with EDA. We found that the time-varying spectral frequency band 0.08-0.24 Hz was most responsive to stimulation. Spectral power for frequencies higher than 0.24 Hz were determined to be not related to the sympathetic dynamics because they comprised less than 5% of the total power. The mean value of time

  16. Highly sensitive index of sympathetic activity based on time-frequency spectral analysis of electrodermal activity.

    Science.gov (United States)

    Posada-Quintero, Hugo F; Florian, John P; Orjuela-Cañón, Álvaro D; Chon, Ki H

    2016-09-01

    Time-domain indices of electrodermal activity (EDA) have been used as a marker of sympathetic tone. However, they often show high variation between subjects and low consistency, which has precluded their general use as a marker of sympathetic tone. To examine whether power spectral density analysis of EDA can provide more consistent results, we recently performed a variety of sympathetic tone-evoking experiments (43). We found significant increase in the spectral power in the frequency range of 0.045 to 0.25 Hz when sympathetic tone-evoking stimuli were induced. The sympathetic tone assessed by the power spectral density of EDA was found to have lower variation and more sensitivity for certain, but not all, stimuli compared with the time-domain analysis of EDA. We surmise that this lack of sensitivity in certain sympathetic tone-inducing conditions with time-invariant spectral analysis of EDA may lie in its inability to characterize time-varying dynamics of the sympathetic tone. To overcome the disadvantages of time-domain and time-invariant power spectral indices of EDA, we developed a highly sensitive index of sympathetic tone, based on time-frequency analysis of EDA signals. Its efficacy was tested using experiments designed to elicit sympathetic dynamics. Twelve subjects underwent four tests known to elicit sympathetic tone arousal: cold pressor, tilt table, stand test, and the Stroop task. We hypothesize that a more sensitive measure of sympathetic control can be developed using time-varying spectral analysis. Variable frequency complex demodulation, a recently developed technique for time-frequency analysis, was used to obtain spectral amplitudes associated with EDA. We found that the time-varying spectral frequency band 0.08-0.24 Hz was most responsive to stimulation. Spectral power for frequencies higher than 0.24 Hz were determined to be not related to the sympathetic dynamics because they comprised less than 5% of the total power. The mean value of time

  17. Sympathetic system activity in obesity and metabolic syndrome.

    Science.gov (United States)

    Tentolouris, N; Liatis, S; Katsilambros, N

    2006-11-01

    Obesity is a very common disease worldwide, resulting from a disturbance in the energy balance. The metabolic syndrome is also a cluster of abnormalities with basic characteristics being insulin resistance and visceral obesity. The major concerns of obesity and metabolic syndrome are the comorbidities, such as type 2 diabetes, cardiovascular disease, stroke, and certain types of cancers. Sympathetic nervous system (SNS) activity is associated with both energy balance and metabolic syndrome. Sympathomimetic medications decrease food intake, increase resting metabolic rate (RMR), and thermogenic responses, whereas blockage of the SNS exerts opposite effects. The contribution of the SNS to the daily energy expenditure, however, is small ( approximately 5%) in normal subjects consuming a weight maintenance diet. Fasting suppresses, whereas meal ingestion induces SNS activity. Most of the data agree that obesity is characterized by SNS predominance in the basal state and reduced SNS responsiveness after various sympathetic stimuli. Weight loss reduces SNS overactivity in obesity. Metabolic syndrome is characterized by enhanced SNS activity. Most of the indices used for the assessment of its activity are better associated with visceral fat than with total fat mass. Visceral fat is prone to lipolysis: this effect is mediated by catecholamine action on the sensitive beta(3)-adrenoceptors found in the intraabdominal fat. In addition, central fat distribution is associated with disturbances in the hypothalamo-pituitary-adrenal axis, suggesting that a disturbed axis may be implicated in the development of the metabolic syndrome. Furthermore, SNS activity induces a proinflammatory state by IL-6 production, which in turn results in an acute phase response. The increased levels of inflammatory markers seen in the metabolic syndrome may be elicited, at least in part, by SNS overactivity. Intervention studies showed that the disturbances of the autonomic nervous system seen in the

  18. Modeling and imaging cardiac sympathetic neurodegeneration in Parkinson’s disease

    OpenAIRE

    Joers, Valerie; Emborg, Marina E.

    2014-01-01

    Parkinson’s disease (PD) is currently recognized as a multisystem disorder affecting several components of the central and peripheral nervous system. This new understanding of PD helps explain the complexity of the patients’ symptoms while challenges researchers to identify new diagnostic and therapeutic strategies. Cardiac neurodegeneration and dysautonomia affect PD patients and are associated with orthostatic hypotension, fatigue, and abnormal control of electrical heart activity. They can...

  19. [The state of sympathetic-adrenal system in patients with chronic cardiac insufficiency].

    Science.gov (United States)

    Nigmatullin, R R; Kirillova, V V; Dzhordzhikiia, R K; Kudrin, V S; Klodt, P M

    2009-01-01

    Activation of sympato-adrenal system plays an important role in the development of chronic cardiac failure (CCF). However, its relation to morpho-functional state of myocardium in CCF patients is virtually unknown. HPLC with electrochemical detection was used to determine plasma noradrenalin, adrenalin, and their precursors, 3,4-dioxyphenylalanine (DOPA) and dopamine, in patients with different morpho-functional changes in myocardium. The study demonstrated enhanced activity of sympato-adrenal system in patients with CCF. It showed for the first time that activity of sympato-adrenal system in CCF patients depends on the morpho-functional status of myocardium.

  20. Plasma dihydroxyphenylalanine (DOPA) is independent of sympathetic activity in humans

    DEFF Research Database (Denmark)

    Eldrup, E; Christensen, N J; Andreasen, J;

    1989-01-01

    To clarify the origin of plasma DOPA (3,4-Dihydroxyphenylalanine), the relationship between plasma DOPA and acute or chronic changes in sympathetic activity has been studied. Plasma DOPA and noradrenaline (NA) concentrations were measured by reverse-phase high-performance liquid chromatography with...... electrochemical detection. Administration of clonidine to healthy men decreased plasma NE markedly compared to no drug. Plasma DOPA decreased slightly but significantly with time, but values were identical after clonidine compared to no drug. Baseline plasma NE concentrations were significantly reduced in...... diabetic patients with autonomic neuropathy compared to diabetics without neuropathy, whereas baseline plasma DOPA concentrations were similar in the three groups investigated: 6.55 (5.03-7.26, median [interquartile range], n = 8) nmol l-1 in diabetics with neuropathy, 7.41 (5.79-7.97, n = 8) nmol l-1 in...

  1. Effect of weightlessness on sympathetic-adrenomedullary activity of rats

    Science.gov (United States)

    Kvetňanský, R.; Torda, T.; Macho, L.; Tigranian, R. A.; Serova, L.; Genin, A. M.

    Three cosmic experiments were performed in which rats spent 18-20 days in space on board the biosatellites "COSMOS 782", "COSMOS 936" and "COSMOS 1129". The following indicators of the sympathetic-adrenomedullary system (SAS) activity were measured: tissue and plasma catecholamines (CA), CA-synthesizing enzymes—tyrosine hydroxylase (TH), dopamine-β-hydroxylase (DBH), phenylethanolamine-N-methyltransferase (PNMT)—as well as CA-degrading enzymes—monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT). Adrenal epinephrine (EPI) and norepinephrine (NE) as well as CA-synthesizing and degrading enzymes were not significantly changed in the animals after flight on COSMOS 782. On the other hand, a significant increase was found in heart CA, the indicator which is usually decreased after stress. 26 days after landing all values were at control levels. The results obtained, compared to our previous stress experiments on Earth, suggest that prolonged weightlessness does not appear to be a pronounced stressful stimulus for the SAS. Heart and plasma CA, mainly NE, were increased both in the group living in the state of weightlessness and the group living in a centrifuge and exposed to artificial gravitation 1 g (COSMOS 936), suggesting again that prolonged weightlessness is not an intensive stressful stimulus for the SAS. The animals exposed after space flight on COSMOS 1129 to repeated immobilization stress on Earth showed a significant decrease of adrenal EPI and an expressive increase of adrenal TH activity compared to stressed animals which were not in space. Thus, the results corroborate that prolonged state of weightlessness during space flight though not representing by itself an intensive stressful stimulus for the sympathetic-adrenomedullary system, was found to potentiate the response of "cosmic rats" to stress exposure after return to Earth.

  2. Involvement of hypothalamic AMP-activated protein kinase in leptin-induced sympathetic nerve activation.

    Directory of Open Access Journals (Sweden)

    Mamoru Tanida

    Full Text Available In mammals, leptin released from the white adipose tissue acts on the central nervous system to control feeding behavior, cardiovascular function, and energy metabolism. Central leptin activates sympathetic nerves that innervate the kidney, adipose tissue, and some abdominal organs in rats. AMP-activated protein kinase (AMPK is essential in the intracellular signaling pathway involving the activation of leptin receptors (ObRb. We investigated the potential of AMPKα2 in the sympathetic effects of leptin using in vivo siRNA injection to knockdown AMPKα2 in rats, to produce reduced hypothalamic AMPKα2 expression. Leptin effects on body weight, food intake, and blood FFA levels were eliminated in AMPKα2 siRNA-treated rats. Leptin-evoked enhancements of the sympathetic nerve outflows to the kidney, brown and white adipose tissues were attenuated in AMPKα2 siRNA-treated rats. To check whether AMPKα2 was specific to sympathetic changes induced by leptin, we examined the effects of injecting MT-II, a melanocortin-3 and -4 receptor agonist, on the sympathetic nerve outflows to the kidney and adipose tissue. MT-II-induced sympatho-excitation in the kidney was unchanged in AMPKα2 siRNA-treated rats. However, responses of neural activities involving adipose tissue to MT-II were attenuated in AMPKα2 siRNA-treated rats. These results suggest that hypothalamic AMPKα2 is involved not only in appetite and body weight regulation but also in the regulation of sympathetic nerve discharges to the kidney and adipose tissue. Thus, AMPK might function not only as an energy sensor, but as a key molecule in the cardiovascular, thermogenic, and lipolytic effects of leptin through the sympathetic nervous system.

  3. Comparison of sympathetic nerve activity normalization procedures in conscious rabbits.

    Science.gov (United States)

    Burke, Sandra L; Lim, Kyungjoon; Moretti, John-Luis; Head, Geoffrey A

    2016-05-01

    One of the main constraints associated with recording sympathetic nerve activity (SNA) in both humans and experimental animals is that microvolt values reflect characteristics of the recording conditions and limit comparisons between different experimental groups. The nasopharyngeal response has been validated for normalizing renal SNA (RSNA) in conscious rabbits, and in humans muscle SNA is normalized to the maximum burst in the resting period. We compared these two methods of normalization to determine whether either could detect elevated RSNA in hypertensive rabbits compared with normotensive controls. We also tested whether either method eliminated differences based only on different recording conditions by separating RSNA of control (sham) rabbits into two groups with low or high microvolts. Hypertension was induced by 5 wk of renal clipping (2K1C), 3 wk of high-fat diet (HFD), or 3 mo infusion of a low dose of angiotensin (ANG II). Normalization to the nasopharyngeal response revealed RSNA that was 88, 51, and 34% greater in 2K1C, HFD, and ANG II rabbits, respectively, than shams (P < 0.05), but normalization to the maximum burst showed no differences. The RSNA baroreflex followed a similar pattern whether RSNA was expressed in microvolts or normalized. Both methods abolished the difference between low and high microvolt RSNA. These results suggest that maximum burst amplitude is a useful technique for minimizing differences between recording conditions but is unable to detect real differences between groups. We conclude that the nasopharyngeal reflex is the superior method for normalizing sympathetic recordings in conscious rabbits. PMID:26921439

  4. Significance of cardiac sympathetic nervous system abnormality for predicting vascular events in patients with idiopathic paroxysmal atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Akutsu, Yasushi; Kaneko, Kyouichi; Kodama, Yusuke; Li, Hui-Ling; Kawamura, Mitsuharu; Asano, Taku; Hamazaki, Yuji; Tanno, Kaoru; Kobayashi, Youichi [Showa University School of Medicine, Division of Cardiology, Department of Medicine, Tokyo (Japan); Suyama, Jumpei; Shinozuka, Akira; Gokan, Takehiko [Showa University School of Medicine, Department of Radiology, Tokyo (Japan)

    2010-04-15

    Neuronal system activity plays an important role for the prognosis of patients with atrial fibrillation (AF). Using {sup 123}I metaiodobenzylguanidine ({sup 123}I-MIBG) scintigraphy, we investigated whether a cardiac sympathetic nervous system (SNS) abnormality would be associated with an increased risk of vascular events in patients with paroxysmal AF. {sup 123}I-MIBG scintigraphy was performed in 69 consecutive patients (67 {+-} 13 years, 62% men) with paroxysmal AF who did not have structural heart disease. SNS integrity was assessed from the heart to mediastinum (H/M) ratio on delayed imaging. Serum concentration of C-reactive protein (CRP) was measured before {sup 123}I-MIBG study. During a mean of 4.5 {+-} 3.6 years follow-up, 19 patients had myocardial infarction, stroke or heart failure (range: 0.2-11.5 years). SNS abnormality (H/M ratio <2.7) and high CRP ({>=}0.3 mg/dl) were associated with the vascular events (58.3% in 14 of 24 patients with SNS abnormality vs 11.1% in 5 of 45 patients without SNS abnormality, p < 0.0001, 52.4% in 11 of 21 patients with high CRP vs 16.7% in 8 of 48 patients without high CRP, p < 0.0001). After adjustment for potential confounding variables such as age, left atrial dimension and left ventricular function, SNS abnormality was an independent predictor of vascular events with a hazard ratio of 4.1 [95% confidence interval (CI): 1.3-12.6, p = 0.014]. Further, SNS abnormality had an incremental and additive prognostic power in combination with high CRP with an adjusted hazard ratio of 4.1 (95% CI: 1.5-10.9, p = 0.006). SNS abnormality is predictive of vascular events in patients with idiopathic paroxysmal AF. (orig.)

  5. Significance of cardiac sympathetic nervous system abnormality for predicting vascular events in patients with idiopathic paroxysmal atrial fibrillation

    International Nuclear Information System (INIS)

    Neuronal system activity plays an important role for the prognosis of patients with atrial fibrillation (AF). Using 123I metaiodobenzylguanidine (123I-MIBG) scintigraphy, we investigated whether a cardiac sympathetic nervous system (SNS) abnormality would be associated with an increased risk of vascular events in patients with paroxysmal AF. 123I-MIBG scintigraphy was performed in 69 consecutive patients (67 ± 13 years, 62% men) with paroxysmal AF who did not have structural heart disease. SNS integrity was assessed from the heart to mediastinum (H/M) ratio on delayed imaging. Serum concentration of C-reactive protein (CRP) was measured before 123I-MIBG study. During a mean of 4.5 ± 3.6 years follow-up, 19 patients had myocardial infarction, stroke or heart failure (range: 0.2-11.5 years). SNS abnormality (H/M ratio <2.7) and high CRP (≥0.3 mg/dl) were associated with the vascular events (58.3% in 14 of 24 patients with SNS abnormality vs 11.1% in 5 of 45 patients without SNS abnormality, p < 0.0001, 52.4% in 11 of 21 patients with high CRP vs 16.7% in 8 of 48 patients without high CRP, p < 0.0001). After adjustment for potential confounding variables such as age, left atrial dimension and left ventricular function, SNS abnormality was an independent predictor of vascular events with a hazard ratio of 4.1 [95% confidence interval (CI): 1.3-12.6, p = 0.014]. Further, SNS abnormality had an incremental and additive prognostic power in combination with high CRP with an adjusted hazard ratio of 4.1 (95% CI: 1.5-10.9, p = 0.006). SNS abnormality is predictive of vascular events in patients with idiopathic paroxysmal AF. (orig.)

  6. Respiratory modulation of sympathetic nerve activity is enhanced in male rat offspring following uteroplacental insufficiency.

    Science.gov (United States)

    Menuet, C; Wlodek, M E; Fong, A Y; Allen, A M

    2016-06-01

    Sympathetic nerve activity to the cardiovascular system displays prominent respiratory-related modulation which leads to the generation of rhythmic oscillations in blood pressure called Traube-Hering waves. An amplification of this respiratory modulation of sympathetic activity is observed in hypertension of both genetic, the spontaneously hypertensive rat, and induced, chronic intermittent hypoxia or maternal protein restriction during gestation, origin. Male offspring of mothers with uteroplacental insufficiency, induced by bilateral uterine vessel ligation at 18 days of gestation, are also hypertensive in adulthood. In this study we examined whether these male offspring display altered respiratory modulation of sympathetic activity at pre-hypertensive ages compared to controls. Respiratory, cardiovascular and sympathetic parameters were examined using the working heart-brainstem preparation in 35 day old male rats that had reduced birth weight due to uteroplacental insufficiency. Whilst all respiratory parameters were not different between groups, we observed an enhanced respiratory-related burst of thoracic sympathetic nerve activity and amplified Traube-Hering waves in the growth-restricted group. This group also showed an increased sympathetic and bradycardic response to activation of peripheral chemoreceptors. The observations add support to the view that altered respiratory modulation of sympathetic activity represents a common mechanism involved in the development of several forms of hypertension. PMID:26593642

  7. Sympathetic reinnervation in cardiac transplants: 123I-MIBG and 201Tl/99mTc-MIBI scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. H.; Oh, S. J.; Son, M. S.; Son, J. W.; Koh, K. K.; Choi, I. S.; Shin, E. K.; Park, K. Y. [Gachon Medical College, Gil Heart Center, Inchon (Korea, Republic of)

    1998-07-01

    Iodine-123 metaiodobenzylguanidine (123I-MIBG) is a norepinephrine (NE) analogue and taken up by myocardial sympathetic nerves. To determine whether cardiac sympathetic reinnervation occurs after orthotopic heart transplantation (TPL). We performed 24 serial or followup cardiac 123I-MIBG imaging and 201T1/99mTc-MIBI dipyridamole stress gated myocardial perfusion SPECT (g-MPS) in 15 pts(M : F =10 : 5; mean ages = 34.67{+-}12.92 yr; idiopathic: rheumatic=14:1) (10.80{+-}11.88 (1-48) mo) after TPL. 123I-MIBG imagins were performed in anterior position 15 minutes, 4 and 24 hours after i.v. injection of 148 MBq 123I MIBG. Image quantitation was based on the ratio of heart to mediastinal MIBG uptake (HMR). 12 subjects with < 13 (4.91{+-}3.67) months after TPL had no visible 123I-MIBG uptake on early 15 min imaging however, 12 subjects with 13 to 48(28.58{+-}12.77) months had visible cardiac 123I-MIBG uptake (HMR: 1.65 {+-}0.21 vs. 1.32{+-}0.26 p=0.002). Correlation was found between plasma NE concentration and HMR ( r=0.80: p<0.05). Compared to HMR on 15 min images (1.48{+-}0.28), neither four nor 24 hour delayed images (1.26{+-}0.23 vs. 1.06{+-}0.10 : p<0.05, respectively, ANOVA) showed definite delayed localization of MIBG. To dipyridamole stress, transplant hearts showed significant subnormal hemodynamic responses of HR, s-BP, d-BP, and rate pressure product (90.9{+-}14.9 to 102.2{+-}15.3, 136.5{+-}17.3 to 124.9{+-}13.3, 83.3{+-}12.5 to 74.7{+-}15.6, 123.2{+-}19.4 to 127.4{+-}21.8 p<0.05, respectively). One-year followup 123I-MIBG scintigraphy in nine pts showed increased HMR (1.50{+-}0,37 to 1.61{+-}0.15, p=ns) but couldnt reach the statistical significance. Out of nine followup patients, five showed increased HMR but four didnt. gMPS performed at post-TPL 48 months in one patient complaining vague chest pain whose HMR value 1.73 to 1.62 showed an apicoanterior wall reversible perfusion defect which confirmed as 90% distal left anterior descending artery stenosis by

  8. {sup 123}I-Labelled metaiodobenzylguanidine for the evaluation of cardiac sympathetic denervation in early stage amyloidosis

    Energy Technology Data Exchange (ETDEWEB)

    Noordzij, Walter; Glaudemans, Andor W.J.M.; Rheenen, Ronald W.J. van; Dierckx, Rudi A.J.O.; Slart, Riemer H.J.A. [University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, PO Box 30.001, Groningen (Netherlands); Hazenberg, Bouke P.C. [University of Groningen, Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Groningen (Netherlands); Tio, Rene A. [University of Groningen, Department of Cardiology, University Medical Center Groningen, Groningen (Netherlands)

    2012-10-15

    Cardiac amyloidosis is a rare disorder, but it may lead to potentially life-threatening restrictive cardiomyopathy. Cardiac manifestations frequently occur in primary amyloidosis (AL) and familial amyloidosis (ATTR), but are uncommon in secondary amyloidosis (AA). Echocardiography is the method of choice for assessing cardiac amyloidosis. Amyloid deposits impair the function of sympathetic nerve endings. Disturbance of myocardial sympathetic innervations may play an important role in the remodelling process. {sup 123}I-MIBG can detect these innervation changes. Patients with biopsy-proven amyloidosis underwent general work-up, echocardiography and {sup 123}I-MIBG scintigraphy. Left ventricular internal dimensions and wall thickness were measured, and highly refractile cardiac echoes (sparkling) were analysed. Early (15 min) and late (4 h) heart-to-mediastinum ratio (HMR) and wash-out rate were determined after administration of MIBG. Included in the study were 61 patients (30 women and 31 men; mean age 62 years; 39 AL, 11 AA, 11 ATTR). Echocardiographic parameters were not significantly different between the groups. Sparkling was present in 72 % of ATTR patients, in 54 % of AL patients and in 45 % of AA patients. Mean late HMR in all patients was 2.3 {+-} 0.75, and the mean wash-out rate was 8.6 {+-} 14 % (the latter not significantly different between the patient groups). Late HMR was significantly lower in patients with echocardiographic signs of amyloidosis than in patients without (2.0 {+-} 0.70 versus 2.8 {+-} 0.58, p < 0.001). Wash-out rates were significantly higher in these patients (-3.3 {+-} 9.9 % vs. 17 {+-} 10 %, p < 0.001). In ATTR patients without echocardiographic signs of amyloidosis, HMR was lower than in patients with the other types (2.0 {+-} 0.59 vs. 2.9 {+-} 0.50, p = 0.007). MIBG HMR is lower and wash-out rate is higher in patients with echocardiographic signs of amyloidosis. Also, {sup 123}I-MIBG scintigraphy can detect cardiac denervation in

  9. The role of carotid chemoreceptors in the sympathetic activation by adenosine in humans.

    NARCIS (Netherlands)

    Timmers, H.J.L.M.; Rongen, G.A.P.J.M.; Karemaker, J.M.; Wieling, W.; Marres, H.A.M.; Lenders, J.W.M.

    2004-01-01

    The direct vasodilatory and negative chronotropic effects of adenosine in humans are counterbalanced by a reflex increase in sympathetic nerve traffic. A suggested mechanism for this reflex includes peripheral chemoreceptor activation. We, therefore, assessed the contribution of carotid chemorecepto

  10. The Nucleus of the Solitary Tract and the coordination of respiratory and sympathetic activities

    Directory of Open Access Journals (Sweden)

    Daniel B. Zoccal

    2014-06-01

    Full Text Available It is well known that breathing introduces rhythmical oscillations in the heart rate and arterial pressure levels. Sympathetic oscillations coupled to the respiratory activity have been suggested as an important homeostatic mechanism optimizing tissue perfusion and blood gas uptake/delivery. This respiratory-sympathetic coupling is strengthened in conditions of blood gas challenges (hypoxia and hypercapnia as a result of the synchronized activation of brainstem respiratory and sympathetic neurons, culminating with the emergence of entrained cardiovascular and respiratory reflex responses. Studies have proposed that the ventrolateral region of the medulla oblongata is a major site of synaptic interaction between respiratory and sympathetic neurons. However, other brainstem regions also play a relevant role in the patterning of respiratory and sympathetic motor outputs. Recent findings suggest that the neurons of the nucleus of the solitary tract (NTS, in the dorsal medulla, are essential for the processing and coordination of respiratory and sympathetic responses to hypoxia. The NTS is the first synaptic station of the cardiorespiratory afferent inputs, including peripheral chemoreceptors, baroreceptors and pulmonary stretch receptors. The synaptic profile of the NTS neurons receiving the excitatory drive from afferent inputs is complex and involves distinct neurotransmitters, including glutamate, ATP and acetylcholine. In the present review we discuss the role of the NTS circuitry in coordinating sympathetic and respiratory reflex responses. We also analyze the neuroplasticity of NTS neurons and their contribution for the development of cardiorespiratory dysfunctions, as observed in neurogenic hypertension, obstructive sleep apnea and metabolic disorders.

  11. LMI1195 PET imaging in evaluation of regional cardiac sympathetic denervation and its potential role in antiarrhythmic drug treatment

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ming; Bozek, Jody; Lamoy, Melanie; Kagan, Mikhail; Benites, Pedro; Onthank, David; Robinson, Simon P. [Lantheus Medical Imaging, Discovery Research, N. Billerica, MA (United States)

    2012-12-15

    Regional cardiac sympathetic denervation (RCSD) associated with reduced noradrenaline transporter (NAT) function has been linked to cardiac arrhythmia. This study examined the association of LMI1195, an {sup 18}F-labeled NAT substrate developed for positron emission tomography (PET) imaging, with NAT in vitro, and its imaging to detect RCSD and guide antiarrhythmic drug treatment in vivo. LMI1195 association with NAT was assessed in comparison with other substrates, noradrenaline (NA) and {sup 123}I-metaiodobenzylguanidine (MIBG), in NAT-expressing cells. LMI1195 cardiac imaging was performed for evaluation of RCSD in a rabbit model surgically developed by regional phenol application on the left ventricular (LV) wall. The normal LV areas in images were quantified as regions with radioactivity {>=}50 % maximum. Potential impact of RCSD on dofetilide, an antiarrhythmic drug, induced ECG changes was assessed. NAT blockade with desipramine reduced LMI1195 cell uptake by 90 {+-} 3 %, similar to NA and MIBG. NA, MIBG, or self inhibited LMI1195 cell uptake concentration-dependently with comparable IC{sub 50} values (1.09, 0.21, and 0.90 {mu}M). LMI1195 cardiac imaging differentiated innervated and denervated areas in RCSD rabbits. The surgery resulted in a large denervated LV area at 2 weeks which was partially recovered at 12 weeks. Myocardial perfusion imaging with flurpiridaz F 18 showed normal perfusion in RCSD areas. Dofetilide induced more prominent QTc prolongation in RCSD than control animals. However, changes in heart rate were comparable. LMI1195 exhibits high association with NAT and can be used for imaging RCSD. The detected RCSD increases cardiac risks to the antiarrhythmic drug, dofetilide, by inducing more QTc prolongation. (orig.)

  12. Enhanced adipose afferent reflex contributes to sympathetic activation in diet-induced obesity hypertension.

    Science.gov (United States)

    Xiong, Xiao-Qing; Chen, Wei-Wei; Han, Ying; Zhou, Ye-Bo; Zhang, Feng; Gao, Xing-Ya; Zhu, Guo-Qing

    2012-11-01

    We recently found that adipose afferent reflex (AAR) induced by chemical stimulation of white adipose tissue (WAT) increased sympathetic outflow and blood pressure in normal rats. The study was designed to test the hypothesis that AAR contributes to sympathetic activation in obesity hypertension. Male rats were fed with a control diet (12% kcal as fat) or high-fat diet (42% kcal as fat) for 12 weeks to induce obesity hypertension. Stimulation of WAT with capsaicin increased renal sympathetic nerve activity and mean arterial pressure. Both AAR and WAT afferent activity were enhanced in obesity hypertension (OH) compared with obesity nonhypertension (ON) and in ON compared with obesity-resistant or control diet rats. WAT sensory denervation induced by resiniferatoxin caused greater decreases in renal sympathetic nerve activity and mean arterial pressure in OH than ON and in ON than obesity-resistant or control. The depressor effect of resiniferatoxin lasted ≥ 3 weeks in OH. Leptin antagonist in WAT reduced renal sympathetic nerve activity and mean arterial pressure in OH. WAT injection of capsaicin increased plasma renin, angiotensin II, and norepinephrine levels in OH and caused more c-fos expression in paraventricular nucleus in OH than ON and in ON than obesity-resistant or control rats. Inhibiting paraventricular nucleus neurons with lidocaine attenuated renal sympathetic nerve activity in OH and ON, decreased mean arterial pressure in OH, and abolished the capsaicin-induced AAR in all groups. The results indicate that enhanced AAR contributes to sympathetic activation in OH, and paraventricular nucleus plays an important role in the enhanced AAR and sympathetic activation in OH.

  13. Effects of alpha-adrenoceptor and of combined sympathetic and parasympathetic blockade on cardiac performance and vascular resistance

    DEFF Research Database (Denmark)

    Kelbaek, H; Frandsen, Henrik Lund; Hilsted, J;

    1992-01-01

    ) blockade. 2. During alpha-adrenoceptor blockade heart rate and cardiac output increased considerably and left ventricular ejection fraction increased because of increased contractility. Systemic vascular resistance fell both during alpha-adrenoceptor blockade alone and during combined blockade. The...... increase in calf blood flow was of the same magnitude after combined blockade and after alpha-adrenoceptor blockade alone, and was considerably higher than the fall in systemic vascular resistance. Plasma catecholamine concentrations increased after phentolamine, but the changes were blunted when...... propranolol and atropine were added. 3. These results indicate that peripheral vasoconstriction especially that exerted by alpha-adrenoceptor nervous tone in skeletal muscle restricts left ventricular emptying of the intact heart. During pharmacologic blockade of the sympathetic and parasympathetic nervous...

  14. LEPTIN SIGNALING IN THE NUCLEUS TRACTUS SOLITARII INCREASES SYMPATHETIC NERVE ACTIVITY TO THE KIDNEY

    OpenAIRE

    Mark, Allyn L.; Agassandian, Khristofor; Morgan, Donald A.; Liu, Xuebo; Cassell, Martin D.; Rahmouni, Kamal

    2008-01-01

    The hypothalamic arcuate nucleus was initially regarded as the principal site of leptin action, but there is increasing evidence for functional leptin receptors (Ob-Rb) in extra-hypothalamic sites, including the nucleus tractus solitarii (NTS). We previously demonstrated that arcuate injection of leptin increases sympathetic nerve activity (SNA) to brown adipose tissue (BAT) and kidney. In this study, we tested the hypothesis that leptin signaling in the NTS affects sympathetic neural outflow...

  15. Leptin‐Induced Endothelial Dysfunction Is Mediated by Sympathetic Nervous System Activity

    OpenAIRE

    Wang, Jintao; Wang, Hui; Luo, Wei; Guo, Chiao; Wang, Julia; Chen, Y.E.; Chang, Lin; Eitzman, Daniel T.

    2013-01-01

    Background The adipocyte‐derived hormone leptin is elevated in obesity and may contribute to vascular risk associated with obesity. The mechanism(s) by which leptin affects vascular disease is unclear, although leptin has been shown to increase sympathetic activity. The aim of this study was to investigate the effect of leptin treatment on endothelial function and the role of the local sympathetic nervous system in mediating these effects. Methods and Results Recombinant leptin was administer...

  16. Leptin into the rostral ventral lateral medulla (RVLM augments renal sympathetic nerve activity and blood pressure

    Directory of Open Access Journals (Sweden)

    Maria J Barnes

    2014-08-01

    Full Text Available Leptin is a hormone released from adipose tissue. While this hormone normally acts to reduce feeding behavior and increase energy expenditure, in obesity, resistance to these effects occurs even though the hormone is released in large amounts. Although leptin no longer works to suppress feeding in the obese, leptin retains its potent effects on other autonomic functions such as blood pressure regulation. Leptin has been associated with hypertension and increased sympathetic autonomic activity. Therefore, leptin is emerging as a major contributor to the hypertensive state observed in obesity. Sympathetic control of blood pressure is maintained principally by autonomic reflex control circuits in the caudal brainstem. The rostral ventral-lateral medulla (RVLM is the primary regulator of the sympathetic nervous system, sending excitatory fibers to sympathetic preganglionic neurons to regulate sympathetic control over resistance vessels and blood pressure. Previous studies from our laboratory have shown that neurons in the ventral lateral medulla express leptin receptors (ObRb. Our present study using pseudo-rabies multi-synaptic retrograde tract tracing and immunohistochemical methods revealed that neurons within the RVLM that send sympathetic projections to the kidney express leptin receptors. Acute microinjection of leptin (1 and 3µg; 40nL into the RVLM evoked a significant increase in Mean Arterial Pressure (MAP and renal sympathetic nerve activity (RSNA. When the 3µg dose of leptin was preceded with a leptin antagonist, (SLAN-4; 1ng, it attenuated the cardiovascular response of leptin. Taken together, these data suggest that leptin’s actions within the RVLM may influence blood pressure and renal sympathetic nerve activity.

  17. Using Lorenz plot and Cardiac Sympathetic Index of heart rate variability for detecting seizures for patients with epilepsy.

    Science.gov (United States)

    Jeppesen, Jesper; Beniczky, Sandor; Johansen, Peter; Sidenius, Per; Fuglsang-Frederiksen, Anders

    2014-01-01

    Tachycardia is often seen during epileptic seizures, but it also occurs during physical exercise. In order to assess whether focal epileptic seizures can be detected by short term moving window Heart Rate Variability (HRV) analysis, we modified the geometric HRV method, Lorenz plot, to consist of only 30, 50 or 100 R-R intervals per analyzed window. From each window we calculated the longitudinal (L) and transverse (T) variability of Lorenz plot to retrieve the Cardiac Sympathetic Index (CSI) as (L/T) and "Modified CSI" (described in methods), and compared the maximum during the patient's epileptic seizures with that during the patient's own exercise and non-seizure sessions as control. All five analyzed patients had complex partial seizures (CPS) originating in the temporal lobe (11 seizures) during their 1-5 days long term video-EEG monitoring. All CPS with electroencephalographic correlation were selected for the HRV analysis. The CSI and Modified CSI were correspondently calculated after each heart beat depicting the prior 30, 50 and 100 R-R intervals at the time. CSI (30, 50 and 100) and Modified CSI (100) showed a higher maximum peak during seizures than exercise/non-seizure (121-296%) for 4 of the 5 patients within 4 seconds before till 60 seconds after seizure onset time even though exercise maximum HR exceeded that of the seizures. The results indicate a detectable, sudden and inordinate shift towards sympathetic overdrive in the sympathovagal balance of the autonomic nervous system just around seizure-onset for certain patients. This new modified moving window Lorenz plot method seems promising way of constructing a portable ECG-based epilepsy alarm for certain patients with epilepsy who needs aid during seizure.

  18. Regional heterogeneity in cardiac sympathetic innervation in acute myocardial infarction: relationship with myocardial oedema on magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Gimelli, Alessia; Masci, Pier Giorgio; Pasanisi, Emilio Maria; Lombardi, Massimo [Fondazione CNR/Regione Toscana, Pisa (Italy); Liga, Riccardo; Grigoratos, Chrysanthos [University Hospital of Pisa, Pisa (Italy); Marzullo, Paolo [Fondazione CNR/Regione Toscana, Pisa (Italy); Institute of Clinical Physiology, CNR, Pisa (Italy)

    2014-09-15

    To assess the relationships between myocardial structure and function on cardiac magnetic resonance (CMR) imaging and sympathetic tone on {sup 123}I-metaiodobenzylguanidine ({sup 123}I-MIBG) scintigraphy early after myocardial infarction (MI). Ten patients underwent {sup 123}I-MIBG and {sup 99m}Tc-tetrofosmin rest cadmium zinc telluride scintigraphy 4 ± 1 days after MI. The segmental left ventricular (LV) relative radiotracer uptake of both {sup 99m}Tc-tetrofosmin and early {sup 123}I-MIBG was calculated. The day after scintigraphy, on CMR imaging, the extent of ischaemia-related oedema and of myocardial fibrosis (late gadolinium enhancement, LGE) was assessed. Accordingly, the extent of oedema and LGE was evaluated for each segment and segmental wall thickening determined. Based on LGE distribution, LV segments were categorized as ''infarcted'' (56 segments), ''adjacent'' (66 segments) or ''remote'' (48 segments). Infarcted segments showed a more depressed systolic wall thickening and greater extent of oedema than adjacent segments (p < 0.001) and remote segments (p < 0.001). Interestingly, while uptake of {sup 99m}Tc-tetrofosmin was significantly depressed only in infarcted segments (p < 0.001 vs. both adjacent and remote segments), uptake of {sup 123}I-MIBG was impaired not only in infarcted segments (p < 0.001 vs. remote) but also in adjacent segments (p = 0.024 vs. remote segments). At the regional level, after correction for {sup 99m}Tc-tetrofosmin and LGE distribution, segmental {sup 123}I-MIBG uptake (p < 0.001) remained an independent predictor of ischaemia-related oedema. After acute MI the regional impairment of sympathetic tone extends beyond the area of altered myocardial perfusion and is associated with myocardial oedema. (orig.)

  19. Nicotine and sympathetic neurotransmission.

    Science.gov (United States)

    Haass, M; Kübler, W

    1997-01-01

    Nicotine increases heart rate, myocardial contractility, and blood pressure. These nicotine-induced cardiovascular effects are mainly due to stimulation of sympathetic neurotransmission, as nicotine stimulates catecholamine release by an activation of nicotine acetylcholine receptors localized on peripheral postganglionic sympathetic nerve endings and the adrenal medulla. The nicotinic acetylcholine receptor is a ligand-gated cation channel with a pentameric structure and a central pore with a cation gate, which is essential for ion selectivity and permeability. Binding of nicotine to its extracellular binding site leads to a conformational change of the central pore, which results in the influx of sodium and calcium ions. The resulting depolarization of the sympathetic nerve ending stimulates calcium influx through voltage-dependent N-type calcium channels, which triggers the nicotine-evoked exocytotic catecholamine release. In the isolated perfused guinea-pig heart, cardiac energy depletion sensitizes cardiac sympathetic nerves to the norepinephrine-releasing effect of nicotine, as indicated by a leftward shift of the concentration-response curve, a potentiation of maximum transmitter release, and a delay of the tachyphylaxis of nicotine-evoked catecholamine release. This sensitization was also shown to occur in the human heart under in vitro conditions. Through the intracardiac release of norepinephrine, nicotine induces a beta-adrenoceptor-mediated increase in heart rate and contractility, and an alpha-adrenoceptor-mediated increase in coronary vasomotor tone. The resulting simultaneous increase in oxygen demand and coronary resistance has a detrimental effect on the oxygen balance of the heart, especially in patients with coronary artery disease. Sensitization of the ischemic heart to the norepinephrine-releasing effect of nicotine may be a trigger for acute cardiovascular events in humans, such as acute myocardial infarction and/or life

  20. Neurophysiological assessment of sympathetic cardiovascular activity after loss of postganglionic neurons in the anesthetized rat.

    Science.gov (United States)

    Zahner, Matthew R; Liu, Chang-Ning; Okerberg, Carlin V; Opsahl, Alan C; Bobrowski, Walter F; Somps, Chris J

    2016-01-01

    The goal of this study was to determine the degree of sympathetic postganglionic neuronal loss required to impair cardiovascular-related sympathetic activity. To produce neuronal loss separate groups of rats were treated daily with guanethidine for either 5days or 11days, followed by a recovery period. Sympathetic activity was measured by renal sympathetic nerve activity (RSNA). Stereology of thoracic (T13) ganglia was performed to determine neuronal loss. Despite loss of more than two thirds of neurons in T13 ganglia in both treated groups no effect on resting blood pressure (BP) or heart rate (HR) was detected. Basal RSNA in rats treated for 5days (0.61±0.10μV∗s) and 11days (0.37±0.08μV∗s) was significantly less than vehicle-treated rats (0.99±0.13μV∗s, preflex sympathetic responsiveness rather than basal activity alone must be assessed for complete detection of neurophysiological cardiovascular impairment. PMID:27085835

  1. EFFECTS OF INTRAVENOUS FENTANYL ON SPONTANEOUS RENAL SYMPATHETIC NERVE ACTIVITY IN NORMAL AND VAGOTOMIZED RABBITS

    Institute of Scientific and Technical Information of China (English)

    Chen Wang; James G.Whitwam

    2004-01-01

    Objective To investigate the roles of sympathetic and vagus nerves in hypotension and bradycardia induced by fentanyl.Methods Fourteen rabbits were divided into 2 groups: normal and vagotomized rabbits. Rabbits were anesthetized,paralyzed, and artificial ventilated. Right renal sympathetic nerve was exposed and prepared for recording electrical activity.Fentanyl was injected intravenously in incremental doses of 1, 4, 15, 30, and 50 μg/kg at 10 minutes intervals.Results Fentanyl significantly reduced the spontaneous activity of renal sympathetic nerve, mean arterial pressure, and heart rate above a total dose of 20 μg/kg in both normal and vagotomized rabbits. However, normal rabbits spontaneous sympathetic nerve activity and mean arterial pressure were more depressed than vagotomized rabbits at total doses of 50 and 100 μg/kg. There were no significant difference in the reduction of heart rate between normal and vagotomized rabbits.Conclusion Fentanyl induction of bradycardia and hypotension in rabbits is mainly due to depression of sympathetic nerve activity.

  2. A case of cardiac sudden death related to abnormality of sympathetic nervous disturbance detected by {sup 123}I-metaiodobenzylguanidine (MIBG)

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, Masaki; Matsukawa, Seishirou; Morishita, Takeshi [Toho Univ., Tokyo (Japan). School of Medicine

    1996-11-01

    A case of cardiac sudden death was reported. A female, 64 years old patient with multiple myeloma had been treated with total dose of 790 mg of adriamycin. Although treadmill examination, dobutamine-loaded cardiac echography and thallium-loaded myocardial scintigraphy gave normal findings, Holter ECG revealed bigeminy and discontinuous ventricular tachycardia. Mexiletine was not tolerated. {sup 123}I-MIBG image gave deficit of lateral to posterior wall and increased washing rate of 65%. At 36 days after hospitalization, the ventricular tachycardia changed to fatal fibrillation. The sympathetic nervous disturbance detected by the enhanced washing rate of {sup 123}I-MIBG might have participated in the death. (K.H.)

  3. Marital Conflict and Children's Externalizing Behavior: Interactions between Parasympathetic and Sympathetic Nervous System Activity

    Science.gov (United States)

    El-Sheikh, Mona; Kouros, Chrystyna D.; Erath, Stephen; Cummings, E. Mark; Keller, Peggy; Staton, Lori

    2009-01-01

    Toward greater specificity in the prediction of externalizing problems in the context of interparental conflict, interactions between children's parasympathetic and sympathetic nervous system (PNS and SNS) activity were examined as moderators. PNS activity was indexed by respiratory sinus arrhythmia (RSA) and RSA reactivity (RSA-R) to lab…

  4. Evaluation of cardiac sympathetic neuronal integrity in diabetic patients using iodine-123 metaiodobenzylguanidine

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Jung [Department of Diagnostic Radiology and Nuclear Medicine, Yonsei University, College of Medicine, 134 Shincheon-dong, Seodaemun-gu, Seoul, 120-752 (Korea, Republic of); Lee, Jong Doo [Department of Diagnostic Radiology and Nuclear Medicine, Yonsei University, College of Medicine, 134 Shincheon-dong, Seodaemun-gu, Seoul, 120-752 (Korea, Republic of); Ryu, Young Hoon [Department of Diagnostic Radiology and Nuclear Medicine, Yonsei University, College of Medicine, 134 Shincheon-dong, Seodaemun-gu, Seoul, 120-752 (Korea, Republic of); Jeon, Pyoung [Department of Diagnostic Radiology and Nuclear Medicine, Yonsei University, College of Medicine, 134 Shincheon-dong, Seodaemun-gu, Seoul, 120-752 (Korea, Republic of); Shim, Yong Woon [Department of Diagnostic Radiology and Nuclear Medicine, Yonsei University, College of Medicine, 134 Shincheon-dong, Seodaemun-gu, Seoul, 120-752 (Korea, Republic of); Yoo, Hyung Sik [Department of Diagnostic Radiology and Nuclear Medicine, Yonsei University, College of Medicine, 134 Shincheon-dong, Seodaemun-gu, Seoul, 120-752 (Korea, Republic of); Park, Chang Yun [Department of Diagnostic Radiology and Nuclear Medicine, Yonsei University, College of Medicine, 134 Shincheon-dong, Seodaemun-gu, Seoul, 120-752 (Korea, Republic of); Lim, Seung Gil [Department of Endocrinology, Yonsei University, College of Medicine, 134 Shincheon-dong, Seodaemun-gu, Seoul, 120-752 (Korea, Republic of)

    1996-04-01

    Autonomic dysfunction is associated with increased mortality in diabetic patients. To evaluate the cardiac autonomic dysfunction in these patients, a prospective study was undertaken using iodine-123 metaiodobenzylguanidine (MIBG) single-photon emission tomography (SPET). The study groups consisted of ten diabetic patients with cardiac autonomic neuropathy (group I) and six without autonomic neuropathy (group II). Autonomic nervous function tests, thallium scan, radionuclide ventriculographic data including ejection fraction and wall motion study, and 24-h urine catecholamine levels were evaluated. {sup 123}I-MIBG SPET was performed at 30 min and 4 h following injection of 3 mCi of {sup 123}I-MIBG in groups I and II and in normal subjects (n=4). On planar images, the heart to mediastinum (H/M) ratio was measured. Defect pattern and severity of MIBG uptake were qualitatively analysed on SPET. Compared with control subjects, diabetic patients had a reduced H/M ratio regardless of the presence of clinical autonomic neuropathy. There was no difference in H/M ratio between groups I and II. On SPET images, focal or diffuse defects were demonstrated in all patients in group I, and in five of the six patients in group II. The extent of defects tended to be more pronounced in group I than in group II. In conclusion, {sup 123}I-MIBG scan was found to be a more sensitive method than clinical autonomic nervous function tests for the detection of autonomic neuropathy in diabetes. (orig.). With 3 figs., 1 tab.

  5. Impact of sympathetic nervous system activity on post-exercise flow-mediated dilatation in humans.

    NARCIS (Netherlands)

    Atkinson, C.L.; Lewis, N.C.; Carter, H.H.; Thijssen, D.H.J.; Ainslie, P.N.; Green, D.J.

    2015-01-01

    KEY POINTS: Previous studies indicate a transient reduction in arterial function following large muscle group exercise, but the mechanisms involved are unknown. Sympathetic nervous system activation may contribute to such reductions through direct effects in the artery wall, or because of decreases

  6. Cortisol and Children's Adjustment: The Moderating Role of Sympathetic Nervous System Activity

    Science.gov (United States)

    El-Sheikh, Mona; Erath, Stephen A.; Buckhalt, Joseph A.; Granger, Douglas A.; Mize, Jacquelyn

    2008-01-01

    We examined relations among cortisol, markers of sympathetic nervous system (SNS) activity (including salivary alpha-amylase and skin conductance level), and children's adjustment. We also tested the Bauer et al. ("Journal of Developmental and Behavioral Pediatrics," 23(2), 102-113, 2002) hypothesis that interactions between the SNS and cortisol…

  7. Tonic activity of carotid body chemoreceptors contributes to the increased sympathetic drive in essential hypertension.

    Science.gov (United States)

    Siński, Maciej; Lewandowski, Jacek; Przybylski, Jacek; Bidiuk, Joanna; Abramczyk, Piotr; Ciarka, Agnieszka; Gaciong, Zbigniew

    2012-05-01

    Carotid chemoreceptors provoke an increase in muscle sympathetic nerve activation (MSNA) in response to hypoxia; they are also tonically active during normoxic breathing. The contribution of peripheral chemoreceptors to sympathetic activation in hypertension is incompletely understood. The aim of our study was to investigate the effect of chemoreceptor deactivation on sympathetic activity in untreated patients with hypertension. A total of 12 untreated hypertensive males and 11 male controls participated in this randomized, crossover, placebo-controlled study. MSNA, systolic blood pressure(BP), diastolic BP, heart rate (HR), electrocardiogram, hemoglobin oxygen saturation (Sat%) and respiratory movements were measured during repeated 10-min periods of respiration with 100% oxygen or 21% oxygen in a blinded fashion. Compared with controls, hypertensives had higher resting MSNA (38 ± 10 vs. 29 ± 0.9 burst per min, Pchemoreceptor deactivation with hyperoxia. HR decreased and Sat% increased in both the study groups. These results confirm the role of tonic chemoreceptor drive in the development of sympathetic overactivity in hypertension.

  8. Sympathetic nervous system activation, arterial shear rate, and flow-mediated dilation.

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Atkinson, C.L.; Ono, K.; Sprung, V.S.; Spence, A.L.; Pugh, C.J.; Green, D.J.

    2014-01-01

    The aim of this study was to examine the contribution of arterial shear to changes in flow-mediated dilation (FMD) during sympathetic nervous system (SNS) activation in healthy humans. Ten healthy men reported to our laboratory four times. Bilateral FMD, shear rate (SR), and catecholamines were exam

  9. Is kidney ischemia the central mechanism in parallel activation of the renin and sympathetic system?

    NARCIS (Netherlands)

    Siddiqi, Laima; Joles, Jaap A.; Grassi, Guido; Blankestijn, Peter J.

    2009-01-01

    In chronic kidney disease simultaneous activation of the renin - angiotensin and sympathetic systems occurs. Kidney ischemia seems to play a key role in the pathogenesis. This review firstly summarizes experimental and clinical evidence in chronic kidney disease supporting this idea and addresses th

  10. Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans

    NARCIS (Netherlands)

    Kox, M.; Eijk, L.T.G.J. van; Zwaag, J.; Wildenberg, J. van den; Sweep, F.C.; Hoeven, J.G. van der; Pickkers, P.

    2014-01-01

    Excessive or persistent proinflammatory cytokine production plays a central role in autoimmune diseases. Acute activation of the sympathetic nervous system attenuates the innate immune response. However, both the autonomic nervous system and innate immune system are regarded as systems that cannot b

  11. Enhanced sympathetic arousal in response to FMRI scanning correlates with task induced activations and deactivations.

    Directory of Open Access Journals (Sweden)

    Markus Muehlhan

    Full Text Available It has been repeatedly shown that functional magnetic resonance imaging (fMRI triggers distress and neuroendocrine response systems. Prior studies have revealed that sympathetic arousal increases, particularly at the beginning of the examination. Against this background it appears likely that those stress reactions during the scanning procedure may influence task performance and neural correlates. However, the question how sympathetic arousal elicited by the scanning procedure itself may act as a potential confounder of fMRI data remains unresolved today. Thirty-seven scanner naive healthy subjects performed a simple cued target detection task. Levels of salivary alpha amylase (sAA, as a biomarker for sympathetic activity, were assessed in samples obtained at several time points during the lab visit. SAA increased two times, immediately prior to scanning and at the end of the scanning procedure. Neural activation related to motor preparation and timing as well as task performance was positively correlated with the first increase. Furthermore, the first sAA increase was associated with task induced deactivation (TID in frontal and parietal regions. However, these effects were restricted to the first part of the experiment. Consequently, this bias of scanner related sympathetic activation should be considered in future fMRI investigations. It is of particular importance for pharmacological investigations studying adrenergic agents and the comparison of groups with different stress vulnerabilities like patients and controls or adolescents and adults.

  12. Acute electromyostimulation decreases muscle sympathetic nerve activity in patients with advanced chronic heart failure (EMSICA Study.

    Directory of Open Access Journals (Sweden)

    Marc Labrunée

    Full Text Available BACKGROUND: Muscle passive contraction of lower limb by neuromuscular electrostimulation (NMES is frequently used in chronic heart failure (CHF patients but no data are available concerning its action on sympathetic activity. However, Transcutaneous Electrical Nerve Stimulation (TENS is able to improve baroreflex in CHF. The primary aim of the present study was to investigate the acute effect of TENS and NMES compared to Sham stimulation on sympathetic overactivity as assessed by Muscle Sympathetic Nerve Activity (MSNA. METHODS: We performed a serie of two parallel, randomized, double blinded and sham controlled protocols in twenty-two CHF patients in New York Heart Association (NYHA Class III. Half of them performed stimulation by TENS, and the others tested NMES. RESULTS: Compare to Sham stimulation, both TENS and NMES are able to reduce MSNA (63.5 ± 3.5 vs 69.7 ± 3.1 bursts / min, p < 0.01 after TENS and 51.6 ± 3.3 vs 56.7 ± 3.3 bursts / min, p < 0, 01 after NMES. No variation of blood pressure, heart rate or respiratory parameters was observed after stimulation. CONCLUSION: The results suggest that sensory stimulation of lower limbs by electrical device, either TENS or NMES, could inhibit sympathetic outflow directed to legs in CHF patients. These properties could benefits CHF patients and pave the way for a new non-pharmacological approach of CHF.

  13. Power Spectral Density Analysis of Electrodermal Activity for Sympathetic Function Assessment.

    Science.gov (United States)

    Posada-Quintero, Hugo F; Florian, John P; Orjuela-Cañón, Alvaro D; Aljama-Corrales, Tomas; Charleston-Villalobos, Sonia; Chon, Ki H

    2016-10-01

    Time-domain features of electrodermal activity (EDA), the measurable changes in conductance at the skin surface, are typically used to assess overall activation of the sympathetic system. These time domain features, the skin conductance level (SCL) and the nonspecific skin conductance responses (NS.SCRs), are consistently elevated with sympathetic nervous arousal, but highly variable between subjects. A novel frequency-domain approach to quantify sympathetic function using the power spectral density (PSD) of EDA is proposed. This analysis was used to examine if some of the induced stimuli invoke the sympathetic nervous system's dynamics which can be discernible as a large spectral peak, conjectured to be present in the low frequency band. The resulting indices were compared to the power of low-frequency components of heart rate variability (HRVLF) time series, as well as to time-domain features of EDA. Twelve healthy subjects were subjected to orthostatic, physical and cognitive stress, to test these techniques. We found that the increase in the spectral powers of the EDA was largely confined to 0.045-0.15 Hz, which is in the prescribed band for HRVLF. These low frequency components are known to be, in part, influenced by the sympathetic nervous dynamics. However, we found an additional 5-10% of the spectral power in the frequency range of 0.15-0.25 Hz with all three stimuli. Thus, dynamics of the normalized sympathetic component of the EDA, termed EDASympn, are represented in the frequency band 0.045-0.25 Hz; only a small amount of spectral power is present in frequencies higher than 0.25 Hz. Our results showed that the time-domain indices (the SCL and NS.SCRs), and EDASympn, exhibited significant increases under orthostatic, physical, and cognitive stress. However, EDASympn was more responsive than the SCL and NS.SCRs to the cold pressor stimulus, while the latter two were more sensitive to the postural and Stroop tests. Additionally, EDASympn exhibited an

  14. Autonomic Nervous System Responses to Viewing Green and Built Settings: Differentiating Between Sympathetic and Parasympathetic Activity

    Science.gov (United States)

    van den Berg, Magdalena M.H.E.; Maas, Jolanda; Muller, Rianne; Braun, Anoek; Kaandorp, Wendy; van Lien, René; van Poppel, Mireille N.M.; van Mechelen, Willem; van den Berg, Agnes E.

    2015-01-01

    This laboratory study explored buffering and recovery effects of viewing urban green and built spaces on autonomic nervous system activity. Forty-six students viewed photos of green and built spaces immediately following, and preceding acute stress induction. Simultaneously recorded electrocardiogram and impedance cardiogram signal was used to derive respiratory sinus arrhythmia (RSA) and pre-ejection period (PEP), indicators of respectively parasympathetic and sympathetic activity. The findings provide support for greater recovery after viewing green scenes, as marked by a stronger increase in RSA as a marker of parasympathetic activity. There were no indications for greater recovery after viewing green scenes in PEP as a marker of sympathetic activity, and there were also no indications of greater buffering effects of green space in neither RSA nor PEP. Overall, our findings are consistent with a predominant role of the parasympathetic nervous system in restorative effects of viewing green space. PMID:26694426

  15. Autonomic Nervous System Responses to Viewing Green and Built Settings: Differentiating Between Sympathetic and Parasympathetic Activity

    Directory of Open Access Journals (Sweden)

    Magdalena M.H.E. van den Berg

    2015-12-01

    Full Text Available This laboratory study explored buffering and recovery effects of viewing urban green and built spaces on autonomic nervous system activity. Forty-six students viewed photos of green and built spaces immediately following, and preceding acute stress induction. Simultaneously recorded electrocardiogram and impedance cardiogram signal was used to derive respiratory sinus arrhythmia (RSA and pre-ejection period (PEP, indicators of respectively parasympathetic and sympathetic activity. The findings provide support for greater recovery after viewing green scenes, as marked by a stronger increase in RSA as a marker of parasympathetic activity. There were no indications for greater recovery after viewing green scenes in PEP as a marker of sympathetic activity, and there were also no indications of greater buffering effects of green space in neither RSA nor PEP. Overall, our findings are consistent with a predominant role of the parasympathetic nervous system in restorative effects of viewing green space.

  16. Effects of Renal Denervation on Sympathetic Activation, Blood Pressure and Glucose Metabolism in Patients with Resistant Hypertension

    Directory of Open Access Journals (Sweden)

    Markus Peter Schlaich

    2012-02-01

    Full Text Available Increased central sympathetic drive is a hallmark of a number of important and common clinical conditions including essential hypertension, insulin resistance, heart failure, and chronic kidney disease. Afferent signalling from the kidney via sensory nerves has been identified as an important contributor and underlying cause of elevated central sympathetic drive, which in turn increases efferent sympathetic outflow to the kidney and other organs crucially involved in cardiovascular control. The resulting effects on renal haemodynamics, sodium and water retention and renin release contribute to the blood pressure rise and other adverse consequences of sustained sympathetic activation and identify the renal nerves as a logical therapeutic target. Recent clinical studies using catheter based radiofrequency ablation technology to achieve functional renal denervation in patients with resistant hypertension have exposed the sympathetic link between these conditions and indicate that this approach may provide a safe and effective treatment alternative for resistant hypertension and its adverse consequences.

  17. Sympathetic activity in the rat: effects of anaesthesia on noradrenaline kinetics.

    Science.gov (United States)

    Maignan, E; Dong, W X; Legrand, M; Safar, M; Cuche, J L

    2000-04-12

    Noradrenaline (NA) kinetics represent an effective tool for evaluating the activity of the sympathetic system: thus plasma NA concentration, spillover rate (SOR) and metabolic clearance rate (MC) were measured in the rat. The dilution technique was adapted and validated: pithing that caused mechanical destruction of the spinal cord was shown to reduce drastically NA-SOR and plasma NA concentration with no effect on NA-MC. NA-SOR and plasma NA concentration were restored within their normal limits when 2.5 Hz electrical stimulation of the sympathetic roots was superimposed. Normal values of NA kinetics in non-anaesthetised normotensive 12-week-old rats are reported: NA-SOR=196.1+/-26.4 ng/kg/min, NA-MC=413.9+/-38.8 ml/kg/min and plasma NA=486+/-52 pg/ml. NA kinetic was investigated in response to anaesthesia, known to depress excitable tissues of the central nervous system and expected to depress the activity of the sympathetic system. When NA-SOR was significantly reduced during anaesthesia with either sodium pentobarbital or chloralose, plasma NA concentration was not changed because NA-MC was also reduced. Thus, plasma NA concentration can be a misleading marker of the sympathetic activity. The response of the sympathetic activity to four different anaesthetic agents is shown to be heterogeneous, ranging from inhibition to stimulation. Sodium pentobarbital anaesthesia was associated with a statistically significant reduction of both NA-SOR (105.6+/-14.1 ng/kg/min, P<0. 01) and NA-MC (239.3+/-18.7 ml/kg/min, P<0.001) while plasma NA was not changed (438+/-47 pg/ml). Chloralose reduced NA-SOR (101.6+/-20. 1 ng/kg/min, P<0.05) while ketamine did not (150.6+/-35.5 ng/kg/min, n.s.): both compounds reduced NA-MC (257.9+/-27.8 ml/kg/min, P<0.01 and 265.8+/-34.3 ml/kg/min, P<0.05, respectively). Diethyl ether was shown to increase both NA-SOR (472.2+/-111 ng/kg/min, P<0.05) and plasma NA concentration (1589+/-436 pg/ml, P<0.01), while NA-MC remained unchanged. Thus, any

  18. Sympathetic activity induced by naloxone-precipitated morphine withdrawal is blocked in genetically engineered mice lacking functional CRF1 receptor

    Energy Technology Data Exchange (ETDEWEB)

    García-Carmona, Juan-Antonio; Martínez-Laorden, Elena; Milanés, María-Victoria; Laorden, María-Luisa

    2015-02-15

    There is large body evidence indicating that stress can lead to cardiovascular disease. However, the exact brain areas and the mechanisms involved remain to be revealed. Here, we performed a series of experiments to characterize the role of CRF1 receptor (CRF1R) in the stress response induced by naloxone-precipitated morphine withdrawal. The experiments were performed in the hypothalamic paraventricular nucleus (PVN) ventrolateral medulla (VLM), brain regions involved in the regulation of cardiovascular activity, and in the right ventricle by using genetically engineered mice lacking functional CRF1R levels (KO). Mice were treated with increasing doses of morphine and withdrawal was precipitated by naloxone administration. Noradrenaline (NA) turnover, c-Fos, expression, PKA and TH phosphorylated at serine 40, was evaluated by high-performance liquid chromatography (HPLC), immunohistochemistry and immunoblotting. Morphine withdrawal induced an enhancement of NA turnover in PVN in parallel with an increase in TH neurons expressing c-Fos in VLM in wild-type mice. In addition we have demonstrated an increase in NA turnover, TH phosphorylated at serine 40 and PKA levels in heart. The main finding of the present study was that NA turnover, TH positive neurons that express c-Fos, TH phosphorylated at serine 40 and PKA expression observed during morphine withdrawal were significantly inhibited in CRF1R KO mice. Our results demonstrate that CRF/CRF1R activation may contribute to the adaptive changes induced by naloxone-precipitated withdrawal in the heart and in the brain areas which modulate the cardiac sympathetic function and suggest that CRF/CRF1R pathways could be contributing to cardiovascular disease associated to opioid addiction. - Highlights: • Naloxone-precipitated morphine withdrawal increases sympathetic activity in the PVN and heart. • Co-localization of TH phosphorylated at serine 40/c-Fos in the VLM after morphine withdrawal • Naloxone

  19. Liver afferents contribute to water drinking-induced sympathetic activation in human subjects: a clinical trial.

    Directory of Open Access Journals (Sweden)

    Marcus May

    Full Text Available UNLABELLED: Water drinking acutely increases sympathetic activity in human subjects. In animals, the response appears to be mediated through transient receptor potential channel TRPV4 activation on osmosensitive hepatic spinal afferents, described as osmopressor response. We hypothesized that hepatic denervation attenuates water drinking-induced sympathetic activation. We studied 20 liver transplant recipients (44±2.6 years, 1.2±0.1 years post transplant as model of hepatic denervation and 20 kidney transplant recipients (43±2.6 years, 0.8±0.1 years post transplant as immunosuppressive drug matched control group. Before and after 500 ml water ingestion, we obtained venous blood samples for catecholamine analysis. We also monitored brachial and finger blood pressure, ECG, and thoracic bioimpedance. Plasma norepinephrine concentration had changed by 0.01±0.07 nmol/l in liver and by 0.21±0.07 nmol/l in kidney transplant recipients (p<0.05 between groups after 30-40 minutes of water drinking. While blood pressure and systemic vascular resistance increased in both groups, the responses tended to be attenuated in liver transplant recipients. Our findings support the idea that osmosensitive hepatic afferents are involved in water drinking-induced sympathetic activation in human subjects. TRIAL REGISTRATION: ClinicalTrials.gov NCT01237431.

  20. Sympathetic Activation Induces Skeletal Fgf23 Expression in a Circadian Rhythm-dependent Manner*

    Science.gov (United States)

    Kawai, Masanobu; Kinoshita, Saori; Shimba, Shigeki; Ozono, Keiichi; Michigami, Toshimi

    2014-01-01

    The circadian clock network is well known to link food intake and metabolic outputs. Phosphorus is a pivotal nutritional factor involved in energy and skeletal metabolisms and possesses a circadian profile in the circulation; however, the precise mechanisms whereby phosphate metabolism is regulated by the circadian clock network remain largely unknown. Because sympathetic tone, which displays a circadian profile, is activated by food intake, we tested the hypothesis that phosphate metabolism was regulated by the circadian clock network through the modification of food intake-associated sympathetic activation. Skeletal Fgf23 expression showed higher expression during the dark phase (DP) associated with elevated circulating FGF23 levels and enhanced phosphate excretion in the urine. The peaks in skeletal Fgf23 expression and urine epinephrine levels, a marker for sympathetic tone, shifted from DP to the light phase (LP) when mice were fed during LP. Interestingly, β-adrenergic agonist, isoproterenol (ISO), induced skeletal Fgf23 expression when administered at ZT12, but this was not observed in Bmal1-deficient mice. In vitro reporter assays revealed that ISO trans-activated Fgf23 promoter through a cAMP responsive element in osteoblastic UMR-106 cells. The mechanism of circadian regulation of Fgf23 induction by ISO in vivo was partly explained by the suppressive effect of Cryptochrome1 (Cry1) on ISO signaling. These results indicate that the regulation of skeletal Fgf23 expression by sympathetic activity is dependent on the circadian clock system and may shed light on new regulatory networks of FGF23 that could be important for understanding the physiology of phosphate metabolism. PMID:24302726

  1. Leptin into the rostral ventral lateral medulla (RVLM) augments renal sympathetic nerve activity and blood pressure

    OpenAIRE

    Barnes, Maria J.; David Harry McDougal

    2014-01-01

    Leptin is a hormone released from adipose tissue. While this hormone normally acts to reduce feeding behavior and increase energy expenditure, in obesity, resistance to these effects occurs even though the hormone is released in large amounts. Although leptin no longer works to suppress feeding in the obese, leptin retains its potent effects on other autonomic functions such as blood pressure regulation. Leptin has been associated with hypertension and increased sympathetic autonomic activ...

  2. Leptin into the rostral ventral lateral medulla (RVLM) augments renal sympathetic nerve activity and blood pressure

    OpenAIRE

    Barnes, Maria J.; McDougal, David H.

    2014-01-01

    Leptin is a hormone released from adipose tissue. While this hormone normally acts to reduce feeding behavior and increase energy expenditure, in obesity, resistance to these effects occurs even though the hormone is released in large amounts. Although leptin no longer works to suppress feeding in the obese, leptin retains its potent effects on other autonomic functions such as blood pressure regulation. Leptin has been associated with hypertension and increased sympathetic autonomic activity...

  3. Effects of tiotropium on sympathetic activation during exercise in stable chronic obstructive pulmonary disease patients

    Directory of Open Access Journals (Sweden)

    Kitada S

    2012-05-01

    Full Text Available Kenji Yoshimura, Ryoji Maekura, Toru Hiraga, Seigo Kitada, Keisuke Miki, Mari Miki, Yoshitaka TateishiDepartment of Respiratory Medicine, Toneyama National Hospital, Osaka, JapanBackground: Tiotropium partially relieves exertional dyspnea and reduces the risk of congestive heart failure in chronic obstructive pulmonary disease (COPD patients. However, its effect on the sympathetic activation response to exercise is unknown.Aims: This study aimed to determine whether tiotropium use results in a sustained reduction in sympathetic activation during exercise.Methods: We conducted a 12-week, open-label (treatments: tiotropium 18 µg or oxitropium 0.2 mg × 3 mg, crossover study in 17 COPD patients. Treatment order was randomized across subjects. The subjects underwent a pulmonary function test and two modes of cardiopulmonary exercise (constant work rate and incremental exercise testing using a cycle ergometer, with measurement of arterial catecholamines after each treatment period.Results: Forced expiratory volume in 1 second and forced vital capacity were significantly larger in the tiotropium treatment group. In constant exercise testing, exercise endurance time was longer, with improvement in dyspnea during exercise and reduction in dynamic hyperinflation in the tiotropium treatment group. Similarly, in incremental exercise testing, exercise time, carbon dioxide production, and minute ventilation at peak exercise were significantly higher in the tiotropium treatment group. Plasma norepinephrine concentrations and dyspnea intensity were also lower during submaximal isotime exercise and throughout the incremental workload exercise in the tiotropium treatment group.Conclusion: Tiotropium suppressed the increase of sympathetic activation during exercise at the end of the 6-week treatment, as compared with the effect of oxipropium. This effect might be attributed to improvement in lung function and exercise capacity and reduction in exertional dyspnea

  4. Skin sympathetic nerve activity in humans during exposure to emotionally-charged images: sex differences

    OpenAIRE

    Brown, Rachael; Macefield, Vaughan G.

    2014-01-01

    While it is known that anxiety or emotional arousal affects skin sympathetic nerve activity (SSNA), the galvanic skin response (GSR) is the most widely used parameter to infer increases in SSNA during stress or emotional studies. We recently showed that SSNA provides a more sensitive measure of emotional state than effector-organ responses. The aim of the present study was to assess whether there are gender differences in the responses of SSNA and other physiological parameters such as blood ...

  5. Modulation of muscle sympathetic nerve activity to muscle heating during dynamic exercise

    OpenAIRE

    Cook, Jonathan S.; Ray, Chester A.

    2009-01-01

    Previous studies from our laboratory have demonstrated that altering muscle temperature of the exercising forearm can elicit changes in muscle sympathetic nerve activity (MSNA) during ischemic isometric handgrip. The purpose of the current study was to determine the interactive effect of muscle temperature and blood flow on MSNA responses during dynamic handgrip (DHG). Eight subjects performed two bouts of graded DHG to fatigue followed by 2 min of postexercise muscle ischemia (PEMI). Local h...

  6. Evaluation of cardiac sympathetic nervous function by {sup 123}I-metaiodobenzylguanidine scintigraphy in insulin-treated non-insulin dependent diabetics with hypoglycemia unawareness

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Tomio; Toyama, Takuji; Hoshizaki, Hiroshi [Gunma Prefectural Cardiovascular Center, Maebashi (Japan)] [and others

    1996-02-01

    The association between the lack of adrenergic symptoms during hypoglycemia and myocardial {sup 123}I-metaiodobenzylguanidine (MIBG) accumulation was investigated in 12 insulin-treated non-insulin-dependent diabetes mellitus (NIDDM) patients who had no evidence of heart disease. These patients were divided into 2 groups according to the presence (group A) or absence (group B) of adrenergic symptoms during hypoglycemia. Autonomic function tests revealed significantly severe autonomic dysfunction in group B compared to that in group A. Insulin infusion test indicated no significant difference in the catecholamine response between the two groups. {sup 123}I-MIBG scintigraphy showed that the heart/mediastinum ratio of MIBG uptake was significantly lower, and scintigraphic defect was greater in group B than in group A. There were no significant differences in the washout rate between the two groups. These results suggested that the lack of adrenergic symptoms during hypoglycemia may be associated with cardiac sympathetic nervous dysfunction in insulin-treated NIDDM patients, and this dysfunction is mainly due to cardiac sympathetic denervation. (author).

  7. Evaluation of cardiac sympathetic nervous function by 123I-metaiodobenzylguanidine scintigraphy in insulin-treated non-insulin dependent diabetics with hypoglycemia unawareness

    International Nuclear Information System (INIS)

    The association between the lack of adrenergic symptoms during hypoglycemia and myocardial 123I-metaiodobenzylguanidine (MIBG) accumulation was investigated in 12 insulin-treated non-insulin-dependent diabetes mellitus (NIDDM) patients who had no evidence of heart disease. These patients were divided into 2 groups according to the presence (group A) or absence (group B) of adrenergic symptoms during hypoglycemia. Autonomic function tests revealed significantly severe autonomic dysfunction in group B compared to that in group A. Insulin infusion test indicated no significant difference in the catecholamine response between the two groups. 123I-MIBG scintigraphy showed that the heart/mediastinum ratio of MIBG uptake was significantly lower, and scintigraphic defect was greater in group B than in group A. There were no significant differences in the washout rate between the two groups. These results suggested that the lack of adrenergic symptoms during hypoglycemia may be associated with cardiac sympathetic nervous dysfunction in insulin-treated NIDDM patients, and this dysfunction is mainly due to cardiac sympathetic denervation. (author)

  8. Hypothalamic Nesfatin-1 Stimulates Sympathetic Nerve Activity via Hypothalamic ERK Signaling.

    Science.gov (United States)

    Tanida, Mamoru; Gotoh, Hitoshi; Yamamoto, Naoki; Wang, Mofei; Kuda, Yuhichi; Kurata, Yasutaka; Mori, Masatomo; Shibamoto, Toshishige

    2015-11-01

    Nesfatin-1 acts on the hypothalamus and regulates the autonomic nervous system. However, the hypothalamic mechanisms of nesfatin-1 on the autonomic nervous system are not well understood. In this study, we found that intracerebroventricular (ICV) administration of nesfatin-1 increased the extracellular signal-regulated kinase (ERK) activity in rats. Furthermore, the activity of sympathetic nerves, in the kidneys, liver, and white adipose tissue (WAT), and blood pressure was stimulated by the ICV injection of nesfatin-1, and these effects were abolished owing to pharmacological inhibition of ERK. Renal sympathoexcitatory and hypertensive effects were also observed with nesfatin-1 microinjection into the paraventricular hypothalamic nucleus (PVN). Moreover, nesfatin-1 increased the number of phospho (p)-ERK1/2-positive neurons in the PVN and coexpression of the protein in neurons expressing corticotropin-releasing hormone (CRH). Pharmacological blockade of CRH signaling inhibited renal sympathetic and hypertensive responses to nesfatin-1. Finally, sympathetic stimulation of WAT and increased p-ERK1/2 levels in response to nesfatin-1 were preserved in obese animals such as rats that were fed a high-fat diet and leptin receptor-deficient Zucker fatty rats. These findings indicate that nesfatin-1 regulates the autonomic nervous system through ERK signaling in PVN-CRH neurons to maintain cardiovascular function and that the antiobesity effect of nesfatin-1 is mediated by hypothalamic ERK-dependent sympathoexcitation in obese animals. PMID:26310564

  9. Change in hormones reflecting sympathetic activity in the Finnish sauna.

    Science.gov (United States)

    Lammintausta, R; Syvälahti, E; Pekkarinen, A

    1976-08-01

    The effects of the high temperature (80-120 degrees C) of the Finnish Sauna bath on the concentrations of growth hormone, immunoreactive insulin and renin activity in plasma, on blood glucose and on the urinary excretion of aldosterone, vanilmandelic acid and sodium of 55 healthy volunteers were studied. There was a significant increase in mean heart rate (62%), serum growth hormone (142%) and plasma renin activity (95%) in the Sauna. One hour after the Sauna bath the mean serum growth hormone had returned to the control level while plasma renin activity still remained higher (p less than 0.05) than before the Sauna bath. The serum insulin, blood sugar and urinary excretion of aldosterone and VMA did not change during or after Sauna bath. The urinary sodium excretion decreased significantly after the Sauna bath and the decrease was most striking (46%) during the first 6-hour period from the beginning of Sauna bath. Plasma renin activity values correlated positively with 12-hour urinary VMA excretion (p less than 0.01) and negatively with 6-hour urinary sodium excretion (p less than 0.05) before and after Sauna, suggesting the role of catecholamines and sodium depletion in renin response in Sauna.

  10. Adrenal G protein-coupled receptor kinase-2 in regulation of sympathetic nervous system activity in heart failure

    Institute of Scientific and Technical Information of China (English)

    Katie; A; Mc; Crink; Ava; Brill; Anastasios; Lymperopoulos

    2015-01-01

    Heart failure(HF), the number one cause of death in the western world, is caused by the insufficient performance of the heart leading to tissue underperfusion in response to an injury or insult. It comprises complex interactions between important neurohormonal mechanisms that try but ultimately fail to sustain cardiac output. The most prominent such mechanism is the sympathetic(adrenergic) nervous system(SNS), whose activity and outflow are greatly elevated in HF. SNS hyperactivity confers significant toxicity to the failing heart and markedly increases HF morbidity and mortality via excessive activation of adrenergic receptors, which are G protein-coupled receptors. Thus, ligand binding induces their coupling to heterotrimeric G proteins that transduce intracellular signals. G protein signaling is turned-off by the agonist-bound receptor phosphorylation courtesy of G protein-coupled receptor kinases(GRKs), followed by βarrestin binding, which prevents the GRK-phosphorylated receptor from further interaction with the G proteins and simultaneously leads it inside the cell(receptor sequestration). Recent evidence indicates that adrenal GRK2 and βarrestins can regulate adrenal catecholamine secretion, thereby modulating SNS activity in HF. The present review gives an account of all these studies on adrenal GRKs and βarrestins in HF and discusses the exciting new therapeutic possibilities for chronic HF offered by targeting these proteins pharmacologically.

  11. [Drug with a high metabolic activity, cocarnit, in the treatment of diabetic cardiac autonomic neuropathy].

    Science.gov (United States)

    Popov, S V; Melekhovets', O K; Demikhova, N V; Vynnychenko, L B

    2012-01-01

    Left ventricular diastolic dysfunction in patients with diabetes is formed in the absence of atherosclerotic changes as a consequence of diabetic cardiac autonomic neuropathy in the early stages of diabetes. Progression of autonomic cardiac neuropathy in cardio-vascular type is associated with the violation of energy supply of cells, protein synthesis, electrolyte exchange, the exchange of trace elements, oxidation reduction processes, oxygen-transport function of blood, so that metabolic therapy is carried out to optimize the processes of formation and energy costs. The drug cocarnit activates processes of aerobic oxidation of glucose, as well as providing regulatory influence on the oxidation of fatty acids. Applying of cocarnit in complex therapy in patients with diabetic cardiac autonomic neuropathy found improvement of left ventricular diastolic function, and positive dynamics in the efferent activity balance of the sympathetic and parasympathetic control of heart rate variability, which provides the regression of clinical symptoms. PMID:23356142

  12. Increased Feeding Speed Is Associated with Higher Subsequent Sympathetic Activity in Dogs.

    Directory of Open Access Journals (Sweden)

    Nobuyo Ohtani

    Full Text Available Although the domestication process has altered the feeding behavior of dogs, some breeds still demonstrate a remarkable ability to gorge, and will eat exceptionally large quantities of food whenever it is available. Lesions in the ventromedial hypothalamus increase appetite and lead to obesity, suggesting that the autonomic nervous system plays an important role in feeding. Focusing on the autonomic activities closely involved in food intake, we investigated sympathetic activities before and after feeding in dogs. The subjects were 56 healthy dogs of 21 different breeds (29 males and 27 females. Based on feeding habits, the 56 dogs were divided into three groups: Fast (n = 19, Slow (n = 24 and Leftover (n = 13. The feeding speed and the amount of food per mouthful of the Fast dogs were significantly greater than those of the Slow and the Leftover dogs. The plasma norepinephrine level in dogs of the Fast group was significantly increased after feeding, while those in the Slow and Leftover groups were significantly decreased after feeding, compared with the pre-feeding concentrations. The low frequency/high frequency ratio of heart rate variability is a good indicator of sympathetic activity and was also significantly higher in the Fast group than in the other groups. Delayed feeding using automatic feeding equipment decreased the plasma norepinephrine concentration and low frequency/high frequency ratio observed after feeding in dogs of the Fast group. In conclusion, dogs eating rapidly with less chewing, which indicates increased sympathetic activity during feeding, may benefit from delayed feeding. The slow eating may activate the parasympathetic nervous system after feeding, which could enhance the activity of the digestive system.

  13. Direct conscious telemetry recordings demonstrate increased renal sympathetic nerve activity in rats with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Ibrahim M Salman

    2015-08-01

    Full Text Available Chronic kidney disease (CKD is associated with sympathetic hyperactivity and impaired blood pressure control reflex responses, yet direct evidence demonstrating these features of autonomic dysfunction in conscious animals is still lacking. Here we measured renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP using telemetry-based recordings in a rat model of CKD, the Lewis Polycystic Kidney (LPK rat, and assessed responses to chemoreflex activation and acute stress. Male LPK and Lewis control animals (total n=16 were instrumented for telemetric recording of RSNA and MAP. At 12–13 weeks-of-age, resting RSNA and MAP, sympathetic and haemodynamic responses to both peripheral (hypoxia: 10% O2 and central chemoreflex (hypercapnia: 7% CO2 activation and acute stress (open-field exposure, were measured. As indicators of renal function, urinary protein (UPro and creatinine (Ucr levels were assessed. LPK rats had higher resting RSNA (1.2±0.1 vs. 0.6±0.1 µV, p<0.05 and MAP (151±8 vs. 97±2 mmHg, p<0.05 compared to Lewis. MAP was negatively correlated with Ucr (r=-0.80, p=0.002 and positively correlated with RSNA (r=0.66, p=0.014, with multiple linear regression modeling indicating the strongest correlation was with Ucr. RSNA and MAP responses to activation of the central chemoreflex and open-field stress were reduced in the LPK relative to the Lewis (all p<0.05. This is the first description of dual conscious telemetry recording of RSNA and MAP in a genetic rodent model of CKD. Elevated RSNA is likely a key contributor to the marked hypertension in this model, while attenuated RSNA and MAP responses to central chemoreflex activation and acute stress in the LPK indicate possible deficits in the neural processing of autonomic outflows evoked by these sympathoexcitatory pathways.

  14. Evidence for a curvilinear relationship between sympathetic nervous system activation and women's physiological sexual arousal.

    Science.gov (United States)

    Lorenz, Tierney Ahrold; Harte, Christopher B; Hamilton, Lisa Dawn; Meston, Cindy M

    2012-01-01

    There is increasing evidence that women's physiological sexual arousal is facilitated by moderate sympathetic nervous system (SNS) activation. Literature also suggests that the level of SNS activation may play a role in the degree to which SNS activity affects sexual arousal. We provide the first empirical examination of a possible curvilinear relationship between SNS activity and women's genital arousal using a direct measure of SNS activation in 52 sexually functional women. The relationship between heart rate variability (HRV), a specific and sensitive marker of SNS activation, and vaginal pulse amplitude (VPA), a measure of genital arousal, was analyzed. Moderate increases in SNS activity were associated with higher genital arousal, while very low or very high SNS activation was associated with lower genital arousal. These findings imply that there is an optimal level of SNS activation for women's physiological sexual arousal. PMID:22092348

  15. Carotid baroreceptor stimulation, sympathetic activity, baroreflex function, and blood pressure in hypertensive patients.

    NARCIS (Netherlands)

    Heusser, K.; Tank, J.; Engeli, S.; Diedrich, A.; Menne, J.; Eckert, S.; Peters, T.; Sweep, F.C.; Haller, H.; Pichlmaier, A.M.; Luft, F.C.; Jordan, J.

    2010-01-01

    In animals, electric field stimulation of carotid baroreceptors elicits a depressor response through sympathetic inhibition. We tested the hypothesis that the stimulation acutely reduces sympathetic vasomotor tone and blood pressure in patients with drug treatment-resistant arterial hypertension. Fu

  16. Leptin differentially increases sympathetic nerve activity and its baroreflex regulation in female rats: role of oestrogen.

    Science.gov (United States)

    Shi, Zhigang; Brooks, Virginia L

    2015-04-01

    Obesity and hypertension are commonly associated, and activation of the sympathetic nervous system is considered to be a major contributor, at least in part due to the central actions of leptin. However, while leptin increases sympathetic nerve activity (SNA) in males, whether leptin is equally effective in females is unknown. Here, we show that intracerebroventricular (i.c.v.) leptin increases lumbar (LSNA) and renal (RSNA) SNA and baroreflex control of LSNA and RSNA in α-chloralose anaesthetized female rats, but only during pro-oestrus. In contrast, i.c.v. leptin increased basal and baroreflex control of splanchnic SNA (SSNA) and heart rate (HR) in rats in both the pro-oestrus and dioestrus states. The effects of leptin on basal LSNA, RSNA, SSNA and HR were similar in males and pro-oestrus females; however, i.c.v. leptin increased mean arterial pressure (MAP) only in males. Leptin did not alter LSNA or HR in ovariectomized rats, but its effects were normalized with 4 days of oestrogen treatment. Bilateral nanoinjection of SHU9119 into the paraventricular nucleus of the hypothalamus (PVN), to block α-melanocyte-stimulating hormone (α-MSH) type 3 and 4 receptors, decreased LSNA in leptin-treated pro-oestrus but not dioestrus rats. Unlike leptin, i.c.v. insulin infusion increased basal and baroreflex control of LSNA and HR similarly in pro-oestrus and dioestrus rats; these responses did not differ from those in male rats. We conclude that, in female rats, leptin's stimulatory effects on SNA are differentially enhanced by oestrogen, at least in part via an increase in α-MSH activity in the PVN. These data further suggest that the actions of leptin and insulin to increase the activity of various sympathetic nerves occur via different neuronal pathways or cellular mechanisms. These results may explain the poor correlation in females of SNA with adiposity, or of MAP with leptin. PMID:25398524

  17. Use of iodine-123 metaiodobenzylguanidine scintigraphy to assess cardiac sympathetic denervation and the impact of hypertension in patients with non-insulin-dependent diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Koji; Nakatani, Yuko; Onishi, Satoshi [Dept. of Internal Medicine, Keihanna Hospital, Hirakata City, Osaka (Japan); Utsunomiya, Keita; Saika, Yoshinori [Dept. of Radiology, Keihanna Hospital, Hirakata City (Japan); Iwasaka, Toshiji [Cardiovascular Center, Kansai Medical University, Osaka (Japan)

    1999-10-01

    The objectives of this clinical study using iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy were (a) to evaluate cardiac sympathetic denervation in non-insulin-dependent diabetes mellitus (NIDDM) patients with and without hypertension and (b) to investigate the relation between cardiac sympathetic denervation and prognosis in NIDDM patients. We compared clinical characteristics and MIBG data [heart to mediastinum (H/M) ratio and % washout rate (WR)] in a control group and NIDDM patients with and without hypertension. MIBG scintigraphy was performed in 11 controls and 82 NIDDM patients without overt cardiovascular disease except for hypertension (systolic blood pressure {>=}140 and/or diastolic blood pressure {>=}90 mmHg). After MIBG examination, blood pressure was measured regularly in all NIDDM patients. There were significant differences between 65 normotensive and 17 hypertensive NIDDM patients with respect to age (55{+-}11 vs 63{+-}12 years, respectively, P<0.05), prevalence of diabetic retinopathy (12% vs 35%, respectively, P<0.05) and systolic blood pressure (120{+-}12 vs 145{+-}16 mmHg, respectively, P<0.001). The H/M ratio in hypertensive NIDDM patients was significantly lower than in the control group (1.81{+-}0.29 vs 2.27{+-}0.20, respectively, P<0.01). During the follow-up period (18{+-} 12 months), 17 NIDDM patients newly developed hypertension after MIBG examination. There were no significant differences in their clinical characteristics compared with persistently normotensive or hypertensive NIDDM patients. %WR in patients with new onset hypertension was significantly higher than in the control group (30.88%{+-}16.87% vs 12.89%{+-}11.94%, respectively, P<0.05). Moreover, in these patients %WR correlated with duration from the date of MIBG scintigraphy to the onset of hypertension (r=-0.512, P<0.05). Five NIDDM patients died during the follow-up period (four newly hypertensive patients and one normotensive patient). There were significant

  18. Evaluation of sympathetic activity by 123I-metaiodobenzylguanidine myocardial scintigraphy in dilated cardiomyopathy patients with sleep breathing disorder

    International Nuclear Information System (INIS)

    Because increased sympathetic nervous activity (SNA) in patients with dilated cardiomyopathy (DCM) associated with sleep breathing disorder (SBD) is known to deteriorate the prognosis of cardiac failure, 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was used as the investigative tool in the present study. The study group comprised 53 patients (47 men, 6 women; mean age 56±3 years) with chronic stable DCM. Patients were divided into SBD(+) or SBD(-) group according to 24-h pulse oximetry results. SBD(+) was defined when the 3% oxygen desaturation index was more than 15/h during sleep. In total, 32 patients were SBD(-) and 21 were SBD(+). In both groups, pulse oximetry were performed during sleep and awakening pulse rate, and measurement of the blood levels of catecholamines and B-type natriuretic peptide was performed. MIBG myocardial scintigraphy and echocardiography were performed at the same time. No significant difference was found between the 2 groups in catecholamine levels or left ventricular ejection fraction. However, MIBG had a significantly increased washout rate and a significantly decreased delayed heart to mediastinum ratio in the SBD(+) group compared with the SBD(-) group. SNA is increased in DCM patients when associated with SBD. MIBG myocardial scintigraphy may be a sensitive method of detecting increased SNA. (author)

  19. Functiogenesis of cardiac pacemaker activity.

    Science.gov (United States)

    Sakai, Tetsuro; Kamino, Kohtaro

    2016-07-01

    Throughout our investigations on the ontogenesis of the electrophysiological events in early embryonic chick hearts, using optical techniques to record membrane potential probed with voltage-sensitive dyes, we have introduced a novel concept of "functiogenesis" corresponding to "morphogenesis". This article gives an account of the framework of "functiogenesis", focusing on the cardiac pacemaker function and the functional organization of the pacemaking area. PMID:26719289

  20. Usefulness of 123I-Meta-iodobenzylguanidine (MIBG) myocardial scintigraphy for evaluation of cardiac sympathetic nervous system function in diabetic patients

    International Nuclear Information System (INIS)

    The cardiac sympathetic nervous system function of diabetic patients with no definite cardiovascular complications other than hypertension was evaluated by 123I -MIBG myocardial scintigraphy. The subjects consisted of 82 diabetic patients, 59 men, 23 women, mean age 57 years, 17 with hypertension and 65 with normal blood pressure, and they were compared with normal controls (8 men and 3 women, mean age 54 years). Myocardial scintigraphy was performed 10 minutes and 4 hours after administration of MIBG. The superior mediastinum and whole myocardium were set as regions of interest, and the heart-to-mediastinum ratio (H/M ratio) and the washout rate (%WR) were calculated. The mean observation period was 18±12 months, and 17 of the 65 diabetic patients with normal blood pressure before the study developed hypertension during the observation period. There were significant differences in H/M ratio and %WR between the diabetic patients and normal controls (H/M ratio; 1.96±0.34 vs 2.27±0.20, %WR; 24.71±16.99% vs 12.89±11.94). The diabetic patients with hypertension had higher morbidity with diabetic retinopathy and a lower H/M ratio. The 17 patients who developed hypertension during the observation period showed an increase in %WR and a reduction in the H/M ratio. Five patients who died during the observation period had a reduced H/M ratio and increased of %WR. 123I-MIBG myocardial scintigraphy in diabetic patients was shown to be useful for detecting cardiac sympathetic nervous system dysfunction, predicting the development of hypertension, and identifying patients who had a poor outcome. Diabetic patients with abnormal signals on MIBG myocardial scintigraphy need to be monitored much more carefully. (K.H.)

  1. Usefulness of {sup 123}I-Meta-iodobenzylguanidine (MIBG) myocardial scintigraphy for evaluation of cardiac sympathetic nervous system function in diabetic patients.

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Koji; Nakatani, Yuko; Doi, Kenji; Adachi, Gakuji; Takada, Kou

    2001-11-01

    The cardiac sympathetic nervous system function of diabetic patients with no definite cardiovascular complications other than hypertension was evaluated by {sup 123}I -MIBG myocardial scintigraphy. The subjects consisted of 82 diabetic patients, 59 men, 23 women, mean age 57 years, 17 with hypertension and 65 with normal blood pressure, and they were compared with normal controls (8 men and 3 women, mean age 54 years). Myocardial scintigraphy was performed 10 minutes and 4 hours after administration of MIBG. The superior mediastinum and whole myocardium were set as regions of interest, and the heart-to-mediastinum ratio (H/M ratio) and the washout rate (%WR) were calculated. The mean observation period was 18{+-}12 months, and 17 of the 65 diabetic patients with normal blood pressure before the study developed hypertension during the observation period. There were significant differences in H/M ratio and %WR between the diabetic patients and normal controls (H/M ratio; 1.96{+-}0.34 vs 2.27{+-}0.20, %WR; 24.71{+-}16.99% vs 12.89{+-}11.94). The diabetic patients with hypertension had higher morbidity with diabetic retinopathy and a lower H/M ratio. The 17 patients who developed hypertension during the observation period showed an increase in %WR and a reduction in the H/M ratio. Five patients who died during the observation period had a reduced H/M ratio and increased of %WR. {sup 123}I-MIBG myocardial scintigraphy in diabetic patients was shown to be useful for detecting cardiac sympathetic nervous system dysfunction, predicting the development of hypertension, and identifying patients who had a poor outcome. Diabetic patients with abnormal signals on MIBG myocardial scintigraphy need to be monitored much more carefully. (K.H.)

  2. Activation of NTS A2a adenosine receptors differentially resets baroreflex control of renal vs. adrenal sympathetic nerve activity.

    Science.gov (United States)

    Ichinose, Tomoko K; O'Leary, Donal S; Scislo, Tadeusz J

    2009-04-01

    The role of nucleus of solitary tract (NTS) A(2a) adenosine receptors in baroreflex mechanisms is controversial. Stimulation of these receptors releases glutamate within the NTS and elicits baroreflex-like decreases in mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA), whereas inhibition of these receptors attenuates HR baroreflex responses. In contrast, stimulation of NTS A(2a) adenosine receptors increases preganglionic adrenal sympathetic nerve activity (pre-ASNA), and the depressor and sympathoinhibitory responses are not markedly affected by sinoaortic denervation and blockade of NTS glutamatergic transmission. To elucidate the role of NTS A(2a) adenosine receptors in baroreflex function, we compared full baroreflex stimulus-response curves for HR, RSNA, and pre-ASNA (intravenous nitroprusside/phenylephrine) before and after bilateral NTS microinjections of selective adenosine A(2a) receptor agonist (CGS-21680; 2.0, 20 pmol/50 nl), selective A(2a) receptor antagonist (ZM-241385; 40 pmol/100 nl), and nonselective A(1) + A(2a) receptor antagonist (8-SPT; 1 nmol/100 nl) in urethane/alpha-chloralose anesthetized rats. Activation of A(2a) receptors decreased the range, upper plateau, and gain of baroreflex-response curves for RSNA, whereas these parameters all increased for pre-ASNA, consistent with direct effects of the agonist on regional sympathetic activity. However, no resetting of baroreflex-response curves along the MAP axis occurred despite the marked decreases in baseline MAP. The antagonists had no marked effects on baseline variables or baroreflex-response functions. We conclude that the activation of NTS A(2a) adenosine receptors differentially alters baroreflex control of HR, RSNA, and pre-ASNA mostly via non-baroreflex mechanism(s), and these receptors have virtually no tonic action on baroreflex control of these sympathetic outputs.

  3. Relationships between salt sensitivity of blood pressure and sympathetic nervous system activity: a short review of evidence.

    Science.gov (United States)

    Strazzullo, P; Barbato, A; Vuotto, P; Galletti, F

    2001-01-01

    Experimental and clinical studies provided evidence in favor of complex relationships between sympathetic nervous system activity and salt-sensitivity of blood pressure. Genetic and acquired metabolic alterations associated with a tendency to retain salt and water may generate salt-sensitivity of blood pressure and shift the pressure-natriuresis curve to the right, promoting an increase in blood pressure. Sympathetic activation is a factor contributing to this result. Chronic high dietary salt intake is followed by a derangement in mechanisms of central sympathetic inhibition and then by an enhanced peripheral sympathetic tone. This, in turn, may generate salt-sensitivity of blood pressure by affecting renal hemodynamics, tubular sodium and water handling. Insulin resistance and sodium and water retention are prompted by high-fat (as well as high carbohydrate) diets, and by an increase in body fat mass. Also, aging is a condition of impaired interactions of the above factors. A gain in weight due to reduced physical activity, not followed by a parallel decrease in calorie intake, brings to a fall in insulin sensitivity. In many cases, the natural age-related decline of renal function is associated with a reduced physical exercise, hyperinsulinemia and sodium retention; sympathetic nervous system activity is enhanced and causes an increase in blood pressure. PMID:11270585

  4. Augmented supraorbital skin sympathetic nerve activity responses to symptom trigger events in rosacea patients.

    Science.gov (United States)

    Metzler-Wilson, Kristen; Toma, Kumika; Sammons, Dawn L; Mann, Sarah; Jurovcik, Andrew J; Demidova, Olga; Wilson, Thad E

    2015-09-01

    Facial flushing in rosacea is often induced by trigger events. However, trigger causation mechanisms are currently unclear. This study tested the central hypothesis that rosacea causes sympathetic and axon reflex-mediated alterations resulting in trigger-induced symptomatology. Twenty rosacea patients and age/sex-matched controls participated in one or a combination of symptom triggering stressors. In protocol 1, forehead skin sympathetic nerve activity (SSNA; supraorbital microneurography) was measured during sympathoexcitatory mental (2-min serial subtraction of novel numbers) and physical (2-min isometric handgrip) stress. In protocol 2, forehead skin blood flow (laser-Doppler flowmetry) and transepithelial water loss/sweat rate (capacitance hygrometry) were measured during sympathoexcitatory heat stress (whole body heating by perfusing 50°C water through a tube-lined suit). In protocol 3, cheek, forehead, forearm, and palm skin blood flow were measured during nonpainful local heating to induce axon reflex vasodilation. Heart rate (HR) and mean arterial pressure (MAP) were recorded via finger photoplethysmography to calculate cutaneous vascular conductance (CVC; flux·100/MAP). Higher patient transepithelial water loss was observed (rosacea 0.20 ± 0.02 vs. control 0.10 ± 0.01 mg·cm(-2)·min(-1), P MAP changes were not different between groups during sympathoexcitatory stressors or local heating. SSNA during early mental (32 ± 9 and 9 ± 4% increase) and physical (25 ± 4 and 5 ± 1% increase, rosacea and controls, respectively) stress was augmented in rosacea (both P < 0.05). Heat stress induced more rapid sweating and cutaneous vasodilation onset in rosacea compared with controls. No axon reflex vasodilation differences were observed between groups. These data indicate that rosacea affects SSNA and that hyperresponsiveness to trigger events appears to have a sympathetic component. PMID:26133800

  5. Sympathetic reinnervation in cardiac transplants: {sup 123}I-MIBG and {sup 201}Tl/{sup 99m}Tc-MIBI scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. H.; Oh, S. J.; Son, M. S.; Son, J. W.; Choi, I. S.; Shin, E. K.; Park, C. H. [Gachon Medical School, Gil Heart Cener, Inchon (Korea, Republic of)

    2000-07-01

    The purpose was to evaluate cardiac sympathetic reinnervation and hemodynamic changes after orthotopic heart transplantation (TPL). We performed 24 serial or followup cardiac 123I-MIBG imaging and rest 201Tl/99mTc-MIBI dipyridamole stress gated myocardial perfusion SPECT (g-MPS) in 15 patients (M:F=10:5;mean ages=34.5{+-}13.0 yr; idiopathic:rheumatic=14:1; one heart lung TPL)(10.80 {+-}11.88 (1-48) mo) after TPL 123I-MIBG imagings were performed in anterior position 15 minutes, 4 and 24 hours after i.v. injection of 148 MBq 123I MIBG. Image quantitation was based on the ratio of heart to mediastinal MIBG uptake (HMR) Compared to HMR on 15 min images (1.48 {+-} 0.28), neither four nor 24 hour delayed images (1.26 {+-} 0.23 vs. 1.06 {+-} 0.26: p<0.05, respectively, ANOVA) showed definite delayed localization of MIBG. 12 subjects with <13 (4.9 {+-}3.7) months after TPL had no visible 123I-MIBG uptake on early 15 min imaging however, 12 subjects with 13 to 48(28.6{+-}12.8) months had visible cardiac 123I-MIBG uptake (HMR: 1.65{+-}0.21 vs. 1.32{+-}0.26; p=0.002). One-year followup 123I-MIBG scintigraphy in nine pts showed significantly increased HMR(1.40{+-}0.31 to 1.61{+-}0.16, p<0.05) but a plateau was reached at HMR value of 2.0, which was still lower than 3.0 in normal controls. Plasma NE was increased according to I-123 MIBG myocardial uptake. Annual G-MPS detected an allograft atherosclerosis in one pt and showed progressive normalization of tachycardia and significant deterioration of LVEF and cardiac indices according to severity of rejection. To dipyridamole stress, transplant heats showed significant subnormal hemodynamic responses. Partial sympathetic late reinnervation can occur <1 year after TPL, and reached a plateau of two-third of normal value. G-MPS seems to be a useful screening test for the detection of allograft atherosclerosis and rejection.

  6. Activation of NTS A1 adenosine receptors inhibits regional sympathetic responses evoked by activation of cardiopulmonary chemoreflex

    OpenAIRE

    Ichinose, Tomoko K.; Minic, Zeljka; Li, Cailian; O'Leary, Donal S.; Scislo, Tadeusz J.

    2012-01-01

    Previously we have shown that adenosine operating via the A1 receptor subtype may inhibit glutamatergic transmission in the baroreflex arc within the nucleus of the solitary tract (NTS) and differentially increase renal (RSNA), preganglionic adrenal (pre-ASNA), and lumbar (LSNA) sympathetic nerve activity (ASNA>RSNA≥LSNA). Since the cardiopulmonary chemoreflex and the arterial baroreflex are mediated via similar medullary pathways, and glutamate is a primary transmitter in both pathways, it i...

  7. Effects of lower body positive pressure on muscle sympathetic nerve activity response [correction of respopnse] to head-up tilt.

    Science.gov (United States)

    Fu, Q; Iwase, S; Niimi, Y; Kamiya, A; Kawanokuchi, J; Cui, J; Mano, T

    2001-07-01

    The benefits of lower body positive pressure (LBPP) are generally accepted for clinical treatment in medical emergencies caused by massive bleeding to maintain the systemic blood pressure. They are also used by NASA post spaceflight for preventing orthostatic hypotension in the astronauts. However, controversy still exists concerning the mechanisms underlying LBPP benefits. The purpose of this study was to test the hypothesis that the baroreflex-mediated enhancement in sympathetic activity would be attenuated by LBPP during an orthostatic challenge in humans. Specifically, we studied 1) the sympathetic activity responses by the microneurographic technique, using direct intraneural measurement of muscle sympathetic nerve activity (MSNA); and 2) the contributions of preload and afterload to the chances in MSNA response during orthostasis on application of LBPP. To accomplish these issues, MSNA was recorded microneurographically along with noninvasive measurement of the cardiovascular variables in all the subjects during exposure to a 70 degrees HUT with 30-mm Hg LBPP.

  8. Neuropeptide Y level in paraventricular nucleus of experimental diabetic rats: correlation with sympathetic activity and body weight

    Directory of Open Access Journals (Sweden)

    Pallab K Ganguly

    2010-09-01

    Full Text Available Pallab K GangulyCollege of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi ArabiaAbstract: Neuropeptide Y (NPY, colocalized with norepinephrine neuron, is known to modulate sympathetic activity and feeding behavior. Although experimental type 1 diabetes has increased sympathetic activity at the early part of the disease process, little effort was made so far to understand the correlation between NPY level in the hypothalamus and sympathetic activity in diabetes. Male Sprague Dawley rats were made diabetic by a single injection of streptozotocin (65 mg/kg body weight, IV. The animals were then studied after 2, 4, and 8 weeks. Control animals received only citrate vehicle. In an effort to clarify the modulatory effect of NPY at the early stage of diabetes, the paraventricular nucleus (PVN of hypothalamus was sampled by microdialysis for NPY and norepinephrine level. While NPY level was increased immediately within 2 weeks (along with feeding behavior, norepinephrine level was increased only after 8 weeks following injection of streptozotocin. The animals lost significant weight. These results are interpreted to mean that a strong correlation exists between the feeding behavior and NPY level in PVN. Since NPY is known to inhibit sympathetic activity it is possible that NPY receptors are down-regulated following diabetes. The higher level of norepinephrine indicating higher sympathetic activity did not allow the animals to gain weight. In addition, controversy exists regarding pleiotropic activities of NPY related to the feeding behavior of these animals.Keywords: streptozotocin-induced diabetes, increased sympathetic activity, feeding behavior, down-regulation of NPY receptors

  9. Sympathetic activation in exercise is not dependent on muscle acidosis. Direct evidence from studies in metabolic myopathies

    Science.gov (United States)

    Vissing, J.; Vissing, S. F.; MacLean, D. A.; Saltin, B.; Quistorff, B.; Haller, R. G.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    Muscle acidosis has been implicated as a major determinant of reflex sympathetic activation during exercise. To test this hypothesis we studied sympathetic exercise responses in metabolic myopathies in which muscle acidosis is impaired or augmented during exercise. As an index of reflex sympathetic activation to muscle, microneurographic measurements of muscle sympathetic nerve activity (MSNA) were obtained from the peroneal nerve. MSNA was measured during static handgrip exercise at 30% of maximal voluntary contraction force to exhaustion in patients in whom exercise-induced muscle acidosis is absent (seven myophosphorylase deficient patients; MD [McArdle's disease], and one patient with muscle phosphofructokinase deficiency [PFKD]), augmented (one patient with mitochondrial myopathy [MM]), or normal (five healthy controls). Muscle pH was monitored by 31P-magnetic resonance spectroscopy during handgrip exercise in the five control subjects, four MD patients, and the MM and PFKD patients. With handgrip to exhaustion, the increase in MSNA over baseline (bursts per minute [bpm] and total activity [%]) was not impaired in patients with MD (17+/-2 bpm, 124+/-42%) or PFKD (65 bpm, 307%), and was not enhanced in the MM patient (24 bpm, 131%) compared with controls (17+/-4 bpm, 115+/-17%). Post-handgrip ischemia studied in one McArdle patient, caused sustained elevation of MSNA above basal suggesting a chemoreflex activation of MSNA. Handgrip exercise elicited an enhanced drop in muscle pH of 0.51 U in the MM patient compared with the decrease in controls of 0.13+/-0.02 U. In contrast, muscle pH increased with exercise in MD by 0.12+/-0.05 U and in PFKD by 0.01 U. In conclusion, patients with glycogenolytic, glycolytic, and oxidative phosphorylation defects show normal muscle sympathetic nerve responses to static exercise. These findings indicate that muscle acidosis is not a prerequisite for sympathetic activation in exercise.

  10. Sympathetic activity-mediated neuropathic facial pain following simple tooth extraction: a case report.

    Science.gov (United States)

    Kohjitani, Atsushi; Miyawaki, Takuya; Kasuya, Keigo; Shimada, Masahiko

    2002-04-01

    This is a report of a case of sympathetic activity-mediated neuropathic facial pain induced by a traumatic trigeminal nerve injury and by varicella zoster virus infection, following a simple tooth extraction. The patient had undergone extraction of the right lower third molar at a local dental clinic, and soon after the tooth extraction, she became aware of spontaneous pain in the right ear, right temporal region, and in the tooth socket. At our initial examination 30 days after the tooth extraction, the healing of the tooth socket was normal; however, the patient had a tingling and burning sensation (dysesthesia) and spontaneous pain of the right lower lip and the right temporal region, both of which were exacerbated by non-noxious stimuli (allodynia). The patient also showed paralysis of the marginal mandibular branch of the facial nerve, taste dysfunction, and increased varicella zoster serum titers. A diagnostic stellate ganglion block (SGB) 45 days after the tooth extraction using one percent lidocaine markedly alleviated the dysesthesia and allodynia. These symptoms are characteristic of neuropathic pain with sympathetic interaction. The patient was successfully treated with SGB and a tricyclic antidepressant. PMID:12002830

  11. Strength training reduces arterial blood pressure but not sympathetic neural activity in young normotensive subjects

    Science.gov (United States)

    Carter, Jason R.; Ray, Chester A.; Downs, Emily M.; Cooke, William H.

    2003-01-01

    The effects of resistance training on arterial blood pressure and muscle sympathetic nerve activity (MSNA) at rest have not been established. Although endurance training is commonly recommended to lower arterial blood pressure, it is not known whether similar adaptations occur with resistance training. Therefore, we tested the hypothesis that whole body resistance training reduces arterial blood pressure at rest, with concomitant reductions in MSNA. Twelve young [21 +/- 0.3 (SE) yr] subjects underwent a program of whole body resistance training 3 days/wk for 8 wk. Resting arterial blood pressure (n = 12; automated sphygmomanometer) and MSNA (n = 8; peroneal nerve microneurography) were measured during a 5-min period of supine rest before and after exercise training. Thirteen additional young (21 +/- 0.8 yr) subjects served as controls. Resistance training significantly increased one-repetition maximum values in all trained muscle groups (P training did not affect MSNA or heart rate. Arterial blood pressures and MSNA were unchanged, but heart rate increased after 8 wk of relative inactivity for subjects in the control group (61 +/- 2 to 67 +/- 3 beats/min; P = 0.01). These results indicate that whole body resistance exercise training might decrease the risk for development of cardiovascular disease by lowering arterial blood pressure but that reductions of pressure are not coupled to resistance exercise-induced decreases of sympathetic tone.

  12. Frontal midline theta rhythm is correlated with cardiac autonomic activities during the performance of an attention demanding meditation procedure.

    Science.gov (United States)

    Kubota, Y; Sato, W; Toichi, M; Murai, T; Okada, T; Hayashi, A; Sengoku, A

    2001-04-01

    Frontal midline theta rhythm (Fm theta), recognized as distinct theta activity on EEG in the frontal midline area, reflects mental concentration as well as meditative state or relief from anxiety. Attentional network in anterior frontal lobes including anterior cingulate cortex is suspected to be the generator of this activity, and the regulative function of the frontal neural network over autonomic nervous system (ANS) during cognitive process is suggested. However no studies have examined peripheral autonomic activities during Fm theta induction, and interaction of central and peripheral mechanism associated with Fm theta remains unclear. In the present study, a standard procedure of Zen meditation requiring sustained attention and breath control was employed as the task to provoke Fm theta, and simultaneous EEG and ECG recordings were performed. For the subjects in which Fm theta activities were provoked (six men, six women, 48% of the total subjects), peripheral autonomic activities were evaluated during the appearance of Fm theta as well as during control periods. Successive inter-beat intervals were measured from the ECG, and a recently developed method of analysis by Toichi et al. (J. Auton. Nerv. Syst. 62 (1997) 79-84) based on heart rate variability was used to assess cardiac sympathetic and parasympathetic functions separately. Both sympathetic and parasympathetic indices were increased during the appearance of Fm theta compared with control periods. Theta band activities in the frontal area were correlated negatively with sympathetic activation. The results suggest a close relationship between cardiac autonomic function and activity of medial frontal neural circuitry.

  13. Alzheimer caregiver stress: basal natural killer cell activity, pituitary-adrenal cortical function, and sympathetic tone.

    Science.gov (United States)

    Irwin, M; Hauger, R; Patterson, T L; Semple, S; Ziegler, M; Grant, I

    1997-01-01

    The association between Alzheimer caregiving and natural killer (NK) cell activity and basal plasma levels of adrenocorticotropic hormone (ACTH), cortisol, beta-endorphin, prolactin, epinephrine, norepinephrine, and neuropeptide Y was determined in 100 spousal Alzheimer caregivers and 33 age- and gender-comparable control volunteers upon intake into a study of the psychological and physiologic impact of caregiving. The relationship between these physiologic measures and individual characteristics such as age, gender, medical status, severity of stress, severity of depressive symptoms, and caregiver burden was tested. In addition, the association between NK activity and alterations of the neuroendocrine measures was investigated. As compared to controls, the Alzheimer caregivers had similar levels of NK activity and of basal plasma neuroendocrine hormones and sympathetic measures. While older age and male gender status were associated with increased levels of ACTH, neither medical caseness, severity of life stress, nor severity of depressive symptoms was associated with alterations in any of the multiple physiologic domains. Classification of Alzheimer caregiver burden identified caregivers who were mismatched in terms of the amount of care they were required to provide and the amount of respite time received. The mismatched caregivers had significantly higher basal plasma ACTH but no change in other physiological measures, as compared to non-mismatched caregivers. NK activity was negatively correlated with plasma levels of neuropeptide Y but not with any of the other neuroendocrine measures. Based on this cross-sectional evaluation of NK activity and neuroendocrine and sympathetic measures, we conclude that most Alzheimer caregivers do not show evidence of altered basal physiology.

  14. Catheter Ablation of Atrial Fibrillation Raises the Plasma Level of NGF-β Which Is Associated with Sympathetic Nerve Activity

    OpenAIRE

    Park, Jae Hyung; Hong, Sung Yu; Wi, Jin; Lee, Da Lyung; Joung, Boyoung; Lee, Moon Hyoung; Pak, Hui-Nam

    2015-01-01

    Purpose The expression of nerve growth factor-β (NGF-β) is related to cardiac nerve sprouting and sympathetic hyper innervation. We investigated the changes of plasma levels of NGF-β and the relationship to follow-up heart rate variability (HRV) after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Materials and Methods This study included 147 patients with AF (117 men, 55.8±11.5 years, 106 paroxysmal AF) who underwent RFCA. The plasma levels of NGF-β were quantified usin...

  15. Perfusion of isolated carotid sinus with hydrogen sulfide attenuated the renal sympathetic nerve activity in anesthetized male rats.

    Science.gov (United States)

    Guo, Q; Wu, Y; Xue, H; Xiao, L; Jin, S; Wang, R

    2016-07-18

    The purpose of the present study was to define the indirect central effect of hydrogen sulfide (H(2)S) on baroreflex control of sympathetic outflow. Perfusing the isolated carotid sinus with sodium hydrosulfide (NaHS), a H(2)S donor, the effect of H(2)S was measured by recording changes of renal sympathetic nerve activity (RSNA) in anesthetized male rats. Perfusion of isolated carotid sinus with NaHS (25, 50, 100 micromol/l) dose and time-dependently inhibited sympathetic outflow. Preconditioning of glibenclamide (20 micromol/l), a ATP-sensitive K(+) channels (K(ATP)) blocker, the above effect of NaHS was removed. With 1, 4-dihydro-2, 6-dimethyl-5-nitro-4-(2-[trifluoromethyl] phenyl) pyridine-3-carboxylic acid methyl ester (Bay K8644, 500 nmol/l) pretreatment, which is an agonist of L-calcium channels, the effect of NaHS was eliminated. Perfusion of cystathionine gamma-lyase (CSE) inhibitor, DL-propargylglycine (PPG, 200 micromol/l), increased sympathetic outflow. The results show that exogenous H(2)S in the carotid sinus inhibits sympathetic outflow. The effect of H(2)S is attributed to opening K(ATP) channels and closing the L-calcium channels.

  16. Perfusion of isolated carotid sinus with hydrogen sulfide attenuated the renal sympathetic nerve activity in anesthetized male rats.

    Science.gov (United States)

    Guo, Q; Wu, Y; Xue, H; Xiao, L; Jin, S; Wang, R

    2016-07-18

    The purpose of the present study was to define the indirect central effect of hydrogen sulfide (H(2)S) on baroreflex control of sympathetic outflow. Perfusing the isolated carotid sinus with sodium hydrosulfide (NaHS), a H(2)S donor, the effect of H(2)S was measured by recording changes of renal sympathetic nerve activity (RSNA) in anesthetized male rats. Perfusion of isolated carotid sinus with NaHS (25, 50, 100 micromol/l) dose and time-dependently inhibited sympathetic outflow. Preconditioning of glibenclamide (20 micromol/l), a ATP-sensitive K(+) channels (K(ATP)) blocker, the above effect of NaHS was removed. With 1, 4-dihydro-2, 6-dimethyl-5-nitro-4-(2-[trifluoromethyl] phenyl) pyridine-3-carboxylic acid methyl ester (Bay K8644, 500 nmol/l) pretreatment, which is an agonist of L-calcium channels, the effect of NaHS was eliminated. Perfusion of cystathionine gamma-lyase (CSE) inhibitor, DL-propargylglycine (PPG, 200 micromol/l), increased sympathetic outflow. The results show that exogenous H(2)S in the carotid sinus inhibits sympathetic outflow. The effect of H(2)S is attributed to opening K(ATP) channels and closing the L-calcium channels. PMID:26988151

  17. Clinical relationship of myocardial sympathetic nervous activity to cardiovascular functions in chronic heart failure: assessment by myocardial scintigraphy with 123I-metaiodobenzylguanidine.

    Science.gov (United States)

    Wada, Yukoh; Miura, Masaetsu; Fujiwara, Satomi; Mori, Shunpei; Seiji, Kazumasa; Kimura, Tokihisa

    2003-12-01

    The aim of this study was to clarify the relationship between cardiac sympathetic nervous activity (SNA) assessed by radioiodinated metaiodobenzylguanidine (123I-MIBG), an analogue of norepinephrine and cardiovascular functions in patients with chronic heart failure (CHF). Subjects were 17 patients with CHF. A dose of 111 MBq of 123I-MIBG was administered intravenously, and 5-minute anterior planar images were obtained 15 minutes (early image) and 3 hours (delayed image) after the injection. The heart/mediastinum (H/M) count ratio was defined to quantify cardiac 123I-MIBG uptake. The washout ratio (WR) of 123I-MIBG from the heart was calculated as follows: (early counts-delayed counts)/early counts x 100 (%). Echocardiography was performed on all patients within 1 week of 123I-MIBG scintigraphy to measure stroke volume index (SVI). Blood pressure and heart rate (HR) in the resting state were also recorded to calculate cardiovascular functions including cardiac output, pulse pressure (PP), and mean blood pressure. Significant linear correlations were found between the early H/M ratio of 123I-MIBG and SVI, and between the delayed H/M ratio of 123I-MIBG and SVI, respectively. WR of 123I-MIBG was correlated with HR, and was inversely correlated with SVI and with PP, respectively. It is likely that a decrease in SVI is associated with enhanced cardiac SNA in severe CHF. 123I-MIBG scintigraphy is effective in assessing the cardiac functional status and SNA in patients with CHF in vivo. Moreover, changes in PP and HR indicate well alteration in SNA. PMID:14690018

  18. Sensing Cardiac Electrical Activity With a Cardiac Myocyte--Targeted Optogenetic Voltage Indicator

    NARCIS (Netherlands)

    Chang Liao, Mei-Ling; de Boer, Teun P; Mutoh, Hiroki; Raad, Nour; Richter, Claudia; Wagner, Eva; Downie, Bryan R; Unsöld, Bernhard; Arooj, Iqra; Streckfuss-Bömeke, Katrin; Döker, Stephan; Luther, Stefan; Guan, Kaomei; Wagner, Stefan; Lehnart, Stephan E; Maier, Lars S; Stühmer, Walter; Wettwer, Erich; van Veen, Toon; Morlock, Michael M; Knöpfel, Thomas; Zimmermann, Wolfram-Hubertus

    2015-01-01

    RATIONALE: Monitoring and controlling cardiac myocyte activity with optogenetic tools offer exciting possibilities for fundamental and translational cardiovascular research. Genetically encoded voltage indicators may be particularly attractive for minimal invasive and repeated assessments of cardiac

  19. Coping with dehydration: sympathetic activation and regulation of glutamatergic transmission in the hypothalamic PVN.

    Science.gov (United States)

    Bardgett, Megan E; Chen, Qing-Hui; Guo, Qing; Calderon, Alfredo S; Andrade, Mary Ann; Toney, Glenn M

    2014-06-01

    Autonomic and endocrine profiles of chronic hypertension and heart failure resemble those of acute dehydration. Importantly, all of these conditions are associated with exaggerated sympathetic nerve activity (SNA) driven by glutamatergic activation of the hypothalamic paraventricular nucleus (PVN). Here, studies sought to gain insight into mechanisms of disease by determining the role of PVN ionotropic glutamate receptors in supporting SNA and mean arterial pressure (MAP) during dehydration and by elucidating mechanisms regulating receptor activity. Blockade of PVN N-methyl-D-aspartate (NMDA) receptors reduced (P chloralose-anesthetized dehydrated (DH) (48 h water deprivation) rats, but had no effect in euhydrated (EH) controls. Blockade of PVN α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors had no effect in either group. NMDA in PVN caused dose-dependent increases of renal SNA and MAP in both groups, but the maximum agonist evoked response (Emax) of the renal SNA response was greater (P < 0.05) in DH rats. The latter was not explained by increased PVN expression of NMDA receptor NR1 subunit protein, increased PVN neuronal excitability, or decreased brain water content. Interestingly, PVN injection of the pan-specific excitatory amino acid transporter (EAAT) inhibitor DL-threo-β-benzyloxyaspartic acid produced smaller sympathoexcitatory and pressor responses in DH rats, which was associated with reduced glial expression of EAAT2 in PVN. Like chronic hypertension and heart failure, dehydration increases excitatory NMDA receptor tone in PVN. Reduced glial-mediated glutamate uptake was identified as a key contributing factor. Defective glutamate uptake in PVN could therefore be an important, but as yet unexplored, mechanism driving sympathetic hyperactivity in chronic cardiovascular diseases. PMID:24671240

  20. Use of iodine-123 metaiodobenzylguanidine scintigraphy to assess cardiac sympathetic denervation and the impact of hypertension in patients with non-insulin-dependent diabetes mellitus

    International Nuclear Information System (INIS)

    The objectives of this clinical study using iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy were (a) to evaluate cardiac sympathetic denervation in non-insulin-dependent diabetes mellitus (NIDDM) patients with and without hypertension and (b) to investigate the relation between cardiac sympathetic denervation and prognosis in NIDDM patients. We compared clinical characteristics and MIBG data [heart to mediastinum (H/M) ratio and % washout rate (WR)] in a control group and NIDDM patients with and without hypertension. MIBG scintigraphy was performed in 11 controls and 82 NIDDM patients without overt cardiovascular disease except for hypertension (systolic blood pressure ≥140 and/or diastolic blood pressure ≥90 mmHg). After MIBG examination, blood pressure was measured regularly in all NIDDM patients. There were significant differences between 65 normotensive and 17 hypertensive NIDDM patients with respect to age (55±11 vs 63±12 years, respectively, P<0.05), prevalence of diabetic retinopathy (12% vs 35%, respectively, P<0.05) and systolic blood pressure (120±12 vs 145±16 mmHg, respectively, P<0.001). The H/M ratio in hypertensive NIDDM patients was significantly lower than in the control group (1.81±0.29 vs 2.27±0.20, respectively, P<0.01). During the follow-up period (18± 12 months), 17 NIDDM patients newly developed hypertension after MIBG examination. There were no significant differences in their clinical characteristics compared with persistently normotensive or hypertensive NIDDM patients. %WR in patients with new onset hypertension was significantly higher than in the control group (30.88%±16.87% vs 12.89%±11.94%, respectively, P<0.05). Moreover, in these patients %WR correlated with duration from the date of MIBG scintigraphy to the onset of hypertension (r=-0.512, P<0.05). Five NIDDM patients died during the follow-up period (four newly hypertensive patients and one normotensive patient). There were significant statistical differences

  1. Activation of NTS A(1) adenosine receptors inhibits regional sympathetic responses evoked by activation of cardiopulmonary chemoreflex.

    Science.gov (United States)

    Ichinose, Tomoko K; Minic, Zeljka; Li, Cailian; O'Leary, Donal S; Scislo, Tadeusz J

    2012-09-01

    Previously we have shown that adenosine operating via the A(1) receptor subtype may inhibit glutamatergic transmission in the baroreflex arc within the nucleus of the solitary tract (NTS) and differentially increase renal (RSNA), preganglionic adrenal (pre-ASNA), and lumbar (LSNA) sympathetic nerve activity (ASNA>RSNA≥LSNA). Since the cardiopulmonary chemoreflex and the arterial baroreflex are mediated via similar medullary pathways, and glutamate is a primary transmitter in both pathways, it is likely that adenosine operating via A(1) receptors in the NTS may differentially inhibit regional sympathetic responses evoked by activation of cardiopulmonary chemoreceptors. Therefore, in urethane-chloralose-anesthetized rats (n = 37) we compared regional sympathoinhibition evoked by the cardiopulmonary chemoreflex (activated with right atrial injections of serotonin 5HT(3) receptor agonist phenylbiguanide, PBG, 1-8 μg/kg) before and after selective stimulation of NTS A(1) adenosine receptors [microinjections of N(6)-cyclopentyl adenosine (CPA), 0.033-330 pmol/50 nl]. Activation of cardiopulmonary chemoreceptors evoked differential, dose-dependent sympathoinhibition (RSNA>ASNA>LSNA), and decreases in arterial pressure and heart rate. These differential sympathetic responses were uniformly attenuated in dose-dependent manner by microinjections of CPA into the NTS. Volume control (n = 11) and blockade of adenosine receptor subtypes in the NTS via 8-(p-sulfophenyl)theophylline (8-SPT, 1 nmol in 100 nl) (n = 9) did not affect the reflex responses. We conclude that activation of NTS A(1) adenosine receptors uniformly inhibits neural and cardiovascular cardiopulmonary chemoreflex responses. A(1) adenosine receptors have no tonic modulatory effect on this reflex under normal conditions. However, when adenosine is released into the NTS (i.e., during stress or severe hypotension/ischemia), it may serve as negative feedback regulator for depressor and sympathoinhibitory reflexes

  2. Effects of acute administration of selective serotonin reuptake inhibitors on sympathetic nerve activity

    Energy Technology Data Exchange (ETDEWEB)

    Tiradentes, R.V. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Centro Universitário do Espírito Santo, Colatina, ES (Brazil); Pires, J.G.P. [Centro Universitário do Espírito Santo, Colatina, ES (Brazil); Escola de Medicina da Empresa Brasileira de Ensino, Vitória, ES (Brazil); Silva, N.F. [Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Ramage, A.G. [Department of Neuroscience, Physiology and Pharmacology, University College London, London (United Kingdom); Santuzzi, C.H. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Centro Universitário do Espírito Santo, Colatina, ES (Brazil); Futuro, H.A. Neto [Escola de Medicina da Empresa Brasileira de Ensino, Vitória, ES (Brazil); Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Escola Superior de Ciências da Saúde, Santa Casa de Misericórdia de Vitória, Vitória, ES (Brazil)

    2014-05-30

    Serotonergic mechanisms have an important function in the central control of circulation. Here, the acute effects of three selective serotonin (5-HT) reuptake inhibitors (SSRIs) on autonomic and cardiorespiratory variables were measured in rats. Although SSRIs require 2-3 weeks to achieve their full antidepressant effects, it has been shown that they cause an immediate inhibition of 5-HT reuptake. Seventy male Wistar rats were anesthetized with urethane and instrumented to record blood pressure, heart rate, renal sympathetic nerve activity (RSNA), and respiratory frequency. At lower doses, the acute cardiovascular effects of fluoxetine, paroxetine and sertraline administered intravenously were insignificant and variable. At middle and higher doses, a general pattern was observed, with significant reductions in sympathetic nerve activity. At 10 min, fluoxetine (3 and 10 mg/kg) reduced RSNA by -33±4.7 and -31±5.4%, respectively, without changes in blood pressure; 3 and 10 mg/kg paroxetine reduced RSNA by -35±5.4 and -31±5.5%, respectively, with an increase in blood pressure +26.3±2.5; 3 mg/kg sertraline reduced RSNA by -59.4±8.6%, without changes in blood pressure. Sympathoinhibition began 5 min after injection and lasted approximately 30 min. For fluoxetine and sertraline, but not paroxetine, there was a reduction in heart rate that was nearly parallel to the sympathoinhibition. The effect of these drugs on the other variables was insignificant. In conclusion, acute peripheral administration of SSRIs caused early autonomic cardiovascular effects, particularly sympathoinhibition, as measured by RSNA. Although a peripheral action cannot be ruled out, such effects are presumably mostly central.

  3. Sympathetic reinnervation in cardiac transplants : preliminary results {sup 123}I-MIBG and {sup 201}Tl/{sup 99m}Tc-MIBI scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joug Ho; Oh, Se Jin; Son, Min Soo; Son, Ji Won; Choi, In Seok; Shin, Euk Kyun; Park, Kuk Yang; Kim, Ju E. [International Medicine and Thoraic Surgery, Inchon (Korea, Republic of)

    1997-07-01

    Iodine-123 metaiodobenzylguanidine ({sup 123}I-MIBG) is a norepinephrine (NE) analogue. To determine whether cardiac sympathetic reinnervation occurs after orthotopic heart transplantation (TPL). Nine patients (M : F=7 :2; mean ages=34{+-}24.1 yr; idiopathic:rheumatic = 8: 1) within 197.{+-}14.3 (4-36) months after TPL performed both {sup 123}I-MIBG scintigraphy and {sup 201}Tl/{sup 99m}Tc-MIBI dipyridamole stress gated myocardial perfusion SPECT (g-MPS). {sup 23}I-MIBG imagings were performed in anterior position 15 minutes, 4 and 24 hours after i.v. injection of 148 MBq {sup 123}I MIBG. Image quantitation was based on the ratio of hear to mediastinal MIBG uptake (HMR). Six subjects with <14 (4.3{+-}1.4) months after TPL had no visible {sup 123}I-MIBG uptake on early 15. min imaging however, three subjects with 26 to 36(32.0{+-}5.3) months had visible cardiac {sup 123}I-MIBG uptake (HMR:1.24{+-}0.09 vs. 1.8{+-}0.2). Correlation was found between plasma NE concentration and HMR(r=0.80: p<0.05). Compared to HMR on 15 min images (1.5{+-}0.3), neither four nor 24 hour delayed images (1.3{+-}0.3 vs. 1.1{+-}0.1 : p<0.05, respectively, ANOVA) showed definite delayed localization of MIBG. The uptakes in the liver, lung, salivary glands and spleen were present. To dipyridamole stress, transplant hearts showed significant subnormal hemodynamic responses of HR, s-BP, d-BP, and rate pressure product (95.4{+-}13.8 to 107.4{+-}14.6, 131.0{+-}16.7 to 123.6{+-}13.4, 79.1{+-}12.7 to 72.2{+-}12.7, 124.5{+-}19.6 to 133.0{+-}23.6 p<0.05, respectively). G-MPS of one patient shod an apicoanterior wall reversible perfusion defect which was confirmed as 90% distal left anterior descending artery stenosis by coronary angiography. MIBG uptake seems to involve mainly the specific sodium and energy dependent uptake-1 pathway, and the non-neuronal uptake-2 involving simple diffusion is not significant. Conclusively, partial sympathetic late reinnervation of the transplant human hearts can

  4. Recent evidence for activity-dependent initiation of sympathetic sprouting and neuropathic pain

    Institute of Scientific and Technical Information of China (English)

    Jun-Ming ZHANG; Judith A. Strong

    2008-01-01

    Traumatic injury or inflammatory irritation of the peripheral nervous system often leads to persistent pathophysiological pain states. It has been well-documented that, after peripheral nerve injury or inflammation, functional and anatomical alterations sweep over the entire peripheral nervous system including the peripheral nerve endings, the injured or inflamed afferent fibers, the dorsal root ganglion (DRG), and the central afferent terminals in the spinal cord. Among all the changes, ectopic discharge or spontaneous activity of primary sensory neurons is of great clinical interest, as such discharges doubtless contribute to the develop-ment of pathological pain states such as neuropathic pain. Two key sources of abnormal spontaneous activity have been identified following peripheral nerve injury: the injured afferent fibers (neuroma) leading to the DRG, and the DRG somata. The purpose of this review is to provide a global account of the abnormal spontaneous activity in various animal models of pain. Particular attention is focused on the consequence of peripheral nerve injury and localized inflammation. Further, mechanisms involved in the generation of spontaneous activity are also reviewed; evidence of spontaneous activity in contributing to abnormal sympathetic sprouting in the axotomized DRG and to the initiation of neuropathic pain based on new findings from our research group are discussed. An improved understanding of the causes of spontaneous activity and the origins of neuropathic pain should facilitate the development of novel strategies for effective treatment of pathological pain.

  5. Mean 24-hours sympathetic nervous system activity decreases during head-down tilted bed rest but not during microgravity

    Science.gov (United States)

    Christensen, Nj; Heer, M.; Ivanova, K.; Norsk, P.

    Sympathetic nervous system activity is closely related to gravitational stress in ground based experiments. Thus a high activity is present in the standing-up position and a very low activity is observed during acute head-out water immersion. Adjustments in sympathetic activity are necessary to maintain a constant blood pressure during variations in venous return. Head-down tilted bed rest is applied as a model to simulate changes observed during microgravity. The aim of the present study was to test the hypothesis that mean 24-hours sympathetic activity was low and similar during space flight and in ground based observation obtained during long-term head-down tilted bed rest. Forearm venous plasma noradrenaline was measured by a radioenzymatic technique as an index of muscle sympathetic activity and thrombocyte noradrenaline and adrenaline were measured as indices of mean 24-hours sympathoadrenal activity. Previous results have indicated that thrombocyte noradrenaline level has a half-time of 2 days. Thus to reflect sympathetic activity during a specific experiment the study period must last for at least 6 days and a sample must be obtained within 12 hours after the experiment has ended. Ten normal healthy subjects were studied before and during a 14 days head-down tilted bed rest as well as during an ambulatory study period of a similar length. The whole experiment was repeated while the subjects were on a low calorie diet. Thrombocyte noradrenaline levels were studied in 4 cosmonauts before and within 12 hours after landing after more than 7 days in flight. Thrombocyte noradrenaline decreased markedly during the head-down tilted bed rest (pnoradrenaline decreased in the adaptation period but not during the intervention. During microgravity thrombocyte noradrenaline increased in four cosmonauts and the percentage changes were significantly different in cosmonauts and in subjects participating in the head down tilted bed rest study (170± 29% (Mean± SEM) vs. 57

  6. Cardiac allograft immune activation: current perspectives

    OpenAIRE

    Chang D; Kobashigawa J

    2014-01-01

    David Chang, Jon Kobashigawa Cedars-Sinai Heart Institute, Los Angeles, CA, USA Abstract: Heart transplant remains the most durable option for end-stage heart disease. Cardiac allograft immune activation and heart transplant rejection remain among the main complications limiting graft and recipient survival. Mediators of the immune system can cause different forms of rejection post-heart transplant. Types of heart transplant rejection include hyperacute rejection, cellular rejection, antibod...

  7. Vibration sense and sympathetic vasoconstrictor activity in patients with occlusive arterial disease

    DEFF Research Database (Denmark)

    Bjerre-Jepsen, K; Henriksen, O; Parm, Martin Lehnsbo;

    1983-01-01

    function was studied by the capability of the local sympathetic venoarteriolar reflex (Henriksen 1977) elicited by lowering the leg to induce an arteriolar constriction in subcutaneous tissue at the ankle level. Blood flow was measured by the local isotope washout technique. In only five patients with loss...... of sympathetic vasoconstrictor function. It is suggested that this is studied by a simple postural test as used in the present study....

  8. Neural and sympathetic activity associated with exploration in decision-making: Further evidence for involvement of insula

    Directory of Open Access Journals (Sweden)

    Hideki eOhira

    2014-11-01

    Full Text Available We previously reported that sympathetic activity was associated with exploration in decision-making indexed by entropy, which is a concept in information theory and indexes randomness of choices or the degree of deviation from sticking to recent experiences of gains and losses, and that activation of the anterior insula mediated this association. The current study aims to replicate and to expand these findings in a situation where contingency between options and outcomes is manipulated. Sixteen participants performed a stochastic decision-making task in which we manipulated a condition with low uncertainty of gain/loss (contingent-reward condition and a condition with high uncertainty of gain/loss (random-reward condition. Regional cerebral blood flow was measured by 15O-water positron emission tomography (PET, and cardiovascular parameters and catecholamine in the peripheral blood were measured, during the task. In the contingent-reward condition, norepinephrine as an index of sympathetic activity was positively correlated with entropy indicating exploration in decision-making. Norepinephrine was negatively correlated with neural activity in the right posterior insula, rostral anterior cingulate cortex, and dorsal pons, suggesting neural bases for detecting changes of bodily states. Furthermore, right anterior insular activity was negatively correlated with entropy, suggesting influences on exploration in decision-making. By contrast, in the random-reward condition, entropy correlated with activity in the dorsolateral prefrontal and parietal cortices but not with sympathetic activity. These findings suggest that influences of sympathetic activity on exploration in decision-making and its underlying neural mechanisms might be dependent on the degree of uncertainty of situations.

  9. Reflex control of rat tail sympathetic nerve activity by abdominal temperature

    Science.gov (United States)

    Shafton, Anthony D; Kitchener, Peter; McKinley, Michael J; McAllen, Robin M

    2014-01-01

    The thermoregulatory reflex effects of warming and cooling in the abdomen were investigated in 4 urethane-anesthetized Sprague-Dawley rats. Animals were shaved and surrounded by a water-perfused silastic jacket. Skin temperature under the jacket was recorded by thermocouples at 3 sites and brain temperature was monitored by a thermocouple inserted lateral to the hypothalamus. A heat exchanger made from an array of silicon tubes in parallel loops was placed through a ventral incision into the abdomen; it rested against the intestinal serosa and the temperature of this interface was monitored by a thermocouple. Few- or multi-unit postganglionic activity was recorded from sympathetic nerves supplying tail vessels (tail SNA). Intra-abdominal temperature was briefly lowered or raised between 35–41 °C by perfusing the heat exchanger with cold or warm water. Warming the abdomen inhibited tail SNA while cooling it excited tail SNA in all 4 animals. We also confirmed that cooling the trunk skin activated tail SNA. Multivariate analysis of tail SNA with respect to abdominal, brain and trunk skin temperatures revealed that all had highly significant independent inhibitory actions on tail SNA, but in these experiments abdominal temperature had the weakest and brain temperature the strongest effect. We conclude that abdominal temperature has a significant thermoregulatory action in the rat, but its influence on cutaneous vasomotor control appears to be weaker than that of skin or brain temperatures.

  10. Leptin acts in the forebrain to differentially influence baroreflex control of lumbar, renal, and splanchnic sympathetic nerve activity and heart rate.

    Science.gov (United States)

    Li, Baoxin; Shi, Zhigang; Cassaglia, Priscila A; Brooks, Virginia L

    2013-04-01

    Although leptin is known to increase sympathetic nerve activity (SNA), we tested the hypothesis that leptin also enhances baroreflex control of SNA and heart rate (HR). Using α-chloralose anesthetized male rats, mean arterial pressure (MAP), HR, lumbar SNA (LSNA), splanchnic SNA (SSNA), and renal SNA (RSNA) were recorded before and for 2 hours after lateral cerebroventricular leptin or artificial cerebrospinal fluid administration. Baroreflex function was assessed using a 4-parameter sigmoidal fit of HR and SNA responses to slow ramp (3-5 minutes) changes in MAP, induced by intravenous infusion of nitroprusside and phenylephrine. Leptin (3 μg) increased (P<0.05) basal LSNA, SSNA, RSNA, HR, and MAP, and the LSNA, SSNA, RSNA, and HR baroreflex maxima. Leptin also increased gain of baroreflex control of LSNA and RSNA, but not of SSNA or HR. The elevations in HR were eliminated by pretreatment with methscopalamine, to block parasympathetic nerve activity; however, after cardiac sympathetic blockade with atenolol, leptin still increased basal HR and MAP and the HR baroreflex maximum and minimum. Leptin (1.5 μg) also increased LSNA and enhanced LSNA baroreflex gain and maximum, but did not alter MAP, HR, or the HR baroreflex. Lateral cerebroventricular artificial cerebrospinal fluid had no effects. Finally, to test whether leptin acts in the brain stem, leptin (3 μg) was infused into the 4th ventricle; however, no significant changes were observed. In conclusion, leptin acts in the forebrain to differentially influence baroreflex control of LSNA, RSNA, SSNA, and HR, with the latter action mediated via suppression of parasympathetic nerve activity. PMID:23424232

  11. Neck afferents and muscle sympathetic activity in humans: implications for the vestibulosympathetic reflex.

    Science.gov (United States)

    Ray, C A; Hume, K M

    1998-02-01

    We have shown previously that head-down neck flexion (HDNF) in humans elicits increases in muscle sympathetic nerve activity (MSNA). The purpose of this study was to determine the effect of neck muscle afferents on MSNA. We studied this question by measuring MSNA before and after head rotation that would activate neck muscle afferents but not the vestibular system (i.e., no stimulation of the otolith organs or semicircular canals). After a 3-min baseline period with the head in the normal erect position, subjects rotated their head to the side (approximately 90%) and maintained this position for 3 min. Head rotation was performed by the subjects in both the prone (n = 5) and sitting (n = 6) positions. Head rotation did not elicit changes in MSNA. Average MSNA, expressed as burst frequency and total activity, was 13 +/- 1 and 13 +/- 1 bursts/min and 146 +/-34 and 132 +/- 27 units/min during baseline and head rotation, respectively. There were no significant changes in calf blood flow (2.6 +/- 0.3 to 2.5 +/- 0.3 ml.100 ml-1.min-1, n = 8) and calf vascular resistance (39 +/- 4 to 41 +/- 4 units; n = 8). Heart rate (64 +/- 3 to 66 +/- 3 beats/min; P = 0.058) and mean arterial pressure (90 +/- 3 to 93 +/- 3; P HDNF was tested in 9 of the 13 subjects. MSNA was significantly increased by 79 +/- 12% (P HDNF. These findings indicate that neck afferents activated by horizontal neck rotation or flexion in the absence of significant force development do not elicit changes in MSNA. These findings support the concept that HDNF increases MSNA by the activation of the vestibular system. PMID:9475851

  12. Skin sympathetic nerve activity in humans during exposure to emotionally-charged images: sex differences

    Directory of Open Access Journals (Sweden)

    Rachael eBrown

    2014-03-01

    Full Text Available While it is known that anxiety or emotional arousal affects skin sympathetic nerve activity (SSNA, the galvanic skin response (GSR is the most widely used parameter to infer increases in SSNA during stress or emotional studies. We recently showed that SSNA provides a more sensitive measure of emotional state than effector-organ responses. The aim of the present study was to assess whether there are gender differences in the responses of SSNA and other physiological parameters such as blood pressure, heart rate, skin blood flow and sweat release, while subjects viewed neutral or emotionally-charged images from the International Affective Picture System. Changes in SSNA were assessed using microneurography in twenty subjects (ten male and ten female. Blocks of positively-charged (erotica or negatively-charge images (mutilation were presented in a quasi-random fashion, following a block of neutral images, with each block containing fifteen images and lasting two minutes. Images of both erotica and mutilation caused significant increases in SSNA, with increases being greater for males viewing erotica and greater for females viewing mutilation. The increases in SSNA were often coupled with sweat release and cutaneous vasoconstriction; however, these markers were not significantly different than those produced by viewing neutral images and were not always consistent with the SSNA increases. We conclude that SSNA increases with both positively-charged and negatively-charged emotional images, yet sex differences are present.

  13. Skin sympathetic nerve activity in humans during exposure to emotionally-charged images: sex differences.

    Science.gov (United States)

    Brown, Rachael; Macefield, Vaughan G

    2014-01-01

    While it is known that anxiety or emotional arousal affects skin sympathetic nerve activity (SSNA), the galvanic skin response (GSR) is the most widely used parameter to infer increases in SSNA during stress or emotional studies. We recently showed that SSNA provides a more sensitive measure of emotional state than effector-organ responses. The aim of the present study was to assess whether there are gender differences in the responses of SSNA and other physiological parameters such as blood pressure, heart rate, skin blood flow and sweat release, while subjects viewed neutral or emotionally-charged images from the International Affective Picture System (IAPS). Changes in SSNA were assessed using microneurography in 20 subjects (10 male and 10 female). Blocks of positively-charged (erotica) or negatively-charge images (mutilation) were presented in a quasi-random fashion, following a block of neutral images, with each block containing 15 images and lasting 2 min. Images of both erotica and mutilation caused significant increases in SSNA, with increases being greater for males viewing erotica and greater for females viewing mutilation. The increases in SSNA were often coupled with sweat release and cutaneous vasoconstriction; however, these markers were not significantly different than those produced by viewing neutral images and were not always consistent with the SSNA increases. We conclude that SSNA increases with both positively-charged and negatively-charged emotional images, yet sex differences are present. PMID:24678303

  14. Neuropeptide Y acts in the paraventricular nucleus to suppress sympathetic nerve activity and its baroreflex regulation.

    Science.gov (United States)

    Cassaglia, Priscila A; Shi, Zhigang; Li, Baoxin; Reis, Wagner L; Clute-Reinig, Nicholas M; Stern, Javier E; Brooks, Virginia L

    2014-04-01

    Neuropeptide Y (NPY), a brain neuromodulator that has been strongly implicated in the regulation of energy balance, also acts centrally to inhibit sympathetic nerve activity (SNA); however, the site and mechanism of action are unknown. In chloralose-anaesthetized female rats, nanoinjection of NPY into the paraventricular nucleus of the hypothalamus (PVN) dose-dependently suppressed lumbar SNA (LSNA) and its baroreflex regulation, and these effects were blocked by prior inhibition of NPY Y1 or Y5 receptors. Moreover, PVN injection of Y1 and Y5 receptor antagonists in otherwise untreated rats increased basal and baroreflex control of LSNA, indicating that endogenous NPY tonically inhibits PVN presympathetic neurons. The sympathoexcitation following blockade of PVN NPY inhibition was eliminated by prior PVN nanoinjection of the melanocortin 3/4 receptor inhibitor SHU9119. Moreover, presympathetic neurons, identified immunohistochemically using cholera toxin b neuronal tract tracing from the rostral ventrolateral medulla (RVLM), express NPY Y1 receptor immunoreactivity, and patch-clamp recordings revealed that both NPY and α-melanocyte-stimulating hormone (α-MSH) inhibit and stimulate, respectively, PVN-RVLM neurons. Collectively, these data suggest that PVN NPY inputs converge with α-MSH to influence presympathetic neurons. Together these results identify endogenous NPY as a novel and potent inhibitory neuromodulator within the PVN that may contribute to changes in SNA that occur in states associated with altered energy balance, such as obesity and pregnancy. PMID:24535439

  15. Psychobiology of PTSD in the Acute Aftermath of Trauma: Integrating Research on Coping, HPA Function and Sympathetic Nervous System Activity

    OpenAIRE

    Morris, Matthew C.; Rao, Uma

    2012-01-01

    Research on the psychobiological sequelae of trauma has typically focused on long-term alterations in individuals with chronic posttraumatic stress disorder (PTSD). Far less is known about the nature and course of psychobiological risk factors for PTSD during the acute aftermath of trauma. In this review, we summarize data from prospective studies focusing on the relationships among sympathetic nervous system activity, hypothalamic-pituitary-adrenal function, coping strategies and PTSD sympto...

  16. Acute inhibition of glial cells in the NTS does not affect respiratory and sympathetic activities in rats exposed to chronic intermittent hypoxia.

    Science.gov (United States)

    Costa, Kauê M; Moraes, Davi J A; Machado, Benedito H

    2013-02-16

    Recent studies suggest that neuron-glia interactions are involved in multiple aspects of neuronal activity regulation. In the nucleus tractus solitarius (NTS) neuron-glia interactions are thought to participate in the integration of autonomic responses to physiological challenges. However, it remains to be shown whether NTS glial cells might influence breathing and cardiovascular control, and also if they could be integral to the autonomic and respiratory responses to hypoxic challenges. Here, we investigated whether NTS glia play a tonic role in the modulation of central respiratory and sympathetic activities as well as in the changes in respiratory-sympathetic coupling induced by exposure to chronic intermittent hypoxia (CIH), a model of central autonomic and respiratory plasticity. We show that bilateral microinjections of fluorocitrate (FCt), a glial cell inhibitor, into the caudal and intermediate subnuclei of the NTS did not alter baseline respiratory and sympathetic parameters in in situ preparations of juvenile rats. Similar results were observed in rats previously exposed to CIH. Likewise, CIH-induced changes in respiratory-sympathetic coupling were unaffected by FCt-mediated inhibition. However, microinjection of FCt into the ventral medulla produced changes in respiratory frequency. Our results show that acute glial inhibition in the NTS does not affect baseline respiratory and sympathetic control. Additionally, we conclude that NTS glial cells may not be necessary for the continuous manifestation of sympathetic and respiratory adaptations to CIH. Our work provides evidence that neuron-glia interactions in the NTS do not participate in baseline respiratory and sympathetic control.

  17. Cerebrospinal Fluid Hypernatremia Elevates Sympathetic Nerve Activity and Blood Pressure via the Rostral Ventrolateral Medulla.

    Science.gov (United States)

    Stocker, Sean D; Lang, Susan M; Simmonds, Sarah S; Wenner, Megan M; Farquhar, William B

    2015-12-01

    Elevated NaCl concentrations of the cerebrospinal fluid increase sympathetic nerve activity (SNA) in salt-sensitive hypertension. Neurons of the rostral ventrolateral medulla (RVLM) play a pivotal role in the regulation of SNA and receive mono- or polysynaptic inputs from several hypothalamic structures responsive to hypernatremia. Therefore, the present study investigated the contribution of RVLM neurons to the SNA and pressor response to cerebrospinal fluid hypernatremia. Lateral ventricle infusion of 0.15 mol/L, 0.6 mol/L, and 1.0 mol/L NaCl (5 µL/10 minutes) produced concentration-dependent increases in lumbar SNA, adrenal SNA, and arterial blood pressure, despite no change in splanchnic SNA and a decrease in renal SNA. Ganglionic blockade with chlorisondamine or acute lesion of the lamina terminalis blocked or significantly attenuated these responses, respectively. RVLM microinjection of the gamma-aminobutyric acid (GABAA) agonist muscimol abolished the sympathoexcitatory response to intracerebroventricular infusion of 1 mol/L NaCl. Furthermore, blockade of ionotropic glutamate, but not angiotensin II type 1, receptors significantly attenuated the increase in lumbar SNA, adrenal SNA, and arterial blood pressure. Finally, single-unit recordings of spinally projecting RVLM neurons revealed 3 distinct populations based on discharge responses to intracerebroventricular infusion of 1 mol/L NaCl: type I excited (46%; 11/24), type II inhibited (37%; 9/24), and type III no change (17%; 4/24). All neurons with slow conduction velocities were type I cells. Collectively, these findings suggest that acute increases in cerebrospinal fluid NaCl concentrations selectively activate a discrete population of RVLM neurons through glutamate receptor activation to increase SNA and arterial blood pressure. PMID:26416846

  18. Nitric oxide impacts on angiotensin AT2 receptor modulation of high-pressure baroreflex control of renal sympathetic nerve activity in anaesthetized rats

    OpenAIRE

    Abdulla, M H; Johns, E. J.

    2013-01-01

    Aim Nitric oxide (NO) interacts with the local brain renin-angiotensin system to modulate sympathetic outflow and cardiovascular homoeostasis. This study investigated whether NO influenced the ability of angiotensin AT2 receptor activation to modify the high-pressure baroreceptor regulation of renal sympathetic nerve activity (RSNA) and heart rate (HR). Methods Anaesthetized (chloralose/urethane) rats were prepared to allow generation of baroreflex gain curves for RSNA or HR following intrace...

  19. Intragastric injection of Lactobacillus casei strain Shirota suppressed spleen sympathetic activation by central corticotrophin-releasing factor or peripheral 2-deoxy-d-glucose in anesthetized rats.

    Science.gov (United States)

    Tanida, Mamoru; Takada, Mai; Kato-Kataoka, Akito; Kawai, Mitsuhisa; Miyazaki, Kouji; Shibamoto, Toshishige

    2016-04-21

    Intragastric (IG) administration of probiotic strain Lactobacillus casei Shirota (LcS) decreases the sympathetic nerve outflow of anesthetized rats in a tissue-specific manner. In the present study, we examined the effects of IG administration of LcS on sympathetic activation induced by an intracerebroventricular (ICV) injection of corticotrophin-releasing factor (CRF) and an intravenous (IV) injection of 2-deoxy-d-glucose (2DG) or interleukin (IL)-1β in urethane-anesthetized rats. The IG administration of LcS differently affected the stimulatory responses of sympathetic nerve outflow to CRF. LcS suppressed the increase in splenic sympathetic nerve activity (Spleen-SNA), induced by central CRF, in a dose-dependent manner; however, it did not alter adrenal sympathetic nervous activity (ASNA). In contrast, LcS did not affect spleen-SNA and ASNA following an IV injection of IL-1β. On the other hand, IG administration of LcS suppressed the activation of ASNA following an IV injection of 2DG. These findings suggest that the suppression of central CRF-induced sympathetic activation by LcS is tissue-specific. Moreover, it can suppress the 2DG-induced sympathetic activation. Furthermore, we found that stomach-specific vagotomy attenuates the suppressive effect of LcS on CRF-mediated spleen-SNA activation. Thus, the present study suggests that LcS administered to the stomach may act on the afferent vagal nerve and send afferent signals to the brain to regulate efferent SNA induced by sympathetic stimulators. PMID:26971699

  20. Matured Hop Bittering Components Induce Thermogenesis in Brown Adipose Tissue via Sympathetic Nerve Activity.

    Directory of Open Access Journals (Sweden)

    Yumie Morimoto-Kobayashi

    Full Text Available Obesity is the principal symptom of metabolic syndrome, which refers to a group of risk factors that increase the likelihood of atherosclerosis. In recent decades there has been a sharp rise in the incidence of obesity throughout the developed world. Iso-α-acids, the bitter compounds derived from hops in beer, have been shown to prevent diet-induced obesity by increasing lipid oxidation in the liver and inhibition of lipid absorption from the intestine. Whereas the sharp bitterness induced by effective dose of iso-α-acids precludes their acceptance as a nutrient, matured hop bittering components (MHB appear to be more agreeable. Therefore, we tested MHB for an effect on ameliorating diet-induced body fat accumulation in rodents. MHB ingestion had a beneficial effect but, compared to iso-α-acids and despite containing structurally similar compounds, acted via different mechanisms to reduce body fat accumulation. MHB supplementation significantly reduced body weight gain, epididymal white adipose tissue weight, and plasma non-esterified free fatty acid levels in diet-induced obese mice. We also found that uncoupling protein 1 (UCP1 expression in brown adipose tissue (BAT was significantly increased in MHB-fed mice at both the mRNA and protein levels. In addition, MHB administration in rats induced the β-adrenergic signaling cascade, which is related to cAMP accumulation in BAT, suggesting that MHB could modulate sympathetic nerve activity innervating BAT (BAT-SNA. Indeed, single oral administration of MHB elevated BAT-SNA in rats, and this elevation was dissipated by subdiaphragmatic vagotomy. Single oral administration of MHB maintained BAT temperature at a significantly higher level than in control rats. Taken together, these findings indicate that MHB ameliorates diet-induced body fat accumulation, at least partly, by enhancing thermogenesis in BAT via BAT-SNA activation. Our data suggests that MHB is a useful tool for developing functional

  1. Region-specific changes in sympathetic nerve activity in angiotensin II-salt hypertension in the rat.

    Science.gov (United States)

    Osborn, John W; Fink, Gregory D

    2010-01-01

    It is now well accepted that many forms of experimental hypertension and human essential hypertension are caused by increased activity of the sympathetic nervous system. However, the role of region-specific changes in sympathetic nerve activity (SNA) in the pathogenesis of hypertension has been difficult to determine because methods for chronic measurement of SNA in conscious animals have not been available. We have recently combined indirect, and continuous and chronic direct, assessment of region-specific SNA to characterize hypertension produced by administration of angiotensin II (Ang II) to rats consuming a high-salt diet (Ang II-salt hypertension). Angiotensin II increases whole-body noradrenaline (NA) spillover and depressor responses to ganglionic blockade in rats consuming a high-salt diet, but not in rats on a normal-salt diet. Despite this evidence for increased 'whole-body SNA' in Ang II-salt hypertensive rats, renal SNA is decreased in this model and renal denervation does not attenuate the steady-state level of arterial pressure. In addition, neither lumbar SNA, which largely targets skeletal muscle, nor hindlimb NA spillover is changed from control levels in Ang II-salt hypertensive rats. However, surgical denervation of the splanchnic vascular bed attenuates/abolishes the increase in arterial pressure and total peripheral resistance, as well as the decrease in vascular capacitance, observed in Ang II-salt hypertensive rats. We hypothesize that the 'sympathetic signature' of Ang II-salt hypertension is characterized by increased splanchnic SNA, no change in skeletal muscle SNA and decreased renal SNA, and this sympathetic signature creates unique haemodynamic changes capable of producing sustained hypertension. PMID:19717492

  2. Turo (Qi Dance Training Attenuates Psychological Symptoms and Sympathetic Activation Induced by Mental Stress in Healthy Women

    Directory of Open Access Journals (Sweden)

    Hwa-Jin Lee

    2009-01-01

    Full Text Available Vagal withdrawal and sympathetic overactivity accompany various types of stress. Qi training is reported to reduce sympathetic hyper-reactivity in a stressful situation. Turo, which is a type of dance that uses the Meridian Qi System, may reduce the psychological symptoms induced by an imbalance of the autonomic nervous system (ANS. We observed whether Turo training alters psychopathological and psychological symptoms using the Symptom Checklist 90-Revision (SCL-90-R and examined whether it attenuates the stress response to mental stress in healthy adolescent females using the power spectrum analysis of heart rate variability (HRV. Twenty-one subjects received Turo training and 27 subjects were trained with mimicking movements. The SCL-90-R was measured before and after the 2-month training period. Heart rate (HR, total power (TP and the LF/HF ratio of HRV were compared between the Turo and control groups during and after mental stress. The somatization and hostility subscales of the SCL-90-R of the Turo group were significantly lower than those of the control group after 2 months. The increases in HR and the LF/HF ratio of HRV induced by the stress test were significantly lower in the Turo group than in the control group. The TP of the Turo group was significantly higher than that of the control group. The psychological symptoms and sympathetic activation induced by the artificial stress were significantly reduced by the Turo training. These findings suggest that Turo training can play a critical role in attenuating psychological symptoms and stress-induced sympathetic activation.

  3. Reduced nitric oxide in the rostral ventrolateral medulla enhances cardiac sympathetic afferent reflex in rats with chronic heart failure%延髓头端腹外侧区一氧化氮与慢性心力衰竭大鼠心交感传入反射的关系

    Institute of Scientific and Technical Information of China (English)

    朱国庆; 高兴亚; 张枫; 王玮

    2004-01-01

    The purpose of this study was to determine the effect of nitric oxide (NO) in the rostral ventrolateral medulla (RVLM)on the central integration of the cardiac sympathetic afferent reflex (CSAR) in normal rats and in rats with coronary ligationinduced chronic heart failure (CHF). Under α-chloralose and urethane anesthesia, mean arterial pressure, heart rate and renal sympathetic nerve activity (RSNA) were recorded at baseline and during elicitation of the CSAR evoked by electrical stimulation of the cardiac afferent sympathetic nerves in sino-aortic denervated and cervical vagotomized rats. A cannula was inserted into the left RVLM for microinjection of NO synthase inhibitor, S-methyl-L-thiocitruline (MeTC) or NO donor, S-nitroso-N-acetyl-penicillamine (SNAP). The CSAR was tested by electrical stimulation (5, 10, 20 and 30 Hz at 10 V for 1 ms) of the afferent cardiac sympathetic nerves. It was observed that (1) the responses of RSNA to stimulation were enhanced in rats with CHF; (2) MeTC (80nmol) potentiated the responses of RSNA to stimulation in sham rats but not in rats with CHF; (3) SNAP (50 nmol) depressed the enhanced RSNA response to stimulation in CHF rats but had no effect in sham rats; and (4) MeTC increased the baseline RSNA and MAP only in sham rats, but SNAP inhibited the baseline RSNA and MAP in both sham and CHF rats. These results indicate that reductance of NO in the RVLM is involved in the augmentation of CSAR in CHF rats.%为观察延髓头端腹外侧区(rostral ventrolateral medulla,RVLM)一氧化氮(NO)在慢性心力衰竭(chronic heartfailure,CHF)大鼠增强的心交感传入反射(cardiac sympathetic afferent reflex,CSAR)中的作用,实验在去压力感受器神经支配的结扎冠状动脉诱发的CHF大鼠和假手术SD大鼠进行,记录电刺激心交感传入神经中枢端前后的血压和肾交感神经活动(renal sympathetic nerve activity,RSNA)变化以评价CSAR.结果显示:(1)CHF大鼠的CSAR显著增强;(2)RVLM微量注

  4. Muscle pain perception and sympathetic nerve activity to exercise during opioid modulation

    Science.gov (United States)

    Cook, D. B.; O'Connor, P. J.; Ray, C. A.

    2000-01-01

    The purpose of this experiment was to examine the effects of the endogenous opioid system on forearm muscle pain and muscle sympathetic nerve activity (MSNA) during dynamic fatiguing exercise. Twelve college-age men (24 +/- 4 yr) performed graded (1-min stages; 30 contractions/min) handgrip to fatigue 1 h after the ingestion of either 60 mg codeine, 50 mg naltrexone, or placebo. Pain (0-10 scale) and exertion (0-10 and 6-20 scales) intensities were measured during the last 15 s of each minute of exercise and every 15 s during recovery. MSNA was measured continuously from the peroneal nerve in the left leg. Pain threshold occurred earlier [1.8 +/- 1, 2. 2 +/- 1, 2.2 +/- 1 J: codeine, naltrexone, and placebo, respectively] and was associated with a lower rating of perceived exertion (RPE) (2.7 +/- 2, 3.6 +/- 2, 3.8 +/- 2: codeine, naltrexone, and placebo, respectively) in the codeine condition compared with either the naltrexone or placebo conditions. There were no main effects (i.e., drugs) or interaction (i.e., drugs x time) for either forearm muscle pain or RPE during exercise [pain: F (2, 22) = 0.69, P = 0.51]. There was no effect of drug on MSNA, heart rate, or blood pressure during baseline, exercise, or recovery. Peak exercise MSNA responses were 21 +/- 1, 21 +/- 2.0, and 21 +/- 2.0 bursts/30 s for codeine, naltrexone, and placebo conditions, respectively. Peak mean arterial pressure responses were 135 +/- 4, 131 +/- 3, and 132 +/- 4 mmHg for codeine, naltrexone, and placebo conditions, respectively. It is concluded that neither 60 mg codeine nor 50 mg naltrexone has an effect on forearm muscle pain, exertion, or MSNA during high- intensity handgrip to fatigue.

  5. Effects of three days of dry immersion on muscle sympathetic nerve activity and arterial blood pressure in humans.

    Science.gov (United States)

    Iwase, S; Sugiyama, Y; Miwa, C; Kamiya, A; Mano, T; Ohira, Y; Shenkman, B; Egorov, A I; Kozlovskaya, I B

    2000-03-15

    The present study was performed to determine how sympathetic function is altered by simulated microgravity, dry immersion for 3 days, and to elucidate the mechanism of post-spaceflight orthostatic intolerance in humans. Six healthy men aged 21-36 years old participated in the study. Before and after the dry immersion, subjects performed head-up tilt (HUT) test to 30 degrees and 60 degrees (5 min each) with recordings of muscle sympathetic nerve activity (MSNA, by microneurography), electrocardiogram, and arterial blood pressure (Finapres). Resting MSNA was increased after dry immersion from 23.7+/-3.2 to 40.9+/-3.0 bursts/min (p<0.005) without significant changes in resting heart rate (HR). MSNA responsiveness to orthostasis showed no significant difference but HR response was significantly augmented after dry immersion (p<0. 005). A significant diastolic blood pressure fall at 5th min of 60 degrees HUT was observed in five orthostatic tolerant subjects despite enough MSNA discharge after dry immersion. A subject suffered from presyncope at 2 min after 60 degrees HUT. He showed gradual blood pressure fall 10 s after 60 degrees HUT with initially well-maintained MSNA response and then with a gradually attenuated MSNA, followed by a sudden MSNA withdrawal and abrupt blood pressure drop. In conclusion, dry immersion increased MSNA without changing MSNA response to orthostasis, and resting HR, while increasing the HR response to orthostasis. Analyses of MSNA and blood pressure changes in orthostatic tolerant subjects and a subject with presyncope suggested that not only insufficient vasoconstriction to sympathetic stimuli, but also a central mechanism to induce a sympathetic withdrawal might play a role in the development of orthostatic intolerance after microgravity exposure.

  6. Noninvasive ambulatory measurement system of cardiac activity.

    Science.gov (United States)

    Pino, Esteban J; Chavez, Javier A P; Aqueveque, Pablo

    2015-08-01

    This work implements a noninvasive system that measures the movements caused by cardiac activity. It uses unobtrusive Electro-Mechanical Films (EMFi) on the seat and on the backrest of a regular chair. The system detects ballistocardiogram (BCG) and respiration movements. Real data was obtained from 54 volunteers. 19 of them were measured in the laboratory and 35 in a hospital waiting room. Using a BIOPAC acquisition system, the ECG was measured simultaneously to the BCG for comparison. Wavelet Transform (WT) is a better option than Empirical Mode Decomposition (EMD) for signal extraction and produces higher effective measurement time. In the laboratory, the best results are obtained on the seat. The correlation index was 0.9800 and the Bland-Altman limits of agreement were 0.7136 ± 4.3673 [BPM]. In the hospital waiting room, the best results are also from the seat sensor. The correlation index was 0.9840, and the limits of agreement were 0.4386 ± 3.5884 [BPM]. The system is able to measure BCG in an unobtrusive way and determine the cardiac frequency with high precision. It is simple to use, which means the system can easily be used in non-standard settings: resting in a chair or couch, at the gym, schools or in a hospital waiting room, as shown. PMID:26738057

  7. Cardiac sympathetic dysfunction in Parkinson's disease. Relationship between results of 123I-MIBG scintigraphy and autonomic nervous function evaluated by the Valsalva maneuver

    International Nuclear Information System (INIS)

    We examined whether the results of 123I-MIBG scintigraphy reflect cardiac sympathetic nerve function in patients with Parkinson's disease (PD). The subjects were 62 patients with PD (age, 65.4±6.3 years) and 53 controls (65.2±7.1 years). All subjects underwent 123I-MIBG scintigraphy and QTc interval measurement on electrocardiogram (ECG). Hemodynamic autonomic function was estimated by the Valsalva maneuver in 37 subjects (63.9±5.2 years) randomly selected from the patients with PD. As control, the Valsalva maneuver was also done in 20 randomly selected controls (64.1±5.0 years), and 123I-MIBG scintigraphy was performed in 21 controls (67.7±5.3 years old). The subjects rested in a supine position for 20 min and were given an intravenous injection of 111 MBq 123I-MIBG. Relative organ uptake was determined by the region of interest (ROI) in the anterior view and the ratio of average pixel count in the heart (H) to that in the mediastinum (M) was calculated (H/M ratio) for early (after 15 min) and delayed (after 3 hrs) periods. The Valsalva maneuver was done by having the subjects exhale into a mouthpiece at an expiratory pressure of 40 mmHg for 15 seconds. Blood pressure and RR intervals were measured during the Valsalva maneuver by tonometry, using a noninvasive blood pressure monitoring system (ANS 508, Nihon Colin Co., Ltd.). Baroreceptor reflex sensitivities (BRS) of the second phase (BRS II) and fourth phase (BRS IV) of the Valsalva maneuver were calculated, and blood pressure elevations during the late second phase (IIp) and fourth phase (IVp) were measured. QTc was greater in the patients with PD (417 ms) than in the control subjects (409 ms). The H/M ratios of the early and delayed images in the patients with PD (1.76, 1.61) were significantly lower than those in the control subjects (2.56, 2.45). The early and delayed H/M ratios significantly correlated with the severity of disease according to Hoehn-Yahr stage. QTc interval and IVp significantly

  8. The human sympathetic nervous system: its relevance in hypertension and heart failure.

    Science.gov (United States)

    Parati, Gianfranco; Esler, Murray

    2012-05-01

    Evidence assembled in this review indicates that sympathetic nervous system dysfunction is crucial in the development of heart failure and essential hypertension. This takes the form of persistent and adverse activation of sympathetic outflows to the heart and kidneys in both conditions. An important goal for clinical scientists is translation of the knowledge of pathophysiology, such as this, into better treatment for patients. The achievement of this 'mechanisms to management' transition is at different stages of development with regard to the two disorders. Clinical translation is mature in cardiac failure, knowledge of cardiac neural pathophysiology having led to the introduction of beta-adrenergic blockers, an effective therapy. With essential hypertension perhaps we are on the cusp of effective translation, with recent successful testing of selective catheter-based renal sympathetic nerve ablation in patients with resistant hypertension, an intervention firmly based on the demonstration of activation of the renal sympathetic outflow. Additional evidence in this regard is provided by the results of pilot studies exploring the possibility to reduce blood pressure in resistant hypertensives through electrical stimulation of the area of carotid baroreceptors. Despite the general importance of the sympathetic nervous system in blood pressure regulation, and the specific demonstration that the blood pressure elevation in essential hypertension is commonly initiated and sustained by sympathetic nervous activation, drugs antagonizing this system are currently underutilized in the care of patients with hypertension. Use of beta-adrenergic blocking drugs is waning, given the propensity of this drug class to have adverse metabolic effects, including predisposition to diabetes development. The blood pressure lowering achieved with carotid baroreceptor stimulation and with the renal denervation device affirms the importance of the sympathetic nervous system in

  9. Sympathetic activity of S-(+-ketamine low doses in the epidural space

    Directory of Open Access Journals (Sweden)

    Slobodan Mihaljevic

    2014-07-01

    Full Text Available BACKGROUND AND OBJECTIVES: S-(+-ketamine is an intravenous anaesthetic and sympathomimetic with properties of local anaesthetic. It has an effect of an analgetic and local anaesthetic when administered epidurally, but there are no data whether low doses of S-(+-ketamine have sympathomimetic effects. The aim of this study was to determine whether low doses of S-(+-ketamine, given epidurally together with local anaesthetic, have any effect on sympathetic nervous system, both systemic and below the level of anaesthetic block. METHODS: The study was conducted on two groups of patients to whom epidural anaesthesia was administered to. Local anaesthesia (0.5% bupivacaine was given to one group (control group while local anaesthesia and S-(+-ketamine were given to other group. Age, height, weight, systolic, diastolic and mean arterial blood pressure were measured. Non-competitive enzyme immunochemistry method (Cat Combi ELISA was used to determine the concentrations of catecholamines (adrenaline and noradrenaline. Immunoenzymometric determination with luminescent substrate on a machine called Vitros Eci was used to determine the concentration of cortisol. Pulse transit time was measured using photoplethysmography. Mann-Whitney U-test, Wilcoxon test and Friedman ANOVA were the statistical tests. Blood pressure, pulse, adrenaline, noradrenaline and cortisol concentrations were measured in order to estimate systemic sympathetic effects. RESULTS: 40 patients in the control group were given 0.5% bupivacaine and 40 patients in the test group were given 0.5% bupivacaine with S-(+-ketamine. Value p < 0.05 has been taken as a limit of statistical significance. CONCLUSIONS: Low dose of S-(+-ketamine administered epidurally had no sympathomimetic effects; it did not change blood pressure, pulse, serum hormones or pulse transit time. Low dose of S-(+-ketamine administered epidurally did not deepen sympathetic block. Adding 25 mg of S-(+-ketamine to 0

  10. Cardiac allograft immune activation: current perspectives

    Directory of Open Access Journals (Sweden)

    Chang D

    2014-12-01

    Full Text Available David Chang, Jon Kobashigawa Cedars-Sinai Heart Institute, Los Angeles, CA, USA Abstract: Heart transplant remains the most durable option for end-stage heart disease. Cardiac allograft immune activation and heart transplant rejection remain among the main complications limiting graft and recipient survival. Mediators of the immune system can cause different forms of rejection post-heart transplant. Types of heart transplant rejection include hyperacute rejection, cellular rejection, antibody-mediated rejection, and chronic rejection. In this review, we will summarize the innate and adaptive immune responses which influence the post-heart transplant recipient. Different forms of rejection and their clinical presentation, detection, and immune monitoring will be discussed. Treatment of heart transplant rejection will be examined. We will discuss potential treatment strategies for preventing rejection post-transplant in immunologically high-risk patients with antibody sensitization. Keywords: heart transplant, innate immunity, adaptive immunity, rejection, immunosuppression

  11. Different patterns of cardiac sympathetic denervation in tremor-type compared to akinetic-rigid-type Parkinson's disease: molecular imaging with ¹²³I-MIBG.

    Science.gov (United States)

    Chiaravalloti, A; Stefani, A; Tavolozza, M; Pierantozzi, M; Di Biagio, D; Olivola, E; Di Pietro, B; Stampanoni, M; Danieli, R; Simonetti, G; Stanzione, P; Schillaci, O

    2012-12-01

    The aim of this study was to evaluate the correlation between the clinical motor phenotypes of Parkinson's disease (PD) and ¹²³I-MIBG myocardial uptake. In total, 53 patients with PD [31 males and 22 females, mean age 62±10 years; 19 Hoehn & Yahr (H&Y) stage 1, 9 stage 1.5, 15 stage 2 and 10 at stage 3] were examined and subdivided into different clinical forms on the basis of dominance of resting tremor (n=19, TDT) and bradykinesia plus rigidity (n=34, ART). This status was correlated with the semi-quantitative analysis of ¹²³I-MIBG myocardial uptake. An age-matched control group of 18 patients was recruited (8 males and 10 females, mean age 62.4±16.3 years). ¹²³I-MIBG myocardial uptake significantly correlated with disease duration in early (r²=0.1894; P=0.0028) and delayed images (r²=0.1795; P=0.0037) in PD patients, while no correlation was found when considering age at examination, UPDRS III motor examination section score and H&Y score. PD patients showed a reduced ¹²³I-MIBG myocardial uptake compared to the control group in early (P=0.0026) and delayed images (P=0.0040), and ¹²³I-MIBG myocardial uptake was significantly lower in delayed images in TDT patients compared with ART patients (P=0.0167). A decrease was detected in the heart-to-mediastinum (H/M) ratio in delayed images compared to that of the early images in TDT patients (P=0.0040) and in the whole PD population (P=0.0012), while no differences were found in ART patients (P=0.1043). The results of the present study revealed that the cardiac sympathetic system is more severely impaired in TDT than in ART patients and ¹²³I-MIBG molecular imaging has the potential help in improving therapeutic planning in these patients. PMID:23023866

  12. Regulation of sympathetic nervous system function after cardiovascular deconditioning

    Science.gov (United States)

    Hasser, E. M.; Moffitt, J. A.

    2001-01-01

    Humans subjected to prolonged periods of bed rest or microgravity undergo deconditioning of the cardiovascular system, characterized by resting tachycardia, reduced exercise capability, and a predisposition for orthostatic intolerance. These changes in cardiovascular function are likely due to a combination of factors, including changes in control of body fluid balance or cardiac alterations resulting in inadequate maintenance of stroke volume, altered arterial or venous vascular function, reduced activation of cardiovascular hormones, and diminished autonomic reflex function. There is evidence indicating a role for each of these mechanisms. Diminished reflex activation of the sympathetic nervous system and subsequent vasoconstriction appear to play an important role. Studies utilizing the hindlimb-unloaded (HU) rat, an animal model of deconditioning, evaluated the potential role of altered arterial baroreflex control of the sympathetic nervous system. These studies indicate that HU results in blunted baroreflex-mediated activation of both renal and lumbar sympathetic nerve activity in response to a hypotensive stimulus. HU rats are less able to maintain arterial pressure during hemorrhage, suggesting that diminished ability to increase sympathetic activity has functional consequences for the animal. Reflex control of vasopressin secretion appears to be enhanced following HU. Blunted baroreflex-mediated sympathoexcitation appears to involve altered central nervous system function. Baroreceptor afferent activity in response to changes in arterial pressure is unaltered in HU rats. However, increases in efferent sympathetic nerve activity for a given decrease in afferent input are blunted after HU. This altered central nervous system processing of baroreceptor inputs appears to involve an effect at the rostral ventrolateral medulla (RVLM). Specifically, it appears that tonic GABAA-mediated inhibition of the RVLM is enhanced after HU. Augmented inhibition apparently

  13. Sympathetic activity of S-(+)-ketamine low doses in the epidural space

    OpenAIRE

    2014-01-01

    BACKGROUND AND OBJECTIVES: S-(+)-ketamine is an intravenous anaesthetic and sympathomimetic with properties of local anaesthetic. It has an effect of an analgetic and local anaesthetic when administered epidurally, but there are no data whether low doses of S-(+)-ketamine have sympathomimetic effects. The aim of this study was to determine whether low doses of S-(+)-ketamine, given epidurally together with local anaesthetic, have any effect on sympathetic nervous system, both systemic and be...

  14. Noradrenaline release from rat sympathetic neurones triggered by activation of B2 bradykinin receptors

    OpenAIRE

    Boehm, Stefan; Huck, Sigismund

    1997-01-01

    The role of bradykinin receptors in the regulation of sympathetic transmitter release was investigated in primary cultures of neurones dissociated from superior cervical ganglia of neonatal rats. These cultures were loaded with [3H]-noradrenaline and the outflow of radioactivity was determined under continuous superfusion.Bradykinin (100 nmol l−1 applied for 10 min) caused a transient increase in tritium outflow that reached a peak within four minutes after the beginning of the application an...

  15. Activation of the sympathetic nervous system mediates hypophagic and anxiety-like effects of CB₁ receptor blockade.

    Science.gov (United States)

    Bellocchio, Luigi; Soria-Gómez, Edgar; Quarta, Carmelo; Metna-Laurent, Mathilde; Cardinal, Pierre; Binder, Elke; Cannich, Astrid; Delamarre, Anna; Häring, Martin; Martín-Fontecha, Mar; Vega, David; Leste-Lasserre, Thierry; Bartsch, Dusan; Monory, Krisztina; Lutz, Beat; Chaouloff, Francis; Pagotto, Uberto; Guzman, Manuel; Cota, Daniela; Marsicano, Giovanni

    2013-03-19

    Complex interactions between periphery and the brain regulate food intake in mammals. Cannabinoid type-1 (CB1) receptor antagonists are potent hypophagic agents, but the sites where this acute action is exerted and the underlying mechanisms are not fully elucidated. To dissect the mechanisms underlying the hypophagic effect of CB1 receptor blockade, we combined the acute injection of the CB1 receptor antagonist rimonabant with the use of conditional CB1-knockout mice, as well as with pharmacological modulation of different central and peripheral circuits. Fasting/refeeding experiments revealed that CB1 receptor signaling in many specific brain neurons is dispensable for the acute hypophagic effects of rimonabant. CB1 receptor antagonist-induced hypophagia was fully abolished by peripheral blockade of β-adrenergic transmission, suggesting that this effect is mediated by increased activity of the sympathetic nervous system. Consistently, we found that rimonabant increases gastrointestinal metabolism via increased peripheral β-adrenergic receptor signaling in peripheral organs, including the gastrointestinal tract. Blockade of both visceral afferents and glutamatergic transmission in the nucleus tractus solitarii abolished rimonabant-induced hypophagia. Importantly, these mechanisms were specifically triggered by lipid-deprivation, revealing a nutrient-specific component acutely regulated by CB1 receptor blockade. Finally, peripheral blockade of sympathetic neurotransmission also blunted central effects of CB1 receptor blockade, such as fear responses and anxiety-like behaviors. These data demonstrate that, independently of their site of origin, important effects of CB1 receptor blockade are expressed via activation of peripheral sympathetic activity. Thus, CB1 receptors modulate bidirectional circuits between the periphery and the brain to regulate feeding and other behaviors.

  16. Bursting into space: alterations of sympathetic control by space travel

    Science.gov (United States)

    Eckberg, D. L.

    2003-01-01

    AIM: Astronauts return to Earth with reduced red cell masses and hypovolaemia. Not surprisingly, when they stand, their heart rates may speed inordinately, their blood pressures may fall, and some may experience frank syncope. We studied autonomic function in six male astronauts (average +/- SEM age: 40 +/- 2 years) before, during, and after the 16-day Neurolab space shuttle mission. METHOD: We recorded electrocardiograms, finger photoplethysmographic arterial pressures, respiration, peroneal nerve muscle sympathetic activity, plasma noradrenaline and noradrenaline kinetics, and cardiac output, and we calculated stroke volume and total peripheral resistance. We perturbed autonomic function before and during spaceflight with graded Valsalva manoeuvres and lower body suction, and before and after the mission with passive upright tilt. RESULTS: In-flight baseline sympathetic nerve activity was increased above pre-flight levels (by 10-33%) in three subjects, in whom noradrenaline spillover and clearance also were increased. Valsalva straining provoked greater reductions of arterial pressure, and proportionally greater sympathetic responses in space than on Earth. Lower body suction elicited greater increases of sympathetic nerve activity, plasma noradrenaline, and noradrenaline spillover in space than on Earth. After the Neurolab mission, left ventricular stroke volume was lower and heart rate was higher during tilt, than before spaceflight. No astronaut experienced orthostatic hypotension or pre-syncope during 10 min of post-flight tilting. CONCLUSION: We conclude that baseline sympathetic outflow, however measured, is higher in space than on earth, and that augmented sympathetic nerve responses to Valsalva straining, lower body suction, and post-flight upright tilt represent normal adjustments to greater haemodynamic stresses associated with hypovolaemia.

  17. Motion sickness is associated with an increase in vestibular modulation of skin but not muscle sympathetic nerve activity.

    Science.gov (United States)

    Klingberg, Danielle; Hammam, Elie; Macefield, Vaughan G

    2015-08-01

    We have previously shown that sinusoidal galvanic vestibular stimulation (sGVS), delivered bilaterally at frequencies of 0.08-2.00 Hz, causes a pronounced modulation of muscle sympathetic nerve activity (MSNA) and skin sympathetic nerve activity (SSNA), together with robust frequency-dependent illusions of side-to-side motion. At low frequencies of sGVS (≤0.2 Hz), some subjects report nausea, so we tested the hypothesis that vestibular modulation of MSNA and SSNA is augmented in individuals reporting nausea. MSNA was recorded via tungsten microelectrodes inserted into the left common peroneal nerve in 22 awake, seated subjects; SSNA was recorded in 14 subjects. Bipolar binaural sGVS (±2 mA, 100 cycles) was applied to the mastoid processes at 0.08, 0.13, and 0.18 Hz. Nausea was reported by 21 out of 36 subjects (58 %), but across frequencies of sGVS there was no difference in the magnitude of the vestibular modulation of MSNA in subjects who reported nausea (27.1 ± 1.8 %) and those who did not (30.4 ± 2.9 %). This contrasts with the significantly greater vestibular modulation of SSNA with nausea (41.1 ± 2.0 vs. 28.7 ± 3.1 %) and indicates an organ-specific modulation of sympathetic outflow via the vestibular system during motion sickness. PMID:26025612

  18. Angiotensin II--nitric oxide interactions in the control of sympathetic outflow in heart failure.

    Science.gov (United States)

    Zucker, I H; Liu, J L

    2000-03-01

    Activation of the sympathetic nervous system is a compensatory mechanism which initially provides support for the circulation in the face of a falling cardiac output. It has been recognized for some time that chronic elevation of sympathetic outflow with the consequent increase in plasma norepinephrine, is counterproductive to improving cardiac function. Indeed, therapeutic targeting to block excessive sympathetic activation in heart failure is becoming a more accepted modality. The mechanism(s) by which sympathetic excitation occurs in the heart failure state are not completely understood. Components of abnormal cardiovascular reflex regulation most likely contribute to this sympatho-excitation. However, central mechanisms which relate to the elaboration of angiotensin II (Ang II) and nitric oxide (NO) may also play an important role. Ang II has been shown to be a sympatho-excitatory peptide in the central nervous system while NO is sympatho-inhibitory. Recent studies have demonstrated that blockade of Ang II receptors of the AT(1) subtype augments arterial baroreflex control of sympathetic nerve activity in the heart failure state, thereby predisposing to a reduction in sympathetic tone. Ang II and NO interact to regulate sympathetic outflow. Blockade of NO production in normal conscious rabbits was only capable of increasing sympathetic outflow when accompanied by a background infusion of Ang II. Conversely, providing a source of NO to rabbits with heart failure reduced sympathetic nerve activity when accompanied by blockade of AT(1) receptors. Chronic heart failure is also associated with a decrease in NO synthesis in the brain as indicated by a reduction in the mRNA for the neuronal isoform (nNOS). Chronic blockade of Ang II receptors can up regulate nNOS expression. In addition, exercise training of rabbits with developing heart failure has been shown to reduce sympathetic tone, decrease plasma Ang II, improve arterial baroreflex function and increase n

  19. Alterations in electrodermal activity and cardiac parasympathetic tone during hypnosis.

    Science.gov (United States)

    Kekecs, Zoltán; Szekely, Anna; Varga, Katalin

    2016-02-01

    Exploring autonomic nervous system (ANS) changes during hypnosis is critical for understanding the nature and extent of the hypnotic phenomenon and for identifying the mechanisms underlying the effects of hypnosis in different medical conditions. To assess ANS changes during hypnosis, electrodermal activity and pulse rate variability (PRV) were measured in 121 young adults. Participants either received hypnotic induction (hypnosis condition) or listened to music (control condition), and both groups were exposed to test suggestions. Blocks of silence and experimental sound stimuli were presented at baseline, after induction, and after de-induction. Skin conductance level (SCL) and high frequency (HF) power of PRV measured at each phase were compared between groups. Hypnosis decreased SCL compared to the control condition; however, there were no group differences in HF power. Furthermore, hypnotic suggestibility did not moderate ANS changes in the hypnosis group. These findings indicate that hypnosis reduces tonic sympathetic nervous system activity, which might explain why hypnosis is effective in the treatment of disorders with strong sympathetic nervous system involvement, such as rheumatoid arthritis, hot flashes, hypertension, and chronic pain. Further studies with different control conditions are required to examine the specificity of the sympathetic effects of hypnosis.

  20. Alterations in electrodermal activity and cardiac parasympathetic tone during hypnosis.

    Science.gov (United States)

    Kekecs, Zoltán; Szekely, Anna; Varga, Katalin

    2016-02-01

    Exploring autonomic nervous system (ANS) changes during hypnosis is critical for understanding the nature and extent of the hypnotic phenomenon and for identifying the mechanisms underlying the effects of hypnosis in different medical conditions. To assess ANS changes during hypnosis, electrodermal activity and pulse rate variability (PRV) were measured in 121 young adults. Participants either received hypnotic induction (hypnosis condition) or listened to music (control condition), and both groups were exposed to test suggestions. Blocks of silence and experimental sound stimuli were presented at baseline, after induction, and after de-induction. Skin conductance level (SCL) and high frequency (HF) power of PRV measured at each phase were compared between groups. Hypnosis decreased SCL compared to the control condition; however, there were no group differences in HF power. Furthermore, hypnotic suggestibility did not moderate ANS changes in the hypnosis group. These findings indicate that hypnosis reduces tonic sympathetic nervous system activity, which might explain why hypnosis is effective in the treatment of disorders with strong sympathetic nervous system involvement, such as rheumatoid arthritis, hot flashes, hypertension, and chronic pain. Further studies with different control conditions are required to examine the specificity of the sympathetic effects of hypnosis. PMID:26488759

  1. Influence of laser radiation on some integrative indications of sympathetic-adrenal system activity

    Science.gov (United States)

    Pronchenkova, G. F.; Chesnokova, N. P.

    2002-07-01

    One of the goals of this experimental research is elucidation of the influence of laser radiation on the functional state of the sympathetic-adrenal system of a microorganism, which to a large extent defines the intensity of an inflammatory reaction development, and in particular regeneration and repair process in the zone of post traumatic influence of infectious and non-infectious pathogen factors. We have also studied the alteration of adrenaline and noradrenaline content in the wound itself in the dynamics of regeneration.

  2. Burnout versus work engagement in their effects on 24-hour ambulatory monitored cardiac autonomic function

    NARCIS (Netherlands)

    L.J.P. van Doornen (Lorenz); J.H. Houtveen (Jan); S. Langelaan (Saar); A.B. Bakker (Arnold); W. van Rhenen (Willem); W.B. Schaufeli (Wilmar)

    2009-01-01

    textabstractBurnout has been associated with increased risk of cardiovascular disease. This relationship may be mediated by a stress-related disruption in cardiac autonomic activity. The aim of the present study was to assess cardiac autonomic activity (sympathetic and parasympathetic) during a work

  3. Perfectionism and Effort-Related Cardiac Activity: Do Perfectionists Try Harder?

    Science.gov (United States)

    Harper, Kelly L; Eddington, Kari M; Silvia, Paul J

    2016-01-01

    Do perfectionists try harder? Previous research on perfectionism and effort has used self-report items and task performance as indicators of effort. The current study investigated whether individual differences in perfectionism predicted effort-related cardiac activity during a mental effort task. Based on past research that suggests adaptive perfectionism is associated with higher effort, it was hypothesized that self-oriented perfectionism (SOP) would predict increased effort on the task. One hundred and eleven college students completed the Multidimensional Perfectionism Scale (MPS) and a self-paced parity task in which they received a small cash reward (3 cents) for each correct response. Impedance cardiography was used to assess autonomic reactivity, and regression models tested whether SOP and socially prescribed perfectionism (SPP) explained autonomic reactivity. Overall, participants showed both sympathetic (faster pre-ejection period; PEP) and parasympathetic activation (elevated high-frequency heart rate variability; HRV) during the task, reflecting higher effort and engagement. Contrary to predictions, individual differences in perfectionism did not moderate cardiac reactivity. These findings draw attention to the importance of assessing physiological components of effort and motivation directly rather than inferring them from task performance or self-reported effort. PMID:27483467

  4. Synergistic activation of cardiac genes by myocardin and Tbx5.

    Directory of Open Access Journals (Sweden)

    Chunbo Wang

    Full Text Available Myocardial differentiation is associated with the activation and expression of an array of cardiac specific genes. However, the transcriptional networks that control cardiac gene expression are not completely understood. Myocardin is a cardiac and smooth muscle-specific expressed transcriptional coactivator of Serum Response Factor (SRF and is able to potently activate cardiac and smooth muscle gene expression during development. We hypothesize that myocardin discriminates between cardiac and smooth muscle specific genes by associating with distinct co-factors. Here, we show that myocardin directly interacts with Tbx5, a member of the T-box family of transcription factors involved in the Holt-Oram syndrome. Tbx5 synergizes with myocardin to activate expression of the cardiac specific genes atrial natriuretic factor (ANF and alpha myosin heavy chain (α-MHC, but not that of smooth muscle specific genes SM22 or smooth muscle myosin heavy chain (SM-MHC. We found that this synergistic activation of shared target genes is dependent on the binding sites for Tbx5, T-box factor-Binding Elements (TBEs. Myocardin and Tbx5 physically interact and their interaction domains were mapped to the basic domain and the coil domain of myocardin and Tbx5, respectively. Our analysis demonstrates that the Tbx5G80R mutation, which leads to the Holt-Oram syndrome in humans, failed to synergize with myocardin to activate cardiac gene expression. These data uncover a key role for Tbx5 and myocardin in establishing the transcriptional foundation for cardiac gene activation and suggest that the interaction of myocardin and Tbx5 maybe involved in cardiac development and diseases.

  5. Vitamin D Levels Are Associated with Cardiac Autonomic Activity in Healthy Humans

    Directory of Open Access Journals (Sweden)

    Linda Ellis

    2013-06-01

    Full Text Available Vitamin D deficiency (≤50nmol/L 25-hydroxy vitamin D is a cardiovascular (CV risk factor that affects approximately one billion people worldwide, particularly those affected by chronic kidney disease (CKD. Individuals with CKD demonstrate abnormal cardiac autonomic nervous system activity, which has been linked to the significant rates of CV-related mortality in this population. Whether vitamin D deficiency has a direct association with regulation of cardiac autonomic activity has never been explored in humans. Methods: Thirty-four (34 healthy, normotensive subjects were studied and categorized based on 25-hydroxy vitamin D deficiency (deficient vs. non-deficient, n = 7 vs. 27, as well as 1,25-dihydroxy vitamin D levels (above vs. below 25th percentile, n = 8 vs. 26. Power spectral analysis of electrocardiogram recordings provided measures of cardiac autonomic activity across low frequency (LF and high frequency (HF, representative of vagal contribution bands, representative of the sympathetic and vagal limbs of the autonomic nervous system when transformed to normalized units (nu, respectively, as well as overall cardiosympathovagal balance (LF:HF during graded angiotensin II (AngII challenge (3 ng/kg/min × 30 min, 6 ng/kg/min × 30 min. Results: At baseline, significant suppression of sympathovagal balance was observed in the 25-hydroxy vitamin D-deficient participants (LF:HF, p = 0.02 vs. non-deficient, although no other differences were observed throughout AngII challenge. Participants in the lowest 1,25-dihydroxy VD quartile experienced significant withdrawal of inhibitory vagal control, as well as altered overall sympathovagal balance throughout AngII challenge (HF, mean difference = −6.98 ± 3 nu, p = 0.05; LF:HF, mean difference = 0.34 ± 0.1, p = 0.043 vs. above 25th percentile. Conclusions: Vitamin D deficiency is associated with suppression of resting cardiac autonomic activity, while low 1,25-dihydroxy vitamin D levels are

  6. P2Y1 receptors expressed by C1 neurons determine peripheral chemoreceptor modulation of breathing, sympathetic activity, and blood pressure.

    Science.gov (United States)

    Wenker, Ian C; Sobrinho, Cleyton R; Takakura, Ana C; Mulkey, Daniel K; Moreira, Thiago S

    2013-08-01

    Catecholaminergic C1 cells of the rostral ventrolateral medulla (RVLM) are key determinants of the sympathoexcitatory response to peripheral chemoreceptor activation. Overactivation of this reflex is thought to contribute to increased sympathetic activity and hypertension; however, molecular mechanisms linking peripheral chemoreceptor drive to hypertension remain poorly understood. We have recently determined that activation of P2Y1 receptors in the RVLM mimicked effects of peripheral chemoreceptor activation. Therefore, we hypothesize that P2Y1 receptors regulate peripheral chemoreceptor drive in this region. Here, we determine whether P2Y1 receptors are expressed by C1 neurons in the RVLM and contribute to peripheral chemoreceptor control of breathing, sympathetic activity, and blood pressure. We found that injection of a specific P2Y1 receptor agonist (MRS2365) into the RVLM of anesthetized adult rats increased phrenic nerve activity (≈55%), sympathetic nerve activity (38 ± 6%), and blood pressure (23 ± 1 mm Hg), whereas application of a specific P2Y1 receptor antagonist (MRS2179) decreased peripheral chemoreceptor-mediated activation of phrenic nerve activity, sympathetic nerve activity, and blood pressure. To establish that P2Y1 receptors are expressed by C1 cells, we determine in the brain slice preparation using cell-attached recording techniques that cells responsive to MRS2365 are immunoreactive for tyrosine hydroxylase (a marker of C1 cells), and we determine in vivo that C1-lesioned animals do not respond to RVLM injection of MRS2365. These data identify P2Y1 receptors as key determinants of peripheral chemoreceptor regulation of breathing, sympathetic nerve activity, and blood pressure.

  7. Refractory Hypertension: Evidence of Heightened Sympathetic Activity as a Cause of Antihypertensive Treatment Failure.

    Science.gov (United States)

    Dudenbostel, Tanja; Acelajado, Maria C; Pisoni, Roberto; Li, Peng; Oparil, Suzanne; Calhoun, David A

    2015-07-01

    Refractory hypertension is an extreme phenotype of treatment failure defined as uncontrolled blood pressure in spite of ≥5 classes of antihypertensive agents, including chlorthalidone and a mineralocorticoid receptor antagonist. A prospective evaluation of possible mechanisms of refractory hypertension has not been done. The goal of this study was to test for evidence of heightened sympathetic tone as indicated by 24-hour urinary normetanephrine levels, clinic and ambulatory heart rate (HR), HR variability, arterial stiffness as indexed by pulse wave velocity, and systemic vascular resistance compared with patients with controlled resistant hypertension. Forty-four consecutive patients, 15 with refractory and 29 with controlled resistant hypertension, were evaluated prospectively. Refractory hypertensive patients were younger (48±13.3 versus 56.5±14.1 years; P=0.038) and more likely women (80.0 versus 51.9%; P=0.047) compared with patients with controlled resistant hypertension. They also had higher urinary normetanephrine levels (464.4±250.2 versus 309.8±147.6 µg per 24 hours; P=0.03), higher clinic HR (77.8±7.7 versus 68.8±7.6 bpm; P=0.001) and 24-hour ambulatory HR (77.8±7.7 versus 68.8±7.6; P=0.0018), higher pulse wave velocity (11.8±2.2 versus 9.4±1.5 m/s; P=0.009), reduced HR variability (4.48 versus 6.11; P=0.03), and higher systemic vascular resistance (3795±1753 versus 2382±349 dyne·s·cm(5)·m(2); P=0.008). These findings are consistent with heightened sympathetic tone being a major contributor to antihypertensive treatment failure and highlight the need for effective sympatholytic therapies in patients with refractory hypertension.

  8. Concurrent sympathetic activation and vagal withdrawal in hyperthyroidism: Evidence from detrended fluctuation analysis of heart rate variability

    Science.gov (United States)

    Chen, Jin-Long; Shiau, Yuo-Hsien; Tseng, Yin-Jiun; Chiu, Hung-Wen; Hsiao, Tzu-Chien; Wessel, Niels; Kurths, Jürgen; Chu, Woei-Chyn

    2010-05-01

    Despite many previous studies on the association between hyperthyroidism and the hyperadrenergic state, controversies still exist. Detrended fluctuation analysis (DFA) is a well recognized method in the nonlinear analysis of heart rate variability (HRV), and it has physiological significance related to the autonomic nervous system. In particular, an increased short-term scaling exponent α1 calculated from DFA is associated with both increased sympathetic activity and decreased vagal activity. No study has investigated the DFA of HRV in hyperthyroidism. This study was designed to assess the sympathovagal balance in hyperthyroidism. We performed the DFA along with the linear analysis of HRV in 36 hyperthyroid Graves’ disease patients (32 females and 4 males; age 30 ± 1 years, means ± SE) and 36 normal controls matched by sex, age and body mass index. Compared with the normal controls, the hyperthyroid patients revealed a significant increase ( P<0.001) in α1 (hyperthyroid 1.28±0.04 versus control 0.91±0.02), long-term scaling exponent α2 (1.05±0.02 versus 0.90±0.01), overall scaling exponent α (1.11±0.02 versus 0.89±0.01), low frequency power in normalized units (LF%) and the ratio of low frequency power to high frequency power (LF/HF); and a significant decrease ( P<0.001) in the standard deviation of the R-R intervals (SDNN) and high frequency power (HF). In conclusion, hyperthyroidism is characterized by concurrent sympathetic activation and vagal withdrawal. This sympathovagal imbalance state in hyperthyroidism helps to explain the higher prevalence of atrial fibrillation and exercise intolerance among hyperthyroid patients.

  9. Psychobiology of PTSD in the acute aftermath of trauma: Integrating research on coping, HPA function and sympathetic nervous system activity.

    Science.gov (United States)

    Morris, Matthew C; Rao, Uma

    2013-02-01

    Research on the psychobiological sequelae of trauma has typically focused on long-term alterations in individuals with chronic posttraumatic stress disorder (PTSD). Far less is known about the nature and course of psychobiological risk factors for PTSD during the acute aftermath of trauma. In this review, we summarize data from prospective studies focusing on the relationships among sympathetic nervous system activity, hypothalamic-pituitary-adrenal function, coping strategies and PTSD symptoms during the early recovery (or non-recovery) phase. Findings from pertinent studies are integrated to inform psychobiological profiles of PTSD-risk in children and adults in the context of existing models of PTSD-onset and maintenance. Data regarding bidirectional relations between coping strategies and stress hormones is reviewed. Limitations of existing literature and recommendations for future research are discussed.

  10. Changes in baroreflex control of renal sympathetic nerve activity in high-fat-fed rats as a predictor of hypertension.

    Science.gov (United States)

    Fardin, Núbia M; Oyama, Lila M; Campos, Ruy R

    2012-08-01

    There is evidence that obesity is associated with increased sympathetic activity and hypertension. However, the mechanisms responsible for these changes are not fully understood. Therefore, the aim of the present study was to evaluate the cardiovascular function and the baroreceptor reflex control of renal sympathetic nerve activity (rSNA) in rats exposed to a high-fat diet over different periods (10 and 20 weeks) compared to control rats. Serum leptin levels were assessed for all time points. Male Wistar rats weighing 150-180 g were used. Four groups of rats were studied: control 10 weeks (Ct10), obese 10 weeks (Ob10), control 20 weeks (Ct20), and obese 20 weeks (Ob20). Blood pressure (BP) and rSNA were recorded in urethane-anesthetized rats (1.4 g/kg, intravenous).The sensitivity of rSNA responses to baroreceptor reflex was assessed by changes in BP induced by increasing doses of phenylephrine or sodium nitroprusside. Significant and progressive increases in serum leptin levels were found in the obese rats, but not in the control rats. No changes in basal BP or rSNA were found in the Ob10 and Ob20 groups; however, a significant impairment in the baroreceptor sensitivity was observed in the Ob20 group for phenylephrine (slope Ob20: -0.78 ± 0.12 vs. Ct20: -1.00 ± 0.08 potential per second (pps)/mm Hg, P sodium nitroprusside (slope Ob20: -0.82 ± 0.09 vs. 1.13 ± 0.13 pps/mm Hg, P < 0.05). The results suggest that the baroreceptor dysfunction that controls the rSNA is an initial change in the obesity induced in high-fat-fed rats, which might be a predictor of sympathoexcitation and hypertension associated to obesity. PMID:22257982

  11. Endothelial and Neuronal Nitric Oxide Activate Distinct Pathways on Sympathetic Neurotransmission in Rat Tail and Mesenteric Arteries.

    Directory of Open Access Journals (Sweden)

    Joana Beatriz Sousa

    Full Text Available Nitric oxide (NO seems to contribute to vascular homeostasis regulating neurotransmission. This work aimed at assessing the influence of NO from different sources and respective intracellular pathways on sympathetic neurotransmission, in two vascular beds. Electrically-evoked [3H]-noradrenaline release was assessed in rat mesenteric and tail arteries in the presence of NO donors or endothelial/neuronal nitric oxide synthase (NOS inhibitors. The influence of NO on adenosine-mediated effects was also studied using selective antagonists for adenosine receptors subtypes. Location of neuronal NOS (nNOS was investigated by immunohistochemistry (with specific antibodies for nNOS and for Schwann cells and Confocal Microscopy. Results indicated that: 1 in mesenteric arteries, noradrenaline release was reduced by NO donors and it was increased by nNOS inhibitors; the effect of NO donors was only abolished by the adenosine A1 receptors antagonist; 2 in tail arteries, noradrenaline release was increased by NO donors and it was reduced by eNOS inhibitors; adenosine receptors antagonists were devoid of effect; 3 confocal microscopy showed nNOS staining in adventitial cells, some co-localized with Schwann cells. nNOS staining and its co-localization with Schwann cells were significantly lower in tail compared to mesenteric arteries. In conclusion, in mesenteric arteries, nNOS, mainly located in Schwann cells, seems to be the main source of NO influencing perivascular sympathetic neurotransmission with an inhibitory effect, mediated by adenosine A1 receptors activation. Instead, in tail arteries endothelial NO seems to play a more relevant role and has a facilitatory effect, independent of adenosine receptors activation.

  12. Influence of the cardiac myosin hinge region on contractile activity.

    OpenAIRE

    Margossian, S S; Krueger, J W; Sellers, J R; Cuda, G; Caulfield, J B; Norton, P.; Slayter, H. S.

    1991-01-01

    The participation of cardiac myosin hinge in contractility was investigated by in vitro motility and ATPase assays and by measurements of sarcomere shortening. The effect on contractile activity was analyzed using an antibody directed against a 20-amino acid peptide within the hinge region of myosin. This antibody bound specifically at the hinge at a distance of 55 nm from the S1/S2 junction, was specific to human, dog, and rat cardiac myosins, did not crossreact with gizzard or skeletal myos...

  13. Hypothalamic Paraventricular and Arcuate Nuclei Contribute to Elevated Sympathetic Nerve Activity in Pregnant Rats: Roles of Neuropeptide Y and α-Melanocyte-Stimulating Hormone.

    Science.gov (United States)

    Shi, Zhigang; Cassaglia, Priscila A; Gotthardt, Laura C; Brooks, Virginia L

    2015-12-01

    Pregnancy increases sympathetic nerve activity (SNA), but the mechanisms are unknown. Here, we investigated the contributions of the hypothalamic paraventricular and arcuate nuclei in α-chloralose-anesthetized pregnant and nonpregnant rats. Baseline arterial pressure (AP) was lower, and heart rate (HR), lumbar sympathetic activity, and splanchnic SNA were higher in pregnant rats compared with nonpregnant rats. Inhibition of the paraventricular nucleus via bilateral muscimol nanoinjections decreased AP and HR more in pregnant rats than in nonpregnant rats and decreased lumbar SNA only in pregnant rats. Similarly, after arcuate muscimol nanoninjections, the decreases in AP, HR, and lumbar, renal, and splanchnic sympathetic nerve activities were greater in pregnant rats than in nonpregnant rats. Major arcuate neuronal groups that project to the paraventricular nucleus express inhibitory neuropeptide Y (NPY) and excitatory α-melanocyte-stimulating hormone. Inhibition of paraventricular melanocortin 3/4 receptors with SHU9119 also decreased AP, HR, and lumbar SNA in pregnant rats but not in nonpregnant rats. Conversely, paraventricular nucleus NPY expression was reduced in pregnant animals, and although blockade of paraventricular NPY Y1 receptors increased AP, HR, and lumbar sympathetic activity in nonpregnant rats, it had no effects in pregnant rats. Yet, the sympathoinhibitory, depressor, and bradycardic effects of paraventricular NPY nanoinjections were similar between groups. In conclusion, the paraventricular and arcuate nuclei contribute to increased basal SNA during pregnancy, likely due in part to decreased tonic NPY inhibition and increased tonic α-melanocyte-stimulating hormone excitation of presympathetic neurons in the paraventricular nucleus.

  14. Hypothalamic Paraventricular and Arcuate Nuclei Contribute to Elevated Sympathetic Nerve Activity in Pregnant Rats: Roles of Neuropeptide Y and α-Melanocyte-Stimulating Hormone.

    Science.gov (United States)

    Shi, Zhigang; Cassaglia, Priscila A; Gotthardt, Laura C; Brooks, Virginia L

    2015-12-01

    Pregnancy increases sympathetic nerve activity (SNA), but the mechanisms are unknown. Here, we investigated the contributions of the hypothalamic paraventricular and arcuate nuclei in α-chloralose-anesthetized pregnant and nonpregnant rats. Baseline arterial pressure (AP) was lower, and heart rate (HR), lumbar sympathetic activity, and splanchnic SNA were higher in pregnant rats compared with nonpregnant rats. Inhibition of the paraventricular nucleus via bilateral muscimol nanoinjections decreased AP and HR more in pregnant rats than in nonpregnant rats and decreased lumbar SNA only in pregnant rats. Similarly, after arcuate muscimol nanoninjections, the decreases in AP, HR, and lumbar, renal, and splanchnic sympathetic nerve activities were greater in pregnant rats than in nonpregnant rats. Major arcuate neuronal groups that project to the paraventricular nucleus express inhibitory neuropeptide Y (NPY) and excitatory α-melanocyte-stimulating hormone. Inhibition of paraventricular melanocortin 3/4 receptors with SHU9119 also decreased AP, HR, and lumbar SNA in pregnant rats but not in nonpregnant rats. Conversely, paraventricular nucleus NPY expression was reduced in pregnant animals, and although blockade of paraventricular NPY Y1 receptors increased AP, HR, and lumbar sympathetic activity in nonpregnant rats, it had no effects in pregnant rats. Yet, the sympathoinhibitory, depressor, and bradycardic effects of paraventricular NPY nanoinjections were similar between groups. In conclusion, the paraventricular and arcuate nuclei contribute to increased basal SNA during pregnancy, likely due in part to decreased tonic NPY inhibition and increased tonic α-melanocyte-stimulating hormone excitation of presympathetic neurons in the paraventricular nucleus. PMID:26483343

  15. Hypotensive effect of taurine. Possible involvement of the sympathetic nervous system and endogenous opiates.

    OpenAIRE

    Fujita, T.; Sato, Y.

    1988-01-01

    We studied the role of diminished sympathetic nervous system (SNS) activity and endogenous opiate activation in the hypotensive action of taurine, a sulfur amino acid, in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Supplementation of taurine could prevent the development of DOCA-salt hypertension in rats, but failed to change blood pressure in vehicle-treated control rats. Cardiac NE turnover, which was determined from the rate of decline of tissue NE concentration after the ad...

  16. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    LENUS (Irish Health Repository)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient\\'s cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  17. Enhanced sympathetic nerve activity induced by neonatal colon inflammation induces gastric hypersensitivity and anxiety-like behavior in adult rats.

    Science.gov (United States)

    Winston, John H; Sarna, Sushil K

    2016-07-01

    Gastric hypersensitivity (GHS) and anxiety are prevalent in functional dyspepsia patients; their underlying mechanisms remain unknown largely because of lack of availability of live visceral tissues from human subjects. Recently, we demonstrated in a preclinical model that rats subjected to neonatal colon inflammation show increased basal plasma norepinephrine (NE), which contributes to GHS through the upregulation of nerve growth factor (NGF) expression in the gastric fundus. We tested the hypothesis that neonatal colon inflammation increases anxiety-like behavior and sympathetic nervous system activity, which upregulates the expression of NGF to induce GHS in adult life. Chemical sympathectomy, but not adrenalectomy, suppressed the elevated NGF expression in the fundus muscularis externa and GHS. The measurement of heart rate variability showed a significant increase in the low frequency-to-high frequency ratio in GHS vs. the control rats. Stimulus-evoked release of NE from the fundus muscularis externa strips was significantly greater in GHS than in the control rats. Tyrosine hydroxylase expression was increased in the celiac ganglia of the GHS vs. the control rats. We found an increase in trait but not stress-induced anxiety-like behavior in GHS rats in an elevated plus maze. We concluded that neonatal programming triggered by colon inflammation upregulates tyrosine hydroxylase in the celiac ganglia, which upregulates the release of NE in the gastric fundus muscularis externa. The increase of NE release from the sympathetic nerve terminals concentration dependently upregulates NGF, which proportionately increases the visceromotor response to gastric distention. Neonatal programming concurrently increases anxiety-like behavior in GHS rats. PMID:27151940

  18. OBJECTIVE EVALUATION OF CARDIAC AUTONOMIC ACTIVITY IN DIFFERENT PHASES OF MENSTRUAL CYCLE

    Directory of Open Access Journals (Sweden)

    Srujana

    2015-01-01

    Full Text Available A wide spectrum of biological function is regulated by the cyclic changes in estrogen and progesterone levels during regular menstrual cycle. However limited literature is available concerning the relationship of these hormones and cardiac autonomic activity. In the present study, we hypothesize that there would be heart rate variability during different phases of menstrual cycle, which can be attributed to the effect of ovarian steroids on cardiovascular function in women. The aim of the study is to compare the c ardiac autonomic activity in the different phases of menstrual cycle ( M enstrual, follicular and luteal phases using heart rate variability. The objective is to establish a physiological correlation between the cardiac autonomic activity and different phas es of menstrual cycle. The study was conducted in 48 regularly menstruating young female, of age group 18 - 30yrs, in the Upgraded Department of Physiology, Osmania medical college, from December 2011 to August 2013, using LABCHART software provided by ADLAB S. The power spectral analysis of HRV was used to calculate low frequency(LF , high frequency (HF component and their ratio (LF/HF during menstrual (2±1 days, follicular(11±1 day and luteal phases (20±1day from the first day of bleeding. Results showe d a significant increase was noted in low frequency component in luteal phase compared to follicular phase (p=0.000, whereas, a tendency for increase in high frequency component was observed in follicular phase (p=0.004. Furthermore, LF/HF was significan tly higher in luteal phase than in the follicular phase (p=0.000 indicating an increased sympathetic activity. The conclusion is regulation of autonomic tone is modified during menstrual cycle. The alteration in the balance of ovarian hormones might be re sponsible for these changes.

  19. Relationship between duration of illness and cardiac autonomic nervous activity in anorexia nervosa

    OpenAIRE

    Nakai, Yoshikatsu; Fujita, Masatoshi; Nin, Kazuko; Noma, Shun’ichi; Teramukai, Satoshi

    2015-01-01

    Background The mortality rate associated with anorexia nervosa (AN) is high, and death is mainly attributable to cardiac events. A wide range of autonomic nervous system disturbances may be mechanisms underlying the increased cardiovascular mortality and sudden death of patients with AN. Heart rate variability (HRV) has been proven to be a reliable noninvasive method for quantitative assessment of sympathetic and parasympathetic regulation of heart rate (HR). The longer the duration of illnes...

  20. Relationship between duration of illness and cardiac autonomic nervous activity in anorexia nervosa

    OpenAIRE

    Nakai, Yoshikatsu; Fujita, Masatoshi; Nin, Kazuko; Noma, Shun'ichi; Teramukai, Satoshi

    2015-01-01

    Background: The mortality rate associated with anorexia nervosa (AN) is high, and death is mainly attributable to cardiac events. A wide range of autonomic nervous system disturbances may be mechanisms underlying the increased cardiovascular mortality and sudden death of patients with AN. Heart rate variability (HRV) has been proven to be a reliable noninvasive method for quantitative assessment of sympathetic and parasympathetic regulation of heart rate (HR). The longer the duration of illne...

  1. Effects of nitric oxide synthase inhibition on sympathetically-mediated tachycardia

    Science.gov (United States)

    Whalen, E. J.; Johnson, A. K.; Lewis, S. J.

    1999-01-01

    The aim of the present study was to determine whether inhibition of nitric oxide (NO) synthesis directly alters the tachycardia produced by sympathetically-derived norepinephrine. The NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME; 50 micromol/kg, i.v.), produced a marked rise in mean arterial blood pressure. This pressor response was associated with a fall in heart rate which involved the withdrawal of cardiac sympathetic nerve activity. The NO-donor, sodium nitroprusside (5 microg/kg, i.v.), produced a pronounced fall in mean arterial blood pressure but only a minor increase in heart rate. The beta-adrenoceptor agonist, isoproterenol (0.5 micromol/kg, i.v.), and the membrane-permeable cAMP analogue, 8-(4-chlorophenylthiol)-cAMP (10 micromol/kg, i.v.), produced falls in mean arterial blood pressure and pronounced increases in heart rate. The indirectly acting sympathomimetic agent, tyramine (0.5 mg/kg, i.v.), produced a pressor response and a tachycardia. The effects of sodium nitroprusside, tyramine, isoproterenol and 8-(4-chlorophenylthiol)-cAMP on mean arterial blood pressure were not markedly affected by L-NAME. However, the tachycardia produced by these agents was considerably exaggerated in the presence of this NO synthesis inhibitor. These findings suggest that L-NAME potentiates the tachycardia produced by sympathetically-derived norepinephrine. The increased responsiveness to norepinephrine may involve (i) a rapid up-regulation of cardiac beta1-adrenoceptors and cAMP signaling in cardiac pacemaker cells due to the loss of the inhibitory influence of cardiac NO, and (ii) the up-regulation of beta1-adrenoceptor-mediated signal transduction processes in response to the L-NAME-induced withdrawal of cardiac sympathetic nerve activity.

  2. Sympathetic nervous dysregulation in the absence of systolic left ventricular dysfunction in a rat model of insulin resistance with hyperglycemia

    Directory of Open Access Journals (Sweden)

    Suuronen Erik J

    2011-08-01

    Full Text Available Abstract Background Diabetes mellitus is strongly associated with cardiovascular dysfunction, derived in part from impairment of sympathetic nervous system signaling. Glucose, insulin, and non-esterified fatty acids are potent stimulants of sympathetic activity and norepinephrine (NE release. We hypothesized that sustained hyperglycemia in the high fat diet-fed streptozotocin (STZ rat model of sustained hyperglycemia with insulin resistance would exhibit progressive sympathetic nervous dysfunction in parallel with deteriorating myocardial systolic and/or diastolic function. Methods Cardiac sympathetic nervous integrity was investigated in vivo via biodistribution of the positron emission tomography radiotracer and NE analogue [11C]meta-hydroxyephedrine ([11C]HED. Cardiac systolic and diastolic function was evaluated by echocardiography. Plasma and cardiac NE levels and NE reuptake transporter (NET expression were evaluated as correlative measurements. Results The animal model displays insulin resistance, sustained hyperglycemia, and progressive hypoinsulinemia. After 8 weeks of persistent hyperglycemia, there was a significant 13-25% reduction in [11C]HED retention in myocardium of STZ-treated hyperglycemic but not euglycemic rats as compared to controls. There was a parallel 17% reduction in immunoblot density for NE reuptake transporter, a 1.2 fold and 2.5 fold elevation of cardiac and plasma NE respectively, and no change in sympathetic nerve density. No change in ejection fraction or fractional area change was detected by echocardiography. Reduced heart rate, prolonged mitral valve deceleration time, and elevated transmitral early to atrial flow velocity ratio measured by pulse-wave Doppler in hyperglycemic rats suggest diastolic impairment of the left ventricle. Conclusions Taken together, these data suggest that sustained hyperglycemia is associated with elevated myocardial NE content and dysregulation of sympathetic nervous system

  3. Effects of 12 months continuous positive airway pressure on sympathetic activity related brainstem function and structure in obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    Luke Anthony Henderson

    2016-03-01

    Full Text Available Muscle sympathetic nerve activity (MSNA is greatly elevated in patients with obstructive sleep apnoea (OSA during normoxic daytime wakefulness. Increased MSNA is a precursor to hypertension and elevated cardiovascular morbidity and mortality. However, the mechanisms underlying the high MSNA in OSA are not well understood. In this study we used concurrent microneurography and magnetic resonance imaging to explore MSNA-related brainstem activity changes and anatomical changes in 15 control and 15 subjects with OSA prior to and following 6 and 12 months of continuous positive airway pressure (CPAP treatment. We found that 6 and 12 months of CPAP treatment significantly reduced the elevated resting MSNA in individuals with OSA. Furthermore, this MSNA reduction was associated with restoration of MSNA-related activity and structural changes in the medullary raphe, rostral ventrolateral medulla, dorsolateral pons and ventral midbrain. This restoration occurred after 6 months of CPAP treatment and was maintained following 12 months CPAP. These findings show that continual CPAP treatment is an effective long-term treatment for elevated MNSA likely due to its effects on restoring brainstem structure and function.

  4. The sensitivity of neurons with non-periodic activity to sympathetic stimulation in rat injured dorsal root ganglion

    Institute of Scientific and Technical Information of China (English)

    Hong-Jun YANG; San-Jue HU; Pu-Lin GONG; Jian-Hong DUAN

    2006-01-01

    Objective The relationship between firing pattern and sensitivity of neurons was studied in chronically compressed dorsal root ganglion (DRG) neurons and the Hindmarsh-Rose (HR) neuronal model. Methods Spontaneous activities from single fibers of chronically compressed DRG neurons in rats were recorded, and divided into periodic and non-periodic firing patterns. The sensitivity of the two kinds of firing pattern neuron to sympathetic stimulation (SS)was compared. Result It was found that 27.3% of periodic firing neurons and 93.2% of non-periodic firing neurons responded to SS respectively ( periodic vs non-periodic, P < 0.01 ). The responses to SS with different stimulation time were greater non-periodic firing neurons than periodic firing neurons (P < 0.01 ). The non-periodic firing neurons obviously responded to SS. After the firing pattern of these neurons transformed to periodic firing pattern, their responses to SS disappeared or decreased obviously. The HR neuronal model exhibited a significantly greater response to perturbation in non-periodic (chaotic) firing pattern than in periodic firing pattern. Conclusion The non-periodic firing neurons with deterministic chaos are more sensitive to external stimuli than the periodic firing neurons.

  5. Arterial baroreceptor reflex control of renal sympathetic nerve activity following chronic myocardial infarction in male, female, and ovariectomized female rats.

    Science.gov (United States)

    Pinkham, Maximilian I; Whalley, Gillian A; Guild, Sarah-Jane; Malpas, Simon C; Barrett, Carolyn J

    2015-07-15

    There is controversy regarding whether the arterial baroreflex control of renal sympathetic nerve activity (SNA) in heart failure is altered. We investigated the impact of sex and ovarian hormones on changes in the arterial baroreflex control of renal SNA following a chronic myocardial infarction (MI). Renal SNA and arterial pressure were recorded in chloralose-urethane anesthetized male, female, and ovariectomized female (OVX) Wistar rats 6-7 wk postsham or MI surgery. Animals were grouped according to MI size (sham, small and large MI). Ovary-intact females had a lower mortality rate post-MI (24%) compared with both males (38%) and OVX (50%) (P renal SNA. As a result, the male large MI group (49 ± 6 vs. 84 ± 5% in male sham group) and OVX large MI group (37 ± 3 vs. 75 ± 5% in OVX sham group) displayed significantly reduced arterial baroreflex range of control of normalized renal SNA (P renal SNA was unchanged regardless of MI size. In males and OVX there was a significant, positive correlation between left ventricle (LV) ejection fraction and arterial baroreflex range of control of normalized renal SNA, but not absolute renal SNA, that was not evident in ovary-intact females. The current findings demonstrate that the arterial baroreflex control of renal SNA post-MI is preserved in ovary-intact females, and the state of left ventricular dysfunction significantly impacts on the changes in the arterial baroreflex post-MI.

  6. Sympathetic reflex control of blood flow in human peripheral tissues

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    Sympathetic vasoconstrictor reflexes are essential for the maintenance of arterial blood pressure in upright position. It has been generally believed that supraspinal sympathetic vasoconstrictor reflexes elicited by changes in baroreceptor activity play an important role. Recent studies on human ...... to collision of normodromically and antidromically conducted impulses in efferent sympathetic vasoconstrictor fibers. The evidence obtained suggests that sympathetic vasoconstrictor reflexes to postural changes are complex and highly differentiated....

  7. Evaluation of cardiac blood blow, metabolism and sympathetic nerve function in patients with cardiac failure using PET and SPECT. Prognostic diagnosis based on the analysis of aggravating factors of the disease

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Yoshio; Shimozu, Junko; Yasumura, Yoshio; Nagatani, Kenzo; Miyatake, Kunio [National Cardiovascular Center, Suita, Osaka (Japan)

    1998-02-01

    Focusing on the failure of energy metabolism, which is assumed to be attributed to the cardiac muscle disorder of a patient with cardiac failure, the characteristics and diagnostic significance of the metabolic disorders of cadiac muscles were investigated in those patients. The diagnostic efficacy of {beta}-methyl iodophenyl pentadecanoic acid (BMIPP) which is a imaging agent for lipid metabolism in the cardiac muscle was assessed in the clinical states of cardiac failure due to pulmonary hypertension. Even if there was a considerable increase in the mean pulmonary arterial pressure (mPAP), the initial accumulation of BMIPP linearly increased, similarly to the increase in the accumulation of MIBI, a blood flow agent. The initial accumulation of BMIPP was thought to reflect a thicken cardiac muscle and/or increased blood flow. Also, its washing-out rate was suggested to be usable as an clinical indicator to estimate the loading of ventricular pressure. (M.N.)

  8. A voltage-activated proton current in human cardiac fibroblasts

    International Nuclear Information System (INIS)

    A voltage-activated proton current in human cardiac fibroblasts, measured using the whole-cell recording configuration of the patch-clamp technique, is reported. Increasing the pH of the bathing solution shifted the current activation threshold to more negative potentials and increased both the current amplitude and its rate of activation. Changing the pH gradient by one unit caused a 51 mV shift in the reversal potential of the current, demonstrating a high selectivity for protons of the channel carrying the current. Extracellularly applied Zn2+ reversibly inhibited the current. Activation of the current contributes to the resting membrane conductance under conditions of intracellular acidosis. It is proposed that this current in cardiac fibroblasts is involved in the regulation of the intracellular pH and the membrane potential under physiological conditions as well as in response to pathological conditions such as ischemia

  9. Sympathetic nervous activity decreases during head-down bed rest but not during microgravity

    DEFF Research Database (Denmark)

    Christensen, Niels J; Heer, Martina; Ivanova, Krassimira;

    2005-01-01

    We tested the hypothesis that sympathoadrenal activity in humans is low during spaceflight and that this effect can be simulated by head-down bed rest (HDBR). Platelet norepinephrine and epinephrine were measured as indexes of long-term changes in sympathoadrenal activity. Ten normal healthy subj...

  10. Skeletal muscle reflex-mediated changes in sympathetic nerve activity are abnormal in spontaneously hypertensive rats

    OpenAIRE

    Mizuno, Masaki; Murphy, Megan N.; Mitchell, Jere H.; Smith, Scott A.

    2011-01-01

    In hypertension, the blood pressure response to exercise is exaggerated. We demonstrated previously that this heightened pressor response to physical activity is mediated by an overactive skeletal muscle exercise pressor reflex (EPR), with important contributions from its metaboreflex and mechanoreflex components. However, the mechanisms driving the abnormal blood pressure response to EPR activation are largely unknown. Recent evidence in humans suggests that the muscle metaboreflex partially...

  11. Vestibular modulation of muscle sympathetic nerve activity by the utricle during sub-perceptual sinusoidal linear acceleration in humans.

    Science.gov (United States)

    Hammam, Elie; Hau, Chui Luen Vera; Wong, Kwok-Shing; Kwok, Kenny; Macefield, Vaughan G

    2014-04-01

    We assessed the capacity for the vestibular utricle to modulate muscle sympathetic nerve activity (MSNA) during sinusoidal linear acceleration at amplitudes extending from imperceptible to clearly perceptible. Subjects (n = 16) were seated in a sealed room, eliminating visual cues, mounted on a linear motor that could deliver peak sinusoidal accelerations of 30 mG in the antero-posterior direction. Subjects sat on a padded chair with their neck and head supported vertically, thereby minimizing somatosensory cues, facing the direction of motion in the anterior direction. Each block of sinusoidal motion was applied at a time unknown to subjects and in a random order of amplitudes (1.25, 2.5, 5, 10, 20 and 30 mG), at a constant frequency of 0.2 Hz. MSNA was recorded via tungsten microelectrodes inserted into muscle fascicles of the common peroneal nerve. Subjects used a linear potentiometer aligned to the axis of motion to indicate any perceived movement, which was compared with the accelerometer signal of actual room movement. On average, 67% correct detection of movement did not occur until 6.5 mG, with correct knowledge of the direction of movement at ~10 mG. Cross-correlation analysis revealed potent sinusoidal modulation of MSNA even at accelerations subjects could not perceive (1.25-5 mG). The modulation index showed a positive linear increase with acceleration amplitude, such that the modulation was significantly higher (25.3 ± 3.7%) at 30 mG than at 1.25 mG (15.5 ± 1.2%). We conclude that selective activation of the vestibular utricle causes a pronounced modulation of MSNA, even at levels well below perceptual threshold, and provides further evidence in support of the importance of vestibulosympathetic reflexes in human cardiovascular control. PMID:24504198

  12. Interactions between cardiac, respiratory, and brain activity in humans

    Science.gov (United States)

    Musizza, Bojan; Stefanovska, Aneta

    2005-05-01

    The electrical activity of the heart (ECG), respiratory function and electric activity of the brain (EEG) were simultaneously recorded in conscious, healthy humans. Instantaneous frequencies of the heart beat, respiration and α-waves were then determined from 30-minutes recordings. The instantaneous cardiac frequency was defined as the inverse value of the time interval between two consecutive R-peaks. The instantaneous respiratory frequency was obtained from recordings of the excursions of thorax by application of the Hilbert transform. To obtain the instantaneous frequency of α-waves, the EEG signal recorded from the forehead was first analysed using the wavelet transform. Then the frequency band corresponding to α-waves was extracted and the Hilbert transform applied. Synchronization analysis was performed and the direction of coupling was ascertained, using pairs of instantaneous frequencies in each case. It is shown that the systems are weakly bidirectionally coupled. It was confirmed that, in conscious healthy humans, respiration drives cardiac activity. We also demonstrate from these analyses that α-activity drives both respiration and cardiac activity.

  13. Snoring, sympathetic activity and cardiovascular risk factors in a 70 year old population

    DEFF Research Database (Denmark)

    Jennum, P; Schultz-Larsen, K; Christensen, Niels Juel

    1993-01-01

    In order to describe the relation between snoring, cardiovascular risk factors, metabolic factors and sympathetitic activity, 804 70-year-old males and females were classified according to snoring habits and life-style factors (alcohol and tobacco consumption), blood pressure, body mass index (BMI...... between snoring and blood pressure ceased; only systolic blood pressure was associated with snoring (p year-old population, snoring is associated with gender...

  14. Modulation of transmission in rat sympathetic ganglia by activation of presynaptic alpha- and beta-adrenoceptors.

    OpenAIRE

    Medgett, I.C.

    1983-01-01

    1 Conditions under which transmission in rat isolated superior cervical ganglia may be affected by activation of presynaptic alpha- and beta-adrenoceptors have been investigated by means of an extracellular recording method. 2 Clonidine caused a small hyperpolarization of the ganglia (mean EC50 approximately 2 nM) in unstimulated preparations; with continuous preganglionic stimulation at 0.2 Hz, clonidine markedly decreased the height of the compound action potential (mean EC50 approximately ...

  15. A Model of Blood Pressure, Heart Rate, and Vaso-Vagal Responses Produced by Vestibulo-Sympathetic Activation.

    Science.gov (United States)

    Raphan, Theodore; Cohen, Bernard; Xiang, Yongqing; Yakushin, Sergei B

    2016-01-01

    Blood Pressure (BP), comprised of recurrent systoles and diastoles, is controlled by central mechanisms to maintain blood flow. Periodic behavior of BP was modeled to study how peak amplitudes and frequencies of the systoles are modulated by vestibular activation. The model was implemented as a relaxation oscillator, driven by a central signal related to Desired BP. Relaxation oscillations were maintained by a second order system comprising two integrators and a threshold element in the feedback loop. The output signal related to BP was generated as a nonlinear function of the derivative of the first state variable, which is a summation of an input related to Desired BP, feedback from the states, and an input from the vestibular system into one of the feedback loops. This nonlinear function was structured to best simulate the shapes of systoles and diastoles, the relationship between BP and Heart Rate (HR) as well as the amplitude modulations of BP and Pulse Pressure. Increases in threshold in one of the feedback loops produced lower frequencies of HR, but generated large pulse pressures to maintain orthostasis, without generating a VasoVagal Response (VVR). Pulse pressures were considerably smaller in the anesthetized rats than during the simulations, but simulated pulse pressures were lowered by including saturation in the feedback loop. Stochastic changes in threshold maintained the compensatory Baroreflex Sensitivity. Sudden decreases in Desired BP elicited non-compensatory VVRs with smaller pulse pressures, consistent with experimental data. The model suggests that the Vestibular Sympathetic Reflex (VSR) modulates BP and HR of an oscillating system by manipulating parameters of the baroreflex feedback and the signals that maintain the oscillations. It also shows that a VVR is generated when the vestibular input triggers a marked reduction in Desired BP. PMID:27065779

  16. A model of blood pressure, heart rate, and vaso-vagal responses produced by vestibulo-sympathetic activation

    Directory of Open Access Journals (Sweden)

    Theodore eRaphan

    2016-03-01

    Full Text Available Blood Pressure (BP, comprised of recurrent systoles and diastoles, is controlled by central mechanisms to maintain blood flow. Periodic behavior of BP was modeled to study how peak amplitudes and frequencies of the systoles are modulated by vestibular activation. The model was implemented as a relaxation oscillator, driven by a central signal related to Desired BP. Relaxation oscillations were maintained by a second order system comprising two integrators and a threshold element in the feedback loop. The output signal related to BP was generated as a nonlinear function of the derivative of the first state variable, which is a summation of an input related to desired BP, feedback from the states, and an input from the vestibular system into one of one of the feedback loops. This nonlinear function was structured to best simulate the shapes of systoles and diastoles, the relationship between BP and Heart Rate (HR as well as the amplitude modulations of BP and Pulse Pressure. Increases in threshold in one of the feedback loops produced lower frequencies of HR, but generated large pulse pressures to maintain orthostasis, without generating a VasoVagal Response (VVR. Pulse pressures were considerably smaller in the anesthetized rats than during the simulations, but simulated pulse pressures were lowered by including saturation in the feedback loop. Stochastic changes in Threshold maintained the compensatory Baroreflex Sensitivity. Sudden decreases in Desired BP elicited non-compensatory VVRs with smaller pulse pressures, consistent with experimental data. The model suggests that the Vestibular Sympathetic Reflex modulates BP and HR of an oscillating system by manipulating parameters of the baroreflex feedback and the signals that maintain the oscillations. It also shows that a VVR is generated when the vestibular input triggers a marked reduction in Desired BP.

  17. Arterial baroreceptor reflex control of renal sympathetic nerve activity following chronic myocardial infarction in male, female, and ovariectomized female rats.

    Science.gov (United States)

    Pinkham, Maximilian I; Whalley, Gillian A; Guild, Sarah-Jane; Malpas, Simon C; Barrett, Carolyn J

    2015-07-15

    There is controversy regarding whether the arterial baroreflex control of renal sympathetic nerve activity (SNA) in heart failure is altered. We investigated the impact of sex and ovarian hormones on changes in the arterial baroreflex control of renal SNA following a chronic myocardial infarction (MI). Renal SNA and arterial pressure were recorded in chloralose-urethane anesthetized male, female, and ovariectomized female (OVX) Wistar rats 6-7 wk postsham or MI surgery. Animals were grouped according to MI size (sham, small and large MI). Ovary-intact females had a lower mortality rate post-MI (24%) compared with both males (38%) and OVX (50%) (P < 0.05). Males and OVX with large MI, but not small MI, displayed an impaired ability of the arterial baroreflex to inhibit renal SNA. As a result, the male large MI group (49 ± 6 vs. 84 ± 5% in male sham group) and OVX large MI group (37 ± 3 vs. 75 ± 5% in OVX sham group) displayed significantly reduced arterial baroreflex range of control of normalized renal SNA (P < 0.05). In ovary-intact females, arterial baroreflex control of normalized renal SNA was unchanged regardless of MI size. In males and OVX there was a significant, positive correlation between left ventricle (LV) ejection fraction and arterial baroreflex range of control of normalized renal SNA, but not absolute renal SNA, that was not evident in ovary-intact females. The current findings demonstrate that the arterial baroreflex control of renal SNA post-MI is preserved in ovary-intact females, and the state of left ventricular dysfunction significantly impacts on the changes in the arterial baroreflex post-MI. PMID:25994953

  18. Absence of arterial baroreflex modulation of skin sympathetic activity and sweat rate during whole-body heating in humans

    Science.gov (United States)

    Wilson, T. E.; Cui, J.; Crandall, C. G.

    2001-01-01

    1. Prior findings suggest that baroreflexes are capable of modulating skin blood flow, but the effects of baroreceptor loading/unloading on sweating are less clear. Therefore, this project tested the hypothesis that pharmacologically induced alterations in arterial blood pressure in heated humans would lead to baroreflex-mediated changes in both skin sympathetic nerve activity (SSNA) and sweat rate. 2. In seven subjects mean arterial blood pressure was lowered (approximately 8 mmHg) and then raised (approximately 13 mmHg) by bolus injections of sodium nitroprusside and phenylephrine, respectively. Moreover, in a separate protocol, arterial blood pressure was reduced via steady-state administration of sodium nitroprusside. In both normothermia and heat-stress conditions the following responses were monitored: sublingual and mean skin temperatures, heart rate, beat-by-beat blood pressure, skin blood flow (laser-Doppler flowmetry), local sweat rate and SSNA (microneurography from peroneal nerve). 3. Whole-body heating increased skin and sublingual temperatures, heart rate, cutaneous blood flow, sweat rate and SSNA, but did not change arterial blood pressure. Heart rate was significantly elevated (from 74 +/- 3 to 92 +/- 4 beats x min(-1); P < 0.001) during bolus sodium nitroprusside-induced reductions in blood pressure, and significantly reduced (from 92 +/- 4 to 68 +/- 4 beats x min(-1); P < 0.001) during bolus phenylephrine-induced elevations in blood pressure, thereby demonstrating normal baroreflex function in these subjects. 4. Neither SSNA nor sweat rate was altered by rapid (bolus infusion) or sustained (steady-state infusion) changes in blood pressure regardless of the thermal condition. 5. These data suggest that SSNA and sweat rate are not modulated by arterial baroreflexes in normothermic or moderately heated individuals.

  19. Foxo1 regulates Dbh expression and the activity of the sympathetic nervous system in vivo

    Directory of Open Access Journals (Sweden)

    Daisuke Kajimura

    2014-10-01

    Full Text Available The transcription factor FoxO1 regulates multiple physiological processes. Here, we show that FoxO1 is highly expressed in neurons of the locus coeruleus and of various sympathetic ganglions, but not in the adrenal medulla. Consistent with this pattern of expression, mice lacking FoxO1 only in sympathetic neurons (FoxO1Dbh−/− display a low sympathetic tone without modification of the catecholamine content in the adrenal medulla. As a result, FoxO1Dbh−/− mice demonstrate an increased insulin secretion, improved glucose tolerance, low energy expenditure, and high bone mass. FoxO1 favors catecholamine synthesis because it is a potent regulator of the expression of Dbh that encodes the initial and rate-limiting enzyme in the synthesis of these neurotransmitters. By identifying FoxO1 as a transcriptional regulator of the sympathetic tone, these results advance our understanding of the control of some aspects of metabolism and of bone mass accrual.

  20. Incidence of Sudden Cardiac Death in a Young Active Population

    OpenAIRE

    Farioli, Andrea; Christophi, Costas A; Quarta, Candida Cristina; Kales, Stefanos N

    2015-01-01

    Background: Little is known about the burden of sudden cardiac death (SCD) among active, presumably healthy persons. We investigated the incidence of SCD among US male career firefighters. Methods and Results: All on-duty SCDs among US male career firefighters between 1998 and 2012 were identified from the US Fire Administration and the US National Institute for Occupational Safety and Health databases. Age-specific incidence rates (IRs) of SCD with 95% CIs were computed. A joinpoint model wa...

  1. Incidence of Sudden Cardiac Death in a Young Active Population

    OpenAIRE

    Farioli, Andrea; Christophi, Costas A; Quarta, Candida Cristina; Kales, Stefanos N

    2015-01-01

    Background Little is known about the burden of sudden cardiac death (SCD) among active, presumably healthy persons. We investigated the incidence of SCD among US male career firefighters. Methods and Results All on-duty SCDs among US male career firefighters between 1998 and 2012 were identified from the US Fire Administration and the US National Institute for Occupational Safety and Health databases. Age-specific incidence rates (IRs) of SCD with 95% CIs were computed. A joinpoint model was ...

  2. Influence of the cardiac myosin hinge region on contractile activity.

    Science.gov (United States)

    Margossian, S S; Krueger, J W; Sellers, J R; Cuda, G; Caulfield, J B; Norton, P; Slayter, H S

    1991-06-01

    The participation of cardiac myosin hinge in contractility was investigated by in vitro motility and ATPase assays and by measurements of sarcomere shortening. The effect on contractile activity was analyzed using an antibody directed against a 20-amino acid peptide within the hinge region of myosin. This antibody bound specifically at the hinge at a distance of 55 nm from the S1/S2 junction, was specific to human, dog, and rat cardiac myosins, did not crossreact with gizzard or skeletal myosin, and had no effect on ATPase activity of purified S1 and myofibrils. However, it completely suppressed the movement of actin filaments in in vitro motility assays and reduced active shortening of sarcomeres of skinned cardiac myocytes by half. Suppression of motion by the anti-hinge antibody may reflect a mechanical constraint imposed by the antibody upon the mobility of the S2 region of myosin. The results suggest that the steps in the mechanochemical energy transduction can be separately influenced through S2.

  3. Characterization of the hyperpolarization-activated chloride current in dissociated rat sympathetic neurons.

    Science.gov (United States)

    Clark, S; Jordt, S E; Jentsch, T J; Mathie, A

    1998-02-01

    1. Dissociated rat superior cervical ganglion (SCG) neurons have been shown to possess a hyperpolarization-activated inwardly rectifying chloride current. The current was not altered by changes in external potassium concentration, replacing external cations with NMDG (N-methyl-D-glucamine) or by addition of 10 mM caesium or barium ions. 2. The reversal potential of the current was altered by changing external anions. The anion selectivity of the current was Cl- > Br- > I- > cyclamate. All substituted permeant anions also blocked the current. 3. The current was blocked by DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid), 9AC (anthracene-9-carboxylic acid) and NPPB (5-nitro-2-(3-phenylpropylamino)benzoic acid) but was unaffected by SITS (4-acetamido-4'-isothiocyanatostilbene- 2,2'-disulphonic acid) and niflumic acid. The effective blockers were voltage dependent; DIDS and NPPB were more effective at depolarized potentials while 9AC was more effective at hyperpolarized potentials. 4. The current was enhanced by extracellular acidification and reduced by extracellular alkalinization. Reducing external osmolarity was without effect in conventional whole-cell recording but enhanced current amplitude in those perforated-patch recordings where little current was evident in control external solution. 5. The current in SCG neurons was blocked by external cadmium and zinc. ClC-2 chloride currents expressed in Xenopus oocytes were also sensitive to block by these divalent ions and by DIDS but the sensitivity of ClC-2 to block by cadmium ions was lower than that of the current in SCG neurons. 6. Reverse transcriptase-polymerase chain reaction (RT-PCR) experiments showed the presence of mRNA for ClC-2 in SCG neurons but not in rat cerebellar granule cells which do not possess a hyperpolarization-activated Cl- current. 7. The data suggest that ClC-2 may be functionally expressed in rat SCG neurons. This current may play a role in regulating the internal chloride

  4. Effect of cortisol on muscle sympathetic nerve activity in Pima Indians and Caucasians

    DEFF Research Database (Denmark)

    Vozarova, Barbora; Weyer, Christian; Snitker, Soren;

    2003-01-01

    . Although glucocorticoids inhibit SNS activity, Pima Indians are not hypercortisolemic compared with Caucasians. This does not exclude the possibility that the SNS is more responsive to an inhibitory effect of cortisol in the former than in the latter group. We measured fasting plasma ACTH and cortisol...... (metyrapone) followed by cortisol replacement (hydrocortisone) on plasma ACTH, cortisol, and MSNA. There were no ethnic differences in fasting plasma ACTH or cortisol, but MSNA adjusted for percent body fat was lower in Pimas than in Caucasians (P cortisol...... to a tonic inhibitory effect of cortisol. However, an acute release of cortisol is likely to more effectively contain sympathoexcitation during stress in Pima Indians than in Caucasians, which may be an important mechanism of cardioprotection in this Native American population....

  5. Clinical application of l-123 MlBG cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young [College of Medicine, Donga Univ., Busan (Korea, Republic of)

    2004-10-01

    Cardiac neurotransmission imaging allows in vivo assessment of presynaptic reuptake, neurotransmitter storage and postsynaptic receptors. Among the various neurotransmitter, I-123 MlBG is most available and relatively well-established. Metaiodobenzylguanidine (MIBG) is an analogue of the false neurotransmitter guanethidine. It is taken up to adrenergic neurons by uptake-1 mechanism as same as norepinephrine. As tagged with I-123, it can be used to image sympathetic function in various organs including heart with planar or SPECT techniques. I-123 MIBG imaging has a unique advantage to evaluate myocardial neuronal activity in which the heart has no significant structural abnormality or even no functional derangement measured with other conventional examination. In patients with cardiomyopathy and heart failure, this imaging has most sensitive technique to predict prognosis and treatment response of betablocker or ACE inhibitor. In diabetic patients, it allow very early detection of autonomic neuropathy. In patients with dangerous arrhythmia such as ventricular tachycardia or fibrillation, MIBG imaging may be only an abnormal result among various exams. In patients with ischemic heart disease, sympathetic derangement may be used as the method of risk stratification. In heart transplanted patients, sympathetic reinnervation is well evaluated. Adriamycin-induced cardiotoxicity is detected earlier than ventricular dysfunction with sympathetic dysfunction. Neurodegenerative disorder such as Parkinson's disease or dementia with Lewy bodies has also cardiac sympathetic dysfunction. Noninvasive assessment of cardiac sympathetic nerve activity with l-123 MlBG imaging may be improve understanding of the pathophysiology of cardiac disease and make a contribution to predict survival and therapy efficacy.

  6. Role of angiotensin AT2 receptors and nitric oxide in the cardiopulmonary baroreflex control of renal sympathetic nerve activity in anaesthetised rats

    OpenAIRE

    Abdulla, Mohammed H.; Johns, Edward J.

    2013-01-01

    This study investigated the role of AT2 receptor activation and the possible interaction with nitric oxide (NO) in low-pressure baroreceptor regulation of renal sympathetic nerve activity (RSNA). Renal sympatho-inhibition to a saline volume expansion (VEP, 0.25% bwt/min I.V. for 30 min) was studied following intracerebroventricular (i.c.v.) saline, CGP42112 (CGP, AT2 agonist), PD123319 (PD, AT2 antagonist) and losartan (AT1 antagonist), and then in combination with L-NAME (NO synthase inhibit...

  7. A comparison of sympathoadrenal activity and cardiac performance at rest and during exercise in patients with ventricular demand or atrial synchronous pacing.

    OpenAIRE

    Pehrsson, S K; Hjemdahl, P; Nordlander, R; Aström, H

    1988-01-01

    Cardiac sympathetic function was assessed by measuring the coronary sinus overflow of noradrenaline and dopamine at rest and during supine exercise in eight patients with high degree atrioventricular block treated with dual chamber pacemakers (DDD). Patients exercised (30-60 W) during both ventricular inhibited (VVI) and atrial synchronous (VAT) pacing. During exercise cardiac output increased less markedly in the VVI mode than in the VAT mode. The cardiac output response was entirely stroke ...

  8. Use-dependent loss of active sympathetic neurogenic vasodilation after nitric oxide synthase inhibition in conscious rats. Evidence for the presence of preformed stores of nitric oxide-containing factors

    Science.gov (United States)

    Davisson, R. L.; Shaffer, R. A.; Johnson, A. K.; Lewis, S. J.

    1996-01-01

    In this study, we examined whether air-jet stress-induced active sympathetic hindlimb vasodilation in conscious rats involves the release of preformed stores of nitric oxide-containing factors. We determined the effects of repeated episodes of air-jet stress (six episodes given 5 minutes apart) on mean arterial pressure and vascular resistances in the mesenteric bed and intact and sympathetically denervated hindlimb beds of conscious rats treated with saline or the nitric oxide synthesis inhibitor N omega-nitro-L-arginine methyl ester (L-NAME, 25 mumol/kg IV). In saline-treated rats, air-jet stress produced alerting behavior, minor changes in blood pressure, pronounced mesenteric vaso-constriction, and immediate and marked vasodilation in the sympathetically intact hindlimb but a minor vasodilation in the sympathetically denervated hindlimb. Each air-jet stress produced virtually identical responses. In L-NAME-treated rats, the first air-jet stress produced vasodilator responses in the sympathetically intact and sympathetically denervated hindlimbs that were similar to those in the saline-treated rats. However, each subsequent air-jet stress produced progressively smaller vasodilator responses in the sympathetically intact but not the sympathetically denervated hindlimb. There was no loss of air-jet stress-induced alerting behavior or mesenteric vasoconstriction, suggesting that L-NAME did not interfere with the central processing of the air-jet or the resultant changes in autonomic nerve activity. The progressive diminution of air-jet stress-induced vasodilation in the intact hindlimb of L-NAME-treated rats may be due to the use-dependent depletion of preformed stores of nitric oxide-containing factors that cannot be replenished in the absence of nitric oxide synthesis.

  9. Macrophage depletion suppresses sympathetic hyperinnervation following myocardial infarction

    OpenAIRE

    Wernli, G.; Hasan, W.; Bhattacherjee, A.; Rooijen, van, J.; Smith, P K

    2009-01-01

    Myocardial infarction induces sympathetic axon sprouting adjacent to the necrotic region, and this has been implicated in the etiology of arrhythmias resulting in sudden cardiac death. Previous studies show that nerve growth factor (NGF) is essential for enhanced post-infarct sympathetic sprouting, but the cell types necessary to supply this neurotrophic protein are unknown. The objective of the present study was to determine whether macrophages, which are known to synthesize NGF, are necessa...

  10. Differential effects of adrenergic antagonists (Carvedilol vs Metoprolol) on parasympathetic and sympathetic activity: a comparison of measures

    OpenAIRE

    Vinik, Aaron I.; Bloom, Heather L.; Colombo, Joe

    2014-01-01

    Background Cardiovascular autonomic neuropathy (CAN) is recognized as a significant health risk. Specific and sensitive measures of CAN are needed for early identification and treatment to avoid complications, preferably in the preclinical state. Objectives In this first of two articles, the patient cohort is described and two measures of autonomic function are reviewed: the traditional heart rate variability (HRV)-alone method and the newer parasympathetic and sympathetic (P&S) Method. These...

  11. Macaque cardiac physiology is sensitive to the valence of passively viewed sensory stimuli.

    Directory of Open Access Journals (Sweden)

    Eliza Bliss-Moreau

    Full Text Available Autonomic nervous system activity is an important component of affective experience. We demonstrate in the rhesus monkey that both the sympathetic and parasympathetic branches of the autonomic nervous system respond differentially to the affective valence of passively viewed video stimuli. We recorded cardiac impedance and an electrocardiogram while adult macaques watched a series of 300 30-second videos that varied in their affective content. We found that sympathetic activity (as measured by cardiac pre-ejection period increased and parasympathetic activity (as measured by respiratory sinus arrhythmia decreased as video content changes from positive to negative. These findings parallel the relationship between autonomic nervous system responsivity and valence of stimuli in humans. Given the relationship between human cardiac physiology and affective processing, these findings suggest that macaque cardiac physiology may be an index of affect in nonverbal animals.

  12. Quantification of cardiac autonomic nervous activities in ambulatory dogs by eliminating cardiac electric activities using cubic smoothing spline

    International Nuclear Information System (INIS)

    With the development of an implantable radio transmitter system, direct measurement of cardiac autonomic nervous activities (CANAs) became possible for ambulatory animals for a couple of months. However, measured CANAs include not only CANA but also cardiac electric activity (CEA) that can affect the quantification of CANAs. In this study, we propose a novel CEA removal method using moving standard deviation and cubic smoothing spline. This method consisted of two steps of detecting CEA segments and eliminating CEAs in detected segments. Using implanted devices, we recorded stellate ganglion nerve activity (SGNA), vagal nerve activity (VNA) and superior left ganglionated plexi nerve activity (SLGPNA) directly from four ambulatory dogs. The CEA-removal performance of the proposed method was evaluated and compared with commonly used high-pass filtration (HPF) for various heart rates and CANA amplitudes. Results tested with simulated CEA and simulated true CANA revealed stable and excellent performance of the suggested method compared to the HPF method. The averaged relative error percentages of the proposed method were less than 0.67%, 0.65% and 1.76% for SGNA, VNA and SLGPNA, respectively. (paper)

  13. [Changes in the activity of sympathetic-adrenal medullary system and hypothalamic-pituitary-adrenal system in humans exposed to psychogenic stressors and their effects on immunoreactivity].

    Science.gov (United States)

    Simić, Natasa

    2010-10-01

    This paper gives an account of the functioning of the two systems in different stress induced situations. The activation of the sympathetic-adrenal medullary system is accompanied by the release of catecholamines, while the increased activity of the hypothalamic-pituitary-adrenal system results in the increased release of corticosteroids, especially cortisol. The role of the sympathetic-adrenal medullary system was investigated in immunologic changes induced by laboratory stressors. In the real, as in laboratory conditions, the effects of different stressors on the level of cortisol were studied, as it is the final product of the hypothalamic-pituitary-adrenal system activity. Additional (negative) effects on the functioning of these systems could induce some variables, as an increased consumption of alcohol, smoking, and sleeping disorder. Furthermore, the methodological shortcomings and the selection of subjects in previous studies are discussed. Previous results are also discussed, such as the immunosuppressive effects of cortisol, as well as the mediator and moderator variables in relation to stress and immunoreactivity.

  14. Blockade of Rostral Ventrolateral Medulla (RVLM) Bombesin Receptor Type 1 Decreases Blood Pressure and Sympathetic Activity in Anesthetized Spontaneously Hypertensive Rats.

    Science.gov (United States)

    Pinto, Izabella S; Mourão, Aline A; da Silva, Elaine F; Camargo, Amanda S; Marques, Stefanne M; Gomes, Karina P; Fajemiroye, James O; da Silva Reis, Angela A; Rebelo, Ana C S; Ferreira-Neto, Marcos L; Rosa, Daniel A; Freiria-Oliveira, André H; Castro, Carlos H; Colombari, Eduardo; Colugnati, Diego B; Pedrino, Gustavo R

    2016-01-01

    Intrathecal injection of bombesin (BBS) promoted hypertensive and sympathoexcitatory effects in normotensive (NT) rats. However, the involvement of rostral ventrolateral medulla (RVLM) in these responses is still unclear. In the present study, we investigated: (1) the effects of BBS injected bilaterally into RVLM on cardiorespiratory and sympathetic activity in NT and spontaneously hypertensive rats (SHR); (2) the contribution of RVLM BBS type 1 receptors (BB1) to the maintenance of hypertension in SHR. Urethane-anesthetized rats (1.2 g · kg(-1), i.v.) were instrumented to record mean arterial pressure (MAP), diaphragm (DIA) motor, and renal sympathetic nerve activity (RSNA). In NT rats and SHR, BBS (0.3 mM) nanoinjected into RVLM increased MAP (33.9 ± 6.6 and 37.1 ± 4.5 mmHg, respectively; p BIM-23127; 3 mM) reduced MAP (-19.9 ± 4.4 mmHg; p < 0.05) and RSNA (-17.7 ± 3.8%; p < 0.05) in SHR, but not in NT rats (-2.5 ± 2.8 mmHg; -2.7 ± 5.6%, respectively). These results show that BBS can evoke sympathoexcitatory and pressor responses by activating RVLM BB1 receptors. This pathway might be involved in the maintenance of high levels of arterial blood pressure in SHR. PMID:27313544

  15. Developmental androgen excess programs sympathetic tone and adipose tissue dysfunction and predisposes to a cardiometabolic syndrome in female mice.

    Science.gov (United States)

    Nohara, Kazunari; Waraich, Rizwana S; Liu, Suhuan; Ferron, Mathieu; Waget, Aurélie; Meyers, Matthew S; Karsenty, Gérard; Burcelin, Rémy; Mauvais-Jarvis, Franck

    2013-06-15

    Among women, the polycystic ovarian syndrome (PCOS) is considered a form of metabolic syndrome with reproductive abnormalities. Women with PCOS show increased sympathetic tone, visceral adiposity with enlarged adipocytes, hypoadiponectinemia, insulin resistance, glucose intolerance, increased inactive osteocalcin, and hypertension. Excess fetal exposure to androgens has been hypothesized to play a role in the pathogenesis of PCOS. Previously, we showed that neonatal exposure to the androgen testosterone (NT) programs leptin resistance in adult female mice. Here, we studied the impact of NT on lean and adipose tissues, sympathetic tone in cardiometabolic tissues, and the development of metabolic dysfunction in mice. Neonatally androgenized adult female mice (NTF) displayed masculinization of lean tissues with increased cardiac and skeletal muscle as well as kidney masses. NTF mice showed increased and dysfunctional white adipose tissue with increased sympathetic tone in both visceral and subcutaneous fat as well as increased number of enlarged and insulin-resistant adipocytes that displayed altered expression of developmental genes and hypoadiponectinemia. NTF exhibited dysfunctional brown adipose tissue with increased mass and decreased energy expenditure. They also displayed decreased undercarboxylated and active osteocalcin and were predisposed to obesity during chronic androgen excess. NTF showed increased renal sympathetic tone associated with increased blood pressure, and they developed glucose intolerance and insulin resistance. Thus, developmental exposure to testosterone in female mice programs features of cardiometabolic dysfunction, as can be observed in women with PCOS, including increased sympathetic tone, visceral adiposity, insulin resistance, prediabetes, and hypertension.

  16. Clinical efficacy of efonidipine hydrochloride, a T-type calcium channel inhibitor, on sympathetic activities. Examination using spectral analysis of heart rate/blood pressure variabilities and 123I-Metaiodobenzylguanidine myocardial scintigraphy

    International Nuclear Information System (INIS)

    Dihydropyridine Ca antagonists cause reflex tachycardia related to their hypotensive effects. Efonidipine hydrochloride has inhibitory effects on T-type Ca channels, even as it inhibits reflex tachycardia. In the present study, the influence of efonidipine hydrochloride on heart rate and autonomic nervous function was investigated. Using an electrocardiogram and a tonometric blood pressure measurement, autonomic nervous activity was evaluated using spectral analysis of heart rate/systolic blood pressure variability. Three protocols were used: a single dose of efonidipine hydrochloride was administered orally to healthy subjects with resting heart rate values of 75 beats/min or more (high-heart rate (HR) group) and to healthy subjects with resting heart rate values less than 75 beats/min (low-HR group); efonidipine hydrochloride was newly administered to untreated patients with essential hypertension, and autonomic nervous activity was investigated after a 4-week treatment period; and patients with high heart rate values (≥75 beats/min) who had been treated with a dihydropyridine L-type Ca channel inhibitor for 1 month or more were switched to efonidipine hydrochloride and any changes in autonomic nervous activity were investigated. In all protocols, administration of efonidipine hydrochloride decreased the heart rate in patients with a high heart rate, reduced sympathetic nervous activity, and enhanced parasympathetic nervous activity. In addition, myocardial scintigraphy with 123I-metaiodobenzylguanidine showed significant improvement in the washout rate and heart to mediastinum (H/M) ratio of patients who were switched from other dihydropyridine Ca antagonists to efonidipine hydrochloride. Efonidipine hydrochloride inhibits increases in heart rate and has effects on the autonomic nervous system. It may be useful for treating hypertension and angina pectoris, and may also have a cardiac protective function. (author)

  17. Activation of ATP/UTP-selective receptors increases blood flow and blunts sympathetic vasoconstriction in human skeletal muscle

    DEFF Research Database (Denmark)

    Yegutkin, G.G.; Gonzalez-Alonso, J.; Rosenmeier, Jaya Birgitte

    2008-01-01

    and sympatholytic effects of exogenous ATP in the skeletal muscle vasculature are largely mediated via ATP itself rather than its dephosphorylated metabolites, most likely via binding to endothelial ATP/UTP-selective P2Y(2) receptors. These data are consistent with a role of ATP in skeletal muscle hyperaemia......Sympathetic vasoconstriction is blunted in the vascular beds of contracting skeletal muscle in humans, presumably due to the action of vasoactive metabolites (functional sympatholysis). Recently, we demonstrated that infusion of ATP into the arterial circulation of the resting human leg increases...

  18. Metabolic responses to high-fat or low-fat meals and association with sympathetic nervous system activity in healthy young men.

    Science.gov (United States)

    Nagai, Narumi; Sakane, Naoki; Moritani, Toshio

    2005-10-01

    The present study was designed to investigate the metabolic and sympathetic responses to a high-fat meal in humans. Fourteen young men (age: 23.6 +/- 0.5 y, BMI: 21.3 +/- 0.4 kg/m2) were examined for energy expenditure and fat oxidation measured by indirect calorimetry for 3.5 h after a high-fat (70%, energy from fat) or an isoenergetic low-fat (20% energy from fat) meal served in random order. The sympathetic nervous system (SNS) activity was assessed using power spectral analysis of heart rate variability (HRV). After the high-fat meal, increases in thermoregulatory SNS activity (very low-frequency component of HRV, 0.007-0.035 Hz, 577.4+/-45.9 vs. 432.0+/-49.3 ms2, p<0.05) and fat oxidation (21.0+/-5.3 vs. 13.3+/-4.3 g, p<0.001) were greater than those after the low-fat meal. However, thermic effects of the meal (TEM) were lower after the high-fat meal than after the low-fat meal (27.5+/-11.2 vs. 36.1+/-10.9 kcal, p<0.05). In conclusion, the high-fat meal can stimulate thermoregulatory SNS and lipolysis, but resulted in lower TEM, suggesting that a high proportion of dietary fat intake, even with a normal daily range of calories, may be a potent risk factor for further weight gain.

  19. Cardiac troponin testing in idiopathic inflammatory myopathies and systemic sclerosis-spectrum disorders: biomarkers to distinguish between primary cardiac involvement and low-grade skeletal muscle disease activity.

    Science.gov (United States)

    Hughes, Michael; Lilleker, James B; Herrick, Ariane L; Chinoy, Hector

    2015-05-01

    Primary cardiac involvement, an under-recognised manifestation of the idiopathic inflammatory myopathies (IIM) and systemic sclerosis (SSc)-spectrum disorders, is associated with significant mortality. Within these two conditions, traditional skeletal muscle enzyme testing may not effectively distinguish between skeletal and cardiac muscle involvement, especially in patients with subclinical cardiac disease. Accurate biomarkers are thus required to screen for cardiac disease, to better inform both therapeutic decision-making and treatment response. The widespread uptake of cardiac troponin testing has revolutionised the management of acute coronary syndromes. While cardiac troponin I (cTnI) appears specific to the myocardium, cardiac troponin T (cTnT) is also expressed by skeletal muscle, including regenerating skeletal muscle tissue. There is increasing interest about the role of cardiac troponins as a putative biomarker of primary cardiac involvement in IIM and SSc-spectrum disorders. Herewith we discuss subclinical cardiac disease in IIM and SSc-spectrum disorders, the respective roles of cTnI and cTnT testing, and the re-expression of cTnT within regenerating skeletal muscle tissue. There remains wide variation in access to cardiac troponin testing nationally and internationally. We propose two pragmatic clinical pathways using cardiac troponins, preferably measuring concomitant cTnT followed by confirmatory (cardiac) cTnI to screen patients for subclinical cardiac disease and/or low-grade skeletal muscle disease activity, and also an agenda for future research.

  20. Nitric oxide and the autonomic regulation of cardiac excitability. The G.L. Brown Prize Lecture.

    Science.gov (United States)

    Paterson, D

    2001-01-01

    Cardiac sympathetic imbalance and arrhythmia; Nitric oxide-cGMP pathway and the cholinergic modulation of cardiac excitability; Nitric oxide-cGMP pathway and the sympathetic modulation of cardiac excitability; Functional significance of nitric oxide in the autonomic regulation of cardiac excitability; Summary; References. Experimental Physiology (2001) 86.1, 1-12. PMID:11429613

  1. Nitric oxide and the autonomic regulation of cardiac excitability. The G.L. Brown Prize Lecture.

    Science.gov (United States)

    Paterson, D

    2001-01-01

    Cardiac sympathetic imbalance and arrhythmia; Nitric oxide-cGMP pathway and the cholinergic modulation of cardiac excitability; Nitric oxide-cGMP pathway and the sympathetic modulation of cardiac excitability; Functional significance of nitric oxide in the autonomic regulation of cardiac excitability; Summary; References. Experimental Physiology (2001) 86.1, 1-12.

  2. [Correlations between the coefficient of variation of RR intervals and sympathetic nerve activity following superior tilting in normotensive subjects and in patients with essential hypertension].

    Science.gov (United States)

    Shimazaki, M; Kikuchi, K; Yamaji, I; Kobayakawa, H; Yamamoto, M; Kudo, C; Wada, A; Mukai, H; Iimura, O

    1991-01-01

    The relationship between changes in sympathetic nerve activity and those in parasympathetic tone with a change in position was investigated in patients with essential hypertension using the coefficient of variation of RR intervals on electrocardiograms (CVRR). Mean arterial pressure (MAP), heart rate (HR), plasma noradrenaline concentration (pNA) and CVRR were measured in a supine position at rest and 20 min after having the head tilted 60 degrees superiorly in 10 normotensives (NT: 51.9 +/- 3.0 yrs) and 7 essential hypertensive patients (EHT: 51.0 +/- 2.8 yrs). After changing the position, CVRR decreased significantly in the NT, but not in the EHT; whereas, significant increases of both HR and pNA without significant changes in MAP were shown in both groups. A significant negative correlation between percentage changes in CVRR (% delta CVRR) and pNA (% delta pNA) were observed in the NT, but not in the EHT. However, there was no relationship of % delta CVRR to % delta MAP or to % delta HR in either group. It was suggested from the changes in CVRR that suppression of the parasympathetic tone, which occurs in the NT group corresponding to sympathetic augmentation to present a decrease in blood pressure with a change in position, may be impaired in the EHT group.

  3. Pulse-driven magnetoimpedance sensor detection of cardiac magnetic activity.

    Directory of Open Access Journals (Sweden)

    Shinsuke Nakayama

    Full Text Available This study sought to establish a convenient method for detecting biomagnetic activity in the heart. Electrical activity of the heart simultaneously induces a magnetic field. Detection of this magnetic activity will enable non-contact, noninvasive evaluation to be made. We improved the sensitivity of a pulse-driven magnetoimpedance (PMI sensor, which is used as an electric compass in mobile phones and as a motion sensor of the operation handle in computer games, toward a pico-Tesla (pT level, and measured magnetic fields on the surface of the thoracic wall in humans. The changes in magnetic field detected by this sensor synchronized with the electric activity of the electrocardiogram (ECG. The shape of the magnetic wave was largely altered by shifting the sensor position within 20 mm in parallel and/or perpendicular to the thoracic wall. The magnetic activity was maximal in the 4th intercostals near the center of the sterna. Furthermore, averaging the magnetic activity at 15 mm in the distance between the thoracic wall and the sensor demonstrated magnetic waves mimicking the P wave and QRS complex. The present study shows the application of PMI sensor in detecting cardiac magnetic activity in several healthy subjects, and suggests future applications of this technology in medicine and biology.

  4. Chronic hypoxia inhibits MMP-2 activation and cellular invasion in human cardiac myofibroblasts

    OpenAIRE

    Riches, Kirsten; Morley, Michael E.; Turner, Neil A; O'Regan, David J; Ball, Stephen G; Peers, Chris; Porter, Karen E

    2009-01-01

    Cardiac myofibroblasts are pivotal to adaptive remodelling after myocardial infarction (MI). These normally quiescent cells invade and proliferate as a wound healing response, facilitated by activation of matrix metalloproteinases, particularly MMP-2. Following MI these reparative events occur under chronically hypoxic conditions yet the mechanisms by which hypoxia might modulate MMP-2 activation and cardiac myofibroblast invasion have not been investigated. Human cardiac myofibroblasts cultu...

  5. The Human Sympathetic Nervous System Response to Spaceflight

    Science.gov (United States)

    Ertl, Andrew C.; Diedrich, Andre; Paranjape, Sachin Y.; Biaggioni, Italo; Robertson, Rose Marie; Lane, Lynda D.; Shiavi, Richard; Robertson, David

    2003-01-01

    The sympathetic nervous system is an important part of the autonomic (or automatic) nervous system. When an individual stands up, the sympathetic nervous system speeds the heart and constricts blood vessels to prevent a drop in blood pressure. A significant number of astronauts experience a drop in blood pressure when standing for prolonged periods after they return from spaceflight. Difficulty maintaining blood pressure with standing is also a daily problem for many patients. Indirect evidence available before the Neurolab mission suggested the problem in astronauts while in space might be due partially to reduced sympathetic nervous system activity. The purpose of this experiment was to identify whether sympathetic activity was reduced during spaceflight. Sympathetic nervous system activity can be determined in part by measuring heart rate, nerve activity going to blood vessels, and the release of the hormone norepinephrine into the blood. Norepinephrine is a neurotransmitter discharged from active sympathetic nerve terminals, so its rate of release can serve as a marker of sympathetic nervous system action. In addition to standard cardiovascular measurements (heart rate, blood pressure), we determined sympathetic nerve activity as well as norepinephrine release and clearance on four crewmembers on the Neurolab mission. Contrary to our expectation, the results demonstrated that the astronauts had mildly elevated resting sympathetic nervous system activity in space. Sympathetic nervous system responses to stresses that simulated the cardiovascular effects of standing (lower body negative pressure) were brisk both during and after spaceflight. We concluded that, in the astronauts tested, the activity and response of the sympathetic nervous system to cardiovascular stresses appeared intact and mildly elevated both during and after spaceflight. These changes returned to normal within a few days.

  6. Role of Nuclear Medicine in the cardiac resinchronization therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Simone Cristina Soares, E-mail: simonecordis@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Giorgi, Maria Clementina Pinto; D' Orio, Silvana Angelina; Meneghetti, Jose Claudio [Instituto do Coracao (InCor/FM/USP), Sao Paulo, SP (Brazil)

    2011-10-15

    Cardiac resynchronization therapy (CRT) emerged as one of the most promising approaches in the treatment of cardiac dyssynchrony in heart failure patients' refractory to medical treatment. However, despite very promising clinical and functional results, individual response analyses show that a significant number of patients do not respond to treatment. The role of nuclear medicine and molecular imaging in the selection of CRT candidates by the assessment of cardiac dyssynchrony, myocardial viability, myocardial perfusion and blood flow and sympathetic cardiac activity has been discussed in this review. The potential utilization of this tool to improve the comprehension of detrimental effects of dyssynchrony on cardiac function and the evaluation and monitoring of the response to CRT were also considered. Other molecular targets that characterize glucose and fatty acid metabolism, apoptosis, angiotensin converting enzyme activity and angiogenesis that can be evaluated with this technique were described. (author)

  7. Role of Nuclear Medicine in the cardiac resinchronization therapy

    International Nuclear Information System (INIS)

    Cardiac resynchronization therapy (CRT) emerged as one of the most promising approaches in the treatment of cardiac dyssynchrony in heart failure patients' refractory to medical treatment. However, despite very promising clinical and functional results, individual response analyses show that a significant number of patients do not respond to treatment. The role of nuclear medicine and molecular imaging in the selection of CRT candidates by the assessment of cardiac dyssynchrony, myocardial viability, myocardial perfusion and blood flow and sympathetic cardiac activity has been discussed in this review. The potential utilization of this tool to improve the comprehension of detrimental effects of dyssynchrony on cardiac function and the evaluation and monitoring of the response to CRT were also considered. Other molecular targets that characterize glucose and fatty acid metabolism, apoptosis, angiotensin converting enzyme activity and angiogenesis that can be evaluated with this technique were described. (author)

  8. Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis O balanço autonômico cardíaco nas ratas com miocardite chagásica aguda experimental

    Directory of Open Access Journals (Sweden)

    Diego F. Davila

    1995-04-01

    Full Text Available To clarify the mechanism responsible for the transient sinus tachycardia in rats with acute chagasic myocarditis, we have examined the cardiac sympathetic-parasympathetic balance of 29 rats inoculated with 200,000 parasites (Trypanosoma cruzi. Sixteen infected animals and 8 controls were studied between days 18 and 21 after inoculation (acute stage. The remaining 13 infected animals and 9 controls were studied between days 60 and 70 after inoculation (sub-acute stage. Under anesthesia (urethane 1.25 g/kg, all animals received intravenous atenolol (5 mg/kg and atropine (10 mg/kg. Acute stage: The baseline heart rate of the infected animals was significantly higher than that of the controls (P Com a finalidade de pesquisar o mecanismo responsável pela taquicardia sinusal transitória que ocorre nas ratas com miocardite chagásica aguda, foi estudado o balanço autonômico cardíaco em 16 ratas inoculadas com Trypanosoma cruzi por via intraperitoneal. Oito animais foram estudados aos 18 e 21 dias após-inoculação (Estádio agudo; os oito animais restantes foram estudados entre os dias 60 a 70 após inoculação (Estádio sub-agudo. Todos os animais em estudo bem como os controles receberam atenolol e atropina. No estádio agudo, a frequência cardíaca basal dos animais infectados foi significativamente maior que a dos controles. A resposta cronotrópica negativa pela administração de atenolol foi quatro vezes maior nos animais infectados. No estádio sub-agudo, a frequência cardíaca basal e a resposta cronotrópica ao atenolol e atropina foi similar nos dois grupos do estudo. Os nossos resultados sugerem que no estádio agudo da miocardite chagásica experimental, a atividade simpática encontra-se periodicamente aumentada.

  9. Detection of cardiac activity changes from human speech

    Science.gov (United States)

    Tovarek, Jaromir; Partila, Pavol; Voznak, Miroslav; Mikulec, Martin; Mehic, Miralem

    2015-05-01

    Impact of changes in blood pressure and pulse from human speech is disclosed in this article. The symptoms of increased physical activity are pulse, systolic and diastolic pressure. There are many methods of measuring and indicating these parameters. The measurements must be carried out using devices which are not used in everyday life. In most cases, the measurement of blood pressure and pulse following health problems or other adverse feelings. Nowadays, research teams are trying to design and implement modern methods in ordinary human activities. The main objective of the proposal is to reduce the delay between detecting the adverse pressure and to the mentioned warning signs and feelings. Common and frequent activity of man is speaking, while it is known that the function of the vocal tract can be affected by the change in heart activity. Therefore, it can be a useful parameter for detecting physiological changes. A method for detecting human physiological changes by speech processing and artificial neural network classification is described in this article. The pulse and blood pressure changes was induced by physical exercises in this experiment. The set of measured subjects was formed by ten healthy volunteers of both sexes. None of the subjects was a professional athlete. The process of the experiment was divided into phases before, during and after physical training. Pulse, systolic, diastolic pressure was measured and voice activity was recorded after each of them. The results of this experiment describe a method for detecting increased cardiac activity from human speech using artificial neural network.

  10. Integrin activation and focal complex formation in cardiac hypertrophy

    Science.gov (United States)

    Laser, M.; Willey, C. D.; Jiang, W.; Cooper, G. 4th; Menick, D. R.; Zile, M. R.; Kuppuswamy, D.

    2000-01-01

    Cardiac hypertrophy is characterized by both remodeling of the extracellular matrix (ECM) and hypertrophic growth of the cardiocytes. Here we show increased expression and cytoskeletal association of the ECM proteins fibronectin and vitronectin in pressure-overloaded feline myocardium. These changes are accompanied by cytoskeletal binding and phosphorylation of focal adhesion kinase (FAK) at Tyr-397 and Tyr-925, c-Src at Tyr-416, recruitment of the adapter proteins p130(Cas), Shc, and Nck, and activation of the extracellular-regulated kinases ERK1/2. A synthetic peptide containing the Arg-Gly-Asp (RGD) motif of fibronectin and vitronectin was used to stimulate adult feline cardiomyocytes cultured on laminin or within a type-I collagen matrix. Whereas cardiocytes under both conditions showed RGD-stimulated ERK1/2 activation, only collagen-embedded cells exhibited cytoskeletal assembly of FAK, c-Src, Nck, and Shc. In RGD-stimulated collagen-embedded cells, FAK was phosphorylated only at Tyr-397 and c-Src association occurred without Tyr-416 phosphorylation and p130(Cas) association. Therefore, c-Src activation is not required for its cytoskeletal binding but may be important for additional phosphorylation of FAK. Overall, our study suggests that multiple signaling pathways originate in pressure-overloaded heart following integrin engagement with ECM proteins, including focal complex formation and ERK1/2 activation, and many of these pathways can be activated in cardiomyocytes via RGD-stimulated integrin activation.

  11. Increased sympathetic tone in forearm subcutaneous tissue in primary hypothyroidism

    DEFF Research Database (Denmark)

    Vagn Nielsen, H; Hasselström, K; Feldt-Rasmussen, U;

    1987-01-01

    Sympathetic reflex regulation of subcutaneous blood flow (SBF) in the forearm was studied in eight patients with primary hypothyroidism. Diastolic arterial pressure was greater than or equal to 95 mmHg in five patients. SBF was determined by local clearance of Na99mTcO4. Sympathetic vasoconstrict......Sympathetic reflex regulation of subcutaneous blood flow (SBF) in the forearm was studied in eight patients with primary hypothyroidism. Diastolic arterial pressure was greater than or equal to 95 mmHg in five patients. SBF was determined by local clearance of Na99mTcO4. Sympathetic.......02)). In conclusion sympathetic vasoconstrictor activity in adipose tissue is markedly increased in primary hypothyroidism. Sympathetic tone and arterial pressure are reduced during treatment....

  12. Control of heart rate variability by cardiac parasympathetic nerve activity during voluntary static exercise in humans with tetraplegia.

    Science.gov (United States)

    Takahashi, Makoto; Matsukawa, Kanji; Nakamoto, Tomoko; Tsuchimochi, Hirotsugu; Sakaguchi, Akihiro; Kawaguchi, Kotaro; Onari, Kiyoshi

    2007-11-01

    Heart rate (HR) is controlled solely by via cardiac parasympathetic outflow in tetraplegic individuals, who lack supraspinal control of sympathetic outflows and circulating catecholamines but have intact vagal pathways. A high-frequency component (HF; at 0.15-0.40 Hz) of the power spectrum of HR variability and its relative value against total power (HF/Total) were assessed using a wavelet transform to identify cardiac parasympathetic outflow. The relative contribution of cardiac parasympathetic and sympathetic outflows to controlling HR was estimated by comparing the HF/Total-HR relationship between age-matched tetraplegic and normal men. Six tetraplegic men with complete cervical spinal cord injury performed static arm exercise at 35% of the maximal voluntary contraction until exhaustion. Although resting cardiac output and arterial blood pressure were lower in tetraplegic than normal subjects, HR, HF, and HF/Total were not statistically different between the two groups. When tetraplegic subjects developed the same force during exercise as normal subjects, HF and HF/Total decreased to 67-90% of the preexercise control and gradually recovered 1.5 min after exercise. The amount and time course of the changes in HF/Total during and after exercise coincided well between both groups. In contrast, the increase in HR at the start of exercise was blunted in tetraplegic compared with normal subjects, and the HR recovery following exercise was also delayed. It is likely that, although the withdrawal response of cardiac parasympathetic outflow is preserved in tetraplegic subjects, sympathetic decentralization impairs the rapid acceleration of HR at the onset of exercise and the rapid deceleration following exercise. PMID:17761788

  13. Does Cardiac Rehabilitation After an Acute Cardiac Syndrome Lead to Changes in Physical Activity Habits? Systematic Review

    NARCIS (Netherlands)

    ter Hoeve, Nienke; Huisstede, Bionka M. A.; Stam, Henk J.; van Domburg, Ron T.; Sunamura, Madoka; van den Berg-Emons, Rita J. G.

    2015-01-01

    Background. Optimal physical activity levels have health benefits for patients with acute coronary syndrome (ACS) and are an important goal of cardiac rehabilitation (CR). Purpose. The purpose of this study was to systematically review literature regarding short-term effects (= 6 months after comple

  14. Cardiac repolarization during hypoglycaemia and hypoxaemia in healthy males: Impact of renin-angiotensin system activity

    NARCIS (Netherlands)

    R. Due-Andersen (Rikke); T. Høi-Hansen (Thomas); N.V. Olsen; C.E. Larroude; J.K. Kanters; F. Boomsma (Frans); U. Pedersen-Bjergaard (Ullrik); B. Thorsteinsson (Birger)

    2008-01-01

    textabstractAims: Activity in the renin-angiotensin system (RAS) may influence the susceptibility to cardiac arrhythmia. To study the effect of basal RAS activity on cardiac repolarization during myocardial stress induced by hypoglycaemia or hypoxaemia in healthy humans. Methods and results: Ten sub

  15. Cardiac repolarization during hypoglycaemia and hypoxaemia in healthy males: impact of renin-angiotensin system activity

    DEFF Research Database (Denmark)

    Due-Andersen, Rikke; Høi-Hansen, Thomas; Olsen, Niels Vidiendal;

    2008-01-01

    AIMS: Activity in the renin-angiotensin system (RAS) may influence the susceptibility to cardiac arrhythmia. To study the effect of basal RAS activity on cardiac repolarization during myocardial stress induced by hypoglycaemia or hypoxaemia in healthy humans. METHODS AND RESULTS: Ten subjects...

  16. BLOCKADE OF ROSTRAL VENTROLATERAL MEDULLA (RVLM BOMBESIN RECEPTOR TYPE 1 DECREASES BLOOD PRESSURE AND SYMPATHETIC ACTIVITY IN ANESTHETIZED SPONTANEOUSLY HYPERTENSIVE RATS

    Directory of Open Access Journals (Sweden)

    Izabella Silva De Jesus Pinto

    2016-06-01

    Full Text Available IIntrathecal injection of bombesin (BBS promoted hypertensive and sympathoexcitatory effects in normotensive (NT rats. However, the involvement of rostral ventrolateral medulla (RVLM in these responses is still unclear. In the present study, we investigated: (1 the effects of BBS injected bilaterally into RVLM on cardiorespiratory and sympathetic activity in NT and spontaneously hypertensive rats (SHR; (2 the contribution of RVLM bombesin type 1 receptors (BB1 to the maintenance of hypertension in SHR. Urethane-anesthetized rats (1.2 g · kg−1, i.v. were instrumented to record mean arterial pressure (MAP, diaphragm (DIA motor and renal sympathetic nerve activity (RSNA. In NT rats and SHR, BBS (0.3 mM nanoinjected into RVLM increased MAP (33.9 ± 6.6 mmHg and 37.1 ± 4.5 mmHg, respectively; p < 0.05 and RSNA (97.8 ± 12.9 % and 84.5 ± 18.1 %, respectively; p < 0.05. In SHR, BBS also increased DIA burst amplitude (115.3 ± 22.7 %; p < 0.05. BB1 receptors antagonist (BIM-23127; 3 mM reduced MAP (-19.9 ± 4.4 mmHg; p < 0.05 and RSNA (-17.7 ± 3.8 %; p < 0.05 in SHR, but not in NT rats (-2.5 ± 2.8 mmHg; -2.7 ± 5.6 %, respectively. These results show that BBS can evoke sympathoexcitatory and pressor responses by activating RVLM BB1 receptors. This pathway might be involved in the maintenance of high levels of arterial blood pressure in SHR.

  17. ANGPTL2 activity in cardiac pathologies accelerates heart failure by perturbing cardiac function and energy metabolism

    Science.gov (United States)

    Tian, Zhe; Miyata, Keishi; Kadomatsu, Tsuyoshi; Horiguchi, Haruki; Fukushima, Hiroyuki; Tohyama, Shugo; Ujihara, Yoshihiro; Okumura, Takahiro; Yamaguchi, Satoshi; Zhao, Jiabin; Endo, Motoyoshi; Morinaga, Jun; Sato, Michio; Sugizaki, Taichi; Zhu, Shunshun; Terada, Kazutoyo; Sakaguchi, Hisashi; Komohara, Yoshihiro; Takeya, Motohiro; Takeda, Naoki; Araki, Kimi; Manabe, Ichiro; Fukuda, Keiichi; Otsu, Kinya; Wada, Jun; Murohara, Toyoaki; Mohri, Satoshi; Yamashita, Jun K.; Sano, Motoaki; Oike, Yuichi

    2016-01-01

    A cardioprotective response that alters ventricular contractility or promotes cardiomyocyte enlargement occurs with increased workload in conditions such as hypertension. When that response is excessive, pathological cardiac remodelling occurs, which can progress to heart failure, a leading cause of death worldwide. Mechanisms underlying this response are not fully understood. Here, we report that expression of angiopoietin-like protein 2 (ANGPTL2) increases in pathologically-remodeled hearts of mice and humans, while decreased cardiac ANGPTL2 expression occurs in physiological cardiac remodelling induced by endurance training in mice. Mice overexpressing ANGPTL2 in heart show cardiac dysfunction caused by both inactivation of AKT and sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a signalling and decreased myocardial energy metabolism. Conversely, Angptl2 knockout mice exhibit increased left ventricular contractility and upregulated AKT-SERCA2a signalling and energy metabolism. Finally, ANGPTL2-knockdown in mice subjected to pressure overload ameliorates cardiac dysfunction. Overall, these studies suggest that therapeutic ANGPTL2 suppression could antagonize development of heart failure. PMID:27677409

  18. Sympathetic nerve activity in normal and cystic follicles from isolated bovine ovary: local effect of beta-adrenergic stimulation on steroid secretion

    Directory of Open Access Journals (Sweden)

    Ortega Hugo H

    2011-05-01

    Full Text Available Abstract Cystic ovarian disease (COD is an important cause of abnormal estrous behavior and infertility in dairy cows. COD is mainly observed in high-yielding dairy cows during the first months post-partum, a period of high stress. We have previously reported that, in lower mammals, stress induces a cystic condition similar to the polycystic ovary syndrome in humans and that stress is a definitive component in the human pathology. To know if COD in cows is also associated with high sympathetic activity, we studied isolated small antral (5mm, preovulatory (10mm and cystic follicles (25mm. Cystic follicles which present an area 600 fold greater compared with preovulatory follicles has only 10 times less concentration of NE as compared with small antral and preovulatory follicles but they had 10 times more NE in follicular fluid, suggesting a high efflux of neurotransmitter from the cyst wall. This suggestion was reinforced by the high basal release of recently taken-up 3H-NE found in cystic follicles. While lower levels of beta-adrenergic receptor were found in cystic follicles, there was a heightened response to the beta-adrenergic agonist isoproterenol and to hCG, as measured by testosterone secretion. There was however an unexpected capacity of the ovary in vitro to produce cortisol and to secrete it in response to hCG but not to isoproterenol. These data suggest that, during COD, the bovine ovary is under high sympathetic nerve activity that in addition to an increased response to hCG in cortisol secretion could participate in COD development.

  19. Mechanism of relation among heart meridian, referred cardiac pain and heart

    Institute of Scientific and Technical Information of China (English)

    RONG; Peijing(荣培晶); ZHU; Bing(朱兵)

    2002-01-01

    It has been demonstrated that an important clinical phenomenon often associated with visceral diseases is the referred pain to somatic structures, especially to the body areaof homo-segmental innervation. It is interesting that the somatic foci of cardiac referred pain wereoften and mainly distributed along the heart meridian (HM), whereas the acupoints of HM havebeen applied to treat cardiac disease since ancient times. The purpose of this study was to inves-tigate the neural relationship between the cardiac referred pain and the heart meridian.Fluorescent triple-labeling was injected into the pericardium, some acupoints of HM and lung me-ridian (LM, for control). The responses of the left cardiac sympathetic nerve and of the EMG in left HM and LM were electrophysiologically studied, when the electrical stimuli were applied to the acupoints of left HM and to the left cardiac sympathetic nerve. More double-labeled neurons in HM-heart, not in LM-heart, were observed in the ipsilateral dorsal root ganglia of the spinal segments C8-T3. Electric stimulation of the acupoints of left HM was able to elicit more responses of left cardiac sympathetic nerve than that of the LM-acupoints. Electric stimulation of the left cardiac sympathetic nerve resulted in stronger activities of EMG-response in the acupoints of left HM than in LM-acupoints. We conclude that double-labeling study has provided direct evidence for the existence of dichotomizing afferent fibers that supply both the pericardium and HM. Electrophysiological results show that HM is more closely related functionally to heart. These findings provide a possible morphological and physiological explanation for the referred cardiac pain and HM-heart interrelation.

  20. Adrenal GRK2 upregulation mediates sympathetic overdrive in heart failure.

    Science.gov (United States)

    Lymperopoulos, Anastasios; Rengo, Giuseppe; Funakoshi, Hajime; Eckhart, Andrea D; Koch, Walter J

    2007-03-01

    Cardiac overstimulation by the sympathetic nervous system (SNS) is a salient characteristic of heart failure, reflected by elevated circulating levels of catecholamines. The success of beta-adrenergic receptor (betaAR) antagonists in heart failure argues for SNS hyperactivity being pathogenic; however, sympatholytic agents targeting alpha2AR-mediated catecholamine inhibition have been unsuccessful. By investigating adrenal adrenergic receptor signaling in heart failure models, we found molecular mechanisms to explain the failure of sympatholytic agents and discovered a new strategy to lower SNS activity. During heart failure, there is substantial alpha2AR dysregulation in the adrenal gland, triggered by increased expression and activity of G protein-coupled receptor kinase 2 (GRK2). Adrenal gland-specific GRK2 inhibition reversed alpha2AR dysregulation in heart failure, resulting in lowered plasma catecholamine levels, improved cardiac betaAR signaling and function, and increased sympatholytic efficacy of a alpha2AR agonist. This is the first demonstration, to our knowledge, of a molecular mechanism for SNS hyperactivity in heart failure, and our study identifies adrenal GRK2 activity as a new sympatholytic target.

  1. A case of delayed cardiac perforation of active ventricular lead

    Directory of Open Access Journals (Sweden)

    Hangyuan Guo

    2011-12-01

    Full Text Available A 65-year-old man was admitted as for one month of repetitive dizziness and one episode of syncope. Electrocardiogram showed sinus bradycardia and his Holter monitoring also showed sinus bradycardia with sinus arrest, sino-atrial block and a longest pause of 4.3 s. Then sick sinus syndrome and Adam-Stokes syndrome were diagnosed. Then a dual chamber pacemaker (Medtronic SDR303 was implanted and the parameters were normal by detection. The patient was discharged 1 week later with suture removed. Then 1.5 month late the patient was presented to hospital once again for sudden onset of chest pain with exacerbation after taking deep breath. Pacemaker programming showed both pacing and sensing abnormality with threshold of?5.0V and resistance of 1200?. Lead perforation was revealed by chest X-ray and confirmed by echocardiogram. Considering the fact that there was high risk to remove ventricular lead, spiral tip of previous ventricular lead was withdrew followed by implantation of a new ventricular active lead to the septum. Previous ventricular lead was maintained. As we know that the complications of lead perforation in the clinic was rare. Here we discuss the clinical management and the possible reasons for cardiac perforation of active ventricular lead.

  2. Complement activation and its prognostic role in post-cardiac arrest patients

    DEFF Research Database (Denmark)

    Jenei, Z M; Zima, E; Csuka, D;

    2014-01-01

    of therapeutic hypothermia predicted 30-day mortality regardless of age, sex and the APACHE II score. Complement activation occurs in post-cardiac arrest patients, and its extent correlates with 30-day survival. The C3a/C3 ratio might prove useful for estimating the prognosis of comatose post-cardiac arrest...

  3. The influence of motor activity on the development of cardiac arrhythmias during experimental emotional stress

    Science.gov (United States)

    Ulyaninskiy, L. S.; Urmancheyeva, T. G.; Stepanyan, Y. P.; Fufacheva, A. A.; Gritsak, A. V.; Kuznetsova, B. A.; Kvitka, A. A.

    1982-01-01

    Experimental emotional stress which can produce various disorders of cardiac rhythm: sinus tachycardia, atrial fibrillation, ventricular, extrasystoles and paroxysmal ventricular tachysystoles was studied. In these conditions the adrenalin content in the blood and myocardium is increased 3 to 4 times. It is found that moderate motor activity leads to a relative decrease of adrenalin in the myocardium and arrest of cardiac arrhythmias.

  4. Comparative Analysis of Telomerase Activity in CD117+CD34+ Cardiac Telocytes with Bone Mesenchymal Stem Cells, Cardiac Fibroblasts and Cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    Yuan-Yuan Li; Shan-Shan Lu; Ting Xu; Hong-Qi Zhang; Hua Li

    2015-01-01

    Background:This study characterized the cardiac telocyte (TC) population both in vivo and in vitro,and investigated its telomerase activity related to mitosis.Methods:Using transmission electron microscopy and a phase contrast microscope,the typical morphological features of cardiac TCs were observed;by targeting the cell surface proteins CD 1 17 and CD34,CD 117+CD34+ cardiac TCs were sorted via flow cytometry and validated by immunofluorescence based on the primary cell culture.Then the optimized basal nutrient medium for selected population was examined with the cell counting kit 8.Under this conditioned medium,the process of cell division was captured,and the telomerase activity ofCD 117+CD34+ cardiac TCs was detected in comparison with bone mesenchymal stem cells (BMSCs),cardiac fibroblasts (CFBs),cardiomyocytes (CMs).Results:Cardiac TCs projected characteristic telopodes with thin segments (podomers) in alternation with dilation (podoms).In addition,64% of the primary cultured cardiac TCs were composed of CD 117+CD34+ cardiac TCs;which was verified by immunofluorescence.In a live cell imaging system,CD 117+CD34+ cardiac TCs were observed to enter into cell division in a short time,followed by an significant invagination forming across the middle of the cell body.Using a real-time quantitative telomeric-repeat amplification assay,the telomerase concentration in CD117+CD34+ cardiac TCs was obviously lower than in BMSCs and CFBs,and significantly higher than in CMs.Conclusions:Cardiac TCs represent a unique cell population and CD117+CD34+ cardiac TCs have relative low telomerase activity that differs from BMSCs,CFBs and CMs and thus they might play an important role in maintaining cardiac homeostasis.

  5. Comparative Analysis of Telomerase Activity in CD117+CD34+ Cardiac Telocytes with Bone Mesenchymal Stem Cells, Cardiac Fibroblasts and Cardiomyocytes

    Science.gov (United States)

    Li, Yuan-Yuan; Lu, Shan-Shan; Xu, Ting; Zhang, Hong-Qi; Li, Hua

    2015-01-01

    Background: This study characterized the cardiac telocyte (TC) population both in vivo and in vitro, and investigated its telomerase activity related to mitosis. Methods: Using transmission electron microscopy and a phase contrast microscope, the typical morphological features of cardiac TCs were observed; by targeting the cell surface proteins CD117 and CD34, CD117+CD34+ cardiac TCs were sorted via flow cytometry and validated by immunofluorescence based on the primary cell culture. Then the optimized basal nutrient medium for selected population was examined with the cell counting kit 8. Under this conditioned medium, the process of cell division was captured, and the telomerase activity of CD117+CD34+ cardiac TCs was detected in comparison with bone mesenchymal stem cells (BMSCs), cardiac fibroblasts (CFBs), cardiomyocytes (CMs). Results: Cardiac TCs projected characteristic telopodes with thin segments (podomers) in alternation with dilation (podoms). In addition, 64% of the primary cultured cardiac TCs were composed of CD117+CD34+ cardiac TCs; which was verified by immunofluorescence. In a live cell imaging system, CD117+CD34+ cardiac TCs were observed to enter into cell division in a short time, followed by an significant invagination forming across the middle of the cell body. Using a real-time quantitative telomeric-repeat amplification assay, the telomerase concentration in CD117+CD34+ cardiac TCs was obviously lower than in BMSCs and CFBs, and significantly higher than in CMs. Conclusions: Cardiac TCs represent a unique cell population and CD117+CD34+ cardiac TCs have relative low telomerase activity that differs from BMSCs, CFBs and CMs and thus they might play an important role in maintaining cardiac homeostasis. PMID:26168836

  6. Adrenergic innervation of the developing chick heart: neural crest ablations to produce sympathetically aneural hearts

    International Nuclear Information System (INIS)

    Ablation of various regions of premigratory trunk neural crest which gives rise to the sympathetic trunks was used to remove sympathetic cardiac innervation. Neuronal uptake of [3H]-norepinephrine was used as an index of neuronal development in the chick atrium. Following ablation of neural crest over somites 10-15 or 15-20, uptake was significantly decreased in the atrium at 16 and 17 days of development. Ablation of neural crest over somites 5-10 and 20-25 caused no decrease in [3H]-norepinephrine uptake. Removal of neural crest over somites 5-25 or 10-20 caused approximately equal depletions of [3H]-norepinephrine uptake in the atrium. Cardiac norepinephrine concentration was significantly depressed following ablation of neural crest over somites 5-25 but not over somites 10-20. Light-microscopic and histofluorescent preparations confirmed the absence of sympathetic trunks in the region of the normal origin of the sympathetic cardiac nerves following neural crest ablation over somites 10-20. The neural tube and dorsal root ganglia were damaged in the area of the neural-crest ablation; however, all of these structures were normal cranial and caudal to the lesioned area. Development of most of the embryos as well as the morphology of all of the hearts was normal following the lesion. These results indicate that it is possible to produce sympathetically aneural hearts by neural-crest ablation; however, sympathetic cardiac nerves account for an insignificant amount of cardiac norepinephrine

  7. Catecholamine-induced excitation of nociceptors in sympathetically maintained pain.

    Science.gov (United States)

    Jørum, Ellen; Ørstavik, Kristin; Schmidt, Roland; Namer, Barbara; Carr, Richard W; Kvarstein, Gunnvald; Hilliges, Marita; Handwerker, Hermann; Torebjörk, Erik; Schmelz, Martin

    2007-02-01

    Sympathetically maintained pain could either be mediated by ephaptic interactions between sympathetic efferent and afferent nociceptive fibers or by catecholamine-induced activation of nociceptive nerve endings. We report here single fiber recordings from C nociceptors in a patient with sympathetically maintained pain, in whom sympathetic blockade had repeatedly eliminated the ongoing pain in both legs. We classified eight C-fibers as mechano-responsive and six as mechano-insensitive nociceptors according to their mechanical responsiveness and activity-dependent slowing of conduction velocity (latency increase of 0.5+/-1.1 vs. 7.1+/-2.0 ms for 20 pulses at 0.125 Hz). Two C-fibers were activated with a delay of several seconds following strong endogenous sympathetic bursts; they were also excited for about 3 min following the injection of norepinephrine (10 microl, 0.05%) into their innervation territory. In these two fibers, a prolonged activation by injection of low pH solution (phosphate buffer, pH 6.0, 10 microl) and sensitization of their heat response following prostaglandin E2 injection were recorded, evidencing their afferent nature. Moreover, their activity-dependent slowing was typical for mechano-insensitive nociceptors. We conclude that sensitized mechano-insensitive nociceptors can be activated by endogenously released catecholamines and thereby may contribute to sympathetically maintained pain. No evidence for ephaptic interaction between sympathetic efferent and nociceptive afferent fibers was found. PMID:16997471

  8. Non-dipping blood pressure variations in adult Kazakhs are derived from decreased daytime physical activity and increased nighttime sympathetic activity.

    Science.gov (United States)

    Kawamura, Hiroshi; Ozawa, Yukio; Izumi, Yoichi; Kasamaki, Yuji; Nakayama, Tomohiro; Mitsubayashi, Hiromi; Ohta, Masakatsu; Ichimaru, Yuhei

    2016-01-01

    Many of the elderly Kazakhs have been found to exhibit non-dipping blood pressure variations (BPV). Such variations are seen in both normotensive and hypertensive Kazakhs. The purpose of this study was (1) to determine whether middle-aged Kazakhs also include large numbers of non-dippers, (2) to compare the characteristics of non-dipping and dipping, and (3) to clarify the mechanisms responsible for non-dipping type BPV by examining the autonomic nervous activity and physical activity. We performed ambulatory blood pressure (BP) monitoring. The subjects were divided into two groups (dipping and non-dipping type). We monitored the subjects' physical activity with accelerometry and assessed their autonomic nerve activity by performing a frequency domain analysis of their heart rate variability (HRV). The power spectral density (PSD) of the HRV was calculated using fast Fourier transformation. We analyzed the systolic blood pressure (SBP) variations with the maximum entropy method (MEM). The dippers and non-dippers accounted for 48% and 52% of the subjects, respectively. MEM analysis revealed that the SBP variations of the non-dippers exhibited a 24 hour periodicity with a very weak PSD as well as an ultradian periodicity. The non-dippers exhibited higher low-frequency/high-frequency (LF/HF) ratio and lower HF/(LF + HF) ratios than the dippers, particularly during the nighttime. In addition, the non-dippers performed less physical activity than the dippers. These differences in cardiac autonomic function and physical activity might contribute to the generation of a weak circadian rhythm in SBP, and thus, ultimately lead to the non-dipping SBP variations observed in non-dipper Kazakhs.

  9. Are hospitals also for relatives? A survey of hospitals' activities regarding relatives of cardiac patients

    DEFF Research Database (Denmark)

    Nissen, Nina Konstantin; Madsen, Mette; Kjøller, Mette;

    2008-01-01

    AIM: Patients and their close relatives both feel the burden of cardiovascular disease. Relatives of heart patients experience lower quality of life and increased mortality than the general population and relatives of patients with other diseases. Nevertheless, knowledge on health services aimed...... at relatives of patients with cardiac diseases is sparse. This study aimed to survey the prevalence of health services for relatives of cardiac patients in Denmark. METHODS: We surveyed activities offered by Danish hospitals to the relatives of cardiac patients. Data were obtained from an Internet-based survey...... and 50 of 55 invited hospital departments participated. RESULTS: Almost all departments offer activities to relatives of cardiac patients, but only one-quarter have activities specifically aimed at supporting relatives. Large departments offer activities for relatives more often than smaller departments...

  10. Lower limb pain in sympathetic-sensory coupling

    Institute of Scientific and Technical Information of China (English)

    Hongjun Yang; Kairun Peng; Sanjue Hu; Li Xuan

    2011-01-01

    Previous studies have shown that sympathetic nerves are related to certain types of pain, and this phenomenon is referred to as sympathetic-sensory coupling. Chronic pain resulting from nerve injury can be exacerbated by sympathetic stimulation or relieved by sympathetic inhibition. In the present study, the correlation between pain and sympathetic nerves was analyzed in patients with severe pain in lower limbs, as well as in a chronically compressed dorsal root ganglion (CCD) rat model (model of low back pain and sciatica). Patients with severe pain in the lower limbs underwent chemical lumbar sympathectomy (CLS), and the analgesic effects of CLS were compared with painkillers. Results demonstrated significantly relieved lower limb pain following CLS, and the analgesic effects of CLS were superior to those seen with painkillers. In the CCD rat model, dorsal root ganglion neuronal activity significantly increased as a result of electrical stimulation to the sympathetic nerves. These results suggest that sympathetic nerves are closely associated with pain and sympathetic-sensory coupling is likely in lower limb pain in both patients and rat models of CCD.

  11. Effects of sympathetic activation on QT hysteresis%交感神经张力对犬QT滞后现象的影响

    Institute of Scientific and Technical Information of China (English)

    包明威; 张逸杰; 钟慧; 李彦; 谭团团

    2014-01-01

    Objective To investigate the role of sympathetic activation in the mechanism of QT hysteresis.Methods Dynamic heart rate fluctuation was produced by right atrium(RA)pacing,and sympathetic activity was regulated by isopropylarterenol(ISO) or propranolol intravenous injection.Five protocols were used for investigating the effects of sympathetic activity on QT interval hysteresis,including A:right atrium increase-decrease frequency pacing,B:ISO intravenous injection,C:propranolol intravenous injection + protocol A,D:propranolol intravenous injection + protocol B,E:destroy sinoatrial node + low dose ISO intravenous injection + protocol A.The surface electrocardiogram was recorded,RR and QT interval were determined.Plotted the QTRR and calculated the QT hysteresis index.The QT hysteresis index was compared among different protocols,and the effects of autonomic nerve on QT hysteresis index were evaluated.Results The QTe and QTp hysteresis index in protocol A were significantly lower than that in protocol B [QTe:(0.56±4.56) ms vs.(17.96± 8.22) ms,P< 0.05 ; QTp:(0.50 ± 3.14) ms vs.(11.33 ± 13.47) ms,P< 0.05].There was no significant difference in QTe hysteresis index between protocol A and C [(0.56±4.56)ms vs.(2.34±2.84)ms,P>0.05],but the QTp hysteresis index in protocol A was significantly higher than that in protocol C [QTp:(0.50± 3.14).ms vs.(-5.45±2.13)ms,P<0.05].There was no significant difference between protocol B and C [QTe:(17.12± 10.47) ms vs.(15.77± 14.89) ms,P>0.05 ; QTp:(11.33 ± 13.47) ms vs.(17.12± 10.47) ms,P>0.05].The QTe and QTp hysteresis indexes in protocol C were significantly lower than that in protocol D [QTe:(2.34± 2.84)ms vs.(15.77±14.89) ms,P<0.05 ;QTp:(-5.45±2.13)ms vs.(17.12±10.47) ms,P<0.05].The QTe hysteresis index in protocol A was significantly lower than that in protocol E [QTe:(0.56±4.56) ms vs.(8.42± 7.86) ms,P<0.05],but not QTp [(0.50±3.14)ms vs.(0.62±7.46)ms,P>0.05].The QTe and QTp hysteresis

  12. Vitamin D Levels Are Associated with Cardiac Autonomic Activity in Healthy Humans

    OpenAIRE

    Linda Ellis; Turin, Tanvir C.; Sola, Darlene Y.; Hemmelgarn, Brenda R.; Exner, Derek V.; Mann, Michelle C.; Ahmed, Sofia B.

    2013-01-01

    Vitamin D deficiency (≤50nmol/L 25-hydroxy vitamin D) is a cardiovascular (CV) risk factor that affects approximately one billion people worldwide, particularly those affected by chronic kidney disease (CKD). Individuals with CKD demonstrate abnormal cardiac autonomic nervous system activity, which has been linked to the significant rates of CV-related mortality in this population. Whether vitamin D deficiency has a direct association with regulation of cardiac autonomic activity has never be...

  13. Cardiac modeling using active appearance models and morphological operators

    Science.gov (United States)

    Pfeifer, Bernhard; Hanser, Friedrich; Seger, Michael; Hintermueller, Christoph; Modre-Osprian, Robert; Fischer, Gerald; Muehlthaler, Hannes; Trieb, Thomas; Tilg, Bernhard

    2005-04-01

    We present an approach for fast reconstructing of cardiac myocardium and blood masses of a patient's heart from morphological image data, acquired either MRI or CT, in order to estimate numerically the spread of electrical excitation in the patient's atria and ventricles. The approach can be divided into two main steps. During the first step the ventricular and atrial blood masses are extracted employing Active Appearance Models (AAM). The left and right ventricular blood masses are segmented automatically after providing the positions of the apex cordis and the base of the heart. Because of the complex geometry of the atria the segmentation process of the atrial blood masses requires more information as the ventricular blood mass segmentation process of the ventricles. We divided, for this reason, the left and right atrium into three divisions of appearance. This proved sufficient for the 2D AAM model to extract the target blood masses. The base of the heart, the left upper and left lower pulmonary vein from its first up to its last appearance in the image stack, and the right upper and lower pulmonary vein have to be marked. After separating the volume data into these divisions the 2D AAM search procedure extracts the blood masses which are the main input for the second and last step in the myocardium extraction pipeline. This step uses morphologically-based operations in order to extract the ventricular and atrial myocardium either directly by detecting the myocardium in the volume block or by reconstructing the myocardium using mean model information, in case the algorithm fails to detect the myocardium.

  14. Aircraft noise effects on sleep: a systematic comparison of EEG awakenings and automatically detected cardiac activations

    International Nuclear Information System (INIS)

    Polysomnography is the gold standard for investigating noise effects on sleep, but data collection and analysis are sumptuous and expensive. We recently developed an algorithm for the automatic identification of cardiac activations associated with cortical arousals, which uses heart rate information derived from a single electrocardiogram (ECG) channel. We hypothesized that cardiac activations can be used as estimates for EEG awakenings. Polysomnographic EEG awakenings and automatically detected cardiac activations were systematically compared using laboratory data of 112 subjects (47 male, mean ± SD age 37.9 ± 13 years), 985 nights and 23 855 aircraft noise events (ANEs). The probability of automatically detected cardiac activations increased monotonically with increasing maximum sound pressure levels of ANEs, exceeding the probability of EEG awakenings by up to 18.1%. If spontaneous reactions were taken into account, exposure–response curves were practically identical for EEG awakenings and cardiac activations. Automatically detected cardiac activations may be used as estimates for EEG awakenings. More investigations are needed to further validate the ECG algorithm in the field and to investigate inter-individual differences in its ability to predict EEG awakenings. This inexpensive, objective and non-invasive method facilitates large-scale field studies on the effects of traffic noise on sleep

  15. Detection of telornerase activity and cytology in diagnosis of cardiac cancer

    Institute of Scientific and Technical Information of China (English)

    Qiang Wang; Qing Ming Wu; Sheng Bao Li

    2000-01-01

    AIM To investigate the diagnostic significance of cytology and telomerase activity in the exfoliated cells ofcardia obtained from endoscopic brushing in the cardiac cancer.METHODS The techniques of the qualitative TRAP-silver staining and quantitative TRAP-PCR-ELISAwere employed to detect telomerase activity in the exfoliated cells of cardia obtained from endoscopicbrushing in 72 cases with cardial lesions, cytological diagnosis was made at the same time.RESULTS Telomerase activity with cardiac cancer group (1.521 ± 0. 192) was significantly higher than thatwith cardialitis group (0.065± 0.014). Positive rate of telomerase activity detected in cardiac cancer group(88.89%) was significantly higher than that with cardialitis group (11.11%), the former was significantlyhiger than cytological examination (77.78%). The diagnostic rate of cardiac cancer reached 93.33% iftelomerase activity and cytology were examined at the same time.CONCLUSION Cytology and telomerase activity in the exfoliated cardiac cells may be an effective andsensitive methods in the diagnosis of cardiac cancer. This research can be a basis for the mass screening ofcardiac cancer.

  16. Iodine-123 metaiodobenzylguanidine imaging of the heart in idiopathic congestive cardiomyopathy and cardiac transplants

    Energy Technology Data Exchange (ETDEWEB)

    Glowniak, J.V.; Turner, F.E.; Gray, L.L.; Palac, R.T.; Lagunas-Solar, M.C.; Woodward, W.R.

    1989-07-01

    Iodine-123 metaiodobenzylguanidine ((/sup 123/I)MIBG) is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. In this study, cardiac imaging with (/sup 123/I)MIBG was performed in patients with idiopathic congestive cardiomyopathy and compared to normal controls. Initial uptake, half-time of tracer within the heart, and heart to lung ratios were all significantly reduced in patients compared to normals. Uptake in lungs, liver, salivary glands, and spleen was similar in controls and patients with cardiomyopathy indicating that decreased MIBG uptake was not a generalized abnormality in these patients. Iodine-123 MIBG imaging was also performed in cardiac transplant patients to determine cardiac nonneuronal uptake. Uptake in transplants was less than 10% of normals in the first 2 hr and nearly undetectable after 16 hr. The decreased uptake of MIBG suggests cardiac sympathetic nerve dysfunction while the rapid washout of MIBG from the heart suggests increased cardiac sympathetic nerve activity in idiopathic congestive cardiomyopathy.

  17. Acidosis-induced p38 MAPK activation and its implication in regulation of cardiac contractility

    Institute of Scientific and Technical Information of China (English)

    Ming ZHENG; Rong HOU; Rui-ping XIAO

    2004-01-01

    AIM: To determine the possible role of pH in mediating activation of p38 mitogen-activated protein kinase (MAPK) and the consequent function of activated p38 MAPK in regulating cardiac contractility. METHODS: Adult rat cardiomyocytes were isolated and cultured. Low pH media was used to induce intracellular acidosis and contraction of single cardiomyocyte was measured. RESULTS: Phosphorylation of p38 MAPK was increased during ischemia, and pHi was decreased. Intracellular acidosis activated p38 MAPK to a similar level as ischemia. Inhibition of p38 MAPK activation by SB203580, a specific inhibitor of p38 MAPK, reversed acidosis-mediated reduction of myocyte contractility. CONCLUSION: In adult rat cardiomyocytes, intracellular acidification activated p38 MAPK and decreased cardiac contractility. Pretreatment of cardiomyocytes with SB203580 completely blocked p38 MAPK activation and partially reversed acidosis-mediated decline of cardiac contractility.

  18. A new method based on fractal variance function for analysis and quantification of sympathetic and vagal activity in variability of R-R time series in ECG signals

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Elio [Department of Pharmacology and Human Physiology and Tires, Center for Innovative Technologies for Signal Detection and Processing, University of Bari, Bari (Italy); School of Advanced International Studies on Nuclear, Theoretical and Nonlinear Methodologies-Bari (Italy)], E-mail: fisio2@fisiol.uniba.it; Federici, Antonio [Department of Pharmacology and Human Physiology and Tires, Center for Innovative Technologies for Signal Detection and Processing, University of Bari, Bari (Italy); Zbilut, Joseph P. [Department of Molecular Biophysics and Physiology, Rush University Medical Center, 1653W Congress, Chicago, IL 60612 (United States)

    2009-08-15

    It is known that R-R time series calculated from a recorded ECG, are strongly correlated to sympathetic and vagal regulation of the sinus pacemaker activity. In human physiology it is a crucial question to estimate such components with accuracy. Fourier analysis dominates still to day the data analysis efforts of such data ignoring that FFT is valid under some crucial restrictions that results largely violated in R-R time series data as linearity and stationarity. In order to go over such approach, we introduce a new method, called CZF. It is based on variogram analysis. It is aimed from a profound link with Recurrence Quantification Analysis that is a basic tool for investigation of non linear and non stationary time series. Therefore, a relevant feature of the method is that it finally may be applied also in cases of non linear and non stationary time series analysis. In addition, the method enables also to analyze the fractal variance function, the Generalized Fractal Dimension and, finally, the relative probability density function of the data. The CZF gives very satisfactory results. In the present paper it has been applied to direct experimental cases of normal subjects, patients with hypertension before and after therapy and in children under some different conditions of experimentation.

  19. Insulin increases sympathetic nerve activity in part by suppression of tonic inhibitory neuropeptide Y inputs into the paraventricular nucleus in female rats.

    Science.gov (United States)

    Cassaglia, Priscila A; Shi, Zhigang; Brooks, Virginia L

    2016-07-01

    Following binding to receptors in the arcuate nucleus (ArcN), insulin increases sympathetic nerve activity (SNA) and baroreflex control of SNA via a pathway that includes the paraventricular nucleus of the hypothalamus (PVN). Previous studies in males indicate that the sympathoexcitatory response is mediated by α-melanocyte stimulating hormone (α-MSH), which binds to PVN melanocortin type 3/4 receptors (MC3/4R). The present study was conducted in α-chloralose-anesthetized female rats to test the hypothesis that suppression of inhibitory neuropeptide Y (NPY) inputs to the PVN is also involved. In support of this, blockade of PVN NPY Y1 receptors with BIBO 3304 (NPY1x), ArcN insulin nanoinjections, and PVN NPY1x followed by ArcN insulin each increased lumbar SNA (LSNA) and its baroreflex regulation similarly. Moreover, prior PVN injections of NPY blocked the sympathoexcitatory effects of ArcN insulin. Finally, PVN nanoinjections of the MC3/4R inhibitor SHU9119 prevented both the acute (15 min) and longer, more slowly developing (60 min), increases in LSNA in response to ArcN insulin. In conclusion, in females, ArcN insulin increases LSNA, in part, by suppressing tonic PVN NPY inhibition, which unmasks excitatory α-MSH drive of LSNA. Moreover, the steadily increasing rise in LSNA induced by ArcN insulin is also dependent on PVN MC3/4R. PMID:27122366

  20. 1,25 Dihydroxyvitamin D3 Inhibits TGFβ1-Mediated Primary Human Cardiac Myofibroblast Activation.

    Directory of Open Access Journals (Sweden)

    Anna Meredith

    Full Text Available Epidemiological and interventional studies have suggested a protective role for vitamin D in cardiovascular disease, and basic research has implicated vitamin D as a potential inhibitor of fibrosis in a number of organ systems; yet little is known regarding direct effects of vitamin D on human cardiac cells. Given the critical role of fibrotic responses in end stage cardiac disease, we examined the effect of active vitamin D treatment on fibrotic responses in primary human adult ventricular cardiac fibroblasts (HCF-av, and investigated the relationship between circulating vitamin D (25(OHD3 and cardiac fibrosis in human myocardial samples.Interstitial cardiac fibrosis in end stage HF was evaluated by image analysis of picrosirius red stained myocardial sections. Serum 25(OHD3 levels were assayed using mass spectrometry. Commercially available HCF-av were treated with transforming growth factor (TGFβ1 to induce activation, in the presence or absence of active vitamin D (1,25(OH2D3. Functional responses of fibroblasts were analyzed by in vitro collagen gel contraction assay. 1,25(OH2D3 treatment significantly inhibited TGFβ1-mediated cell contraction, and confocal imaging demonstrated reduced stress fiber formation in the presence of 1,25(OH2D3. Treatment with 1,25(OH2D3 reduced alpha-smooth muscle actin expression to control levels and inhibited SMAD2 phosphorylation.Our results demonstrate that active vitamin D can prevent TGFβ1-mediated biochemical and functional pro-fibrotic changes in human primary cardiac fibroblasts. An inverse relationship between vitamin D status and cardiac fibrosis in end stage heart failure was observed. Collectively, our data support an inhibitory role for vitamin D in cardiac fibrosis.

  1. Glutamate and GABA in vestibulo-sympathetic pathway neurons

    Directory of Open Access Journals (Sweden)

    Gay R Holstein

    2016-02-01

    Full Text Available The vestibulo-sympathetic reflex actively modulates blood pressure during changes in posture. This reflex allows humans to stand up and quadrupeds to rear or climb without a precipitous decline in cerebral perfusion. The vestibulo-sympathetic reflex pathway conveys signals from the vestibular end organs to the caudal vestibular nuclei. These cells, in turn, project to pre-sympathetic neurons in the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively. The present study assessed glutamate- and GABA-related immunofluorescence associated with central vestibular neurons of the vestibulo-sympathetic reflex pathway in rats. Retrograde FluoroGold tract tracing was used to label vestibular neurons with projections to RVLM or CVLM, and sinusoidal galvanic vestibular stimulation was employed to activate these pathways. Central vestibular neurons of the vestibulo-sympathetic reflex were identified by co-localization of FluoroGold and cFos protein, which accumulates in some vestibular neurons following galvanic stimulation. Triple-label immunofluorescence was used to co-localize glutamate- or GABA- labeling in the identified vestibulo-sympathetic reflex pathway neurons. Most activated projection neurons displayed intense glutamate immunofluorescence, suggestive of glutamatergic neurotransmission. To support this, anterograde tracer was injected into the caudal vestibular nuclei. Vestibular axons and terminals in RVLM and CVLM co-localized the anterograde tracer and vesicular glutamate transporter-2 signals. Other retrogradely-labeled cFos-positive neurons displayed intense GABA immunofluorescence. Vestibulo-sympathetic reflex pathway neurons of both phenotypes were present in the caudal medial and spinal vestibular nuclei, and projected to both RVLM and CVLM. As a group, however, triple-labeled vestibular cells with intense glutamate immunofluorescence were located more rostrally in the vestibular nuclei than the GABAergic neurons. Only the

  2. Dynamic resistance training decreases sympathetic tone in hypertensive ovariectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Shimojo, G.L.; Palma, R.K.; Brito, J.O.; Sanches, I.C. [Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP (Brazil); Irigoyen, M.C. [Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); De Angelis, K. [Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP (Brazil)

    2015-03-27

    The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and resistance-trained hypertensive ovariectomized (RTHO). Resistance exercise training was performed on a vertical ladder (5 days/week, 8 weeks) at 40-60% maximal load. Direct arterial pressure was recorded. Vagal and sympathetic tones were measured by heart rate (HR) responses to methylatropine (3 mg/kg, iv) and propranolol (4 mg/kg, iv). Ovariectomy resulted in additional increases in blood pressure in hypertensive rats and was associated with decreased vagal tone. Resistance exercise trained rats had lower mean arterial pressure than untrained rats (RTHO: 159±2.2 vs SHO: 177±3.4 mmHg), as well as resting bradycardia (RTHO: 332±9.0 vs SHO: 356±5 bpm). Sympathetic tone was also lower in the trained group. Moreover, sympathetic tone was positively correlated with resting HR (r=0.7, P<0.05). The additional arterial pressure increase in hypertensive rats caused by ovarian hormone deprivation was attenuated by moderate-intensity dynamic resistance training. This benefit may be associated with resting bradycardia and reduced cardiac sympathetic tone after training, which suggests potential benefits of resistance exercise for the management of hypertension after ovarian hormone deprivation.

  3. Dynamic resistance training decreases sympathetic tone in hypertensive ovariectomized rats

    Directory of Open Access Journals (Sweden)

    G.L. Shimojo

    2015-06-01

    Full Text Available The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC, sedentary hypertensive (SH, sedentary hypertensive ovariectomized (SHO, and resistance-trained hypertensive ovariectomized (RTHO. Resistance exercise training was performed on a vertical ladder (5 days/week, 8 weeks at 40-60% maximal load. Direct arterial pressure was recorded. Vagal and sympathetic tones were measured by heart rate (HR responses to methylatropine (3 mg/kg, iv and propranolol (4 mg/kg, iv. Ovariectomy resulted in additional increases in blood pressure in hypertensive rats and was associated with decreased vagal tone. Resistance exercise trained rats had lower mean arterial pressure than untrained rats (RTHO: 159±2.2 vs SHO: 177±3.4 mmHg, as well as resting bradycardia (RTHO: 332±9.0 vs SHO: 356±5 bpm. Sympathetic tone was also lower in the trained group. Moreover, sympathetic tone was positively correlated with resting HR (r=0.7, P<0.05. The additional arterial pressure increase in hypertensive rats caused by ovarian hormone deprivation was attenuated by moderate-intensity dynamic resistance training. This benefit may be associated with resting bradycardia and reduced cardiac sympathetic tone after training, which suggests potential benefits of resistance exercise for the management of hypertension after ovarian hormone deprivation.

  4. Dynamic resistance training decreases sympathetic tone in hypertensive ovariectomized rats

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and resistance-trained hypertensive ovariectomized (RTHO). Resistance exercise training was performed on a vertical ladder (5 days/week, 8 weeks) at 40-60% maximal load. Direct arterial pressure was recorded. Vagal and sympathetic tones were measured by heart rate (HR) responses to methylatropine (3 mg/kg, iv) and propranolol (4 mg/kg, iv). Ovariectomy resulted in additional increases in blood pressure in hypertensive rats and was associated with decreased vagal tone. Resistance exercise trained rats had lower mean arterial pressure than untrained rats (RTHO: 159±2.2 vs SHO: 177±3.4 mmHg), as well as resting bradycardia (RTHO: 332±9.0 vs SHO: 356±5 bpm). Sympathetic tone was also lower in the trained group. Moreover, sympathetic tone was positively correlated with resting HR (r=0.7, P<0.05). The additional arterial pressure increase in hypertensive rats caused by ovarian hormone deprivation was attenuated by moderate-intensity dynamic resistance training. This benefit may be associated with resting bradycardia and reduced cardiac sympathetic tone after training, which suggests potential benefits of resistance exercise for the management of hypertension after ovarian hormone deprivation

  5. Effect of Long-Term Physical Activity Practice after Cardiac Rehabilitation on Some Risk Factors

    Science.gov (United States)

    Freyssin, Celine, Jr.; Blanc, Philippe; Verkindt, Chantal; Maunier, Sebastien; Prieur, Fabrice

    2011-01-01

    The objective of this study was to evaluate the effects of long-term physical activity practice after a cardiac rehabilitation program on weight, physical capacity and arterial compliance. The Dijon Physical Activity Score was used to identify two groups: sedentary and active. Weight, distance at the 6-min walk test and the small artery elasticity…

  6. P2 receptors in the central and peripheral nervous systems modulating sympathetic vasomotor tone.

    Science.gov (United States)

    Ralevic, V

    2000-07-01

    Arterial pressure depends on the level of activity of sympathetic vasoconstrictor outflow to blood vessels. This activity is generated in the central nervous system, and involves inputs from a variety of brain regions projecting to sympathetic preganglionic neurones. Of especial interest are a group of neurones in the rostral ventrolateral medulla (RVLM), as they have been demonstrated to have a fundamental role in reflex regulation of the cardiovascular system, and in generation of tonic drive to sympathetic outflow. Sympathetic outflow to blood vessels is additionally modulated at sympathetic ganglia, and at the peripheral terminals of sympathetic nerves. This review considers the role of P2 purine receptors in this neural pathway. Ionotropic P2X receptors are expressed in the RVLM, in sympathetic ganglia, and at the sympathetic neuromuscular junction, and mediate fast excitatory neurotransmission, indicating a general role for ATP as a regulator of sympathetic vasomotor tone. P2Y receptors couple to G proteins and mediate slower signalling to ATP; they have been reported to inhibit prejunctionally neurotransmission at the peripheral terminals of sympathetic nerves, but little is known about their possible role in the central nervous system and in sympathetic ganglia.

  7. Hypoxia preconditioned mesenchymal stem cells prevent cardiac fibroblast activation and collagen production via leptin.

    Directory of Open Access Journals (Sweden)

    Panpan Chen

    Full Text Available Activation of cardiac fibroblasts into myofibroblasts constitutes a key step in cardiac remodeling after myocardial infarction (MI, due to interstitial fibrosis. Mesenchymal stem cells (MSCs have been shown to improve post-MI remodeling an effect that is enhanced by hypoxia preconditioning (HPC. Leptin has been shown to promote cardiac fibrosis. The expression of leptin is significantly increased in MSCs after HPC but it is unknown whether leptin contributes to MSC therapy or the fibrosis process. The objective of this study was to determine whether leptin secreted from MSCs modulates cardiac fibrosis.Cardiac fibroblast (CF activation was induced by hypoxia (0.5% O2. The effects of MSCs on fibroblast activation were analyzed by co-culturing MSCs with CFs, and detecting the expression of α-SMA, SM22α, and collagen IαI in CFs by western blot, immunofluorescence and Sirius red staining. In vivo MSCs antifibrotic effects on left ventricular remodeling were investigated using an acute MI model involving permanent ligation of the left anterior descending coronary artery.Co-cultured MSCs decreased fibroblast activation and HPC enhanced the effects. Leptin deficit MSCs from Ob/Ob mice did not decrease fibroblast activation. Consistent with this, H-MSCs significantly inhibited cardiac fibrosis after MI and mediated decreased expression of TGF-β/Smad2 and MRTF-A in CFs. These effects were again absent in leptin-deficient MSCs.Our data demonstrate that activation of cardiac fibroblast was inhibited by MSCs in a manner that was leptin-dependent. The mechanism may involve blocking TGF-β/Smad2 and MRTF-A signal pathways.

  8. Metformin attenuates pressure overload-induced cardiac hypertrophy via AMPK activation

    Institute of Scientific and Technical Information of China (English)

    Yong-nan FU; Han XIAO; Xiao-wei MA; Sheng-yang JIANG; Ming XU; You-yi ZHANG

    2011-01-01

    Aim: To identify the role of metformin in cardiac hypertrophy and investigate the possible mechanism underlying this effect.Methods: Wild type and AMPKα2 knockout (AMPKα2-/-) littermates were subjected to left ventricular pressure overload caused by evaluated using echocardiography and anatomic and histological methods. The antihypertrophic mechanism of metformin was analyzed using Western blotting.Results: Metformin significantly attenuated cardiac hypertrophy induced by pressure overload in wild type mice, but the antihypertrophic actions of metformin were ablated in AMPKx2-/- mice. Furthermore, metformin suppressed the phosphorylation of Akt/protein kinase B (AKT) and mammalian target of rapamycin (mTOR) in response to pressure overload in wild type mice, but not in AMPKα2-/-mice.Conclusion: Long-term administration of metformin may attenuate cardiac hypertrophy induced by pressure overload in nondiabetic mice, and this attenuation is highly dependent on AMPK activation. These findings may provide a potential therapy for patients at risk of developing pathological cardiac hypertrophy.

  9. An active contour framework based on the Hermite transform for shape segmentation of cardiac MR images

    Science.gov (United States)

    Barba-J, Leiner; Escalante-Ramírez, Boris

    2016-04-01

    Early detection of cardiac affections is fundamental to address a correct treatment that allows preserving the patient's life. Since heart disease is one of the main causes of death in most countries, analysis of cardiac images is of great value for cardiac assessment. Cardiac MR has become essential for heart evaluation. In this work we present a segmentation framework for shape analysis in cardiac magnetic resonance (MR) images. The method consists of an active contour model which is guided by the spectral coefficients obtained from the Hermite transform (HT) of the data. The HT is used as model to code image features of the analyzed images. Region and boundary based energies are coded using the zero and first order coefficients. An additional shape constraint based on an elliptical function is used for controlling the active contour deformations. The proposed framework is applied to the segmentation of the endocardial and epicardial boundaries of the left ventricle using MR images with short axis view. The segmentation is sequential for both regions: the endocardium is segmented followed by the epicardium. The algorithm is evaluated with several MR images at different phases of the cardiac cycle demonstrating the effectiveness of the proposed method. Several metrics are used for performance evaluation.

  10. Activation of mitochondrial calpain and increased cardiac injury: beyond AIF release.

    Science.gov (United States)

    Thompson, Jeremy; Hu, Ying; Lesnefsky, Edward J; Chen, Qun

    2016-02-01

    Calpain 1 (CPN1) is a ubiquitous cysteine protease that exists in both cytosol and cardiac mitochondria. Mitochondrial CPN1 (mit-CPN1) is located in the intermembrane space and matrix. Activation of mit-CPN1 within the intermembrane space increases cardiac injury by releasing apoptosis-inducing factor from mitochondria during ischemia-reperfusion (IR). We asked if activation of mit-CPN1 is involved in mitochondrial injury during IR. MDL-28170 (MDL) was used to inhibit CPN1 in buffer-perfused hearts following 25-min ischemia and 30-min reperfusion. MDL treatment decreased the release of lactate dehydrogenase into coronary effluent compared with untreated hearts, indicating that inhibition of CPN1 decreases cardiac injury. MDL also prevented the cleavage of spectrin (a substrate of CPN1) in cytosol during IR, supporting that MDL treatment decreased cytosolic calpain activation. In addition, MDL markedly improved calcium retention capacity compared with untreated heart, suggesting that MDL treatment decreases mitochondrial permeability transition pore opening. In addition, we found that IR led to decreased complex I activity, whereas inhibition of mit-CPN1 using MDL protected complex I. Pyruvate dehydrogenase content was decreased following IR. However, pyruvate dehydrogenase content was preserved in MDL-treated mitochondria. Taken together, MDL treatment decreased cardiac injury during IR by inhibiting both cytosolic and mit-CPN1. Activation of mit-CPN1 increases cardiac injury during IR by sensitizing mitochondrial permeability transition pore opening and impairing mitochondrial metabolism through damage of complex I. PMID:26637561

  11. Factors influencing the cardiac MIBG accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Takatsu, Hisato; Fujiwara, Hisayoshi [Gifu Univ. (Japan). School of Medicine

    1997-02-01

    Following factors possibly influencing the cardiac MIBG accumulation were examined mainly in mice. 1. The specific activity of the MIBG (meta-iodo-benzyl guanidine) on the neuronal and non-neuronal fractions. 2. Motor restriction stress on MIBG accumulation and washout. 3. Loading and restriction of sodium chloride on the accumulation and effect of suppression of renin-angiotensin system. 4. Examinations in Dahl rats. 125I- or 131I-MIBG was intravenously administered to mice at 74 kBq. At 30 min or 4 hr after administration, mice were sacrificed and their left ventricles were dissected out for measurement of radioactivity in a liquid scintillation counter. Salt-sensitive and -resistant Dahl rats were given with 37 MBq of 123I-MIBG and cardiac radioactivity was measured externally for calculation of washout. Factors examined were found highly correlated with the accumulation of MIBG and measurement of its washout was considered useful for evaluating sympathetic activity. (K.H.)

  12. Activation of the Cardiac Renin-Angiotensin System in High Oxygen-Exposed Newborn Rats: Angiotensin Receptor Blockade Prevents the Developmental Programming of Cardiac Dysfunction.

    Science.gov (United States)

    Bertagnolli, Mariane; Dios, Anne; Béland-Bonenfant, Sarah; Gascon, Gabrielle; Sutherland, Megan; Lukaszewski, Marie-Amélie; Cloutier, Anik; Paradis, Pierre; Schiffrin, Ernesto L; Nuyt, Anne Monique

    2016-04-01

    Newborn rats exposed to high oxygen (O2), mimicking preterm birth-related neonatal stress, develop later in life cardiac hypertrophy, dysfunction, fibrosis, and activation of the renin-angiotensin system. Cardiac renin-angiotensin system activation in O2-exposed adult rats is characterized by an imbalance in angiotensin (Ang) receptors type 1/2 (AT1/2), with prevailing AT1 expression. To study the role of renin-angiotensin system in the developmental programming of cardiac dysfunction, we assessed Ang receptor expression during neonatal high O2 exposure and whether AT1 receptor blockade prevents cardiac alterations in early adulthood. Sprague-Dawley newborn rats were kept with their mother in 80% O2 or room air (control) from days 3 to 10 (P3-P10) of life. Losartan or water was administered by gavage from P8 to P10 (n=9/group). Rats were studied at P3 (before O2 exposure), P5, P10 (end of O2), and P28. Losartan treatment had no impact on growth or kidney development. AT1 and Ang type 2 receptors were upregulated in the left ventricle by high O2 exposure (P5 and P10), which was prevented by Losartan treatment at P10. Losartan prevented the cardiac AT1/2 imbalance at P28. Losartan decreased cardiac hypertrophy and fibrosis and improved left ventricle fraction of shortening in P28 O2-exposed rats, which was associated with decreased oxidation of calcium/calmodulin-dependent protein kinase II, inhibition of the transforming growth factor-β/SMAD3 pathway, and upregulation of cardiac angiotensin-converting enzyme 2. In conclusion, short-term Ang II blockade during neonatal high O2 prevents the development of cardiac alterations later in life in rats. These findings highlight the key role of neonatal renin-angiotensin system activation in the developmental programming of cardiac dysfunction induced by deleterious neonatal conditions. PMID:26857347

  13. Activation of the Cardiac Renin-Angiotensin System in High Oxygen-Exposed Newborn Rats: Angiotensin Receptor Blockade Prevents the Developmental Programming of Cardiac Dysfunction.

    Science.gov (United States)

    Bertagnolli, Mariane; Dios, Anne; Béland-Bonenfant, Sarah; Gascon, Gabrielle; Sutherland, Megan; Lukaszewski, Marie-Amélie; Cloutier, Anik; Paradis, Pierre; Schiffrin, Ernesto L; Nuyt, Anne Monique

    2016-04-01

    Newborn rats exposed to high oxygen (O2), mimicking preterm birth-related neonatal stress, develop later in life cardiac hypertrophy, dysfunction, fibrosis, and activation of the renin-angiotensin system. Cardiac renin-angiotensin system activation in O2-exposed adult rats is characterized by an imbalance in angiotensin (Ang) receptors type 1/2 (AT1/2), with prevailing AT1 expression. To study the role of renin-angiotensin system in the developmental programming of cardiac dysfunction, we assessed Ang receptor expression during neonatal high O2 exposure and whether AT1 receptor blockade prevents cardiac alterations in early adulthood. Sprague-Dawley newborn rats were kept with their mother in 80% O2 or room air (control) from days 3 to 10 (P3-P10) of life. Losartan or water was administered by gavage from P8 to P10 (n=9/group). Rats were studied at P3 (before O2 exposure), P5, P10 (end of O2), and P28. Losartan treatment had no impact on growth or kidney development. AT1 and Ang type 2 receptors were upregulated in the left ventricle by high O2 exposure (P5 and P10), which was prevented by Losartan treatment at P10. Losartan prevented the cardiac AT1/2 imbalance at P28. Losartan decreased cardiac hypertrophy and fibrosis and improved left ventricle fraction of shortening in P28 O2-exposed rats, which was associated with decreased oxidation of calcium/calmodulin-dependent protein kinase II, inhibition of the transforming growth factor-β/SMAD3 pathway, and upregulation of cardiac angiotensin-converting enzyme 2. In conclusion, short-term Ang II blockade during neonatal high O2 prevents the development of cardiac alterations later in life in rats. These findings highlight the key role of neonatal renin-angiotensin system activation in the developmental programming of cardiac dysfunction induced by deleterious neonatal conditions.

  14. A critical role of cardiac fibroblast-derived exosomes in activating renin angiotensin system in cardiomyocytes.

    Science.gov (United States)

    Lyu, Linmao; Wang, Hui; Li, Bin; Qin, Qingyun; Qi, Lei; Nagarkatti, Mitzi; Nagarkatti, Prakash; Janicki, Joseph S; Wang, Xing Li; Cui, Taixing

    2015-12-01

    Chronic activation of the myocardial renin angiotensin system (RAS) elevates the local level of angiotensin II (Ang II) thereby inducing pathological cardiac hypertrophy, which contributes to heart failure. However, the precise underlying mechanisms have not been fully delineated. Herein we report a novel paracrine mechanism between cardiac fibroblasts (CF)s and cardiomyocytes whereby Ang II induces pathological cardiac hypertrophy. In cultured CFs, Ang II treatment enhanced exosome release via the activation of Ang II receptor types 1 (AT1R) and 2 (AT2R), whereas lipopolysaccharide, insulin, endothelin (ET)-1, transforming growth factor beta (TGFβ)1 or hydrogen peroxide did not. The CF-derived exosomes upregulated the expression of renin, angiotensinogen, AT1R, and AT2R, downregulated angiotensin-converting enzyme 2, and enhanced Ang II production in cultured cardiomyocytes. In addition, the CF exosome-induced cardiomyocyte hypertrophy was blocked by both AT1R and AT2R antagonists. Exosome inhibitors, GW4869 and dimethyl amiloride (DMA), inhibited CF-induced cardiomyocyte hypertrophy with little effect on Ang II-induced cardiomyocyte hypertrophy. Mechanistically, CF exosomes upregulated RAS in cardiomyocytes via the activation of mitogen-activated protein kinases (MAPKs) and Akt. Finally, Ang II-induced exosome release from cardiac fibroblasts and pathological cardiac hypertrophy were dramatically inhibited by GW4869 and DMA in mice. These findings demonstrate that Ang II stimulates CFs to release exosomes, which in turn increase Ang II production and its receptor expression in cardiomyocytes, thereby intensifying Ang II-induced pathological cardiac hypertrophy. Accordingly, specific targeting of Ang II-induced exosome release from CFs may serve as a novel therapeutic approach to treat cardiac pathological hypertrophy and heart failure.

  15. Annexin A7 deficiency potentiates cardiac NFAT activity promoting hypertrophic signaling

    Energy Technology Data Exchange (ETDEWEB)

    Voelkl, Jakob; Alesutan, Ioana; Pakladok, Tatsiana; Viereck, Robert; Feger, Martina; Mia, Sobuj [Department of Physiology, University of Tübingen, Tübingen (Germany); Schönberger, Tanja [Department of Cardiology and Cardiovascular Medicine, University of Tübingen, Tübingen (Germany); Noegel, Angelika A. [Center for Biochemistry, Institute of Biochemistry I, University of Cologne, Köln (Germany); Gawaz, Meinrad [Department of Cardiology and Cardiovascular Medicine, University of Tübingen, Tübingen (Germany); Lang, Florian, E-mail: florian.lang@uni-tuebingen.de [Department of Physiology, University of Tübingen, Tübingen (Germany)

    2014-02-28

    Highlights: • Cardiac Anxa7 expression was up-regulated following TAC. • The hypertrophic response following TAC was augmented in Anxa7-deficient mice. • Silencing of Anxa7 increased indicators of HL-1 cardiomyocytes hypertrophy. • Silencing of Anxa7 induced Nfatc1 nuclear translocation. • Silencing of Anxa7 enhanced NFAT-dependent transcriptional activity. - Abstract: Annexin A7 (Anxa7) is a cytoskeletal protein interacting with Ca{sup 2+} signaling which in turn is a crucial factor for cardiac remodeling following cardiac injury. The present study explored whether Anxa7 participates in the regulation of cardiac stress signaling. To this end, mice lacking functional Anxa7 (anxa7{sup −/−}) and wild-type mice (anxa7{sup +/+}) were investigated following pressure overload by transverse aortic constriction (TAC). In addition, HL-1 cardiomyocytes were silenced with Anxa7 siRNA and treated with isoproterenol. Transcript levels were determined by quantitative RT-PCR, transcriptional activity by luciferase reporter assay and protein abundance by Western blotting and confocal microscopy. As a result, TAC treatment increased the mRNA and protein levels of Anxa7 in wild-type mice. Moreover, TAC increased heart weight to body weight ratio and the cardiac mRNA levels of αSka, Nppb, Col1a1, Col3a1 and Rcan1, effects more pronounced in anxa7{sup −/−} mice than in anxa7{sup +/+} mice. Silencing of Anxa7 in HL-1 cardiomyocytes significantly increased nuclear localization of Nfatc1. Furthermore, Anxa7 silencing increased NFAT-dependent transcriptional activity as well as αSka, Nppb, and Rcan1 mRNA levels both, under control conditions and following β-adrenergic stimulation by isoproterenol. These observations point to an important role of annexin A7 in the regulation of cardiac NFAT activity and hypertrophic response following cardiac stress conditions.

  16. Effects of moxonidine on sympathetic nervous system activity: An update on metabolism, cardio, and other target-organ protection

    Directory of Open Access Journals (Sweden)

    Eleni F Karlafti

    2013-01-01

    Full Text Available Moxonidine is the newest, second-generation, centrally acting antihypertensive agent. It has selective agonist activity at imidazoline I1 receptors and less adverse effects than the other centrally acting drugs. This fact authorizes the frequent use of moxonidine in clinical practice, as monotherapy or in combination with other antihypertensive agents. Also, moxonidine has beneficial effects in obese and metabolic syndrome and in target-organs, such as heart and kidneys.

  17. Changes in Sympathetic Nervous System Activity are Associated with Changes in Sexual Wellbeing in Women with a History of Childhood Sexual Abuse

    Science.gov (United States)

    Lorenz, Tierney K.; Harte, Christopher B.; Meston, Cindy M.

    2015-01-01

    Introduction Women with histories of childhood sexual abuse (CSA) have higher rates of sexual difficulties, as well as high sympathetic nervous system (SNS) response to sexual stimuli. Aim To examine whether treatment-related changes in autonomic balance, as indexed by heart rate variability (HRV), were associated with changes in sexual arousal and orgasm function. Methods In Study 1, we measured HRV while writing a sexual essay in 42 healthy, sexually functional women without any history of sexual trauma. These data, along with demographics, were used to develop HRV norms equations. In Study 2, 136 women with a history of CSA were randomized to one of three active expressive writing treatments that focused on their trauma, sexuality, or daily life (control condition). We recorded HRV while writing a sexual essay at pre-treatment, post-treatment, and 2 week, 1 month, and 6 month follow-ups; we also calculated the expected HRV for each participant based on the norms equations from Study 1. Main Outcome Measures Heart rate variability, Female Sexual Function Index (FSFI), Sexual Satisfaction Scale – Women (SSS-W) Results The difference between expected and observed HRV decreased over time, indicating that, post-treatment, CSA survivors displayed HRV closer to the expected HRV of a demographics-matched woman with no history of sexual trauma. Also, over time, participants whose HRV became less dysregulated showed the biggest gains in sexual arousal and orgasm function. These effects were consistent across condition. Conclusions Treatments that reduce autonomic imbalance may improve sexual wellbeing among CSA populations. PMID:25963394

  18. Obesity-Related Metabolic Syndrome: Mechanisms of Sympathetic Overactivity

    OpenAIRE

    Maria Paola Canale; Simone Manca di Villahermosa; Giuliana Martino; Valentina Rovella; Annalisa Noce; Antonino De Lorenzo; Nicola Di Daniele

    2013-01-01

    The prevalence of the metabolic syndrome has increased worldwide over the past few years. Sympathetic nervous system overactivity is a key mechanism leading to hypertension in patients with the metabolic syndrome. Sympathetic activation can be triggered by reflex mechanisms as arterial baroreceptor impairment, by metabolic factors as insulin resistance, and by dysregulated adipokine production and secretion from visceral fat with a mainly permissive role of leptin and antagonist role of adipo...

  19. Sympathetic and sensory innervation of brown adipose tissue

    OpenAIRE

    Bartness, TJ; Vaughan, CH; Song, CK

    2010-01-01

    The innervation of brown adipose tissue (BAT) by the sympathetic nervous system (SNS) is incontrovertible and, with its activation, functions as the principal, if not exclusive, stimulator of BAT thermogenesis. The parasympathetic innervation of BAT only appears in two minor BAT depots, but not in the major interscapular BAT (IBAT) depot. BAT thermogenesis is triggered by the release of norepinephrine from its sympathetic nerve terminals, stimulating β3-adrenoceptors that turns on a cascade o...

  20. Glutamate and GABA in Vestibulo-Sympathetic Pathway Neurons

    OpenAIRE

    Holstein, Gay R.; Friedrich, Victor L. Jr.; Martinelli, Giorgio P.

    2016-01-01

    The vestibulo-sympathetic reflex (VSR) actively modulates blood pressure during changes in posture. This reflex allows humans to stand up and quadrupeds to rear or climb without a precipitous decline in cerebral perfusion. The VSR pathway conveys signals from the vestibular end organs to the caudal vestibular nuclei. These cells, in turn, project to pre-sympathetic neurons in the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively). The present study assessed glutamate- and ...

  1. Sympathetic β-adrenergic mechanism in pudendal inhibition of nociceptive and non-nociceptive reflex bladder activity.

    Science.gov (United States)

    Kadow, Brian T; Lyon, Timothy D; Zhang, Zhaocun; Lamm, Vladimir; Shen, Bing; Wang, Jicheng; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2016-07-01

    This study investigated the role of the hypogastric nerve and β-adrenergic mechanisms in the inhibition of nociceptive and non-nociceptive reflex bladder activity induced by pudendal nerve stimulation (PNS). In α-chloralose-anesthetized cats, non-nociceptive reflex bladder activity was induced by slowly infusing saline into the bladder, whereas nociceptive reflex bladder activity was induced by replacing saline with 0.25% acetic acid (AA) to irritate the bladder. PNS was applied at multiple threshold (T) intensities for inducing anal sphincter twitching. During saline infusion, PNS at 2T and 4T significantly (P < 0.01) increased bladder capacity to 184.7 ± 12.6% and 214.5 ± 10.4% of the control capacity. Propranolol (3 mg/kg iv) had no effect on PNS inhibition, but 3-[(2-methyl-4-thiazolyl)ethynyl]pyridine (MTEP; 1-3 mg/kg iv) significantly (P < 0.05) reduced the inhibition. During AA irritation, the control bladder capacity was significantly (P < 0.05) reduced to ∼22% of the saline control capacity. PNS at 2T and 4T significantly (P < 0.01) increased bladder capacity to 406.8 ± 47% and 415.8 ± 46% of the AA control capacity. Propranolol significantly (P < 0.05) reduced the bladder capacity to 276.3% ± 53.2% (at 2T PNS) and 266.5 ± 72.4% (at 4T PNS) of the AA control capacity, whereas MTEP (a metabotropic glutamate 5 receptor antagonist) removed the residual PNS inhibition. Bilateral transection of the hypogastric nerves produced an effect similar to that produced by propranolol. This study indicates that hypogastric nerves and a β-adrenergic mechanism in the detrusor play an important role in PNS inhibition of nociceptive but not non-nociceptive reflex bladder activity. In addition to this peripheral mechanism, a central nervous system mechanism involving metabotropic glutamate 5 receptors also has a role in PNS inhibition. PMID:27170683

  2. Active cardiac model and its application on structure detection from early fetal ultrasound sequences.

    Science.gov (United States)

    Deng, Yinhui; Wang, Yuanyuan; Shen, Yuzhong; Chen, Ping

    2012-04-01

    The structure of an early fetal heart provides vital information for the diagnosis of fetus defects. However, early fetal hearts are difficult to detect due to their relatively small size and the low signal-to-noise ratio of ultrasound images. In this paper, a novel method is proposed for automatic detection of early fetal cardiac structure from ultrasound images. The proposed method consists of two major parts which are the preprocessing phase and the active cardiac model: (1) The preprocessing phase consists of two sub-steps. (a) The region of interest is first automatically selected based on an accumulated motion image, which is able to represent the motion information of the fetal heart more accurately. (b) Then by combining Rayleigh-trimmed filter and anisotropic diffusion in 3-dimensional space, a despeckling method is developed to suppress the speckle noise and emphasize the motion information for subsequent cardiac structure detection. (2) The active cardiac model is proposed for the detection of fetal heart structure, which is a key contribution of this paper. It takes into account both the structure and motion information of fetal hearts simultaneously. Both learning and inference of the active cardiac model are described in the paper. Experiments on seven ultrasound sequences demonstrate the effectiveness of the proposed method. PMID:21620676

  3. UCP3 Regulates Single-Channel Activity of the Cardiac mCa1.

    Science.gov (United States)

    Motloch, Lukas J; Gebing, Tina; Reda, Sara; Schwaiger, Astrid; Wolny, Martin; Hoppe, Uta C

    2016-08-01

    Mitochondrial Ca(2+) uptake (mCa(2+) uptake) is thought to be mediated by the mitochondrial Ca(2+) uniporter (MCU). UCP2 and UCP3 belong to a superfamily of mitochondrial ion transporters. Both proteins are expressed in the inner mitochondrial membrane of the heart. Recently, UCP2 was reported to modulate the function of the cardiac MCU related channel mCa1. However, the possible role of UCP3 in modulating cardiac mCa(2+) uptake via the MCU remains inconclusive. To understand the role of UCP3, we analyzed cardiac mCa1 single-channel activity in mitoplast-attached single-channel recordings from isolated murine cardiac mitoplasts, from adult wild-type controls (WT), and from UCP3 knockout mice (UCP3(-/-)). Single-channel registrations in UCP3(-/-) confirmed a murine voltage-gated Ca(2+) channel, i.e., mCa1, which was inhibited by Ru360. Compared to WT, mCa1 in UCP3(-/-) revealed similar single-channel characteristics. However, in UCP3(-/-) the channel exhibited decreased single-channel activity, which was insensitive to adenosine triphosphate (ATP) inhibition. Our results suggest that beyond UCP2, UCP3 also exhibits regulatory effects on cardiac mCa1/MCU function. Furthermore, we speculate that UCP3 might modulate previously described inhibitory effects of ATP on mCa1/MCU activity as well.

  4. Obesity-Related Metabolic Syndrome: Mechanisms of Sympathetic Overactivity

    Directory of Open Access Journals (Sweden)

    Maria Paola Canale

    2013-01-01

    Full Text Available The prevalence of the metabolic syndrome has increased worldwide over the past few years. Sympathetic nervous system overactivity is a key mechanism leading to hypertension in patients with the metabolic syndrome. Sympathetic activation can be triggered by reflex mechanisms as arterial baroreceptor impairment, by metabolic factors as insulin resistance, and by dysregulated adipokine production and secretion from visceral fat with a mainly permissive role of leptin and antagonist role of adiponectin. Chronic sympathetic nervous system overactivity contributes to a further decline of insulin sensitivity and creates a vicious circle that may contribute to the development of hypertension and of the metabolic syndrome and favor cardiovascular and kidney disease. Selective renal denervation is an emerging area of interest in the clinical management of obesity-related hypertension. This review focuses on current understanding of some mechanisms through which sympathetic overactivity may be interlaced to the metabolic syndrome, with particular regard to the role of insulin resistance and of some adipokines.

  5. Sympathetic re-innervation of myocardium after liver transplant in the hereditary amyloid neuropathy

    International Nuclear Information System (INIS)

    The hereditary amyloid neuropathy (HAN) is characterized by a progressive sensory-motor poly-neuropathy and a dysautonomia with myocardium sympathetic denervation. This is established by MIBL scintigraphy and may enhance the troubles of conduction and of cardiac rhythm. The amyloid deposits are constituted of anomalous pre-albumin fabricated by liver. The hepatic transplant (HT) is the only known treatment. Four patients (GI: 39 ± 5 years) have been studied by MIBG scintigraphy, 2.2 ± 0.7 years after HT, and compared with 12 patients (GII: 39 ± 12 years) studied before HT. The left ventricular function, the coronary arteries and the at-rest scintigraphy with thallium were normal for all of them. The cardiac capture of MIBG, evaluated by the cardio-mediastinal activity ratio (C/M), measured on an anterior thoracic planar acquisition performed 4 hours after the intravenous injection of 300 MBq, was higher for GI than for GII (1.49 ± 0.12 vs 1.29 ± 0.13, p 0.02). The washouts (4 h / 20 min) were not different. In tomography, the patients of GI presented focal anomalies with a more-or-less extended apical defect, a satisfying fixation of the basal half of the anterior wall, more-or-less overflowing the septal and lateral walls, and for 2 patients, a satisfying inferior fixation. On the contrary, 9/12 patients of GII have had a diffuse absence of fixation, the other three heaving a satisfying antero-basal fixation (χ2, p = 0.05). The results are not explained by difference of severity or evolution duration of HAN. Thus, it appears that there exists a sympathetic re-innervation of myocardium after HT in the HAN, debuting by the heart base, similarly with the effect of anatomic interruption of innervation in cardiac transplants

  6. High sugar intake exacerbates cardiac reperfusion injury in perinatal taurine depleted adult rats

    OpenAIRE

    Kulthinee Supaporn; Wyss J Michael; Jirakulsomchok Dusit; Roysommuti Sanya

    2010-01-01

    Abstract Perinatal taurine depletion and high sugar diets blunted baroreflex function and heightens sympathetic nerve activity in adult rats. Cardiac ischemia/reperfusion also produces these disorders and taurine treatment appears to improve these effects. This study tests the hypothesis that perinatal taurine exposure predisposes recovery from reperfusion injury in rats on either a basal or high sugar diet. Female Sprague-Dawley rats were fed normal rat chow with 3% beta-alanine (taurine dep...

  7. Role of the Sympathetic Nervous System in Stress-Mediated Cardiovascular Disease.

    Science.gov (United States)

    Hering, Dagmara; Lachowska, Kamila; Schlaich, Markus

    2015-10-01

    A high incidence of acute cardiovascular events and sudden cardiac death following unexpected acute emotional stress or a natural catastrophic disaster has been well-documented over the past decades. Chronic psychosocial factors have been shown to be directly linked to the development of hypertension, cardiovascular disease and stroke. Activation of various neurogenic pathways is an important mediator of acute and chronic stress-induced hypertension and heart disease. Heightened sympathetic activation has been shown to be a critical contributor linking psychogenic effects on cardiovascular regulation to serious and often fatal CV outcomes. Accordingly, several therapeutic approaches that attenuate autonomic imbalance via modulation of increased sympathetic outflow by either non-pharmacological or interventional means have been shown to alleviate clinical symptoms. Likewise stress reduction per se achieved with transcendental medicine has been linked to improved patient outcomes. Therapies that oppose adrenergic activity and/or have the potential to attenuate negative emotions are likely to reduce cardiovascular risk and its adverse consequences attributable to chronic mental stress. PMID:26318888

  8. Role of the Sympathetic Nervous System in Stress-Mediated Cardiovascular Disease.

    Science.gov (United States)

    Hering, Dagmara; Lachowska, Kamila; Schlaich, Markus

    2015-10-01

    A high incidence of acute cardiovascular events and sudden cardiac death following unexpected acute emotional stress or a natural catastrophic disaster has been well-documented over the past decades. Chronic psychosocial factors have been shown to be directly linked to the development of hypertension, cardiovascular disease and stroke. Activation of various neurogenic pathways is an important mediator of acute and chronic stress-induced hypertension and heart disease. Heightened sympathetic activation has been shown to be a critical contributor linking psychogenic effects on cardiovascular regulation to serious and often fatal CV outcomes. Accordingly, several therapeutic approaches that attenuate autonomic imbalance via modulation of increased sympathetic outflow by either non-pharmacological or interventional means have been shown to alleviate clinical symptoms. Likewise stress reduction per se achieved with transcendental medicine has been linked to improved patient outcomes. Therapies that oppose adrenergic activity and/or have the potential to attenuate negative emotions are likely to reduce cardiovascular risk and its adverse consequences attributable to chronic mental stress.

  9. Follistatin-like 1 promotes cardiac fibroblast activation and protects the heart from rupture.

    Science.gov (United States)

    Maruyama, Sonomi; Nakamura, Kazuto; Papanicolaou, Kyriakos N; Sano, Soichi; Shimizu, Ippei; Asaumi, Yasuhide; van den Hoff, Maurice J; Ouchi, Noriyuki; Recchia, Fabio A; Walsh, Kenneth

    2016-01-01

    Follistatin-like 1 (Fstl1) is a secreted protein that is acutely induced in heart following myocardial infarction (MI). In this study, we investigated cell type-specific regulation of Fstl1 and its function in a murine model of MI Fstl1 was robustly expressed in fibroblasts and myofibroblasts in the infarcted area compared to cardiac myocytes. The conditional ablation of Fstl1 in S100a4-expressing fibroblast lineage cells (Fstl1-cfKO mice) led to a reduction in injury-induced Fstl1 expression and increased mortality due to cardiac rupture during the acute phase. Cardiac rupture was associated with a diminished number of myofibroblasts and decreased expression of extracellular matrix proteins. The infarcts of Fstl1-cfKO mice displayed weaker birefringence, indicative of thin and loosely packed collagen. Mechanistically, the migratory and proliferative capabilities of cardiac fibroblasts were attenuated by endogenous Fstl1 ablation. The activation of cardiac fibroblasts by Fstl1 was mediated by ERK1/2 but not Smad2/3 signaling. This study reveals that Fstl1 is essential for the acute repair of the infarcted myocardium and that stimulation of early fibroblast activation is a novel function of Fstl1. PMID:27234440

  10. Reflex Sympathetic Dystrophy in Children

    OpenAIRE

    Adnan Ayvaz

    2013-01-01

       Reflex sympathetic dystrophy (chronic regional pain syndrome) isn’t frequently encountered in practical pediatrics and childhood. Reflex sympathetic dystrophy syndrome (RSD) is a disorder characterized by widespread localized pain, often along with swelling, discoloration, trophic changes and autonomic abnormalities such as vasomotor disorders. Its etio-pathogenesis hasn’t been completely determined.The disease can form in an area innerved by a partially damaged nerve...

  11. Changes in the cardiac muscle electric activity as a result of Coronary Artery Bypass Graft operation

    Science.gov (United States)

    Grajek, Magdalena; Krzyminiewski, Ryszard; Kalawski, Ryszard; Kulczak, Mariusz

    2008-01-01

    Many bioelectric signals have a complex internal structure that can be a rich source of information on the tissue or cell processes. The structure of such signals can be analysed in detail by applying digital methods of signal processing. Therefore, of substantial use in diagnosis of the coronary arterial disease is the method of digital enhancement of increasing signal resolution ECG (NURSE-ECG), permitting detection of temporary changes in the electric potentials in the cardiac muscle in the process of depolarisation. Thanks to the application of NURSE-ECG it has become possible to detect relatively small changes in the electric activity of particular fragments of the cardiac muscle undetectable by the standard ECG method, caused by ischemia, the effect of a drug or infarct. The aim of this study was to identify and analyse changes in the electric activity of the cardiac muscle as a result of the Coronary Artery Bypass Graft (CABG) operation. In this study the method of NURSE-ECG has been applied in order to identify and analyse changes in the electric activity of the cardiac muscle as a result of the CABG operation. In the study performed in cooperation of the Institute of Physics Adam Mickiewicz University and the Strus Hospital, Cardiac Surgery Ward, 37 patients with advanced coronary arterial disease were asked to participate. The patients were examined prior to the operation, on the day after the operation and two months after the operation and a year after the operation. The ECG recordings were subjected to a numerical procedure of resolution enhancement by a NURSE-ECG program to reveal the tentative changes in the electric potential of the cardiac muscle on its depolarisation. Results of the study have shown that the NURSE ECG method can be applied to monitor changes in the electric activity of the cardiac muscle occurring as a result of CABG operation. One the second day after the operation in the majority of patients (70%) a rapid decrease of the total

  12. A Case Report of Renal Sympathetic Denervation for the Treatment of Polymorphic Ventricular Premature Complexes

    Science.gov (United States)

    Kiuchi, Márcio Galindo; Vitorio, Frederico Puppim; da Silva, Gustavo Ramalho; Paz, Luis Marcelo Rodrigues; Souto, Gladyston Luiz Lima

    2015-01-01

    Abstract Premature ventricular complexes are very common, appearing most frequently in patients with hypertension, obesity, sleep apnea, and structural heart disease. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of ventricular arrhythmias. Recently, Armaganijan et al reported the relevance of sympathetic activation in patients with ventricular arrhythmias and suggested a potential role for catheter-based renal sympathetic denervation in reducing the arrhythmic burden. In this report, we describe a 32-year-old hypertensive male patient presenting with a high incidence of polymorphic premature ventricular complexes on a 24 hour Holter monitor. Beginning 1 year prior, the patient experienced episodes of presyncope, syncope, and tachycardia palpitations. The patient was taking losartan 100 mg/day, which kept his blood pressure (BP) under control, and sotalol 160 mg twice daily. Bisoprolol 10 mg/day was used previously but was not successful for controlling the episodes. The 24 hour Holter performed after the onset of sotalol 160 mg twice daily showed a heart rate ranging between 48 (minimum)–78 (average)–119 (maximum) bpm; 14,286 polymorphic premature ventricular complexes; 3 episodes of nonsustained ventricular tachycardia, the largest composed of 4 beats at a rate of 197 bpm; and 14 isolated atrial ectopic beats. Cardiac magnetic resonance imaging with gadolinium perfusion performed at rest and under pharmacological stress with dipyridamole showed increased left atrial internal volume, preserved systolic global biventricular function, and an absence of infarcted or ischemic areas. The patient underwent bilateral renal sympathetic denervation. The only drug used postprocedure was losartan 25 mg/day. Three months after the patient underwent renal sympathetic denervation, the mean BP value dropped to 132/86 mmHg, the mean systolic/diastolic 24 hour ambulatory BP measurement was reduced to 128/83

  13. (123)I-Meta-iodobenzylguanidine Sympathetic Imaging: Standardization and Application to Neurological Diseases.

    Science.gov (United States)

    Nakajima, Kenichi; Yamada, Masahito

    2016-09-01

    (123)I-meta-iodobenzylguanidine (MIBG) has become widely applied in Japan since its introduction to clinical cardiology and neurology practice in the 1990s. Neurological studies found decreased cardiac uptake of (123)I-MIBG in Lewy-body diseases including Parkinson's disease and dementia with Lewy bodies. Thus, cardiac MIBG uptake is now considered a biomarker of Lewy body diseases. Although scintigraphic images of (123)I-MIBG can be visually interpreted, an average count ratio of heart-to-mediastinum (H/M) has commonly served as a semi-quantitative marker of sympathetic activity. Since H/M ratios significantly vary according to acquisition and processing conditions, quality control should be appropriate, and quantitation should be standardized. The threshold H/M ratio for differentiating Lewy-body disease is 2.0-2.1, and was based on standardized H/M ratios to comparable values of medium-energy collimators. Parkinson's disease can be separated from various types of parkinsonian syndromes using cardiac (123)I-MIBG, whereas activity is decreased on images of Lewy-body diseases using both (123)I-ioflupane for the striatum and (123)I-MIBG. Despite being a simple index, the H/M ratio of (123)I-MIBG uptake is reproducible and can serve as an effective tool to support a diagnosis of Lewy-body diseases in neurological practice. PMID:27689024

  14. 123I-Meta-iodobenzylguanidine Sympathetic Imaging: Standardization and Application to Neurological Diseases

    Science.gov (United States)

    Yamada, Masahito

    2016-01-01

    123I-meta-iodobenzylguanidine (MIBG) has become widely applied in Japan since its introduction to clinical cardiology and neurology practice in the 1990s. Neurological studies found decreased cardiac uptake of 123I-MIBG in Lewy-body diseases including Parkinson's disease and dementia with Lewy bodies. Thus, cardiac MIBG uptake is now considered a biomarker of Lewy body diseases. Although scintigraphic images of 123I-MIBG can be visually interpreted, an average count ratio of heart-to-mediastinum (H/M) has commonly served as a semi-quantitative marker of sympathetic activity. Since H/M ratios significantly vary according to acquisition and processing conditions, quality control should be appropriate, and quantitation should be standardized. The threshold H/M ratio for differentiating Lewy-body disease is 2.0-2.1, and was based on standardized H/M ratios to comparable values of medium-energy collimators. Parkinson's disease can be separated from various types of parkinsonian syndromes using cardiac 123I-MIBG, whereas activity is decreased on images of Lewy-body diseases using both 123I-ioflupane for the striatum and 123I-MIBG. Despite being a simple index, the H/M ratio of 123I-MIBG uptake is reproducible and can serve as an effective tool to support a diagnosis of Lewy-body diseases in neurological practice. PMID:27689024

  15. Effect of nitric oxide on rostral ventrolateral medulla modulating cardiac sympathetic afferent reflex in rats with chronic heart failure%延髓头端腹外侧区一氧化氮对慢性心力衰竭大鼠心交感传入反射的影响

    Institute of Scientific and Technical Information of China (English)

    高兴亚; 郭瑞; 王玮; 张枫; 朱国庆

    2005-01-01

    大变化速率明显降低,左室舒张末压明显增加.②与假手术大鼠相比,慢性心力衰竭大鼠的心交感传入反射显著增强.③延髓头端腹外侧区微量注射MeTC(80 nmol)仅增强假手术大鼠的心交感传入反射,对慢性心力衰竭大鼠的心交感传入反射无显著影响.④延髓头端腹外侧区微量注射SNAP(50 nmol)同时抑制假手术和慢性心力衰竭大鼠的心交感传入反射.⑤心室前壁表面用利多卡因预处理可完全抑制心室前壁表面应用缓激肽所引起的肾交感神经活动增加.结论:延髓头端腹外侧区的一氧化氮抑制正常大鼠和慢性心力衰竭大鼠心室表面应用缓激肽引起的心交感传入反射,慢性心力衰竭大鼠心交感传入反射增强与延髓头端腹外侧区中内源性一氧化氮减少有关.%BACKGROUND: Nitric oxide in the central nervous system is involved in controlling the sympathetic outflow. The authors' recent data show that the reduction of nitric oxide in the rostral ventrolateral medulla (RVLM)enhanced the cardiac sympathetic afferent reflex (CSAR) evoked by stimulating the cardiac sympathetic afferent nerves in rats with chronic heart failure (CHF).OBJECTIVE: To further investigate the effect of nitric oxide in the RVLM on modulating the CSAR evoked by epicardial chemical stimulation in rats with CHF.DESIGN: Randomized controlled experiment.SETTING: Department of Physiology, Nanjing Medical University, and Department of Cellular and Integrative Physiology, University of Nebraska College of Medicine.MATERIALS: This study was carried out in the Department of Physiology, Nanjing Medical University from July 2003 to May 2004. A total of 52male Sprague-Dawley rats weighing 360-420 g were used, and were randomly divided into chronic heart failure group and control group with 23 in each group.METHODS: The rats were carried out either sham surgery or the left coronary artery ligation. Six to eight weeks later, all rats were

  16. Activation of mitochondrial STAT-3 and reduced mitochondria damage during hypothermia treatment for post-cardiac arrest myocardial dysfunction.

    Science.gov (United States)

    Huang, Chien-Hua; Tsai, Min-Shan; Chiang, Chih-Yen; Su, Yu-Jen; Wang, Tzung-Dau; Chang, Wei-Tien; Chen, Huei-Wen; Chen, Wen-Jone

    2015-11-01

    While therapeutic hypothermia improves the outcomes of individuals in cardiac arrest, the hemodynamic responses and mechanisms which underlie hypothermia-induced cardioprotection are not fully understood. Therefore, we investigated the mechanism by which induced hypothermia preserves cardiac function and protects against mitochondrial damage following cardiac arrest. Cardiac arrest was induced in adult male Wistar rats by asphyxiation for 8.5 min. Following resuscitation, the animals were randomly assigned to a hypothermia (32 °C) or normothermia (37 °C) group. Monitoring results showed that cardiac output at the fourth hour after resuscitation was significantly better in rats treated with hypothermia when compared to rats treated with normothermia (P mitochondrial permeability transition pores occurred less frequently in the hypothermic group. While complex I/III activity in the electron transport reaction was damaged after cardiac arrest and resuscitation, the degree of injury was ameliorated by hypothermia treatment (P mitochondrial integrity and electron transport activity.

  17. [Reflex sympathetic dystrophy].

    Science.gov (United States)

    Oliveira, Marta; Manuela, Manuela; Cantinho, Guilhermina

    2011-01-01

    Reflex Sympathetic Dystrophy is rare in pediatrics. It is a complex regional pain syndrome, of unknown etiology, usually post-traumatic, characterized by dysfunctions of the musculoskeletal, vascular and skin systems: severe persistent pain of a limb, sensory and vascular alterations, associated disability and psychosocial dysfunction. The diagnosis is based in high clinical suspection. In children and adolescents there are aspects that are different from the adult ones. Excessive tests may result in worsening of the clinical symptoms. Bone scintigraphy can help. Pain treatment is difficult, not specific. Physical therapies and relaxation technics give some relief. Depression must be treated. This syndrome includes fibromyalgia and complex regional pain syndrome type I. We present a clinical report of an adolescent girl, referred for pain, cold temperature, pallor and functional disability of an inferior limb, all signals disclosed by a minor trauma. She had been diagnosed depression the year before. The bone scintigraphy was a decisive test. The treatment with gabapentin, C vitamin, physiotherapy and pshycotherapy has been effective. PMID:22713207

  18. Effects of renal sympathetic nerve radiofrequency ablation on norepinephrine spillover rate and sympathetic nerve activity in dogs with hypertension%肾交感神经射频消融术对高血压犬去甲肾上腺素溢出率及交感神经活性的影响

    Institute of Scientific and Technical Information of China (English)

    余航; 杨成明; 李慧杰; 曾春雨; 方玉强; 何多芬; 张小群; 温春兰

    2012-01-01

    目的 评价肾交感神经射频消融术(RSD)治疗腹主动脉缩窄型高血压犬的有效性和作用机制.方法 成年健康杂种犬20只,采用腹主动脉缩窄法建立高血压模型.模型建立后,随机分为治疗组(n=10)和对照组(n=10).治疗组犬于建模后1个月行双侧肾交感神经射频消融术.分别于建立模型前和建立模型后1、2、3个月,测定犬前上臂血压、交感神经活性及去甲肾上腺素溢出率并观察其变化趋势.结果 建模后1个月,对照组前上臂收缩压(SBP)、舒张压(DBP)和平均动脉压(MAP)与建模前比较均明显升高(P<0.05),肾交感神经活性冲动明显增强,去甲肾上腺素溢出率水平明显增高(P<0.05).治疗组RSD手术即刻肾交感神经活性明显下降,至消融后2个月略有增高;去甲肾上腺素溢出率水平在建模后1个月显著增高(P<0.05),消融后显著降低并一直持续至实验结束(P<0.05).与对照组比较,治疗组消融后1个月、2个月去甲肾上腺素溢出率水平显著降低(P<0.05).结论 RSD对于高血压犬去甲肾上腺素溢出率及交感神经活性均有明显抑制作用.%Objective To evaluate the validity and explore the mechanism of renal sympathetic denervation (RSD) in the treatment of dogs with hypertension reproduced by constriction of abdominal aorta. Methods The hypertension model was reproduced by constriction of abdominal aorta in 20 adult healthy dogs. These dogs were then randomly divided into the treatment group and control group (10 each). Renal sympathetic nerve radiofrequency ablation was done in treatment group 1 month after modeling. The foreleg blood pressure, sympathetic activity and norepinephrine overflow rate of dogs in two groups were detected before modeling, and 1, 2 and 3 months after modeling, and the trend of the change was also observed. Results One month after modeling, the systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood

  19. Calcium binding to cardiac myocytes protected from proteolytic enzyme activity.

    Science.gov (United States)

    Bailey, L E; Fawzi, A B

    1985-04-17

    Excitation-contraction coupling in cardiac muscle is dependent on extracellular calcium and calcium bound to the surface of the myocardial cell. In this study, we examined the physical characteristics of calcium binding to adult guinea pig ventricular myocytes disaggregated mechanically in oxygenated tissue culture medium containing a proteinase inhibitor (aprotinin), and separated from cellular debris by Cytodex beads. Cells prepared in this manner excluded Trypan blue and showed no evidence of spontaneous contraction or contracture. Scatchard plots of calcium binding determined by continuous flow equilibrium dialysis revealed a high-affinity, low-capacity pool, Ka = 65 X 10(3) M-1 and Bt = 1.3 nmol X mg-1 and a low-affinity, high-capacity pool, Ka = 141 M-1 and Bt = 138 nmol X mg-1. The low-affinity pool was not detectable after lanthanum, trypsin or collagenase treatment or in cells prepared without aprotinin in the isolation medium. Both neuraminidase and phospholipase C reduced Bt of the low-affinity pool by one half, but only neuraminidase affected the affinity constant of this pool. Ka was increased to 516.7 M-1, similar to the apparent affinity constant for calcium binding estimated from dP/dtmax measured at several extracellular calcium concentrations (470 M-1). The results suggest that calcium bound to sarcolemmal phospholipids represents the superficial calcium involved in excitation-contraction coupling in the heart.

  20. Neuroanatomy of cardiac activity-regulating circuitry : A transneuronal retrograde viral labelling study in the rat

    NARCIS (Netherlands)

    TerHorst, GJ; Hautvast, RWM; DeJongste, MJL; Korf, J

    1996-01-01

    The anatomy of cardiac activity-regulating circuitry was studied with retrograde transneuronal viral labelling after pseudorabies virus injections into different parts of the rat heart. Transection of the spinal cord at Th1 was used to reveal selectively the parasympathetic neuronal networks. Virus-

  1. ARRHYTHMOGENIC CALMODULIN MUTATIONS AFFECT THE ACTIVATION AND TERMINATION OF CARDIAC RYANODINE RECEPTOR MEDIATED CA2+ RELEASE

    DEFF Research Database (Denmark)

    Søndergaard, Mads Toft; Chazin, Walter J.; Chen, Wayne S.R.;

    We recently identified the first two human missense mutations in a calmodulin (CaM) gene (CALM1) and linked these to catecholaminergic polymorphic ventricular tachycardia (CPVT) and sudden cardiac death in young individuals1. More CaM mutations have since been identified in CALM1 and also...... in the other two CaM genes (CALM2 and CALM3). All CaM mutations are associated with severe ventricular arrhythmias. CaM regulates several key proteins governing cardiac excitation-contraction coupling (ECC), including the cardiac ryanodine receptor (RyR2) Ca2+ release channel. RyR2 mutations also dominantly...... cause CPVT, where the mutations increase the channel sensitivity to activation and enhance the propensity for pro-arrhythmogenic spontaneous Ca2+ release. Here we investigated the effect of CPVT-linked CaM mutations (N53I and N97S) and two CaM mutations identified in individuals with early onset severe...

  2. In-Hospital Cardiac Arrest: An Update on Pulseless Electrical Activity and Asystole.

    Science.gov (United States)

    Attin, Mina; Tucker, Rebecca G; Carey, Mary G

    2016-09-01

    Nonshockable rhythms, including pulseless electrical activity (PEA) and asystole, precede more than 70% of in-hospital cardiac arrests (I-HCA). Compared with shockable rhythms (ventricular fibrillation and ventricular tachycardia), nonshockable rhythms have higher mortality and morbidity. Therefore, investigating the underlying mechanisms of these arrhythmias to improve the quality of care and outcome for patients who suffer cardiac arrest is a priority. As the first responders to I-HCA, nurses must have the proper knowledge and training to provide timely and efficient cardiopulmonary resuscitation therapy. This article provides an overview of nonshockable cardiac arrhythmias preceding I-HCA as a means of addressing the gap between science and clinical practice. PMID:27484665

  3. Primary cardiac diffuse large B-cell lymphoma with activated B-cell-like phenotype

    Directory of Open Access Journals (Sweden)

    Vijaya Gadage

    2011-01-01

    Full Text Available Primary cardiac lymphoma (PCL is a rare and fatal disorder. It may often mimic other common cardiac tumors like cardiac myxoma because of similarities in the clinical presentation. We report a case of PCL of diffuse large B-cell type, in a 38-year-old, immunocompetent male who presented with superior vena cava syndrome that was excised as a myxoma. Histology revealed a large cell population diffusely and strongly expressing CD45, CD20, MUM1/IRF4 and FOXP1 hinting at an activated B-cell (ABC-like phenotype. After four cycles of Rituximab with CHOP (cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisolone the tumor regressed completely but the patient had a relapse and subsequently succumbed to the disease confirming the aggressive nature. The aggressive behavior of PCL may be possibly linked to its ABC-like origin.

  4. Murine cardiac images obtained with focusing pinhole SPECT are barely influenced by extra-cardiac activity

    Science.gov (United States)

    Branderhorst, Woutjan; van der Have, Frans; Vastenhouw, Brendan; Viergever, Max A.; Beekman, Freek J.

    2012-02-01

    Ultra-high-resolution SPECT images can be obtained with focused multipinhole collimators. Here we investigate the influence of unwanted high tracer uptake outside the scan volume on reconstructed tracer distributions inside the scan volume, for 99mTc-tetrofosmin myocardial perfusion scanning in mice. Simulated projections of a digital mouse phantom (MOBY) in a focusing multipinhole SPECT system (U-SPECT-II, MILabs, The Netherlands) were generated. With this system differently sized user-defined scan volumes can be selected, by translating the animal in 3D through the focusing collimators. Scan volume selections were set to (i) a minimal volume containing just the heart, acquired without translating the animal during scanning, (ii) a slightly larger scan volume as is typically applied for the heart, requiring only small XYZ translations during scanning, (iii) same as (ii), but extended further transaxially, and (iv) same as (ii), but extended transaxially to cover the full thorax width (gold standard). Despite an overall negative bias that is significant for the minimal scan volume, all selected volumes resulted in visually similar images. Quantitative differences in the reconstructed myocardium between gold standard and the results from the smaller scan volume selections were small; the 17 standardized myocardial segments of a bull's eye plot, normalized to the myocardial mean of the gold standard, deviated on average 6.0%, 2.5% and 1.9% for respectively the minimal, the typical and the extended scan volume, while maximum absolute deviations were respectively 18.6%, 9.0% and 5.2%. Averaged over ten low-count noisy simulations, the mean absolute deviations were respectively 7.9%, 3.2% and 1.9%. In low-count noisy simulations, the mean and maximum absolute deviations for the minimal scan volume could be reduced to respectively 4.2% and 12.5% by performing a short survey scan of the exterior activity and focusing the remaining scan time at the organ of interest. We

  5. Extra cardiac activity detected on myocardial perfusion scintigraphy after intra-arterial injection of 99mTc-MIBI

    DEFF Research Database (Denmark)

    Afzelius, Pia; Henriksen, Jens H

    2008-01-01

    , prolongation of the study and interference of the extra cardiac activity with the cardiac image reconstructions. Whole-body scintigraphy disclosed an arterial flow distribution of activity to skeletal muscles in left shoulder and upper limb. CONCLUSION: Accidentally injected radiotracer retrogradely......PURPOSE: We present an unusual case of extra cardiac activity of 99mTc-MIBI in the left part of thorax and left upper extremity in a patient admitted for myocardial perfusion scintigraphy. METHODS: A standard 2-day protocol of 99mTc-MIBI perfusion scintigraphies starting day 1 with stress...... (dipyridamol) imaging and followed by rest imaging day 2 was performed. RESULTS: On day 2, when rest perfusion scintigraphy was carried out, extra cardiac activity was present in the left part of thorax and in the left upper extremity resulting in reduced accumulation of 99mTc-MIBI in cardiac tissue...

  6. Objectively measured daily physical activity related to cardiac size in young children

    DEFF Research Database (Denmark)

    Dencker, M; Thorsson, O; Karlsson, M K;

    2009-01-01

    ), aged 8-11 years, from a population-based cohort. Left ventricular end-diastolic diameter (LVDD) and left atrial end-systolic diameter (LA) were measured with echocardiography and indexed for body surface area (BSA). Physical activity was assessed by accelerometry, and the duration of vigorous physical...... activity per day (VPA) was calculated. Acceptable accelerometer and echocardiography measurements were obtained in 228 children (boys=127, girls=101). Univariate correlations between VPA and LVDD were indexed for BSA in boys (r=0.27, P... that independent factors for LVDD, indexed for BSA for boys, were age and VPA. LA indexed for BSA was not related to physical activity variables in either gender. No clear relationship exists between cardiac size and daily physical activity in children aged 8-11 years. This suggests that significant cardiac...

  7. The paradox of systemic vasodilatation and sympathetic nervous stimulation in space

    DEFF Research Database (Denmark)

    Norsk, Peter; Christensen, Niels Juel

    2009-01-01

    Cardiac output is increased by some 18% by weightlessness during the initial week of spaceflight compared to upright standing or sitting on the ground and more so during the initial days of flight than at the end. In addition, mean 24-h diastolic, but not systolic pressure, is significantly...... decreased by 5mmHg. This is in accordance with observations that very acute weightlessness during parabolic airplane flights and a week of weightlessness in space leads to a decrease in systemic vascular resistance. That the arterial resistance vessels are dilated in space is in contrast to the augmented...... sympathetic nervous activity and decreased urine production, which have consistently been observed in astronauts in space. These contrasting observations require further investigation....

  8. Activation of GATA4 gene expression at the early stage of cardiac specification

    Directory of Open Access Journals (Sweden)

    Ayse eYilbas

    2014-03-01

    Full Text Available Currently, there are no effective treatments to directly repair damaged heart tissue after cardiac injury since existing therapies focus on rescuing or preserving reversibly damaged tissue. Cell-based therapies using cardiomyocytes generated from stem cells present a promising therapeutic approach to directly replace damaged myocardium with new healthy tissue. However, the molecular mechanisms underlying the commitment of stem cells into cardiomyocytes are not fully understood and will be critical to guide this new technology into the clinic. Since GATA4 is a critical regulator of cardiac differentiation, we examined the molecular basis underlying the early activation of GATA4 gene expression during cardiac differentiation of pluripotent stem cells. Our studies demonstrate the direct involvement of histone acetylation and transcriptional coactivator p300 in the regulation of GATA4 gene expression. More importantly, we show that histone acetyltransferase (HAT activity is important for GATA4 gene expression with the use of curcumin, a HAT inhibitor. In addition, the widely used histone deacetylase inhibitor valproic acid enhances both histone acetylation and cardiac specification.

  9. Activation of GATA4 gene expression at the early stage of cardiac specification

    Science.gov (United States)

    Yilbas, Ayse; Hamilton, Alison; Wang, Yingjian; Mach, Hymn; Lacroix, Natascha; Davis, Darryl; Chen, Jihong; LI, Qiao

    2014-03-01

    Currently, there are no effective treatments to directly repair damaged heart tissue after cardiac injury since existing therapies focus on rescuing or preserving reversibly damaged tissue. Cell-based therapies using cardiomyocytes generated from stem cells present a promising therapeutic approach to directly replace damaged myocardium with new healthy tissue. However, the molecular mechanisms underlying the commitment of stem cells into cardiomyocytes are not fully understood and will be critical to guide this new technology into the clinic. Since GATA4 is a critical regulator of cardiac differentiation, we examined the molecular basis underlying the early activation of GATA4 gene expression during cardiac differentiation of pluripotent stem cells. Our studies demonstrate the direct involvement of histone acetylation and transcriptional coactivator p300 in the regulation of GATA4 gene expression. More importantly, we show that histone acetyltransferase (HAT) activity is important for GATA4 gene expression with the use of curcumin, a HAT inhibitor. In addition, the widely used histone deacetylase inhibitor valproic acid enhances both histone acetylation and cardiac specification.

  10. Echocardiography integrated ACLS protocol versus conventional cardiopulmonary resuscitation in patients with pulseless electrical activity cardiac arrest

    Institute of Scientific and Technical Information of China (English)

    Mojtaba Chardoli; Farhad Heidari; Helaleh Rabiee; Mahdi Sharif-Alhoseini; Hamid Shokoohi; Vafa Rahimi-Movaghar

    2012-01-01

    Objective: To examine the utility of bedside echocardiography in detecting the reversible causes of pulseless electrical activity (PEA) cardiac arrest and predicting the resuscitation outcomes.Methods: In this prospective interventional study,patients presenting with PEA cardiac arrest were randomized into two groups.In Group A,ultrasound trained emergency physicians performed echocardiography evaluating cardiac activity,right ventricle dilation,left ventricle function,pericardial effusion/tamponade and ⅣC size along with the advanced cardiac life support (ACLS) protocol.Patients in Group B solely underwent ACLS protocol without applying echocardiography.The presence or absence of mechanical ventricular activity (MVA) and evidences of PEA reversible causes were recorded.The return of spontaneous circulation (ROSC) and death were evaluated in both groups.Results: One hundred patients with the mean age of (58±6.1) years were enrolled in this study.Fifty patients (Group A) had echocardiography detected in parallel with cardiopulmonary resuscitation (CPR).Among them,7 patients (14%) had pericardial effusion,11 (22%) had hypovolemia,and 39 (78%) were revealed the presence of MVA.In the pseudo PEA subgroup (presence of MVA),43% had ROSC (positive predictive value) and in the true PEA subgroup with cardiac standstill (absence of MVA),there was no recorded ROSC (negative predictive value).Among patients in Group B,no reversible etiology was detected.There was no significant difference in resuscitation results between Groups A and B observed (P=0.52).Conclusion: Bedside echocardiography can identify some reversible causes of PEA.However,there are no significant changes in survival outcome between the echo group and those with traditional CPR.

  11. Characteristics of renal sympathetic nerve single units in rabbits with angiotensin-induced hypertension.

    Science.gov (United States)

    Burke, Sandra L; Lukoshkova, Elena V; Head, Geoffrey A

    2016-01-01

    We examined the effect of chronic angiotensin (Ang II)-induced hypertension on activity of postganglionic renal sympathetic units to determine whether altered whole renal nerve activity is due to recruitment or changes in firing frequency. Rabbits were treated with a low (20 ng kg(-1) min(-1), 8 weeks) or high dose (50 ng kg(-1) min(-1), 4 weeks) of Ang II before the experiment under chloralose-urethane anaesthesia. Spontaneously active units were detected from multiunit recordings using an algorithm that separated units by action potential shape using templates that matched spikes within a prescribed standard deviation. Multiunit sympathetic nerve activity was 40% higher in rabbits treated with low-dose Ang II than in sham (P = 0.012) but not different in high-dose Ang II. Resting firing frequency was similar in sham rabbits (1.00 ± 0.09 spikes s(-1), n = 144) and in those treated with high-dose Ang II (1.10 ± 0.08 spikes s(-1), n = 112) but was lower with low-dose Ang II (0.65 ± 0.08 spikes s(-1), n = 149, P < 0.05). Unit firing rhythmicity was linked to the cardiac cycle and was similar in sham and low-dose Ang II groups but 29-32% lower in rabbits treated with high-dose Ang II (P < 0.001). Cardiac linkage followed a similar pattern during hypoxia. All units showed baroreceptor dependency. Baroreflex gain and range were reduced and curves shifted to the right in Ang II groups. Firing frequency during hypoxia increased by +39% in low-dose Ang II and +82% in shams, but the greatest increase was in the high-dose Ang II group (+103%, P(dose) = 0.001). Responses to hypercapnia were similar in all groups. Increases in sympathetic outflow in hypertension caused by low-dose chronic Ang II administration are due to recruitment of neurons, but high-dose Ang II increases firing frequency in response to chemoreceptor stimuli independently of the arterial baroreceptors. PMID:26467849

  12. Cardiac iodine-123 metaiodobenzylguanidine uptake in animals with diabetes mellitus and/or hypertension

    International Nuclear Information System (INIS)

    The aim of the present study was to evaluate the use of the noradrenaline analogue iodine-123 metaiodobenzylguanidine ([123I]MIBG) for the assessment of cardiac sympathetic activity in the presence of diabetes mellitus and/or hypertension in animal models. One model used Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) rendered diabetic at 12 weeks of age by an intravenous injection of streptozotocin (STZ). The other model used lean and obese Zucker rats. In all groups basic haemodynamic values were established and animals received an intravenous injection of 50 μCi [123I]MIBG. Initial myocardial uptake and washout rates of [123I]MIBG were measured scintigraphically during 4 h. After sacrifice, plasma noradrenaline and left cardiac ventricular β-adrenoceptor density was determined. The diabetic state, both in STZ-treated rats (direct induction) and in obese Zucker rats (genetic induction), appeared to induce a lower cardiac density of β-adrenoceptors, indicative of increased sympathetic activity. Cardiac [123I]MIBG then showed increased washouts, thereby confirming enhanced noradrenergic activity. This parallism of results led to the conclusion that [123I]MIBG wash-out measurements could provide an excellent tool to assess cardiac sympathetic activity noninvasively. However, in hypertension (WKY vs SHR), both parameters failed to show parallelism: no changes in β-adrenoceptor density were found, whereas [123I]MIBG wash-out rate was increased. Thus, either [123I]MIBG washout or β-adrenoceptor density may not be a reliable parameter under all circumstances to detect changes in the release of noradrenaline. (orig./MG)

  13. Cardiac iodine-123 metaiodobenzylguanidine uptake in animals with diabetes mellitus and/or hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, E.A. [Dept. of Nuclear Medicine, Academic Medical Center, Univ. of Amsterdam (Netherlands)]|[Dept. of Pharmacotherapy, Academic Medical Center, Univ. of Amsterdam (Netherlands); Kam, K.L. [Dept. of Pharmacotherapy, Academic Medical Center, Univ. of Amsterdam (Netherlands); Somsen, G.A. [Dept. of Cardiology, Academic Medical Center, Univ. of Amsterdam (Netherlands); Boer, G.J. [Dept. of Nuclear Medicine, Academic Medical Center, Univ. of Amsterdam (Netherlands); Bruin, K. de [Dept. of Nuclear Medicine, Academic Medical Center, Univ. of Amsterdam (Netherlands); Batink, H.D. [Dept. of Pharmacotherapy, Academic Medical Center, Univ. of Amsterdam (Netherlands); Pfaffendorf, M. [Dept. of Pharmacotherapy, Academic Medical Center, Univ. of Amsterdam (Netherlands); Royen, E.A. van [Dept. of Nuclear Medicine, Academic Medical Center, Univ. of Amsterdam (Netherlands); Zwieten, P.A. van [Dept. of Pharmacotherapy, Academic Medical Center, Univ. of Amsterdam (Netherlands)]|[Dept. of Cardiology, Academic Medical Center, Univ. of Amsterdam (Netherlands)

    1996-08-01

    The aim of the present study was to evaluate the use of the noradrenaline analogue iodine-123 metaiodobenzylguanidine ([{sup 123}I]MIBG) for the assessment of cardiac sympathetic activity in the presence of diabetes mellitus and/or hypertension in animal models. One model used Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) rendered diabetic at 12 weeks of age by an intravenous injection of streptozotocin (STZ). The other model used lean and obese Zucker rats. In all groups basic haemodynamic values were established and animals received an intravenous injection of 50 {mu}Ci [{sup 123}I]MIBG. Initial myocardial uptake and washout rates of [{sup 123}I]MIBG were measured scintigraphically during 4 h. After sacrifice, plasma noradrenaline and left cardiac ventricular {beta}-adrenoceptor density was determined. The diabetic state, both in STZ-treated rats (direct induction) and in obese Zucker rats (genetic induction), appeared to induce a lower cardiac density of {beta}-adrenoceptors, indicative of increased sympathetic activity. Cardiac [{sup 123}I]MIBG then showed increased washouts, thereby confirming enhanced noradrenergic activity. This parallism of results led to the conclusion that [{sup 123}I]MIBG wash-out measurements could provide an excellent tool to assess cardiac sympathetic activity noninvasively. However, in hypertension (WKY vs SHR), both parameters failed to show parallelism: no changes in {beta}-adrenoceptor density were found, whereas [{sup 123}I]MIBG wash-out rate was increased. Thus, either [{sup 123}I]MIBG washout or {beta}-adrenoceptor density may not be a reliable parameter under all circumstances to detect changes in the release of noradrenaline. (orig./MG)

  14. PATIENTS OVERCOME ANXIETY AND ARE ENCOURAGED TO BE PHYSICAL ACTIVE THROUGH EXERCISE-BASED CARDIAC REHABILITATION

    DEFF Research Database (Denmark)

    Simonÿ, Charlotte; Dreyer, Pia; Pedersen, Birthe D.;

    other to begin exercising; and growing confidence in the heart, whereby the patients overcome anxiety and dare to be physically active. Conclusions. Exercise-based cardiac rehabilitation provides a comfort-giving setting that offers peer support and a positive physical perception leading to confidence...... interviews were performed 1-2 months later. A phenomenological hermeneutic interpretation was conducted, comprising three methodological steps: naïve reading, structural analysis and comprehensive interpretation. Results. The preliminary findings are that although physically and especially mentally...... into that the heart endures physical activity. In addition to serving as physical guidance, exercise-based cardiac rehabilitation offers valuable mental support. The patients find help to overcome an initial anxiety and move forward towards a physically active life featuring a feeling of improved health and new...

  15. Reevaluation of the Role of the Sympathetic Nervous System in Cutaneous Vasodilation during Dorsal Spinal Cord Stimulation: Are Multiple Mechanisms Active?

    Science.gov (United States)

    Croom, J E; Foreman, R D; Chandler, M J; Barron, K W

    1998-04-01

    Objective. In addition to treatment of refractory chronic pain in patients with peripheral vascular disease, dorsal spinal cord stimulation (DCS) increases cutaneous blood flow to the extremities and may have a limb-saving effect. The purpose of this study was to examine the role of the sympathetic nervous system in the cutaneous vasodilation due to DCS. Methods. Male Sprague-Dawley rats were anesthetized with pentobarbital (60 mg/kg, i.p.). A unipolar ball electrode was placed on the left side of the exposed spinal cord at approximately the L1-L2 level. Blood flow was concurrently recorded from both hindpaw foot pads with laser Doppler flowmeters. Blood flow responses were assessed during 1 min of DCS (0.6 mA at 50 Hz, 0.2 msec pulse duration) at 10 min intervals. To determine the contribution of the sympathetic nervous system in the blood flow response to DCS, the role of ganglionic transmission, alpha-adrenergic receptors, beta-adrenergic receptors, and adrenal catecholamine secretion were investigated using adrenergic receptor antagonists. Results. Hexamethonium (10 mg/kg, i.v.), an autonomic ganglionic receptor antagonist, did not attenuate the cutaneous vasodilation during DCS. Phentolamine (3 mg/kg, i.v.), a nonselective alpha-adrenergic receptor antagonist, also did not attenuate the DCS-induced increase in peripheral cutaneous blood flow. On the other hand, prazosin (0.1 mg/kg, i.v.), a selective alpha-1-adrenergic receptor antagonist, attenuated the DCS response but this may, at least, be partly due to a vehicle effect. Propranolol (5 mg/kg, i.v.), a nonselective beta-adrenergic receptor antagonist, attenuated the DCS response while adrenal demedullation did not. Conclusion. Overall, our results show that DCS-induced vasodilation can occur through mechanisms that are independent of sympathetic outflow. PMID:22150941

  16. The NADPH Oxidase NOX4 Drives Cardiac Differentiation: Role in Regulating Cardiac Transcription Factors and MAP Kinase Activation

    OpenAIRE

    Li, Jian; Stouffs, Michael; Serrander, Lena; Banfi, Botond; Bettiol, Esther; Charnay, Yves; Steger, Klaus; Krause, Karl-Heinz; Jaconi, Marisa E

    2006-01-01

    Reactive oxygen species (ROS) generated by the NOX family of NADPH oxidases have been described to act as second messengers regulating cell growth and differentiation. However, such a function has hitherto not been convincingly demonstrated. We investigated the role of NOX-derived ROS in cardiac differentiation using mouse embryonic stem cells. ROS scavengers prevented the appearance of spontaneously beating cardiac cells within embryoid bodies. Down-regulation of NOX4, the major NOX isoform ...

  17. Plasma volume substitution does not inhibit plasma noradrenaline and muscle nerve sympathetic responses to insulin-induced hypoglycaemia in healthy humans

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Berne, C; Fagius, J;

    1989-01-01

    Microelectrode recordings of muscle nerve sympathetic activity and measurements of venous plasma noradrenaline have indicated increased sympathetic outflow during acute hypoglycaemia. Plasma volume reduction during hypoglycaemia, as evidenced by increasing peripheral venous haematocrit might...

  18. Cardiac myosin light chain is phosphorylated by Ca2+/calmodulin-dependent and -independent kinase activities.

    Science.gov (United States)

    Chang, Audrey N; Mahajan, Pravin; Knapp, Stefan; Barton, Hannah; Sweeney, H Lee; Kamm, Kristine E; Stull, James T

    2016-07-01

    The well-known, muscle-specific smooth muscle myosin light chain kinase (MLCK) (smMLCK) and skeletal muscle MLCK (skMLCK) are dedicated protein kinases regulated by an autoregulatory segment C terminus of the catalytic core that blocks myosin regulatory light chain (RLC) binding and phosphorylation in the absence of Ca(2+)/calmodulin (CaM). Although it is known that a more recently discovered cardiac MLCK (cMLCK) is necessary for normal RLC phosphorylation in vivo and physiological cardiac performance, information on cMLCK biochemical properties are limited. We find that a fourth uncharacterized MLCK, MLCK4, is also expressed in cardiac muscle with high catalytic domain sequence similarity with other MLCKs but lacking an autoinhibitory segment. Its crystal structure shows the catalytic domain in its active conformation with a short C-terminal "pseudoregulatory helix" that cannot inhibit catalysis as a result of missing linker regions. MLCK4 has only Ca(2+)/CaM-independent activity with comparable Vmax and Km values for different RLCs. In contrast, the Vmax value of cMLCK is orders of magnitude lower than those of the other three MLCK family members, whereas its Km (RLC and ATP) and KCaM values are similar. In contrast to smMLCK and skMLCK, which lack activity in the absence of Ca(2+)/CaM, cMLCK has constitutive activity that is stimulated by Ca(2+)/CaM. Potential contributions of autoregulatory segment to cMLCK activity were analyzed with chimeras of skMLCK and cMLCK. The constitutive, low activity of cMLCK appears to be intrinsic to its catalytic core structure rather than an autoinhibitory segment. Thus, RLC phosphorylation in cardiac muscle may be regulated by two different protein kinases with distinct biochemical regulatory properties. PMID:27325775

  19. Cardiac Iodine-123-Meta-Iodo-Benzylguanidine Uptake in Carotid Sinus Hypersensitivity.

    Directory of Open Access Journals (Sweden)

    Maw Pin Tan

    Full Text Available Carotid sinus syndrome is the association of carotid sinus hypersensitivity with syncope, unexplained falls and drop attacks in generally older people. We evaluated cardiac sympathetic innervation in this disorder in individuals with carotid sinus syndrome, asymptomatic carotid sinus hypersensitivity and controls without carotid sinus hypersensitivity.Consecutive patients diagnosed with carotid sinus syndrome at a specialist falls and syncope unit were recruited. Asymptomatic carotid sinus hypersensitivity and non-carotid sinus hypersensitivity control participants recruited from a community-dwelling cohort. Cardiac sympathetic innervation was determined using Iodine-123-metaiodobenzylguanidine (123-I-MIBG scanning. Heart to mediastinal uptake ratio (H:M were determined for early and late uptake on planar scintigraphy at 20 minutes and 3 hours following intravenous injection of 123-I-MIBG.Forty-two subjects: carotid sinus syndrome (n = 21, asymptomatic carotid sinus hypersensitivity (n = 12 and no carotid sinus hypersensitivity (n = 9 were included. Compared to the non- carotid sinus hypersensitivity control group, the carotid sinus syndrome group had significantly higher early H:M (estimated mean difference, B = 0.40; 95% confidence interval, CI = 0.13 to 0.67, p = 0.005 and late H:M (B = 0.32; 95%CI = 0.03 to 0.62, p = 0.032. There was, however, no significant difference in early H:M (p = 0.326 or late H:M (p = 0.351 between the asymptomatic carotid sinus hypersensitivity group and non- carotid sinus hypersensitivity controls.Cardiac sympathetic neuronal activity is increased relative to age-matched controls in individuals with carotid sinus syndrome but not those with asymptomatic carotid sinus hypersensitivity. Blood pressure and heart rate measurements alone may therefore represent an over simplification in the assessment for carotid sinus syndrome and the relative increase in cardiac sympathetic innervation provides additional clues to

  20. A cardiac electrical activity model based on a cellular automata system in comparison with neural network model.

    Science.gov (United States)

    Khan, Muhammad Sadiq Ali; Yousuf, Sidrah

    2016-03-01

    Cardiac Electrical Activity is commonly distributed into three dimensions of Cardiac Tissue (Myocardium) and evolves with duration of time. The indicator of heart diseases can occur randomly at any time of a day. Heart rate, conduction and each electrical activity during cardiac cycle should be monitor non-invasively for the assessment of "Action Potential" (regular) and "Arrhythmia" (irregular) rhythms. Many heart diseases can easily be examined through Automata model like Cellular Automata concepts. This paper deals with the different states of cardiac rhythms using cellular automata with the comparison of neural network also provides fast and highly effective stimulation for the contraction of cardiac muscles on the Atria in the result of genesis of electrical spark or wave. The specific formulated model named as "States of automaton Proposed Model for CEA (Cardiac Electrical Activity)" by using Cellular Automata Methodology is commonly shows the three states of cardiac tissues conduction phenomena (i) Resting (Relax and Excitable state), (ii) ARP (Excited but Absolutely refractory Phase i.e. Excited but not able to excite neighboring cells) (iii) RRP (Excited but Relatively Refractory Phase i.e. Excited and able to excite neighboring cells). The result indicates most efficient modeling with few burden of computation and it is Action Potential during the pumping of blood in cardiac cycle. PMID:27087101

  1. Acute cold exposure-induced down-regulation of CIDEA, cell death-inducing DNA fragmentation factor-alpha-like effector A, in rat interscapular brown adipose tissue by sympathetically activated beta3-adrenoreceptors.

    Science.gov (United States)

    Shimizu, Takahiro; Yokotani, Kunihiko

    2009-09-18

    The thermogenic activity of brown adipose tissue (BAT) largely depends on the mitochondrial uncoupling protein 1 (UCP1), which is up-regulated by environmental alterations such as cold. Recently, CIDEA (cell death-inducing DNA fragmentation factor-alpha-like effector A) has also been shown to be expressed at high levels in the mitochondria of BAT. Here we examined the effect of cold on the mRNA and protein levels of CIDEA in interscapular BAT of conscious rats with regard to the sympathetic nervous system. Cold exposure (4 degrees C for 3h) elevated the plasma norepinephrine level and increased norepinephrine turnover in BAT. Cold exposure resulted in down-regulation of the mRNA and protein levels of CIDEA in BAT, accompanied by up-regulation of mRNA and protein levels of UCP1. The cold exposure-induced changes of CIDEA and UCP1 were attenuated by intraperitoneal pretreatment with propranolol (a non-selective beta-adrenoreceptor antagonist) (2mg/animal) or SR59230A (a selective beta(3)-adrenoreceptor antagonist) (2mg/animal), respectively. These results suggest that acute cold exposure resulted in down-regulation of CIDEA in interscapular BAT by sympathetically activated beta(3)-adrenoreceptor-mediated mechanisms in rats.

  2. A coarse-grained model to study calcium activation of the cardiac thin filament

    Science.gov (United States)

    Zhang, Jing; Schwartz, Steven

    2015-03-01

    Familial hypertrophic cardiomyopathy (FHC) is one of the most common heart disease caused by genetic mutations. Cardiac muscle contraction and relaxation involve regulation of crossbridge binding to the cardiac thin filament, which regulates actomyosin interactions through calcium-dependent alterations in the dynamics of cardiac troponin (cTn) and tropomyosin (Tm). An atomistic model of cTn complex interacting with Tm has been studied by our group. A more realistic model requires the inclusion of the dynamics of actin filament, which is almost 6 times larger than cTn and Tm in terms of atom numbers, and extensive sampling of the model becomes very resource-demanding. By using physics-based protein united-residue force field, we introduce a coarse-grained model to study the calcium activation of the thin filament resulting from cTn's allosteric regulation of Tm dynamics on actin. The time scale is much longer than that of all-atom molecular dynamics simulation because of the reduction of the degrees of freedom. The coarse-grained model is a good template for studying cardiac thin filament mutations that cause FHC, and reduces the cost of computational resources.

  3. False Alarm Reduction in BSN-Based Cardiac Monitoring Using Signal Quality and Activity Type Information

    Directory of Open Access Journals (Sweden)

    Tanatorn Tanantong

    2015-02-01

    Full Text Available False alarms in cardiac monitoring affect the quality of medical care, impacting on both patients and healthcare providers. In continuous cardiac monitoring using wireless Body Sensor Networks (BSNs, the quality of ECG signals can be deteriorated owing to several factors, e.g., noises, low battery power, and network transmission problems, often resulting in high false alarm rates. In addition, body movements occurring from activities of daily living (ADLs can also create false alarms. This paper presents a two-phase framework for false arrhythmia alarm reduction in continuous cardiac monitoring, using signals from an ECG sensor and a 3D accelerometer. In the first phase, classification models constructed using machine learning algorithms are used for labeling input signals. ECG signals are labeled with heartbeat types and signal quality levels, while 3D acceleration signals are labeled with ADL types. In the second phase, a rule-based expert system is used for combining classification results in order to determine whether arrhythmia alarms should be accepted or suppressed. The proposed framework was validated on datasets acquired using BSNs and the MIT-BIH arrhythmia database. For the BSN dataset, acceleration and ECG signals were collected from 10 young and 10 elderly subjects while they were performing ADLs. The framework reduced the false alarm rate from 9.58% to 1.43% in our experimental study, showing that it can potentially assist physicians in diagnosing a vast amount of data acquired from wireless sensors and enhance the performance of continuous cardiac monitoring.

  4. Effects of renal sympathetic denervation on cardiac remodeling following myocardial infarction in rats%去肾交感神经术对大鼠急性心肌梗死后心室重构的影响

    Institute of Scientific and Technical Information of China (English)

    刘夙璇; 王国坤; 丁雪燕; 董斐斐; 安丽娜; 赵仙先; 秦永文

    2014-01-01

    目的 对急性心肌梗死(myocardial infarction,MI)大鼠进行双侧肾交感神经切除,探讨去肾交感神经术(renal sympathetic denervation,RDN)能否缓解MI后心室重构并进行可能的机制探讨.方法 结扎大鼠左冠状动脉前降支构建MI模型,实验分组为:MI组(n=10)、MI+ RDN组(MI建模1周后进行RDN,n=10)和假手术组(n=10).MI建模4周后对各组大鼠进行超声心动图检查测定心室重构程度和左心功能,对梗死边缘区心肌进行Masson染色观察心肌纤维化程度,免疫组化检测Ⅰ型胶原、Ⅲ型胶原和转化生长因子β1 (transforming growth factor β1,TGF-β1)的表达.结果 与MI组相比,MI+ RDN组的左室射血分数(ejection fraction,EF)和短轴缩短率(fractional shortening,FS)升高,左室收缩末期内径(left ventricular internal dimensions at end systole,LVIDS)和左室舒张末期内径(left ventricular internal dimensions at end diastole, LVIDD)减少(P均<0.05).心肌Masson染色结果显示,MI+ RDN组大鼠梗死边缘区的心肌纤维化程度较MI组减轻.免疫组化检测显示,与MI组相比,MI+RDN组大鼠梗死边缘区的Ⅰ型胶原、Ⅲ型胶原和TGF-β1表达减少(P均<o.05).结论 RDN可以改善Mt大鼠心室重构,提高左心收缩功能,其机制可能与局部下调心肌TGF-β1表达进而减少Ⅰ型胶原和Ⅲ型胶原沉积有关.

  5. Activation of cardiac chloride conductance by the tyrosine kinase inhibitor, genistein.

    OpenAIRE

    Shuba, L. M.; Asai, T.; Pelzer, S.; McDonald, T. F.

    1996-01-01

    1. Genistein (GST), an inhibitor of protein tyrosine kinase (PTK), Na3VO4 (VO4), an inhibitor of phosphotyrosine phosphatase (PTPase), and forskolin (FSK), an activator of the cyclic AMP-dependent, cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel, were applied to guinea-pig ventricular myocytes to probe for a possible role of tyrosine phosphorylation in the regulation of cardiac Cl- channels. 2. Myocytes in the standard whole-cell configuration were pulsed to various pot...

  6. Correlations between the Signal Complexity of Cerebral and Cardiac Electrical Activity: A Multiscale Entropy Analysis

    OpenAIRE

    Pei-Feng Lin; Men-Tzung Lo; Jenho Tsao; Yi-Chung Chang; Chen Lin; Yi-Lwun Ho

    2014-01-01

    The heart begins to beat before the brain is formed. Whether conventional hierarchical central commands sent by the brain to the heart alone explain all the interplay between these two organs should be reconsidered. Here, we demonstrate correlations between the signal complexity of brain and cardiac activity. Eighty-seven geriatric outpatients with healthy hearts and varied cognitive abilities each provided a 24-hour electrocardiography (ECG) and a 19-channel eye-closed routine electroencepha...

  7. Crosstalk between mitogen-activated protein kinases and mitochondria in cardiac diseases: therapeutic perspectives

    OpenAIRE

    Javadov, Sabzali; Jang, Sehwan; Agostini, Bryan

    2014-01-01

    Cardiovascular diseases cause more mortality and morbidity worldwide than any other diseases. Although many intracellular signaling pathways influence cardiac physiology and pathology, the mitogen-activated protein kinase (MAPK) family has garnered significant attention because of its vast implications in signaling and cross-talk with other signaling networks. The extensively studied MAPKs ERK1/2, p38, JNK, and ERK5, demonstrate unique intracellular signaling mechanisms, responding to a myria...

  8. Cardiac dysfunction and hypothalamic activation during a social crowding stressor in prairie voles

    OpenAIRE

    Grippo, Angela J.; Sgoifo, Andrea; Mastorci, Francesca; McNeal, Neal; Trahanas, Diane M.

    2010-01-01

    Cardiac dysfunction and hypothalamic activation during a social crowding stressor in prairie voles. – Negative social interactions produce several detrimental consequences in humans and non-human animals; and conversely, positive social interactions may have stress-buffering effects on both behavior and physiology. However, the mechanisms underlying specific stressor-responsiveness in the context of the social environment are not well understood. The present study investigated the integration...

  9. Role of sympathetic nervous system and neuropeptides in obesity hypertension

    Directory of Open Access Journals (Sweden)

    Hall J.E.

    2000-01-01

    Full Text Available Obesity is the most common cause of human essential hypertension in most industrialized countries. Although the precise mechanisms of obesity hypertension are not fully understood, considerable evidence suggests that excess renal sodium reabsorption and a hypertensive shift of pressure natriuresis play a major role. Sympathetic activation appears to mediate at least part of the obesity-induced sodium retention and hypertension since adrenergic blockade or renal denervation markedly attenuates these changes. Recent observations suggest that leptin and its multiple interactions with neuropeptides in the hypothalamus may link excess weight gain with increased sympathetic activity. Leptin is produced mainly in adipocytes and is believed to regulate energy balance by acting on the hypothalamus to reduce food intake and to increase energy expenditure via sympathetic activation. Short-term administration of leptin into the cerebral ventricles increases renal sympathetic activity, and long-term leptin infusion at rates that mimic plasma concentrations found in obesity raises arterial pressure and heart rate via adrenergic activation in non-obese rodents. Transgenic mice overexpressing leptin also develop hypertension. Acute studies suggest that the renal sympathetic effects of leptin may depend on interactions with other neurochemical pathways in the hypothalamus, including the melanocortin-4 receptor (MC4-R. However, the role of this pathway in mediating the long-term effects of leptin on blood pressure is unclear. Also, it is uncertain whether there is resistance to the chronic renal sympathetic and blood pressure effects of leptin in obese subjects. In addition, leptin also has other cardiovascular and renal actions, such as stimulation of nitric oxide formation and improvement of insulin sensitivity, which may tend to reduce blood pressure in some conditions. Although the role of these mechanisms in human obesity has not been elucidated, this

  10. Myofibril ATPase activity of cardiac and skeletal muscle of exhaustively exercised rats.

    Science.gov (United States)

    Belcastro, A N; Turcotte, R; Rossiter, M; Secord, D; Maybank, P E

    1984-01-01

    The activation characteristics of Mg-ATP and Ca2+ on cardiac and skeletal muscle myofibril ATPase activity were studied in rats following a run to exhaustion. In addition, the effect of varying ionic strength was determined on skeletal muscle from exhausted animals. The exhausted group (E) ran at a speed of 25 m min-1 with an 8% incline. Myofibril ATPase activities for control (C) and E were determined with 1, 3 and 5 mM Mg-ATP and 1 and 10 microM Ca2+ at pH 7.0 and 30 degrees C. For control skeletal muscle, at 1 and 10 microM Ca2+, there was an increase in ATPase activity from 1 to 5 mM Mg-ATP (P less than 0.05). For E animals the myofibril ATPase activities at 10 microM Ca2+ and all Mg-ATP concentrations were similar to C (P greater than 0.05). At 1.0 microM Ca2+ and all Mg-ATP concentrations were similar to C (P greater than 0.05). At 1.0 microM Ca2+ the activities at 3 and 5 mM Mg-ATP were greater for the E animals (P less than 0.05). Increasing KCl concentrations resulted in greater inhibition for E animals. With cardiac muscle, the myofibril ATPase activities at 1.0 microM free Ca2+ were lower for E at all Mg-ATP levels (P less than 0.05). In contrast, at 10 microM Ca2+, the E group exhibited an elevated myofibril ATPase activity. The results indicate that Mg-ATP and Ca2+ activation of cardiac and skeletal muscle myofibril ATPase is altered with exhaustive exercise. PMID:6230276

  11. Effect of acute ozone induced airway inflammation on human sympathetic nerve traffic: a randomized, placebo controlled, crossover study.

    Directory of Open Access Journals (Sweden)

    Jens Tank

    Full Text Available BACKGROUND: Ozone concentrations in ambient air are related to cardiopulmonary perturbations in the aging population. Increased central sympathetic nerve activity induced by local airway inflammation may be one possible mechanism. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate this issue further, we performed a randomized, double-blind, cross-over study, including 14 healthy subjects (3 females, age 22-47 years, who underwent a 3 h exposure with intermittent exercise to either ozone (250 ppb or clean air. Induced sputum was collected 3 h after exposure. Nineteen to 22 hours after exposure, we recorded ECG, finger blood pressure, brachial blood pressure, respiration, cardiac output, and muscle sympathetic nerve activity (MSNA at rest, during deep breathing, maximum-inspiratory breath hold, and a Valsalva maneuver. While the ozone exposure induced the expected airway inflammation, as indicated by a significant increase in sputum neutrophils, we did not detect a significant estimated treatment effect adjusted for period on cardiovascular measurements. Resting heart rate (clean air: 59±2, ozone 60±2 bpm, blood pressure (clean air: 121±3/71±2 mmHg; ozone: 121±2/71±2 mmHg, cardiac output (clean air: 7.42±0.29 mmHg; ozone: 7.98±0.60 l/min, and plasma norepinephrine levels (clean air: 213±21 pg/ml; ozone: 202±16 pg/ml, were similar on both study days. No difference of resting MSNA was observed between ozone and air exposure (air: 23±2, ozone: 23±2 bursts/min. Maximum MSNA obtained at the end of apnea (air: 44±4, ozone: 48±4 bursts/min and during the phase II of the Valsalva maneuver (air: 64±5, ozone: 57±6 bursts/min was similar. CONCLUSIONS/SIGNIFICANCE: Our study suggests that acute ozone-induced airway inflammation does not increase resting sympathetic nerve traffic in healthy subjects, an observation that is relevant for environmental health. However, we can not exclude that chronic airway inflammation may contribute to sympathetic

  12. Chronic cardiac pressure overload induces adrenal medulla hypertrophy and increased catecholamine synthesis.

    Science.gov (United States)

    Schneider, Johanna; Lother, Achim; Hein, Lutz; Gilsbach, Ralf

    2011-06-01

    Increased activity of the sympathetic system is an important feature contributing to the pathogenesis and progression of chronic heart failure. While the mechanisms and consequences of enhanced norepinephrine release from sympathetic nerves have been intensely studied, the role of the adrenal gland in the development of cardiac hypertrophy and progression of heart failure is less well known. Thus, the aim of the present study was to determine the effect of chronic cardiac pressure overload in mice on adrenal medulla structure and function. Cardiac hypertrophy was induced in wild-type mice by transverse aortic constriction (TAC) for 8 weeks. After TAC, the degree of cardiac hypertrophy correlated significantly with adrenal weight and adrenal catecholamine storage. In the medulla, TAC caused an increase in chromaffin cell size but did not result in chromaffin cell proliferation. Ablation of chromaffin α(2C)-adrenoceptors did not affect adrenal weight or epinephrine synthesis. However, unilateral denervation of the adrenal gland completely prevented adrenal hypertrophy and increased catecholamine synthesis. Transcriptome analysis of microdissected adrenal medulla identified 483 up- and 231 downregulated, well-annotated genes after TAC. Among these genes, G protein-coupled receptor kinases 2 (Grk2) and 6 and phenylethanolamine N-methyltransferase (Pnmt) were significantly upregulated by TAC. In vitro, acetylcholine-induced Pnmt and Grk2 expression as well as enhanced epinephrine content was prevented by inhibition of nicotinic acetylcholine receptors and Ca(2+)/calmodulin-dependent signaling. Thus, activation of preganglionic sympathetic nerves innervating the adrenal medulla plays an essential role in inducing adrenal hypertrophy, enhanced catecholamine synthesis and induction of Grk2 expression after cardiac pressure overload.

  13. Theorems for Testing Local Activity of CNN and Application to Cardiac Equations

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The theorems for testing the local activity in one-port cellular neural/nonlinear network (CNN) cells with four local state variables are presented. Using the theorems computes the bifurcation diagrams of the cardiac Purkinje fiber (CPF) equations which describe the long-lasting action and pace-maker potentials of the Purkinje fiber of the heart. The computer simulation shows that periodic trajectories or convergent trajectories of the CPF Equations can be found if the corresponding cell parameters are located in a positive domain but nearby edge of chaos. In particular, a heart with approximate normal frequency of heartbeat but non-normal electrocardiogram may suddenly stop beating by slightly perturbing the parameters of the corresponding CPF Equations when the parameters are located nearby the edge of chaos in the bifurcation diagrams. This research seems to interpret reasonably the phenomena that patients with cardiac diseases might suddenly die without warning.

  14. Cardiac lipid content is unresponsive to a physical activity training intervention in type 2 diabetic patients, despite improved ejection fraction

    Directory of Open Access Journals (Sweden)

    Leiner Tim

    2011-05-01

    Full Text Available Abstract Background Increased cardiac lipid content has been associated with diabetic cardiomyopathy. We recently showed that cardiac lipid content is reduced after 12 weeks of physical activity training in healthy overweight subjects. The beneficial effect of exercise training on cardiovascular risk is well established and the decrease in cardiac lipid content with exercise training in healthy overweight subjects was accompanied by improved ejection fraction. It is yet unclear whether diabetic patients respond similarly to physical activity training and whether a lowered lipid content in the heart is necessary for improvements in cardiac function. Here, we investigated whether exercise training is able to lower cardiac lipid content and improve cardiac function in type 2 diabetic patients. Methods Eleven overweight-to-obese male patients with type 2 diabetes mellitus (age: 58.4 ± 0.9 years, BMI: 29.9 ± 0.01 kg/m2 followed a 12-week training program (combination endurance/strength training, three sessions/week. Before and after training, maximal whole body oxygen uptake (VO2max and insulin sensitivity (by hyperinsulinemic, euglycemic clamp was determined. Systolic function was determined under resting conditions by CINE-MRI and cardiac lipid content in the septum of the heart by Proton Magnetic Resonance Spectroscopy. Results VO2max increased (from 27.1 ± 1.5 to 30.1 ± 1.6 ml/min/kg, p = 0.001 and insulin sensitivity improved upon training (insulin stimulated glucose disposal (delta Rd of glucose improved from 5.8 ± 1.9 to 10.3 ± 2.0 μmol/kg/min, p = 0.02. Left-ventricular ejection fraction improved after training (from 50.5 ± 2.0 to 55.6 ± 1.5%, p = 0.01 as well as cardiac index and cardiac output. Unexpectedly, cardiac lipid content in the septum remained unchanged (from 0.80 ± 0.22% to 0.95 ± 0.21%, p = 0.15. Conclusions Twelve weeks of progressive endurance/strength training was effective in improving VO2max, insulin sensitivity

  15. Propranolol for Paroxysmal Sympathetic Hyperactivity with Lateralizing Hyperhidrosis after Stroke

    Directory of Open Access Journals (Sweden)

    Jason W. Siefferman

    2015-01-01

    Full Text Available Brain injury can lead to impaired cortical inhibition of the hypothalamus, resulting in increased sympathetic nervous system activation. Symptoms of paroxysmal sympathetic hyperactivity may include hyperthermia, tachycardia, tachypnea, vasodilation, and hyperhidrosis. We report the case of a 41-year-old man who suffered from a left middle cerebral artery stroke and subsequently developed central fever, contralateral temperature change, and hyperhidrosis. His symptoms abated with low-dose propranolol and then returned upon discontinuation. Restarting propranolol again stopped his symptoms. This represents the first report of propranolol being used for unilateral dysautonomia after stroke. Propranolol is a lipophilic nonselective beta-blocker which easily crosses the blood-brain barrier and may be used to treat paroxysmal sympathetic hyperactivity.

  16. Sympathetic innervation controls homeostasis of neuromuscular junctions in health and disease.

    Science.gov (United States)

    Khan, Muzamil Majid; Lustrino, Danilo; Silveira, Willian A; Wild, Franziska; Straka, Tatjana; Issop, Yasmin; O'Connor, Emily; Cox, Dan; Reischl, Markus; Marquardt, Till; Labeit, Dittmar; Labeit, Siegfried; Benoit, Evelyne; Molgó, Jordi; Lochmüller, Hanns; Witzemann, Veit; Kettelhut, Isis C; Navegantes, Luiz C C; Pozzan, Tullio; Rudolf, Rüdiger

    2016-01-19

    The distribution and function of sympathetic innervation in skeletal muscle have largely remained elusive. Here we demonstrate that sympathetic neurons make close contact with neuromuscular junctions and form a network in skeletal muscle that may functionally couple different targets including blood vessels, motor neurons, and muscle fibers. Direct stimulation of sympathetic neurons led to activation of muscle postsynaptic β2-adrenoreceptor (ADRB2), cAMP production, and import of the transcriptional coactivator peroxisome proliferator-activated receptor γ-coactivator 1α (PPARGC1A) into myonuclei. Electrophysiological and morphological deficits of neuromuscular junctions upon sympathectomy and in myasthenic mice were rescued by sympathicomimetic treatment. In conclusion, this study identifies the neuromuscular junction as a target of the sympathetic nervous system and shows that sympathetic input is crucial for synapse maintenance and function. PMID:26733679

  17. Chain Reconnections observed in Sympathetic Eruptions

    CERN Document Server

    Joshi, Navin Chandra; Magara, Tetsuya; Guo, Yang; Aulanier, Guillaume

    2016-01-01

    The nature of various plausible causal links between sympathetic events is still a controversial issue. In this work, we present multi-wavelength observations of sympathetic eruptions, associated flares and coronal mass ejections (CMEs) occurring on 2013 November 17 in two close-by active regions. Two filaments i.e., F1 and F2 are observed in between the active regions. Successive magnetic reconnections, caused by different reasons (flux cancellation, shear and expansion) have been identified during the whole event. The first reconnection occurred during the first eruption via flux cancellation between the sheared arcades overlying filament F2, creating a flux rope and leading to the first double ribbon solar flare. During this phase we observed the eruption of overlaying arcades and coronal loops, which leads to the first CME. The second reconnection is believed to occur between the expanding flux rope of F2 and the overlying arcades of the filament F1. We suggest that this reconnection destabilized the equi...

  18. An Autonomic Link Between Inhaled Diesel Exhaust and Impaired Cardiac Performance: Insight From Treadmill and Doubutamine Challenges in Heart Failure-Prone Rats

    Science.gov (United States)

    Background: Short-term exposure to vehicular emissions is associated with adverse cardiac events. Diesel exhaust (DE) is an ubiquitous air pollutant believed to provoke cardiac events partly through imbalance of the sympathetic and parasympathetic branches of the autonomic nervo...

  19. Controlling activation site density by low-energy far-field stimulation in cardiac tissue

    Science.gov (United States)

    Hörning, Marcel; Takagi, Seiji; Yoshikawa, Kenichi

    2012-06-01

    Tachycardia and fibrillation are potentially fatal arrhythmias associated with the formation of rotating spiral waves in the heart. Presently, the termination of these types of arrhythmia is achieved by use of antitachycardia pacing or cardioversion. However, these techniques have serious drawbacks, in that they either have limited application or produce undesirable side effects. Low-energy far-field stimulation has recently been proposed as a superior therapy. This proposed therapeutic method would exploit the phenomenon in which the application of low-energy far-field shocks induces a large number of activation sites (“virtual electrodes”) in tissue. It has been found that the formation of such sites can lead to the termination of undesired states in the heart and the restoration of normal beating. In this study we investigate a particular aspect of this method. Here we seek to determine how the activation site density depends on the applied electric field through in vitro experiments carried out on neonatal rat cardiac tissue cultures. The results indicate that the activation site density increases exponentially as a function of the intracellular conductivity and the level of cell isotropy. Additionally, we report numerical results obtained from bidomain simulations of the Beeler-Reuter model that are quantitatively consistent with our experimental results. Also, we derive an intuitive analytical framework that describes the activation site density and provides useful information for determining the ratio of longitudinal to transverse conductivity in a cardiac tissue culture. The results obtained here should be useful in the development of an actual therapeutic method based on low-energy far-field pacing. In addition, they provide a deeper understanding of the intrinsic properties of cardiac cells.

  20. Effects of autonomic balance and fluid and electrolyte changes on cardiac function in infarcted rats: A serial study of sexual dimorphism.

    Science.gov (United States)

    Souza, N S; Dos-Santos, R C; Silveira, Anderson Luiz Bezerra da; R, Sonoda-Côrtes; Gantus, Michel Alexandre Villani; Fortes, F S; Olivares, Emerson Lopes

    2016-04-01

    Premenopausal women are known to show lower incidence of cardiovascular disease than men. During myocardial infarction (MI), homeostatic responses are activated, including the sympathetic autonomic nervous system and the rennin-angiotensin-aldosterone system, which is related to the fluid and electrolyte balance, both aiming to maintain cardiac output. This study sought to perform a serial evaluation of sexual dimorphism in cardiac autonomic control and fluid and electrolyte balance during the development of MI-induced heart failure in rats. Experimental MI was induced in male (M) and female (F) adult (7-9 weeks of age) Wistar rats. The animals were placed in metabolic cages to assess fluid intake and urine volume 1 and 4 weeks after inducing MI (male myocardial infarction (MMI) and female myocardial infarction (FMI) groups). They subsequently underwent echocardiographic evaluation and spectral analysis of heart rate variability. After completing each protocol, the animals were killed for postmortem evaluation and histology. The MMI group showed earlier and more intense cardiac morphological and functional changes than the FMI group, although the extent of MI did not differ between groups (P > 0.05). The MMI group showed higher sympathetic modulation and sodium and water retention than the FMI group (P < 0.05), which may partly explain both the echocardiographic and pathological findings. Females subjected to infarction seem to show attenuation of sympathetic modulation, more favourable fluid and electrolyte balances, and better preserved cardiac function compared to males subjected to the same infarction model. PMID:26748814

  1. Sympathetic adaptations to one-legged training

    Science.gov (United States)

    Ray, C. A.

    1999-01-01

    The purpose of the present study was to determine the effect of leg exercise training on sympathetic nerve responses at rest and during dynamic exercise. Six men were trained by using high-intensity interval and prolonged continuous one-legged cycling 4 day/wk, 40 min/day, for 6 wk. Heart rate, mean arterial pressure (MAP), and muscle sympathetic nerve activity (MSNA; peroneal nerve) were measured during 3 min of upright dynamic one-legged knee extensions at 40 W before and after training. After training, peak oxygen uptake in the trained leg increased 19 +/- 2% (P training (108 +/- 5 to 96 +/- 5 beats/min and 132 +/- 8 to 119 +/- 4 mmHg, respectively, during the third minute of exercise; P training. However, MSNA was significantly less during the third minute of exercise after training (32 +/- 2 to 22 +/- 3 bursts/min; P training effect on MSNA remained when MSNA was expressed as bursts per 100 heartbeats. Responses to exercise in five untrained control subjects were not different at 0 and 6 wk. These results demonstrate that exercise training prolongs the decrease in MSNA during upright leg exercise and indicates that attenuation of MSNA to exercise reported with forearm training also occurs with leg training.

  2. [A case of prolonged paroxysmal sympathetic hyperactivity].

    Science.gov (United States)

    Yamamoto, Akiko; Ide, Shuhei; Iwasaki, Yuji; Kaga, Makiko; Arima, Masataka

    2016-03-01

    We report the case of a 4-year-old girl who presented with paroxysmal sympathetic hyperactivity (PSH), after developing severe hypoxic-ischemic-encephalopathy because of cardiopulmonary arrest. She showed dramatic paroxysmal sympathetic activity with dystonia. She was treated with wide variety of medications against PSH, which were found to be effective in previous studies. Among them, morphine, bromocriptine, propranolol, and clonidine were effective in reducing the frequency of her attacks while gabapentin, baclofen, dantrolene, and benzodiazepine were ineffective. Though the paroxysms decreased markedly after the treatment, they could not be completely controlled beyond 500 days. Following the treatment, levels of plasma catecholamines and their urinary metabolites decreased to normal during inter- paroxysms. However, once a paroxysm had recurred, these levels were again very high. This case study is considered significant for two rea- sons. One is that PSH among children have been rarely reported, and the other is that this case of prolonged PSH delineated the transition of plasma catecholamines during the treatment. The excitatory: inhibitory ratio (EIR) model proposed by Baguley was considered while dis- cussing drug sensitivity in this case. Accumulation of similar case studies will help establish more effective treatment strategies and elucidate the pathophysiology of PSH. PMID:27149743

  3. Early atherosclerosis and cardiac autonomic responses to mental stress: a population-based study of the moderating influence of impaired endothelial function

    OpenAIRE

    Juonala Markus; Ravaja Niklas; Hintsa Taina; Hintsanen Mirka; Chumaeva Nadja; Raitakari Olli T; Keltikangas-Järvinen Liisa

    2010-01-01

    Abstract Background Acute mental stress may contribute to the cardiovascular disease progression via autonomic nervous system controlled negative effects on the endothelium. The joint effects of stress-induced sympathetic or parasympathetic activity and endothelial function on atherosclerosis development have not been investigated. The present study aims to examine the interactive effect of acute mental stress-induced cardiac reactivity/recovery and endothelial function on the prevalence of c...

  4. Sympathetically evoked Ca2+ signaling in arterial smooth muscle

    Institute of Scientific and Technical Information of China (English)

    Wei-jin ZANG; Joseph ZACHARIA; Christine LAMONT; Withrow Gil WIER

    2006-01-01

    The sympathetic nervous system plays an essential role in the control of total peripheral vascular resistance and blood flow, by controlling the contraction of small arteries. Perivascular sympathetic nerves release ATP, norepinephrine (NE) and neuropeptide Y. This review summarizes our knowledge of the intracellular Ca2+ signals that are activated by ATP and NE, acting respectively on P2X1 and α1 adrenoceptors in arterial smooth muscle. Each neurotransmitter produces a unique type of post-synaptic Ca2+ signal and associated contraction. The neural release of ATP and NE is thought to vary markedly with the pattern of nerve activity, probably reflecting both pre- and post-synaptic mechanisms. Finally, we show that Ca2+ signaling during neurogenic contractions activated by trains of sympathetic nerve fiber action potentials are in fact significantly different from that elicited by simple bath application of exogenous neurotransmitters to isolated arteries (a common experimental technique), and end by identifying important questions remaining in our understanding of sympathetic neurotransmission and the physiological regulation of contraction of small arteries.

  5. A population-based lifestyle intervention to promote healthy weight and physical activity in people with cardiac disease: The PANACHE (Physical Activity, Nutrition And Cardiac HEalth study protocol

    Directory of Open Access Journals (Sweden)

    Allman-Farinelli Margaret

    2010-04-01

    Full Text Available Abstract Background Maintaining a healthy weight and undertaking regular physical activity are important for the secondary prevention of cardiovascular disease (CVD. However, many people with CVD are overweight and insufficiently active. In addition, in Australia only 20-30% of people requiring cardiac rehabilitation (CR for CVD actually attend. To improve outcomes of and access to CR the efficacy, effectiveness and cost-effectiveness of alternative approaches to CR need to be established. This research will determine the efficacy of a telephone-delivered lifestyle intervention, promoting healthy weight and physical activity, in people with CVD in urban and rural settings. The control group will also act as a replication study of a previously proven physical activity intervention, to establish whether those findings can be repeated in different urban and rural locations. The cost-effectiveness and acceptability of the intervention to CR staff and participants will also be determined. Methods/Design This study is a randomised controlled trial. People referred for CR at two urban and two rural Australian hospitals will be invited to participate. The intervention (healthy weight group will participate in four telephone delivered behavioural coaching and goal setting sessions over eight weeks. The coaching sessions will be on weight, nutrition and physical activity and will be supported by written materials, a pedometer and two follow-up booster telephone calls. The control (physical activity group will participate in a six week intervention previously shown to increase physical activity, consisting of two telephone delivered behavioural coaching and goal setting sessions on physical activity, supported by written materials, a pedometer and two booster phone calls. Data will be collected at baseline, eight weeks and eight months for the intervention group (baseline, six weeks and six months for the control group. The primary outcome is weight change

  6. Inducible Conditional Vascular-Specific Overexpression of Peroxisome Proliferator-Activated Receptor Beta/Delta Leads to Rapid Cardiac Hypertrophy

    Science.gov (United States)

    Wagner, Kay-Dietrich; Vukolic, Ana; Baudouy, Delphine; Michiels, Jean-François

    2016-01-01

    Peroxisome proliferator-activated receptors are nuclear receptors which function as ligand-activated transcription factors. Among them, peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) is highly expressed in the heart and thought to have cardioprotective functions due to its beneficial effects in metabolic syndrome. As we already showed that PPARβ/δ activation resulted in an enhanced cardiac angiogenesis and growth without impairment of heart function, we were interested to determine the effects of a specific activation of PPARβ/δ in the vasculature on cardiac performance under normal and in chronic ischemic heart disease conditions. We analyzed the effects of a specific PPARβ/δ overexpression in endothelial cells on the heart using an inducible conditional vascular-specific mouse model. We demonstrate that vessel-specific overexpression of PPARβ/δ induces rapid cardiac angiogenesis and growth with an increase in cardiomyocyte size. Upon myocardial infarction, vascular overexpression of PPARβ/δ, despite the enhanced cardiac vessel formation, does not protect against chronic ischemic injury. Our results suggest that the proper balance of PPARβ/δ activation in the different cardiac cell types is required to obtain beneficial effects on the outcome in chronic ischemic heart disease. PMID:27057154

  7. Signs of cardiac autonomic imbalance and proarrhythmic remodeling in FTO deficient mice.

    Directory of Open Access Journals (Sweden)

    Luca Carnevali

    Full Text Available In humans, variants of the fat mass and obesity associated (FTO gene have recently been associated with obesity. However, the physiological function of FTO is not well defined. Previous investigations in mice have linked FTO deficiency to growth retardation, loss of white adipose tissue, increased energy metabolism and enhanced systemic sympathetic activation. In this study we investigated for the first time the effects of global knockout of the mouse FTO gene on cardiac function and its autonomic neural regulation. ECG recordings were acquired via radiotelemetry in homozygous knockout (n = 12 and wild-type (n = 8 mice during resting and stress conditions, and analyzed by means of time- and frequency-domain indexes of heart rate variability. In the same animals, cardiac electrophysiological properties (assessed by epicardial mapping and structural characteristics were investigated. Our data indicate that FTO knockout mice were characterized by (i higher heart rate values during resting and stress conditions, (ii heart rate variability changes (increased LF to HF ratio, (iii larger vulnerability to stress-induced tachyarrhythmias, (iv altered ventricular repolarization, and (v cardiac hypertrophy compared to wild-type counterparts. We conclude that FTO deficiency in mice leads to an imbalance of the autonomic neural modulation of cardiac function in the sympathetic direction and to a potentially proarrhythmic remodeling of electrical and structural properties of the heart.

  8. Sympathetic nervous dysregulation in the absence of systolic left ventricular dysfunction in a rat model of insulin resistance with hyperglycemia

    OpenAIRE

    Suuronen Erik J; Harper Mary-Ellen; Radziuk Jerry; Thackeray James T; Ascah Kathryn J; Beanlands Rob S; DaSilva Jean N

    2011-01-01

    Abstract Background Diabetes mellitus is strongly associated with cardiovascular dysfunction, derived in part from impairment of sympathetic nervous system signaling. Glucose, insulin, and non-esterified fatty acids are potent stimulants of sympathetic activity and norepinephrine (NE) release. We hypothesized that sustained hyperglycemia in the high fat diet-fed streptozotocin (STZ) rat model of sustained hyperglycemia with insulin resistance would exhibit progressive sympathetic nervous dysf...

  9. Mechanisms of electrical activation and conduction in the gastrointestinal system: lessons from cardiac electrophysiology

    Directory of Open Access Journals (Sweden)

    Gary eTse

    2016-05-01

    Full Text Available The gastrointestinal (GI tract is an electrically excitable organ system containing multiple cell types, which coordinate electrical activity propagating through this tract. Disruption in its normal electrophysiology is observed in a number of GI motility disorders. However, this is not well characterized and the field of GI electrophysiology is much less developed compared to the cardiac field. The aim of this article is to use the established knowledge of cardiac electrophysiology to shed light on the mechanisms of electrical activation and propagation along the GI tract, and how abnormalities in these processes lead to motility disorders and suggest better treatment options based on this improved understanding. In the first part of the article, the ionic contributions to the generation of GI slow wave and the cardiac action potential (AP are reviewed. Propagation of these electrical signals can be described by the core conductor theory in both systems. However, specifically for the GI tract, the following unique properties are observed: changes in slow wave frequency along its length, periods of quiescence, synchronization in short distances and desynchronization over long distances. These are best described by a coupled oscillator theory. Other differences include the diminished role of gap junctions in mediating this conduction in the GI tract compared to the heart. The electrophysiology of conditions such as gastroesophageal reflux disease and gastroparesis, and functional problems such as irritable bowel syndrome are discussed in detail, with reference to ion channel abnormalities and potential therapeutic targets. A deeper understanding of the molecular basis and physiological mechanisms underlying GI motility disorders will enable the development of better diagnostic and therapeutic tools and the advancement of this field.

  10. Relation of chaos activity characteristics of the cardiac system with the evolution of species

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    According to the nonlinear theory, the experiments have been conducted on sample ECG (electrocardiogram) signals of healthy human beings, coronary heart disease patients and adult canines. On the basis of the analyses of the power spectra, the computation of the correlation dimension and the Lyapunov exponent to a large number of ECG signals, the following conclusions are shown: through the comparative research, (1( the analyses of the power spectra, the computation of the correlation dimension and the Lyapunov exponent to the ECG signals reflect the whole dynamic characteristics of the hearts, and they may become a new method of researching ECG quantitatively to an early diagnose of heart disease. (2( Under normal physiological conditions the cardiac activities are chaotic, while under pathologic conditions the cardiac activities approach regularity. (3( On the basis of the comparative research of human beings and canines, it is revealed that chaos may be a quantitative index to measure the evolution of species. This conclusion would supply a new cut-in point to elaborate the Darwin theory, and it would enable us to explain the life theory renewably using the basic principle of nonlinear theory.

  11. Effect of dietary fats on the lipid composition and enzyme activities of rat cardiac sarcolemma.

    Science.gov (United States)

    Awad, T B; Chattopadhyay, J P

    1983-09-01

    The effect of dietary lipids on the lipid composition and the activities of some enzymes of cardiac sarcolemma were studied. Feeding rats coconut oil--rich diet for 4 weeks resulted in a significant decrease in 5'-nucleotidase, phosphodiesterase I and p-nitrophenylphosphatase activity of cardiac sarcolemma as compared with feeding rats safflower oil. Sarcolemma from animals fed coconut oil diet contained a significantly lower concentration of total polyunsaturated fatty acids and a higher concentration of total monounsaturated fatty acids than that from rats fed safflower oil. Most of the alterations in polyunsaturated fatty acids were found in 20:4, whereas those of the monounsaturates were found in 18:1. Among all the phosphoglycerides, the fatty acid composition of the phosphatidylcholine exhibited the largest alterations as a result of coconut oil feeding. No dietary effect was observed in the sarcolemma content of cholesterol and phospholipid. These studies clearly indicate that manipulation of dietary lipids influences both the fatty acid composition and some functional properties of the sarcolemma membranes.

  12. Bifurcations in a nonlinear model of the baroreceptor-cardiac reflex

    Science.gov (United States)

    Seidel, H.; Herzel, H.

    1998-04-01

    We investigate the dynamic properties of a nonlinear model of the human cardio-baroreceptor control loop. As a new feature we use a phase effectiveness curve to describe the experimentally well-known phase dependency of the cardiac pacemaker's sensitivity to neural activity. We show that an increase of sympathetic time delays leads via a Hopf bifurcation to sustained heart rate oscillations. For increasing baroreflex sensitivity or for repetitive vagal stimulation we observe period-doubling, toroidal oscillations, chaos, and entrainment between the rhythms of the heart and the control loop. The bifurcations depend crucially on the involvement of the cardiac pacemaker's phase dependency. We compare the model output with experimental data from electrically stimulated anesthetized dogs and discuss possible implications for cardiac arrhythmias.

  13. Skin sympathetic outflow during head-down neck flexion in humans.

    Science.gov (United States)

    Ray, C A; Hume, K M; Shortt, T L

    1997-09-01

    We have previously demonstrated increases in muscle sympathetic nerve activity during head-down neck flexion (HDNF). The purpose of the present study was to determine if HDNF also activates skin sympathetic nerve activity (SSNA). SSNA, heart rate, arterial pressure, skin blood flow, calf blood flow, and calculated calf vascular resistance (mean arterial pressure/calf blood flow) were determined in 12 subjects during 3 min of baseline (lying prone with chin supported) and 3 min of HDNF. There were no significant changes in heart rate and arterial pressures during HDNF; however, diastolic and mean arterial pressure tended to increase slightly. Calf blood flow decreased 22% and calf vascular resistance increased 46% during HDNF. SSNA did not significantly change during HDNF. In three subjects we measured both muscle and skin sympathetic nerve activity during HDNF. In these trials, muscle sympathetic nerve activity consistently increased, but SSNA did not. The results indicate that HDNF in humans activates muscle sympathetic nerve activity, but does not activate SSNA. Thus vestibular stimulation may elicit differential activation of sympathetic outflow in humans. PMID:9321897

  14. The effect of space microgravity on the physiological activity of mammalian resident cardiac stem cells

    Science.gov (United States)

    Belostotskaya, Galina; Zakharov, Eugeny

    Prolonged exposure to weightlessness during space flights is known to cause depression of heart function in mammals. The decrease in heart weight and its remodeling under the influence of prolonged weightlessness (or space microgravity) is assumed to be due to both morphological changes of working cardiomyocytes and their progressive loss, as well as to possible depletion of resident cardiac stem cells (CSCs) population, or their inability to self-renewal and regeneration of muscle tissue under conditions of weightlessness. We have previously shown that the presence of different maturity clones formed by resident CSCs not only in culture but also in the mammalian myocardium can be used as an indicator of the regenerative activity of myocardial cells [Belostotskaya, et al., 2013: 2014]. In this study, we were interested to investigate whether the 30-day near-Earth space flight on the spacecraft BION-M1 affects the regenerative potential of resident CSCs. Immediately after landing of the spacecraft, we had examined the presence of resident c-kit+, Sca-1+ and Isl1+ CSCs and their development in suspension of freshly isolated myocardial cells of C57BL mice in comparison to controls. Cardiac cell suspension was obtained by enzymatic digestion of the heart [Belostotskaya and Golovanova, 2014]. Immunocytochemically stained preparations of fixed cells were analyzed with confocal microscope Leica TCS SP5 (Germany) in the Resource Center of St-Petersburg State University. CSCs were labeled with appropriate antibodies. CSCs differentiation into mature cardiomyocytes was verified using antibodies to Sarcomeric α-Actinin and Cardiac Troponin T. Antibodies to Connexin43 were used to detect cell-cell contacts. All antibodies were conjugated with Alexa fluorochromes (488, 532, 546, 568, 594 and/or 647 nm), according to Zenon-technology (Invitrogen). It has been shown that, under identical conditions of cell isolation, more complete digestion of heart muscle was observed in

  15. Adoption of community-based cardiac rehabilitation programs and physical activity following phase III cardiac rehabilitation in Scotland: a prospective and predictive study.

    Science.gov (United States)

    Sniehotta, Falko F; Gorski, Charlotta; Araujo-Soares, Vera

    2010-09-01

    Little is known about levels of physical activity and attendance at phase IV community-based Cardiac Rehabilitation (CR) programs following completion of exercise-focussed, hospital-based phase III CR. This study aims to test, compare and combine the predictive utility of the Common-Sense Self-Regulation Model (CS-SRM) and the extended Theory of Planned Behaviour (TPB) with action planning for two rehabilitation behaviours: physical activity and phase IV CR attendance. Individuals diagnosed with coronary heart disease (n = 103) completed baseline measures of illness perceptions, intentions, perceived behavioural control (PBC), action planning and past physical activity in the last week of a phase III CR program, and 95 participants completed follow-up measures of physical activity and attended phase IV CR (objectively confirmed) 2 months later. Only one predictor (PBC/cyclical timeline) significantly predicted levels and change of physical activity. While illness perceptions were not predictive of phase IV CR attendance, the extended TPB model showed good predictive power with action planning and intention as the most powerful predictors. Amongst participants who planned when and where to attend phase IV CR at the end of phase III rehabilitation, 65.9% subsequently attended a phase IV CR program compared to only 18.5% of those who had not made a plan. This study adds to our understanding of cardiac rehabilitation behaviour after completion of health service delivered programs. Comparing theoretical models and rehabilitation behaviours contributes to the development of behaviour theory.

  16. Prolonged Paroxysmal Sympathetic Storming Associated with Spontaneous Subarachnoid Hemorrhage

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2013-01-01

    Full Text Available Paroxysmal sympathetic storming (PSS is a rare disorder characterized by acute onset of nonstimulated tachycardia, hypertension, tachypnea, hyperthermia, external posturing, and diaphoresis. It is most frequently associated with severe traumatic brain injuries and has been reported in intracranial tumors, hydrocephalous, severe hypoxic brain injury, and intracerebral hemorrhage. Although excessive release of catecholamine and therefore increased sympathetic activities have been reported in subarachnoid hemorrhage (SAH, there is no descriptive report of PSS primarily caused by spontaneous SAH up to date. Here, we report a case of prolonged PSS in a patient with spontaneous subarachnoid hemorrhage and consequent vasospasm. The sympathetic storming started shortly after patient was rewarmed from hypothermia protocol and symptoms responded to Labetalol, but intermittent recurrence did not resolve until 3 weeks later with treatment involving Midazolam, Fentanyl, Dexmedetomidine, Propofol, Bromocriptine, and minimizing frequency of neurological and vital checks. In conclusion, prolonged sympathetic storming can also be caused by spontaneous SAH. In this case, vasospasm might be a precipitating factor. Paralytics and hypothermia could mask the manifestations of PSS. The treatment of the refractory case will need both timely adjustment of medications and minimization of exogenous stressors or stimuli.

  17. The Mikamo lecture. Role of higher nervous activity in sudden cardiac death.

    Science.gov (United States)

    Lown, B

    1990-06-01

    The brain receives and catalogues myriads of information from within and without the organism. These inputs promote neural integration of bodily function through a multiplicity of cybernetic feedback loops. Higher nervous activity shapes the contours of perceived well-being and determines the course and progress of disease. Behavioral and neural factors play an important role in cardiovascular function and are especially relevant to the problem of sudden cardiac death (SCD). Clinical data attesting to the role of biobehavioral factors in SCD derive from a diversity of sources. It has long been known that bereavement increases the prevalence of cardiac fatality. Business failure rates are strongly related to increased mortality among persons aged 55 and over. Recession in economic activity, with increasing unemployment, is associated with augmented death rates from ischemic heart disease. In extensive surveys conducted among London civil servants, Rose and Marmot found not only the level but the type of employment to be a factor determining coronary heart disease mortality. Blue collar workers had a 3.6 times greater chance of dying from heart disease than an age-matched population in the higher ranks of civil service. A man's employment status was a stronger predictor of risk for dying from coronary heart disease than any of the usual risk factors, such as smoking, blood pressure, height-weight ratio, leisure time activities, glucose tolerance, or plasma cholesterol. Operation of behavioral factors is also suggested by the time of occurrence of sudden death. Among 3,983 men followed for more than 30 years, Rabkin and co-workers observed an excess proportion of fatalities on Mondays. No such pattern was noted for cancer mortality. Not only the day of the week but the time of day appears to be a factor. Muller and co-workers found a significant preponderance in the occurrence of myocardial infarction and sudden death from 6:00 AM to noon. They could not implicate

  18. Brain renin angiotensin system in cardiac hypertrophy and failure

    Directory of Open Access Journals (Sweden)

    Luciana eCampos

    2012-01-01

    Full Text Available Brain renin-angiotensin system (RAS is significantly involved in the roles of the endocrine RAS in cardiovascular regulation. Our studies indicate that the brain RAS participates in the development of cardiac hypertrophy and fibrosis through sympathetic activation. Inhibition of sympathetic hyperactivity after myocardial infarction through suppression of the brain RAS appears beneficial. The brain RAS is involved in the modulation of circadian rhythms of arterial pressure, contributing to nondipping hypertension. We conclude that the brain RAS in pathophysiological states interacts synergistically with the chronically overactive RAS through a positive biofeedback in order to maintain a state of alert diseased conditions, such as cardiac hypertrophy and failure. Therefore, targeting brain RAS with drugs such as angiotensin converting inhibitors or receptor blockers having increased brain penetrability could be of advantage. These RAS-targeting drugs are first-line therapy for all heart failure patients. Since the RAS has both endocrine and local tissue components, RAS drugs are being developed to attain increased tissue penetrability and volume of distribution and consequently an efficient inhibition of both RAS components.

  19. CHAIN RECONNECTIONS OBSERVED IN SYMPATHETIC ERUPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Navin Chandra; Magara, Tetsuya [School of Space Research, Kyung Hee University, Yongin, Gyeonggi-Do, 446-701 (Korea, Republic of); Schmieder, Brigitte; Aulanier, Guillaume [LESIA, Observatoire de Paris, PSL Research University, CNRS Sarbonne Universités, Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Jansson, F-92195 Meudon (France); Guo, Yang, E-mail: navin@khu.ac.kr, E-mail: njoshi98@gmail.com [School of Astronomy and Space Science, Nanjing University, 210023 Nanjing (China)

    2016-04-01

    The nature of various plausible causal links between sympathetic events is still a controversial issue. In this work, we present multiwavelength observations of sympathetic eruptions, associated flares, and coronal mass ejections (CMEs) occurring on 2013 November 17 in two close active regions. Two filaments, i.e., F1 and F2, are observed in between the active regions. Successive magnetic reconnections, caused for different reasons (flux cancellation, shear, and expansion) have been identified during the whole event. The first reconnection occurred during the first eruption via flux cancellation between the sheared arcades overlying filament F2, creating a flux rope and leading to the first double-ribbon solar flare. During this phase, we observed the eruption of overlying arcades and coronal loops, which leads to the first CME. The second reconnection is believed to occur between the expanding flux rope of F2 and the overlying arcades of filament F1. We suggest that this reconnection destabilized the equilibrium of filament F1, which further facilitated its eruption. The third stage of reconnection occurred in the wake of the erupting filament F1 between the legs of the overlying arcades. This may create a flux rope and the second double-ribbon flare and a second CME. The fourth reconnection was between the expanding arcades of the erupting filament F1 and the nearby ambient field, which produced the bi-directional plasma flows both upward and downward. Observations and a nonlinear force-free field extrapolation confirm the possibility of reconnection and the causal link between the magnetic systems.

  20. Adiponectin is required for cardiac MEF2 activation during pressure overload induced hypertrophy.

    Science.gov (United States)

    Dadson, Keith; Turdi, Subat; Hashemi, Sarah; Zhao, Jianzhong; Polidovitch, Nazar; Beca, Sanja; Backx, Peter H; McDermott, John C; Sweeney, Gary

    2015-09-01

    Cardiomyocyte (CM) hypertrophy and increased heart mass in response to pressure overload are associated with hyper-activation of the myocyte enhancer factor-2 (MEF2) family of transcriptional regulators, and concomitant initiation of the fetal gene program. Adiponectin, an adipokine that is reduced in individuals with obesity and diabetes, has been characterized both as a negative regulator or permissive factor in cardiac hypertrophy. We therefore sought to analyze temporal regulation of MEF2 activity in response to pressure overload (PO) and changes in adiponectin status. To address this we crossed a well characterized transgenic MEF2 "sensor" mouse (MEF2-lacZ) with adiponectin null mice (Ad-KO) to create compound MEF2 lacZ/Ad-KO mice. Initially, we established that transverse aortic banding induced PO in wild-type (WT) mice increased heart mass and CM hypertrophy from 1 to 4weeks following surgery, indicated by increased CM diameter and heart weight/tibia length ratio. This was associated with cardiac dysfunction determined by echocardiography. Hypertrophic changes and dysfunction were observed in Ad-KO mice 4weeks following surgery. MEF2 lacZ activity and endogenous ANF mRNA levels, used as indicators of hypertrophic gene activation, were both robustly increased in WT mice after MTAB but attenuated in the Ad-KO background. Furthermore, activation of the pro-hypertrophic molecule p38 was increased following MTAB surgery in WT mice, but not in Ad-KO animals, and treatment of primary isolated CM with recombinant adiponectin induced p38 phosphorylation in a time dependent manner. Adiponectin also increased MEF2 activation in primary cardiomyocytes, an effect attenuated by p38 MAPK inhibition. In conclusion, our data indicate that robust hypertrophic MEF2 activation in the heart in vivo requires a background of adiponectin signaling and that adiponectin signaling in primary isolated CM directly enhances MEF2 activity through activation of p38 MAPK. We conclude that

  1. Vasomotor sympathetic outflow in the muscle metaboreflex in low birth weight young adults

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    Chifamba J

    2015-05-01

    Full Text Available Jephat Chifamba,1 Brilliant Mbangani,1 Casper Chimhete,1 Lenon Gwaunza,1 Larry A Allen,2 Herbert Mapfumo Chinyanga1 1Department of Physiology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe; 2Section of Advanced Heart Failure and Transplantation, University of Colorado School of Medicine, Aurora, CO, USA Abstract: A growing body of evidence suggests that low birth weight (LBW offspring are associated with long-term structural and functional changes in cardiovascular and neuroendocrine systems. We tested the hypothesis that muscle metaboreflex activation produces exaggerated responses in cardiac autonomic tone (represented by heart rate variability ratio and cutaneous vascular sympathetic tone (represented by plethysmography pulse wave amplitude in LBW compared to normal birth weight (NBW young adults. We recruited 23 LBW (18 females and five males and 23 NBW (14 females and nine males University of Zimbabwe students with neonatal clinical cards as proof of birth weight at term. Resting electrocardiogram, pulse waves, and blood pressures were recorded. Participants then underwent a static/isometric handgrip exercise until fatigue and a post-exercise circulatory arrest period of 2 minutes. We observed (results mean ± standard deviation a greater mean increase in heart rate variability ratio from baseline to exercise for LBW compared to NBW individuals (1.015±1.034 versus [vs] 0.119±0.789, respectively; P<0.05. We also observed a greater mean decrease in plethysmography pulse wave amplitude from baseline to exercise (-1.32±1.064 vs -0.735±0.63; P<0.05 and from baseline to post-exercise circulatory arrest (-0.932±0.998 vs -0.389±0.563; P<0.05 for LBW compared to NBW individuals. We conclude that LBW may be associated with an exaggerated sympathetic discharge in response to muscle metaboreflex. Keywords: blood pressure, heart rate variability, plethysmography pulse

  2. α2A-adrenoceptors, but not nitric oxide, mediate the peripheral cardiac sympatho-inhibition of moxonidine.

    Science.gov (United States)

    Cobos-Puc, Luis E; Aguayo-Morales, Hilda; Silva-Belmares, Yesenia; González-Zavala, Maria A; Centurión, David

    2016-07-01

    Moxonidine centrally inhibits the sympathetic activity through the I1-imidazoline receptor and nitric oxide. In addition, inhibits the peripheral cardiac sympathetic outflow by α2-adrenoceptors/I1-imidazoline receptors, although the role of α2-adrenoceptor subtypes or nitric oxide in the cardiac sympatho-inhibition induced by moxonidine are unknown. Therefore, the cardiac sympatho-inhibition induced by moxonidine (10μg/kgmin) was evaluated before and after of the treatment with the following antagonists/inhibitor: (1) BRL 44408, (300μg/kg, α2A), imiloxan, (3000μg/kg, α2B), and JP-1302, (300μg/kg, α2C), in animals pretreated with AGN 192403 (3000μg/kg, I1 antagonist); (2) N(ω)-nitro-l-arginine methyl ester (l-NAME; 34, 100, and 340μg/kgmin); and (3) the combinations of the highest dose of l-NAME plus AGN 192403 or BRL 44408. Additionally, the expression of the neuronal (nNOS) and inducible (iNOS) nitric oxide synthase in the stellate ganglion was determined after treatment with moxonidine (i.p. 0.56mg/kg daily, during one week). The cardiac sympatho-inhibition of 10μg/kgmin moxonidine was: (1) unaffected by imiloxan and JP-1302, under pretreatment with AGN 192403, or l-NAME (34, 100 and 340μg/kgmin) given alone; (2) partially antagonized by the combination of 340 μg/kgmin l-NAME plus BRL 44408; and (3) abolished by BRL 44408 under treatment with AGN 192403. Furthermore, moxonidine did not modify the nNOS or iNOS protein expression in the stellate ganglion, the main source of postganglionic sympathetic neurons innervating the heart. In conclusion, our results suggest that the peripheral cardiac sympatho-inhibition induced by moxonidine is mediated by α2A-adrenoceptor subtype but not by nitric oxide. PMID:27112661

  3. α2A-adrenoceptors, but not nitric oxide, mediate the peripheral cardiac sympatho-inhibition of moxonidine.

    Science.gov (United States)

    Cobos-Puc, Luis E; Aguayo-Morales, Hilda; Silva-Belmares, Yesenia; González-Zavala, Maria A; Centurión, David

    2016-07-01

    Moxonidine centrally inhibits the sympathetic activity through the I1-imidazoline receptor and nitric oxide. In addition, inhibits the peripheral cardiac sympathetic outflow by α2-adrenoceptors/I1-imidazoline receptors, although the role of α2-adrenoceptor subtypes or nitric oxide in the cardiac sympatho-inhibition induced by moxonidine are unknown. Therefore, the cardiac sympatho-inhibition induced by moxonidine (10μg/kgmin) was evaluated before and after of the treatment with the following antagonists/inhibitor: (1) BRL 44408, (300μg/kg, α2A), imiloxan, (3000μg/kg, α2B), and JP-1302, (300μg/kg, α2C), in animals pretreated with AGN 192403 (3000μg/kg, I1 antagonist); (2) N(ω)-nitro-l-arginine methyl ester (l-NAME; 34, 100, and 340μg/kgmin); and (3) the combinations of the highest dose of l-NAME plus AGN 192403 or BRL 44408. Additionally, the expression of the neuronal (nNOS) and inducible (iNOS) nitric oxide synthase in the stellate ganglion was determined after treatment with moxonidine (i.p. 0.56mg/kg daily, during one week). The cardiac sympatho-inhibition of 10μg/kgmin moxonidine was: (1) unaffected by imiloxan and JP-1302, under pretreatment with AGN 192403, or l-NAME (34, 100 and 340μg/kgmin) given alone; (2) partially antagonized by the combination of 340 μg/kgmin l-NAME plus BRL 44408; and (3) abolished by BRL 44408 under treatment with AGN 192403. Furthermore, moxonidine did not modify the nNOS or iNOS protein expression in the stellate ganglion, the main source of postganglionic sympathetic neurons innervating the heart. In conclusion, our results suggest that the peripheral cardiac sympatho-inhibition induced by moxonidine is mediated by α2A-adrenoceptor subtype but not by nitric oxide.

  4. Cardiac sodium channelopathies

    NARCIS (Netherlands)

    A.S. Amin; A. Asghari-Roodsari; H.L. Tan

    2010-01-01

    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (I-Na) during phase 0 of the cardiac action potential. The importance of I-Na for normal cardiac electrical activity is reflected by the high incidence of

  5. Effect of transcutaneous electric stimulation on the cardiac electrical activity in New Zealand white rabbits

    Directory of Open Access Journals (Sweden)

    Wang ZHANG

    2015-10-01

    Full Text Available Objective To study the effect of transcutaneous electric stimulation on the cardiac electrical activity in New Zealand white rabbits, in order to search a safety threshold for clinical electrical stimulation therapy, as to provide the theoretical basis for the design of in vitro pacemaker. Methods New Zealand white rabbits were randomly assigned into 17 groups (6 each. Rabbits in 16 experimental groups were given 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 and 80V electrical stimulation, respectively, with the stimulating site designated at epigastric region. BL -420F biological function experimental system was employed to supply the power and acquire the ECG, with the output pulse electrical stimulation frequency set at 270 times/minute, and the stimulating wave as square wave. A control group was set, in which the stimulating voltage was set to 35V, the stimulant anode was located in the anterior chest area, and the cathode was on the skin surface of back corresponding to the site of the heart, and the rest was the same as in experimental groups. Results No stimulation rhythm was observed in rabbits of those experimental groups with voltage ≤35V, but all stimulation rhythm was observed in rabbits of control group. No arrhythmia occurred in rabbits of those experimental groups with voltage ≤30V, while the heart rate was slowed down after stimulation in rabbits of the experimental groups with voltage ≥45V stimulation. In rabbits receiving stimulation with voltage ≤35V there was no dystropy or light dystropy, but with no visible injury to the local tissues. No visible injury was observed in the rabbits undergoing stimulation with voltage ≤40V. Conclusion Pulse electric stimulation with voltage ≤35V in the epigastric region would not affect the cardiac electrical activity in rabbits, while stimulation with 35V will lead to all pacing rhythm of the heart without affecting the cardiac electrical activity in rabbits

  6. Physical activity and sudden cardiac death in elders--a Croatian study.

    Science.gov (United States)

    Duraković, Zijad; Duraković, Marjeta Misigoj; Skavić, Josip; Gojanović, Marija Definis

    2011-03-01

    The paper deals with the sudden cardiac death in elders due to physical activity in Croatia and to compare it to other population groups who practice physical activity. The data are a part of a retrospective study dealing with 59 sudden death due to physical activity in men in Croatia: from January 1, 1988 to December 31, 2008. Fifteen aged 65 to 82 years were recreationally engaged in physical activity: six in swimming, four in tennis, one in driving a bicycle, one in jogging, two in bowling and one died during sexual act. Only one had symptoms of pectoral angina, two suffered from arterial hypertension, and two had congestive heart failure. Eleven were without symptoms before exercise. At forensic autopsy, fourteen had coronary heart disease, seven had critical coronary artery stenosis, three had occluded left descendens anterior coronary artery and four critical coronary stenosis, four had a recent myocardial infarctions, and eleven had myocardial scars due to previous myocardial infarctions. Twelve of them had left ventricular hypertrophy: 15-25 mm. In Croatia, about 7per cent of the entire male population undertake recreational physical activity, while 13 per cent of them are elders. A sudden cardiac death due to recreational physical activity in elders reached 1.71/100 000 yearly, in the entire male population engaged in recreational physical exercise: 0.75/100 000 (p = 0.05730), in the total male population aged 15-40 engaged in sports and recreational physical exercise: 0.57/100.0000 (p = 0.00387), in young athletes: 0.15/100 000 (p = 0.00000). Medical examination of all elderly persons has to be done before starting of recreational physical activity: by clinical examination, searching for risk factors for atherosclerosis, performing ECG at rest, stress ECG, and echocardiography and to repeat the medical examination at least once a year Physical activity should start with a warm-up period and with a gradually increasing load, and usually not to exceed 6

  7. Impaired cardiac SIRT1 activity by carbonyl stress contributes to aging-related ischemic intolerance.

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    Chunhu Gu

    Full Text Available Reactive aldehydes can initiate protein oxidative damage which may contribute to heart senescence. Sirtuin 1 (SIRT1 is considered to be a potential interventional target for I/R injury management in the elderly. We hypothesized that aldehyde mediated carbonyl stress increases susceptibility of aged hearts to ischemia/reperfusion (I/R injury, and elucidate the underlying mechanisms with a focus on SIRT1. Male C57BL/6 young (4-6 mo and aged (22-24 mo mice were subjected to myocardial I/R. Cardiac aldehyde dehydrogenase (ALDH2, SIRT1 activity and protein carbonyls were assessed. Our data revealed that aged heart exhibited increased endogenous aldehyde/carbonyl stress due to impaired ALDH2 activity concomitant with blunted SIRT1 activity (P<0.05. Exogenous toxic aldehydes (4-HNE exposure in isolated cardiomyocyte verified that aldehyde-induced carbonyl modification on SIRT1 impaired SIRT1 activity leading to worse hypoxia/reoxygenation (H/R injury, which could all be rescued by Alda-1 (ALDH2 activator (all P<0.05. However, SIRT1 inhibitor blocked the protective effect of Alda-1 on H/R cardiomyocyte. Interestingly, myocardial I/R leads to higher carbonylation but lower activity of SIRT1 in aged hearts than that seen in young hearts (P<0.05. The application of Alda-1 significantly reduced the carbonylation on SIRT1 and markedly improved the tolerance to in vivo I/R injury in aged hearts, but failed to protect Sirt1(+/- knockout mice against myocardial I/R injury. This was verified by Alda-1 treatment improved postischemic contractile function recovery in ex vivo perfused aged but not in Sirt1(+/- hearts. Thus, aldehyde/carbonyl stress is accelerated in aging heart. These results provide a new insight that impaired cardiac SIRT1 activity by carbonyl stress plays a critical role in the increased susceptibility of aged heart to I/R injury. ALDH2 activation can restore this aging-related myocardial ischemic intolerance.

  8. Secondary prevention through cardiac rehabilitation: physical activity counselling and exercise training: key components of the position paper from the Cardiac Rehabilitation Section of the European Association of Cardiovascular Prevention and Rehabilitation

    DEFF Research Database (Denmark)

    Carré, François; Heuschmann, Peter; hoffmann, Thomas;

    2010-01-01

    , exercise training, diet/nutritional counselling, weight control management, lipid management, blood pressure monitoring, smoking cessation, and psychosocial management. Cardiac rehabilitation services are by definition multi-factorial and comprehensive, with physical activity counselling and exercise...... of a healthy lifestyle. These secondary prevention targets are included in the overall goal of cardiac rehabilitation (CR). Cardiac rehabilitation can be viewed as the clinical application of preventive care by means of a professional multi-disciplinary integrated approach for comprehensive risk reduction...... and global long-term care of cardiac patients. The CR approach is delivered in tandem with a flexible follow-up strategy and easy access to a specialized team. To promote implementation of cardiac prevention and rehabilitation, the CR Section of the EACPR (European Association of Cardiovascular Prevention...

  9. The effect of prolonged physical activity performed during extreme caloric deprivation on cardiac function.

    Directory of Open Access Journals (Sweden)

    David Planer

    Full Text Available BACKGROUND: Endurance exercise may induce transient cardiac dysfunction. Data regarding the effect of caloric restriction on cardiac function is limited. We studied the effect of physical activity performed during extreme caloric deprivation on cardiac function. METHODS: Thirty-nine healthy male soldiers (mean age 20 ± 0.3 years were studied during a field training exercise lasted 85-103 hours, with negligible food intake and unlimited water supply. Anthropometric measurements, echocardiographic examinations and blood and urine tests were performed before and after the training exercise. RESULTS: Baseline VO(2 max was 59 ± 5.5 ml/kg/min. Participants' mean weight reduction was 5.7 ± 0.9 kg. There was an increase in plasma urea (11.6 ± 2.6 to 15.8 ± 3.8 mmol/L, p<0.001 and urine osmolarity (692 ± 212 to 1094 ± 140 mmol/kg, p<0.001 and a decrease in sodium levels (140.5 ± 1.0 to 136.6 ± 2.1 mmol/L, p<0.001 at the end of the study. Significant alterations in diastolic parameters included a decrease in mitral E wave (93.6 to 83.5 cm/s; p = 0.003, without change in E/A and E/E' ratios, and an increase in iso-volumic relaxation time (73.9 to 82.9 ms, p = 0.006. There was no change in left or right ventricular systolic function, or pulmonary arterial pressure. Brain natriuretic peptide (BNP levels were significantly reduced post-training (median 9 to 0 pg/ml, p<0.001. There was no elevation in Troponin T or CRP levels. On multivariate analysis, BNP reduction correlated with sodium levels and weight reduction (R = 0.8, p<0.001. CONCLUSIONS: Exposure to prolonged physical activity performed under caloric deprivation resulted in minor alterations of left ventricular diastolic function. BNP levels were significantly reduced due to negative water and sodium balance.

  10. EFFECTS OF LONG-TERM PHYSICAL ACTIVITY ON CARDIAC STRUCTURE AND FUNCTION: A TWIN STUDY

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    Urho M.Kujala

    2009-12-01

    Full Text Available Previous studies have shown that athletic training or other physical activity causes structural and functional adaptations in the heart, but less is known how long-term physical activity affects heart when genetic liability and childhood environment are taken into account. The aim of this study was to investigate the effects of long-term physical activity vs. inactivity on cardiac structure and function in twin pairs discordant for physical activity for 32 years. Twelve same-sex twin pairs (five monozygotic and seven dizygotic, 50-67 years were studied as a part of the TWINACTIVE study. Discordance in physical activity was initially determined in 1975 and it remained significant throughout the follow-up. At the end of the follow-up in 2007, resting echocardiographic and electrocardiographic measurements were performed. During the follow-up period, the active co-twins were on average 8.2 (SD 4.0 MET hours/day more active than their inactive co-twins (p < 0.001. At the end of the follow-up, resting heart rate was lower in the active than inactive co-twins [59 (SD 5 vs. 68 (SD 10 bpm, p=0.03]. The heart rate-corrected QT interval was similar between the co-twins. Also, there was a tendency for left ventricular mass per body weight to be greater and T wave amplitude in lead II to be higher in the active co-twins (18% and 15%, respectively, p=0.08 for both. Similar trends were found for both monozygotic and dizygotic twin pairs. In conclusion, the main adaptation to long- term physical activity is lowered resting heart rate, even after partially or fully controlling for genetic liability and childhood environment

  11. Characterization of Cardiac-Resident Progenitor Cells Expressing High Aldehyde Dehydrogenase Activity

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    Marc-Estienne Roehrich

    2013-01-01

    Full Text Available High aldehyde dehydrogenase (ALDH activity has been associated with stem and progenitor cells in various tissues. Human cord blood and bone marrow ALDH-bright (ALDHbr cells have displayed angiogenic activity in preclinical studies and have been shown to be safe in clinical trials in patients with ischemic cardiovascular disease. The presence of ALDHbr cells in the heart has not been evaluated so far. We have characterized ALDHbr cells isolated from mouse hearts. One percent of nonmyocytic cells from neonatal and adult hearts were ALDHbr. ALDHvery-br cells were more frequent in neonatal hearts than adult. ALDHbr cells were more frequent in atria than ventricles. Expression of ALDH1A1 isozyme transcripts was highest in ALDHvery-br cells, intermediate in ALDHbr cells, and lowest in ALDHdim cells. ALDH1A2 expression was highest in ALDHvery-br cells, intermediate in ALDHdim cells, and lowest in ALDHbr cells. ALDH1A3 and ALDH2 expression was detectable in ALDHvery-br and ALDHbr cells, unlike ALDHdim cells, albeit at lower levels compared with ALDH1A1 and ALDH1A2. Freshly isolated ALDHbr cells were enriched for cells expressing stem cell antigen-1, CD34, CD90, CD44, and CD106. ALDHbr cells, unlike ALDHdim cells, could be grown in culture for more than 40 passages. They expressed sarcomeric α-actinin and could be differentiated along multiple mesenchymal lineages. However, the proportion of ALDHbr cells declined with cell passage. In conclusion, the cardiac-derived ALDHbr population is enriched for progenitor cells that exhibit mesenchymal progenitor-like characteristics and can be expanded in culture. The regenerative potential of cardiac-derived ALDHbr cells remains to be evaluated.

  12. The anemia of microgravity and recumbency. Role of sympathetic neural control of erythropoietin production

    Science.gov (United States)

    Robertson, David; Krantz, Sanford B.; Biaggioni, Italo

    We hypothesize that reduced sympathetic stimulation of erythropoietin production may maintain the anemia which develops in virtually all space travellers. We tested this hypothesis in a human model of reduced sympathetic activity. Thirty-three patients with the Bradbury-Eggleston syndrome were divided into three groups according to their hemoglobin (Hgb) level. Patients with low Hgb had lower upright norepinephrine and lower upright renin. Patients with anemia also had inappropriately low plasma erythropoietin levels. We administered recombinant erythropoietin (Epogen) 25-50 units/kg s.c. 3 times per week and found that the anemia seen in autonomic failure could be reversed by this treatment. These results support the hypothesis that erythropoiesis is modulated by the sympathetic nervous system and that such mechanisms may also operate in the microgravity environment where sympathetic activity is reduced.

  13. Axon guidance of sympathetic neurons to cardiomyocytes by glial cell line-derived neurotrophic factor (GDNF.

    Directory of Open Access Journals (Sweden)

    Keiko Miwa

    Full Text Available Molecular signaling of cardiac autonomic innervation is an unresolved issue. Here, we show that glial cell line-derived neurotrophic factor (GDNF promotes cardiac sympathetic innervation in vitro and in vivo. In vitro, ventricular myocytes (VMs and sympathetic neurons (SNs isolated from neonatal rat ventricles and superior cervical ganglia were cultured at a close distance. Then, morphological and functional coupling between SNs and VMs was assessed in response to GDNF (10 ng/ml or nerve growth factor (50 ng/ml. As a result, fractions of neurofilament-M-positive axons and synapsin-I-positive area over the surface of VMs were markedly increased with GDNF by 9-fold and 25-fold, respectively, compared to control without neurotrophic factors. Pre- and post-synaptic stimulation of β1-adrenergic receptors (BAR with nicotine and noradrenaline, respectively, resulted in an increase of the spontaneous beating rate of VMs co-cultured with SNs in the presence of GDNF. GDNF overexpressing VMs by adenovirus vector (AdGDNF-VMs attracted more axons from SNs compared with mock-transfected VMs. In vivo, axon outgrowth toward the denervated myocardium in adult rat hearts after cryoinjury was also enhanced significantly by adenovirus-mediated GDNF overexpression. GDNF acts as a potent chemoattractant for sympathetic innervation of ventricular myocytes, and is a promising molecular target for regulation of cardiac function in diseased hearts.

  14. Axon guidance of sympathetic neurons to cardiomyocytes by glial cell line-derived neurotrophic factor (GDNF).

    Science.gov (United States)

    Miwa, Keiko; Lee, Jong-Kook; Takagishi, Yoshiko; Opthof, Tobias; Fu, Xianming; Hirabayashi, Masumi; Watabe, Kazuhiko; Jimbo, Yasuhiko; Kodama, Itsuo; Komuro, Issei

    2013-01-01

    Molecular signaling of cardiac autonomic innervation is an unresolved issue. Here, we show that glial cell line-derived neurotrophic factor (GDNF) promotes cardiac sympathetic innervation in vitro and in vivo. In vitro, ventricular myocytes (VMs) and sympathetic neurons (SNs) isolated from neonatal rat ventricles and superior cervical ganglia were cultured at a close distance. Then, morphological and functional coupling between SNs and VMs was assessed in response to GDNF (10 ng/ml) or nerve growth factor (50 ng/ml). As a result, fractions of neurofilament-M-positive axons and synapsin-I-positive area over the surface of VMs were markedly increased with GDNF by 9-fold and 25-fold, respectively, compared to control without neurotrophic factors. Pre- and post-synaptic stimulation of β1-adrenergic receptors (BAR) with nicotine and noradrenaline, respectively, resulted in an increase of the spontaneous beating rate of VMs co-cultured with SNs in the presence of GDNF. GDNF overexpressing VMs by adenovirus vector (AdGDNF-VMs) attracted more axons from SNs compared with mock-transfected VMs. In vivo, axon outgrowth toward the denervated myocardium in adult rat hearts after cryoinjury was also enhanced significantly by adenovirus-mediated GDNF overexpression. GDNF acts as a potent chemoattractant for sympathetic innervation of ventricular myocytes, and is a promising molecular target for regulation of cardiac function in diseased hearts.

  15. Differential and Conditional Activation of PKC-Isoforms Dictates Cardiac Adaptation during Physiological to Pathological Hypertrophy

    OpenAIRE

    Shaon Naskar; Kaberi Datta; Arkadeep Mitra; Kanchan Pathak; Ritwik Datta; Trisha Bansal; Sagartirtha Sarkar

    2014-01-01

    A cardiac hypertrophy is defined as an increase in heart mass which may either be beneficial (physiological hypertrophy) or detrimental (pathological hypertrophy). This study was undertaken to establish the role of different protein kinase-C (PKC) isoforms in the regulation of cardiac adaptation during two types of cardiac hypertrophy. Phosphorylation of specific PKC-isoforms and expression of their downstream proteins were studied during physiological and pathological hypertrophy in 24 week ...

  16. Nebivolol Ameliorates Cardiac NLRP3 Inflammasome Activation in a Juvenile-Adolescent Animal Model of Diet-Induced Obesity

    Science.gov (United States)

    Xie, Qihai; Wei, Tong; Huang, Chenglin; Liu, Penghao; Sun, Mengwei; Shen, Weili; Gao, Pingjin

    2016-01-01

    NLRP3 is involved in obesity-induced cardiac remodeling and dysfunction. In this study, we evaluated whether the cardiac protective effects of nebivolol relied on attenuating NLRP3 activation in a juvenile-adolescent animal model of diet-induced obesity. Weaning male Sprague-Dawley rats were fed with either a standard chow diet (ND) or a high-fat diet (HFD) for 8 weeks. The obese rats were subsequently subdivided into three groups: 1) HFD control group; 2) HFD with low-dose nebivolol (5 mg/kg/d); 3) HFD with high-dose nebivolol (10 mg/kg/d). Treatment with nebivolol prevented HFD-induced obesity associated excess cardiac lipid accumulation as well as myocardial mitochondrial dysfunction. Nebivolol attenuated pro-inflammatory cytokines secretion and NLRP3 inflammasome activation in myocardium of obese rats. In parallel, nebivolol treatment of obese animals increased cardiac β3-AR expression, reversing the reduction of endothelial nitric oxide synthase (eNOS). In vitro, nebivolol treatment of palmitate-incubated H9C2 cells suppressed autophagy, restored mitochondrial biogenesis, leading to decreased mitochondrial reactive oxygen species (mtROS) generation, and suppressed NLRP3 inflammasome activation. Meanwhile the presence of shRNA against β3-AR or against eNOS deteriorated the protective effects of nebivolol. These data suggest the beneficial effect of nebivolol on myocardial lipotoxicity contributing to inhibiting NLRP3 inflammasome activation possibly via improved mitochondrial dysfunction. PMID:27686325

  17. Evaluation of cardiac modulation in children in response to apnea/hypopnea using the Phone Oximeter(™).

    Science.gov (United States)

    Dehkordi, Parastoo; Garde, Ainara; Karlen, Walter; Petersen, Christian L; Wensley, David; Dumont, Guy A; Mark Ansermino, J

    2016-02-01

    Individuals with sleep disordered breathing (SDB) can experience changes in automatic cardiac regulation as a result of frequent sleep fragmentation and disturbance in normal respiration and oxygenation that accompany most apnea/hypopnea events. In adults, these changes are reflected in enhanced sympathetic and reduced parasympathetic activity. In this study, we examined the autonomic cardiac regulation in children with and without SDB, through spectral and detrended fluctuation analysis (DFA) of pulse rate variability (PRV). PRV was measured from pulse-to-pulse intervals (PPIs) of the photoplethysmogram (PPG) recorded from 160 children using the Phone Oximeter(™) in the standard setting of overnight polysomnography. Spectral analysis of PRV showed the cardiac parasympathetic index (high frequency, HF) was lower (p < 0.01) and cardiac sympathetic indices (low frequency, LF and LF/HF ratio) were higher (p < 0.01) during apnea/hypopnea events for more than 95% of children with SDB. DFA showed the short- and long-range fluctuations of heart rate were more strongly correlated in children with SDB compared to children without SDB. These findings confirm that the analysis of the PPG recorded using the Phone Oximeter(™) could be the basis for a new screening tool for assessing PRV in non-clinical environment. PMID:26732019

  18. Monitoring of immune activation using biochemical changes in a porcine model of cardiac arrest

    Directory of Open Access Journals (Sweden)

    Anton Amann

    2001-01-01

    Full Text Available In animal models, immune activation is often difficult to assess because of the limited availability of specific assays to detect cytokine activities. In human monocytes/macrophages, interferon-γ induces increased production of neopterin and an enhanced activity of indoleamine 2,3-dioxygenase, which degrades tryptophan via the kynurenine pathway. Therefore, monitoring of neopterin concentrations and of tryptophan degradation can serve to detect the extent of T helper cell 1-type immune activation during cellular immune response in humans. In a porcine model of cardiac arrest, we examined the potential use of neopterin measurements and determination of the tryptophan degradation rate as a means of estimating the extent of immune activation. Urinary neopterin concentrations were measured with high-performance liquid chromatography (HPLC and radioimmunoassay (RIA (BRAHMS Diagnostica, Berlin, Germany. Serum and plasma tryptophan and kynurenine concentrations were also determined using HPLC. Serum and urine neopterin concentrations were not detectable with HPLC in these specimens, whereas RIA gave weakly (presumably false positive results. The mean serum tryptophan concentration was 39.0 Ī 6.2 μmol/l, and the mean kynurenine concentration was 0.85 Ī 0.33 μmol/l. The average kynurenine-per-tryptophan quotient in serum was 21.7Ī 8.4 nmol/μmol, and that in plasma was 20.7Ī 9.5 nmol/μmol (n = 7, which corresponds well to normal values in humans. This study provides preliminary data to support the monitoring of tryptophan degradation but not neopterin concentrations as a potential means of detecting immune activation in a porcine model. The kynurenine-per-tryptophan quotient may serve as a short-term measurement of immune activation and hence permit an estimate of the extent of immune activation.

  19. Sympathetic vasoconstrictor nerve function in alcoholic neuropathy

    DEFF Research Database (Denmark)

    Jensen, K; Andersen, K; Smith, T;

    1984-01-01

    The peripheral sympathetic vasomotor nerve function was investigated in 18 male chronic alcoholics admitted for intellectual impairment or polyneuropathy. By means of the local 133Xenon washout technique, the sympathetic veno-arteriolar axon-reflex was studied. This normally is responsible for a 50...... (18% and 48% decrease respectively). However, in three patients with moderate neuropathy, and in one patient with no signs of neuropathy, this veno-arteriolar reflex was absent, indicating dysfunction of the peripheral sympathetic adrenergic nerve fibres. The three patients also showed a lesser degree...

  20. Cardiovascular Response Patterns to Sympathetic Stimulation by Central Hypovolemia.

    Science.gov (United States)

    Bronzwaer, Anne-Sophie G T; Verbree, Jasper; Stok, Wim J; van Buchem, Mark A; Daemen, Mat J A P; van Osch, Matthias J P; van Lieshout, Johannes J

    2016-01-01

    In healthy subjects, variation in cardiovascular responses to sympathetic stimulation evoked by submaximal lower body negative pressure (LBNP) is considerable. This study addressed the question whether inter-subject variation in cardiovascular responses coincides with consistent and reproducible responses in an individual subject. In 10 healthy subjects (5 female, median age 22 years), continuous hemodynamic parameters (finger plethysmography; Nexfin, Edwards Lifesciences), and time-domain baroreflex sensitivity (BRS) were quantified during three consecutive 5-min runs of LBNP at -50 mmHg. The protocol was repeated after 1 week to establish intra-subject reproducibility. In response to LBNP, 5 subjects (3 females) showed a prominent increase in heart rate (HR; 54 ± 14%, p = 0.001) with no change in total peripheral resistance (TPR; p = 0.25) whereas the other 5 subjects (2 females) demonstrated a significant rise in TPR (7 ± 3%, p = 0.017) with a moderate increase in HR (21 ± 9%, p = 0.004). These different reflex responses coincided with differences in resting BRS (22 ± 8 vs. 11 ± 3 ms/mmHg, p = 0.049) and resting HR (57 ± 8 vs. 71 ± 12 bpm, p = 0.047) and were highly reproducible over time. In conclusion, we found distinct cardiovascular response patterns to sympathetic stimulation by LBNP in young healthy individuals. These patterns of preferential autonomic blood pressure control appeared related to resting cardiac BRS and HR and were consistent over time. PMID:27378944

  1. Role of sympathetic nervous system and neuropeptides in obesity hypertension

    OpenAIRE

    Hall, J. E.; M.W. Brands; D.A. Hildebrandt; Kuo, J.; Fitzgerald, S.

    2000-01-01

    Obesity is the most common cause of human essential hypertension in most industrialized countries. Although the precise mechanisms of obesity hypertension are not fully understood, considerable evidence suggests that excess renal sodium reabsorption and a hypertensive shift of pressure natriuresis play a major role. Sympathetic activation appears to mediate at least part of the obesity-induced sodium retention and hypertension since adrenergic blockade or renal denervation markedly attenuates...

  2. Sympathetic neural responses to mental stress during acute simulated microgravity

    OpenAIRE

    Durocher, John J.; Schwartz, Christopher E.; Carter, Jason R.

    2009-01-01

    Neural and cardiovascular responses to mental stress and acute 6° head-down tilt (HDT) were examined separately and combined. We hypothesized sympathoexcitation during mental stress, sympathoinhibition during HDT, and an additive neural interaction during combined mental stress and HDT. Muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate (HR) were recorded in 16 healthy subjects (8 men, 8 women) in the supine position during three randomized trials: 1) menta...

  3. PROJECTION NEURONS OF THE VESTIBULO-SYMPATHETIC REFLEX PATHWAY

    OpenAIRE

    Holstein, Gay R.; Friedrich, Victor L.; Martinelli, Giorgio P.

    2014-01-01

    Changes in head position and posture are detected by the vestibular system and are normally followed by rapid modifications in blood pressure. These compensatory adjustments, which allow humans to stand up without fainting, are mediated by integration of vestibular system pathways with blood pressure control centers in the ventrolateral medulla. Orthostatic hypotension can reflect altered activity of this neural circuitry. Vestibular sensory input to the vestibulo-sympathetic pathway terminat...

  4. Effects of Peroxisome Proliferator-Activated Receptor-δ Agonist on Cardiac Healing after Myocardial Infarction.

    Directory of Open Access Journals (Sweden)

    Jeong Rang Park

    Full Text Available Peroxisome proliferator-activated receptor-delta (PPAR-δ-dependent signaling is associated with rapid wound healing in the skin. Here, we investigated the therapeutic effects of PPAR-δ-agonist treatment on cardiac healing in post-myocardial infarction (MI rats. Animals were assigned to the following groups: sham-operated control group, left anterior descending coronary artery ligation (MI group, or MI with administration of the PPAR-δ agonist GW610742 group. GW610742 (1 mg/kg was administrated intraperitoneally after the operation and repeated every 3 days. Echocardiographic data showed no differences between the two groups in terms of cardiac function and remodeling until 4 weeks. However, the degrees of angiogenesis and fibrosis after MI were significantly higher in the GW610742-treated rats than in the untreated MI rats at 1 week following MI, which changes were not different at 2 weeks after MI. Naturally, PPAR-δ expression in infarcted myocardium was highest increased in 3 day after MI and then disappeared in 14 day after MI. GW610742 increased myofibroblast differentiation and transforming growth factor-beta 2 expression in the infarct zone at 7 days after MI. GW610742 also increased bone marrow-derived mesenchymal stem cell (MSC recruitment in whole myocardium, and increased serum platelet-derived growth factor B, stromal-derived factor-1 alpha, and matrix metallopeptidase 9 levels at day 3 after MI. PPAR-δ agonists treatment have the temporal effect on early fibrosis of infarcted myocardium, which might not sustain the functional and structural beneficial effect.

  5. Critical temperature ranges of hypothermia-induced platelet activation: possible implications for cooling patients in cardiac surgery.

    Science.gov (United States)

    Straub, Andreas; Breuer, Melanie; Wendel, Hans P; Peter, Karlheinz; Dietz, Klaus; Ziemer, Gerhard

    2007-04-01

    Cooling of the patient is routinely applied in cardiac surgery to protect organs against ischemia. Hypothermia induces activation of platelets, but the effects of temperatures such as used during cardiac surgery are not well described. To investigate this in an in-vitro study heparinized whole blood was incubated at different temperatures (37 degrees C, 34.5 degrees C, 32 degrees C, 29.5 degrees C, 27 degrees C, 24.5 degrees C, 22 degrees C, 19.5 degrees C and 17 degrees C). The effect of these temperatures on aggregation, P-selectin expression, GP IIb/IIIa activation and platelet microparticle (PMP) formation of unstimulated and ADP-stimulated platelets of 36 subjects was evaluated in flow cytometry. A four-parametric logistic model was fitted to depict the temperature effect on platelet parameters. Lower temperatures increased aggregates, P-selectin expression, and GP IIb/IIIa activation. The number of PMPs decreases with hypothermia. Additional experiments revealed a slight influence of heparin on platelet P-selectin expression but excluded an effect of this anticoagulant on the other evaluated parameters. Threshold temperatures, which mark 5% changes of platelet parameters compared to values at 37 degrees C, were calculated. On ADP-stimulated platelets the thresholds for P-selectin expression and GP IIb/IIa activation are 34.0 degrees C and 36.4 degrees C, respectively, and lie in the temperature range routinely applied in cardiac surgery. Hypothermia-induced platelet activation may develop in most patients undergoing cardiac surgery, possibly resulting in thromboembolic events, coagulation defects, and proinflammatory leukocyte bridging by P-selectin bearing platelets and PMPs. These findings suggest that pharmacological protection of platelets against hypothermia-induced damage may be beneficial during cardiac surgery.

  6. Singular value decomposition of optically-mapped cardiac rotors and fibrillatory activity

    Science.gov (United States)

    Rabinovitch, A.; Biton, Y.; Braunstein, D.; Friedman, M.; Aviram, I.; Yandrapalli, S.; Pandit, S. V.; Berenfeld, O.

    2015-03-01

    Our progress of understanding how cellular and structural factors contribute to arrhythmia is hampered in part because of controversies as to whether a fibrillating heart is driven by a single, several, or multiple number of sources, whether they are focal or reentrant and how to localize them. Here we demonstrate how a novel usage of the neutral singular value decomposition (SVD) method enables the extraction of the governing spatial and temporal modes of excitation from a rotor and fibrillatory waves. Those modes highlight patterns and regions of organization in the midst of the otherwise seemingly random propagating excitation waves. We apply the method to experimental models of cardiac fibrillation in rabbit hearts. We show that SVD analysis is able to enhance the classification of the heart electrical patterns into regions harboring drivers in the form of fast reentrant activity and other regions of by-standing activity. This enhancement is accomplished without any prior assumptions regarding the spatial, temporal or spectral properties of those drivers. The analysis corroborates that the dominant mode has the highest activation rate and further reveals a new feature: a transfer of modes from the driving to passive regions resulting in a partial reaction of the passive region to the driving region.

  7. Sympathetic re-innervation after heart transplantation: dual-isotope neurotransmitter scintigraphy, norepinephrine content and historical examination

    International Nuclear Information System (INIS)

    Cardiac transplantation entails surgical disruption of the sympathetic nerve fibres from their somata, resulting in sympathetic denervation. In order to investigate the occurrence of sympathetic re-innervation, neurotransmitter scintigraphy using the norepinephrine analogue iodine-123 metaiodobenzylguanidine (MIBG) was performed in 15 patients 2-69 months after transplantation. In addition, norepinephrine content and immunohistochemical reactions of antibodies to Schwann cell-associated S100 protein, to neuron-specific enolase (NSE) and to norepinephrine were examined in 34 endomyocardial biopsies of 29 patients 1-88 months after transplantation. Anterobasal 123I-MIBG uptake indicating partial sympathetic re-innervation could be shown in 40% of the scintigraphically investigated patients 37-69 months after transplantation. In immunohistochemical studies 83% of the patients investigated 1-72 Months after transplantation showed nerve fibres in their biopsies but not positive reaction to norepinephrine. Significant norepinephrine content indicating re-innervation could not be detected in any biopsy. It was concluded that in spite of the lack of norepinephrine content there seemed to be immunohistological and scintigraphic evidence of sympathetic re-innervation. An explanation for this contradictory finding may be the reduced or missing norepinephrine storage ability compared to the restored uptake ability of regenerated sympathetic nerve fibres. (orig.)

  8. Evaluation of cardiac modulation in children in response to apnea/hypopnea using the Phone Oximeter(™).

    Science.gov (United States)

    Dehkordi, Parastoo; Garde, Ainara; Karlen, Walter; Petersen, Christian L; Wensley, David; Dumont, Guy A; Mark Ansermino, J

    2016-02-01

    Individuals with sleep disordered breathing (SDB) can experience changes in automatic cardiac regulation as a result of frequent sleep fragmentation and disturbance in normal respiration and oxygenation that accompany most apnea/hypopnea events. In adults, these changes are reflected in enhanced sympathetic and reduced parasympathetic activity. In this study, we examined the autonomic cardiac regulation in children with and without SDB, through spectral and detrended fluctuation analysis (DFA) of pulse rate variability (PRV). PRV was measured from pulse-to-pulse intervals (PPIs) of the photoplethysmogram (PPG) recorded from 160 children using the Phone Oximeter(™) in the standard setting of overnight polysomnography. Spectral analysis of PRV showed the cardiac parasympathetic index (high frequency, HF) was lower (p Oximeter(™) could be the basis for a new screening tool for assessing PRV in non-clinical environment.

  9. Sympathetic re-innervation of myocardium after liver transplant in the hereditary amyloid neuropathy; Reinnervation sympathique du myocarde apres transplantation hepatique dans la neuropathie amyloide hereditaire

    Energy Technology Data Exchange (ETDEWEB)

    Delahaye, N.; Le Guludec, D. [Medecine Nucleaire, Hopital Bichat, Paris (France); Slama, M. [Cardiologie, Hopital A.Beclere, Paris (France); Guyen, C.N. [SHFJ, DSV-CEA, Orsay (France); Dinanian, S. [Cardiologie, Hopital A.Beclere, Paris (France); Merlet, P. [SHFJ, DSV-CEA, Orsay (France)

    1997-12-31

    The hereditary amyloid neuropathy (HAN) is characterized by a progressive sensory-motor poly-neuropathy and a dysautonomia with myocardium sympathetic denervation. This is established by MIBL scintigraphy and may enhance the troubles of conduction and of cardiac rhythm. The amyloid deposits are constituted of anomalous pre-albumin fabricated by liver. The hepatic transplant (HT) is the only known treatment. Four patients (GI: 39 {+-} 5 years) have been studied by MIBG scintigraphy, 2.2 {+-} 0.7 years after HT, and compared with 12 patients (GII: 39 {+-} 12 years) studied before HT. The left ventricular function, the coronary arteries and the at-rest scintigraphy with thallium were normal for all of them. The cardiac capture of MIBG, evaluated by the cardio-mediastinal activity ratio (C/M), measured on an anterior thoracic planar acquisition performed 4 hours after the intravenous injection of 300 MBq, was higher for GI than for GII (1.49 {+-} 0.12 vs 1.29 {+-} 0.13, p 0.02). The washouts (4 h / 20 min) were not different. In tomography, the patients of GI presented focal anomalies with a more-or-less extended apical defect, a satisfying fixation of the basal half of the anterior wall, more-or-less overflowing the septal and lateral walls, and for 2 patients, a satisfying inferior fixation. On the contrary, 9/12 patients of GII have had a diffuse absence of fixation, the other three heaving a satisfying antero-basal fixation ({chi}{sup 2}, p = 0.05). The results are not explained by difference of severity or evolution duration of HAN. Thus, it appears that there exists a sympathetic re-innervation of myocardium after HT in the HAN, debuting by the heart base, similarly with the effect of anatomic interruption of innervation in cardiac transplants

  10. Activation of retinoid receptor-mediated signaling ameliorates diabetes-induced cardiac dysfunction in Zucker diabetic rats.

    Science.gov (United States)

    Guleria, Rakeshwar S; Singh, Amar B; Nizamutdinova, Irina T; Souslova, Tatiana; Mohammad, Amin A; Kendall, Jonathan A; Baker, Kenneth M; Pan, Jing

    2013-04-01

    Diabetic cardiomyopathy (DCM) is a significant contributor to the morbidity and mortality associated with diabetes and metabolic syndrome. Retinoids, through activation of retinoic acid receptor (RAR) and retinoid x receptor (RXR), have been linked to control glucose and lipid homeostasis, with effects on obesity and diabetes. However, the functional role of RAR and RXR in the development of DCM remains unclear. Zucker diabetic fatty (ZDF) and lean rats were treated with Am580 (RARα agonist) or LGD1069 (RXR agonist) for 16 weeks, and cardiac function and metabolic alterations were determined. Hyperglycemia, hyperlipidemia and insulin resistance were observed in ZDF rats. Diabetic cardiomyopathy was characterized in ZDF rats by increased oxidative stress, apoptosis, fibrosis, inflammation, activation of MAP kinases and NF-κB signaling and diminished Akt phosphorylation, along with decreased glucose transport and increased cardiac lipid accumulation, and ultimately diastolic dysfunction. Am580 and LGD1069 attenuated diabetes-induced cardiac dysfunction and the pathological alterations, by improving glucose tolerance and insulin resistance; facilitating Akt activation and glucose utilization, and attenuating oxidative stress and interrelated MAP kinase and NF-κB signaling pathways. Am580 inhibited body weight gain, attenuated the increased cardiac fatty acid uptake, β-oxidation and lipid accumulation in the hearts of ZDF rats. However, LGD1069 promoted body weight gain, hyperlipidemia and cardiac lipid accumulation. In conclusion, our data suggest that activation of RAR and RXR may have therapeutic potential in the treatment of diabetic cardiomyopathy. However, further studies are necessary to clarify the role of RAR and RXR in the regulation of lipid metabolism and homeostasis.

  11. Cardiac fibroblasts contribute to myocardial dysfunction in mice with sepsis: the role of NLRP3 inflammasome activation.

    Directory of Open Access Journals (Sweden)

    Wenbo Zhang

    Full Text Available Myocardial contractile dysfunction in sepsis is associated with the increased morbidity and mortality. Although the underlying mechanisms of the cardiac depression have not been fully elucidated, an exaggerated inflammatory response is believed to be responsible. Nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3 inflammasome is an intracellular platform that is involved in the maturation and release of interleukin (IL-1β. The aim of the present study is to evaluate whether sepsis activates NLRP3 inflammasome/caspase-1/IL-1β pathway in cardiac fibroblasts (CFs and whether this cytokine can subsequently impact the function of cardiomyocytes (cardiac fibroblast-myocyte cross-talk. We show that treatment of CFs with lipopolysaccharide (LPS induces upregulation of NLRP3, activation of caspase-1, as well as the maturation (activation and release of IL-1β. In addition, the genetic (small interfering ribonucleic acid [siRNA] and pharmacological (glyburide inhibition of the NLRP3 inflammasome in CFs can block this signaling pathway. Furthermore, the inhibition of the NLRP3 inflammasome in cardiac fibroblasts ameliorated the ability of LPS-challenged CFs to impact cardiomyocyte function as assessed by intracellular cyclic adenosine monophosphate (cAMP responses in cardiomyocytes. Salient features of this the NLP3 inflammasome/ caspase-1 pathway were confirmed in in vivo models of endotoxemia/sepsis. We found that inhibition of the NLRP3 inflammasome attenuated myocardial dysfunction in mice with LPS and increased the survival rate in mice with feces-induced peritonitis. Our results indicate that the activation of the NLRP3 inflammasome in cardiac fibroblasts is pivotal in the induction of myocardial dysfunction in sepsis.

  12. Testing a longitudinal integrated self-efficacy and self-determination theory model for physical activity post-cardiac rehabilitation

    Directory of Open Access Journals (Sweden)

    Shane N. Sweet

    2014-01-01

    Full Text Available Self-determination theory and self-efficacy theory are prominent theories in the physical activity literature, and studies have begun integrating their concepts. Sweet, Fortier, Strachan and Blanchard (2012 have integrated these two theories in a cross-sectional study. Therefore, this study sought to test a longitudinal integrated model to predict physical activity at the end of a 4-month cardiac rehabilitation program based on theory, research and Sweet et al.’s cross-sectional model. Participants from two cardiac rehabilitation programs (N=109 answered validated self-report questionnaires at baseline, two and four months. Data were analyzed using Amos to assess the path analysis and model fit. Prior to integration, perceived competence and self-efficacy were combined, and labeled as confidence. After controlling for 2-month physical activity and cardiac rehabilitation site, no motivational variables significantly predicted residual change in 4-month physical activity. Although confidence at two months did not predict residual change in 4-month physical activity, it had a strong positive relationship with 2-month physical activity (β=0.30, P<0.001. The overall model retained good fit indices. In conclusion, results diverged from theoretical predictions of physical activity, but self-determination and self-efficacy theory were still partially supported. Because the model had good fit, this study demonstrated that theoretical integration is feasible.

  13. Secondary prevention through cardiac rehabilitation: physical activity counselling and exercise training: key components of the position paper from the Cardiac Rehabilitation Section of the European Association of Cardiovascular Prevention and Rehabilitation

    DEFF Research Database (Denmark)

    Corrà, Ugo; Piepoli, Massimo F; Carré, François;

    2010-01-01

    , exercise training, diet/nutritional counselling, weight control management, lipid management, blood pressure monitoring, smoking cessation, and psychosocial management. Cardiac rehabilitation services are by definition multi-factorial and comprehensive, with physical activity counselling and exercise......Cardiac patients after an acute event and/or with chronic heart disease deserve special attention to restore their quality of life and to maintain or improve functional capacity. They require counselling to avoid recurrence through a combination of adherence to a medication plan and adoption...

  14. Gender affects sympathetic neurovascular control during postural stress.

    Science.gov (United States)

    Shoemaker, J K; Hughson, R L; Sinoway, L I

    2002-07-01

    Sympathetic outflow increases during head-up tilt (HUT) to stabilize blood pressure in the presence of decreases in venous return and stroke volume (SV). Otherwise, orthostatic hypotension would develop. Gender differences in orthostatic tolerance have been noted but the mechanisms are still uncertain. More recently, Waters et al. reported in a limited sample, greater susceptibility of women to demonstrate orthostatic intolerance following space flight. Therefore, it is important to understand gender differences in reflex blood pressure regulation. Recently, we reported smaller increments in muscle sympathetic nerve activity (MSNA) in healthy women during graded HUT and a non-baroreflex cold pressor test. The purpose of this report is to examine the hypothesis that gender differences in blood pressure control during HUT are related to important variations in MSNA discharge patterns.

  15. Sympathetic Modulation of Immunity: Relevance to Disease

    OpenAIRE

    Bellinger, Denise L.; Millar, Brooke A.; Perez, Sam; Carter, Jeff; Wood, Carlo; ThyagaRajan, Srinivasan; Molinaro, Christine; Lubahn, Cheri; Lorton, Dianne

    2008-01-01

    Optimal host defense against pathogens requires cross-talk between the nervous and immune systems. This paper reviews sympathetic-immune interaction, one major communication pathway, and its importance for health and disease. Sympathetic innervation of primary and secondary immune organs is described, as well as evidence for neurotransmission with cells of the immune system as targets. Most research thus far as focused on neural-immune modulation in secondary lymphoid organs, and have reveale...

  16. Neuroaxonal dystrophy in aging human sympathetic ganglia.

    OpenAIRE

    Schmidt, R.E.; Chae, H. Y.; Parvin, C. A.; Roth, K A

    1990-01-01

    Autonomic dysfunction is an increasingly recognized problem in aging animals and man. The pathologic changes that produce autonomic dysfunction in human aging are largely unknown; however, in experimental animal models specific pathologic changes have been found in selected sympathetic ganglia. To address whether similar neuropathologic changes occur in aging humans, the authors have examined paravertebral and prevertebral sympathetic ganglia from a series of 56 adult autopsied nondiabetic pa...

  17. Cardiac regeneration by pharmacologically active microcarriers releasing growth factors and/or transporting adipose-derived stem cells

    Directory of Open Access Journals (Sweden)

    Monia Savi

    2014-01-01

    Full Text Available We tested the hypothesis that cardiac regeneration through local delivery of adipose-derived stem cells (ASCs, activation of resident cardiac stem cells via growth factors (GFs [hepatocyte growth factor (HGF and insulin-like growth factor 1 (IGF-1:GFs] or both, are improved by pharmacologically active microcarriers (PAMs interacting with cells/molecules conveyed on their surface. Rats with one-month old myocardial infarction were treated with ASCs, ASCs+PAMs, GF-releasing PAMs, ASCs+GF-releasing PAMs or vehicle. Two weeks later, hemodynamic function and inducibility of ventricular arrhythmias (VAs were assessed. Eventually, the hearts were subjected to anatomical and immunohistochemical analyses. A significant ASCs engraftment and the largest improvement in cardiac mechanics occurred in ASC+GF-releasing PAM rats which by contrast were more vulnerable to VAs. Thus, PAMs may improve cell/GF-based cardiac regeneration although caution should be paid on the electrophysiological impact of their physical interaction with the myocardium.

  18. [Features of brain oscillatory activity and cardiac defense in treatment arterial hypertensives].

    Science.gov (United States)

    Aftanas, L I; Brak, I V; Gilinskaia, O M; Pavlov, S V; Reva, N V

    2014-01-01

    Stress reactivity of the motivational system of defense can be assessed with the aid the cardiac defense response (CDR) - the reaction of the cardiovascular system to unexpected aversive unconditioned stimulus. The main objective of the study was revealing putative contribution of oscillatory systems of the brain into central pathogenic mechanisms of enhanced blood pressure (BP) stress-reactivity in naive patients with arterial hypertension (AH) of the 1st-2nd degrees (n = 17) and healthy control (n = 19) subjects. Using dynamic registration "beat-by-beat" arterial pressure, and oscillatory activity related EEG (64 channels) is estimated using the event-related synchronization/desynchronization (ERD/ERS). Along with abnormally high blood pressure in patients with hypertension background set significantly lower concentrations of serotonin blood platelets and increased tonic activation of the left hemisphere, reflected in the asymmetric reduction of delta- (2-4 Hz) and theta-1 (4-6 Hz) power in the central and parietal cortex in the hemisphere CDR of the patients are characterized by hyperactivity both short- and long-latency components of blood pressure. According to the dynamic analysis of the concomitant EEG, long-latency BP components may be accounted by, among other mechanisms, weakening of the descending ("top-down") inhibitory control, hypothetically implemented with the high-frequency EEG alpha (10-12 Hz) oscillations from the medial central-parietal cortex of both hemispheres of the brain. PMID:25464727

  19. Type III Transforming Growth Factor-β Receptor Drives Cardiac Hypertrophy Through β-Arrestin2-Dependent Activation of Calmodulin-Dependent Protein Kinase II.

    Science.gov (United States)

    Lou, Jie; Zhao, Dan; Zhang, Ling-Ling; Song, Shu-Ying; Li, Yan-Chao; Sun, Fei; Ding, Xiao-Qing; Yu, Chang-Jiang; Li, Yuan-Yuan; Liu, Mei-Tong; Dong, Chang-Jiang; Ji, Yong; Li, Hongliang; Chu, Wenfeng; Zhang, Zhi-Ren

    2016-09-01

    The role of type III transforming growth factor-β receptor (TβRIII) in the pathogenesis of heart diseases remains largely unclear. Here, we investigated the functional role and molecular mechanisms of TβRIII in the development of myocardial hypertrophy. Western blot and quantitative real time-polymerase chain reaction analyses revealed that the expression of TβRIII was significantly elevated in human cardiac hypertrophic samples. Consistently, TβRIII expression was substantially increased in transverse aortic constriction (TAC)- and isoproterenol-induced mouse cardiac hypertrophy in vivo and in isoproterenol-induced cardiomyocyte hypertrophy in vitro. Overexpression of TβRIII resulted in cardiomyocyte hypertrophy, whereas isoproterenol-induced cardiomyocyte hypertrophy was greatly attenuated by knockdown of TβRIII in vitro. Cardiac-specific transgenic expression of TβRIII independently led to cardiac hypertrophy in mice, which was further aggravated by isoproterenol and TAC treatment. Cardiac contractile function of the mice was not altered in TβRIII transgenic mice; however, TAC led to significantly decreased cardiac contractile function in TβRIII transgenic mice compared with control mice. Conversely, isoproterenol- and TAC-induced cardiac hypertrophy and TAC-induced cardiac contractile function impairment were partially reversed by suppression of TβRIII in vivo. Our data suggest that TβRIII mediates stress-induced cardiac hypertrophy through activation of Ca(2+)/calmodulin-dependent protein kinase II, which requires a physical interaction of β-arrestin2 with both TβRIII and calmodulin-dependent protein kinase II. Our findings indicate that stress-induced increase in TβRIII expression results in cardiac hypertrophy through β-arrestin2-dependent activation of calmodulin-dependent protein kinase II and that transforming growth factor-β and β-adrenergic receptor signaling are not involved in spontaneous cardiac hypertrophy in cardiac

  20. Testing a Longitudinal Integrated Self-Efficacy and Self-Determination Theory Model for Physical Activity Post-Cardiac Rehabilitation.

    Science.gov (United States)

    Sweet, Shane N; Fortier, Michelle S; Strachan, Shaelyn M; Blanchard, Chris M; Boulay, Pierre

    2014-01-13

    Self-determination theory and self-efficacy theory are prominent theories in the physical activity literature, and studies have begun integrating their concepts. Sweet, Fortier, Strachan and Blanchard (2012) have integrated these two theories in a cross-sectional study. Therefore, this study sought to test a longitudinal integrated model to predict physical activity at the end of a 4-month cardiac rehabilitation program based on theory, research and Sweet et al.'s cross-sectional model. Participants from two cardiac rehabilitation programs (N=109) answered validated self-report questionnaires at baseline, two and four months. Data were analyzed using Amos to assess the path analysis and model fit. Prior to integration, perceived competence and self-efficacy were combined, and labeled as confidence. After controlling for 2-month physical activity and cardiac rehabilitation site, no motivational variables significantly predicted residual change in 4-month physical activity. Although confidence at two months did not predict residual change in 4-month physical activity, it had a strong positive relationship with 2-month physical activity (β=0.30, Pself-determination and self-efficacy theory were still partially supported. Because the model had good fit, this study demonstrated that theoretical integration is feasible.

  1. Autophagic signaling and proteolytic enzyme activity in cardiac and skeletal muscle of spontaneously hypertensive rats following chronic aerobic exercise.

    Directory of Open Access Journals (Sweden)

    Elliott M McMillan

    Full Text Available Hypertension is a cardiovascular disease associated with deleterious effects in skeletal and cardiac muscle. Autophagy is a degradative process essential to muscle health. Acute exercise can alter autophagic signaling. Therefore, we aimed to characterize the effects of chronic endurance exercise on autophagy in skeletal and cardiac muscle of normotensive and hypertensive rats. Male Wistar Kyoto (WKY and spontaneously hypertensive rats (SHR were assigned to a sedentary condition or 6 weeks of treadmill running. White gastrocnemius (WG of hypertensive rats had higher (p<0.05 caspase-3 and proteasome activity, as well as elevated calpain activity. In addition, skeletal muscle of hypertensive animals had elevated (p<0.05 ATG7 and LC3I protein, LAMP2 mRNA, and cathepsin activity, indicative of enhanced autophagic signaling. Interestingly, chronic exercise training increased (p<0.05 Beclin-1, LC3, and p62 mRNA as well as proteasome activity, but reduced (p<0.05 Beclin-1 and ATG7 protein, as well as decreased (p<0.05 caspase-3, calpain, and cathepsin activity. Left ventricle (LV of hypertensive rats had reduced (p<0.05 AMPKα and LC3II protein, as well as elevated (p<0.05 p-AKT, p-p70S6K, LC3I and p62 protein, which collectively suggest reduced autophagic signaling. Exercise training had little effect on autophagy-related signaling factors in LV; however, exercise training increased (p<0.05 proteasome activity but reduced (p<0.05 caspase-3 and calpain activity. Our results suggest that autophagic signaling is altered in skeletal and cardiac muscle of hypertensive animals. Regular aerobic exercise can effectively alter the proteolytic environment in both cardiac and skeletal muscle, as well as influence several autophagy-related factors in skeletal muscle of normotensive and hypertensive rats.

  2. Attenuated muscle metaboreflex-induced increases in cardiac function in hypertension.

    Science.gov (United States)

    Sala-Mercado, Javier A; Spranger, Marty D; Abu-Hamdah, Rania; Kaur, Jasdeep; Coutsos, Matthew; Stayer, Douglas; Augustyniak, Robert A; O'Leary, Donal S

    2013-11-15

    Sympathoactivation may be excessive during exercise in subjects with hypertension, leading to increased susceptibility to adverse cardiovascular events, including arrhythmias, infarction, stroke, and sudden cardiac death. The muscle metaboreflex is a powerful cardiovascular reflex capable of eliciting marked increases in sympathetic activity during exercise. We used conscious, chronically instrumented dogs trained to run on a motor-driven treadmill to investigate the effects of hypertension on the mechanisms of the muscle metaboreflex. Experiments were performed before and 30.9 ± 4.2 days after induction of hypertension, which was induced via partial, unilateral renal artery occlusion. After induction of hypertension, resting mean arterial pressure was significantly elevated from 98.2 ± 2.6 to 141.9 ± 7.4 mmHg. The hypertension was caused by elevated total peripheral resistance. Although cardiac output was not significantly different at rest or during exercise after induction of hypertension, the rise in cardiac output with muscle metaboreflex activation was significantly reduced in hypertension. Metaboreflex-induced increases in left ventricular function were also depressed. These attenuated cardiac responses caused a smaller metaboreflex-induced rise in mean arterial pressure. We conclude that the ability of the muscle metaboreflex to elicit increases in cardiac function is impaired in hypertension, which may contribute to exercise intolerance.

  3. Feasibility of Home-Use Animal-Assisted Activities in Patients With Implanted Cardiac Electronic Devices

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    Peter Jirak

    2016-02-01

    Full Text Available Animal-assisted activities (AAAs are mainly carried out in institutions. The aim of this prospective pilot study was to assess the willingness of patients with cardiac implanted electronic devices (IEDs to participate in AAA. The sample included 75 ambulatory patients (18 females, M age = 69 years, who attended an outpatient clinic for control of antibradycardic pacemakers (n = 15 or implanted cardioverter defibrillators (n = 60. Twenty-three percent were current and 48% were previous pet-owners. Current pet-owners were younger than non-pet-owners (63.5 vs. 72.0 years, p = .0003. Twelve patients (16% showed interest in AAA visits. However, only two patients agreed to an AAA visit. Both patients were visited once, but declined further visits. Hence, AAA sessions at home were poorly accepted, mainly because the patients considered themselves too busy or healthy, or due to a general disinterest in AAA. Potential health benefits associated with AAA may not be feasible to investigate during home visits of AAA-teams in patients with IEDs who are healthy enough to leave their homes. For further studies concerning AAA in patients with cardiovascular diseases, we suggest focusing on institutions like rehabilitation centers or day care centers and on more severely sick, homebound patients.

  4. Exercise training improves cardiac autonomic nervous system activity in type 1 diabetic children.

    Science.gov (United States)

    Shin, Ki Ok; Moritani, Toshio; Woo, Jinhee; Jang, Ki Soeng; Bae, Ju Yong; Yoo, Jaeho; Kang, Sunghwun

    2014-01-01

    [Purpose] We investigated the effect exercise training has on cardiac autonomic nervous system (ANS) and cardiovascular risk profiles in children with type 1 diabetes mellitus (DM). [Subjects] Fifteen type 1 DM children (all boys; 13.0±1.0 years of age) were enrolled in the study. [Methods] The subjects received exercise training three times a week in a 12-week program. Each child was asked to walk on a treadmill to achieve an exercise intensity of VO2max 60%. ANS activity was measured by power spectral analysis of the electrocardiogram (ECG). Blood samples were obtained for serum lipid profiles. To evaluate Doppler-shifted Fourier pulsatility index (PI) analysis, a 5-MHz continuous wave Doppler (VASCULAB D10) set was used to measure forward blood flow velocity (FLOW) in the radial artery. [Results] Total and low-frequency (LF) power of heart rate variability increased significantly after exercise intervention. Total cholesterol (TC) levels were significant lower after exercise intervention. Total and high-frequency (HF) power were significantly correlated with higher TC levels, but diastolic blood pressure and HF was significantly correlated with lower TC levels. [Conclusion] Regular exercise intervention should be prescribed for children with type 1 DM.

  5. Update on the Pathophysiological Activities of the Cardiac Molecule Cardiotrophin-1 in Obesity

    Directory of Open Access Journals (Sweden)

    Mohamed Asrih

    2013-01-01

    Full Text Available Cardiotrophin-1 (CT-1 is a heart-targeting cytokine that has been reported to exert a variety of activities also in other organs such as the liver, adipose tissue, and atherosclerotic arteries. CT-1 has been shown to induce these effects via binding to a transmembrane receptor, comprising the leukaemia inhibitory factor receptor (LIFRβ subunit and the glycoprotein 130 (gp130, a common signal transducer. Both local and systemic concentrations of CT-1 have been shown to potentially play a critical role in obesity. For instance, CT-1 plasma concentrations have been shown to be increased in metabolic syndrome (a cluster disease including obesity probably due to adipose tissue overexpression. Interestingly, treatment with exogenous CT-1 has been shown to improve lipid and glucose metabolism in animal models of obesity. These benefits might suggest a potential therapeutic role for CT-1. However, beyond its beneficial properties, CT-1 has been also shown to induce some adverse effects, such as cardiac hypertrophy and adipose tissue inflammation. Although scientific evidence is still needed, CT-1 might be considered as a potential example of damage/danger-associated molecular pattern (DAMP in obesity-related cardiovascular diseases. In this narrative review, we aimed at discussing and updating evidence from basic research on the pathophysiological and potential therapeutic roles of CT-1 in obesity.

  6. Correlations between the signal complexity of cerebral and cardiac electrical activity: a multiscale entropy analysis.

    Science.gov (United States)

    Lin, Pei-Feng; Lo, Men-Tzung; Tsao, Jenho; Chang, Yi-Chung; Lin, Chen; Ho, Yi-Lwun

    2014-01-01

    The heart begins to beat before the brain is formed. Whether conventional hierarchical central commands sent by the brain to the heart alone explain all the interplay between these two organs should be reconsidered. Here, we demonstrate correlations between the signal complexity of brain and cardiac activity. Eighty-seven geriatric outpatients with healthy hearts and varied cognitive abilities each provided a 24-hour electrocardiography (ECG) and a 19-channel eye-closed routine electroencephalography (EEG). Multiscale entropy (MSE) analysis was applied to three epochs (resting-awake state, photic stimulation of fast frequencies (fast-PS), and photic stimulation of slow frequencies (slow-PS)) of EEG in the 1-58 Hz frequency range, and three RR interval (RRI) time series (awake-state, sleep and that concomitant with the EEG) for each subject. The low-to-high frequency power (LF/HF) ratio of RRI was calculated to represent sympatho-vagal balance. With statistics after Bonferroni corrections, we found that: (a) the summed MSE value on coarse scales of the awake RRI (scales 11-20, RRI-MSE-coarse) were inversely correlated with the summed MSE value on coarse scales of the resting-awake EEG (scales 6-20, EEG-MSE-coarse) at Fp2, C4, T6 and T4; (b) the awake RRI-MSE-coarse was inversely correlated with the fast-PS EEG-MSE-coarse at O1, O2 and C4; (c) the sleep RRI-MSE-coarse was inversely correlated with the slow-PS EEG-MSE-coarse at Fp2; (d) the RRI-MSE-coarse and LF/HF ratio of the awake RRI were correlated positively to each other; (e) the EEG-MSE-coarse at F8 was proportional to the cognitive test score; (f) the results conform to the cholinergic hypothesis which states that cognitive impairment causes reduction in vagal cardiac modulation; (g) fast-PS significantly lowered the EEG-MSE-coarse globally. Whether these heart-brain correlations could be fully explained by the central autonomic network is unknown and needs further exploration. PMID:24498375

  7. Correlations between the signal complexity of cerebral and cardiac electrical activity: a multiscale entropy analysis.

    Directory of Open Access Journals (Sweden)

    Pei-Feng Lin

    Full Text Available The heart begins to beat before the brain is formed. Whether conventional hierarchical central commands sent by the brain to the heart alone explain all the interplay between these two organs should be reconsidered. Here, we demonstrate correlations between the signal complexity of brain and cardiac activity. Eighty-seven geriatric outpatients with healthy hearts and varied cognitive abilities each provided a 24-hour electrocardiography (ECG and a 19-channel eye-closed routine electroencephalography (EEG. Multiscale entropy (MSE analysis was applied to three epochs (resting-awake state, photic stimulation of fast frequencies (fast-PS, and photic stimulation of slow frequencies (slow-PS of EEG in the 1-58 Hz frequency range, and three RR interval (RRI time series (awake-state, sleep and that concomitant with the EEG for each subject. The low-to-high frequency power (LF/HF ratio of RRI was calculated to represent sympatho-vagal balance. With statistics after Bonferroni corrections, we found that: (a the summed MSE value on coarse scales of the awake RRI (scales 11-20, RRI-MSE-coarse were inversely correlated with the summed MSE value on coarse scales of the resting-awake EEG (scales 6-20, EEG-MSE-coarse at Fp2, C4, T6 and T4; (b the awake RRI-MSE-coarse was inversely correlated with the fast-PS EEG-MSE-coarse at O1, O2 and C4; (c the sleep RRI-MSE-coarse was inversely correlated with the slow-PS EEG-MSE-coarse at Fp2; (d the RRI-MSE-coarse and LF/HF ratio of the awake RRI were correlated positively to each other; (e the EEG-MSE-coarse at F8 was proportional to the cognitive test score; (f the results conform to the cholinergic hypothesis which states that cognitive impairment causes reduction in vagal cardiac modulation; (g fast-PS significantly lowered the EEG-MSE-coarse globally. Whether these heart-brain correlations could be fully explained by the central autonomic network is unknown and needs further exploration.

  8. Propofol improves cardiac functional recovery after ischemia-reperfusion by upregulating nitric oxide synthase activity in the isolated rat hearts

    Institute of Scientific and Technical Information of China (English)

    SUN Hai-yan; XUE Fu-shan; XU Ya-chao; LI Cheng-wen; XIONG Jun; LIAO Xu; ZHANG Yan-ming

    2009-01-01

    Background There are few studies to assess whether propofol attenuates myocardial ischemia-reperfusion injury via a mechanism related to nitric oxide (NO) route, so we designed this randomized blinded experiment to observe the changes of NO contents, nitric oxide synthase (NOS) activity, NOS contents in the myocardium, and cardiac function in ischemic reperfused isolated rat hearts, and to assess the relation between myocardial NO system and cardioprotection of propofol.Methods The hearts of 30 Sprague-Dawley male rats were removed, mounted on a Langendorff apparatus, and randomly assigned to one of three groups (n=10 each group) to be treated with the following treatments in a blinded manner: Group 1, control group, after perfusion with pure Krebs Henseleit bicarbonate (K-HBB) buffer solution for 15 minutes, hearts were subjected to 20 minutes global ischemia followed by 60 minutes reperfusion with pure K-HBB buffer; Group 2, after perfusion with K-HBB buffer solution containing propofol (10 μg/ml) for 15 minutes, the hearts underwent 20 minutes global ischemia followed by 60 minutes reperfusion with the same K-HBB buffer solution; Group 3, after perfusion with K-HBB buffer solution containing propofol (10 μg/ml) and L-NAME (100 μmol/L) for 15 minutes, the hearts underwent 20 minutes global ischemia followed by 60 minutes reperfusion with the same K-HBB buffer solution. The cardiac function was continuously monitored throughout the experiment.The coronary flow was also measured. An ISO-NO electrode was placed into the right atrium close to the coronary sinus to continuously measure NO concentration in the coronary effluent. The tissue samples from apex of hearts in Groups 1 and 2 were obtained to measure the NOS activity by spectrophotometry and the NOS contents by immunohistochemistry, respectively.Results The cardiac function was significantly inhibited after ischemia and then gradually improved with reperfusion in all three groups. As compared with Group 1

  9. Assessing Physical Activity as a Core Component in Cardiac Rehabilitation: A POSITION STATEMENT OF THE AMERICAN ASSOCIATION OF CARDIOVASCULAR AND PULMONARY REHABILITATION.

    Science.gov (United States)

    Kaminsky, Leonard A; Brubaker, Peter H; Guazzi, Marco; Lavie, Carl J; Montoye, Alexander H K; Sanderson, Bonnie K; Savage, Patrick D

    2016-01-01

    Physical inactivity is a well-established major risk factor for cardiovascular disease. As such, physical activity counseling is 1 of the 10 core components of cardiac rehabilitation/secondary prevention programs recommended by the American Heart Association and the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR). In addition, the ability to perform a physical activity assessment and report outcomes is 1 of the 10 core competencies of cardiac rehabilitation/secondary prevention professionals published by the AACVPR. Unfortunately, standardized procedures for physical activity assessment of cardiac rehabilitation patients have not been developed and published. Thus, the objective of this AACVPR statement is to provide an overview of physical activity assessment concepts and procedures and to provide a recommended approach for performing a standardized assessment of physical activity in all comprehensive cardiac rehabilitation programs following the core components recommendations. PMID:27307067

  10. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008407 Effects of sympathetic nerve stimulation on connexin43 and ventricular arrhythmias during acute myocardial ischemia: experiment with rats. HU Xiaorong(胡笑容), et al. Dept Cardiol, Renmin Hosp, Wuhan Univ, Wuhan 430060. Natl Med J China 2008;88(24):1707-1710. Objective To investigate the effects of sympathetic nerve stimulation (SNS) on connexin43 (Cx43) and ventricular arrhythmias during acute myocardial ischemia (MI).

  11. Erythrocyte transketolase activity, markers of cardiac dysfunction and the diagnosis of infantile beriberi.

    Directory of Open Access Journals (Sweden)

    Douangdao Soukaloun

    Full Text Available BACKGROUND: Infantile beriberi is a potentially lethal manifestation of thiamin deficiency, associated with traditional post-partum maternal food avoidance, which persists in the Lao PDR (Laos. There are few data on biochemical markers of infantile thiamin deficiency or indices of cardiac dysfunction as potential surrogate markers. METHODOLOGY/PRINCIPAL FINDINGS: A case control study of 47 infants with beriberi and age-matched afebrile and febrile controls was conducted in Vientiane, Laos. Basal and activated erythrocyte transketolase activities (ETK and activation (α coefficients were assayed along with plasma brain natriuretic peptide, N-terminal pro-brain natriuretic peptide and troponin T. Basal ETK (and to a lesser extent activated ETK and plasma troponin T were the only infant biochemical markers that predicted infantile beriberi. A basal ETK ≤ 0.59 micromoles/min/gHb gave a sensitivity (95%CI of 75.0 (47.6 to 92.7% and specificity (95%CI of 85.2 (66.3 to 95.8% for predicting infantile beriberi (OR (95%CI 15.9 (2.03-124.2; p = 0.008 (area under ROC curve = 0.80. In contrast, the α coefficient did not discriminate between cases and controls. Maternal basal ETK was linearly correlated with infant basal ETK (Pearson's r = 0.66, p < 0.001. The odds of beriberi in infants with detectable plasma troponin T was 3.4 times higher in comparison to infants without detectable troponin T (OR 3.4, 95%CI 1.22-9.73, p = 0.019. Detectable troponin T had a sensitivity (95%CI of 78.6 (59.0 to 91.7 % and specificity (95%CI of 56.1 (39.7 to 71.5 % for predicting infantile beriberi. CONCLUSIONS/SIGNIFICANCE: Basal ETK is a more accurate biochemical marker of infantile beriberi than the activation coefficient. Raised plasma troponin T may be a useful indicator of infantile beriberi in infants at risk and in the absence of other evident causes.

  12. Secondary prevention through cardiac rehabilitation: physical activity counselling and exercise training: key components of the position paper from the Cardiac Rehabilitation Section of the European Association of Cardiovascular Prevention and Rehabilitation.

    Science.gov (United States)

    Corrà, Ugo; Piepoli, Massimo F; Carré, François; Heuschmann, Peter; Hoffmann, Uwe; Verschuren, Monique; Halcox, Julian; Giannuzzi, Pantaleo; Saner, Hugo; Wood, David; Piepoli, Massimo F; Corrà, Ugo; Benzer, Werner; Bjarnason-Wehrens, Birna; Dendale, Paul; Gaita, Dan; McGee, Hannah; Mendes, Miguel; Niebauer, Josef; Zwisler, Ann-Dorthe Olsen; Schmid, Jean-Paul

    2010-08-01

    Cardiac patients after an acute event and/or with chronic heart disease deserve special attention to restore their quality of life and to maintain or improve functional capacity. They require counselling to avoid recurrence through a combination of adherence to a medication plan and adoption of a healthy lifestyle. These secondary prevention targets are included in the overall goal of cardiac rehabilitation (CR). Cardiac rehabilitation can be viewed as the clinical application of preventive care by means of a professional multi-disciplinary integrated approach for comprehensive risk reduction and global long-term care of cardiac patients. The CR approach is delivered in tandem with a flexible follow-up strategy and easy access to a specialized team. To promote implementation of cardiac prevention and rehabilitation, the CR Section of the EACPR (European Association of Cardiovascular Prevention and Rehabilitation) has recently completed a Position Paper, entitled 'Secondary prevention through cardiac rehabilitation: A condition-oriented approach'. Components of multidisciplinary CR for seven clinical presentations have been addressed. Components include patient assessment, physical activity counselling, exercise training, diet/nutritional counselling, weight control management, lipid management, blood pressure monitoring, smoking cessation, and psychosocial management. Cardiac rehabilitation services are by definition multi-factorial and comprehensive, with physical activity counselling and exercise training as central components in all rehabilitation and preventive interventions. Many of the risk factor improvements occurring in CR can be mediated through exercise training programmes. This call-for-action paper presents the key components of a CR programme: physical activity counselling and exercise training. It summarizes current evidence-based best practice for the wide range of patient presentations of interest to the general cardiology community.

  13. Projection neurons of the vestibulo-sympathetic reflex pathway.

    Science.gov (United States)

    Holstein, Gay R; Friedrich, Victor L; Martinelli, Giorgio P

    2014-06-15

    Changes in head position and posture are detected by the vestibular system and are normally followed by rapid modifications in blood pressure. These compensatory adjustments, which allow humans to stand up without fainting, are mediated by integration of vestibular system pathways with blood pressure control centers in the ventrolateral medulla. Orthostatic hypotension can reflect altered activity of this neural circuitry. Vestibular sensory input to the vestibulo-sympathetic pathway terminates on cells in the vestibular nuclear complex, which in turn project to brainstem sites involved in the regulation of cardiovascular activity, including the rostral and caudal ventrolateral medullary regions (RVLM and CVLM, respectively). In the present study, sinusoidal galvanic vestibular stimulation was used to activate this pathway, and activated neurons were identified through detection of c-Fos protein. The retrograde tracer Fluoro-Gold was injected into the RVLM or CVLM of these animals, and immunofluorescence studies of vestibular neurons were conducted to visualize c-Fos protein and Fluoro-Gold concomitantly. We observed activated projection neurons of the vestibulo-sympathetic reflex pathway in the caudal half of the spinal, medial, and parvocellular medial vestibular nuclei. Approximately two-thirds of the cells were ipsilateral to Fluoro-Gold injection sites in both the RVLM and CVLM, and the remainder were contralateral. As a group, cells projecting to the RVLM were located slightly rostral to those with terminals in the CVLM. Individual activated projection neurons were multipolar, globular, or fusiform in shape. This study provides the first direct demonstration of the central vestibular neurons that mediate the vestibulo-sympathetic reflex. PMID:24323841

  14. Projection neurons of the vestibulo-sympathetic reflex pathway.

    Science.gov (United States)

    Holstein, Gay R; Friedrich, Victor L; Martinelli, Giorgio P

    2014-06-15

    Changes in head position and posture are detected by the vestibular system and are normally followed by rapid modifications in blood pressure. These compensatory adjustments, which allow humans to stand up without fainting, are mediated by integration of vestibular system pathways with blood pressure control centers in the ventrolateral medulla. Orthostatic hypotension can reflect altered activity of this neural circuitry. Vestibular sensory input to the vestibulo-sympathetic pathway terminates on cells in the vestibular nuclear complex, which in turn project to brainstem sites involved in the regulation of cardiovascular activity, including the rostral and caudal ventrolateral medullary regions (RVLM and CVLM, respectively). In the present study, sinusoidal galvanic vestibular stimulation was used to activate this pathway, and activated neurons were identified through detection of c-Fos protein. The retrograde tracer Fluoro-Gold was injected into the RVLM or CVLM of these animals, and immunofluorescence studies of vestibular neurons were conducted to visualize c-Fos protein and Fluoro-Gold concomitantly. We observed activated projection neurons of the vestibulo-sympathetic reflex pathway in the caudal half of the spinal, medial, and parvocellular medial vestibular nuclei. Approximately two-thirds of the cells were ipsilateral to Fluoro-Gold injection sites in both the RVLM and CVLM, and the remainder were contralateral. As a group, cells projecting to the RVLM were located slightly rostral to those with terminals in the CVLM. Individual activated projection neurons were multipolar, globular, or fusiform in shape. This study provides the first direct demonstration of the central vestibular neurons that mediate the vestibulo-sympathetic reflex.

  15. Chronic sympathetic activation promotes downregulation of ß-adrenoceptor-mediated effects in the guinea pig heart independently of structural remodeling and systolic dysfunction

    DEFF Research Database (Denmark)

    Soltysinska, Ewa; Thiele, Stefanie; Osadchiy, Oleg;

    2011-01-01

    , an activator of the adenylate cyclase catalytic subunit, were well preserved in isoproterenol-treated hearts. Downregulation of ß-adrenoceptor-mediated effects upon chronic isoproterenol infusion was associated with markedly reduced stimulatory G-protein a-subunit (G(sa)) myocardial expression levels...... of myocardial ß-adrenoceptor-mediated effects independently of structural LV remodeling and systolic failure, an effect attributed to ß-adrenoceptor uncoupling from adenylate cyclase due to reduced G(sa)-protein expression....... developed pressure increase, less shortening of LV epicardial monophasic action potential and effective refractory period, and less myocardial cyclic adenosine monophosphate elevation, in response to isoproterenol exposure, when compared to saline-treated controls. Pharmacological responses to forskolin...

  16. 5-Azacytidine Induces Cardiac Differentiation of Human Umbilical Cord-Derived Mesenchymal Stem Cells by Activating Extracellular Regulated Kinase

    Science.gov (United States)

    Qian, Qian; Qian, Hui; Zhang, Xu; Zhu, Wei; Yan, Yongmin; Ye, Shengqin; Peng, Xiujuan; Li, Wei; Xu, Zhe; Sun, Lingyun

    2012-01-01

    5-Azacytidine (5-Aza) induces differentiation of mesenchymal stem cells (MSCs) into cardiomyocytes. However, the underlying mechanisms are not well understood. Our previous work showed that 5-Aza induces human bone marrow-derived MSCs to differentiate into cardiomyocytes. Here, we demonstrated that 5-Aza induced cardiac differentiation of human umbilical cord-derived MSCs (hucMSCs) and explored the potential signaling pathway. Our results showed that hucMSCs had cardiomyocyte phenotypes after 5-Aza treatment. In addition, myogenic cells differentiated from hucMSCs were positive for mRNA and protein of desmin, β-myosin heavy chain, cardiac troponin T, A-type natriuretic peptide, and Nkx2.5. Human diploid lung fibroblasts treated with 5-Aza expressed no cardiac-specific genes. 5-Aza did not induce hucMSCs to differentiate into osteoblasts. Further study revealed that 5-Aza treatment activated extracellular signal related kinases (ERK) in hucMSCs, but protein kinase C showed no response to 5-Aza administration. U0126, a specific inhibitor of ERK, could inhibit 5-Aza-induced expression of cardiac-specific genes and proteins in hucMSCs. Increased phosphorylation of signal transducers and activators of transcription 3, and up-regulation of myocyte enhancer-binding factor-2c and myogenic differentiation antigen in 5-Aza-treated hucMSCs were also suppressed by U0126. Taken together, these results suggested that sustained activation of ERK by 5-Aza contributed to the induction of the differentiation of hucMSCs into cardiomyocytes in vitro. PMID:21476855

  17. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan

    2015-09-01

    Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  18. Optimal Cardiac Resynchronization Therapy Pacing Rate in Non-Ischemic Heart Failure Patients

    DEFF Research Database (Denmark)

    Ghotbi, Adam Ali; Sander, Mikael; Køber, Lars;

    2015-01-01

    patients with non-ischemic heart failure (NYHA class II-III) were enrolled in a randomized, double-blind, crossover trial, in which the basal pacing rate was set at DDD-60 and DDD-80 for 3 months (DDD-R for 2 patients). At baseline, 3 months and 6 months, we assessed sympathetic nerve activity...... by microneurography (MSNA), peak oxygen consumption (pVO2), N-terminal pro-brain natriuretic peptide (p-NT-proBNP), echocardiography and QoL. RESULTS: DDD-80 pacing for 3 months increased the mean heart rate from 77.3 to 86.1 (p = 0.001) and reduced sympathetic activity compared to DDD-60 (51±14 bursts/100 cardiac...... cycles vs. 64±14 bursts/100 cardiac cycles, pDDD-60 to 16.7±6 mL/min/kg during DDD-80, and p-NT-proBNP remained unchanged. The QoL score indicated that DDD-60 was better tolerated. CONCLUSION: In CRT patients with non...

  19. Central and cerebrovascular effects of leg crossing in humans with sympathetic failure

    DEFF Research Database (Denmark)

    Harms, Mark P M; Wieling, Wouter; Colier, Willy N J M;

    2010-01-01

    MCA Vmean (middle cerebral artery blood velocity; using transcranial Doppler ultrasound), frontal lobe oxygenation [O2Hb (oxyhaemoglobin)] and MAP (mean arterial pressure), CO (cardiac output) and TPR (total peripheral resistance) in six patients (aged 37-67 years; three women) and age- and gender.......12 (0.52-3.27)] in the patients compared with the controls [0.83 (-0.11 to 2.04) micromol/l]. In the control subjects, CO increased 11% (PTPR. By contrast, in the patients, CO increased 9% (PTPR increased by 13% (P... cerebral perfusion and oxygenation both in patients with sympathetic failure and in healthy subjects. However, in healthy subjects, cerebral perfusion and oxygenation were improved by a rise in CO without significant changes in TPR or MAP, whereas in patients with sympathetic failure, cerebral perfusion...

  20. Methods of estimating the state of the mechanisms of regulation of cardiac activity for girls 9-10 years of age during physical training aimed at developing endurance

    OpenAIRE

    Samokih I.I.

    2012-01-01

    Are considered indicators of regulation of cardiac activity proposed D.N. Davidenko et al. (1984). It is established age-related indicators in girls from 9 to 10 years. It is shown that in the process of double-entry physical training with the implementation of priority endurance exercise significantly improves the efficiency of regulation of cardiac activity for girls. The expediency of the lessons of physical culture directed on the priority of development endurance to improve the physical ...