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Sample records for sympathetic activity recorded

  1. Advances in sympathetic nerve recording in humans

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    Elisabeth eLambert

    2012-02-01

    Full Text Available Sympathetic nerve recording is commonly assessed by measuring the firing activity of a number of neurones. While the estimation of overall sympathetic nervous activity using this multiunit recording approach has advanced our understanding of sympathetic regulation in health and disease no information is gained regarding the underling mechanisms generating the bursts of sympathetic activity. The introduction of single-unit recording has been a major step forward, enabling the examination of specific sympathetic firing patterns in diverse clinical conditions. Disturbances in sympathetic nerve firing, including high firing probabilities, high firing rates or high incidence of multiple firing, or a combination of both, may have clinical implications with regards to the development and progression of target organ damage. Understanding the mechanisms and consequences of specific firing patterns would permit the development of therapeutic strategies targeting these nuances of sympathetic overdrive.

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

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    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.

  3. Impact of lung inflation cycle frequency on rat muscle and skin sympathetic activity recorded using suction electrodes.

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    Huang, Chunhua; Marina, Nephtali; Gilbey, Michael P

    2009-10-05

    Microneurography has been used in humans to study sympathetic activity supplying targets within skeletal muscle and skin. Comparable animal studies are relatively few, probably due to the technical demands of traditional fibre picking techniques. Here we apply a simple suction electrode technique to record cutaneous (CVC) and muscle (MVC) vasoconstrictor activities and describe and investigate the basis of the frequency dependence of lung inflation related modulation. Hindlimb MVC and CVC activities were recorded concurrently. The magnitude of MVC and CVC activities at the lung inflation cycle frequency was significantly less at 2.0 Hz than at lung inflation cycle frequencies inflation cycle frequency was increased the coherence between lung inflation cycle or BP and MVC or CVC waveforms decreased. Consistent with the hypothesis that much of the coherence between lung inflation cycle and nerve activity waveforms is secondary to oscillating baroreceptor activity attributable to BP waves, partialization with the BP waveform significantly decreased the coherence between lung inflation cycle and nerve waveforms, and there was an absence of coherence between these waveforms following sinus and aortic denervation. Our data extend findings from other laboratories and establish the value of a suction electrode technique for recording MVC and CVC activities. Furthermore, our observations describe the rates of positive pressure ventilation that avoid strong and regular gating of sympathetic activity.

  4. Baroreflex control of muscle sympathetic nerve activity after carotid body tumor resection

    NARCIS (Netherlands)

    Timmers, Henri J. L. M.; Karemaker, John M.; Wieling, Wouter; Marres, Henri A. M.; Lenders, Jacques W. M.

    2003-01-01

    Bilateral carotid body tumor resection causes a permanent attenuation of vagal baroreflex sensitivity. We retrospectively examined the effects of bilateral carotid body tumor resection on the baroreflex control of sympathetic nerve traffic. Muscle sympathetic nerve activity was recorded in 5

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

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    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.

  6. Intracranial Pressure Is a Determinant of Sympathetic Activity.

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    Schmidt, Eric A; Despas, Fabien; Pavy-Le Traon, Anne; Czosnyka, Zofia; Pickard, John D; Rahmouni, Kamal; Pathak, Atul; Senard, Jean M

    2018-01-01

    Intracranial pressure (ICP) is the pressure within the cranium . ICP rise compresses brain vessels and reduces cerebral blood delivery. Massive ICP rise leads to cerebral ischemia, but it is also known to produce hypertension, bradycardia and respiratory irregularities due to a sympatho-adrenal mechanism termed Cushing response. One still unresolved question is whether the Cushing response is a non-synaptic acute brainstem ischemic mechanism or part of a larger physiological reflex for arterial blood pressure control and homeostasis regulation. We hypothesize that changes in ICP modulates sympathetic activity. Thus, modest ICP increase and decrease were achieved in mice and patients with respectively intra-ventricular and lumbar fluid infusion. Sympathetic activity was gauged directly by microneurography, recording renal sympathetic nerve activity in mice and muscle sympathetic nerve activity in patients, and gauged indirectly in both species by heart-rate variability analysis. In mice ( n = 15), renal sympathetic activity increased from 29.9 ± 4.0 bursts.s -1 (baseline ICP 6.6 ± 0.7 mmHg) to 45.7 ± 6.4 bursts.s -1 (plateau ICP 38.6 ± 1.0 mmHg) and decreased to 34.8 ± 5.6 bursts.s -1 (post-infusion ICP 9.1 ± 0.8 mmHg). In patients ( n = 10), muscle sympathetic activity increased from 51.2 ± 2.5 bursts.min -1 (baseline ICP 8.3 ± 1.0 mmHg) to 66.7 ± 2.9 bursts.min -1 (plateau ICP 25 ± 0.3 mmHg) and decreased to 58.8 ± 2.6 bursts.min -1 (post-infusion ICP 14.8 ± 0.9 mmHg). In patients 7 mmHg ICP rise significantly increases sympathetic activity by 17%. Heart-rate variability analysis demonstrated a significant vagal withdrawal during the ICP rise, in accordance with the microneurography findings. Mice and human results are alike. We demonstrate in animal and human that ICP is a reversible determinant of efferent sympathetic outflow, even at relatively low ICP levels. ICP is a biophysical stress related to the forces within the brain. But ICP has also to be

  7. Sympathetic Responses to Central Hypovolemia: New Insights from Microneurographic Recordings

    Science.gov (United States)

    2012-04-26

    reviewed and approved by the US Army Medical Research and Materiel Command Institutional Review Board and in accor- dance with the approved protocols...C. (2007b). Sympathetic nerve activity and heart rate vari- ability during severe hemorrhagic shock in sheep.Auton. Neurosci . 136, 43–51. Billman, G...A. (2002). Syncopal attack alters the burst properties of muscle sympathetic nerve activity in humans. Auton. Neurosci . 95, 141–145. Iwase, S

  8. Functional imaging of sympathetic activation during mental stress.

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    Fechir, M; Gamer, M; Blasius, I; Bauermann, T; Breimhorst, M; Schlindwein, P; Schlereth, T; Birklein, F

    2010-04-01

    Activation of the sympathetic nervous system (SNS) is essential in adapting to environmental stressors and in maintaining homeostasis. This reaction can also turn into maladaptation, associated with a wide spectrum of stress-related diseases. Up to now, the cortical mechanisms of sympathetic activation in acute mental stress have not been sufficiently characterized. We therefore investigated cerebral activation applying functional magnetic resonance imaging (fMRI) during performance of a mental stress task with graded levels of difficulty, i.e. four versions of a Stroop task (Colour Word Interference Test, CWT) in healthy subjects. To analyze stress-associated sympathetic activation, skin conductance and heart rate were continuously recorded. The results show that sympathetic activation through mental stress is associated with distinct cerebral regions being immediately involved in task performance (visual, motor, and premotor areas). Other activated regions (right insula, dorsolateral superior frontal gyrus, cerebellar regions) are unrelated to task performance. These latter regions have previously been considered to be involved in mediating different stress responses. The results might furthermore serve as a basis for future investigations of the connection between these cortical regions in the generation of stress-related diseases. Copyright 2009 Elsevier Inc. All rights reserved.

  9. A search for activation of C-nociceptors by sympathetic fibers in complex regional pain syndrome

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    Campero, Mario; Bostock, Hugh; Baumann, Thomas K.; Ochoa, José L.

    2010-01-01

    Objective Although the term ‘reflex sympathetic dystrophy’ has been replaced by ‘complex regional pain syndrome’ (CRPS) type I, there remains a widespread presumption that the sympathetic nervous system is actively involved in mediating chronic neuropathic pain [“sympathetically maintained pain” (SMP)], even in the absence of detectable neuropathophysiology. Methods We have used microneurography to evaluate possible electrophysiological interactions in 24 patients diagnosed with CRPS I (n=13), or CRPS II (n=11) by simultaneously recording from single identified sympathetic efferent fibers and C nociceptors, while provoking sympathetic neural discharges in cutaneous nerves. Results We assessed potential effects of sympathetic activity upon 35 polymodal nociceptors and 19 mechano-insensitive nociceptors, recorded in CRPS I (26 nociceptors) and CRPS II patients (28 nociceptors). No evidence of activation of nociceptors related to sympathetic discharge was found, although nociceptors in 6 CRPS II patients exhibited unrelated spontaneous pathological nerve impulse activity. Conclusion We conclude that activation of nociceptors by sympathetic efferent discharges is not a cardinal pathogenic event in either CRPS I or CRPS II patients. Significance This study shows that sympathetic-nociceptor interactions, if they exist in patients communicating chronic neuropathic pain, must be the exception. PMID:20359942

  10. Racemic ketamine decreases muscle sympathetic activity but maintains the neural response to hypotensive challenges in humans

    NARCIS (Netherlands)

    Kienbaum, P.; Heuter, T.; Michel, M. C.; Peters, J.

    2000-01-01

    BACKGROUND: Cardiovascular stimulation and increased catecholamine plasma concentrations during ketamine anesthesia have been attributed to increased central sympathetic activity as well as catecholamine reuptake inhibition in various experimental models. However, direct recordings of efferent

  11. Mechanisms of insulin action on sympathetic nerve activity

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    Muntzel, Martin S.; Anderson, Erling A.; Johnson, Alan Kim; Mark, Allyn L.

    1996-01-01

    Insulin resistance and hyperinsulinemia may contribute to the development of arterial hypertension. Although insulin may elevate arterial pressure, in part, through activation of the sympathetic nervous system, the sites and mechanisms of insulin-induced sympathetic excitation remain uncertain. While sympathoexcitation during insulin may be mediated by the baroreflex, or by modulation of norepinephrine release from sympathetic nerve endings, it has been shown repeatedly that insulin increases sympathetic outflow by actions on the central nervous system. Previous studies employing norepinephrine turnover have suggested that insulin causes sympathoexcitation by acting in the hypothalamus. Recent experiments from our laboratory involving direct measurements of regional sympathetic nerve activity have provided further evidence that insulin acts in the central nervous system. For example, administration of insulin into the third cerebralventricle increased lumbar but not renal or adrenal sympathetic nerve activity in normotensive rats. Interestingly, this pattern of regional sympathetic nerve responses to central neural administration of insulin is similar to that seen with systemic administration of insulin. Further, lesions of the anteroventral third ventricle hypothalamic (AV3V) region abolished increases in sympathetic activity to systemic administration of insulin with euglycemic clamp, suggesting that AV3V-related structures are critical for insulin-induced elevations in sympathetic outflow.

  12. Study of sympathetic nerve activity in young Indian obese individuals

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    B Kalpana

    2013-01-01

    Full Text Available Background: Obesity is the culmination of a chronic imbalance between energy intake and energy expenditure. This energy balance can be potentially affected by the activity of autonomic nervous system (ANS. Altered sympathetic nerve function may be of importance in obesity. Objective: The present study is an attempt to pinpoint the defect (if any in the activity of sympathetic limb of the ANS in obesity, by subjecting to isometric exercise stress. Materials and Methods: A total of 81 females belonging to the age group of 18-22 years were recruited for the study. The participants were divided into two groups as normal weight and obese based on WHO guidelines for Asia Pacific region. After recording the resting blood pressure, they were subjected to isometric exercise by Handgrip dynamometer. Blood pressure was recorded again, and the difference was noted down. All recorded parameters were compared between two groups using unpaired t test. The relationship between body mass index (BMI and rise in diastolic pressure was quantified by Pearson′s correlation test. A P value less than 0.05 was considered as significant. Results: In obese, the diastolic pressure was significantly higher at rest, but showed reduced rise during handgrip test in comparison with normal weight individuals. Also, the rise in diastolic pressure exhibited a negative relation with BMI. Conclusion: The result is suggestive of impaired autonomic function at rest and reduced sympathetic activity in the group of obese when subjected to stress. This could make them more prone for future development of hypertension or other cardiovascular disorders.

  13. Three Weeks of Overload Training Increases Resting Muscle Sympathetic Activity.

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    Coates, Alexandra M; Incognito, Anthony V; Seed, Jeremy D; Doherty, Connor J; Millar, Philip J; Burr, Jamie F

    2018-05-01

    Overload training is hypothesized to alter autonomic regulation, although interpretations using indirect measures of heart rate variability are conflicting. The aim of the present study was to examine the effects of overload training on muscle sympathetic nerve activity (MSNA), a direct measure of central sympathetic outflow, in recreational endurance athletes. Measurements of heart rate variability, cardiac baroreflex sensitivity (BRS), MSNA (microneurography), and sympathetic BRS were obtained in 17 healthy triathletes and cyclists after 1 wk of reduced training (baseline) and again after 3 wk of either regular (n = 7) or overload (n = 10) training. After training, the changes (Δ) in peak power output (10 ± 10 vs -12 ± 9 W, P 0.05). Overload training increased MSNA and attenuated increases in cardiac BRS and heart rate variability observed with regular training. These results support neural adaptations after overload training and suggest that increased central sympathetic outflow may be linked with decreased exercise performance.

  14. Muscle sympathetic nerve activity is related to a surrogate marker of endothelial function in healthy individuals.

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    Yrsa Bergmann Sverrisdóttir

    Full Text Available BACKGROUND: Evidence from animal studies indicates the importance of an interaction between the sympathetic nervous system and the endothelium for cardiovascular regulation. However the interaction between these two systems remains largely unexplored in humans. The aim of this study was to investigate whether directly recorded sympathetic vasoconstrictor outflow is related to a surrogate marker of endothelial function in healthy individuals. METHODS AND RESULTS: In 10 healthy normotensive subjects (3 f/7 m, (age 37+/-11 yrs, (BMI 24+/-3 kg/m(2 direct recordings of sympathetic action potentials to the muscle vascular bed (MSNA were performed and endothelial function estimated with the Reactive Hyperaemia- Peripheral Arterial Tonometry (RH-PAT technique. Blood samples were taken and time spent on leisure-time physical activities was estimated. In all subjects the rate between resting flow and the maximum flow, the Reactive Hyperemic index (RH-PAT index, was within the normal range (1.9-3.3 and MSNA was as expected for age and gender (13-44 burst/minute. RH-PAT index was inversely related to MSNA (r = -0.8, p = 0.005. RH-PAT index and MSNA were reciprocally related to time (h/week spent on physical activity (p = 0.005 and p = 0.006 respectively and platelet concentration (PLT (p = 0.02 and p = 0.004 respectively. CONCLUSIONS: Our results show that sympathetic nerve activity is related to a surrogate marker of endothelial function in healthy normotensive individuals, indicating that sympathetic outflow may be modulated by changes in endothelial function. In this study time spent on physical activity is identified as a predictor of sympathetic nerve activity and endothelial function in a group of healthy individuals. The results are of importance in understanding mechanisms underlying sympathetic activation in conditions associated with endothelial dysfunction and emphasise the importance of a daily exercise routine for maintenance of cardiovascular

  15. Muscle sympathetic nerve activity is related to a surrogate marker of endothelial function in healthy individuals.

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    Sverrisdóttir, Yrsa Bergmann; Jansson, Linda Marie; Hägg, Ulrika; Gan, Li-Ming

    2010-02-17

    Evidence from animal studies indicates the importance of an interaction between the sympathetic nervous system and the endothelium for cardiovascular regulation. However the interaction between these two systems remains largely unexplored in humans. The aim of this study was to investigate whether directly recorded sympathetic vasoconstrictor outflow is related to a surrogate marker of endothelial function in healthy individuals. In 10 healthy normotensive subjects (3 f/7 m), (age 37+/-11 yrs), (BMI 24+/-3 kg/m(2)) direct recordings of sympathetic action potentials to the muscle vascular bed (MSNA) were performed and endothelial function estimated with the Reactive Hyperaemia- Peripheral Arterial Tonometry (RH-PAT) technique. Blood samples were taken and time spent on leisure-time physical activities was estimated. In all subjects the rate between resting flow and the maximum flow, the Reactive Hyperemic index (RH-PAT index), was within the normal range (1.9-3.3) and MSNA was as expected for age and gender (13-44 burst/minute). RH-PAT index was inversely related to MSNA (r = -0.8, p = 0.005). RH-PAT index and MSNA were reciprocally related to time (h/week) spent on physical activity (p = 0.005 and p = 0.006 respectively) and platelet concentration (PLT) (p = 0.02 and p = 0.004 respectively). Our results show that sympathetic nerve activity is related to a surrogate marker of endothelial function in healthy normotensive individuals, indicating that sympathetic outflow may be modulated by changes in endothelial function. In this study time spent on physical activity is identified as a predictor of sympathetic nerve activity and endothelial function in a group of healthy individuals. The results are of importance in understanding mechanisms underlying sympathetic activation in conditions associated with endothelial dysfunction and emphasise the importance of a daily exercise routine for maintenance of cardiovascular health.

  16. Hysteresis in the sympathetic baroreflex: role of baseline nerve activity

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    Hart, Emma C; Wallin, B Gunnar; Curry, Timothy B; Joyner, Michael J; Karlsson, Tomas; Charkoudian, Nisha

    2011-01-01

    Abstract Sympathetic baroreflex sensitivity (BRS) is greater during decreasing compared to increasing diastolic blood pressure (DBP) in young men and women. In older men and women there is no difference in sympathetic BRS to increasing and decreasing DBP. We investigated whether the sensitivity of the central nervous system to increasing and decreasing DBP is dependent upon baseline muscle sympathetic nerve activity (MSNA). We hypothesised that the difference in sympathetic BRS between falling and rising segments of DBP would be positively related to baseline MSNA in 30 young men, 21 young women, 14 older men and 14 postmenopausal women. MSNA was measured using peroneal microneurography and BRS was measured using the spontaneous baroreflex threshold technique. On average, sympathetic BRS was greater during decreasing compared to increasing DBP in young men (P 0.05). In summary, baseline MSNA plays a role in determining sympathetic BRS to falling and rising DBP in young and older men and postmenopausal women, but not in young women. This relationship is consistent with a decreased potential for sympathoexcitation in people with higher resting MSNA. Furthermore, the lack of relationship in young women suggests important contributions of sex hormones to differential responses of MSNA to falling and rising pressures. PMID:21540345

  17. Local conduction during acute myocardial infarction in rats: Interplay between central sympathetic activation and endothelin

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    Theofilos M. Kolettis, MD, PhD

    2017-04-01

    Full Text Available We investigated the effects of autonomic dysfunction and endothelin on local conduction and arrhythmogenesis during myocardial infarction. We recorded ventricular tachyarrhythmias, monophasic action potentials, and activation sequences in wild-type and ETB-deficient rats displaying high endothelin levels. Central sympathetic inputs were examined after clonidine administration. Clonidine mitigated early and delayed arrhythmogenesis in ETB-deficient and wild-type rats, respectively. The right ventricular activation delay increased in clonidine-treated ETB-deficient rats and slightly decreased in wild-type rats. The left ventricular voltage rise decreased in all groups, whereas the activation delay increased mainly in clonidine-treated ETB-deficient rats. Central sympathetic activation and endothelin modulate ischemia-induced arrhythmogenesis. Ischemia alters excitability, whereas endothelin impairs local conduction, an action partly counterbalanced by central sympathetic activity.

  18. Causes and consequences of increased sympathetic activity in renal disease

    NARCIS (Netherlands)

    Joles, JA; Koomans, HA

    Much evidence indicates increased sympathetic nervous activity (SNA) in renal disease. Renal ischemia is probably a primary event leading to increased SNA. Increased SNA often occurs in association with hypertension. However, the deleterious effect of increased SNA on the diseased kidney is not only

  19. Baroreflex control of sympathetic activity in experimental hypertension

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    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.

  20. Differentiated baroreflex modulation of sympathetic nerve activity during deep brain stimulation in humans.

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    Sverrisdóttir, Yrsa B; Green, Alexander L; Aziz, Tipu Z; Bahuri, Nor Faizal A; Hyam, Jonathan; Basnayake, Shanika D; Paterson, David J

    2014-05-01

    Targeted electric deep brain stimulation in midbrain nuclei in humans alters cardiovascular parameters, presumably by modulating autonomic and baroreflex function. Baroreflex modulation of sympathetic outflow is crucial for cardiovascular regulation and is hypothesized to occur at 2 distinct brain locations. The aim of this study was to evaluate sympathetic outflow in humans with deep brain stimulating electrodes during ON and OFF stimulation of specific midbrain nuclei known to regulate cardiovascular function. Multiunit muscle sympathetic nerve activity was recorded in 17 patients undergoing deep brain stimulation for treatment of chronic neuropathic pain (n=7) and Parkinson disease (n=10). Sympathetic outflow was recorded during ON and OFF stimulation. Arterial blood pressure, heart rate, and respiratory frequency were monitored during the recording session, and spontaneous vasomotor and cardiac baroreflex sensitivity were assessed. Head-up tilt testing was performed separately in the patients with Parkinson disease postoperatively. Stimulation of the dorsal most part of the subthalamic nucleus and ventrolateral periaqueductal gray resulted in improved vasomotor baroreflex sensitivity, decreased burst frequency and blood pressure, unchanged burst amplitude distribution, and a reduced fall in blood pressure after tilt. Stimulation of the dorsolateral periaqueductal gray resulted in a shift in burst amplitude distribution toward larger amplitudes, decreased spontaneous beat-to-beat blood pressure variability, and unchanged burst frequency, baroreflex sensitivity, and blood pressure. Our results indicate that a differentiated regulation of sympathetic outflow occurs in the subthalamic nucleus and periaqueductal gray. These results may have implications in our understanding of abnormal sympathetic discharge in cardiovascular disease and provide an opportunity for therapeutic targeting.

  1. Entrainment pattern between sympathetic and phrenic nerve activities in the Sprague-Dawley rat: hypoxia-evoked sympathetic activity during expiration.

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    Dick, Thomas E; Hsieh, Y-H; Morrison, Shaun; Coles, Sharon K; Prabhakar, Nanduri

    2004-06-01

    Sympathetic and respiratory motor activities are entrained centrally. We hypothesize that this coupling may partially underlie changes in sympathetic activity evoked by hypoxia due to activity-dependent changes in the respiratory pattern. Specifically, we tested the hypothesis that sympathetic nerve activity (SNA) expresses a short-term potentiation in activity after hypoxia similar to that expressed in phrenic nerve activity (PNA). Adult male, Sprague-Dawley (Zivic Miller) rats (n = 19) were anesthetized (Equithesin), vagotomized, paralyzed, ventilated, and pneumothoracotomized. We recorded PNA and splanchnic SNA (sSNA) and generated cycle-triggered averages (CTAs) of rectified and integrated sSNA before, during, and after exposures to hypoxia (8% O(2) and 92% N(2) for 45 s). Inspiration (I) and expiration (E) were divided in half, and the average and area of integrated sSNA were calculated and compared at the following time points: before hypoxia, at the peak breathing frequency during hypoxia, immediately before the end of hypoxia, immediately after hypoxia, and 60 s after hypoxia. In our animal model, sSNA bursts consistently followed the I-E phase transition. With hypoxia, sSNA increased in both halves of E, but preferentially in the second rather than the first half of E, and decreased in I. After hypoxia, sSNA decreased abruptly, but the coefficient of variation in respiratory modulation of sSNA was significantly less than that at baseline. The hypoxic-evoked changes in sympathetic activity and respiratory pattern resulted in sSNA in the first half of E being correlated negatively to that in the second half of E (r = -0.65, P hypoxia, the variability in the entrainment pattern had returned to baseline. The preferential recruitment of late expiratory sSNA during hypoxia results from either activation by expiratory-modulated neurons or by non-modulated neurons whose excitatory drive is not gated during late E.

  2. Attenuated baroreflex control of sympathetic nerve activity after cardiovascular deconditioning in rats

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    Moffitt, J. A.; Foley, C. M.; Schadt, J. C.; Laughlin, M. H.; Hasser, E. M.

    1998-01-01

    The effect of cardiovascular deconditioning on baroreflex control of the sympathetic nervous system was evaluated after 14 days of hindlimb unloading (HU) or the control condition. Rats were chronically instrumented with catheters and sympathetic nerve recording electrodes for measurement of mean arterial pressure (MAP) and heart rate (HR) and recording of lumbar (LSNA) or renal (RSNA) sympathetic nerve activity. Experiments were conducted 24 h after surgery, with the animals in a normal posture. Baroreflex function was assessed using a logistic function that related HR and LSNA or RSNA to MAP during infusion of phenylephrine and nitroprusside. Baroreflex influence on HR was not affected by HU. Maximum baroreflex-elicited LSNA was significantly reduced in HU rats (204 +/- 11.9 vs. 342 +/- 30.6% baseline LSNA), as was maximum reflex gain (-4.0 +/- 0.6 vs. -7.8 +/- 1.3 %LSNA/mmHg). Maximum baroreflex-elicited RSNA (259 +/- 10.8 vs. 453 +/- 28.0% baseline RSNA), minimum baroreflex-elicited RSNA (-2 +/- 2.8 vs. 13 +/- 4.5% baseline RSNA), and maximum gain (-5.8 +/- 0.5 vs. -13.6 +/- 3.1 %RSNA/mmHg) were significantly decreased in HU rats. Results demonstrate that baroreflex modulation of sympathetic nervous system activity is attenuated after cardiovascular deconditioning in rodents. Data suggest that alterations in the arterial baroreflex may contribute to orthostatic intolerance after a period of bedrest or spaceflight in humans.

  3. Adolescent sympathetic activity and salivary C-reactive protein: The effects of parental behavior.

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    Nelson, Benjamin W; Byrne, Michelle L; Simmons, Julian G; Whittle, Sarah; Schwartz, Orli S; Reynolds, Eric C; O'Brien-Simpson, Neil M; Sheeber, Lisa; Allen, Nicholas B

    2017-10-01

    This study utilized a novel multisystem approach to investigate the effect of observed parental behavior on the relationship between biological mechanisms associated with disease processes (i.e., autonomic physiology and immune response) among their adolescent children. Thirty-three adolescents (23 males), aged 11-13, and their parents participated in a laboratory session in which adolescents provided baseline measures of autonomic (sympathetic) activity, and adolescents and 1 parent participated in a laboratory based dyadic conflict resolution interaction task. This included 3 male parent/male adolescent dyads, 20 female parent/male adolescent dyads, 3 male parent/female adolescent dyads, and 7 female parent/female adolescent dyads. Approximately 3 years later, adolescents provided a salivary measure of C-Reactive Protein (sCRP) to index inflammation. Analyses revealed a positive association between sympathetic activity and sCRP, as well as a moderating role of positive parental behavior in this relationship, such that the association between sympathetic activity and sCRP was greater among adolescents whose parents displayed shorter duration of positive affect. Overall findings indicate parental behavior may influence the association between adolescent sympathetic activity and inflammatory processes. These findings have important implications for understanding the impact of psychosocial factors on biological mechanisms of disease. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Burst Activity and Heart Rhythm Modulation in the Sympathetic Outflow to the Heart

    National Research Council Canada - National Science Library

    Baselli, G

    2001-01-01

    In 13 decerebrate, artificially ventilated cats preganglionic sympathetic outflow to the heart was recorded with ECG and ventilation signal, A novel algorithm was implemented that extracts weighted...

  5. Central sympathetic activation and arrhythmogenesis during acute myocardial infarction: modulating effects of endothelin-B receptors

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    Theofilos M Kolettis

    2015-02-01

    Full Text Available Sympathetic activation during acute myocardial infarction is an important arrhythmogenic mechanism, but the role of central autonomic inputs and their modulating factors remain unclear. Using the in vivo rat-model, we examined the effects of clonidine, a centrally-acting sympatholytic agent, in the presence or absence of myocardial endothelin-B (ETB receptors. We studied wild-type (n=20 and ETB-deficient rats (n=20 after permanent coronary ligation, with or without pretreatment with clonidine. Cardiac rhythm was continuously recorded for 24 hours by implantable telemetry devices, coupled by the assessment of autonomic and heart failure indices. Sympathetic activation and arrhythmogenesis were more prominent in ETB-deficient rats during the early phase post-ligation. Clonidine improved these outcomes throughout the observation period in ETB-deficient rats, but only during the delayed phase in wild-type rats. However, this benefit was counterbalanced by atrioventricular conduction abnormalities and by higher incidence of heart failure, the latter particularly evident in ETB-deficient rats. Myocardial ETB-receptors attenuate the arrhythmogenic effects of central sympathetic activation during acute myocardial infarction. ETB-receptor deficiency potentiates the sympatholytic effects of clonidine and aggravates heart failure. The interaction between endothelin and sympathetic responses during myocardial ischemia/infarction and its impact on arrhythmogenesis and left ventricular dysfunction merit further investigation.

  6. Sympathetic nerve activity and whole body heat stress in humans.

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    Low, David A; Keller, David M; Wingo, Jonathan E; Brothers, R Matthew; Crandall, Craig G

    2011-11-01

    We and others have shown that moderate passive whole body heating (i.e., increased internal temperature ∼0.7°C) increases muscle (MSNA) and skin sympathetic nerve activity (SSNA). It is unknown, however, if MSNA and/or SSNA continue to increase with more severe passive whole body heating or whether these responses plateau following moderate heating. The aim of this investigation was to test the hypothesis that MSNA and SSNA continue to increase from a moderate to a more severe heat stress. Thirteen subjects, dressed in a water-perfused suit, underwent at least one passive heat stress that increased internal temperature ∼1.3°C, while either MSNA (n = 8) or SSNA (n = 8) was continuously recorded. Heat stress significantly increased mean skin temperature (Δ∼5°C, P heat stress (Δ core temperature 0.63 ± 0.01°C) when expressed as burst frequency (26 ± 14 to 45 ± 16 bursts/min, P = 0.001), burst incidence (39 ± 13 to 48 ± 14 bursts/100 cardiac cyles, P = 0.03), or total activity (317 ± 170 to 489 ± 150 units/min, P = 0.02) and continued to increase until the end of heat stress (burst frequency: 61 ± 15 bursts/min, P = 0.01; burst incidence: 56 ± 11 bursts/100 cardiac cyles, P = 0.04; total activity: 648 ± 158 units/min, P = 0.01) relative to the mid-heating stage. Similarly, SSNA (total activity) increased midway through the heat stress (normothermia; 1,486 ± 472 to mid heat stress 6,467 ± 5,256 units/min, P = 0.03) and continued to increase until the end of heat stress (11,217 ± 6,684 units/min, P = 0.002 vs. mid-heat stress). These results indicate that both MSNA and SSNA continue to increase as internal temperature is elevated above previously reported values.

  7. Sympathetic activity during passive heat stress in healthy aged humans.

    Science.gov (United States)

    Gagnon, Daniel; Schlader, Zachary J; Crandall, Craig G

    2015-05-01

    Cardiovascular adjustments to heat stress are attenuated in healthy aged individuals, which could contribute to their greater prevalence of heat-related illnesses and deaths during heat waves. The attenuated cardiovascular adjustments in the aged could be due to lower increases in sympathetic nerve activity during heat stress. We examined muscle sympathetic nerve activity (MSNA) and plasma catecholamine concentrations in healthy young and aged individuals during whole-body passive heat stress. The main finding of this study is that increases in MSNA and plasma catecholamine concentrations did not differ between young and aged healthy individuals during passive heating. Furthermore, the increase in these variables did not differ when a cold pressor test and lower body negative pressure were superimposed upon heating. These findings suggest that attenuated cardiovascular adjustments to heat stress in healthy aged individuals are unlikely to be related to attenuated increases in sympathetic activity. Cardiovascular adjustments during heat stress are generally attenuated in healthy aged humans, which could be due to lower increases in sympathetic activity compared to the young. We compared muscle sympathetic nerve activity (MSNA) between 11 young (Y: 28 ± 4 years) and 10 aged (A: 70 ± 5 years) subjects prior to and during passive heating. Furthermore, MSNA responses were compared when a cold pressor test (CPT) and lower body negative pressure (LBNP) were superimposed upon heating. Baseline MSNA burst frequency (Y: 15 ± 4 vs. A: 31 ± 3 bursts min(-1) , P ≤ 0.01) and burst incidence (Y: 26 ± 8 vs. A: 50 ± 7 bursts (100 cardiac cycles (CC))(-1) , P ≤ 0.01) were greater in the aged. Heat stress increased core temperature to a similar extent in both groups (Y: +1.2 ± 0.1 vs. A: +1.2 ± 0.0°C, P = 0.99). Absolute levels of MSNA remained greater in the aged during heat stress (burst frequency: Y: 47 ± 6 vs. A: 63 ± 11

  8. Sympathetic nerve activity and whole body heat stress in humans

    OpenAIRE

    Low, David A.; Keller, David M.; Wingo, Jonathan E.; Brothers, R. Matthew; Crandall, Craig G.

    2011-01-01

    We and others have shown that moderate passive whole body heating (i.e., increased internal temperature ∼0.7°C) increases muscle (MSNA) and skin sympathetic nerve activity (SSNA). It is unknown, however, if MSNA and/or SSNA continue to increase with more severe passive whole body heating or whether these responses plateau following moderate heating. The aim of this investigation was to test the hypothesis that MSNA and SSNA continue to increase from a moderate to a more severe heat stress. Th...

  9. Sympathetic nervous system and spaceflight

    Science.gov (United States)

    Cooke, William H.; Convertino, Victor A.

    2007-02-01

    Purpose: Orthostatic stability on Earth is maintained through sympathetic nerve activation sufficient to increase peripheral vascular resistance and defend against reductions of blood pressure. Orthostatic instability in astronauts upon return from space missions has been linked to blunted vascular resistance responses to standing, introducing the possibility that spaceflight alters normal function between sympathetic efferent traffic and vascular reactivity. Methods: We evaluated published results of spaceflight and relevant ground-based microgravity simulations in an effort to determine responses of the sympathetic nervous system and consequences for orthostatic stability. Results: Direct microneurographic recordings from humans in space revealed that sympathetic nerve activity is increased and preserved in the upright posture after return to Earth (STS-90). However, none of the astronauts studied during STS-90 presented with presyncope postflight, leaving unanswered the question of whether postflight orthostatic intolerance is associated with blunted sympathetic nerve responses or inadequate translation into vascular resistance. Conclusions: There is little evidence to support the concept that spaceflight induces fundamental sympathetic neuroplasticity. The available data seem to support the hypothesis that regardless of whether or not sympathetic traffic is altered during flight, astronauts return with reduced blood volumes and consequent heightened baseline sympathetic activity. Because of this, the ability to withstand an orthostatic challenge postflight is directly proportional to an astronaut's maximal sympathetic activation capacity and remaining sympathetic reserve.

  10. Cardiac-locked bursts of muscle sympathetic nerve activity are absent in familial dysautonomia

    Science.gov (United States)

    Macefield, Vaughan G; Norcliffe-Kaufmann, Lucy; Axelrod, Felicia B; Kaufmann, Horacio

    2013-01-01

    Familial dysautonomia (Riley–Day syndrome) is an hereditary sensory and autonomic neuropathy (HSAN type III), expressed at birth, that is associated with reduced pain and temperature sensibilities and absent baroreflexes, causing orthostatic hypotension as well as labile blood pressure that increases markedly during emotional excitement. Given the apparent absence of functional baroreceptor afferents, we tested the hypothesis that the normal cardiac-locked bursts of muscle sympathetic nerve activity (MSNA) are absent in patients with familial dysautonomia. Tungsten microelectrodes were inserted percutaneously into muscle or cutaneous fascicles of the common peroneal nerve in 12 patients with familial dysautonomia. Spontaneous bursts of MSNA were absent in all patients, but in five patients we found evidence of tonically firing sympathetic neurones, with no cardiac rhythmicity, that increased their spontaneous discharge during emotional arousal but not during a manoeuvre that unloads the baroreceptors. Conversely, skin sympathetic nerve activity (SSNA), recorded in four patients, appeared normal. We conclude that the loss of phasic bursts of MSNA and the loss of baroreflex modulation of muscle vasoconstrictor drive contributes to the poor control of blood pressure in familial dysautonomia, and that the increase in tonic firing of muscle vasoconstrictor neurones contributes to the increase in blood pressure during emotional excitement. PMID:23165765

  11. Impact of Non-Invasive Ventilation on Sympathetic Nerve Activity in Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Haarmann, Helge; Folle, Jan; Nguyen, Xuan Phuc; Herrmann, Peter; Heusser, Karsten; Hasenfuß, Gerd; Andreas, Stefan; Raupach, Tobias

    2017-02-01

    Chronic obstructive pulmonary disease (COPD) is associated with elevated sympathetic nerve activity, which is probably linked to an increased cardiovascular risk, and may contribute to muscle dysfunction by heightened muscle vasoconstrictor drive. We hypothesized that resistive unloading of respiratory muscles by intermittent non-invasive ventilation (NIV) reduces sympathetic tone at rest and during subsequent handgrip exercise in patients with COPD. Muscle sympathetic nerve activity (MSNA) in the peroneal nerve, heart rate, blood pressure, CO 2 , and SpO 2 were continuously recorded in 5 COPD patients with intermittent NIV and 11 control COPD patients without NIV. Static and dynamic handgrip exercises were performed before and after NIV. At baseline, heart rate-adjusted MSNA (bursts/100 heart beats) did not differ between groups. NIV did not significantly affect MSNA levels at rest. However, during handgrip exercises directly following NIV, MSNA was lower than before, which was significant for dynamic handgrip (67.00 ± 3.70 vs. 62.13 ± 4.50 bursts/100 heart beats; p = 0.035 in paired t test). In contrast, MSNA (non-significantly) increased in the control group during repeated dynamic or static handgrip. During dynamic handgrip, tCO 2 was lower after NIV than before (change by -5.04 ± 0.68 mmHg vs. -0.53 ± 0.64 in the control group; p = 0.021), while systolic and diastolic blood pressure did not change significantly. NIV reduces sympathetic activation during subsequent dynamic handgrip exercise and thereby may elicit positive effects on the cardiovascular system as well as on muscle function in patients with COPD.

  12. Baroreflex control of muscle sympathetic nerve activity: a nonpharmacological measure of baroreflex sensitivity

    OpenAIRE

    Hart, Emma C.; Joyner, Michael J.; Wallin, B. Gunnar; Karlsson, Tomas; Curry, Timothy B.; Charkoudian, Nisha

    2009-01-01

    The sensitivity of baroreflex control of sympathetic nerve activity (SNA) represents the responsiveness of SNA to changes in blood pressure. In a slightly different analysis, the baroreflex threshold measures the probability of whether a sympathetic burst will occur at a given diastolic blood pressure. We hypothesized that baroreflex threshold analysis could be used to estimate the sensitivity of the sympathetic baroreflex measured by the pharmacological modified Oxford test. We compared four...

  13. Sympathetic nervous activity in cirrhosis. A survey of plasma catecholamine studies

    DEFF Research Database (Denmark)

    Henriksen, J H; Ring-Larsen, H; Christensen, N J

    1985-01-01

    This review summarizes recent progress in the knowledge of catecholamines in cirrhosis. Compensated patients have normal plasma concentration of noradrenaline. Highly elevated plasma noradrenaline concentration in decompensated patients indicates that the sympathetic nervous system is enhanced...... in this condition. This may especially apply to the sympathetic tone in the kidney, as evaluated by regional measurements of noradrenaline overflow. Hepatic elimination of catecholamines is only slightly reduced. Activation of the sympathetic nervous system seems to play an important role in the avid sodium...

  14. Sympathetic activation and baroreflex function during intradialytic hypertensive episodes.

    Directory of Open Access Journals (Sweden)

    Dvora Rubinger

    Full Text Available BACKGROUND: The mechanisms of intradialytic increases in blood pressure are not well defined. The present study was undertaken to assess the role of autonomic nervous system activation during intradialytic hypertensive episodes. METHODOLOGY/PRINCIPAL FINDINGS: Continuous interbeat intervals (IBI and systolic blood pressure (SBP were monitored during hemodialysis in 108 chronic patients. Intradialytic hypertensive episodes defined as a period of at least 10 mmHg increase in SBP between the beginning and the end of a dialysis session or hypertension resistant to ultrafiltration occurring during or immediately after the dialysis procedure, were detected in 62 out of 113 hemodialysis sessions. SBP variability, IBI variability and baroreceptor sensitivity (BRS in the low (LF and high (HF frequency ranges were assessed using the complex demodulation technique (CDM. Intradialytic hypertensive episodes were associated with an increased (n = 45 or decreased (n = 17 heart rate. The maximal blood pressure was similar in both groups. In patients with increased heart rate the increase in blood pressure was associated with marked increases in SBP and IBI variability, with suppressed BRS indices and enhanced sympatho-vagal balance. In contrast, in those with decreased heart rate, there were no significant changes in the above parameters. End-of-dialysis blood pressure in all sessions associated with hypertensive episode was significantly higher than in those without such episodes. In logistic regression analysis, predialysis BRS in the low frequency range was found to be the main predictor of intradialytic hypertension. CONCLUSION/SIGNIFICANCE: Our data point to sympathetic overactivity with feed-forward blood pressure enhancement as an important mechanism of intradialytic hypertension in a significant proportion of patients. The triggers of increased sympathetic activity during hemodialysis remain to be determined. Intradialytic hypertensive episodes

  15. Effect of generalised sympathetic activation by cold pressor test on cerebral haemodynamics in healthy humans.

    Science.gov (United States)

    Roatta, S; Micieli, G; Bosone, D; Losano, G; Bini, R; Cavallini, A; Passatore, M

    1998-07-15

    There is no general agreement regarding several aspects of the role of the sympathetic system on cerebral haemodynamics such as extent of effectiveness, operational range and site of action. This study was planned to identify the effect of a generalised sympathetic activation on the cerebral haemodynamics in healthy humans before it is masked by secondary corrections, metabolic or myogenic in nature. A total of 35 healthy volunteers aged 20-35 underwent a 5 min lasting cold pressor test (CPT) performed on their left hand. The cerebral blood flow (CBF) velocity in the middle cerebral arteries and arterial blood pressure were recorded with transcranial Doppler sonography and with a non-invasive finger-cuff method, respectively. The ratio of arterial blood pressure to mean blood velocity (ABP/Vm) and Pulsatility Index (PI) were calculated throughout each trial. CPT induced an increase in mean ABP (range 2-54 mmHg depending on the subject) and only a slight, though significant, increase in blood velocity in the middle cerebral artery (+2.4 and +4.4% on ipsi- and contralateral side, respectively). During CPT, the ratio ABP/Vm increased and PI decreased in all subjects on both sides. These changes began simultaneously with the increase in blood pressure. The increase in ABP/Vm ratio is attributed to an increase in the cerebrovascular resistance, while the concomitant reduction in PI is interpreted as due to the reduction in the compliance of the middle cerebral artery. The results suggest that generalised increases in the sympathetic discharge, causing increases in ABP, can prevent concomitant increases in CBF by acting on both small resistance and large compliant vessels. This effect is also present when a slight increase in blood pressure occurs, which suggests a moderate increase in the sympathetic discharge, i.e. when ABP remains far below the upper limit of CBF autoregulation.

  16. Sympathetic nervous activity in cirrhosis. A survey of plasma catecholamine studies

    DEFF Research Database (Denmark)

    Henriksen, J H; Ring-Larsen, H; Christensen, N J

    1985-01-01

    in this condition. This may especially apply to the sympathetic tone in the kidney, as evaluated by regional measurements of noradrenaline overflow. Hepatic elimination of catecholamines is only slightly reduced. Activation of the sympathetic nervous system seems to play an important role in the avid sodium-water...

  17. A new function for ATP: activating cardiac sympathetic afferents during myocardial ischemia.

    Science.gov (United States)

    Fu, Liang-Wu; Longhurst, John C

    2010-12-01

    Myocardial ischemia activates cardiac sympathetic afferents leading to chest pain and reflex cardiovascular responses. Brief myocardial ischemia leads to ATP release in the interstitial space. Furthermore, exogenous ATP and α,β-methylene ATP (α,β-meATP), a P2X receptor agonist, stimulate cutaneous group III and IV sensory nerve fibers. The present study tested the hypothesis that endogenous ATP excites cardiac afferents during ischemia through activation of P2 receptors. Nerve activity of single unit cardiac sympathetic afferents was recorded from the left sympathetic chain or rami communicates (T(2)-T(5)) in anesthetized cats. Single fields of 45 afferents (conduction velocities = 0.25-4.92 m/s) were identified in the left ventricle with a stimulating electrode. Five minutes of myocardial ischemia stimulated 39 of 45 cardiac afferents (8 Aδ, 37 C fibers). Epicardial application of ATP (1-4 μmol) stimulated six ischemically sensitive cardiac afferents in a dose-dependent manner. Additionally, epicardial ATP (2 μmol), ADP (2 μmol), a P2Y agonist, and α,β-meATP (0.5 μmol) significantly activated eight other ischemically sensitive afferents. Third, pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid, a P2 receptor antagonist, abolished the responses of six afferents to epicardial ATP (2 μmol) and attenuated the ischemia-related increase in activity of seven other afferents by 37%. In the absence of P2 receptor blockade, cardiac afferents responded consistently to repeated application of ATP (n = 6) and to recurrent myocardial ischemia (n = 6). Finally, six ischemia-insensitive cardiac spinal afferents did not respond to epicardial ATP (2-4 μmol), although these afferents did respond to epicardial bradykinin. Taken together, these data indicate that, during ischemia, endogenously released ATP activates ischemia-sensitive, but not ischemia-insensitive, cardiac spinal afferents through stimulation of P2 receptors likely located on the cardiac sensory

  18. Increased sympathetic nerve activity and reduced cardiac baroreflex sensitivity in rheumatoid arthritis.

    Science.gov (United States)

    Adlan, Ahmed M; Paton, Julian F R; Lip, Gregory Y H; Kitas, George D; Fisher, James P

    2017-02-01

    Rheumatoid arthritis (RA) is a chronic inflammatory condition associated with an increased risk of cardiovascular mortality. Increased sympathetic nerve activity and reduced cardiac baroreflex sensitivity heighten cardiovascular risk, althogh whether such autonomic dysfunction is present in RA is not known. In the present study, we observed an increased sympathetic nerve activity and reduced cardiac baroreflex sensitivity in patients with RA compared to matched controls. Pain was positively correlated with sympathetic nerve activity and negatively correlated with cardiac baroreflex sensitivity. The pattern of autonomic dysfunction that we describe may help to explain the increased cardiovascular risk in RA, and raises the possibility that optimizing pain management may resolve autonomic dysfunction in RA. Rheumatoid arthritis (RA) is a chronic inflammatory condition associated with increased cardiovascular morbidity/mortality and an incompletely understood pathophysiology. In animal studies, central and blood borne inflammatory cytokines that can be elevated in RA evoke pathogenic increases in sympathetic activity and reductions in baroreflex sensitivity (BRS). We hypothesized that muscle sympathetic nerve activity (MSNA) was increased and BRS decreased in RA. MSNA, blood pressure and heart rate (HR) were recorded in age- and sex-matched RA-normotensive (n = 13), RA-hypertensive patients (RA-HTN; n = 17), normotensive (NC; n = 17) and hypertensive controls (HTN; n = 16). BRS was determined using the modified Oxford technique. Inflammation and pain were determined using serum high sensitivity C-reactive protein (hs-CRP) and a visual analogue scale (VAS), respectively. MSNA was elevated similarly in RA, RA-HTN and HTN patients (32 ± 9, 35 ± 14, 37 ± 8 bursts min -1 ) compared to NC (22 ± 9 bursts min -1 ; P = 0.004). Sympathetic BRS was similar between groups (P = 0.927), whereas cardiac BRS (cBRS) was reduced in RA, RA-HTN and HTN

  19. Relevance of Sympathetic Nervous System Activation in Obesity and Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia A. Thorp

    2015-01-01

    Full Text Available Sympathetic tone is well recognised as being implicit in cardiovascular control. It is less readily acknowledged that activation of the sympathetic nervous system is integral in energy homeostasis and can exert profound metabolic effects. Accumulating data from animal and human studies suggest that central sympathetic overactivity plays a pivotal role in the aetiology and complications of several metabolic conditions that can cluster to form the Metabolic Syndrome (MetS. Given the known augmented risk for type 2 diabetes, cardiovascular disease, and premature mortality associated with the MetS understanding the complex pathways underlying the metabolic derangements involved has become a priority. Many factors have been proposed to contribute to increased sympathetic nerve activity in metabolic abnormalities including obesity, impaired baroreflex sensitivity, hyperinsulinemia, and elevated adipokine levels. Furthermore there is mounting evidence to suggest that chronic sympathetic overactivity can potentiate two of the key metabolic alterations of the MetS, central obesity and insulin resistance. This review will discuss the regulatory role of the sympathetic nervous system in metabolic control and the proposed pathophysiology linking sympathetic overactivity to metabolic abnormalities. Pharmacological and device-based approaches that target central sympathetic drive will also be discussed as possible therapeutic options to improve metabolic control in at-risk patient cohorts.

  20. Normal sympathetic nervous system response in reflex sympathetic dystrophy.

    Science.gov (United States)

    Figuerola, María de Lourdes; Levin, Gloria; Bertotti, Alicia; Ferreiro, Jorge; Barontini, Marta

    2002-01-01

    We evaluated sympathetic nervous system activity by sympathetic skin response (SSR) recording and we further investigated sympathetic and opioid outflow indirectly in patients with features of reflex sympathetic dystrophy by measuring concentrations of plasma catecholamines (CAs) and their metabolites and plasma metenkephalin (ME), before and after corticoid treatment. Six patients were studied. Basal SSR latencies, morphologies and amplitudes were normal in five patients. In one woman, latency and amplitude were also normal but the morphology was disturbed. Basal plasma ME, CA and metabolite levels were similar in the affected and non-affected limbs and a significant increase in plasma ME concentrations was observed in both affected and non-affected limbs after two weeks of steroid treatment. Altogether these results point to an adaptive supersensitivity rather than a sympathetic hyperactivity in this syndrome; also, they indicate that the therapeutic effect of steroids adds, to their known anti-inflammatory action, a stimulatory action on the endogenous opioid system.

  1. Autonomic markers of emotional processing: skin sympathetic nerve activity in humans during exposure to emotionally-charged images

    Directory of Open Access Journals (Sweden)

    Rachael eBrown

    2012-10-01

    Full Text Available The sympathetic innervation of the skin primarily subserves thermoregulation, but the system has also been commandeered as a means of expressing emotion. While it is known that the level of skin sympathetic nerve activity (SSNA is affected by anxiety, the majority of emotional studies have utilized the galvanic skin response as a means of inferring increases in SSNA. The purpose of the present study was to characterize the changes in SSNA when showing subjects neutral or emotionally-charged images from the International Affective Picture System. Skin sympathetic nerve activity was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in ten subjects. Neutral images, positively-charged images (erotica or negatively-charged images (mutilation were presented in blocks of fifteen images of a specific type, each block lasting two minutes. Images of erotica or mutilation were presented in a quasi-random fashion, each block following a block of neutral images. Both images of erotica or images of mutilation caused significant increases in SSNA, but the increases in SSNA were greater for mutilation. The increases in SSNA were often coupled with sweat release and cutaneous vasoconstriction, however, these markers were not always consistent with the SSNA increases. We conclude that SSNA, comprising cutaneous vasoconstrictor and sudomotor activity, increases with both positively-charged and negatively-charged emotional images. Measurement of SSNA provides a more comprehensive assessment of sympathetic outflow to the skin than does the use of sweat release alone as a marker of emotional processing.

  2. 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.

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

    Science.gov (United States)

    Bode, F; Wiegand, U; 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 atrial fibrillation.
Main outcome measures—Transcardiac noradrenaline, adrenaline, and lactate gradients immediately after the shock.
Results—After internal shock, arterial noradrenaline increased from a mean (SD) of 263 (128) pg/ml at baseline to 370 (148) pg/ml (p = 0.001), while coronary sinus noradrenaline fell from 448 (292) to 363 (216) pg/ml (p = 0.01), reflecting a shift from cardiac net release to net uptake. After external shock delivery, there was a similar increase in arterial noradrenaline, from 260 (112) to 459 (200) pg/ml (p = 0.03), while coronary sinus noradrenaline remained unchanged. Systemic adrenaline increased 11-fold after external shock (p = 0.01), outlasting the threefold rise following internal shock (p = 0.001). In both groups, a negative transmyocardial adrenaline gradient at baseline decreased further, indicating enhanced myocardial uptake. Cardiac lactate production occurred after ventricular fibrillation and internal shock, but not after external cardioversion, so the neurohumoral changes resulted from the defibrillation process and not from alterations in oxidative metabolism.
Conclusions—A dc shock induces marked systemic sympathoadrenal and sympathoneuronal activation, but attenuates cardiac sympathetic activity. This might promote the transient myocardial depression observed after electrical discharge to the heart.

 Keywords: defibrillation;  autonomic cardiac function;  catecholamines;  lactate

  4. Muscle Sympathetic Nerve Activity During Intense Lower Body Negative Pressure to Presyncope in Humans

    Science.gov (United States)

    2009-08-24

    maximal LBNP tolerance. Using this approach , absolute LBNP levels corresponded well to these ranges of percentages if subjects were able to continue at... patients with spinal cord injury display spontaneous bursts of MSNA, but activity is significantly lower than that of neurologically intact patients , and is...over sympathetic neural activity, and that this reduced baroreflex sensitivity is associated with syncope . We reasoned that if sympathetic baroreflexes

  5. 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 rosacea and controls, respectively) stress was augmented in rosacea (both P 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. Copyright © 2015 the American Physiological Society.

  6. A technique for estimating activity in whole nerve trunks applied to the cervical sympathetic trunk, in the rabbit.

    Science.gov (United States)

    Hellström, F; Roatta, S; Johansson, H; Passatore, M

    1999-12-24

    The changes in sympathetic outflow may be evaluated from the amplitude of the antidromic compound action potential (ACAP) according to the collision technique described by Douglas and Ritchie (Douglas, W.W. and Ritchie J.M., A technique for recording functional activity in specific groups of medullated and non-medullated fibers in whole nerve trunks. J. Physiol., 138(1957) 19-30). This technique was revised, taking into account the depressant action exerted by antidromic stimulation on sympathetic preganglionic neurones (SPNs). Cervical sympathetic nerve (CSN) of rabbits was used as experimental model. Stimulation frequencies of 0.2-0.5 Hz were found to be sufficiently low to avoid depressant actions on CSN spontaneous activity; they were employed to test the sensitivity of the technique during different experimental manoeuvres, such as changes in pulmonary-ventilation, baroreceptor unloading and arousal stimuli. In addition a procedure was devised to calibrate the ACAP amplitude: high frequency antidromic stimulation was used to induce a complete and transient inhibition of SPNs which allows to record the ACAP maximum amplitude. ACAPs recorded in various experimental conditions can then be expressed as percentage of this value.

  7. Influence of age on respiratory modulation of muscle sympathetic nerve activity, blood pressure and baroreflex function in humans.

    Science.gov (United States)

    Shantsila, Alena; McIntyre, David B; Lip, Gregory Y H; Fadel, Paul J; Paton, Julian F R; Pickering, Anthony E; Fisher, James P

    2015-09-01

    What is the central question of this study? Does ageing influence the respiratory-related bursting of muscle sympathetic nerve activity (MSNA) and the association between the rhythmic fluctuations in MSNA and blood pressure (Traube-Hering waves) that occur with respiration? What is the main finding and its importance? Despite the age-related elevation in MSNA, the cyclical inhibition of MSNA during respiration is similar between young and older individuals. Furthermore, central respiratory-sympathetic coupling plays a role in the generation of Traube-Hering waves in both young and older humans. Healthy ageing and alterations in respiratory-sympathetic coupling have been independently linked with heightened sympathetic neural vasoconstrictor activity. We investigated how age influences the respiratory-related modulation of muscle sympathetic nerve activity (MSNA) and the association between the rhythmic fluctuations in MSNA and blood pressure that occur with respiration (Traube-Hering waves; THW). Ten young (22 ± 2 years; mean ± SD) and 10 older healthy men (58 ± 6 years) were studied while resting supine and breathing spontaneously. MSNA, blood pressure and respiration were recorded simultaneously. Resting values were ascertained and respiratory cycle-triggered averaging of MSNA and blood pressure measurements performed. The MSNA burst incidence was higher in older individuals [22.7 ± 9.2 versus 42.2 ± 13.7 bursts (100 heart beats)(-1), P respiratory-related MSNA and the magnitude of Traube-Hering waves was observed in all young (100%) and most older subjects (80%). These data suggest that the strength of the cyclical inhibition of MSNA during respiration is similar between young and older individuals; thus, alterations in respiratory-sympathetic coupling appear not to contribute to the age-related elevation in MSNA. Furthermore, central respiratory-sympathetic coupling plays a role in the generation of Traube-Hering waves in both healthy young and older

  8. Baroreflex modulation of muscle sympathetic nerve activity during cold pressor test in humans

    Science.gov (United States)

    Cui, Jian; Wilson, Thad E.; Crandall, Craig G.

    2002-01-01

    The purpose of this project was to test the hypothesis that baroreceptor modulation of muscle sympathetic nerve activity (MSNA) and heart rate is altered during the cold pressor test. Ten subjects were exposed to a cold pressor test by immersing a hand in ice water for 3 min while arterial blood pressure, heart rate, and MSNA were recorded. During the second and third minute of the cold pressor test, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative (P baroreflex modulation of MSNA is elevated without altering the sensitivity of baroreflex control of heart rate.

  9. Baroreflex modulation of muscle sympathetic nerve activity during posthandgrip muscle ischemia in humans

    Science.gov (United States)

    Cui, J.; Wilson, T. E.; Shibasaki, M.; Hodges, N. A.; Crandall, C. G.

    2001-01-01

    To identify whether muscle metaboreceptor stimulation alters baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA, beat-by-beat arterial blood pressure (Finapres), and electrocardiogram were recorded in 11 healthy subjects in the supine position. Subjects performed 2 min of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 2.5 min of posthandgrip muscle ischemia. During muscle ischemia, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative (P baroreflex modulation of MSNA is elevated by muscle metaboreceptor stimulation, whereas the sensitivity of baroreflex of modulate heart rate is unchanged during posthandgrip muscle ischemia.

  10. Superoxide anions in paraventricular nucleus modulate adipose afferent reflex and sympathetic activity in rats.

    Directory of Open Access Journals (Sweden)

    Lei Ding

    Full Text Available Adipose afferent reflex (AAR is a sympatho-excitatory reflex induced by chemical stimulation of white adipose tissue (WAT. Ionotropic glutamate receptors including NMDA receptors (NMDAR and non-NMDA receptors (non-NMDAR in paraventricular nucleus (PVN mediate the AAR. Enhanced AAR contributes to sympathetic activation and hypertension in obesity rats. This study was designed to investigate the role and mechanism of superoxide anions in PVN in modulating the AAR.Renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were recorded in anesthetized rats. AAR was evaluated by the RSNA and MAP responses to injections of capsaicin into four sites of right inguinal WAT (8.0 nmol in 8.0 µl for each site. Microinjection of polyethylene glycol-superoxide dismutase (PEG-SOD, the superoxide anion scavenger tempol or the NAD(PH oxidase inhibitor apocynin into the PVN decreased the baseline RSNA and MAP, and attenuated the AAR. Unilateral WAT injection of capsaicin increased superoxide anions in bilateral PVN, which was prevented by the WAT denervation. WAT injection of capsaicin increased superoxide anion level and NAD(PH oxidase activity in the PVN, which was abolished by the PVN pretreatment with the combined NMDAR antagonist AP5 and non-NMDAR antagonist CNQX. Microinjection of the NMDAR agonist NMDA or the non-NMDAR agonist AMPA increased superoxide anion level and NAD(PH oxidase activity in the PVN.NAD(PH oxidase-derived superoxide anions in the PVN contributes to the tonic modulation of AAR. Activation of ionotropic glutamate receptors in the PVN is involved in the AAR-induced production of superoxide anions in the PVN.

  11. Deciphering the Neural Control of Sympathetic Nerve Activity: Status Report and Directions for Future Research

    Directory of Open Access Journals (Sweden)

    Susan M. Barman

    2017-12-01

    Full Text Available Sympathetic nerve activity (SNA contributes appreciably to the control of physiological function, such that pathological alterations in SNA can lead to a variety of diseases. The goal of this review is to discuss the characteristics of SNA, briefly review the methodology that has been used to assess SNA and its control, and to describe the essential role of neurophysiological studies in conscious animals to provide additional insights into the regulation of SNA. Studies in both humans and animals have shown that SNA is rhythmic or organized into bursts whose frequency varies depending on experimental conditions and the species. These rhythms are generated by brainstem neurons, and conveyed to sympathetic preganglionic neurons through several pathways, including those emanating from the rostral ventrolateral medulla. Although rhythmic SNA is present in decerebrate animals (indicating that neurons in the brainstem and spinal cord are adequate to generate this activity, there is considerable evidence that a variety of supratentorial structures including the insular and prefrontal cortices, amygdala, and hypothalamic subnuclei provide inputs to the brainstem regions that regulate SNA. It is also known that the characteristics of SNA are altered during stress and particular behaviors such as the defense response and exercise. While it is a certainty that supratentorial structures contribute to changes in SNA during these behaviors, the neural underpinnings of the responses are yet to be established. Understanding how SNA is modified during affective responses and particular behaviors will require neurophysiological studies in awake, behaving animals, including those that entail recording activity from neurons that generate SNA. Recent studies have shown that responses of neurons in the central nervous system to most sensory inputs are context-specific. Future neurophysiological studies in conscious animals should also ascertain whether this general

  12. Carotid body (Thermoreceptors, sympathetic neural activation, and cardiometabolic disease

    Directory of Open Access Journals (Sweden)

    Rodrigo Iturriaga

    Full Text Available The carotid body (CB is the main peripheral chemoreceptor that senses the arterial PO2, PCO2 and pH. In response to hypoxemia, hypercapnia and acidosis, carotid chemosensory discharge elicits reflex respiratory, autonomic and cardiovascular adjustments. The classical construct considers the CB as the main peripheral oxygen sensor, triggering reflex physiological responses to acute hypoxemia and facilitating the ventilatory acclimation to chronic hypoxemia at high altitude. However, a growing body of experimental evidence supports the novel concept that an abnormally enhanced CB chemosensory input to the brainstem contributes to overactivation of the sympathetic nervous system, and consequent pathology. Indeed, the CB has been implicated in several diseases associated with increases in central sympathetic outflow. These include hypertension, heart failure, sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome. Indeed, ablation of the CB has been proposed for the treatment of severe and resistant hypertension in humans. In this review, we will analyze and discuss new evidence supporting an important role for the CB chemoreceptor in the progression of autonomic and cardiorespiratory alterations induced by heart failure, obstructive sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome.

  13. 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.

  14. Angiotensin-(1-7 in Paraventricular Nucleus Contributes to the Enhanced Cardiac Sympathetic Afferent Reflex and Sympathetic Activity in Chronic Heart Failure Rats

    Directory of Open Access Journals (Sweden)

    Xingsheng Ren

    2017-08-01

    Full Text Available Background/Aims: Cardiac sympathetic afferent reflex (CSAR enhancement contributes to exaggerated sympathetic activation in chronic heart failure (CHF. The current study aimed to investigate the roles of angiotensin (Ang-(1-7 in CSAR modulation and sympathetic activation and Ang-(1-7 signaling pathway in paraventricular nucleus of CHF rats. Methods: CHF was induced by coronary artery ligation. Responses of renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP to epicardial application of capsaicin were used to evaluate CSAR in rats with anesthesia. Results: Ang-(1-7 increased RSNA, MAP, CSAR activity, cAMP level, NAD(PH oxidase activity and superoxide anion level more significantly in CHF than in sham-operated rats, while Mas receptor antagonist A-779 had the opposite effects. Moreover, Ang-(1-7 augmented effects of Ang II in CHF rats. The effects of Ang-(1-7 were blocked by A-779, adenylyl cyclase inhibitor SQ22536, protein kinase A inhibitor Rp-cAMP, superoxide anion scavenger tempol and NAD(PH oxidase inhibitor apocynin. Mas and AT1 receptor protein expressions, Ang-(1-7 and Ang II levels in CHF increased. Conclusions: These results indicate that Ang-(1-7 in paraventricular nucleus enhances CSAR and sympathetic output not only by exerting its own effects but also by augmenting the effects of Ang II through Mas receptor in CHF. Endogenous Ang-(1-7/Mas receptor activity contributes to CSAR enhancement and sympathetic activation in CHF, and NAD(PH oxidase-derived superoxide anions and the cAMP-PKA signaling pathway are involved in mediating the effects of Ang-(1-7 in CHF.

  15. 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…

  16. Baroreflex control of renal sympathetic nerve activity in early heart failure assessed by the sequence method.

    Science.gov (United States)

    Lataro, Renata Maria; Silva, Luiz Eduardo Virgilio; Silva, Carlos Alberto Aguiar; Salgado, Helio Cesar; Fazan, Rubens

    2017-06-01

    The integrity of the baroreflex control of sympathetic activity in heart failure (HF) remains under debate. We proposed the use of the sequence method to assess the baroreflex control of renal sympathetic nerve activity (RSNA). The sequence method assesses the spontaneous arterial pressure (AP) fluctuations and their related changes in heart rate (or other efferent responses), providing the sensitivity and the effectiveness of the baroreflex. Effectiveness refers to the fraction of spontaneous AP changes that elicits baroreflex-mediated variations in the efferent response. Using three different approaches, we showed that the baroreflex sensitivity between AP and RSNA is not altered in early HF rats. However, the sequence method provided evidence that the effectiveness of baroreflex in changing RSNA in response to AP changes is markedly decreased in HF. The results help us better understand the baroreflex control of the sympathetic nerve activity. In heart failure (HF), the reflex control of the heart rate is known to be markedly impaired; however, the baroreceptor control of the sympathetic drive remains under debate. Applying the sequence method to a series of arterial pressure (AP) and renal sympathetic nerve activity (RSNA), we demonstrated a clear dysfunction in the baroreflex control of sympathetic activity in rats with early HF. We analysed the baroreflex control of the sympathetic drive using three different approaches: AP vs. RSNA curve, cross-spectral analysis and sequence method between AP and RSNA. The sequence method also provides the baroreflex effectiveness index (BEI), which represents the percentage of AP ramps that actually produce a reflex response. The methods were applied to control rats and rats with HF induced by myocardial infarction. None of the methods employed to assess the sympathetic baroreflex gain were able to detect any differences between the control and the HF group. However, rats with HF exhibited a lower BEI compared to the

  17. Jugular venous overflow of noradrenaline from the brain: a neurochemical indicator of cerebrovascular sympathetic nerve activity in humans

    DEFF Research Database (Denmark)

    Mitchell, D.A.; Lambert, G.; Secher, Niels H.

    2009-01-01

    A novel neurochemical method was applied for studying the activity of sympathetic nerves in the human cerebral vascular system. The aim was to investigate whether noradrenaline plasma kinetic measurements made with internal jugular venous sampling reflect cerebrovascular sympathetic activity. A d...

  18. A Hypothalamic Leptin-Glutamate Interaction in the Regulation of Sympathetic Nerve Activity

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    Hong Zheng

    2017-01-01

    Full Text Available Accumulated evidence indicates that obesity-induced type 2 diabetes (T2D is associated with enhanced sympathetic activation. The present study was conducted to investigate the role for leptin-glutamate signaling within the hypothalamus in regulating sympathetic nerve activity. In anesthetized rats, microinjections of leptin (5 ng ~ 100 ng into the arcuate nucleus (ARCN and paraventricular nucleus (PVN induced increases in renal sympathetic nerve activity (RSNA, blood pressure (BP, and heart rate (HR. Prior microinjections of NMDA receptor antagonist AP5 (16 pmol into the ARCN or PVN reduced leptin-induced increases in RSNA, BP, and HR in both ARCN and PVN. Knockdown of a leptin receptor with siRNA inhibited NMDA-induced increases in RSNA, BP, and HR in the ARCN but not in the PVN. Confocal calcium imaging in the neuronal NG108 and astrocytic C6 cells demonstrated that preincubation with leptin induced an increase in intracellular calcium green fluorescence when the cells were challenged with glutamate. In high-fat diet and low-dose streptozotocin-induced T2D rats, we found that leptin receptor and NMDA NR1 receptor expressions in the ARCN and PVN were significantly increased. In conclusion, these studies provide evidence that within the hypothalamic nuclei, leptin-glutamate signaling regulates the sympathetic activation. This may contribute to the sympathoexcitation commonly observed in obesity-related T2D.

  19. 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

  20. 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…

  1. Sex Comparisons in Muscle Sympathetic Nerve Activity and Arterial Pressure Oscillations During Progressive Central Hypovolemia

    Science.gov (United States)

    2015-01-01

    Specifically, the ‘reserve’ for autonomic responses associated with blood pressure-sympathetic nerve activity (MSNA) coherence and vasoconstrictor reserves has...134. Convertino, V. A., C. A. Rickards, and K. L. Ryan. 2012. Autonomic mechanisms associated with heart rate and vasoconstrictor reserves. Clin. Auton

  2. 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

  3. 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.

  4. Visceral afferent activation-induced changes in sympathetic nerve activity and baroreflex sensitivity.

    Science.gov (United States)

    Saleh, T M; Connell, B J; Allen, G V

    1999-06-01

    The following experiments were done to determine whether changes in baroreflex sensitivity evoked by cervical vagus nerve stimulation are due to sympathoexcitation mediated by the parabrachial nucleus. The relative contribution of cardiopulmonary and general gastric afferents within the cervical vagus nerve to the depression in baroreflex sensitivity are also investigated. Male Sprague-Dawley rats anesthetized with thiobutabarbital sodium (50 mg/kg) were instrumented to measure blood pressure and heart rate or for the continuous monitoring of renal sympathetic nerve activity. Baroreflex sensitivity was measured using bolus injections of phenylephrine. Electrical stimulation of the cervical vagus (with or without the aortic depressor nerve) or the abdominal vagus nerve produced a significant increase in renal nerve activity and a decrease in baroreflex sensitivity. Both of these effects were blocked after the microinjection of lidocaine into the parabrachial nucleus before nerve stimulation. Therefore, we conclude that an increase in the activity of cardiac, pulmonary, or general gastric afferents mediated the increased sympathetic output and decreased baroreflex sensitivity via a pathway involving the parabrachial nucleus.

  5. 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 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.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.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.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.

  6. Scintigraphic evaluation of regional myocardial sympathetic activity in patients with dilated cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Eno, Shin; Takeo, Eiichiro; Katsumoto, Masayuki; Sasaki, Satoshi; Fujii, Hideaki; Kanazawa, Ikuo [Chugoku Rosai General Hospital, Kure, Hiroshima (Japan)

    1998-09-01

    Qualitative and quantitative analyses of sympathetic activity of heart and nervous sympathetic dysfunction in myocardium were investigated by using {sup 123}I-MIBG myocardial scintigraphy. Twelve normal persons (4 males, 8 females, mean age 61.3{+-}7.4) and 13 cases of dilated cardiomyopathy (11 males, 2 females, mean age 62.5{+-}14.2) were selected. Decrease of uptake rate to myocardium of I-MIBG (delayed image) and increase of washout rate were observed. Myocardial sympathetic hyperactivity was regarded as a main reason of these phenomena. Low uptake rate to myocardium of I-MIBG (delayed image) and high washout rate were observed in the whole left ventricle, and no difference of sympathetic activity according to locus of left ventricle was found. Correlation coefficient of left ventricular end-diastolic dimension with the washout rate of I-MIBG was 0.52 (p<0.05). It was suggested that washout rate may increase with progress of disease stage. (K.H.)

  7. Sympathetic activation by the cold pressor test does not increase the muscle force generation capacity.

    Science.gov (United States)

    Roatta, Silvestro; Farina, Dario

    2011-06-01

    A positive inotropic action by the sympathetic nervous system on skeletal muscles has been observed and investigated in animal and in vitro studies. This action provided a theoretical basis for the putative ergogenic action of catecholamines and adrenergic agonists, although there is no clear evidence of this effect in humans. The aim of this study was to investigate the occurrence of inotropic effects associated to physiological sympathetic activation in healthy subjects. The muscle force capacity was investigated in the tibialis anterior (n = 9 subjects) and in the soleus (n = 9) muscles electrically stimulated with single pulses and double pulses with variable interspike interval (4-1,000 ms) and short pulse trains (frequency: 5-14 Hz) before, during, and after sympathetic activation by the cold pressor test (CPT). CPT significantly decreased by 10.4 ± 7.2 and 10.6 ± 4.4% the force produced by single and double pulse stimulation, respectively, and produced smaller decreases in the force obtained by train stimulation in the tibialis anterior, while no significant changes were observed in either type of contraction in the soleus muscle. CPT failed to induce any increase in the force capacity of the investigated muscles. The prevalent decrease in force evidenced in this study supports the concept that the weakening sympathetic action on type I fiber, already shown to occur in humans, prevails over the putative potentiating action.

  8. Contributions of central command and muscle feedback to sympathetic nerve activity in contracting human skeletal muscle

    Directory of Open Access Journals (Sweden)

    Daniel eBoulton

    2016-05-01

    Full Text Available During voluntary contractions, muscle sympathetic nerve activity (MSNA to contracting muscles increases in proportion to force but the underlying mechanisms are not clear. To shed light on these mechanisms, particularly the influences of central command and muscle afferent feedback, the present study tested the hypothesis that MSNA is greater during voluntary compared with electrically-evoked contractions. Seven male subjects performed a series of 1-minute isometric dorsiflexion contractions (left leg separated by 2-minute rest periods, alternating between voluntary and electrically-evoked contractions at similar forces (5-10 % of maximum. MSNA was recorded continuously (microneurography from the left peroneal nerve and quantified from cardiac-synchronised, negative-going spikes in the neurogram. Compared with pre-contraction values, MSNA increased by 51 ± 34 % (P 0.05. MSNA analysed at 15-s intervals revealed that this effect of voluntary contraction appeared 15-30 s after contraction onset (P < 0.01, remained elevated until the end of contraction, and disappeared within 15 s after contraction. These findings suggest that central command, and not feedback from contracting muscle, is the primary mechanism responsible for the increase in MSNA to contracting muscle. The time-course of MSNA suggests that there is a longer delay in the onset of this effect compared with its cessation after contraction.

  9. Exercise training reduces sympathetic nerve activity in heart failure patients treated with carvedilol.

    Science.gov (United States)

    Fraga, Raffael; Franco, Fábio G; Roveda, Fabiana; de Matos, Luciana N J; Braga, Ana M F W; Rondon, Maria U P B; Rotta, Daniel R; Brum, Patricia C; Barretto, Antonio C P; Middlekauff, Holly R; Negrão, Carlos E

    2007-01-01

    Evidence suggests that carvedilol decreases muscle sympathetic nerve activity (MSNA) in patients with heart failure (HF) but carvedilol fails to improve forearm vascular resistance and overall functional capacity. Exercise training in HF reduces MSNA and improves forearm vascular resistance and functional capacity. To investigate whether the beneficial effects exercise training on MSNA are maintained in the presence of carvedilol. Twenty seven HF patients, NYHA Class II-III, EF <35%, peak VO(2) <20 ml/kg/min, treated with carvedilol were randomly divided into two groups: exercise training (n=15) and untrained (n=12). MSNA was recorded by microneurography. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. The four-month training program consisted of three 60-min exercise/week on a cycloergometer. Baseline parameters were similar between groups. Exercise training reduced MSNA (-14+/-3.3 bursts/100 HB, p=0.001) and increased forearm blood flow (0.6+/-0.1 mL/min/100 g, p<0.001) in HF patients on carvedilol. In addition, exercise training improved peak VO(2) in HF patients (20+/-6%, p=0.002). MSNA, FBF and peak VO(2) were unchanged in untrained HF patients on carvedilol. Exercise training reduces MSNA in heart failure patients treated with carvedilol. In addition, the beneficial effects of exercise training on muscle blood flow and functional capacity are still realized in patients on carvedilol.

  10. 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

    2014-01-01

    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

  11. Baroreflex modulation of sympathetic nerve activity to muscle in heat-stressed humans

    Science.gov (United States)

    Cui, Jian; Wilson, Thad E.; Crandall, Craig G.

    2002-01-01

    To identify whether whole body heating alters arterial baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA and beat-by-beat arterial blood pressure were recorded in seven healthy subjects during acute hypotensive and hypertensive stimuli in both normothermic and heat stress conditions. Whole body heating significantly increased sublingual temperature (P 0.05). During both normothermic and heat stress conditions, MSNA increased and then decreased significantly when blood pressure was lowered and then raised via intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure during heat stress (-128.3 +/- 13.9 U x beats(-1) x mmHg(-1)) was similar (P = 0.31) with normothermia (-140.6 +/- 21.1 U x beats(-1) x mmHg(-1)). Moreover, no significant change in the slope of the relationship between heart rate and systolic blood pressure was observed. These data suggest that arterial baroreflex modulation of MSNA and heart rate are not altered by whole body heating, with the exception of an upward shift of these baroreflex curves to accommodate changes in these variables that occur with whole body heating.

  12. Catheter-Based Renal Nerve Ablation and Centrally Generated Sympathetic Activity in Difficult-to-Control Hypertensive Patients: Prospective Case Series

    NARCIS (Netherlands)

    Brinkmann, J.; Heusser, K.; Schmidt, B.M.; Menne, J.; Klein, G.; Bauersachs, J.; Haller, H.; Sweep, F.C.; Diedrich, A.; Jordan, J.; Tank, J.

    2012-01-01

    Endovascular renal nerve ablation has been developed to treat resistant hypertension. In addition to lowering efferent renal sympathetic activation, the intervention may attenuate central sympathetic outflow through decreased renal afferent nerve traffic, as evidenced by a recent case report. We

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

    OpenAIRE

    Ohtani, Nobuyo; Okamoto, Yuta; Tateishi, Kanako; Uchiyama, Hidehiko; Ohta, Mitsuaki

    2015-01-01

    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 ...

  14. Insulin acts in the arcuate nucleus to increase lumbar sympathetic nerve activity and baroreflex function in rats

    Science.gov (United States)

    Cassaglia, Priscila A; Hermes, Sam M; Aicher, Sue A; Brooks, Virginia L

    2011-01-01

    Abstract Although the central effects of insulin to activate the sympathetic nervous system and enhance baroreflex gain are well known, the specific brain site(s) at which insulin acts has not been identified. We tested the hypotheses that (1) the paraventricular nucleus of the hypothalamus (PVN) and the arcuate nucleus (ArcN) are necessary brain sites and (2) insulin initiates its effects directly in the PVN and/or the ArcN. In α-chloralose anaesthetised female Sprague–Dawley rats, mean arterial pressure (MAP), heart rate (HR) and lumbar sympathetic nerve activity (LSNA) were recorded continuously, and baroreflex gain of HR and LSNA were measured before and during a hyperinsulinaemic–euglycaemic clamp. After 60 min, intravenous infusion of insulin (15 mU kg−1 min−1), but not saline, significantly increased (P baroreflex control of LSNA (from 3.8 ± 1.1 to 7.4 ± 2.4% control mmHg−1). These effects were reversed (P baroreflex gain (in % control mmHg−1 from 4.3 ± 1.2 to 6.9 ± 1.0, 0.6 nU; 7.7 ± 1.2, 6 nU; and 7.8 ± 1.3, 60 nU). None of the treatments altered MAP, HR, or baroreflex control of HR. Our findings identify the ArcN as the site at which insulin acts to activate the sympathetic nervous system and increase baroreflex gain, via a neural pathway that includes the PVN. PMID:21300750

  15. Carotid baroreflex regulation of sympathetic nerve activity during dynamic exercise in humans

    Science.gov (United States)

    Fadel, P. J.; Ogoh, S.; Watenpaugh, D. E.; Wasmund, W.; Olivencia-Yurvati, A.; Smith, M. L.; Raven, P. B.

    2001-01-01

    We sought to determine whether carotid baroreflex (CBR) control of muscle sympathetic nerve activity (MSNA) was altered during dynamic exercise. In five men and three women, 23.8 +/- 0.7 (SE) yr of age, CBR function was evaluated at rest and during 20 min of arm cycling at 50% peak O(2) uptake using 5-s periods of neck pressure and neck suction. From rest to steady-state arm cycling, mean arterial pressure (MAP) was significantly increased from 90.0 +/- 2.7 to 118.7 +/- 3.6 mmHg and MSNA burst frequency (microneurography at the peroneal nerve) was elevated by 51 +/- 14% (P baroreflex sensitivity for the control of MSNA at rest was the same as during exercise (P = 0.74) across the range of neck chamber pressures. Thus CBR control of sympathetic nerve activity appears to be preserved during moderate-intensity dynamic exercise.

  16. Liver Afferents Contribute to Water Drinking-Induced Sympathetic Activation in Human Subjects: A Clinical Trial

    Science.gov (United States)

    May, Marcus; Gueler, Faikah; Barg-Hock, Hannelore; Heiringhoff, Karl-Heinz; Engeli, Stefan; Heusser, Karsten; Diedrich, André; Brandt, André; Strassburg, Christian P.; Tank, Jens; Sweep, Fred C. G. J.; Jordan, Jens

    2011-01-01

    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 (pwater 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 PMID:22016786

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

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    Marcus May

    Full Text Available 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.ClinicalTrials.gov NCT01237431.

  18. Baroreflex activation in conscious rats modulates the joint inflammatory response via sympathetic function.

    Science.gov (United States)

    Bassi, Gabriel S; Brognara, Fernanda; Castania, Jaci A; Talbot, Jhimmy; Cunha, Thiago M; Cunha, Fernando Q; Ulloa, Luis; Kanashiro, Alexandre; Dias, Daniel P Martins; Salgado, Helio C

    2015-10-01

    The baroreflex is a critical physiological mechanism controlling cardiovascular function by modulating both the sympathetic and parasympathetic activities. Here, we report that electrical activation of the baroreflex attenuates joint inflammation in experimental arthritis induced by the administration of zymosan into the femorotibial cavity. Baroreflex activation combined with lumbar sympathectomy, adrenalectomy, celiac subdiaphragmatic vagotomy or splenectomy dissected the mechanisms involved in the inflammatory modulation, highlighting the role played by sympathetic inhibition in the attenuation of joint inflammation. From the immunological standpoint, baroreflex activation attenuates neutrophil migration and the synovial levels of inflammatory cytokines including TNF, IL-1β and IL-6, but does not affect the levels of the anti-inflammatory cytokine IL-10. The anti-inflammatory effects of the baroreflex system are not mediated by IL-10, the vagus nerve, adrenal glands or the spleen, but by the inhibition of the sympathetic drive to the knee. These results reveal a novel physiological neuronal network controlling peripheral local inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Beta blocker dose and markers of sympathetic activation in heart failure patients: interrelationships and prognostic significance.

    Science.gov (United States)

    Cohen-Solal, Alain; Jacobson, Arnold F; Piña, Ileana L

    2017-11-01

    Extent of cardiac sympathetic activation can be estimated from physiological parameters, blood biomarkers, and imaging findings. This study examined the prognostic value of three markers of sympathetic activity and their relationship to beta blocker dose in heart failure patients. A post hoc analysis of 858 heart failure subjects in the ADMIRE-HF trial was performed. Variables related to sympathetic activity were plasma norepinephrine, baseline heart rate, the heart to mediastinum (H/M) ratio of 123 I-mIBG uptake, and beta blocker dose. Univariate and multivariate analyses for occurrence of mortality (all-cause and cardiac) and arrhythmic events were performed. Beta blocker dose was significantly related to age, heart rate, b-type natriuretic peptide (negatively), body mass index, body weight and plasma norepinephrine. Univariate predictors of all-cause and cardiac mortality were baseline heart rate (χ 2  = 4.5, P = 0.029 and χ 2  = 5 .2, P = 0.022, respectively), plasma norepinephrine level (χ 2  = 8.9, P = 0.0006 and χ 2  = 8.6, P = 0.003, respectively), and H/M (χ = 22.4, P heart rate, mean heart rate >67 b.p.m. was associated with significantly higher cardiac mortality. Higher beta blocker dose was associated with lower mortality, but of the variables associated with sympathetic activity examined, cardiac 123 I-mIBG uptake was the most powerful prognostic marker in heart failure patients. Elevated heart rate was associated with greater risk for cardiac death. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

  20. Heart rate variability and muscle sympathetic nerve activity response to acute stress: the effect of breathing

    OpenAIRE

    DeBeck, Lindsay D.; Petersen, Stewart R.; Jones, Kelvin E.; Stickland, Michael K.

    2010-01-01

    Previous research has suggested a relationship between low-frequency power of heart rate variability (HRV; LF in normalized units, LFnu) and muscle sympathetic nerve activity (MSNA). However, investigations have not systematically controlled for breathing, which can modulate both HRV and MSNA. Accordingly, the aims of this experiment were to investigate the possibility of parallel responses in MSNA and HRV (LFnu) to selected acute stressors and the effect of controlled breathing. After data w...

  1. Resting sympathetic nerve activity is related to age, sex and arterial pressure but not to α2-adrenergic receptor subtype.

    Science.gov (United States)

    Maqbool, Azhar; West, Robert M; Galloway, Stacey L; Drinkhill, Mark J; Mary, David A S G; Greenwood, John P; Ball, Stephen G

    2010-10-01

    Sympathetic nerve hyperactivity has been associated with hypertension and heart failure and their cardiovascular complications. The α2-adrenergic receptors have been proposed to play a prominent role in the control of sympathetic neural output, and their malfunction to constitute a potential central mechanism for sympathetic hyperactivity of essential hypertension. Reports on the relationship between variant alleles of α2-adrenergic receptor subtypes and sympathetic drive or its effects, however, have not been consistent. Therefore, this study was planned to test the hypothesis that variant alleles of subtypes of α2-adrenergic receptors are associated with raised muscle sympathetic nerve activity (MSNA) in man. One hundred and seventy-two individuals, with a wide range of arterial pressure, were prospectively examined. Resting MSNA was quantified from multiunit bursts and from single units, and α2-adrenergic receptor subtypes were genotyped from DNA extracted from leucocytes and quantified by spectrophotometry. No significant relationships between variant alleles of any of the α2A, α2B or α2C subtypes and raised muscle sympathetic activity were found. In contrast, MSNA showed a marked significant curvilinear relationship with age and systolic pressure; sex had a small but statistically significant effect. The α2-adrenergic receptor variants had a similar frequency when hypertensive and normotensive individuals were compared. Variant alleles of three α2-adrenergic receptor subtypes were not related to resting muscle sympathetic nerve hyperactivity, indicating that their functional differences shown in vitro are not reflected in sympathetic activity in man. Age had a marked effect likely influencing arterial pressure through sympathetic activity.

  2. Local heat application to the leg reduces muscle sympathetic nerve activity in human.

    Science.gov (United States)

    Takahashi, Noriyo; Nakamura, Takeshi; Kanno, Nami; Kimura, Kenichi; Toge, Yasushi; Lee, Kyu-Ha; Tajima, Fumihiro

    2011-09-01

    The study was designed to assess the effects of local heat (LH) application on postganglionic muscle sympathetic nerve activity (MSNA) measured by microneurography in healthy men. In the first protocol, MSNA of the left peroneal nerve, blood pressure (BP), heart rate (HR), and skin temperature of the shin (TSK) were recorded in nine men. In the second protocol, leg blood flow (LBF) was measured in the same subjects by strain-gauge plethysmography. In both protocols, after 10 min of rest in the supine position, a heated hydrocollator pack was applied to the shin and anterior foot for 15 min and recovery was monitored over a period of 20 min. TSK gradually increased from 31.7 ± 0.1 to 41.9 ± 0.5°C (mean ± SEM) during LH. No subject complained of pain, and BP and HR remained constant. The MSNA burst rate (16.1 ± 2.1 beats/min) during the control period decreased significantly (P < 0.05) to 72.0 ± 2.3% during LH. Total MSNA also decreased to 59.2 ± 2.6% (P < 0.05) during LH, but both immediately returned to baseline at recovery. In contrast, LBF in the left leg significantly and immediately increased (P < 0.05) after LH application and remained significantly elevated until the end of the recovery period. These results suggest that: (1) LH application significantly attenuates MSNA without any changes in HR and BP. (2) Other factors in addition to MSNA seem to control regional blood flow in the lower extremity during LH.

  3. Suppressed sympathetic outflow to skeletal muscle, muscle thermogenesis, and activity energy expenditure with calorie restriction.

    Science.gov (United States)

    Almundarij, Tariq I; Gavini, Chaitanya K; Novak, Colleen M

    2017-02-01

    During weight loss, adaptive thermogenesis occurs where energy expenditure (EE) is suppressed beyond that predicted for the smaller body size. Here, we investigated the contributions of resting and nonresting EE to the reduced total EE seen after 3 weeks of 50% calorie restriction (CR) in rats, focusing on activity-associated EE, muscle thermogenesis, and sympathetic outflow. Prolonged food restriction resulted in a 42% reduction in daily EE, through a 40% decrease in resting EE, and a 48% decline in nonresting EE These decreases in EE were significant even when the reductions in body weight and lean mass were taken into account. Along with a decreased caloric need for low-to-moderate-intensity treadmill activity with 50% CR, baseline and activity-related muscle thermogenesis were also suppressed, though the ability to increase muscle thermogenesis above baseline levels was not compromised. When sympathetic drive was measured by assessing norepinephrine turnover (NETO), 50% CR was found to decrease NETO in three of the four muscle groups examined, whereas elevated NETO was found in white adipose tissue of food-restricted rats. Central activation of melanocortin 4 receptors in the ventromedial hypothalamus stimulated this pathway, enhancing activity EE; this was not compromised by 50% CR These data suggest that suppressed activity EE contributes to adaptive thermogenesis during energy restriction. This may stem from decreased sympathetic drive to skeletal muscle, increasing locomotor efficiency and reducing skeletal muscle thermogenesis. The capacity to increase activity EE in response to central stimuli is retained, however, presenting a potential target for preventing weight regain. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  4. The pedunculopontine tegmentum controls renal sympathetic nerve activity and cardiorespiratory activities in nembutal-anesthetized rats.

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    Anne M Fink

    Full Text Available Elevated renal sympathetic nerve activity (RSNA accompanies a variety of complex disorders, including obstructive sleep apnea, heart failure, and chronic kidney disease. Understanding pathophysiologic renal mechanisms is important for determining why hypertension is both a common sequelae and a predisposing factor of these disorders. The role of the brainstem in regulating RSNA remains incompletely understood. The pedunculopontine tegmentum (PPT is known for regulating behaviors including alertness, locomotion, and rapid eye movement sleep. Activation of PPT neurons in anesthetized rats was previously found to increase splanchnic sympathetic nerve activity and blood pressure, in addition to altering breathing. The present study is the first investigation of the PPT and its potential role in regulating RSNA. Microinjections of DL-homocysteic acid (DLH were used to probe the PPT in 100-μm increments in Nembutal-anesthetized rats to identify effective sites, defined as locations where changes in RSNA could be evoked. A total of 239 DLH microinjections were made in 18 rats, which identified 20 effective sites (each confirmed by the ability to evoke a repeatable sympathoexcitatory response. Peak increases in RSNA occurred within 10-20 seconds of PPT activation, with RSNA increasing by 104.5 ± 68.4% (mean ± standard deviation from baseline. Mean arterial pressure remained significantly elevated for 30 seconds, increasing from 101.6 ± 18.6 mmHg to 135.9 ± 36.4 mmHg. DLH microinjections also increased respiratory rate and minute ventilation. The effective sites were found throughout the rostal-caudal extent of the PPT with most located in the dorsal regions of the nucleus. The majority of PPT locations tested with DLH microinjections did not alter RSNA (179 sites, suggesting that the neurons that confer renal sympathoexcitatory functions comprise a small component of the PPT. The study also underscores the importance of further investigation to

  5. Sympathetic Neurotransmitters Modulate Osteoclastogenesis and Osteoclast Activity in the Context of Collagen-Induced Arthritis

    Science.gov (United States)

    Muschter, Dominique; Schäfer, Nicole; Stangl, Hubert; Straub, Rainer H.; Grässel, Susanne

    2015-01-01

    Excessive synovial osteoclastogenesis is a hallmark of rheumatoid arthritis (RA). Concomitantly, local synovial changes comprise neuronal components of the peripheral sympathetic nervous system. Here, we wanted to analyze if collagen-induced arthritis (CIA) alters bone marrow-derived macrophage (BMM) osteoclastogenesis and osteoclast activity, and how sympathetic neurotransmitters participate in this process. Therefore, BMMs from Dark Agouti rats at different CIA stages were differentiated into osteoclasts in vitro and osteoclast number, cathepsin K activity, matrix resorption and apoptosis were analyzed in the presence of acetylcholine (ACh), noradrenaline (NA) vasoactive intestinal peptide (VIP) and assay-dependent, adenylyl cyclase activator NKH477. We observed modulation of neurotransmitter receptor mRNA expression in CIA osteoclasts without affecting protein level. CIA stage-dependently altered marker gene expression associated with osteoclast differentiation and activity without affecting osteoclast number or activity. Neurotransmitter stimulation modulated osteoclast differentiation, apoptosis and activity. VIP, NA and adenylyl cyclase activator NKH477 inhibited cathepsin K activity and osteoclastogenesis (NKH477, 10-6M NA) whereas ACh mostly acted pro-osteoclastogenic. We conclude that CIA alone does not affect metabolism of in vitro generated osteoclasts whereas stimulation with NA, VIP plus specific activation of adenylyl cyclase induced anti-resorptive effects probably mediated via cAMP signaling. Contrary, we suggest pro-osteoclastogenic and pro-resorptive properties of ACh mediated via muscarinic receptors. PMID:26431344

  6. Arterial pressure oscillations are not associated with muscle sympathetic nerve activity in individuals exposed to central hypovolaemia

    Science.gov (United States)

    2011-09-19

    this ‘next step’ approach for investigation of non-invasive surrogates to ensure clinical utility in individual patients . This study is not without...blood pressure in health and disease. Therefore, knowing the level of sympathetic activation is important to treat patients with abnormal sympathetic...haemodynamic decompensation (i.e. pre- syncope ). Haemodynamic decompensation was identified by the attending investigator by a precipitous fall in

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

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    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.

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

    Science.gov (United States)

    Ohtani, Nobuyo; Okamoto, Yuta; Tateishi, Kanako; Uchiyama, Hidehiko; Ohta, Mitsuaki

    2015-01-01

    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.

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

    Science.gov (United States)

    Ohtani, Nobuyo; Okamoto, Yuta; Tateishi, Kanako; Uchiyama, Hidehiko; Ohta, Mitsuaki

    2015-01-01

    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. PMID:26569112

  10. Changes of Sympathetic Activity in Patient with Chronic Atrial Fibrillation and Severe Congestive Heart Failure Treated with Biventricular Pacing

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    Kohei Matsushita, MD

    2006-01-01

    Full Text Available The patient was a 64-year-old man with chronic atrial fibrillation with bradycardia. Left ventricular ejection fraction was 34%. He was treated with biventricular pacing. Heart failure improved from NYHA class III to II. Sympathetic nerve activity (SNA. was recorded during 6 minutes of biventricular (BV, right ventricular apical (RVA. and left ventricular (LV. pacing. SNA was significantly lower during biventricular pacing (49.5 ± 4.0/min. compared with RVA (58.8 ±6:9/min, p = 0.016. and LV (63.3 ± 4.3/min, p = 0.002. pacing. BV pacing improves hemodynamics and decreases SNA compared with RVA or LV pacing.

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

    Science.gov (United States)

    Yoshimura, Kenji; Maekura, Ryoji; Hiraga, Toru; Kitada, Seigo; Miki, Keisuke; Miki, Mari; Tateishi, Yoshitaka

    2012-01-01

    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. This study aimed to determine whether tiotropium use results in a sustained reduction in sympathetic activation during exercise. 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. 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. 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, which were associated with decreases in respiratory frequency and heart rate and reduced progression of arterial acidosis.

  12. Effects of Spinal Cord Stimulation on Cardiac Sympathetic Nerve Activity in Patients with Heart Failure.

    Science.gov (United States)

    Naar, Jan; Jaye, Deborah; Linde, Cecilia; Neužil, Petr; Doškář, Petr; Málek, Filip; Braunschweig, Frieder; Lund, Lars H; Mortensen, Lars; Linderoth, Bengt; Lind, Göran; Bone, Dianna; Scholte, Arthur J; Kueffer, Fred; Koehler, Jodi; Shahgaldi, Kambiz; Lang, Otto; Ståhlberg, Marcus

    2017-05-01

    Spinal cord stimulation (SCS) reduces sympathetic activity in animal models of heart failure with reduced ejection fraction (HF) but limited data exist of SCS in patients with HF. The aim of the present study was to test the primary hypothesis that SCS reduces cardiac sympathetic nerve activity in HF patients. Secondary hypotheses were that SCS improves left ventricular function and dimension, exercise capacity, and clinical variables relevant to HF. HF patients with a SCS device previously participating in the DEFEAT-HF trial were included in this crossover study with 6-week intervention periods (SCS-ON and SCS-OFF). SCS (50 Hz, 210-μs pulse duration, aiming at T2-T4 segments) was delivered for 12 hours daily. Indices of myocardial sympathetic neuronal function (heart-to-mediastinum ratio, HMR) and activity (washout rate, WR) were assessed using 123 I-metaiodobenzylguanidine (MIBG) scintigraphy. Echocardiography, exercise testing, and clinical data collection were also performed. We included 13 patients (65.3 ± 8.0 years, nine males) and MIBG scintigraphy data were available in 10. HMR was not different comparing SCS-ON (1.37 ± 0.16) and SCS-OFF (1.41 ± 0.21, P = 0.46). WR was also unchanged comparing SCS-ON (41.5 ± 5.3) and SCS-OFF (39.1 ± 5.8, P = 0.30). Similarly, average New York Heart Association class (2.4 ± 0.5 vs 2.3 ± 0.6, P = 0.34), quality of life score (24 ± 16 vs 24 ± 16, P = 0.94), and left ventricular dimension and function as well as exercise capacity were all unchanged comparing SCS-ON and SCS-OFF. In patients with HF, SCS (12 hours daily, targeting the T2-T4 segments of the spinal cord) does not appear to influence cardiac sympathetic neuronal activity or function as assessed by MIBG scintigraphy. © 2017 Wiley Periodicals, Inc.

  13. Reactive oxygen species in the paraventricular nucleus of the hypothalamus alter sympathetic activity during metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    JOSIANE CAMPOS CRUZ

    2015-12-01

    Full Text Available The paraventricular nucleus of the hypothalamus (PVN contains heterogeneous populations of neurons involved in autonomic and neuroendocrine regulation. The PVN plays an important role in the sympathoexcitatory response to increasing circulating levels of angiotensin II (Ang-II, which activates AT1 receptors in the circumventricular organs (OCVs, mainly in the subfornical organ (SFO. Circulating Ang-II induces a de novo synthesis of Ang-II in SFO neurons projecting to pre-autonomic PVN neurons. Activation of AT1 receptors induces intracellular increases in reactive oxygen species (ROS, leading to increases in sympathetic nerve activity (SNA. Chronic sympathetic nerve activation promotes a series of metabolic disorders that characterizes the metabolic syndrome (MetS: dyslipidemia, hyperinsulinemia, glucose intolerance, hyperleptinemia and elevated plasma hormone levels, such as noradrenaline, glucocorticoids, leptin, insulin and Ang-II. This review will discuss the contribution of our laboratory and others regarding the sympathoexcitation caused by peripheral Ang-II-induced reactive oxygen species along the subfornical organ and paraventricular nucleus of the hypothalamus. We hypothesize that this mechanism could be involved in metabolic disorders underlying MetS.

  14. Cardiac sympathetic activity in 22q11.2 deletion syndrome.

    Science.gov (United States)

    Verschure, Derk O; Boot, Erik; van Amelsvoort, Thérèse A; Booij, Jan; van Eck-Smit, Berthe L F; Somsen, G Aernout; Verberne, Hein J

    2016-06-01

    22q11.2 deletion syndrome (22q11.2DS) affects catechol-O-methyl-transferase (COMT), which involves the degradation of norepinephrine (NE). Clinically, adults with 22q11.2DS are at increased risk for sudden unexpected death. Although the causes are likely multifactorial, increased cardiac sympathetic activity with subsequent fatal arrhythmia, due to increased levels of NE, should be considered as a possible mechanism predisposing to this premature death. The purpose of this study was to determine whether cardiac sympathetic activity is increased in 22q11.2DS, both at baseline and following an acute NE depletion with alpha-methyl-para-tyrosine (AMPT). Five adults with 22q11.2DS and five age- and sex-matched healthy controls underwent 2 sessions with either AMPT or placebo administration before (123)I-mIBG scintigraphy. Heart-to-mediastinum ratios (H/M) were determined from the images 15min (early) and 4h (late) after administration of (123)I-mIBG and the washout (WO) was calculated as an indicator of adrenergic drive. At baseline there were no significant differences in both early and late H/M between 22q11.2DS and controls. However, there was a significant difference in WO between 22q11.2DS and controls (-4.92±2.8 and -10.44±7.2, respectively; p=0.027), but a "negative WO" does not support an increased sympathetic drive. In addition there was a trend towards a higher late H/M after AMPT administration compared to baseline which was more pronounced in 22q11.2DS. This study for the first time suggests normal cardiac sympathetic activity in adults with 22q11.2DS assessed by (123)I-mIBG scintigraphy. Although there is a small difference in adrenergic drive compared to healthy subjects, this most likely does not explain the increased unexpected death rate in the 22q11.2 DS population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. 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

    2014-01-01

    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 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 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

  16. Bradykinin Contributes to Sympathetic and Pressor Responses Evoked by Activation of Skeletal Muscle Afferents P2X in Heart Failure

    Directory of Open Access Journals (Sweden)

    Jihong Xing

    2016-11-01

    Full Text Available Background/Aims: Published data suggest that purinergic P2X receptors of muscle afferent nerves contribute to the enhanced sympathetic nervous activity (SNA and blood pressure (BP responses during static exercise in heart failure (HF. In this study, we examined engagement of bradykinin (BK in regulating responses of SNA and BP evoked by P2X stimulation in rats with HF. We further examined cellular mechanisms responsible for BK. We hypothesized that BK potentiates P2X currents of muscle dorsal root ganglion (DRG neurons, and this effect is greater in HF due to upregulation of BK kinin B2 and P2X3 receptor. As a result, BK amplifies muscle afferents P2X-mediated SNA and BP responses. Methods: Renal SNA and BP responses were recorded in control rats and rats with HF. Western Blot analysis and patch-clamp methods were employed to examine the receptor expression and function of DRG neurons involved in the effects of BK. Results: BK injected into the arterial blood supply of the hindlimb muscles heightened the reflex SNA and BP responses induced by P2X activation with α,β-methylene ATP to a greater degree in HF rats. In addition, HF upregulated the protein expression of kinin B2 and P2X3 in DRG and the prior application of BK increased the magnitude of α,β-methylene ATP-induced currents in muscle DRG neurons from HF rats. Conclusion: BK plays a facilitating role in modulating muscle afferent P2X-engaged reflex sympathetic and pressor responses. In HF, P2X responsivness is augmented due to increases in expression of kinin B2 and P2X3 receptors and P2X current activity.

  17. Muscle sympathetic nerve responses to passive and active one-legged cycling: insights into the contributions of central command.

    Science.gov (United States)

    Doherty, Connor J; Incognito, Anthony V; Notay, Karambir; Burns, Matthew J; Slysz, Joshua T; Seed, Jeremy D; Nardone, Massimo; Burr, Jamie F; Millar, Philip J

    2018-01-01

    The contribution of central command to the peripheral vasoconstrictor response during exercise has been investigated using primarily handgrip exercise. The purpose of the present study was to compare muscle sympathetic nerve activity (MSNA) responses during passive (involuntary) and active (voluntary) zero-load cycling to gain insights into the effects of central command on sympathetic outflow during dynamic exercise. Hemodynamic measurements and contralateral leg MSNA (microneurography) data were collected in 18 young healthy participants at rest and during 2 min of passive and active zero-load one-legged cycling. Arterial baroreflex control of MSNA burst occurrence and burst area were calculated separately in the time domain. Blood pressure and stroke volume increased during exercise ( P cycling ( P > 0.05). In contrast, heart rate, cardiac output, and total vascular conductance were greater during the first and second minute of active cycling ( P cycling ( P 0.05). Reductions in total MSNA were attenuated during the first ( P cycling, in concert with increased MSNA burst amplitude ( P = 0.02 and P = 0.005, respectively). The sensitivity of arterial baroreflex control of MSNA burst occurrence was lower during active than passive cycling ( P = 0.01), while control of MSNA burst strength was unchanged ( P > 0.05). These results suggest that central feedforward mechanisms are involved primarily in modulating the strength, but not the occurrence, of a sympathetic burst during low-intensity dynamic leg exercise. NEW & NOTEWORTHY Muscle sympathetic nerve activity burst frequency decreased equally during passive and active cycling, but reductions in total muscle sympathetic nerve activity were attenuated during active cycling. These results suggest that central command primarily regulates the strength, not the occurrence, of a muscle sympathetic burst during low-intensity dynamic leg exercise.

  18. 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)

  19. Insulin enhances the gain of arterial baroreflex control of muscle sympathetic nerve activity in humans.

    Science.gov (United States)

    Young, Colin N; Deo, Shekhar H; Chaudhary, Kunal; Thyfault, John P; Fadel, Paul J

    2010-09-15

    Recent animal studies indicate that insulin increases arterial baroreflex control of lumbar sympathetic nerve activity; however, the extent to which these findings can be extrapolated to humans is unknown. To begin to address this, muscle sympathetic nerve activity (MSNA) and arterial blood pressure were measured in 19 healthy subjects (27 ± 1 years) before, and for 120 min following, two common methodologies used to evoke sustained increases in plasma insulin: a mixed meal and a hyperinsulinaemic euglycaemic clamp. Weighted linear regression analysis between MSNA and diastolic blood pressure was used to determine the gain (i.e. sensitivity) of arterial baroreflex control of MSNA. Plasma insulin was significantly elevated within 30 min following meal intake (34 ± 6 uIU ml(1); P gain for burst incidence and total MSNA was increased and remained elevated for the duration of the protocol (e.g. burst incidence gain: 3.29 ± 0.54 baseline vs. 5.64 ± 0.67 bursts (100 heart beats)(1) mmHg(1) at 120 min; P gain was similarly enhanced (e.g. burst incidence gain: 2.44 ± 0.29 baseline vs. 4.74 ± 0.71 bursts (100 heart beats)(1) mmHg(1) at 120 min; P gain remained unchanged. These findings demonstrate, for the first time in healthy humans, that increases in plasma insulin enhance the gain of arterial baroreflex control of MSNA.

  20. Arterial baroreflex control of sympathetic nerve activity and heart rate in patients with type 2 diabetes.

    Science.gov (United States)

    Holwerda, Seth W; Vianna, Lauro C; Restaino, Robert M; Chaudhary, Kunal; Young, Colin N; Fadel, Paul J

    2016-11-01

    Despite greater blood pressure reactivity to acute cardiovascular stressors and a higher prevalence of hypertension in type 2 diabetes (T2D) patients, limited information is available regarding arterial baroreflex (ABR) control in T2D. We hypothesized that ABR control of muscle sympathetic nerve activity (MSNA) and heart rate (HR) are attenuated in T2D patients. Seventeen T2D patients (50 ± 2 yr; 31 ± 1 kg/m 2 ), 9 weight-matched controls (WM-CON, 46 ± 2 yr; 32 ± 2 kg/m 2 ) and 10 lean controls (Lean-CON, 49 ± 3 yr; 23 ± 1 kg/m 2 ), underwent bolus infusions of sodium nitroprusside (100 μg) followed 60 s later by phenylephrine (150 μg) and weighted linear regression performed. No group differences in overall sympathetic baroreflex gain were observed (T2D: -2.5 ± 0.3 vs. WM-CON: -2.6 ± 0.2 vs. Lean-CON: -2.7 ± 0.4 arbitrary units·beat·mmHg -1 , P > 0.05) or in sympathetic baroreflex gain when derived separately during blood pressure (BP) falls (nitroprusside) and BP rises (phenylephrine). In contrast, overall cardiac baroreflex gain was reduced in T2D patients compared with Lean-CON (T2D: 8.2 ± 1.5 vs. Lean-CON: 15.6 ± 2.9 ms·mmHg -1 , P baroreflex gain was reduced in T2D patients and weight-matched controls compared with lean controls (P 0.05). Sympathetic and cardiac ABR gains were comparable between normotensive and hypertensive T2D patients (P > 0.05). These findings suggest preserved ABR control of MSNA in T2D patients compared with both obese and lean age-matched counterparts, with a selective impairment in ABR HR control in T2D that may be related to obesity. Copyright © 2016 the American Physiological Society.

  1. Exercise training prevents the deterioration in the arterial baroreflex control of sympathetic nerve activity in chronic heart failure patients.

    Science.gov (United States)

    Groehs, Raphaela V; Toschi-Dias, Edgar; Antunes-Correa, Ligia M; Trevizan, Patrícia F; Rondon, Maria Urbana P B; Oliveira, Patrícia; Alves, Maria J N N; Almeida, Dirceu R; Middlekauff, Holly R; Negrão, Carlos E

    2015-05-01

    Arterial baroreflex control of muscle sympathetic nerve activity (ABRMSNA) is impaired in chronic systolic heart failure (CHF). The purpose of the study was to test the hypothesis that exercise training would improve the gain and reduce the time delay of ABRMSNA in CHF patients. Twenty-six CHF patients, New York Heart Association Functional Class II-III, EF ≤ 40%, peak V̇o2 ≤ 20 ml·kg(-1)·min(-1) were divided into two groups: untrained (UT, n = 13, 57 ± 3 years) and exercise trained (ET, n = 13, 49 ± 3 years). Muscle sympathetic nerve activity (MSNA) was directly recorded by microneurography technique. Arterial pressure was measured on a beat-to-beat basis. Time series of MSNA and systolic arterial pressure were analyzed by autoregressive spectral analysis. The gain and time delay of ABRMSNA was obtained by bivariate autoregressive analysis. Exercise training was performed on a cycle ergometer at moderate intensity, three 60-min sessions per week for 16 wk. Baseline MSNA, gain and time delay of ABRMSNA, and low frequency of MSNA (LFMSNA) to high-frequency ratio (HFMSNA) (LFMSNA/HFMSNA) were similar between groups. ET significantly decreased MSNA. MSNA was unchanged in the UT patients. The gain and time delay of ABRMSNA were unchanged in the ET patients. In contrast, the gain of ABRMSNA was significantly reduced [3.5 ± 0.7 vs. 1.8 ± 0.2, arbitrary units (au)/mmHg, P = 0.04] and the time delay of ABRMSNA was significantly increased (4.6 ± 0.8 vs. 7.9 ± 1.0 s, P = 0.05) in the UT patients. LFMSNA-to-HFMSNA ratio tended to be lower in the ET patients (P training prevents the deterioration of ABRMSNA in CHF patients. Copyright © 2015 the American Physiological Society.

  2. 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...... and muscle SNS activity [muscle sympathetic nervous system activity (MSNA), microneurography] in 58 males [27 Pimas/31 Caucasians]. Seven Pimas and 12 Caucasians were randomized to a double-blind, placebo-controlled, cross-over study to examine the effect of overnight partial chemical adrenalectomy...... 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....

  3. 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

    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.......The hypothalamo-pituitary-adrenal axis and sympathetic nervous system (SNS) interact to maintain cardiovascular and metabolic homeostasis, especially during stress. Pima Indians have a low SNS activity, which may contribute to both their increased risk of obesity and reduced risk of hypertension....... 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...

  4. Marital conflict and children's externalizing behavior: interactions between parasympathetic and sympathetic nervous system activity

    National Research Council Canada - National Science Library

    El-Sheikh, Mona; Beauchaine, Theodore P; Moore, Ginger A

    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...

  5. Differential effects of adrenergic antagonists (Carvedilol vs Metoprolol on parasympathetic and sympathetic activity: a comparison of clinical results

    Directory of Open Access Journals (Sweden)

    Heather L. Bloom

    2014-08-01

    Full Text Available Background Cardiovascular autonomic neuropathy (CAN is recognized as a significant health risk, correlating with risk of heart disease, silent myocardial ischemia or sudden cardiac death. Beta-blockers are often prescribed to minimize risk. Objectives In this second of two articles, the effects on parasympathetic and sympathetic activity of the alpha/beta-adrenergic blocker, Carvedilol, are compared with those of the selective beta-adrenergic blocker, Metoprolol. Methods Retrospective, serial autonomic nervous system test data from 147 type 2 diabetes mellitus patients from eight ambulatory clinics were analyzed. Patients were grouped according to whether a beta-blocker was (1 introduced, (2 discontinued or (3 continued without adjustment. Group 3 served as the control. Results Introducing Carvedilol or Metoprolol decreased heart rate and blood pressure, and discontinuing them had the opposite effect. Parasympathetic activity increased with introducing Carvedilol. Sympathetic activity increased more after discontinuing Carvedilol, suggesting better sympathetic suppression. With ongoing treatment, resting parasympathetic activity decreased with Metoprolol but increased with Carvedilol. Conclusion Carvedilol has a more profound effect on sympathovagal balance than Metoprolol. While both suppress sympathetic activity, only Carvedilol increases parasympathetic activity. Increased parasympathetic activity may underlie the lower mortality risk with Carvedilol.

  6. 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

    2015-01-01

    Key points Leptin increases sympathetic nerve activity (SNA) in males, which contributes to obesity-induced hypertension; however, whether leptin is equally effective in females is unknown. We report that leptin does increase SNA and heart rate in female rats; however, for lumbar and renal SNA, this action is only evident in pro-oestrus and in oestrogen-treated ovariectomized rats, but not in ovariectomized or dioestrus rats. Leptin increases SNA and heart rate similarly in male and pro-oestrus female rats; however, leptin increases arterial pressure only in males. Blockade of MC3/4 receptors in the paraventricular nucleus (PVN) with SHU9119 decreases SNA in leptin-treated pro-oestrus rats, suggesting that leptin increases SNA in part by increasing α-melanocyte-stimulating hormone drive of PVN presympathetic neurons. Our data establish sex differences in leptin's effects to increase SNA and arterial pressure, which emphasizes the need for enhanced recognition and investigation of sex differences in obesity-induced sympathoexcitation and hypertension. Abstract 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

  7. Effects of salt loading on sympathetic activity and blood pressure in anesthetized two-kidney, one clip hypertensive rats

    Directory of Open Access Journals (Sweden)

    Besim Özaykan

    2011-11-01

    Full Text Available In this study, we investigated the effects of salt loading on sympathetic pressor activity, cardiac autonomic activity, mean arterial pressure (MAP, heart rate (HR and on the relations between them in anesthetized two-kidney, one clip (2K1C hypertensive rats. We submitted rats to either renal artery clipping or sham operation. Distilled water or 0.5 % NaCl was given orally to the clipped and sham-operated control rats for 4 weeks. Then, MAP and HR differences between pre- and post- autonomic blockade were evaluated as indexes of sympathetic pressor and cardiac autonomic activity, respectively. The autonomic blockade decreased MAP to the similar levels in all groups (between 81.7±7.6 -87.3±7.1 mmHg. Sympathetic pressor activity was greater in the clipped rats than in its sham-operated controls only under salt loading (55.3±6.2 vs. 37.0±4.1 mmHg, p<0.05. Cardiac autonomic activity was, predominantly, sympathetic and more in the clipped group than in the sham-operated rats under distilled water (48.3±8.6 vs. 19.7±7.0 beats/min, p<0.05 but not under salt loading. Salt loading inverted the relationship between HR and cardiac autonomic activity in 2K1C hypertensive rats (r=-0.76, p=0.046 vs. r=0.89, p=0.019. These results suggest that salt loading may have augmented the effect of renovascular constriction on MAP by affecting the sympathetic pressor activity and the relation between cardiac autonomic activity and HR in 2K1C hypertensive rats.

  8. Meal-Induced Increases in Parasympathetic and Sympathetic Activity Elicit Simultaneous Rises in Plasma Insulin and Free Fatty Acids

    NARCIS (Netherlands)

    Steffens, A.B.; Gugten, J. van der; Godeke, J.; Luiten, P.G.M.; Strubbe, J.H.

    1986-01-01

    The aim of this study was to investigate sympathetic and parasympathetic activity during food intake in rats by measuring plasma norepinephrine (NE), epinephrine (E), insulin, free fatty acids (FFA), glycerol and blood glucose. Therefore male Wistar rats were implanted with silastic jugular vein

  9. Resetting of the Baroreflex Control of Sympathetic Vasomotor Activity during Natural Behaviors: Description and Conceptual Model of Central Mechanisms

    Directory of Open Access Journals (Sweden)

    Roger A. L. Dampney

    2017-08-01

    Full Text Available The baroreceptor reflex controls arterial pressure primarily via reflex changes in vascular resistance, rather than cardiac output. The vascular resistance in turn is dependent upon the activity of sympathetic vasomotor nerves innervating arterioles in different vascular beds. In this review, the major theme is that the baroreflex control of sympathetic vasomotor activity is not constant, but varies according to the behavioral state of the animal. In contrast to the view that was generally accepted up until the 1980s, I argue that the baroreflex control of sympathetic vasomotor activity is not inhibited or overridden during behaviors such as mental stress or exercise, but instead is reset under those conditions so that it continues to be highly effective in regulating sympathetic activity and arterial blood pressure at levels that are appropriate for the particular ongoing behavior. A major challenge is to identify the central mechanisms and neural pathways that subserve such resetting in different states. A model is proposed that is capable of simulating the different ways in which baroreflex resetting is occurred. Future studies are required to determine whether this proposed model is an accurate representation of the central mechanisms responsible for baroreflex resetting.

  10. Resetting of the Baroreflex Control of Sympathetic Vasomotor Activity during Natural Behaviors: Description and Conceptual Model of Central Mechanisms

    Science.gov (United States)

    Dampney, Roger A. L.

    2017-01-01

    The baroreceptor reflex controls arterial pressure primarily via reflex changes in vascular resistance, rather than cardiac output. The vascular resistance in turn is dependent upon the activity of sympathetic vasomotor nerves innervating arterioles in different vascular beds. In this review, the major theme is that the baroreflex control of sympathetic vasomotor activity is not constant, but varies according to the behavioral state of the animal. In contrast to the view that was generally accepted up until the 1980s, I argue that the baroreflex control of sympathetic vasomotor activity is not inhibited or overridden during behaviors such as mental stress or exercise, but instead is reset under those conditions so that it continues to be highly effective in regulating sympathetic activity and arterial blood pressure at levels that are appropriate for the particular ongoing behavior. A major challenge is to identify the central mechanisms and neural pathways that subserve such resetting in different states. A model is proposed that is capable of simulating the different ways in which baroreflex resetting is occurred. Future studies are required to determine whether this proposed model is an accurate representation of the central mechanisms responsible for baroreflex resetting. PMID:28860965

  11. Activation of hypothalamic RIP-Cre neurons promotes beiging of WAT via sympathetic nervous system.

    Science.gov (United States)

    Wang, Baile; Li, Ang; Li, Xiaomu; Ho, Philip Wl; Wu, Donghai; Wang, Xiaoqi; Liu, Zhuohao; Wu, Kelvin Kl; Yau, Sonata Sy; Xu, Aimin; Cheng, Kenneth Ky

    2018-04-01

    Activation of brown adipose tissue (BAT) and beige fat by cold increases energy expenditure. Although their activation is known to be differentially regulated in part by hypothalamus, the underlying neural pathways and populations remain poorly characterized. Here, we show that activation of rat-insulin-promoter-Cre (RIP-Cre) neurons in ventromedial hypothalamus (VMH) preferentially promotes recruitment of beige fat via a selective control of sympathetic nervous system (SNS) outflow to subcutaneous white adipose tissue (sWAT), but has no effect on BAT Genetic ablation of APPL2 in RIP-Cre neurons diminishes beiging in sWAT without affecting BAT, leading to cold intolerance and obesity in mice. Such defects are reversed by activation of RIP-Cre neurons, inactivation of VMH AMPK, or treatment with a β3-adrenergic receptor agonist. Hypothalamic APPL2 enhances neuronal activation in VMH RIP-Cre neurons and raphe pallidus, thereby eliciting SNS outflow to sWAT and subsequent beiging. These data suggest that beige fat can be selectively activated by VMH RIP-Cre neurons, in which the APPL2-AMPK signaling axis is crucial for this defending mechanism to cold and obesity. © 2018 The Authors.

  12. 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

    The function of sympathetic vasoconstrictor fibres was studied in 18 patients with occlusive arterial disease of the legs and somatic neuropathy, as evidenced as an increased vibration perception threshold. Nine patients suffered from long-term diabetes mellitus. Sympathetic vasoconstrictor...... of vibration sense, abnormal vasoconstrictor function was found. In three of these patients, the abnormal response most likely could be ascribed to impaired function of the vascular smooth muscle cells. Neither in diabetics nor in non-diabetics could an abnormal vibration sense be taken as evidence for loss...... of sympathetic vasoconstrictor function. It is suggested that this is studied by a simple postural test as used in the present study....

  13. The assessment of sympathetic activity using iPPG based inter-limb coherence measurements

    Science.gov (United States)

    Tsoy, Maria O.; Rogatina, Kristina V.; Stiukhina, Elena S.; Postnov, Dmitry E.

    2017-04-01

    Photoplethysmography is an optical technique that can be used to detect blood volume changes and to measure important physiological parameters. This is low cost and non-invasive technique. However, one has to apply sensor directly to the skin. In this regard, the development on remote mothods receives the growing attention, such as imaging photoplethysmography (iPPG). Note, most of public-available iPPG systems are based on smartphone-embedded cameras, and thus have a sample frequency about 30-60 frames per second, which is enough for heart rate measurements, but may be too low for some more advanced usages of this technique. In our work, we describe the attempt to use smartphone-based iPPG technique aimed to measure the tiny mismatch in RR interval data series recorded from left and right arms. We use the transmission mode iPPG, in which the light transmitted through the medium of finger is detected by a web-camera opposite the LED source. The computational scheme by processing and analysis of the received signal was implemented using MATLAB language (MathWork Inc. in the United States). We believe that further development of our approach may lead to fast and low cost method to access the state of the sympathetic nervous system.

  14. Lowering of blood pressure by chronic suppression of central sympathetic outflow: insight from prolonged baroreflex activation

    Science.gov (United States)

    Iliescu, Radu

    2012-01-01

    Device-based therapy for resistant hypertension by electrical activation of the carotid baroreflex is currently undergoing active clinical investigation, and initial findings from clinical trials have been published. The purpose of this mini-review is to summarize the experimental studies that have provided a conceptual understanding of the mechanisms that account for the long-term lowering of arterial pressure with baroreflex activation. The well established mechanisms mediating the role of the baroreflex in short-term regulation of arterial pressure by rapid changes in peripheral resistance and cardiac function are often extended to long-term pressure control, and the more sluggish actions of the baroreflex on renal excretory function are often not taken into consideration. However, because clinical, experimental, and theoretical evidence indicates that the kidneys play a dominant role in long-term control of arterial pressure, this review focuses on the mechanisms that link baroreflex-mediated reductions in central sympathetic outflow with increases in renal excretory function that lead to sustained reductions in arterial pressure. PMID:22797307

  15. Hypoxia mediated pulmonary edema: potential influence of oxidative stress, sympathetic activation and cerebral blood flow.

    Science.gov (United States)

    Khademi, Shadi; Frye, Melinda A; Jeckel, Kimberly M; Schroeder, Thies; Monnet, Eric; Irwin, Dave C; Cole, Patricia A; Bell, Christopher; Miller, Benjamin F; Hamilton, Karyn L

    2015-10-09

    Neurogenic pulmonary edema (NPE) is a non-cardiogenic form of pulmonary edema that can occur consequent to central neurologic insults including stroke, traumatic brain injury, and seizure. NPE is a public health concern due to high morbidity and mortality, yet the mechanism(s) are unknown. We hypothesized that NPE, evoked by cerebral hypoxia in the presence of systemic normoxia, would be accompanied by sympathetic activation, oxidative stress, and compensatory antioxidant mechanisms. Thirteen Walker hounds were assigned to cerebral hypoxia (SaO2 ~ 55 %) with systemic normoxia (SaO2 ~ 90 %) (CH; n = 6), cerebral and systemic (global) hypoxia (SaO2 ~ 60 %) (GH; n = 4), or cerebral and systemic normoxia (SaO2 ~ 90 %) (CON; n = 3). Femoral venous (CH and CON) perfusate was delivered via cardiopulmonary bypass to the brain and GH was induced by FiO2 = 10 % to maintain the SaO2 at ~60 %. Lung wet to lung dry weight ratios (LWW/LDW) were assessed as an index of pulmonary edema in addition to hemodynamic measurements. Plasma catecholamines were measured as markers of sympathetic nervous system (SNS) activity. Total glutathione, protein carbonyls, and malondialdehyde were assessed as indicators of oxidative stress. Brain and lung compensatory antioxidants were measured with immunoblotting. Compared to CON, LWW/LDW and pulmonary artery pressure were greater in CH and GH. Expression of hemeoxygenase-1 in brain was higher in CH compared to GH and CON, despite no group differences in oxidative damage in any tissue. Catecholamines tended to be higher in CH and GH. Cerebral hypoxia, with systemic normoxia, is not systematically associated with an increase in oxidative stress and compensatory antioxidant enzymes in lung, suggesting oxidative stress did not contribute to NPE in lung. However, increased SNS activity may play a role in the induction of NPE during hypoxia.

  16. 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.

  17. Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans

    Science.gov (United States)

    Cui, Jian; McQuillan, Patrick M.; Blaha, Cheryl; Kunselman, Allen R.

    2012-01-01

    We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects. PMID:22707559

  18. Slow and deep respiration suppresses steady-state sympathetic nerve activity in patients with chronic heart failure: from modeling to clinical application.

    Science.gov (United States)

    Harada, Daisuke; Asanoi, Hidetsugu; Takagawa, Junya; Ishise, Hisanari; Ueno, Hiroshi; Oda, Yoshitaka; Goso, Yukiko; Joho, Shuji; Inoue, Hiroshi

    2014-10-15

    Influences of slow and deep respiration on steady-state sympathetic nerve activity remain controversial in humans and could vary depending on disease conditions and basal sympathetic nerve activity. To elucidate the respiratory modulation of steady-state sympathetic nerve activity, we modeled the dynamic nature of the relationship between lung inflation and muscle sympathetic nerve activity (MSNA) in 11 heart failure patients with exaggerated sympathetic outflow at rest. An autoregressive exogenous input model was utilized to simulate entire responses of MSNA to variable respiratory patterns. In another 18 patients, we determined the influence of increasing tidal volume and slowing respiratory frequency on MSNA; 10 patients underwent a 15-min device-guided slow respiration and the remaining 8 had no respiratory modification. The model predicted that a 1-liter, step increase of lung volume decreased MSNA dynamically; its nadir (-33 ± 22%) occurred at 2.4 s; and steady-state decrease (-15 ± 5%), at 6 s. Actually, in patients with the device-guided slow and deep respiration, respiratory frequency effectively fell from 16.4 ± 3.9 to 6.7 ± 2.8/min (P steady-state MSNA was decreased by 31% (P steady-state MSNA. Thus slow and deep respiration suppresses steady-state sympathetic nerve activity in patients with high levels of resting sympathetic tone as in heart failure. Copyright © 2014 the American Physiological Society.

  19. 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.

  20. Arterial baroreflex control of sympathetic nerve activity during acute hypotension: effect of fitness

    Science.gov (United States)

    Fadel, P. J.; Stromstad, M.; Hansen, J.; Sander, M.; Horn, K.; Ogoh, S.; Smith, M. L.; Secher, N. H.; Raven, P. B.

    2001-01-01

    We examined arterial baroreflex control of muscle sympathetic nerve activity (MSNA) during abrupt decreases in mean arterial pressure (MAP) and evaluated whether endurance training alters baroreflex function. Acute hypotension was induced nonpharmacologically in 14 healthy subjects, of which 7 were of high fitness (HF) and 7 were of average fitness (AF), by releasing a unilateral arterial thigh cuff after 9 min of resting ischemia under two conditions: control, which used aortic and carotid baroreflex (ABR and CBR, respectively) deactivation; and suction, which used ABR deactivation alone. The application of neck suction to counteract changes in carotid sinus transmural pressure during cuff release significantly attenuated the MSNA response (which increased 134 +/- 32 U/14 s) compared with control (which increased 195 +/- 43 U/14 s) and caused a greater decrease in MAP (19 +/- 2 vs. 15 +/- 2 mmHg; P control of MSNA. These data indicate that the CBR contributes importantly to the MSNA response during acute systemic hypotension. Additionally, we suggest that an impaired control of vascular reactivity hinders blood pressure regulation in HF subjects.

  1. Arterial baroreflex control of sympathetic nerve activity during acute hypotension: effect of fitness

    Science.gov (United States)

    Fadel, P. J.; Stromstad, M.; Hansen, J.; Sander, M.; Horn, K.; Ogoh, S.; Smith, M. L.; Secher, N. H.; Raven, P. B.

    2001-01-01

    We examined arterial baroreflex control of muscle sympathetic nerve activity (MSNA) during abrupt decreases in mean arterial pressure (MAP) and evaluated whether endurance training alters baroreflex function. Acute hypotension was induced nonpharmacologically in 14 healthy subjects, of which 7 were of high fitness (HF) and 7 were of average fitness (AF), by releasing a unilateral arterial thigh cuff after 9 min of resting ischemia under two conditions: control, which used aortic and carotid baroreflex (ABR and CBR, respectively) deactivation; and suction, which used ABR deactivation alone. The application of neck suction to counteract changes in carotid sinus transmural pressure during cuff release significantly attenuated the MSNA response (which increased 134 +/- 32 U/14 s) compared with control (which increased 195 +/- 43 U/14 s) and caused a greater decrease in MAP (19 +/- 2 vs. 15 +/- 2 mmHg; P baroreflex control of MSNA. These data indicate that the CBR contributes importantly to the MSNA response during acute systemic hypotension. Additionally, we suggest that an impaired control of vascular reactivity hinders blood pressure regulation in HF subjects.

  2. Increased sympathetic activity during sleep and nocturnal hypertension in Type 2 diabetic patients with diabetic nephropathy

    DEFF Research Database (Denmark)

    Nielsen, F S; Hansen, H P; Jacobsen, P

    1999-01-01

    AIMS: To elucidate the putative factors involved in the blunted nocturnal blood pressure reduction in hypertensive Type 2 diabetic patients with diabetic nephropathy. METHODS: Extracellular fluid volume and fluid shift from interstitial to plasma volume (haematocrit), sympathetic nervous activity...... with the patients lying awake in bed from 21:30 to 23:00 h (baseline) and during sleep from 23:00 to 07:00 h. Using the median nocturnal blood pressure reduction (8.4%) as a guide, the patients were divided into groups; group 1 with the highest and group 2 with the lowest nocturnal blood pressure reduction. RESULTS......: Haematocrit decreased from baseline to the sleep period in group 1 by a mean (95% confidence interval (CI)) of 1.7 (0.3-3.1)%, but it increased by 0.5 (-1.0-1.9)% in group 2, mean difference (95% CI), -2.1 (-4.0 to -0.2)% (P = 0.029). Noradrenaline decreased from baseline to the sleep period, mean (95% CI...

  3. 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

    /UTP-selective receptors. To this aim, we first measured leg blood flow (LBF), mean arterial pressure (MAP), cardiac output , leg arterial-venous (a-v) O(2) difference, plasma ATP and soluble nucleotidase activities during intrafemoral artery infusion of adenosine, AMP, ADP, ATP or UTP in nine healthy males. Comparison.......8) > ADP (2.7) > AMP (1.7). The infusions did not cause any shifts in plasma ATP level or soluble serum nucleotidase activities. Combined infusion of the vasodilatory compounds and the sympathetic vasoconstrictor drug tyramine increased plasma noradrenaline in all hyperaemic conditions, but only caused leg......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...

  4. 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.

    2013-01-01

    While leptin is known to increase sympathetic nerve activity (SNA), we tested the hypothesis that leptin also enhances baroreflex control of SNA and 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 hr after lateral cerebroventricular (LV) leptin or aCSF administration. Baroreflex function was assessed using a four parameter sigmoidal fit of HR and SNA responses to slow ramp (3-5 min) changes in MAP, induced by iv infusion of nitroprusside and phenylephrine. Leptin (3 μg) increased (Pbaroreflex 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. LV aCSF had no effects. Finally, to test if leptin acts in the brainstem, 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

  5. Mindfulness meditation lowers muscle sympathetic nerve activity and blood pressure in African-American males with chronic kidney disease.

    Science.gov (United States)

    Park, Jeanie; Lyles, Robert H; Bauer-Wu, Susan

    2014-07-01

    Mindfulness meditation (MM) is a stress-reduction technique that may have real biological effects on hemodynamics but has never previously been tested in chronic kidney disease (CKD) patients. In addition, the mechanisms underlying the potential blood pressure (BP)-lowering effects of MM are unknown. We sought to determine whether MM acutely lowers BP in CKD patients, and whether these hemodynamic changes are mediated by a reduction in sympathetic nerve activity. In 15 hypertensive African-American (AA) males with CKD, we conducted a randomized, crossover study in which participants underwent 14 min of MM or 14 min of BP education (control intervention) during two separate random-order study visits. Muscle sympathetic nerve activity (MSNA), beat-to-beat arterial BP, heart rate (HR), and respiratory rate (RR) were continuously measured at baseline and during each intervention. A subset had a third study visit to undergo controlled breathing (CB) to determine whether a reduction in RR alone was sufficient in exacting hemodynamic changes. We observed a significantly greater reduction in systolic BP, diastolic BP, mean arterial pressure, and HR, as well as a significantly greater reduction in MSNA, during MM compared with the control intervention. Participants had a significantly lower RR during MM; however, in contrast to MM, CB alone did not reduce BP, HR, or MSNA. MM acutely lowers BP and HR in AA males with hypertensive CKD, and these hemodynamic effects may be mediated by a reduction in sympathetic nerve activity. RR is significantly lower during MM, but CB alone without concomitant meditation does not acutely alter hemodynamics or sympathetic activity in CKD.

  6. Optically activated magnetic recording tape

    Science.gov (United States)

    Marks, A. M.; Shulman, A. R.

    1970-01-01

    Optically activated data storage medium visually and electromagnetically reproduces a recorded signal. In an electric field, particles in heat-fluidized thermoplastic layer form a visible image of the recorded signal. Refluidizing the thermoplastic layer erases the signals. Very high data packing densities are achieved.

  7. Expression of adenosine triphosphate-sensitive potassium channels in rats with cirrhosis: correlationship with sympathetic activity and renal function

    Directory of Open Access Journals (Sweden)

    Julio Cesar Martins Monte

    2006-12-01

    Full Text Available Objective: The aim of this study was to perform a direct analysis ofKATP mRNA expression by RT-PCR in kidney and isolated aorta fromrats with cirrhosis (induced by carbon tetrachloride and controls.The present study also analyses the relation between induced cirrhosisand urinary excretion of sodium and sympathetic activity in cirrhoticrats. Methods: Rats were placed in metabolic cages and allowedfree access to food and water. Cirrhosis was induced by repeateddoses of carbon tetrachloride by gastric gavage. After some weeks,the kidney and aorta were dissected and utilized for RNA extraction.Blood and urine were analyzed for electrolytes. Renal function wasestimated by creatinine clearance and sodium urinary excretion.Serum catecholamines were measured by HPLC analysis. Results:First, RT-PCR analysis showed that KATP mRNA is expressed in liverwith cirrhosis and intense fibrosis, but not with moderate fibrosis.Second, RT-PCR analysis revealed that KATP mRNA was detectedonly in aorta dissected from rats with cirrhosis. Finally, an enhancedreabsorption of sodium without renal failure suggests a potentialmediator would increase the activity of the sympathetic system.Conclusion: These results suggest that KATP mRNA is expressed incirrhotic rats with sympathetic activation and renal dysfunction. Thischannel might be involved in another route where the vascular tonecan be modulated in cirrhosis.

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

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    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

  9. Midazolam more effectively suppresses sympathetic activations and reduces stress feelings during mental arithmetic task than propofol.

    Science.gov (United States)

    Tsugayasu, Rie; Handa, Toshiyuki; Kaneko, Yuzuru; Ichinohe, Tatsuya

    2010-03-01

    The aim of the present study was to examine the effect of intravenous midazolam and propofol sedation on autonomic nervous activities during psychological stress, and whether these results are associated with changes in subjective stress feelings. Seven healthy male volunteers were included in a randomized crossover manner. The heart rate (HR), HR variability, arterial oxygen saturation, and bispectral index value were continuously monitored. A mental arithmetic task for 7 minutes was given with or without intravenous sedation with midazolam or propofol. A bispectral index value of 75 to 85 and an Observer's Assessment of Alertness/Sedation score of 4 were the targeted sedation level in both groups. HR variability was assessed using the power spectral analysis (low-frequency [LF] and high-frequency [HF] components and LF/HF ratio). The faces anxiety scale was used to grade their stress feelings after each mental arithmetic task. During the mental arithmetic task with intravenous sedation, no differences were found in the bispectral index values, arterial oxygen saturation, or the results of the mental arithmetic task between the 2 groups. The HR, LF/HF ratio, and normalized unit LF increased, and the normalized unit HF decreased in both groups. However, the percentage of changes in LF/HF ratio, normalized unit LF, and normalized unit HF were smaller in the midazolam group. In addition, the reduction in faces anxiety scale was greater in the midazolam group. These results suggest that midazolam more effectively suppresses sympathetic nervous activation and reduces subjective stress feelings during a mental arithmetic task than propofol. Copyright (c) 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  10. Selective activation of heterologously expressed G protein-gated K+ channels by M2 muscarinic receptors in rat sympathetic neurones

    Science.gov (United States)

    Fernandez-Fernandez, Jose M; Wanaverbecq, Nicolas; Halley, Pam; Caulfield, Malcolm P; Brown, David A

    1999-01-01

    G protein-regulated inward rectifier K+ (GIRK) channels were over-expressed in dissociated rat superior cervical sympathetic (SCG) neurones by co-transfecting green fluorescent protein (GFP)-, GIRK1- and GIRK2-expressing plasmids using the biolistic technique. Membrane currents were subsequently recorded with whole-cell patch electrodes.Co-transfected cells had larger Ba2+-sensitive inwardly rectifying currents and 13 mV more negative resting potentials (in 3 mm[K+]o) than non-transfected cells, or cells transfected with GIRK1 or GIRK2 alone.Carbachol (CCh, 1–30 μm) increased the inwardly rectifying current in 70% of GIRK1+ GIRK2-transfected cells by 261 ± 53% (n = 6, CCh 30 μm) at −120 mV, but had no effect in non-transfected cells or in cells transfected with GIRK1 or GIRK2 alone. Pertussis toxin prevented the effect of carbachol but had no effect on basal currents.The effect of CCh was antagonized by 6 nm tripitramine but not by 100 nm pirenzepine, consistent with activation of endogenous M2 muscarinic acetylcholine receptors.In contrast, inhibition of the voltage-activated Ca2+ current by CCh was antagonized by 100 nm pirenzepine but not by 6 nm tripitramine, indicating that it was mediated by M4 muscarinic acetylcholine receptors.We conclude that endogenous M2 and M4 muscarinic receptors selectively couple to GIRK currents and Ca2+ currents respectively, with negligible cross-talk. PMID:10066893

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

    NARCIS (Netherlands)

    van den Berg, M.M.H.E.; Maas, J.; Muller, R.; Braun, A.; Kaandorp, W.; van Lien, R.; van Poppel, M.N.M.; van Mechelen, W.; van den Berg, A.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

  12. 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.

  13. Turo (qi dance) training attenuates psychological symptoms and sympathetic activation induced by mental stress in healthy women.

    Science.gov (United States)

    Lee, Hwa-Jin; Chae, Younbyoung; Park, Hi-Joon; Hahm, Dae-Hyun; An, Kyungeh; Lee, Hyejung

    2009-09-01

    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.

  14. 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. Copyright © 2016 the American Physiological Society.

  15. Standardization of I-123-meta-iodobenzylguanidine myocardial sympathetic activity imaging: phantom calibration and clinical applications

    NARCIS (Netherlands)

    Nakajima, Kenichi; Verschure, Derk O.; Okuda, Koichi; Verberne, Hein J.

    2017-01-01

    Purpose Myocardial sympathetic imaging with I-123-meta-iodobenzylguanidine (I-123-mIBG) has gained clinical momentum. Although the need for standardization of I-123-mIBG myocardial uptake has been recognized, the availability of practical clinical standardization approaches is limited. The need for

  16. Cardiac sympathetic activity in hypertrophic cardiomyopathy and Tako-tsubo cardiomyopathy

    NARCIS (Netherlands)

    Verschure, Derk O.; van Eck-Smit, Berthe L. F.; Somsen, G. Aernout; Verberne, Hein J.

    2015-01-01

    (123)I-meta-iodobenzylguanidine ((123)I-mIBG) scintigraphy has been established as an important technique to evaluate cardiac sympathetic function and it has been shown to be of clinical value, especially for the assessment of prognosis, in many cardiac diseases. The majority of (123)I-mIBG

  17. 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

  18. Direct evidences for sympathetic hyperactivity and baroreflex impairment in Tako Tsubo cardiopathy.

    Directory of Open Access Journals (Sweden)

    Angelica Vaccaro

    Full Text Available BACKGROUND: The exact pathophysiology of Tako-Tsubo cardiomyopathy (TTC remains unknown but a role for sympathetic hyperactivity has been suggested. Up to now, no direct evidence of sympathetic nerve hyperactivity has been established nor involvement of sympathetic baroreflex identified. The aim of our study was to determine, by direct sympathetic nerve activity (SNS recording if sympathetic nervous system activity is increased and spontaneous baroreflex control of sympathetic activity reduced in patients with TTC. METHODS: We included 13 patients who presented with TTC and compared their SNS activity and spontaneous baroreflex control of sympathetic activity with that of 13 control patients with acutely decompensated chronic heart failure. SNS activity was evaluated by microneurography, a technique assessing muscle sympathetic nerve activity (MSNA. Spontaneous baroreflex control of sympathetic activity was evaluated as the absolute value of the slope of the regression line representing the relationship between spontaneous diastolic blood pressure values and concomitant SNS activity. Control patients were matched for age, sex, left ventricular ejection fraction and creatinine clearance. RESULTS: The mean age of the patients with TTC was 80 years, all patients were women. There were no significant differences between the two groups of patients for blood pressure, heart rate or oxygen saturation level. TTC patients presented a significant increase in sympathetic nerve activity (MSNA median 63.3 bursts/min [interquartile range 61.3 to 66.0] vs median 55.7 bursts/min [interquartile range 51.0 to 61.7]; p = 0.0089 and a decrease in spontaneous baroreflex control of sympathetic activity compared to matched control patients (spontaneous baroreflex control of sympathetic activity median 0.7%burst/mmHg [interquartile range 0.4 to 1.9] vs median 2.4%burst/mmHg [interquartile range 1.8 to 2.9]; p = 0.005. CONCLUSIONS: We report for the first time, through

  19. Direct evidences for sympathetic hyperactivity and baroreflex impairment in Tako Tsubo cardiopathy.

    Science.gov (United States)

    Vaccaro, Angelica; Despas, Fabien; Delmas, Clement; Lairez, Olivier; Lambert, Elisabeth; Lambert, Gavin; Labrunee, Marc; Guiraud, Thibaut; Esler, Murray; Galinier, Michel; Senard, Jean Michel; Pathak, Atul

    2014-01-01

    The exact pathophysiology of Tako-Tsubo cardiomyopathy (TTC) remains unknown but a role for sympathetic hyperactivity has been suggested. Up to now, no direct evidence of sympathetic nerve hyperactivity has been established nor involvement of sympathetic baroreflex identified. The aim of our study was to determine, by direct sympathetic nerve activity (SNS) recording if sympathetic nervous system activity is increased and spontaneous baroreflex control of sympathetic activity reduced in patients with TTC. We included 13 patients who presented with TTC and compared their SNS activity and spontaneous baroreflex control of sympathetic activity with that of 13 control patients with acutely decompensated chronic heart failure. SNS activity was evaluated by microneurography, a technique assessing muscle sympathetic nerve activity (MSNA). Spontaneous baroreflex control of sympathetic activity was evaluated as the absolute value of the slope of the regression line representing the relationship between spontaneous diastolic blood pressure values and concomitant SNS activity. Control patients were matched for age, sex, left ventricular ejection fraction and creatinine clearance. The mean age of the patients with TTC was 80 years, all patients were women. There were no significant differences between the two groups of patients for blood pressure, heart rate or oxygen saturation level. TTC patients presented a significant increase in sympathetic nerve activity (MSNA median 63.3 bursts/min [interquartile range 61.3 to 66.0] vs median 55.7 bursts/min [interquartile range 51.0 to 61.7]; p = 0.0089) and a decrease in spontaneous baroreflex control of sympathetic activity compared to matched control patients (spontaneous baroreflex control of sympathetic activity median 0.7%burst/mmHg [interquartile range 0.4 to 1.9] vs median 2.4%burst/mmHg [interquartile range 1.8 to 2.9]; p = 0.005). We report for the first time, through direct measurement of sympathetic nerve activity, that

  20. 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.

  1. Autonomic nervous system responses to viewing green and built settings: : differentiating between sympathetic and parasympathetic activity

    NARCIS (Netherlands)

    van den Berg, Magdalena; Maas, Jolanda; Mulder, Rianne; Braun, Anoek; Kaandorp, Wendy; van Lien, René; van Poppel, Mireille; van Mechelen, Willem; van den Berg, Agnes

    2015-01-01

    his 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

  2. 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.

  3. Role of small conductance calcium-activated potassium channels expressed in PVN in regulating sympathetic nerve activity and arterial blood pressure in rats

    OpenAIRE

    Gui, Le; LaGrange, Lila P.; Larson, Robert A.; Gu, Mingjun; Zhu, Jianhua; Chen, Qing-Hui

    2012-01-01

    Small conductance Ca2+-activated K+ (SK) channels regulate membrane properties of rostral ventrolateral medulla (RVLM) projecting hypothalamic paraventricular nucleus (PVN) neurons and inhibition of SK channels increases in vitro excitability. Here, we determined in vivo the role of PVN SK channels in regulating sympathetic nerve activity (SNA) and mean arterial pressure (MAP). In anesthetized rats, bilateral PVN microinjection of SK channel blocker with peptide apamin (0, 0.125, 1.25, 3.75, ...

  4. Effects of L-arginine and L-lysine mixtures on splenic sympathetic nerve activity and tumor proliferation.

    Science.gov (United States)

    Shen, Jiao; Horii, Yuko; Fujisaki, Yoshiyuki; Nagai, Katsuya

    2009-05-11

    Oral supplementations of L-arginine and L-lysine show tumor inhibition abilities. The splenic sympathetic nerve is involved in central modulation of cellular immunity and suppresses splenic natural killer cell activity in rats. An intravenous administration of a mixture of 10 mM L-arginine and L-lysine decreased splenic sympathetic nerve activity (splenic-SNA). We examined the effect of L-arginine and L-lysine mixtures on splenic-SNA in urethane-anesthetized rats by administration of 1 ml mixtures of 2 mM, 10 mM, and 50 mM L-arginine and L-lysine. We also studied the effect of the above mixtures on human colon cancer cell proliferation in athymic nude mice. An increase in splenic-SNA and tumor volume (2 mM), no effect (10 mM), and a decrease in both values (50 mM) were seen. Bivariate correlation analysis revealed a positive correlation between changes in splenic-SNA and tumor volume, indicating the tumor suppressing ability of weakened splenic-SNA.

  5. 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. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Unstable sleep and higher sympathetic activity during late-sleep periods of rats: implication for late-sleep-related higher cardiovascular events.

    Science.gov (United States)

    Kuo, Terry B J; Lai, Chun-Ting; Chen, Chun-Yu; Lee, Guo-She; Yang, Cheryl C H

    2013-02-01

    We proposed that the higher incidence of sleep fragmentation, sympathovagal imbalance and baroreceptor reflex impairment during quiet sleep may play a critical role in late-sleep-related cardiovascular events. Polysomnographic recording was performed through wireless transmission using freely moving Wistar-Kyoto rats over 24 h. The low-frequency power of arterial pressure variability was quantified to provide an index of vascular sympathetic activity. Spontaneous baroreflex sensitivity was assessed by slope of arterial pressure-RR linear regression. As compared with early-light period (Zeitgeber time 0-6 h), rats during the late-light period (Zeitgeber time 6-12 h) showed lower accumulated quiet sleep time and higher paradoxical sleep time; furthermore, during quiet sleep, the rats showed a lower δ% of electroencephalogram, more incidents of interruptions, higher σ% and higher β% of electroencephalogram, raised low-frequency power of arterial pressure variability value and lower baroreflex sensitivity parameters. During the light period, low-frequency power of arterial pressure variability during quiet sleep had a negative correlation with accumulated quiet sleep time and δ% of electroencephalogram, while it also had a positive correlation with σ% and β% of electroencephalogram and interruption events. However, late-sleep-related raised sympathetic activity and sleep fragmentation diminished when an α1-adrenoceptor antagonist was given to the rats. Our results suggest that the higher incidence of sleep fragmentation and sympathovagal imbalance during quiet sleep may play a critical role in late-sleep-related cardiovascular events. Such sleep fragmentation is coincident with an impairment of baroreflex sensitivity, and is mediated via α1-adernoceptors. © 2012 European Sleep Research Society.

  7. (In)activity-related neuroplasticity in brainstem control of sympathetic outflow: unraveling underlying molecular, cellular, and anatomical mechanisms

    Science.gov (United States)

    Mischel, Nicholas A.; Subramanian, Madhan; Dombrowski, Maryetta D.; Llewellyn-Smith, Ida J.

    2015-01-01

    More people die as a result of physical inactivity than any other preventable risk factor including smoking, high cholesterol, and obesity. Cardiovascular disease, the number one cause of death in the United States, tops the list of inactivity-related diseases. Nevertheless, the vast majority of Americans continue to make lifestyle choices that are creating a rapidly growing burden of epidemic size and impact on the United States healthcare system. It is imperative that we improve our understanding of the mechanisms by which physical inactivity increases the incidence of cardiovascular disease and how exercise can prevent or rescue the inactivity phenotype. The current review summarizes research on changes in the brain that contribute to inactivity-related cardiovascular disease. Specifically, we focus on changes in the rostral ventrolateral medulla (RVLM), a critical brain region for basal and reflex control of sympathetic activity. The RVLM is implicated in elevated sympathetic outflow associated with several cardiovascular diseases including hypertension and heart failure. We hypothesize that changes in the RVLM contribute to chronic cardiovascular disease related to physical inactivity. Data obtained from our translational rodent models of chronic, voluntary exercise and inactivity suggest that functional, anatomical, and molecular neuroplasticity enhances glutamatergic neurotransmission in the RVLM of sedentary animals. Collectively, the evidence presented here suggests that changes in the RVLM resulting from sedentary conditions are deleterious and contribute to cardiovascular diseases that have an increased prevalence in sedentary individuals. The mechanisms by which these changes occur over time and their impact are important areas for future study. PMID:25957223

  8. A comparative study of changes operated by sympathetic nervous system activation on spindle afferent discharge and on tonic vibration reflex in rabbit jaw muscles.

    Science.gov (United States)

    Passatore, M; Deriu, F; Grassi, C; Roatta, S

    1996-03-07

    The effect of sympathetic activation on the spindle afferent response to vibratory stimuli eliciting the tonic vibration reflex in jaw closing muscles was studied in precollicularly decerebrate rabbits. Stimulation of the cervical sympathetic trunk, at frequencies within the physiologic range, consistently induced a decrease in spindle response to muscle vibration, which was often preceded by a transient enhancement. Spindle discharge was usually correlated with the EMG activity in the masseter muscle and the tension reflexly developed by jaw muscles. The changes in spindle response to vibration were superimposed on variations of the basal discharge which exhibited different patterns in the studied units, increases in the firing rate being more frequently observed. These effects were mimicked by close arterial injection of the selective alpha 1-adrenoceptor agonist phenylephrine. Data presented here suggest that sympathetically-induced modifications of the tonic vibration reflex are due to changes exerted on muscle spindle afferent information.

  9. 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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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

  11. 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.

    2015-01-01

    Refractory hypertension is an extreme phenotype of treatment failure defined as uncontrolled blood pressure (BP) 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-hr urinary (U-) normetanephrine levels, clinic and ambulatory heart rate (HR), HR variability (HRV), arterial stiffness as indexed by pulse wave velocity (PWV), and systemic vascular resistance (SVR) compared to 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 vs. 56.5±14.1 years, p=0.038) and more likely female (80.0 vs 51.9 %, p=0.047) compared to patients with controlled resistant hypertension. They also had higher U-normetanephrine levels (464.4±250.2 vs. 309.8±147.6 μg/24h, p=0.03), higher clinic HR (77.8±7.7 vs. 68.8±7.6 bpm, p=0.001) and 24-hr ambulatory HR (77.8±7.7 vs 68.8±7.6, p=0.0018), higher PWV (11.8±2.2 vs. 9.4±1.5 m/s, p=0.009), reduced HRV (4.48 vs. 6.11, p=0.03), and higher SVR (3795±1753 vs. 2382±349 dyne·sec·cm5·m2, 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. PMID:25987662

  12. Effects of enalapril maleate on blood pressure, renin-angiotensin-aldosterone system, and peripheral sympathetic activity in essential hypertension.

    Science.gov (United States)

    Cerasola, G; Cottone, S; D'Ignoto, G; Grasso, L; Carone, M B; Carapelle, E; Contorno, A

    1987-01-01

    Recent experimental studies showed that inhibition of angiotensin II synthesis may reduce sympathetic activity as evaluated by plasma catecholamine assay, sharing in the antihypertensive effect of angiotensin converting enzyme (ACE) inhibitors. Fifteen patients with essential hypertension were studied. Blood pressure and heart rate were evaluated both at rest and after stressor laboratory tests, before and four hours after administration of 20 mg of enalapril maleate and on the 14th and 120th days of continued administration. At the same time, blood samples were drawn for determinations of plasma renin activity, ACE, angiotensin II, plasma aldosterone concentration, and plasma norepinephrine levels. Enalapril in a dosage of 20 mg/day significantly and progressively lowered systolic and diastolic blood pressure at rest, with maximal decreases observed on the 120th day of the study period (P less than 0.001). Heart rate at rest and after exercise showed no significant differences throughout the study period. Good blood pressure control was observed during stressor laboratory tests. The greatest impact of blood pressure was observed on the 120th day during dynamic exercise (mean blood pressure from 139 +/- 3.9 to 111.5 +/- 6.3 mmHg; P less than 0.01) and on the 14th day during the cold pressure test (mean blood pressure from 133.3 +/- 3.9 to 111.2 +/- 4.7 mmHg; P less than 0.005). A marked and persistent ACE inhibition and a gradual and progressive decrease of angiotensin II (from 12.42 +/- 2.15 to 5.45 +/- 1.68 pg/ml; P less than 0.005) characterized the humoral activity of enalapril maleate. Moreover, a significant decrease of plasma norepinephrine levels was observed during the follow-up period with maximal reduction on the 120th day (from 311 +/- 34 to 197 +/- 33 pg/ml; P less than 0.01). It has been demonstrated that the pressor effect of angiotensin II was blunted during exercise. Our hemodynamic and humoral results appear to confirm the hypothesis that

  13. 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. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. 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

    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....../UTP-selective receptors. To this aim, we first measured leg blood flow (LBF), mean arterial pressure (MAP), cardiac output , leg arterial-venous (a-v) O(2) difference, plasma ATP and soluble nucleotidase activities during intrafemoral artery infusion of adenosine, AMP, ADP, ATP or UTP in nine healthy males. Comparison...... of the doses of nucleotides and adenosine required for a similar increase in LBF from approximately 0.5 l min(-1) at baseline to approximately 3.5 l min(-1) (without altering MAP but increasing Q significantly) revealed the following rank order of vasoactive potency: ATP (100) = UTP (100) >> adenosine (5...

  15. Evaluation of sympathetic nerve system activity with MIBG. Comparison with heart rate variability

    International Nuclear Information System (INIS)

    Kurata, Chinori; Wakabayashi, Yasushi; Shouda, Sakae; Mikami, Tadashi; Tawarahara, Kei; Sugiyama, Tsuyoshi; Nakano, Tomoyasu; Suzuki, Toshihiko.

    1997-01-01

    Authors attempted to elucidate the relations of plasma concentration of norepinephrine (pNE) and findings of heart rate variability and MIBG myocardial scintigraphy and evaluated cardiac autonomic nervous activity in chronic renal failure. Subjects were 211 patients with various heart diseases (coronary artery lesion, cardiomyopathy, hypertension, diabetes mellitus, renal failure and so on), 60 patients with artificial kidney due to chronic renal failure, 13 of whom were found to have coronary arterial disease by Tl myocardial scintigraphy, and 14 normal volunteers. ECG was recorded with the portable recorder for heart rate variability. Together with collection of blood for pNE measurement, myocardial scintigraphy was done at 15 and 150 min after intravenous administration of 111 MBq of MIBG for acquisition of early and delayed, respectively, images of the frontal breast. Accumulation at and elimination during the time points of MIBG were computed in cps unit. Variability of heart rate was found to have the correlation positive with MIBG delayed accumulation and negative with the elimination, and pNE, negative with heart rate variability and the delayed accumulation and positive with the elimination. Thus cardiac autonomic nervous abnormality was suggested to occur before uremic cardiomyopathy. (K.H.)

  16. Sympathetic Activity, Assessed by Power Spectral Analysis of Heart Rate Variability, in White-Coat, Masked and Sustained Hypertension Versus True Normotension

    Czech Academy of Sciences Publication Activity Database

    Fagard, R.H.; Stolarz, K.; Kuznetsova, T.; Seidlerová, J.; Tikhonoff, V.; Grodzicki, T.; Nikitin, Y.; Filipovský, J.; Peleška, Jan; Casiglia, E.; Thijs, L.; Staessen, J.A.; Kawecka-Jaszcz, K.

    2007-01-01

    Roč. 25, č. 11 (2007), s. 2280-2285 ISSN 0263-6352 Institutional research plan: CEZ:AV0Z10300504 Keywords : heart rate variability * masked hypertension * power spectral analysis * sympathetic activity * white-coat hypertension Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 4.364, year: 2007

  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. Copyright © 2016 the American Physiological Society.

  18. 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.

  19. Reflex sympathetic dystrophy.

    Science.gov (United States)

    Miller, Ruth L S

    2003-01-01

    Reflex sympathetic dystrophy, also known as complex regional pain syndrome type I, is a multisymptom syndrome usually affecting one or more extremities. It is inadequately understood and, therefore, often frustrating to treat. This article presents a case study of a 23-year career nurse who developed reflex sympathetic dystrophy of the left knee. It also reviews the rationale for reflex sympathetic dystrophy, treatment, and life-care planning for a patient with reflex sympathetic dystrophy.

  20. Activation in the hypothalamic-pituitary-adrenocortical axis and sympathetic nervous system in women with carpal tunnel syndrome.

    Science.gov (United States)

    Fernández-de-Las-Peñas, César; Díaz-Rodríguez, Lourdes; Salom-Moreno, Jaime; Galiano-Castillo, Noelia; Valverde-Herreros, Lis; Martínez-Martín, Javier; Pareja, Juan A

    2014-08-01

    The aim of this study is to investigate the differences in salivary cortisol (hypothalamic-pituitary-adrenocortical [HPA] axis), α-amylase activity (sympathetic nervous system [SNS]), and immunoglobulin A (IgA; immune system) concentrations between women with carpal tunnel syndrome (CTS) and healthy women. A cross-sectional study. Activation of HPA, SNS, and immune system in CTS has not been clearly determined. One hundred two women (age: 45 ± 7 years) with electrodiagnostic and clinical diagnosis of CTS and 102 matched healthy women. The intensity of the pain was assessed with a Numerical Pain Rating Scale (0-10), and disability was determined with Boston Carpal Tunnel Questionnaire. Salivary cortisol concentration, α-amylase activity, salivary flow rate, and IgA concentration were collected from nonstimulated saliva. Women with CTS exhibited lower salivary flow rate (P  0.2) were found between groups as a total. Women with severe CTS exhibited lower salivary flow rate (P < 0.001), higher α-amylase activity (P = 0.002), and higher cortisol concentration (P = 0.03) than healthy women and than those with minimal/moderate CTS (P < 0.05). Within women with CTS, significant positive associations between α-amylase activity and the intensity of pain were found: the highest the level of pain, the higher the α-amylase activity, i.e., higher SNS activation. These results suggest that women with severe CTS exhibit changes in activation in the HPA axis and SNS but not in the humoral immune system. Activation of the SNS was associated with the intensity of pain. Future studies are needed to elucidate the direction of this relationship. Wiley Periodicals, Inc.

  1. 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

    International Nuclear Information System (INIS)

    Conte, Elio; Federici, Antonio; Zbilut, Joseph P.

    2009-01-01

    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.

  2. Obesity depresses baroreflex control of renal sympathetic nerve activity and heart rate in Sprague Dawley rats: role of the renal innervation.

    Science.gov (United States)

    Khan, S A; Sattar, M Z A; Abdullah, N A; Rathore, H A; Abdulla, M H; Ahmad, A; Johns, E J

    2015-07-01

    This study investigated the role of the renal innervation in arterial and cardiopulmonary baroreflex regulation of renal sympathetic nerve activity (RSNA) and heart rate (HR) in rats fed a high-fat diet to induce obesity. Rats received either a normal (12% kcal) or high (45% kcal) fat diet for 60 days. On day 61, rats were anesthetized and prepared for recording left RSNA. In one group, the renal nerves remained intact, while in the other, both kidneys were denervated. Baroreflex gain curves for RSNA and HR were generated by increasing and decreasing blood pressure. Low-pressure baroreceptors were challenged by infusing a saline load. Mean blood pressure was 135 mmHg in the fat-fed and 105 mmHg (P baroreflex sensitivities were reduced by 73 and 72% (both P baroreflexes which was dependent on an intact renal innervation. This suggests that in obese states neural signals arising from the kidney contribute to a deranged autonomic control. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  3. Age-related weakening of baroreflex-mediated sympathetic activity in spontaneously hypertensive rats in response to blood pressure reduction.

    Science.gov (United States)

    Prados, P; Santa, T; Fukushima, T; Homma, H; Kasai, C; Martin, M A; del Castillo, B; Imai, K

    1998-09-01

    Nicardipine, a dihydropyridine type calcium channel blocker, was infused into 4-, 6-, and 23-wk-old spontaneously hypertensive (SH) and age-matched normotensive Wistar-Kyoto (WKY) rats (under sodium thiobutabarbital anesthesia and ventilation, n = 4) through the left femoral vein, resulting in the reduction of blood pressure. In each rat, mean arterial blood pressure, heart rate, and the concentration of plasma catecholamines (CAs), norepinephrine (NE), and epinephrine (E) were concomitantly determined, and the correlations between these three variables were studied. During the infusion of nicardipine, the plasma concentration of CAs was measured with an automatic detection system in blood samples collected from the right femoral artery of each rat. The reduction in blood pressure induced by nicardipine brought about an increase in plasma CA levels. The blood pressure correlated well with the logarithm of plasma NE or E concentration according to the formula Y= -alpha log (X) + m (Y, blood pressure; X, concentration of plasma NE or E; a, slope; and m, intercept). The slopes (as) of 6-wk-old and 23-wk-old SH rats were significantly greater than those of aged-matched WKY rats, meaning that the increment in plasma CAs in response to a decrease in blood pressure was smaller in SH than in WKY rats of similar ages. However, no significant differences were found between the as of 4-wk-old SH and WKY rats. We conclude that the increment in the baroreflex-mediated sympathetic activity in response to a drop in blood pressure induced by nicardipine is similar or greater in prehypertensive SH than in normotensive WKY 4-wk-old rats, while the increment becomes smaller in SH rats with the onset of hypertension (6-wk-old rats), and is much less in fully hypertensive adult (23-wk-old) SH rats than in age-matched WKY rats. On the basis of these findings and previous data obtained by neurography, we conclude that plasma CAs can be used to evaluate baroreflex-mediated sympathetic

  4. Sympathetic neurotransmitters promote the process of recellularization in decellularized liver matrix via activating the IL-6/Stat3 pathway.

    Science.gov (United States)

    Wen, Xudong; Huan, Hongbo; Wang, Xiaojun; Chen, Xuejiao; Wu, Lili; Zhang, Yujun; Liu, Weihui; Bie, Ping; Xia, Feng

    2016-11-04

    Recellularized liver, as an approach for hepatic tissue engineering, is an effective alternative to orthotopic liver transplantation for end-stage hepatic failure. When compared with normal liver, recellularized liver has a disparity in hepatocyte viability and function, owing to the difficulty of fully simulating the microenvironment of liver. Although the sympathetic nervous system (SNS) is considered an important constituent of liver function, few studies have examined the effect of the SNS on hepatic tissue engineering. It is imperative to explore the regulation of the SNS on a tissue-like configuration to obtain an intact recellularized liver with better hepatic function. We have observed that various subtypes of adrenergic receptors (ARs) are expressed on the hepatocyte membrane. Salbutamol, an agonist of β2-AR, promoted cell proliferation, albumin secretion and urea synthesis in the recellularized liver. Cytokines were screened in isoprenaline/salbutamol-treated recellularized liver, and the expression of IL-6 was significantly increased. Isoprenaline or salbutamol especially promoted the expression of Stat 3 and phosphorylated Stat 3, contributing to the activation of IL-6/Stat 3 signalling in promoting hepatocyte proliferation and recellularized liver function. This study suggests that activation of β2-AR accelerated hepatocyte proliferation and improved recellularized liver function by mediating the IL-6/Stat 3 signalling pathway, indicating that nervous system regulation may be an essential component contributing to the complexity of recellularized liver in tissue engineering.

  5. Sympathetic actions on the skeletal muscle.

    Science.gov (United States)

    Roatta, Silvestro; Farina, Dario

    2010-01-01

    The sympathetic nervous system (SNS) modulates several functions in skeletal muscle fibers, including metabolism, ionic transport across the membrane, and contractility. These actions, together with the sympathetic control of other organ systems, support intense motor activity. However, some SNS actions on skeletal muscles may not always be functionally advantageous. Implications for motor control and sport performance are discussed.

  6. Effects of nicorandil on cardiac sympathetic nerve activity after reperfusion therapy in patients with first anterior acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-03-01

    Ischaemic preconditioning (PC) is a cardioprotective phenomenon in which short periods of myocardial ischaemia result in resistance to decreased contractile dysfunction during a subsequent period of sustained ischaemia. Nicorandil, an ATP-sensitive potassium channel opener, can induce PC effects on sympathetic nerves during myocardial ischaemia. However, its effects on cardiac sympathetic nerve activity (CSNA) and left ventricular remodelling have not been determined. In this study, we sought to determine whether nicorandil administration improves CSNA in patients with acute myocardial infarction (AMI). We studied 58 patients with first anterior AMI, who were randomly assigned to receive nicorandil (group A) or isosorbide dinitrate (group B) after primary coronary angioplasty. The nicorandil or isosorbide dinitrate was continuously infused for >48 h. The extent score (ES) was determined from {sup 99m}Tc-pyrophosphate scintigraphy, and the total defect score (TDS) was determined from {sup 201}Tl scintigraphy 3-5 days after primary angioplasty. The left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) were determined by left ventriculography 2 weeks later. The delayed heart/mediastinum count (H/M) ratio, delayed TDS and washout rate (WR) were determined from {sup 123}I-meta-iodobenzylguanidine (MIBG) images 3 weeks later. The left ventriculography results were re-examined 6 months after treatment. Fifty patients originally enrolled in the trial completed the entire protocol. After treatment, no significant differences were observed in ES or left ventricular parameters between the two groups. However, in group A (n=25), the TDSs determined from {sup 201}Tl and {sup 123}I-MIBG were significantly lower (26{+-}6 vs 30{+-}5, P<0.01, and 32{+-}8 vs 40{+-}6, P<0.0001, respectively), the H/M ratio significantly higher (1.99{+-}0.16 vs 1.77{+-}0.30, P<0.005) and the WR significantly lower (36%{+-}8% vs 44%{+-}12%, P<0.005) than in group B

  7. Sympathetic nervous system activity measured by skin conductance quantifies the challenge of walking adaptability tasks after stroke.

    Science.gov (United States)

    Clark, David J; Chatterjee, Sudeshna A; McGuirk, Theresa E; Porges, Eric C; Fox, Emily J; Balasubramanian, Chitralakshmi K

    2018-02-01

    Walking adaptability tasks are challenging for people with motor impairments. The construct of perceived challenge is typically measured by self-report assessments, which are susceptible to subjective measurement error. The development of an objective physiologically-based measure of challenge may help to improve the ability to assess this important aspect of mobility function. The objective of this study to investigate the use of sympathetic nervous system (SNS) activity measured by skin conductance to gauge the physiological stress response to challenging walking adaptability tasks in people post-stroke. Thirty adults with chronic post-stroke hemiparesis performed a battery of seventeen walking adaptability tasks. SNS activity was measured by skin conductance from the palmar surface of each hand. The primary outcome variable was the percent change in skin conductance level (ΔSCL) between the baseline resting and walking phases of each task. Task difficulty was measured by performance speed and by physical therapist scoring of performance. Walking function and balance confidence were measured by preferred walking speed and the Activities-specific Balance Confidence Scale, respectively. There was a statistically significant negative association between ΔSCL and task performance speed and between ΔSCL and clinical score, indicating that tasks with greater SNS activity had slower performance speed and poorer clinical scores. ΔSCL was significantly greater for low functioning participants versus high functioning participants, particularly during the most challenging walking adaptability tasks. This study supports the use of SNS activity measured by skin conductance as a valuable approach for objectively quantifying the perceived challenge of walking adaptability tasks in people post-stroke. Published by Elsevier B.V.

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

    International Nuclear Information System (INIS)

    Nanjo, Shuji; Fujimoto, Shinichiro; Yamashiro, Yoshihiro

    2009-01-01

    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, 123 I-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)

  9. [Mechanisms of sympathetic activity in rats exposed to different patterns of hypoxia and the correlation with blood pressure].

    Science.gov (United States)

    He, Ruoxi; Su, Xiaoli; Xiang, Yonghong; Hu, Chengping; Luo, Yingquan

    2011-10-01

    To observe the effects of two different hypoxia patterns on blood pressure and the underlying mechanisms. Eighteen male SD rats were randomly divided into three groups: the intermittent hypoxia group (IH group), the continuous hypoxia group (CH group) and the normal control group (NC group). The rats of the IH and CH group were subjected to intermittent hypoxia (7 h/d) and continuous hypoxia (7 h/d) for 42 days respectively. The NC group rats were untreated. The levels of arteria caudilis systolic pressure (ACSP) were measured with noninvasive rats arteria caudilis gauge before the experiment, at the end of 3rd, 6th week of the experiment. The concentrations of norepinephrine (NE) in serum and neuropeptide Y (NPY) in plasma were respectively measured by enzyme-linked-immunosorbent assay (ELISA) and radioimmunoassay. The contents of malondialdehyde (MDA) and the ability of inhibiting hydroxyl free radical in serum were analyzed by thiobarbituric acid colorimetric analysis (TBAR) at the end of 6th week. At the end of 3rd week, the levels of ACSP were considerably higher than those before the treatment (P0.05). The levels of NE, NPY and MDA were positively related with ACSP (r=0.873, Phigh blood pressure, which may be related to the sympathetic over-activity and the oxidative stress.

  10. Perceived stress status and sympathetic nervous system activation in young male patients with coronary artery disease in China.

    Science.gov (United States)

    Yang, You; Bi, Minghui; Xiao, Lin; Chen, Qiaopin; Chen, Wenron; Li, Wensheng; Wu, Yanxian; Hu, Yunzhao; Huang, Yuli

    2015-11-01

    Young Chinese male adults have faced increasing psychological stress. Whether this is associated with the increased risk of coronary artery disease (CAD) in young Chinese males remains unclear. This study aimed to evaluate the correlation and underlying mechanisms of perceived stress and CAD in young male patients. A total of 178 male patients diagnosed as young CAD (aged ≤ 55 years) by coronary angiography (CAG) were enrolled, and 181 age-matched non-CAD individuals were set as control group. Traditional cardiovascular risk factors and levels of epinephrine and norepinephrine were measured, and perceived stress status was accessed by Perceived Stress Scale (PSS). The PSS score was correlated with levels of epinephrine (r=0.45), norepinephrine (r=0.41), high-sensitivity C-reactive protein (hs-CRP) (r=0.38, pPSS score (OR, 1.81; 95%CI, 1.23-2.66) were independently correlated with CAD in young patients. The association between PSS score and risk of CAD become insignificant (OR, 1.43; 95%CI, 0.96-2.13) when further adjusted for the levels of epinephrine and norepinephrine. After adjustment for multiple cardiovascular risk factors, high perceived stress was an independent risk factor for CAD in young Chinese male patients. Abnormal activation of the sympathetic nervous system may play an important role linking perceived stress with the risk of CAD. Copyright © 2015 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  11. 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 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.

  12. A Proteomic Evaluation of Sympathetic Activity Biomarkers of the Hypothalamus-Pituitary-Adrenal Axis by Western Blotting Technique Following Experimental Traumatic Brain Injury.

    Science.gov (United States)

    Toklu, Hale Zerrin; Sakarya, Yasemin; Tümer, Nihal

    2017-01-01

    Endocrine disorders and autonomic dysfunction are common paradigms following traumatic brain injury (TBI). Alterations in the hypothalamus-pituitary-adrenal (HPA) axis following TBI may result in impaired vasopressor response, energy imbalance, fatigue, depression, or neurological disorders. Autonomic dysfunction is a common disorder following TBI. The sympathetic activity markers on HPA axis can be measured by Western blot protein analysis. Tyrosine hydroxylase, dopamine beta hydroxylase are the key enzymes for the synthesis of norepinephrine; and neuropeptide Y (NPY) is the peptide that is co-stored and co-released with norepinephrine. Thus, the present chapter reviews the experimental protocols for Western blot protein analysis for the measurement of biomarkers that indicate sympathetic activity in brain regions (hypothalamus, pituitary, cerebral cortex, and cerebellum) following TBI.

  13. Regulation of the renal sympathetic nerves in heart failure

    Directory of Open Access Journals (Sweden)

    Rohit eRamchandra

    2015-08-01

    Full Text Available Heart failure (HF is a serious debilitating condition with poor survival rates and an increasing level of prevalence. Heart failure is associated with an increase in renal norepinephrine spillover, which is an independent predictor of mortality in HF patients. The excessive sympatho-excitation that is a hallmark of heart failure has long-term effects that contribute to disease progression. An increase in directly recorded renal sympathetic nerve activity has also been recorded in animal models of heart failure. This review will focus on the mechanisms controlling sympathetic nerve activity to the kidney during normal conditions and alterations in these mechanisms during heart failure. In particular the roles of afferent reflexes and central mechanisms will be discussed.

  14. Sympathetic nervous system activation reduces contraction-induced rapid vasodilation in the leg of humans independent of age.

    Science.gov (United States)

    Hughes, William E; Kruse, Nicholas T; Casey, Darren P

    2017-07-01

    Contraction-induced rapid vasodilation is attenuated similarly in the upper and lower limbs of older adults. In the forearm, this attenuation is in part due to a greater sympathetic vasoconstriction. We examined whether the age-related reduction in contraction-induced vasodilation in the leg is also due to a sympathetic vasoconstrictive mechanism. Thirteen young (24 ± 1 yr) and twelve older adults (67 ± 1 yr) performed single-leg knee extension at 20 and 40% of work-rate maximum (WR max ) during control and cold-pressor test (CPT) conditions. Femoral artery diameter and blood velocity were measured using Doppler ultrasound. Vascular conductance (VC; ml·min -1 ·mmHg -1 ) was calculated using blood flow (ml/min) and mean arterial pressure (mmHg). Peak (ΔVC from baseline) and total VC were blunted in older adults during control conditions across exercise intensities ( P ROV). Within the forearm, this attenuation is partially due to enhanced sympathetic vasoconstriction. In the current study, we found that sympathetic vasoconstriction reduces contraction-induced ROV within the leg of both young and older adults, with the magnitude of change being similar between age groups. Our current results suggest that age-related attenuations in contraction-induced ROV within the leg are not fully explained by a sympathetic vasoconstrictor mechanism. Copyright © 2017 the American Physiological Society.

  15. Heart rate response to blood pressure variations: sympathetic activation versus baroreflex response in patients with end-stage renal disease.

    Science.gov (United States)

    Sapoznikov, Dan; Dranitzki Elhalel, Michal; Rubinger, Dvora

    2013-01-01

    Continuous systolic blood pressure (SBP) and interbeat intervals (IBI) recordings reveal sequences of consecutive beats in which SBP and heart rate change in opposite direction, representing negative feedback baroreflex mechanisms, as well as sequences in which SBP and heart rate change in the same direction (non-baroreflex), believed to represent feedforward control mechanisms. The present study was undertaken to assess the relationship between baroreflex and non-baroreflex sequences in end stage renal insufficiency. Continuous beat-to-beat SBP and IBI monitoring was performed in patients on chronic hemodialysis (HD, n=72), in age-matched patients after renal transplantation (TX, n=41) and healthy (control) individuals (C, n=34). The proportion of baroreflex and nonbaroreflex episodes and the b coefficients (the regression line slope of SBP-IBI correlation) were determined using a newly developed 1 minute sliding window method, the classical sequence technique and the "Z" coefficient method. Analysis using the 1 minute sliding window showed an increased proportion of baroreflex episodes in controls and HD, and predominance of nonbaroreflex episodes in TX. An increased proportion of nonbaroreflex episodes in TX patients relative to HD was also revealed by the "Z" method. Baroreflex and nonbaroreflex b coefficients obtained by all methods were markedly decreased in HD. This alteration was reversed at least partly in TX. In HD, both baroreflex and nonbaroreflex b coefficients were inversely correlated to age and CRP levels; in TX, the nonbaroreflex b coefficient was influenced by the type of calcineurin inhibitor. Renal status affects the contribution of baroreflex and nonbaroreflex mechanisms and the strength of SBP-IBI relationship. The predominant contribution of nonbaroreflex mechanisms in TX may be suggestive of enhanced central sympathetic control. Our data may be relevant for understanding of the pathogenesis and selection of appropriate treatment of post

  16. 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...

  17. Sympathetic skin responses in reflex sympathetic dystrophy.

    Science.gov (United States)

    Bolel, K; Hizmetli, S; Akyüz, A

    2006-07-01

    This study was performed to determine the utility of sympathetic skin response (SSR) in evaluating the sympathetic function and to follow up the effects of sympathetic blockade in reflex sympathetic dystrophy (RSD). Thirty patients having RSD with upper extremity involvement were randomly divided into two groups. Besides medical therapy and exercise, physical therapy agents were applied to both the groups. In addition to this treatment protocol, stellar ganglion blockade was done by diadynamic current in Group II. The normal sides of the patients were used for the control group. SSRs were measured in all the patients before and after the therapy. The amplitude was found to be increased and the latency was found to be decreased in the affected side in both the groups before the therapy. After the therapy, the amplitude was decreased and latency was increased in both the groups. But, the differences in amplitude (P = 0.001) and latency (P = 0.002) before and after the therapy were significantly higher in Group II. (Before the treatment, SSRs were significantly different between the normal and the affected sides in both the groups. The observed change in SSRs after the treatment was higher in Group II.) It was concluded that, SSR can be a useful and noninvasive method in diagnosing the sympathetic dysfunction in RSD and can be used for evaluating the response to sympathetic blockade and other treatment modalities.

  18. Jugular venous overflow of noradrenaline from the brain: a neurochemical indicator of cerebrovascular sympathetic nerve activity in humans

    DEFF Research Database (Denmark)

    Mitchell, D.A.; Lambert, G.; Secher, Niels H.

    2009-01-01

    )) overflow rates were measured. These measurements were also made following ganglion blockade (trimethaphan, n = 6), central sympathetic inhibition (clonidine, n = 4) and neuronal noradrenaline uptake blockade (desipramine, n = 13) and in a group of patients (n = 9) with pure autonomic failure (PAF...... = 0.3). Neuronal noradrenaline uptake block with desipramine lowered the transcranial plasma extraction of tritiated noradrenaline (P = 0.001). The PAF patients had 77% lower brain noradrenaline spillover than healthy recruits (P = 0.06), indicating that in them sympathetic nerve degeneration extended...

  19. Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

    International Nuclear Information System (INIS)

    Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke

    2000-01-01

    Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5±6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33±0.22 in chronic heart failure class I, 2.50±0.34 in class II, 1.95±0.61 in class III, and 1.39±0.29 in class IV (p<0.05). %WR was 24.8±12.8% in chronic heart failure class I, 23.3±10.2% in class II, 49.2±24.5% in class III, and 66.3±26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

  20. Sleep-Disordered Breathing Exacerbates Muscle Vasoconstriction and Sympathetic Neural Activation in Patients with Systolic Heart Failure.

    Science.gov (United States)

    Lobo, Denise M L; Trevizan, Patricia F; Toschi-Dias, Edgar; Oliveira, Patricia A; Piveta, Rafael B; Almeida, Dirceu R; Mady, Charles; Bocchi, Edimar A; Lorenzi-Filho, Geraldo; Middlekauff, Holly R; Negrão, Carlos E

    2016-11-01

    Sleep-disordered breathing (SDB) is common in patients with heart failure (HF), and hypoxia and hypercapnia episodes activate chemoreceptors stimulating autonomic reflex responses. We tested the hypothesis that muscle vasoconstriction and muscle sympathetic nerve activity (MSNA) in response to hypoxia and hypercapnia would be more pronounced in patients with HF and SDB than in patients with HF without SDB (NoSBD). Ninety consecutive patients with HF, New York Heart Association functional class II-III, and left ventricular ejection fraction ≤40% were screened for the study. Forty-one patients were enrolled: NoSDB (n=13, 46 [39-53] years) and SDB (n=28, 57 [54-61] years). SDB was characterized by apnea-hypopnea index ≥15 events per hour (polysomnography). Peripheral (10% O 2 and 90% N 2 , with CO 2 titrated) and central (7% CO 2 and 93% O 2 ) chemoreceptors were stimulated for 3 minutes. Forearm and calf blood flow were evaluated by venous occlusion plethysmography, MSNA by microneurography, and blood pressure by beat-to-beat noninvasive technique. Baseline forearm blood flow, forearm vascular conductance, calf blood flow, and calf vascular conductance were similar between groups. MSNA was higher in the SDB group. During hypoxia, the vascular responses (forearm blood flow, forearm vascular conductance, calf blood flow, and calf vascular conductance) were significantly lower in the SDB group compared with the NoSDB group (Phypoxia (P=0.024) and tended to be higher to hypercapnia (P=0.066) in the SDB group. Patients with HF and SDB have more severe muscle vasoconstriction during hypoxia and hypercapnia than HF patients without SDB, which seems to be associated with endothelial dysfunction and, in part, increased MSNA response. © 2016 American Heart Association, Inc.

  1. Abnormal central control underlies impaired baroreflex control of heart rate and sympathetic nerve activity in female Lewis polycystic kidney rats.

    Science.gov (United States)

    Salman, Ibrahim M; Phillips, Jacqueline K; Ameer, Omar Z; Hildreth, Cara M

    2015-07-01

    Why baroreflex dysfunction occurs in females with chronic kidney disease is unknown. We therefore aimed to examine whether temporal changes in baroreflex control of heart rate (HR) and renal sympathetic nerve activity (RSNA) occur in female Lewis polycystic kidney (LPK) rats and whether this is associated with any changes in afferent, central or efferent processing of the reflex pathway. Using urethane-anaesthetized juvenile and adult LPK and Lewis control rats (n = 40), baroreflex-mediated changes in HR, RSNA and aortic depressor nerve activity (ADNA) were examined. Reflex changes to aortic depressor and vagal efferent nerve stimulation were also determined. In the juvenile LPK rats, except for a slight reduction in the gain of the normalized HR and RSNA baroreflex function curves, no difference in baroreflex control of HR, RSNA or ADNA was observed. Responses to aortic depressor and vagal efferent nerve stimulation were also comparable. In the adult hypertensive LPK rats, the range of both HR (35 ± 8 vs. 78 ± 9  bpm, P ≤ 0.05 LPK vs. Lewis) and RSNA (60 ± 7 vs. 80 ± 3%, P ≤ 0.05 LPK vs. Lewis) was also reduced. This was not associated with any change in the ADNA baroreflex function curves or reflex HR responses to vagal efferent nerve stimulation, but was associated with a reduction in the reflex bradycardic (-21 ± 4 vs. -34 ± 8 bpm, P baroreflex dysfunction results from impaired central processing of the reflex.

  2. 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....... Self-reported snoring was associated with gender (males showed higher prevalence than females, p ... with tobacco consumption (p = 0.08). No associations were found between snoring and fasting glucose, plasma lipids, plasma epinephrine or in the use of antihypertensive medication. In multivariate analysis, with forced entry of gender, BMI, physical activity, alcohol and tobacco consumption, the relation...

  3. Hypothalamic-Pituitary-Adrenal and Sympathetic Nervous System Activity and Children's Behavioral Regulation

    Science.gov (United States)

    Lisonbee, Jared A.; Pendry, Patricia; Mize, Jacquelyn; Gwynn, Eugenia Parrett

    2010-01-01

    Self-regulation ability is an important component of children's academic success. Physiological reactivity may relate to brain activity governing attention and behavioral regulation. Saliva samples collected from 186 preschool children (101 boys, mean age = 53 months, 34% minority) before and after a series of mildly challenging games and again 30…

  4. Trigger point-related sympathetic nerve activity in chronic sciatic leg pain: a case study.

    Science.gov (United States)

    Skorupska, Elżbieta; Rychlik, Michał; Pawelec, Wiktoria; Bednarek, Agata; Samborski, Włodzimierz

    2014-10-01

    Sciatica has classically been associated with irritation of the sciatic nerve by the vertebral disc and consequent inflammation. Some authors suggest that active trigger points in the gluteus minimus muscle can refer pain in similar way to sciatica. Trigger point diagnosis is based on Travel and Simons criteria, but referred pain and twitch response are significant confirmatory signs of the diagnostic criteria. Although vasoconstriction in the area of a latent trigger point has been demonstrated, the vasomotor reaction of active trigger points has not been examined. We report the case of a 22-year-old Caucasian European man who presented with a 3-year history of chronic sciatic-type leg pain. In the third year of symptoms, coexistent myofascial pain syndrome was diagnosed. Acupuncture needle stimulation of active trigger points under infrared thermovisual camera showed a sudden short-term vasodilatation (an autonomic phenomenon) in the area of referred pain. The vasodilatation spread from 0.2 to 171.9 cm(2) and then gradually decreased. After needling, increases in average and maximum skin temperature were seen as follows: for the thigh, changes were +2.6°C (average) and +3.6°C (maximum); for the calf, changes were +0.9°C (average) and +1.4°C (maximum). It is not yet known whether the vasodilatation observed was evoked exclusively by dry needling of active trigger points. The complex condition of the patient suggests that other variables might have influenced the infrared thermovision camera results. We suggest that it is important to check if vasodilatation in the area of referred pain occurs in all patients with active trigger points. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. 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

    . Self-reported snoring was associated with gender (males showed higher prevalence than females, p pressure, glucose tolerance test (p ...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

  6. Bradykinin receptor blockade restores the baroreflex control of renal sympathetic nerve activity in cisplatin-induced renal failure rats.

    Science.gov (United States)

    Abdulla, M H; Duff, M; Swanton, H; Johns, E J

    2016-11-01

    This study investigated the effect of renal bradykinin B1 and B2 receptor blockade on the high- and low-pressure baroreceptor reflex regulation of renal sympathetic nerve activity (RSNA) in rats with cisplatin-induced renal failure. Cisplatin (5 mg/kg) or saline was given intraperitoneally 4 days prior to study. Following chloralose/urethane anaesthesia, rats were prepared for measurement of mean arterial pressure (MAP), heart rate and RSNA and received intrarenal infusions of either Lys-[des-Arg 9 , Leu 8 ]-bradykinin (LBK), a bradykinin B1 receptor blocker, or bradyzide (BZ), a bradykinin B2 receptor blocker. RSNA baroreflex gain curves and renal sympatho-inhibitory responses to volume expansion (VE) were obtained. In the control and renal failure groups, basal MAP (89 ± 3 vs. 80 ± 8 mmHg) and RSNA (2.0 ± 0.3 vs. 1.7 ± 0.6 μV.s) were similar but HR was lower in the latter group (331 ± 8 vs. 396 ± 9 beats/min). The baroreflex gain for RSNA in the renal failure rats was 39% (P renal failure rats. Intrarenal LBK infusion in the renal failure rats normalized the VE induced renal sympatho-inhibition whereas BZ only partially restored the response. These findings suggest that pro-inflammatory bradykinin acting at different receptors within the kidney generates afferent neural signals which impact differentially within the central nervous system on high- and low-pressure regulation of RSNA. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  7. 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.

  8. 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.

  9. Endoplasmic reticulum stress increases brain MAPK signaling, inflammation and renin-angiotensin system activity and sympathetic nerve activity in heart failure.

    Science.gov (United States)

    Wei, Shun-Guang; Yu, Yang; Weiss, Robert M; Felder, Robert B

    2016-10-01

    We previously reported that endoplasmic reticulum (ER) stress is induced in the subfornical organ (SFO) and the hypothalamic paraventricular nucleus (PVN) of heart failure (HF) rats and is reduced by inhibition of mitogen-activated protein kinase (MAPK) signaling. The present study further examined the relationship between brain MAPK signaling, ER stress, and sympathetic excitation in HF. Sham-operated (Sham) and HF rats received a 4-wk intracerebroventricular (ICV) infusion of vehicle (Veh) or the ER stress inhibitor tauroursodeoxycholic acid (TUDCA, 10 μg/day). Lower mRNA levels of the ER stress biomarkers GRP78, ATF6, ATF4, and XBP-1s in the SFO and PVN of TUDCA-treated HF rats validated the efficacy of the TUDCA dose. The elevated levels of phosphorylated p44/42 and p38 MAPK in SFO and PVN of Veh-treated HF rats, compared with Sham rats, were significantly reduced in TUDCA-treated HF rats as shown by Western blot and immunofluorescent staining. Plasma norepinephrine levels were higher in Veh-treated HF rats, compared with Veh-treated Sham rats, and were significantly lower in the TUDCA-treated HF rats. TUDCA-treated HF rats also had lower mRNA levels for angiotensin converting enzyme, angiotensin II type 1 receptor, tumor necrosis factor-α, interleukin-1β, cyclooxygenase-2, and NF-κB p65, and a higher mRNA level of IκB-α, in the SFO and PVN than Veh-treated HF rats. These data suggest that ER stress contributes to the augmented sympathetic activity in HF by inducing MAPK signaling, thereby promoting inflammation and renin-angiotensin system activity in key cardiovascular regulatory regions of the brain.

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

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    sympathetic vasoconstrictor reflexes are blocked. Blood flow has been measure by the local 133Xe-technique. The results indicate the presence of spinal as well as supraspinal sympathetic vasoconstrictor reflexes to human peripheral tissues. Especially is emphasized the presence of a local sympathetic veno......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...

  11. 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

  12. Acute effects of angiotensin-converting enzyme inhibition versus angiotensin II receptor blockade on cardiac sympathetic activity in patients with heart failure.

    Science.gov (United States)

    Azevedo, Eduardo R; Mak, Susanna; Floras, John S; Parker, John D

    2017-10-01

    The beneficial effects of angiotensin-converting enzyme (ACE) inhibitors and angiotensin II (ANG II) receptor antagonists in patients with heart failure secondary to reduced ejection fraction (HFrEF) are felt to result from prevention of the adverse effects of ANG II on systemic afterload and renal homeostasis. However, ANG II can activate the sympathetic nervous system, and part of the beneficial effects of ACE inhibitors and ANG II antagonists may result from their ability to inhibit such activation. We examined the acute effects of the ACE inhibitor captopril (25 mg, n = 9) and the ANG II receptor antagonist losartan (50 mg, n = 10) on hemodynamics as well as total body and cardiac norepinephrine spillover in patients with chronic HFrEF. Hemodynamic and neurochemical measurements were made at baseline and at 1, 2, and 4 h after oral dosing. Administration of both drugs caused significant reductions in systemic arterial, cardiac filling, and pulmonary artery pressures ( P < 0.05 vs. baseline). There was no significant difference in the magnitude of those hemodynamic effects. Plasma concentrations of ANG II were significantly decreased by captopril and increased by losartan ( P < 0.05 vs. baseline for both). Total body sympathetic activity increased in response to both captopril and losartan ( P < 0.05 vs. baseline for both); however, there was no change in cardiac sympathetic activity in response to either drug. The results of the present study do not support the hypothesis that the acute inhibition of the renin-angiotensin system has sympathoinhibitory effects in patients with chronic HFrEF. Copyright © 2017 the American Physiological Society.

  13. 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.)

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

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    sympathetic vasoconstrictor reflexes are blocked. Blood flow has been measure by the local 133Xe-technique. The results indicate the presence of spinal as well as supraspinal sympathetic vasoconstrictor reflexes to human peripheral tissues. Especially is emphasized the presence of a local sympathetic veno......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...... skeletal muscle, cutaneous and subcutaneous tissues of the limbs indicate that the situation is more complex. Measurements have been carried out during acute as well as chronic sympathetic denervation. Spinal sympathetic reflex mechanisms have been evaluated in tetraplegic patients, where supraspinal...

  15. Prediction of cardiac sympathetic nerve activity and cardiac functional outcome after treatment in patients with dilated cardiomyopathy. Examination using dobutamine gated blood pool scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu; Toyama, Takuji; Iwasaki, Tsutomu; Suzuki, Tadashi [Gunma Univ., Maebashi (Japan). School of Medicine; Hoshizaki, Hiroshi; Oshima, Shigeru; Taniguchi, Koichi; Nagai, Ryozo

    2000-07-01

    This study evaluated whether dobutamine gated blood pool scintigraphy can predict improvement of cardiac sympathetic nerve activity and cardiac function. Sixteen patients (10 men and 6 women, mean age 59{+-}13 years) with dilated cardiomyopathy underwent dobutamine gated blood pool scintigraphy to measure left ventricular ejection fraction (LVEF) using tracer at 0, 5, 10 and 15 {mu}g/kg/min before treatment. Patients were divided into good responders (LVEF increase {>=}15%) 8 patients (GR Group) and poor responders (LVEF increase <15%) 8 patients (PR Group) after treatment with {beta}-blocker or amiodarone with a background treatment of digitalis, diuretics and angiotensin converting enzyme inhibitor. I-123 metaiodobenzylguanidine (MIBG) imaging to evaluate cardiac sympathetic nerve activity and echocardiography were performed before and at one year after treatment. MIBG imaging was obtained 4 hours after tracer injection, and the heart/mediastinum count ratio (H/M ratio) calculated from the anterior planar image and the total defect score (TDS) from the single photon emission computed tomography image. LVEF and left ventricular endo-diastolic dimension (LVDd) were measured by echocardiography and New York Heart Association (NYHA) functional class was evaluated. The GR Group showed TDS decreased from 28{+-}6 to 17{+-}12 (p<0.05), H/M ratio increased from 1.79{+-}0.26 to 2.07{+-}0.32 (p<0.05), LVEF increased from 29{+-}8% to 48{+-}10% (p<0.01), and LVDd decreased from 65{+-}4 mm to 58{+-}5 mm (p<0.05). In contrast, the PR group showed no significant changes in TDS. H/M ratio, LVEF and LVDd. NYHA functional class improved in both groups. The improvement was better in the GR Group than in the PR group. Dobutamine gated blood pool scintigraphy is useful to predict the improvement of the cardiac sympathetic nerve activity and cardiac function, and symptoms after treatment in patients with dilated cardiomyopathy. (author)

  16. Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight

    Science.gov (United States)

    Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Cox, James F.; Zuckerman, Julie H.; Diedrich, Andre; Biaggioni, Italo; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi; hide

    2002-01-01

    Orthostatic intolerance is common when astronauts return to Earth: after brief spaceflight, up to two-thirds are unable to remain standing for 10 min. Previous research suggests that susceptible individuals are unable to increase their systemic vascular resistance and plasma noradrenaline concentrations above pre-flight upright levels. In this study, we tested the hypothesis that adaptation to the microgravity of space impairs sympathetic neural responses to upright posture on Earth. We studied six astronauts approximately 72 and 23 days before and on landing day after the 16 day Neurolab space shuttle mission. We measured heart rate, arterial pressure and cardiac output, and calculated stroke volume and total peripheral resistance, during supine rest and 10 min of 60 deg upright tilt. Muscle sympathetic nerve activity was recorded in five subjects, as a direct measure of sympathetic nervous system responses. As in previous studies, mean (+/- S.E.M.) stroke volume was lower (46 +/- 5 vs. 76 +/- 3 ml, P = 0.017) and heart rate was higher (93 +/- 1 vs. 74 +/- 4 beats min(-1), P = 0.002) during tilt after spaceflight than before spaceflight. Total peripheral resistance during tilt post flight was higher in some, but not all astronauts (1674 +/- 256 vs. 1372 +/- 62 dynes s cm(-5), P = 0.32). No crew member exhibited orthostatic hypotension or presyncopal symptoms during the 10 min of postflight tilting. Muscle sympathetic nerve activity was higher post flight in all subjects, in supine (27 +/- 4 vs. 17 +/- 2 bursts min(-1), P = 0.04) and tilted (46 +/- 4 vs. 38 +/- 3 bursts min(-1), P = 0.01) positions. A strong (r(2) = 0.91-1.00) linear correlation between left ventricular stroke volume and muscle sympathetic nerve activity suggested that sympathetic responses were appropriate for the haemodynamic challenge of upright tilt and were unaffected by spaceflight. We conclude that after 16 days of spaceflight, muscle sympathetic nerve responses to upright tilt are normal.

  17. Scintigraphic evaluation of regional myocardial sympathetic activity in patients with hypertrophic cardiomyopathy. Comparison between asymmetrical hypertrophic cardiomyopathy and apical hypertrophy

    Energy Technology Data Exchange (ETDEWEB)

    Eno, Shin; Takeo, Eiichiro; Sasaki, Satoshi; Matsuda, Keiji; Fujii, Hideaki; Kanazawa, Ikuo [Chugoku Rosai General Hospital, Kure, Hiroshima (Japan)

    1998-02-01

    Using {sup 123}I-MIBG (metaiodobenzylguanidine) and {sup 201}Tl imagings, an examination concerning the relation between the hypertrophic region and its sympathetic nervous function was done. Subjects were 12 normal adults (4 males and 8 females, mean age 61.3 yr), 13 patients with asymmetrical hypertrophic cardiomyopathy (10 males and 3 females, 63.9 yr) and 13 patients with apical hypertrophy (9 males and 4 females, 67.2 yr). The SPECT apparatus was Toshiba two-gated gamma camera GCA 7200A. At 20 min and 3 hr after intravenous injection of 111 MBq of {sup 123}I-MIBG, myocardial SPECT and planar images were obtained with collimator LEHR under following conditions: photoelectric peak 159 KeV, window width 20%, matrix size 64 x 64 (256 x 256 for the planar image), step angle 6deg, 40 sec/step and 180deg for 1 camera. In another day, {sup 201}Tl SPECT and planar imagings were performed 10 min after intravenous injection of 111 MBq of {sup 201}Tl for the photoelectric peak 72 KeV under similar conditions to above. SPECT images were reconstructed using Butterworth filter and Shepp and Logan filter. Images were examined for the defect score, myocardium/mediastinum ratio, whole heart washout rate and regional washout rate. In the asymmetrical hypertrophic myopathy, abnormal sympathetic nerve function was recognized on the regions regardless of their disease severity while in the apical hypertrophy, abnormality was restricted on the apical region. Therefore, the two diseases were found different from each other from the aspect of sympathetic nerve functions. (K.H.)

  18. The effect of a high-carbohydrate meal on postprandial thermogenesis and sympathetic nervous system activity in boys with a recent onset of obesity.

    Science.gov (United States)

    Nagai, Narumi; Sakane, Naoki; Hamada, Taku; Kimura, Tetsuya; Moritani, Toshio

    2005-04-01

    The purpose of the present study was to investigate the thermic effect of food (TEF) and sympathetic nervous system (SNS) activity in obese boys. Ten obese (9.2+/-0.4 years) and 13 lean boys (8.8+/-0.4 years) were examined for energy expenditure and fat oxidation measured via indirect calorimetry for 3 hours after a high-carbohydrate (HC; 70% carbohydrate, 20% fat, and 10% protein) or a high-fat (HF; 20% carbohydrate, 70% fat, and 10% protein) meal served on 2 different days at random. The activity of the SNS was assessed by means of a power spectral analysis of the heart rate variability. The TEF, expressed as a percentage of the consumed energy, was significantly lower in obese boys than in lean boys after the HC meal; however, such a difference was not observed after the HF meal. Multiple regression analysis revealed that obesity was a significant variable contributing to the variances in the TEF induced by the HC meal. Moreover, after the HC meal, the boys with a recent onset of obesity (duration, frequency component of the heart rate variability, an index of thermoregulatory SNS functions, compared with the remaining obese and lean boys. In conclusion, obese boys possessed normal metabolic and sympathetic responses to the HF meal but showed a diminished thermogenic response to the HC meal, especially during the early phase of obesity.

  19. Modulation of pineal activity during the 23rd sunspot cycle: melatonin rise during the ascending phase of the cycle is accompanied by an increase of the sympathetic tone.

    Science.gov (United States)

    Bartsch, Christian; Bartsch, Hella; Seebald, Eckhard; Küpper, Heinz; Mecke, Dieter

    2014-05-01

    In two groups of female CD-rats nocturnal urine (19-23 h, 23-3 h, 3-7 h) was collected at monthly intervals over 658 days (I: 1997-1999) and 494 days (II: 1999-2000) coinciding with the ascending limb (1996-2000) of the 23rd sunspot cycle (1996-2008). The excretion of 6-sulfatoxymelatonin (aMT6s: I, II) was determined as well as the ratio of noradrenaline/adrenaline (NA/A: I) reflecting the activity of the sympathetic nervous system. AMT6s was higher in II than I (19-7 h: +24%; P sunspot cycle accompanied by growing geomagnetic disturbances (Ap) which elevate the sympathetic tone and thus affect the pineal gland, initially stimulating the activity of arylalkylamine N-acetyltransferase and subsequently fostering the expression of N-acetylserotonin O-methyltransferase (rate-limiting enzyme for melatonin biosynthesis) if Ap increases further. The potential (patho) physiological significance of these findings is discussed and the need for a systematic continuation of such studies is emphasized.

  20. Central command does not suppress baroreflex control of cardiac sympathetic nerve activity at the onset of spontaneous motor activity in the decerebrate cat.

    Science.gov (United States)

    Matsukawa, Kanji; Ishii, Kei; Asahara, Ryota; Idesako, Mitsuhiro

    2016-10-01

    Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in animals. We have examined whether baroreflex control of cardiac sympathetic nerve activity (CSNA) and/or cardiovagal baroreflex sensitivity are altered at the onset of spontaneously occurring motor behavior, which was monitored with tibial nerve activity in paralyzed, decerebrate cats. CSNA exhibited a peak increase (126 ± 17%) immediately after exercise onset, followed by increases in HR and mean arterial pressure (MAP). With development of the pressor response, CSNA and HR decreased near baseline, although spontaneous motor activity was not terminated. Atropine methyl nitrate (0.1-0.2 mg/kg iv) with little central influence delayed the initial increase in HR but did not alter the response magnitudes of HR and CSNA, while atropine augmented the pressor response. The baroreflex-induced decreases in CSNA and HR elicited by brief occlusion of the abdominal aorta were challenged at the onset of spontaneous motor activity. Spontaneous motor activity blunted the baroreflex reduction in HR by aortic occlusion but did not alter the baroreflex inhibition of CSNA. Similarly, atropine abolished the baroreflex reduction in HR but did not influence the baroreflex inhibition of CSNA. Thus it is likely that central command increases CSNA and decreases cardiac vagal outflow at the onset of spontaneous motor activity while preserving baroreflex control of CSNA. Accordingly, central command must attenuate cardiovagal baroreflex sensitivity against an excess rise in MAP as estimated from the effect of muscarinic blockade. Copyright © 2016 the American Physiological Society.

  1. 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 pressure

  2. The effect of residential exercise training on baroreflex control of heart rate and sympathetic nerve activity in patients with acute myocardial infarction.

    Science.gov (United States)

    Mimura, Jun; Yuasa, Fumio; Yuyama, Reisuke; Kawamura, Akihiro; Iwasaki, Masayoshi; Sugiura, Tetsuro; Iwasaka, Toshiji

    2005-04-01

    Exercise training has been shown to favorably affect the prognosis after acute myocardial infarction (AMI), but the mechanisms of such favorable effects remain speculative. The aim of this study was to determine whether exercise training improves baroreflex control of heart rate and muscle sympathetic nerve activity (MSNA) in patients with AMI. Prospective randomized clinical study. Thirty patients with an uncomplicated AMI were randomized into trained or untrained groups. Arterial BP, heart rate, and MSNA were measured at rest, and during baroreceptor stimulation (phenylephrine infusion) and baroreceptor deactivation (nitroprusside infusion). These measurements were performed at baseline and after 4 weeks of exercise training. Peak oxygen uptake increased significantly (12.3 +/- 10.7% [mean +/- SD]) with exercise training. Resting MSNA reduced from 34 +/- 12 to 27 +/- 8 bursts/min in the trained group but not in the untrained group. Arterial baroreflex sensitivity (BRS) [from 8.9 +/- 3.0 to 10.3 +/- 3.0 ms/mm Hg, p trained group, but not in the untrained group. Despite baroreceptor deactivation improving MSNA response in both groups, there was no significant difference between the two groups. Exercise training increased arterial BRS and decreased sympathetic nerve traffic after AMI, which indicate that the sympathoinhibitory effect of exercise training may, at least in part, contribute to the beneficial effect of exercise training in patients with AMI.

  3. Sympathetic baroreflex gain in normotensive pregnant women.

    Science.gov (United States)

    Usselman, Charlotte W; Skow, Rachel J; Matenchuk, Brittany A; Chari, Radha S; Julian, Colleen G; Stickland, Michael K; Davenport, Margie H; Steinback, Craig D

    2015-09-01

    Muscle sympathetic nerve activity is increased during normotensive pregnancy while mean arterial pressure is maintained or reduced, suggesting baroreflex resetting. We hypothesized spontaneous sympathetic baroreflex gain would be reduced in normotensive pregnant women relative to nonpregnant matched controls. Integrated muscle sympathetic burst incidence and total sympathetic activity (microneurography), blood pressure (Finometer), and R-R interval (ECG) were assessed at rest in 11 pregnant women (33 ± 1 wk gestation, 31 ± 1 yr, prepregnancy BMI: 23.5 ± 0.9 kg/m(2)) and 11 nonpregnant controls (29 ± 1 yr; BMI: 25.2 ± 1.7 kg/m(2)). Pregnant women had elevated baseline sympathetic burst incidence (43 ± 2 vs. 33 ± 2 bursts/100 heart beats, P = 0.01) and total sympathetic activity (1,811 ± 148 vs. 1,140 ± 55 au, P baroreflex set point with pregnancy. Baroreflex gain, calculated as the linear relationship between sympathetic burst incidence and DBP, was reduced in pregnant women relative to controls (-3.7 ± 0.5 vs. -5.4 ± 0.5 bursts·100 heart beats(-1)·mmHg(-1), P = 0.03), as was baroreflex gain calculated with total sympathetic activity (-294 ± 24 vs. -210 ± 24 au·100 heart beats(-1)·mmHg(-1); P = 0.03). Cardiovagal baroreflex gain (sequence method) was not different between nonpregnant controls and pregnant women (49 ± 8 vs. 36 ± 8 ms/mmHg; P = 0.2). However, sympathetic (burst incidence) and cardiovagal gains were negatively correlated in pregnant women (R = -0.7; P = 0.02). Together, these data indicate that the influence of the sympathetic nervous system over arterial blood pressure is reduced in normotensive pregnancy, in terms of both long-term and beat-to-beat regulation of arterial pressure, likely through a baroreceptor-dependent mechanism. Copyright © 2015 the American Physiological Society.

  4. 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....

  5. Inspiratory muscle training reduces sympathetic nervous activity and improves inspiratory muscle weakness and quality of life in patients with chronic heart failure: a clinical trial.

    Science.gov (United States)

    Mello, Priscila R; Guerra, Grazi M; Borile, Suellen; Rondon, Maria U; Alves, Maria J; Negrão, Carlos E; Dal Lago, Pedro; Mostarda, Cristiano; Irigoyen, Maria C; Consolim-Colombo, Fernanda M

    2012-01-01

    To evaluate the effect of inspiratory muscle training (IMT) on cardiac autonomic modulation and on peripheral nerve sympathetic activity in patients with chronic heart failure (CHF). Functional capacity, low-frequency (LF) and high-frequency (HF) components of heart rate variability, muscle sympathetic nerve activity inferred by microneurography, and quality of life were determined in 27 patients with CHF who had been sequentially allocated to 1 of 2 groups: (1) control group (with no intervention) and (2) IMT group. Inspiratory muscle training consisted of respiratory exercises, with inspiratory threshold loading of seven 30-minute sessions per week for a period of 12 weeks, with a monthly increase of 30% in maximal inspiratory pressure (PI(max)) at rest. Multivariate analysis was applied to detect differences between baseline and followup period. Inspiratory muscle training significantly increased PI(max) (59.2 ± 4.9 vs 87.5 ± 6.5 cmH(2)O, P = .001) and peak oxygen uptake (14.4 ± 0.7 vs 18.9 ± 0.8 mL·kg(-1)·min(-1), P = .002); decreased the peak ventilation (VE)/carbon dioxide production (VCO(2)) ratio (35.8 ± 0.8 vs 32.5 ± 0.4, P = .001) and the VE/VCO(2) slope (37.3 ± 1.1 vs 31.3 ± 1.1, P = .004); increased the HF component (49.3 ± 4.1 vs 58.4 ± 4.2 normalized units, P = .004) and decreased the LF component (50.7 ± 4.1 vs 41.6 ± 4.2 normalized units, P = .001) of heart rate variability; decreased muscle sympathetic nerve activity (37.1 ± 3 vs 29.5 ± 2.3 bursts per minute, P = .001); and improved quality of life. No significant changes were observed in the control group. Home-based IMT represents an important strategy to improve cardiac and peripheral autonomic controls, functional capacity, and quality of life in patients with CHF.

  6. Control plasma renin activity and changes in sympathetic tone as determinants of minoxidil-induced increase in plasma renin activity.

    Science.gov (United States)

    O'Malley, K; Velasco, M; Wells, J; McNay, J L

    1975-01-01

    A study was made of the possible mechanism(s) underlying minoxidil-induced increase in plasma renin activity (PRA). 10 patients with essential hypertension were treated with minoxidil and subsequently with a combination of minoxidil plus propranolol. Minoxidil lowered mean arterial pressure 31.6 plus or minus 3.3 mm Hg, mean plus or minus SEM. There was an associated increase in both PRA, 6.26 plus or minus 2.43 NG/ML/H, and heart rate, 21.4 plus or minus 2.7 beats/min. The changes in PRA and heart rate were positively correlated, r, 0.79. Addition of propranolol reduced mean arterial pressure by a further 10.1 plus or minus 1.5 mm Hg and returned heart rate to control levels. Propranolol reduced PRA significantly but not to control levels. Control PRA positively correlated with PRA on minoxidil, r, 0.97, and with PRA on minoxidil plus propranolol, r, 0.98. We conclude that control PRA is a major determinant of change in PRA with minoxidil. Minoxidil increased PRA by at least two mechanisms: (a) an adrenergic mechanism closely related to change in heart rate and blocked by propranolol, and (b) a mechanism(s) not sensitive to propranolol and possibly related to decrease in renal perfusion pressure. PMID:1127099

  7. Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal.

    Science.gov (United States)

    McConnell, Patrick A; Froeliger, Brett; Garland, Eric L; Ives, Jeffrey C; Sforzo, Gary A

    2014-01-01

    Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation), few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics [heart rate variability (HRV)] during post-exercise relaxation. Subjects (n = 21; 18-29 years old) participated in a double-blind, placebo-controlled study during which binaural beats and placebo were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design). At the onset of each visit, subjects exercised for 20-min; post-exercise, subjects listened to either binaural beats ('wide-band' theta-frequency binaural beats) or placebo (carrier tones) for 20-min while relaxing alone in a quiet, low-light environment. Dependent variables consisted of high-frequency (HF, reflecting parasympathetic activity), low-frequency (LF, reflecting sympathetic and parasympathetic activity), and LF/HF normalized powers, as well as self-reported relaxation. As compared to the placebo visit, the binaural-beat visit resulted in greater self-reported relaxation, increased parasympathetic activation and increased sympathetic withdrawal. By the end of the 20-min relaxation period there were no observable differences in HRV between binaural-beat and placebo visits, although binaural-beat associated HRV significantly predicted subsequent reported relaxation. Findings suggest that listening to binaural beats may exert an acute influence on both LF and HF components of HRV and may increase subjective feelings of relaxation.

  8. Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal

    Directory of Open Access Journals (Sweden)

    Patrick eMcConnell

    2014-11-01

    Full Text Available Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation, few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics (heart-rate variability (HRV during post-exercise relaxation. Subjects (n = 21; 18-29 years old participated in a double-blind, placebo-controlled study during which binaural beats and placebo were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design. At the onset of each visit, subjects exercised for 20-min; post-exercise, subjects listened to either binaural beats (‘wide-band’ theta-frequency binaural beats or placebo (carrier tone for 20-min while relaxing alone in a quiet, low-light environment. Dependent variables consisted of high frequency (HF, reflecting parasympathetic activity, low frequency (LF, reflecting sympathetic and parasympathetic activity and LF/HF normalized powers, as well as self-reported relaxation. As compared to the placebo visit, the binaural beat visit resulted in greater self-reported relaxation, as well as increased parasympathetic activation and sympathetic withdrawal. By the end of the 20-min relaxation period there were no observable differences in HRV between binaural beat and placebo visits, although binaural-beat associated HRV significantly predicted subsequent reported relaxation. Findings suggest that listening to binaural beats may exert an acute influence on both LF and HF components of HRV and may increase subjective feelings of relaxation.

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

    Science.gov (United States)

    Abdulla, M H; Johns, E J

    2014-04-01

    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). Anaesthetized (chloralose/urethane) rats were prepared to allow generation of baroreflex gain curves for RSNA or HR following intracerebroventricular (I.C.V.) CGP42112 (AT2 receptor agonist), PD123319 (AT2 receptor antagonist) or losartan (AT1 receptor antagonist), and then in combination with L-NAME (NO synthase inhibitor). I.C.V. PD123319, CGP42112, and Losartan did not change baseline mean arterial pressure, HR or RSNA. Baroreflex sensitivities for RSNA and HR were increased following AT2 receptor activation with CGP42112 by 112 and 157%, respectively, but were reduced following PD123319 by 20% (all P baroreflex sensitivity for both RSNA and HR, by 62 and 158%, respectively, but when co-infused with either CGP42112 or PD123319, the baroreflex sensitivity fell to values comparable to those obtained during I.C.V. saline infusion. The baroreflex sensitivities for RSNA and HR were increased by losartan by 92% and 192%, respectively, but in the presence of L-NAME were no different from those obtained during I.C.V. saline infusion. There is an important facilitatory role for AT2 receptors in the high-pressure baroreflex regulation of RSNA and HR which is dependent on a functional NO/NOS system. Conversely, AT1 receptors have an inhibitory effect on the baroreflex, an action that relies on a tonic inhibition of NO. © 2013 The Authors. Acta Physiologica published by John Wiley & Sons Ltd on behalf of Scandinavian Physiological Society.

  10. Effect of 4G-alpha-glucopyranosyl hesperidin on brown fat adipose tissue- and cutaneous-sympathetic nerve activity and peripheral body temperature.

    Science.gov (United States)

    Shen, Jiao; Nakamura, Hiroyasu; Fujisaki, Yoshiyuki; Tanida, Mamoru; Horii, Yuko; Fuyuki, Risa; Takumi, Hiroko; Shiraishi, Koso; Kometani, Takashi; Nagai, Katsuya

    2009-09-11

    Changes in the activity of the autonomic nervous system are good indicators of alterations in physiological phenomena such as the body temperature, blood glucose, blood pressure. Hesperidin, a flavanone known as vitamin P, has been shown to reduce the levels of serum lipids, cholesterol, and blood pressure. However, hesperidin is not water-soluble and is not well absorbed from the intestine. G-hesperidin (4G-alpha-glucopyranosyl hesperidin) is more water-soluble and more rapidly absorbed than hesperidin. In order to clarify the functions of G-hesperidin, we examined the effects of oral administration of G-hesperidin on interscapular brown adipose tissue-sympathetic nerve activity (BAT-SNA) and cutaneous sympathetic nerve activity (CASNA) in rats weighing about 300 g. In this study, we found that oral administration of 60 mg of G-hesperidin increased the BAT-SNA but decreased the CASNA in urethane-anesthetized rats. Since an elevation in BAT-SNA increases heat production (i.e. body temperature (BT)) and a decrease in CASNA increases cutaneous perfusion, we examined whether oral administration of G-hesperidin had an effect on the peripheral BT in rats. Consequently, we observed that the subcutaneous BT at the caudal end of the back after oral administration of 60 mg of G-hesperidin was significantly higher than the subcutaneous BT after oral administration of water in conscious rats. These findings suggest that G-hesperidin enhances the BAT-SNA and suppresses the CASNA resulting in an increase in the peripheral BT, probably by an increase in the thermogenesis in the BAT and an elevation in the cutaneous blood flow.

  11. Human in vivo study of the renin-angiotensin-aldosterone system and the sympathetic activity after 8 weeks daily intake of fermented milk

    DEFF Research Database (Denmark)

    Usinger, Lotte; Ibsen, Hans; Linneberg, Allan

    2010-01-01

    OBJECTIVE: Milk fermented by lactic acid bacteria is suggested to have antihypertensive effect in humans. In vitro and animal studies have established an angiotensin-converting enzyme (ACE) inhibitor effect of peptides in fermented milk. However, other modes of action must be considered, because...... until today no human studies have confirmed an ACE inhibition in relation to the intake of fermented milk. MATERIALS AND METHODS: We undertook a double-blinded randomized placebo-controlled study including 94 borderline-hypertensive persons to study the effect on human physiology of Lactobacillus...... helveticus fermented milk. The subjects were randomized into three groups: Cardi04-300 ml, Cardi04-150 ml or placebo. All components of the renin-angiotensin-aldosterone system were measured several times. Sympathetic activity was estimated by plasma noradrenaline and cardiovascular response to head-up tilt...

  12. Human in vivo study of the renin-angiotensin-aldosterone system and the sympathetic activity after 8 weeks daily intake of fermented milk.

    Science.gov (United States)

    Usinger, Lotte; Ibsen, Hans; Linneberg, Allan; Azizi, Michel; Flambard, Bénédicte; Jensen, Lars T

    2010-03-01

    Milk fermented by lactic acid bacteria is suggested to have antihypertensive effect in humans. In vitro and animal studies have established an angiotensin-converting enzyme (ACE) inhibitor effect of peptides in fermented milk. However, other modes of action must be considered, because until today no human studies have confirmed an ACE inhibition in relation to the intake of fermented milk. We undertook a double-blinded randomized placebo-controlled study including 94 borderline-hypertensive persons to study the effect on human physiology of Lactobacillus helveticus fermented milk. The subjects were randomized into three groups: Cardi04-300 ml, Cardi04-150 ml or placebo. All components of the renin-angiotensin-aldosterone system were measured several times. Sympathetic activity was estimated by plasma noradrenaline and cardiovascular response to head-up tilt at baseline and after 8 weeks of intervention. No ACE inhibition of the fermented milk was demonstrated, as none of the components of the renin-angiotensin-aldosteron system changed. Plasma noradrenaline response to tilt test after intervention stayed unchanged between groups (P = 0.38), but declined in the group Cardi04-300 from 2.01 +/- 0.93 nmol l(-1) at baseline to 1.49 +/- 0.74 nmol l(-1) after 8 weeks (P = 0.002). There was no change in 24-h ambulatory blood pressure or heart rate between groups. Despite a known ACE inhibitory effect in vitro and in animals, milk fermented with Lb. helveticus did not inhibit ACE in humans. Our results suggest that the intake of fermented milk decreases sympathetic activity, although not to an extent mediating reductions of blood pressure and heart rate in borderline-hypertensive subjects.

  13. Heat stress enhances arterial baroreflex control of muscle sympathetic nerve activity via increased sensitivity of burst gating, not burst area, in humans.

    Science.gov (United States)

    Keller, D M; Cui, J; Davis, S L; Low, D A; Crandall, C G

    2006-06-01

    The relationship between muscle sympathetic nerve activity (MSNA) and diastolic blood pressure has been used to describe two sites for arterial baroreflex control of MSNA. By determining both the likelihood of occurrence for sympathetic bursts and the area of each burst for a given diastolic blood pressure, both a 'gating' and an 'area' control site has been described in normothermic humans. Assessing the effect of heat stress on these mechanisms will improve the understanding of baroreflex control of arterial blood pressure under this thermal condition. Therefore, the purpose of this study was to test the hypothesis that heat stress enhances arterial baroreflex control of burst gating and area. In 10 normotensive subjects (age, 32+/-2 years; mean+/-s.e.m.), MSNA (peroneal) was assessed using standard microneurographic techniques. Five minute periods of data were examined during normothermic and whole-body heating conditions. The burst incidence (i.e. number of sympathetic bursts per 100 cardiac cycles) and the area of each burst were determined for each cardiac cycle and were placed into 3 mmHg intervals of diastolic blood pressure. During normotheric conditions, there was a moderate, negative relationship between burst incidence and diastolic blood pressure (slope=-2.49+/-0.38; r(2)=0.73+/-0.06; mean+/-s.e.m.), while area per burst relative to diastolic blood pressure exhibited a less strong relationship (slope=-1.13+/-0.46; r(2)=0.45+/-0.09). During whole-body heating there was an increase in the slope of the relationship between burst incidence and diastolic blood pressure (slope=-4.69+/-0.44; r(2)=0.84+/-0.03) compared to normothermia (Pburst and diastolic blood pressure was unchanged (slope=-0.92+/-0.29; r(2)=0.41+/-0.08) (P=0.50). The primary finding of this investigation is that, at rest, whole-body heating enhanced arterial baroreflex control of MSNA through increased sensitivity of a 'gating' mechanism, as indicated by an increase in the slope of the

  14. Physiological changes in human cardiac sympathetic innervation and activity assessed by 123I-metaiodobenzylguanidine (MIBG) imaging

    International Nuclear Information System (INIS)

    Sakata, Kazuyuki; Iida, Kei; Mochizuki, Nao; Ito, Michitoshi; Nakaya, Yoshihiro

    2009-01-01

    Physiologic changes in the human sympathetic nervous system (SNS) may be associated with cardiovascular diseases, so the present study assessed the age and gender differences in global cardiac SNS in normal subjects. The 163 subjects (74 men, 89 women; age range 40-89 years) whose coronary arteriogram was normal, and who had no other cardiac or neurohormonal diseases, and no medication affecting the autonomic nervous system were included. All study subjects underwent metaiodobenzylguanidine imaging. Both initial and delayed heart-to-mediastinum (H/M) ratios had a significant gender difference and showed a progressive decrease with aging. In addition, the initial H/M ratio had a significant positive correlation with the delayed H/M ratio (r=0.89, P<0.0001). Females (50-59 years) demonstrated significantly higher delayed H/M ratio than males of the same age. After the age of 60, the delayed H/M ratio in females progressively decreased with aging, similar to males. As for the washout rate, both genders had a significantly progressive increase with aging. In addition, there was a significant decrease in the delayed H/M ratio in 10 females with surgical menopause compared with 15 age-matched females without surgical menopause. Cardiac SNS appears to be regulated by various physiological factors. (author)

  15. Polyphenols, Antioxidants and the Sympathetic Nervous System.

    Science.gov (United States)

    Bruno, Rosa Maria; Ghiadoni, Lorenzo

    2017-11-14

    A high dietary intake of polyphenols has been associated with a reduced cardiovascular mortality, due to their antioxidant properties. However, growing evidence suggests that counteracting oxidative stress in cardiovascular disease might also reduce sympathetic nervous system overactivity. This article reviews the most commonly used techniques to measure sympathetic activity in humans; the role of sympathetic activation in the pathophysiology of cardiovascular diseases; current evidence demonstrating that oxidative stress is involved in the regulation of sympathetic activity and how antioxidants and polyphenols might counteract sympathetic overactivity, particularly focusing on preliminary data from human studies. The main mechanisms by which polyphenols are cardioprotective are related to the improvement of vascular function and their anti-atherogenic effect. Furthermore, a blood pressure-lowering effect was consistently demonstrated in randomized controlled trials in humans, when the effect of flavonoid-rich foods, such as tea and chocolate, was tested. More recent studies suggest that inhibition of sympathetic overactivity might be one of the mechanisms by which these substances exert their cardioprotective effects. Indeed, an increased adrenergic traffic to the vasculature is a major mechanism of disease in a number of cardiovascular and extra-cardiac diseases, including hypertension, obesity and metabolic syndrome and heart failure. A considerable body of evidence, mostly from experimental studies, support the hypothesis that reactive oxygen species might exert sympatho-excitatory effects both at the central and at the peripheral level. Accordingly, supplementation with antioxidants might reduce adrenergic overdrive to the vasculature and blunt cardiovascular reactivity to stress. While supplementation with "classical" antioxidants such as ROS-scavengers has many limitations, increasing the intake of polyphenol-rich foods seems to be a promising novel

  16. Sympathetic chain Schwannoma

    International Nuclear Information System (INIS)

    Al-Mashat, Faisal M.

    2009-01-01

    Schwannomas are rare, benign, slowly growing tumors arising from Schwann cells that line nerve sheaths. Schwannomas arising from the cervical sympathetic chain are extremely rare. Here, we report a case of a 70-year-old man who presented with only an asymptomatic neck mass. Physical examination revealed a left sided Horner syndrome and a neck mass with transmitted pulsation and anterior displacement of the carotid artery. Computed tomography (CT) showed a well-defined non-enhancing mass with vascular displacement. The nerve of origin of this encapsulated tumor was the sympathetic chain. The tumor was excised completely intact. The pathologic diagnosis was Schwannoma (Antoni type A and Antoni type B). The patient has been well and free of tumor recurrence for 14 months with persistence of asymptomatic left sided Horner syndrome. The clinical, radiological and pathological evaluations, therapy and postoperative complications of this tumor are discussed. (author)

  17. Salivary alpha amylase not chromogranin A reflects sympathetic activity: exercise responses in elite male wheelchair athletes with or without cervical spinal cord injury.

    Science.gov (United States)

    Leicht, Christof A; Paulson, Thomas A W; Goosey-Tolfrey, Victoria L; Bishop, Nicolette C

    2017-12-01

    Salivary alpha amylase (sAA) and chromogranin A (sCgA) have both been suggested as non-invasive markers for sympathetic nervous system (SNS) activity. A complete cervical spinal cord injury leading to tetraplegia is accompanied with sympathetic dysfunction; the aim of this study was to establish the exercise response of these markers in this in vivo model. Twenty-six elite male wheelchair athletes (C6-C7 tetraplegia: N = 8, T6-L1 paraplegia: N = 10 and non-spinal cord injured controls: N = 8) performed treadmill exercise to exhaustion. Saliva and blood samples were taken pre, post and 30 min post exercise and analysed for sAA, sCgA and plasma adrenaline concentration, respectively. In all three subgroups, sAA and sCgA were elevated post exercise (P < 0.05). Whilst sCgA was not different between subgroups, a group × time interaction for sAA explained the reduced post-exercise sAA activity in tetraplegia (162 ± 127 vs 313 ± 99 (paraplegia) and 328 ± 131 U mL -1 (controls), P = 0.005). The post-exercise increase in adrenaline was not apparent in tetraplegia (P = 0.74). A significant correlation was found between adrenaline and sAA (r = 0.60, P = 0.01), but not between adrenaline and sCgA (r = 0.06, P = 0.79). The blunted post-exercise rise in sAA and adrenaline in tetraplegia implies that both reflect SNS activity to some degree. It is questionable whether sCgA should be used as a marker for SNS activity, both due to the exercise response which is not different between the subgroups and its non-significant relationship with adrenaline.

  18. Adaptive servo-ventilation therapy improves cardiac sympathetic nerve activity, cardiac function, exercise capacity, and symptom in patients with chronic heart failure and Cheyne-Stokes respiration.

    Science.gov (United States)

    Toyama, Takuji; Hoshizaki, Hiroshi; Kasama, Shu; Miyaishi, Yusuke; Kan, Hakuken; Yamashita, Eiji; Kawaguti, Ren; Adachi, Hitoshi; Ohsima, Shigeru

    2017-12-01

    Adaptive servo-ventilation (ASV) therapy has been reported to be effective for improving central sleep apnea (CSA) and chronic heart failure (CHF). The purpose of this study was to clarify whether ASV is effective for CSA, cardiac sympathetic nerve activity (CSNA), cardiac symptoms/function, and exercise capacity in CHF patients with CSA and Cheyne-Stokes respiration (CSR-CSA). In this study, 31 CHF patients with CSR-CSA and a left ventricular ejection fraction (LVEF) ≤ 40% were randomized into an ASV group and a conservative therapy (non-ASV) group for 6 month. Nuclear imagings with 123 I-Metaiodobenzylguanidine (MIBG) and 99m Tc-Sestamibi were performed. Exercise capacity using a specific activity scale (SAS) and the New York Heart Association (NYHA) class were evaluated. CSNA was evaluated by 123 I-MIBG imaging, with the delayed heart/mediastinum activity ratio (H/M), delayed total defect score (TDS), and washout rate (WR). The ASV group had significantly better (P improvement of CSR-CSA, CSNA, cardiac symptoms/function, and exercise capacity in CHF patients with CSR-CSA.

  19. Effectiveness of nocturnal home oxygen therapy to improve exercise capacity, cardiac function and cardiac sympathetic nerve activity in patients with chronic heart failure and central sleep apnea.

    Science.gov (United States)

    Toyama, Takuji; Seki, Ryotaro; Kasama, Shu; Isobe, Naoki; Sakurai, Shigeki; Adachi, Hitoshi; Hoshizaki, Hiroshi; Oshima, Shigeru; Taniguchi, Koichi

    2009-02-01

    Central sleep apnea, often found in patients with chronic heart failure (CHF), has a high risk of poor prognosis. This study involved 20 patients with CHF (left ventricular ejection fraction (LVEF) 5 times/h who were divided into 2 groups: 10 patients treated with nocturnal home oxygen therapy (HOT) and 10 patients without HOT (non-HOT). All patients had dilated cardiomyopathy and underwent overnight polysomnography, cardiopulmonary exercise testing, and nuclear cardiac examinations to evaluate AHI, exercise capacity according to the specific activity scale and oxygen uptake at anaerobic threshold and peak exercise (peak VO(2)). Cardiac function according to (99m)Tc-MIBI QGS, and the total defect score (TDS), H/M ratio and the washout rate (WR) on (123)I-metaiodobenzylguanidine (MIBG) imaging were calculated for all patients. As compared with the non-HOT group, the HOT group demonstrated a greater reduction in AHI (26.1+/-9.1 to 5.1+/-3.4), (123)I-MIBG TDS (31+/-8 to 25+/-9), and (123)I-MIBG WR (48+/-8% to 41+/-5%) and a greater increase in the specific activity scale (4.0+/-0.9 to 5.8+/-1.2 Mets), peak VO(2) (16.0+/-3.8 to 18.3+/-4.7 ml . min(-1) . kg(-1)), and LVEF (27+/-9% to 37+/-10%). HOT improves exercise capacity, cardiac function, and cardiac sympathetic nerve activity in patients with CHF and central sleep apnea.

  20. Chronic baroreflex activation effects on sympathetic nerve traffic, baroreflex function, and cardiac haemodynamics in heart failure: a proof-of-concept study.

    Science.gov (United States)

    Gronda, Edoardo; Seravalle, Gino; Brambilla, Gianmaria; Costantino, Giuseppe; Casini, Andrea; Alsheraei, Ali; Lovett, Eric G; Mancia, Giuseppe; Grassi, Guido

    2014-09-01

    Heart failure (HF) pathophysiology is believed to be mediated by autonomic dysfunction, including chronic sympathoexcitation and diminished baroreflex sensitivity, which correlate with mortality risk. Baroreflex activation therapy (BAT) is a device-based treatment providing chronic baroreflex activation through electrical stimulation of the carotid sinus. BAT chronically reduces sympathetic activity in resistant hypertension. The purpose of this investigation is to determine BAT effects in clinical HF. In a single-centre, open-label evaluation, patients with NYHA class III HF, EF baroreflex sensitivity, EF, NYHA class, quality of life and 6 min hall walk (6 MHW) distance (P ≤ 0.05 each). On an observational basis, hospitalization and emergency department visits for worsening HF were markedly reduced. One complication, perioperative anaemia requiring transfusion, occurred during the study. BAT was safe and provided chronic improvement in MSNA and clinical variables. Based on present understanding of HF pathophysiology, these results suggest that BAT may improve outcome in HF by modulating autonomic balance. Prospective, randomized trials to test the hypothesis are warranted. © 2014 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.

  1. The Potential of the Bi-Directional Gaze: A Call for Neuroscientific Research on the Simultaneous Activation of the Sympathetic and Parasympathetic Nervous Systems through Tantric Practice

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Lidke

    2016-11-01

    Full Text Available This paper is a call for the development of a neuroscientific research protocol for the study of the impact of Tantric practice on the autonomic nervous system. Tantric texts like Abhinavagupta’s Tantrāloka map out a complex meditative ritual system in which inward-gazing, apophatic, sense-denying contemplative practices are combined with outward-gazing, kataphatic sense-activating ritual practices. Abhinavagupta announces a culminating “bi-directional” state (pratimīlana-samādhi as the highest natural state (sahaja-samādhi in which the practitioner becomes a perfected yogi (siddhayogi. This state of maximized cognitive capacities, in which one’s inward gaze and outward world-engagement are held in balance, appears to be one in which the anabolic metabolic processes of the parasympathetic nervous system and the catabolic metabolic processes of the sympathetic nervous systems are simultaneously activated and integrated. Akin to secularized mindfulness and compassion training protocols like Emory’s CBCT, I propose the development of secularized “Tantric protocols” for the development of secular and tradition-specific methods for further exploring the potential of the human neurological system.

  2. Reflex sympathetic dystrophy in hemiplegia.

    Science.gov (United States)

    Gokkaya, Nilufer Kutay Ordu; Aras, Meltem; Yesiltepe, Elcin; Koseoglu, Fusun

    2006-12-01

    There is a high incidence of reflex sympathetic dystrophy of the upper limbs in patients with hemiplegia, and its painful and functional consequences present a problem to specialists in physical medicine and rehabilitation. This study was designed to assess the role of several factors in the occurrence of reflex sympathetic dystrophy in patients with hemiplegia. Ninety-five consecutive stroke patients (63 male and 32 female, mean age 59+/-12 years) admitted to our hospital were evaluated. Of the study group, 29 patients (30.5%) were found to develop reflex sympathetic dystrophy. There were no significant differences between the hemiplegic patient groups with or without reflex sympathetic dystrophy regarding age, gender, etiology, side of involvement, disease duration and the presence of comorbidities. The recovery stages of hemiplegia, as shown by Brunnstrom functional classification, were significantly different between the two groups; patients in lower recovery stages tended to develop reflex sympathetic dystrophy more frequently (Preflex sympathetic dystrophy. Glenohumeral subluxation was present in 37 patients (38.9%) in our study group and the presence of this complication was related to the occurrence of reflex sympathetic dystrophy. The presence of glenohumeral subluxation was significantly higher in patients with reflex sympathetic dystrophy (21/29, 72.4%) when compared to the patients without reflex sympathetic dystrophy (16/66, 24.2%) (Preflex sympathetic dystrophy. These results suggest that lower recovery stages, reduced tonus and glenohumeral subluxation significantly contribute to the occurrence of reflex sympathetic dystrophy in the hemiplegic patient. We believe that preventive and treatment measures should consider these factors as they seem to have in common a higher risk of traumatizing the paralyzed upper limb and causing reflex sympathetic dystrophy.

  3. Anatomic Variation of Rami Communicantes in the Upper Thoracic Sympathetic Chain: A Human Cadaveric Study.

    Science.gov (United States)

    Street, Elliot; Ashrafi, Mohammed; Greaves, Nicholas; Gouldsborough, Ingrid; Baguneid, Mohamed

    2016-07-01

    Hyperhidrosis is secondary to over activation of the sympathetic nervous system and surgical sympathectomy is the treatment of choice when other modalities have failed. This study investigated anatomic variation in the upper thoracic sympathetic chain and associated rami communicantes among cadaveric specimens. It considers the implications of these findings on surgical techniques to treat hyperhidrosis. The upper 4 thoracic sympathetic ganglia, intercostal nerves, and connecting rami were dissected, measured and mapped in 40 sides of 20 adult human cadavers. Ganglia location was recorded. The incidence, orientation, and distance travelled by rami communicantes was compared across different ganglionic levels and between sides. The percentage of ganglia located below their associated intercostal space was 6.25% with stellate ganglions present in 70% of specimens and Kuntz fibers noted in 40%. There was a stepwise reduction in incidence of rami from superior to inferior placed ganglia. The number of rami identified across all levels was significantly greater on the right (P = 0.03). The horizontal distance between the sympathetic chain and union of the rami on the intercostal nerves was significantly greater on the right across all levels (P = 0.04). There was substantial variation in the rami communicantes across the upper 4 ganglia and between right and left sides. Consideration of this variation should be given when planning surgical sympathectomy for hyperhidrosis particularly to avoid symptom recurrence. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. A randomized controlled study on the effects of bisoprolol and atenolol on sympathetic nervous activity and central aortic pressure in patients with essential hypertension.

    Directory of Open Access Journals (Sweden)

    Wei-Jun Zhou

    Full Text Available β-blockers (BBs with different pharmacological properties may have heterogeneous effects on sympathetic nervous activity (SNA and central aortic pressure (CAP, which are independent cardiovascular factors for hypertension. Hence, we analyzed the effects of bisoprolol and atenolol on SNA and CAP in hypertensive patients.This was a prospective, randomized, controlled study in 109 never-treated hypertensive subjects randomized to bisoprolol (5 mg or atenolol (50 mg for 4-8 weeks. SNA, baroreflex sensitivity (BRS and heart rate (HR variability (HRV were measured using power spectral analysis using a Finometer. CAP and related parameters were determined using the SphygmoCor device (pulse wave analysis.Both drugs were similarly effective in reducing brachial BP. However, central systolic BP (-14±10 mm Hg vs -6±9 mm Hg; P0.05. BRS was stable when RHR was controlled (RHR≤65 bpm, and the two treatments had similar effects on the low frequency/high frequency (HF ratio and on HF.BBs seem to have different effects on arterial distensibility and compliance in hypertensive subjects. Compared with atenolol, bisoprolol may have a better effect on CAP.ClinicalTrials.gov NCT01762436.

  5. AMPUTATION AND REFLEX SYMPATHETIC DYSTROPHY

    NARCIS (Netherlands)

    GEERTZEN, JHB; EISMA, WH

    Reflex sympathetic dystrophy is a chronic pain syndrome characterized by chronic burning pain, restricted range of motion, oedema and vasolability. Patients are difficult to treat and the prognosis is very often poor. This report emphasizes that an amputation in case of a reflex sympathetic

  6. Effectiveness of nocturnal home oxygen therapy to improve exercise capacity, cardiac function and cardiac sympathetic nerve activity in patients with chronic heart failure and central sleep apnea

    International Nuclear Information System (INIS)

    Toyama, Takuji; Seki, Ryotaro; Isobe, Naoki; Sakurai, Shigeki; Adachi, Hitoshi; Hoshizaki, Hiroshi; Oshima, Shigeru; Taniguchi, Koichi; Kasama, Shu

    2009-01-01

    Central sleep apnea, often found in patients with chronic heart failure (CHF), has a high risk of poor prognosis. This study involved 20 patients with CHF (left ventricular ejection fraction (LVEF) 5 times/h who were divided into 2 groups: 10 patients treated with nocturnal home oxygen therapy (HOT) and 10 patients without HOT (non-HOT). All patients had dilated cardiomyopathy and underwent overnight polysomnography, cardiopulmonary exercise testing, and nuclear cardiac examinations to evaluate AHI, exercise capacity according to the specific activity scale and oxygen uptake at anaerobic threshold and peak exercise (peak VO 2 ). Cardiac function according to 99m Tc-methoxyisobutylisonitrile (MIBI) QGS, and the total defect score (TDS), H/M ratio and the washout rate (WR) on 123 I-metaiodobenzylguanidine (MIBG) imaging were calculated for all patients. As compared with the non-HOT group, the HOT group demonstrated a greater reduction in AHI (26.1±9.1 to 5.1±3.4), 123 I-MIBG TDS (31±8 to 25±9), and 123 I-MIBG WR (48±8% to 41±5%) and a greater increase in the specific activity scale (4.0±0.9 to 5.8±1.2 Mets), peak VO 2 (16.0±3.8 to 18.3±4.7 ml·min -1 ·kg -1 ), and LVEF (27±9% to 37±10%). HOT improves exercise capacity, cardiac function, and cardiac sympathetic nerve activity in patients with CHF and central sleep apnea. (author)

  7. 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

  8. Sympathetic modulation of muscle spindle afferent sensitivity to stretch in rabbit jaw closing muscles.

    Science.gov (United States)

    Roatta, S; Windhorst, U; Ljubisavljevic, M; Johansson, H; Passatore, M

    2002-04-01

    Previous reports showed that sympathetic stimulation affects the activity of muscle spindle afferents (MSAs). The aim of the present work is to study the characteristics of sympathetic modulation of MSA response to stretch: (i) on the dynamic and static components of the stretch response, and (ii) on group Ia and II MSAs to evaluate potentially different effects. In anaesthetised rabbits, the peripheral stump of the cervical sympathetic nerve (CSN) was stimulated at 10 impulses s(-1) for 45-90 s. The responses of single MSAs to trapezoidal displacement of the mandible were recorded from the mesencephalic trigeminal nucleus. The following characteristic parameters were determined from averaged trapezoidal responses: initial frequency (IF), peak frequency at the end of the ramp (PF), and static index (SI). From these, other parameters were derived: dynamic index (DI = PF - SI), dynamic difference (DD = PF - IF) and static difference (SD = SI - IF). The effects of CSN stimulation were also evaluated during changes in the state of intrafusal muscle fibre contraction induced by succinylcholine and curare. In a population of 124 MSAs, 106 units (85.4 %) were affected by sympathetic stimulation. In general, while changes in resting discharge varied among different units (Ia vs. II) and experimental conditions (curarised vs. non-curarised), ranging from enhancement to strong depression of firing, the amplitude of the response to muscle stretches consistently decreased. This was confirmed and detailed in a quantitative analysis performed on 49 muscle spindle afferents. In both the non-curarised (23 units) and curarised (26 units) condition, stimulation of the CSN reduced the response amplitude in terms of DD and SD, but hardly affected DI. The effects were equally present in both Ia and II units; they were shown to be independent from gamma drive and intrafusal muscle tone and not secondary to muscle hypoxia. Sympathetic action on the resting discharge (IF) was less

  9. Contribution of α-adrenoceptors to depolarization and contraction evoked by continuous asynchronous sympathetic nerve activity in rat tail artery

    Science.gov (United States)

    Brock, J A; McLachlan, E M; Rayner, S E

    1997-01-01

    The effects of continuous but asynchronous nerve activity induced by ciguatoxin (CTX-1) on the membrane potential and contraction of smooth muscle cells have been investigated in rat proximal tail arteries isolated in vitro. These effects have been compared with those produced by the continuous application of phenylephrine (PE).CTX-1 (0.4 nM) and PE (10 μM) produced a maintained depolarization of the arterial smooth muscle that was almost completely blocked by α-adrenoceptor blockade. In both cases, the depolarization was more sensitive to the selective α2-adrenoceptor antagonist, idazoxan (0.1 μM), than to the selective α1-adrenoceptor antagonist, prazosin (0.01 μM).In contrast, the maintained contraction of the tail artery induced by CTX-1 (0.2 nM) and PE (2 and 10 μM) was more sensitive to prazosin (0.01) μM, than to idazoxan (0.01 μM). In combination, these antagonists almost completely inhibited contraction to both agents.Application of the calcium channel antagonist, nifedipine (1 μM), had no effect on the depolarization induced by either CTX-1 or PE but maximally reduced the force of the maintained contraction to both agents by about 50%.We conclude that the constriction of the tail artery induced by CTX-1, which mimics the natural discharge of postganglionic perivascular axons, is due almost entirely to α-adrenoceptor activation. The results indicate that neuronally released noradrenaline activates more than one α-adrenoceptor subtype. The depolarization is dependent primarily on α2-adrenoceptor activation whereas the contraction is dependent primarily on α1-adrenoceptor activation. The links between α-adrenoceptor activation and the voltage-dependent and voltage-independent mechanisms that deliver Ca2+ to the contractile apparatus appear to be complex. PMID:9113373

  10. Sympathetic Response to Insulin is Mediated by Melanocortin 3/4 Receptors in the Hypothalamic Paraventricular Nucleus

    OpenAIRE

    Ward, Kathryn R.; Bardgett, James F.; Wolfgang, Lawrence; Stocker, Sean D.

    2011-01-01

    Hyperinsulinemia increases sympathetic nerve activity and contributes to cardiovascular dysfunction in obesity and diabetes. Neurons of the hypothalamic paraventricular nucleus regulate sympathetic nerve activity through mono- and poly-synaptic connections to preganglionic neurons in the spinal cord. The purpose of the present study was to determine whether hypothalamic paraventricular nucleus neurons mediate the sympathetic response to insulin. Hyperinsulinemic-euglycemic clamps were perform...

  11. Suppression of sympathetic detonation

    Science.gov (United States)

    Foster, J. C., Jr.; Gunger, M. E.; Craig, B. G.; Parsons, G. H.

    1984-08-01

    There are two basic approaches to suppression of sympathetic detonation. Minimizing the shock sensitivity of the explosive to long duration pressure will obviously reduce interround separation distances. However, given that the explosive sensitivity is fixed, then much can be gained through the use of simple barriers placed between the rounds. Researchers devised calculational methods for predicting shock transmission; experimental methods have been developed to characterize explosive shock sensitivity and observe the response of acceptors to barriers. It was shown that both EAK and tritonal can be initiated to detonation with relatively low pressure shocks of long durations. It was also shown that to be an effective barrier between the donor and acceptor, the material must attenuate shock and defect fragments. Future actions will concentrate on refining the design of barriers to minimize weight, volume, and cost.

  12. Altered differential control of sympathetic outflow following sedentary conditions: Role of subregional neuroplasticity in the RVLM

    Directory of Open Access Journals (Sweden)

    Madhan Subramanian

    2016-07-01

    Full Text Available Despite the classically held belief of an all-or-none activation of the sympathetic nervous system, differential responses in sympathetic nerve activity (SNA can occur acutely at varying magnitudes and in opposing directions. Sympathetic nerves also appear to contribute differentially to various disease states including hypertension and heart failure. Previously we have reported that sedentary conditions enhanced responses of splanchnic SNA (SSNA but not lumbar SNA (LSNA to activation of the rostral ventrolateral medulla (RVLM in rats. Bulbospinal RVLM neurons from sedentary rats also exhibit increased dendritic branching in rostral regions of the RVLM. We hypothesized that regionally specific structural neuroplasticity would manifest as enhanced SSNA but not LSNA following activation of the rostral RVLM. To test this hypothesis, groups of physically active (10-12 weeks on running wheels or sedentary, male Sprague-Dawley rats were instrumented to record mean arterial pressure, LSNA and SSNA under Inactin anesthesia and during microinjections of glutamate (30 nl, 10 mM into multiple sites within the RVLM. Sedentary conditions enhanced SSNA but not LSNA responses and SSNA responses were enhanced at more central and rostral sites. Results suggest that enhanced SSNA responses in rostral RVLM coincide with enhanced dendritic branching in rostral RVLM observed previously. Identifying structural and functional neuroplasticity in specific populations of RVLM neurons may help identify new treatments for cardiovascular diseases, known to be more prevalent in sedentary individuals.

  13. Altered Differential Control of Sympathetic Outflow Following Sedentary Conditions: Role of Subregional Neuroplasticity in the RVLM

    Science.gov (United States)

    Subramanian, Madhan; Mueller, Patrick J.

    2016-01-01

    Despite the classically held belief of an “all-or-none” activation of the sympathetic nervous system, differential responses in sympathetic nerve activity (SNA) can occur acutely at varying magnitudes and in opposing directions. Sympathetic nerves also appear to contribute differentially to various disease states including hypertension and heart failure. Previously we have reported that sedentary conditions enhanced responses of splanchnic SNA (SSNA) but not lumbar SNA (LSNA) to activation of the rostral ventrolateral medulla (RVLM) in rats. Bulbospinal RVLM neurons from sedentary rats also exhibit increased dendritic branching in rostral regions of the RVLM. We hypothesized that regionally specific structural neuroplasticity would manifest as enhanced SSNA but not LSNA following activation of the rostral RVLM. To test this hypothesis, groups of physically active (10–12 weeks on running wheels) or sedentary, male Sprague-Dawley rats were instrumented to record mean arterial pressure, LSNA and SSNA under Inactin anesthesia and during microinjections of glutamate (30 nl, 10 mM) into multiple sites within the RVLM. Sedentary conditions enhanced SSNA but not LSNA responses and SSNA responses were enhanced at more central and rostral sites. Results suggest that enhanced SSNA responses in rostral RVLM coincide with enhanced dendritic branching in rostral RVLM observed previously. Identifying structural and functional neuroplasticity in specific populations of RVLM neurons may help identify new treatments for cardiovascular diseases, known to be more prevalent in sedentary individuals. PMID:27486405

  14. Mineralocorticoid Receptors, Inflammation and Sympathetic Drive in Heart Failure

    Science.gov (United States)

    Felder, Robert B.

    2010-01-01

    Appreciation for the role of aldosterone and mineralocorticoid receptors in cardiovascular disease is accelerating rapidly. Recent experimental work has unveiled a strong relationship between brain mineralocorticoid receptors and sympathetic drive, an important determinant of outcome in heart failure and hypertension. Two putative mechanisms are explored in this manuscript. First, brain mineralocorticoid receptors may influence sympathetic discharge by regulating the release of pro-inflammatory cytokines into the circulation. Blood-borne pro-inflammatory cytokines act upon receptors in the microvasculature of the brain to induce cyclooxygenase-2 activity and the production of prostaglandin E2, which penetrates the blood-brain barrier to activate the sympathetic nervous system. Second, brain mineralocorticoid receptors may influence sympathetic drive by upregulating the activity of the brain renin-angiotensin system, resulting in NAD(P)H oxidase dependent superoxide production. A potential role for superoxide dependent mitogen-activated protein kinase signaling pathways in the regulation of sympathetic nerve activity is also considered. Other potential downstream signaling mechanisms contributing to mineralocorticoid receptor mediated sympathetic excitation are under investigation. PMID:19648480

  15. Morning blood pressure surge is associated with arterial stiffness and sympathetic baroreflex sensitivity in hypertensive seniors

    Science.gov (United States)

    Okada, Yoshiyuki; Galbreath, M. Melyn; Shibata, Shigeki; Jarvis, Sara S.; Bivens, Tiffany B.; Vongpatanasin, Wanpen; Levine, Benjamin D.

    2013-01-01

    Morning blood pressure (BP) surge is considered to be an independent risk factor for cardiovascular diseases. We tested the hypothesis that increased large-artery stiffness and impaired sympathetic baroreflex sensitivity (BRS) contribute to augmented morning surge in elderly hypertensive subjects. Morning surge was assessed as morning systolic BP averaged for 2 h just after waking up minus minimal sleeping systolic BP by using ambulatory BP monitoring (ABPM) in 40 untreated hypertensive [68 ± 1 (SE) yr] and 30 normotensive (68 ± 1 yr) subjects. Beat-by-beat finger BP and muscle sympathetic nerve activity (MSNA) were recorded in the supine position and at 60° upright tilt. We assessed arterial stiffness with carotid-to-femoral pulse wave velocity (cfPWV) and sympathetic BRS during spontaneous breathing. Awake and asleep ABPM-BPs and morning surge were higher in hypertensive than normotensive subjects (all P morning surge ≥35 mmHg (median value) had higher cfPWV (11.9 ± 0.5 vs. 9.9 ± 0.4 m/s, P = 0.002) and lower sympathetic BRS (supine: −2.71 ± 0.25 vs. −3.73 ± 0.29, P = 0.011; upright: −2.62 ± 0.22 vs. −3.51 ± 0.35 bursts·100 beats−1·mmHg−1, P = 0.052) than those with morning surge 0.05), while upright total peripheral resistance was higher in hypertensive subjects with greater morning surge than those with lesser morning surge (P = 0.050). Morning surge was correlated positively with cfPWV (r = 0.59, P morning BP surge is associated with arterial stiffness and sympathetic BRS, as well as vasoreactivity during orthostasis in hypertensive seniors. PMID:23832695

  16. Evaluation of cardiac sympathetic nerve activity and aldosterone suppression in patients with acute decompensated heart failure on treatment containing intravenous atrial natriuretic peptide

    International Nuclear Information System (INIS)

    Kasama, Shu; Toyama, Takuji; Kurabayashi, Masahiko; Iwasaki, Toshiya; Sumino, Hiroyuki; Kumakura, Hisao; Minami, Kazutomo; Ichikawa, Shuichi; Matsumoto, Naoya; Nakata, Tomoaki

    2014-01-01

    Aldosterone prevents the uptake of norepinephrine in the myocardium. Atrial natriuretic peptide (ANP), a circulating hormone of cardiac origin, inhibits aldosterone synthase gene expression in cultured cardiocytes. We evaluated the effects of intravenous ANP on cardiac sympathetic nerve activity (CSNA) and aldosterone suppression in patients with acute decompensated heart failure (ADHF). We studied 182 patients with moderate nonischemic ADHF requiring hospitalization and treated with standard therapy containing intravenous ANP and 10 age-matched normal control subjects. ANP was continuously infused for >96 h. In all subjects, delayed total defect score (TDS), heart to mediastinum ratio, and washout rate were determined by 123 I-metaiodobenzylguanidine (MIBG) scintigraphy. Left ventricular (LV) end-diastolic volume, end-systolic volume, and ejection fraction were determined by echocardiography. All patients with acute heart failure (AHF) were examined once within 3 days and then 4 weeks after admission, while the control subjects were examined only once (when their hemodynamics were normal). Moreover, for 62 AHF patients, plasma aldosterone concentrations were measured at admission and 1 h before stopping ANP infusion. 123 I-MIBG scintigraphic and echocardiographic parameters in normal subjects were more favorable than those in patients with AHF (all p < 0.001). After treatment, all these parameters improved significantly in AHF patients (all p < 0.001). We also found significant correlation between percent changes of TDS and aldosterone concentrations (r = 0.539, p < 0.001) in 62 AHF patients. The CSNA and LV performance were all improved in AHF patients. Furthermore, norepinephrine uptake of myocardium may be ameliorated by suppressing aldosterone production after standard treatment containing intravenous ANP. (orig.)

  17. A combination of P wave electrocardiography and plasma brain natriuretic peptide level for predicting the progression to persistent atrial fibrillation: comparisons of sympathetic activity and left atrial size.

    Science.gov (United States)

    Akutsu, Yasushi; Kaneko, Kyouichi; Kodama, Yusuke; Miyoshi, Fumito; Li, Hui-Ling; Watanabe, Norikazu; Asano, Taku; Tanno, Kaoru; Suyama, Jumpei; Namiki, Atsuo; Gokan, Takehiko; Kobayashi, Youichi

    2013-11-01

    Development of atrial fibrillation (AF) is complexly associated with electrical and structural remodeling and other factors every stage of AF development. We hypothesized that P wave electrocardiography with an elevated brain natriuretic peptide (BNP) level would be associated with the progression to persistence from paroxysmal AF. P wave electrocardiography such as a maximum P wave duration (MPWD) and dispersion by 12-leads ECG, heart/mediastinum (H/M) ratio by delayed iodine-123 metaiodobenzylguanidine scintigraphic imaging, left ventricular ejection fraction (LVEF), and left atrial dimension (LAD) by echocardiography, and plasma BNP level were measured to evaluate the electrical and structural properties and sympathetic activity in 71 patients (mean ± standard deviation, age: 67 ± 13 years, 63.4 % males) with idiopathic paroxysmal AF. Over a 12.9-year follow-up period, AF developed into persistent AF in 30 patients. A wider MPWD (>129 ms) (p = 0.001), wider P wave dispersion (>60 ms) (p = 0.001), LAD enlargement (>40 mm) (p = 0.001), higher BNP level (>72 pg/mL) (p = 0.002), lower H/M ratio (≤2.7) (p = 0.025), and lower LVEF (≤60 %) (p = 0.035) were associated with the progression to persistent AF, and the wide MPWD was an independently powerful predictor of the progression to persistent AF with a hazard ratio (HR) of 5.49 [95 % confidence interval (CI) 2.38-12.7, p < 0.0001] after adjusting for potential confounding variables, such as age and sex. The combination of wide MPWD and elevated BNP level was additive and incremental prognostic power with 13.3 [2.16-13, p < 0.0001]. The wide MPWD with elevated BNP level was associated with the progression to persistent AF.

  18. A shift in myocardial substrate, improved endothelial function, and diminished sympathetic activity may contribute to the anti-anginal impact of very-low-fat diets.

    Science.gov (United States)

    McCarty, M F

    2004-01-01

    A new category of anti-anginal drug - exemplified by ranolazine - is believed to work by partially inhibiting cardiac oxidation of fatty acids; oxidation of glucose requires less oxygen per mol of ATP generated, and thus is preferable to fat oxidation when oxygen availability is limiting in underperfused cardiac tissue. Unfortunately, there is no reason to believe that these drugs inhibit fat oxidation selectively in the heart; thus, chronic use of these drugs can be expected to increase body fat stores until the original rate of fat oxidation is restored by mass action - presumably negating the therapeutic benefit in angina, while exacerbating the manifold adverse effects of insulin resistance syndrome. The rational way to decrease cardiac metabolic reliance on fatty acids is to consume a very-low-fat quasi-vegan diet (i.e., 10% fat calories). Indeed, such diets are known to have a rapid and substantial therapeutic impact on anginal symptoms, while concurrently benefiting insulin sensitivity, markedly improving serum lipid profile, promoting leanness, and lessening coronary risk. A reduction in diurnal insulin secretion might also be achieved, which would be expected to decrease sympathetic activity. While reduced myocardial demand for oxygen doubtless contributes to the beneficial impact of such diets on angina, it is likely that improved cardiac perfusion consequent to improved endothelium-dependent vasodilation also plays a role in this regard. Supplemental carnitine, also beneficial in angina, appears to improve utilization of glucose in the ischemic myocardium by lowering elevated acetyl-coA levels and thereby disinhibiting pyruvate dehydrogenase. Certain other nutraceuticals may aid control of angina by improving endothelial function. In the longer term, these measures have the potential to slow or reverse the progression of stenotic lesions that underlie most cases of angina. These safe and relatively inexpensive nutritional strategies for coping with

  19. Evaluation of cardiac sympathetic nerve activity and aldosterone suppression in patients with acute decompensated heart failure on treatment containing intravenous atrial natriuretic peptide

    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; Kurabayashi, Masahiko [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Iwasaki, Toshiya; Sumino, Hiroyuki; Kumakura, Hisao; Minami, Kazutomo; Ichikawa, Shuichi [Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Matsumoto, Naoya [Nihon University School of Medicine, Department of Cardiology, Tokyo (Japan); Nakata, Tomoaki [Sapporo Medical University School of Medicine, Second (Cardiology) Department of Internal Medicine, Sapporo, Hokkaido (Japan)

    2014-09-15

    Aldosterone prevents the uptake of norepinephrine in the myocardium. Atrial natriuretic peptide (ANP), a circulating hormone of cardiac origin, inhibits aldosterone synthase gene expression in cultured cardiocytes. We evaluated the effects of intravenous ANP on cardiac sympathetic nerve activity (CSNA) and aldosterone suppression in patients with acute decompensated heart failure (ADHF). We studied 182 patients with moderate nonischemic ADHF requiring hospitalization and treated with standard therapy containing intravenous ANP and 10 age-matched normal control subjects. ANP was continuously infused for >96 h. In all subjects, delayed total defect score (TDS), heart to mediastinum ratio, and washout rate were determined by {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy. Left ventricular (LV) end-diastolic volume, end-systolic volume, and ejection fraction were determined by echocardiography. All patients with acute heart failure (AHF) were examined once within 3 days and then 4 weeks after admission, while the control subjects were examined only once (when their hemodynamics were normal). Moreover, for 62 AHF patients, plasma aldosterone concentrations were measured at admission and 1 h before stopping ANP infusion. {sup 123}I-MIBG scintigraphic and echocardiographic parameters in normal subjects were more favorable than those in patients with AHF (all p < 0.001). After treatment, all these parameters improved significantly in AHF patients (all p < 0.001). We also found significant correlation between percent changes of TDS and aldosterone concentrations (r = 0.539, p < 0.001) in 62 AHF patients. The CSNA and LV performance were all improved in AHF patients. Furthermore, norepinephrine uptake of myocardium may be ameliorated by suppressing aldosterone production after standard treatment containing intravenous ANP. (orig.)

  20. Reflex Sympathetic Dystrophy in Children

    Directory of Open Access Journals (Sweden)

    Adnan Ayvaz

    2013-10-01

    Full Text Available    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 and usually follows minor injury or trauma. In this paper, two girl patients with reflex sympathetic dystrophy are discussed along with the laboratory and clinic finding by accompaniment the literature as it is rarely seen in childhood.

  1. Hepatic intestinal uptake and release of catecholamines in alcoholic cirrhosis. Evidence of enhanced hepatic intestinal sympathetic nervous activity

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Ring-Larsen, H; Christensen, N J

    1987-01-01

    Hepatic intestinal and whole body plasma clearance and appearance of noradrenaline (NA) was quantified in patients with alcoholic cirrhosis (n = 12) and in controls (n = 6). As NA may be released as well as removed in the same vascular bed, infusion of tritium labelled NA (3H-NA) was carried out...... during hepatic vein catheterisation in order to determine both flux rates. In alcoholic cirrhosis plasma concentrations of endogenous NA and adrenaline (A) were significantly above control values (NA: median 2.4 v 1.7 nmol/l, p less than 0.02; A: 0.38 v 0.19 nmol/l, p less than 0.01). Whole body...... clearance of 3H-NA equal in the two groups (1.6 v 1.7 l/min, ns), while as the overall appearance rate of NA was significantly higher in alcoholic cirrhosis (4.2 v 2.6 nmol/min, p less than 0.02) indicating an enhanced sympathoadrenal activity in this group. The hepatic intestinal clearances of A, NA, and 3...

  2. Large-scale recording of astrocyte activity

    Science.gov (United States)

    Nimmerjahn, Axel; Bergles, Dwight E.

    2015-01-01

    Astrocytes are highly ramified glial cells found throughout the central nervous system (CNS). They express a variety of neurotransmitter receptors that can induce widespread chemical excitation, placing these cells in an optimal position to exert global effects on brain physiology. However, the activity patterns of only a small fraction of astrocytes have been examined and techniques to manipulate their behavior are limited. As a result, little is known about how astrocytes modulate CNS function on synaptic, microcircuit, or systems levels. Here, we review current and emerging approaches for visualizing and manipulating astrocyte activity in vivo. Deciphering how astrocyte network activity is controlled in different physiological and pathological contexts is critical for defining their roles in the healthy and diseased CNS. PMID:25665733

  3. Sweat pore reactivity as a surrogate measure of sympathetic nervous system activity in trauma-exposed individuals with and without posttraumatic stress disorder.

    Science.gov (United States)

    Familoni, Babajide O; Gregor, Kristin L; Dodson, Thomas S; Krzywicki, Alan T; Lowery, Bobby N; Orr, Scott P; Suvak, Michael K; Rasmusson, Ann M

    2016-09-01

    Stress analysis by FLIR (forward-looking infrared) evaluation (SAFE) has been demonstrated to monitor sweat pore activation (SPA) as a novel surrogate measure of sympathetic nervous system (SNS) activity in a normal population. SNS responses to a series of 15 1-s, 82 dB, white noise bursts were measured by skin conductance (SC) and SAFE monitoring of SPA on the fingers (FiP) and face (FaP) in 10 participants with posttraumatic stress disorder (PTSD) and 16 trauma-exposed participants without PTSD (Mage  = 48.92 ± 12.00 years; 26.9% female). Within participants, SC and FiP responses across trials were strongly correlated (r = .92, p < .001). Correlations between SC and FaP (r = .76, p = .001) and between FiP and FaP (r = .47, p = .005) were smaller. The habituation of SNS responses across the 15 trials was substantial (SC: d = -2.97; FiP: d = -2.34; FaP: d = -1.02). There was a strong correlation between habituation effects for SC and FiP (r = .76, p < .001), but not for SC and FaP (r = .15, p = .45) or FiP and FaP (r = .29, p = .16). Participants with PTSD showed larger SNS responses to the first loud noise than those without PTSD. PTSD reexperiencing symptoms assessed by the PTSD Checklist on the day of testing were associated with the SNS responses to the first loud noise measured by SC (d = 1.19) and FiP (d = .99), but not FaP (d = .10). This study confirms convergence of SAFE and SC as valid measures of SNS activity. SAFE FiP and SC responses were highly predictive of self-rated PTSD reexperiencing symptoms. SAFE may offer an attractive alternative for applications in PTSD and similar populations. © 2016 Society for Psychophysiological Research. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  4. Hyperpolarizing `α2'-adrenoceptors in rat sympathetic ganglia

    Science.gov (United States)

    Brown, D.A.; Caulfield, M.P.

    1979-01-01

    1 Receptors mediating catecholamine-induced hyperpolarization of isolated superior cervical sympathetic ganglia of the rat have been characterized by means of an extracellular recording method. 2 (-)-Noradrenaline (EC50, 1.7 ± 0.6 μM) produced an immediate low-amplitude (oxymetazoline (0.01 to 1 μM) and ergometrine (0.1 to 10 μM) produced a persistent, low-amplitude hyperpolarization, as though they were partial agonists. Responses to the agonists were blocked by yohimbine (1 μM) but not be prazosin (1 μM). 7 It is concluded that the adrenergic cell bodies in the ganglion were hyperpolarized through activation of the same type of α-receptor (`α2-receptors') as those present at adrenergic nerve terminals. PMID:218668

  5. Design of node record for fast active reflector

    International Nuclear Information System (INIS)

    Wu Wenqing; Luo Mingcheng; Tang Pengyi; Liu Jiajing; Wang Jian

    2014-01-01

    Active Reflector is the one of the innovations of Five hundred meter Aperture Spherical Telescope (FAST) whose performance touches on that of the overall telescope. Therefore a real time control system is needed by the Active Reflector System. In this paper, a new record type-node record is designed for EPICS-based active reflector control system of FAST, according to more than 2000 controlled node, which will be convenient for node management of IOC and prove the reusage of IOC codes. The record type is used in design of active reflector control system of FAST Miyun model. (authors)

  6. Record of principal work activities/deliverables

    International Nuclear Information System (INIS)

    1989-09-01

    Over the five year period of performance, thirteen task assignments were issued by the DOE to ARINC Research. During the two year base period seven tasks were assigned. Two task assignments were issued for each of the three consecutive one year option periods. Associated with all task assignments were multiple subtasks, some of which required significant effort. These subtasks are appropriately cited in this report under their respective task assignments as principal work activities or deliverables. The technical and management support provided to the DOE under this contract focused on two general areas: (1) appraisal activities and (2) non-appraisal activities. Support to appraisals included planning, document review, developing lines-of-inquiry, interviewing, data collection, report writing, and follow-up. Such work was executed both on-site at the DOE facility under review and off-site. Non-appraisal support was varied and included such areas as document review, data base development, technical assessments. statistical analysis, policy analysis, reliability engineering, and workshop and conference planning and execution

  7. [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.

  8. 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.)

  9. Diabetic cardiac autonomic dysfunction. Parasympathetic versus sympathetic

    Energy Technology Data Exchange (ETDEWEB)

    Uehara, Akihiko; Kurata, Chinori; Sugi, Toshihiko; Mikami, Tadashi; Shouda, Sakae [Hamamatsu Univ. School of Medicine, Shizuoka (Japan)

    1999-04-01

    Diabetic cardiac autonomic dysfunction often causes lethal arrhythmia and sudden cardiac death. {sup 123}I-Metaiodobenzylguanidine (MIBG) can evaluate cardiac sympathetic dysfunction, and analysis of heart rate variability (HRV) can reflect cardiac parasympathetic activity. We examined whether cardiac parasympathetic dysfunction assessed by HRV may correlate with sympathetic dysfunction assessed by MIBG in diabetic patients. In 24-hour electrocardiography, we analyzed 4 HRV parameters: high-frequency power (HF), HF in the early morning (EMHF), rMSSD and pNN50. MIBG planar images and SPECT were obtained 15 minutes (early) and 150 minutes (late) after injection and the heart washout rate was calculated. The defect score in 9 left ventricular regions was scored on a 4 point scale (0=normal - 3=severe defect). In 20 selected diabetic patients without congestive heart failure, coronary artery disease and renal failure, parasympathetic HRV parameters had a negative correlation with the sum of defect scores (DS) in the late images (R=-0.47 to -0.59, p<0.05) and some parameters had a negative correlation with the washout rate (R=-0.50 to -0.55, p<0.05). In a total of 64 diabetic patients also, these parameters had a negative correlation with late DS (R=-0.28 to -0.35, p<0.05) and early DS (R=-0.27 to -0.32, p<0.05). The progress of diabetic cardiac parasympathetic dysfunction may parallel the sympathetic one. (author)

  10. Effect of ghrelin on regulation of splenic sympathetic nerve discharge.

    Science.gov (United States)

    Balivada, Sivasai; Pawar, Hitesh N; Montgomery, Shawnee; Kenney, Michael J

    2016-12-01

    Ghrelin influences immune system function and modulates the sympathetic nervous system; however, the contribution of ghrelin to neural-immune interactions is not well-established because the effect of ghrelin on splenic sympathetic nerve discharge (SND) is not known. This study tested the hypothesis that central ghrelin administration would inhibit splenic SND in anesthetized rats. Rats received intracerebroventricular (ICV) injections of ghrelin (1nmol/kg) or aCSF. Lumbar SND recordings provided a non-visceral nerve control. The ICV ghrelin administration significantly increased splenic and lumbar SND, whereas mean arterial pressure (MAP) was not altered. These findings provide fundamental information regarding the nature of sympathetic-immune interactions. Published by Elsevier B.V.

  11. Microarray analysis reveals increased transcriptional repression and reduced metabolic activity but not major changes in the core apoptotic machinery during maturation of sympathetic neurons

    Directory of Open Access Journals (Sweden)

    Mikk eRaba

    2016-03-01

    Full Text Available Postnatal maturation of the neurons whose main phenotype and basic synaptic contacts are already established includes neuronal growth, refinement of synaptic contacts, final steps of differentiation, programmed cell death period (PCD etc. In the sympathetic neurons, postnatal maturation includes permanent end of the PCD that occurs with the same time schedule in vivo and in vitro suggesting that the process could be genetically determined. Also many other changes in the neuronal maturation could be permanent and thus based on stable changes in the genome expression. However, postnatal maturation of the neurons is poorly studied. Here we compared the gene expression profiles of immature and mature sympathetic neurons using Affymetrix microarray assay. We found 1310 significantly up-regulated and 1151 significantly down-regulated genes in the mature neurons. Gene ontology analysis reveals up-regulation of genes related to neuronal differentiation, chromatin and epigenetic changes, extracellular factors and their receptors, and cell adhesion, whereas many down-regulated genes were related to metabolic and biosynthetic processes. We show that termination of PCD is not related to major changes in the expression of classical genes for apoptosis or cell survival. Our dataset is deposited to the ArrayExpress database and is a valuable source to select candidate genes in the studies of neuronal maturation. As an example, we studied the changes in the expression of selected genes Igf2bp3, Coro1A, Zfp57, Dcx, and Apaf1 in the young and mature sympathetic ganglia by quantitative PCR and show that these were strongly downregulated in the mature ganglia.

  12. Nifedipine-sensitive blood pressure component in hypertensive models characterized by high activity of either sympathetic nervous system or renin-angiotensin system

    Czech Academy of Sciences Publication Activity Database

    Zicha, Josef; Dobešová, Zdenka; Behuliak, Michal; Pintérová, Mária; Kuneš, Jaroslav; Vaněčková, Ivana

    2014-01-01

    Roč. 63, č. 1 (2014), s. 13-26 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA305/09/0336; GA ČR(CZ) GAP304/12/0259 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : voltage-gated caclium channels * sympathetic nervous system * renin-angiotensin system * nitric oxide Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.293, year: 2014

  13. Detecting activation of the sympatho-adrenal axis from haemodynamic recordings, in conscious rabbits exposed to acute stress.

    Science.gov (United States)

    Roatta, S; Mohammed, M; Passatore, M

    2011-03-01

    When assessing sympathetic activation in acute stress, the attention is often limited to the sympatho-neural axis, whereas sympatho-adrenal activation, that can only be detected with poor time resolution from the concentration of plasma catecholamines, is often neglected. This study is aimed at re-investigating the role and the relevance of the sympatho-adrenal system in acute stress based on the analysis of haemodynamic responses in conscious rabbits. Experiments were carried out on 19 rabbits implanted with chronic probes for arterial blood pressure and for blood flow in the facial artery. Cardiovascular responses to a randomized sequence of acute stressors (pinprick, air jet, oscillation of the cage, inhalation of formaldehyde vapours and im injection of hypertonic saline) were recorded before and after α-adrenergic blockade (phentolamine) and unilateral section of the cervical sympathetic trunk (decentralization). Plasma catecholamine concentrations were analysed in four animals. All stressors induced an increase in arterial blood pressure and a reduction of vascular conductance in the facial artery ranging on average from 24% (pinprick) to 55% (box oscillation). Such vasoconstrictor response was abolished by phentolamine. In decentralized arteries, the vasoconstriction was delayed by 10-15 s and decreased in magnitude in a stressor-dependent way, indicating an adrenaline-mediated effect in the late phase of the stress response that was confirmed by changes in plasma adrenaline concentration. In conscious rabbits, rapid release of adrenaline makes a prominent contribution to vasoconstriction in response to different stressors including box oscillation, muscle pain and air jet but not the nasopharyngeal stimulation. © 2010 The Authors. Acta Physiologica © 2010 Scandinavian Physiological Society.

  14. Role of sympathetic nervous system and neuropeptides in obesity hypertension

    Directory of Open Access Journals (Sweden)

    J.E. Hall

    2000-06-01

    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

  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. Problems with extracellular recording of electrical activity in gastrointestinal muscle.

    Science.gov (United States)

    Sanders, Kenton M; Ward, Sean M; Hennig, Grant W

    2016-12-01

    Motility patterns of the gastrointestinal tract are important for efficient processing of nutrients and waste. Peristalsis and segmentation are based on rhythmic electrical slow waves that generate the phasic contractions fundamental to gastrointestinal motility. Slow waves are generated and propagated actively by interstitial cells of Cajal (ICC), and these events conduct to smooth muscle cells to elicit excitation-contraction coupling. Extracellular electrical recording has been utilized to characterize slow-wave generation and propagation and abnormalities that might be responsible for gastrointestinal motility disorders. Electrode array recording and digital processing are being used to generate data for models of electrical propagation in normal and pathophysiological conditions. Here, we discuss techniques of extracellular recording as applied to gastrointestinal organs and how mechanical artefacts might contaminate these recordings and confound their interpretation. Without rigorous controls for movement, current interpretations of extracellular recordings might ascribe inaccurate behaviours and electrical anomalies to ICC networks and gastrointestinal muscles, bringing into question the findings and validity of models of gastrointestinal electrophysiology developed from these recordings.

  17. 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.

  18. 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...

  19. Modulation of sympathetic outflow by centrally acting antihypertensive drugs

    NARCIS (Netherlands)

    van Zwieten, P. A.

    1996-01-01

    The modulation of peripheral sympathetic activity by the central nervous system (CNS) has been intensely investigated as a potential target of antihypertensive drugs. In particular, clonidine, guanfacine, and alpha-methyl-DOPA (acting via its metabolite alpha-methylnoradrenaline) have been developed

  20. Low-cost automatic activity data recording system

    Directory of Open Access Journals (Sweden)

    Moraes M.F.D.

    1997-01-01

    Full Text Available We describe a low-cost, high quality device capable of monitoring indirect activity by detecting touch-release events on a conducting surface, i.e., the animal's cage cover. In addition to the detecting sensor itself, the system includes an IBM PC interface for prompt data storage. The hardware/software design, while serving for other purposes, is used to record the circadian activity rhythm pattern of rats with time in an automated computerized fashion using minimal cost computer equipment (IBM PC XT. Once the sensor detects a touch-release action of the rat in the upper portion of the cage, the interface sends a command to the PC which records the time (hours-minutes-seconds when the activity occurred. As a result, the computer builds up several files (one per detector/sensor containing a time list of all recorded events. Data can be visualized in terms of actograms, indicating the number of detections per hour, and analyzed by mathematical tools such as Fast Fourier Transform (FFT or cosinor. In order to demonstrate method validation, an experiment was conducted on 8 Wistar rats under 12/12-h light/dark cycle conditions (lights on at 7:00 a.m.. Results show a biological validation of the method since it detected the presence of circadian activity rhythm patterns in the behavior of the rats

  1. 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.

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

    International Nuclear Information System (INIS)

    Shimojo, G.L.; Palma, R.K.; Brito, J.O.; Sanches, I.C.; Irigoyen, M.C.; De Angelis, K.

    2015-01-01

    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. [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.

  4. Physiological and pathophysiological interactions between the respiratory central pattern generator and the sympathetic nervous system.

    Science.gov (United States)

    Molkov, Yaroslav I; Zoccal, Daniel B; Baekey, David M; Abdala, Ana P L; Machado, Benedito H; Dick, Thomas E; Paton, Julian F R; Rybak, Ilya A

    2014-01-01

    Respiratory modulation seen in the sympathetic nerve activity (SNA) implies that the respiratory and sympathetic networks interact. During hypertension elicited by chronic intermittent hypoxia (CIH), the SNA displays an enhanced respiratory modulation reflecting strengthened interactions between the networks. In this chapter, we review a series of experimental and modeling studies that help elucidate possible mechanisms of sympatho-respiratory coupling. We conclude that this coupling significantly contributes to both the sympathetic baroreflex and the augmented sympathetic activity after exposure to CIH. This conclusion is based on the following findings. (1) Baroreceptor activation results in perturbation of the respiratory pattern via transient activation of postinspiratory neurons in the Bötzinger complex (BötC). The same BötC neurons are involved in the respiratory modulation of SNA, and hence provide an additional pathway for the sympathetic baroreflex. (2) Under hypercapnia, phasic activation of abdominal motor nerves (AbN) is accompanied by synchronous discharges in SNA due to the common source of this rhythmic activity in the retrotrapezoid nucleus (RTN). CIH conditioning increases the CO2 sensitivity of central chemoreceptors in the RTN which results in the emergence of AbN and SNA discharges under normocapnic conditions similar to those observed during hypercapnia in naïve animals. Thus, respiratory-sympathetic interactions play an important role in defining sympathetic output and significantly contribute to the sympathetic activity and hypertension under certain physiological or pathophysiological conditions, and the theoretical framework presented may be instrumental in understanding of malfunctioning control of sympathetic activity in a variety of disease states. © 2014 Elsevier B.V. All rights reserved.

  5. [Reflex sympathetic dystrophy involving the ankle in pregnancy: characteristics and therapeutic management].

    Science.gov (United States)

    Sergent, F; Mouroko, D; Sellam, R; Marpeau, L

    2003-06-01

    We report the case of a multigravida presenting in the first trimester of pregnancy with reflex sympathetic dystrophy involving both ankles. Preferential location of reflex sympathetic dystrophy in pregnancy is classically the hip (9 times out of 10). Symptoms develop mostly with primipara in the third trimester of pregnancy or in post-partum. Fracture is the major risk of reflex sympathetic dystrophy. Peculiarities of reflex sympathetic dystrophy's treatment in the course of pregnancy are evoked. The end of the pregnancy can be shortened with the aim of stabilizing disease even to activate its healing. Pathophysiologic mechanisms of reflex sympathetic dystrophy in pregnancy seem multiple and complex. Our observation, by its atypical characteristics, recalls it.

  6. Regional sympathetic denervation after myocardial infarction in humans detected noninvasively using I-123-metaiodobenzylguanidine

    Energy Technology Data Exchange (ETDEWEB)

    Stanton, M.S.; Tuli, M.M.; Radtke, N.L.; Heger, J.J.; Miles, W.M.; Mock, B.H.; Burt, R.W.; Wellman, H.N.; Zipes, D.P. (Indiana Univ. School of Medicine, IN (USA))

    1989-11-15

    Transmural myocardial infarction in dogs produces denervation of sympathetic nerves in viable myocardium apical to the infarct that may be arrhythmogenic. It is unknown whether sympathetic denervation occurs in humans. The purpose of this study was to use iodine-123-metaiodobenzylguanidine (MIBG), a radiolabeled guanethidine analog that is actively taken up by sympathetic nerve terminals, to image noninvasively the cardiac sympathetic nerves in patients with and without ventricular arrhythmias after myocardial infarction. Results showed that 10 of 12 patients with spontaneous ventricular tachyarrhythmias after myocardial infarction exhibited regions of thallium-201 uptake indicating viable perfused myocardium, with no MIBG uptake. Such a finding is consistent with sympathetic denervation. One patient had frequent episodes of nonsustained ventricular tachycardia induced at exercise testing that was eliminated by beta-adrenoceptor blockade. Eleven of the 12 patients had ventricular tachycardia induced at electrophysiologic study and metoprolol never prevented induction. Sympathetic denervation was also detected in two of seven postinfarction patients without ventricular arrhythmias. Normal control subjects had no regions lacking MIBG uptake. This study provides evidence that regional sympathetic denervation occurs in humans after myocardial infarction and can be detected noninvasively by comparing MIBG and thallium-201 images. Although the presence of sympathetic denervation may be related to the onset of spontaneous ventricular tachyarrhythmias in some patients, it does not appear to be related to sustained ventricular tachycardia induced at electrophysiologic study.

  7. Arrhythmogenic effect of sympathetic histamine in mouse hearts subjected to acute ischemia.

    Science.gov (United States)

    He, Gonghao; Hu, Jing; Li, Teng; Ma, Xue; Meng, Jingru; Jia, Min; Lu, Jun; Ohtsu, Hiroshi; Chen, Zhong; Luo, Xiaoxing

    2012-02-10

    The role of histamine as a newly recognized sympathetic neurotransmitter has been presented previously, and its postsynaptic effects greatly depended on the activities of sympathetic nerves. Cardiac sympathetic nerves become overactivated under acute myocardial ischemic conditions and release neurotransmitters in large amounts, inducing ventricular arrhythmia. Therefore, it is proposed that cardiac sympathetic histamine, in addition to norepinephrine, may have a significant arrhythmogenic effect. To test this hypothesis, we observed the release of cardiac sympathetic histamine and associated ventricular arrhythmogenesis that was induced by acute ischemia in isolated mouse hearts. Mast cell-deficient mice (MCDM) and histidine decarboxylase knockout (HDC(-/-)) mice were used to exclude the potential involvement of mast cells. Electrical field stimulation and acute ischemia-reperfusion evoked chemical sympathectomy-sensitive histamine release from the hearts of both MCDM and wild-type (WT) mice but not from HDC(-/-) mice. The release of histamine from the hearts of MCDM and WT mice was associated with the development of acute ischemia-induced ventricular tachycardia and ventricular fibrillation. The incidence and duration of induced ventricular arrhythmias were found to decrease in the presence of the selective histamine H(2) receptor antagonist famotidine. Additionally, the released histamine facilitated the arrhythmogenic effect of simultaneously released norepinephrine. We conclude that, under acute ischemic conditions, cardiac sympathetic histamine released by overactive sympathetic nerve terminals plays a certain arrhythmogenic role via H(2) receptors. These findings provided novel insight into the pathophysiological roles of sympathetic histamine, which may be a new therapeutic target for acute ischemia-induced arrhythmias.

  8. Time Multiplexed Active Neural Probe with 1356 Parallel Recording Sites

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    Bogdan C. Raducanu

    2017-10-01

    Full Text Available We present a high electrode density and high channel count CMOS (complementary metal-oxide-semiconductor active neural probe containing 1344 neuron sized recording pixels (20 µm × 20 µm and 12 reference pixels (20 µm × 80 µm, densely packed on a 50 µm thick, 100 µm wide, and 8 mm long shank. The active electrodes or pixels consist of dedicated in-situ circuits for signal source amplification, which are directly located under each electrode. The probe supports the simultaneous recording of all 1356 electrodes with sufficient signal to noise ratio for typical neuroscience applications. For enhanced performance, further noise reduction can be achieved while using half of the electrodes (678. Both of these numbers considerably surpass the state-of-the art active neural probes in both electrode count and number of recording channels. The measured input referred noise in the action potential band is 12.4 µVrms, while using 678 electrodes, with just 3 µW power dissipation per pixel and 45 µW per read-out channel (including data transmission.

  9. Spinal Cord Injury-Induced Dysautonomia via Plasticity in Paravertebral Sympathetic Postganglionic

    Science.gov (United States)

    2016-10-01

    therefore assume that our new whole cell recordings are closer to physiological reality . (B) Synaptic and anatomical properties of thoracic...2015) Virtual leak channels modulate firing dynamics and synaptic integration in rat sympathetic neurons: implications for ganglionic transmission in...Neurosci. Abst. 42 (2016). 2. Halder, M.C., M.; MacDowell, C.; McKinnon, M.; Sawchuk,M.; Hochman,S. (2016). Anatomy of mouse thoracic sympathetic chain

  10. [Reflex sympathetic dystrophy of childhood: one case].

    Science.gov (United States)

    Jouary, T; Boralevi, F; Pillet, P; Taieb, A; Léauté-Labrèze, C

    2002-10-01

    Reflex sympathetic dystrophy (Complex Regional Pain Syndrome type 1) is little known by dermatologists. We report a pediatric case of reflex sympathetic dystrophy with predominant cutaneous involvement. A 10 year-old girl presented a warm, painful and relapsing right hand edema for seven months (three outbreaks). The hand was cyanotic, pigmented and painful. Routine blood tests were normal. Radiography and radionuclide bone scan were consistent with stage 1 reflex sympathetic dystrophy. Physiotherapy led to dramatic improvement. Reflex sympathetic dystrophy is known since the XVIIIth century. In the last decade, progress in radiology and bone scan have provided elements for understanding the physiopathology of the disease. Microvascular abnormalities under the control of sympathetic nervous system are characteristic of different stages of reflex sympathetic dystrophy. Recently, neurovascular system experiments showed that sympathetic reflex tonus changes may be controlled by the central nervous system. Dermatologic changes of reflex sympathetic dystrophy are well known: edema and erythema in first stage, cyanosis in second stage, sclerosis and atrophia in third stage, but pediatric cases are rarely reported. Reflex sympathetic dystrophy is a complex disease, however its physiopathology is now understood. The clinical presentation can be atypical and the dermatologist may be the first to be consulted.

  11. Renal sympathetic nerve, blood flow, and epithelial transport responses to thermal stress.

    Science.gov (United States)

    Wilson, Thad E

    2017-05-01

    Thermal stress is a profound sympathetic stress in humans; kidney responses involve altered renal sympathetic nerve activity (RSNA), renal blood flow, and renal epithelial transport. During mild cold stress, RSNA spectral power but not total activity is altered, renal blood flow is maintained or decreased, and epithelial transport is altered consistent with a sympathetic stress coupled with central volume loaded state. Hypothermia decreases RSNA, renal blood flow, and epithelial transport. During mild heat stress, RSNA is increased, renal blood flow is decreased, and epithelial transport is increased consistent with a sympathetic stress coupled with a central volume unloaded state. Hyperthermia extends these directional changes, until heat illness results. Because kidney responses are very difficult to study in humans in vivo, this review describes and qualitatively evaluates an in vivo human skin model of sympathetically regulated epithelial tissue compared to that of the nephron. This model utilizes skin responses to thermal stress, involving 1) increased skin sympathetic nerve activity (SSNA), decreased skin blood flow, and suppressed eccrine epithelial transport during cold stress; and 2) increased SSNA, skin blood flow, and eccrine epithelial transport during heat stress. This model appears to mimic aspects of the renal responses. Investigations of skin responses, which parallel certain renal responses, may aid understanding of epithelial-sympathetic nervous system interactions during cold and heat stress. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Relationship between three phase bone scintigram and prognosis after sympathetic blockade in reflex sympathetic dystrophy of the hand

    Energy Technology Data Exchange (ETDEWEB)

    Yokono, Atsuko; Yokono, Satoshi; Oguri, Kenji (Kagawa Medical School, Miki (Japan))

    1990-11-01

    The authors attempted to correlate the changes in three phase bone scintigram (TPBS) with prognosis after sympathetic blockade in reflex sympathetic dystrophy (RSD) of the hand. Subjects were 12 patients of RSD in acute or dystrophic stage, who all had increased images on TPBS. Either intravenous regional sympathectomy with guanethidine or stellate ganglion block was performed repeatedly. We compared TPBS obtained just before and after this series of sympathetic blocks and evaluated the eventual recovery of function of the hand. In 8 patients, blood flow (phase 1) image of TPBS decreased after the blockade. Of these patients, those who showed almost normalized tracer activity not only on flow image but on blood pool (phase 2) and delayed (phase 3) image, returned to normal. But others with normalized blood flow and still increased activity in blood pool and delayed image, remained with mild contracture of the hand. These results suggest that normalization of blood pool and delayed image on TPBS is a predictor of subsequent recovery after sympathetic blockade in RSD. (author).

  13. Sympathetic Nervous System Synchrony in Couple Therapy.

    Science.gov (United States)

    Karvonen, Anu; Kykyri, Virpi-Liisa; Kaartinen, Jukka; Penttonen, Markku; Seikkula, Jaakko

    2016-07-01

    The aim of this study was to test whether there is statistically significant sympathetic nervous system (SNS) synchrony between participants in couple therapy. To our knowledge, this is the first study to measure psychophysiological synchrony during therapy in a multiactor setting. The study focuses on electrodermal activity (EDA) in the second couple therapy session from 10 different cases (20 clients, 10 therapists working in pairs). The EDA concordance index was used as a measure of SNS synchrony between dyads, and synchrony was found in 85% of all the dyads. Surprisingly, co-therapists exhibited the highest levels of synchrony, whereas couples exhibited the lowest synchrony. The client-therapist synchrony was lower than that of the co-therapists, but higher than that of the couples. A Video Abstract is available next to the online version of this article on the JMFT web site. © 2016 American Association for Marriage and Family Therapy.

  14. Nitric Oxide Orchestrates a Power-Law Modulation of Sympathetic Firing Behaviors in Neonatal Rat Spinal Cords

    Directory of Open Access Journals (Sweden)

    Chun-Kuei Su

    2018-03-01

    Full Text Available Nitric oxide (NO is a diffusible gas and has multifarious effects on both pre- and postsynaptic events. As a consequence of complex excitatory and inhibitory integrations, NO effects on neuronal activities are heterogeneous. Using in vitro preparations of neonatal rats that retain the splanchnic sympathetic nerves and the thoracic spinal cord as an experimental model, we report here that either enhancement or attenuation of NO production in the neonatal rat spinal cords could increase, decrease, or not change the spontaneous firing behaviors recorded from splanchnic sympathetic single fibers. To elucidate the mathematical features of NO-mediated heterogeneous responses, the ratios of changes in firing were plotted against their original firing rates. In log-log plots, a linear data distribution demonstrated that NO-mediated heterogeneity in sympathetic firing responses was well described by a power function. Selective antagonists were applied to test if glycinergic, GABAergic, glutamatergic, and cholinergic neurotransmission in the spinal cord are involved in NO-mediated power-law firing modulations (plFM. NO-mediated plFM diminished in the presence of mecamylamine (an open-channel blocker of nicotinic cholinergic receptors, indicating that endogenous nicotinic receptor activities were essential for plFM. Applications of strychnine (a glycine receptor blocker, gabazine (a GABAA receptor blocker, or kynurenate (a broad-spectrum ionotropic glutamate receptor blocker also caused plFM. However, strychnine- or kynurenate-induced plFM was diminished by L-NAME (an NO synthase inhibitor pretreatments, indicating that the involvements of glycine or ionotropic glutamate receptor activities in plFM were secondary to NO signaling. To recapitulate the arithmetic natures of the plFM, the plFM were simulated by firing changes in two components: a step increment and a fractional reduction of their basal firing activities. Ionotropic glutamate receptor

  15. Nitric Oxide Orchestrates a Power-Law Modulation of Sympathetic Firing Behaviors in Neonatal Rat Spinal Cords.

    Science.gov (United States)

    Su, Chun-Kuei; Chen, Yi-Yin; Ho, Chiu-Ming

    2018-01-01

    Nitric oxide (NO) is a diffusible gas and has multifarious effects on both pre- and postsynaptic events. As a consequence of complex excitatory and inhibitory integrations, NO effects on neuronal activities are heterogeneous. Using in vitro preparations of neonatal rats that retain the splanchnic sympathetic nerves and the thoracic spinal cord as an experimental model, we report here that either enhancement or attenuation of NO production in the neonatal rat spinal cords could increase, decrease, or not change the spontaneous firing behaviors recorded from splanchnic sympathetic single fibers. To elucidate the mathematical features of NO-mediated heterogeneous responses, the ratios of changes in firing were plotted against their original firing rates. In log-log plots, a linear data distribution demonstrated that NO-mediated heterogeneity in sympathetic firing responses was well described by a power function. Selective antagonists were applied to test if glycinergic, GABAergic, glutamatergic, and cholinergic neurotransmission in the spinal cord are involved in NO-mediated power-law firing modulations (plFM). NO-mediated plFM diminished in the presence of mecamylamine (an open-channel blocker of nicotinic cholinergic receptors), indicating that endogenous nicotinic receptor activities were essential for plFM. Applications of strychnine (a glycine receptor blocker), gabazine (a GABA A receptor blocker), or kynurenate (a broad-spectrum ionotropic glutamate receptor blocker) also caused plFM. However, strychnine- or kynurenate-induced plFM was diminished by L-NAME (an NO synthase inhibitor) pretreatments, indicating that the involvements of glycine or ionotropic glutamate receptor activities in plFM were secondary to NO signaling. To recapitulate the arithmetic natures of the plFM, the plFM were simulated by firing changes in two components: a step increment and a fractional reduction of their basal firing activities. Ionotropic glutamate receptor activities were found

  16. Sympathetic Overactivity in Chronic Kidney Disease: Consequences and Mechanisms

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    Jasdeep Kaur

    2017-08-01

    Full Text Available The incidence of chronic kidney disease (CKD is increasing worldwide, with more than 26 million people suffering from CKD in the United States alone. More patients with CKD die of cardiovascular complications than progress to dialysis. Over 80% of CKD patients have hypertension, which is associated with increased risk of cardiovascular morbidity and mortality. Another common, perhaps underappreciated, feature of CKD is an overactive sympathetic nervous system. This elevation in sympathetic nerve activity (SNA not only contributes to hypertension but also plays a detrimental role in the progression of CKD independent of any increase in blood pressure. Indeed, high SNA is associated with poor prognosis and increased cardiovascular morbidity and mortality independent of its effect on blood pressure. This brief review will discuss some of the consequences of sympathetic overactivity and highlight some of the potential pathways contributing to chronically elevated SNA in CKD. Mechanisms leading to chronic sympathoexcitation in CKD are complex, multifactorial and to date, not completely understood. Identification of the mechanisms and/or signals leading to sympathetic overactivity in CKD are crucial for development of effective therapeutic targets to reduce the increased cardiovascular risk in this patient group.

  17. 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.

  18. Polysialic Acid Regulates Sympathetic Outflow by Facilitating Information Transfer within the Nucleus of the Solitary Tract.

    Science.gov (United States)

    Bokiniec, Phillip; Shahbazian, Shila; McDougall, Stuart J; Berning, Britt A; Cheng, Delfine; Llewellyn-Smith, Ida J; Burke, Peter G R; McMullan, Simon; Mühlenhoff, Martina; Hildebrandt, Herbert; Braet, Filip; Connor, Mark; Packer, Nicolle H; Goodchild, Ann K

    2017-07-05

    Expression of the large extracellular glycan, polysialic acid (polySia), is restricted in the adult, to brain regions exhibiting high levels of plasticity or remodeling, including the hippocampus, prefrontal cortex, and the nucleus of the solitary tract (NTS). The NTS, located in the dorsal brainstem, receives constant viscerosensory afferent traffic as well as input from central regions controlling sympathetic nerve activity, respiration, gastrointestinal functions, hormonal release, and behavior. Our aims were to determine the ultrastructural location of polySia in the NTS and the functional effects of enzymatic removal of polySia, both in vitro and in vivo polySia immunoreactivity was found throughout the adult rat NTS. Electron microscopy demonstrated polySia at sites that influence neurotransmission: the extracellular space, fine astrocytic processes, and neuronal terminals. Removing polySia from the NTS had functional consequences. Whole-cell electrophysiological recordings revealed altered intrinsic membrane properties, enhancing voltage-gated K + currents and increasing intracellular Ca 2+ Viscerosensory afferent processing was also disrupted, dampening low-frequency excitatory input and potentiating high-frequency sustained currents at second-order neurons. Removal of polySia in the NTS of anesthetized rats increased sympathetic nerve activity, whereas functionally related enzymes that do not alter polySia expression had little effect. These data indicate that polySia is required for the normal transmission of information through the NTS and that changes in its expression alter sympathetic outflow. polySia is abundant in multiple but discrete brain regions, including sensory nuclei, in both the adult rat and human, where it may regulate neuronal function by mechanisms identified here. SIGNIFICANCE STATEMENT All cells are coated in glycans (sugars) existing predominantly as glycolipids, proteoglycans, or glycoproteins formed by the most complex form of

  19. [ Sudeck's bone atrophy (reflex sympathetic dystrophy)].

    Science.gov (United States)

    Hayashi, Yasufumi

    2008-07-01

    Reflex sympathetic dystrophy is a disease clinically characterized severe pain, allodynia (severe pain caused by a touch) and over-reaction of pain sensation after a minor injury. In 1994, reflex sympathetic dystrophy was given a name of complex regional pain syndrome type 1 by a international congress, because local blockade of the sympathetic nerve has not been found to be invariably effective. Treatment system for reflex sympathetic dystrophy is composed of medicament therapy including oral administration and/or injection of drug, physical therapy such as thermotherapy and gently passive movement, surgical treatment and psychotherapy. Treatment with injection of pamidronate for 23 patients with reflex sympathetic dystrophy revealed to reduced the grade of pain to two third compared to pre-treatment period, and local intravenous block with local anesthetic drug and steroid hormone disappeared the almost symptoms in cases of early phase.

  20. Cardiac sympathetic imaging with mIBG in cirrhosis and portal hypertension

    DEFF Research Database (Denmark)

    Møller, Søren; Mortensen, Christian; Bendtsen, Flemming

    2012-01-01

    Autonomic and cardiac dysfunction is frequent in cirrhosis and includes increased sympathetic nervous activity, impaired heart rate variability (HRV), and baroreflex sensitivity (BRS). Quantified (123)I-metaiodobenzylguanidine (mIBG) scintigraphy reflects cardiac noradrenaline uptake, and in pati......Autonomic and cardiac dysfunction is frequent in cirrhosis and includes increased sympathetic nervous activity, impaired heart rate variability (HRV), and baroreflex sensitivity (BRS). Quantified (123)I-metaiodobenzylguanidine (mIBG) scintigraphy reflects cardiac noradrenaline uptake...

  1. Comparable attenuation of sympathetic nervous system activity in obese subjects with normal glucose tolerance, impaired glucose tolerance and treatment naïve type 2 diabetes following equivalent weight loss

    Directory of Open Access Journals (Sweden)

    Nora E. Straznicky

    2016-11-01

    Full Text Available Background and Purpose: Elevated sympathetic nervous system (SNS activity is a characteristic of obesity and type 2 diabetes (T2D that contributes to target organ damage and cardiovascular risk. In this study we examined whether baseline metabolic status influences the degree of sympathoinhibition attained following equivalent dietary weight loss. Methods: Un-medicated obese individuals categorized as normal glucose tolerant (NGT, n=15, impaired glucose tolerant (IGT, n=24 and newly-diagnosed T2D (n=15 consumed a hypocaloric diet (29% fat, 23% protein, 45% carbohydrate for 4-months. The three groups were matched for baseline age (56 + 1 years, body mass index (BMI, 32.9 + 0.7 kg/m2 and gender. Clinical measurements included whole-body norepinephrine kinetics, muscle sympathetic nerve activity (MSNA, by microneurography, spontaneous cardiac baroreflex sensitivity (BRS and oral glucose tolerance test. Results: Weight loss averaged -7.5 + 0.8, -8.1 + 0.5 and -8.0 + 0.9 % of body weight in NGT, IGT and T2D groups, respectively. T2D subjects had significantly greater reductions in fasting glucose, 2-h glucose and glucose area under the curve (AUC0-120 compared to NGT and IGT (group effect, P<0.001. Insulinogenic index decreased in IGT and NGT groups and increased in T2D (group x time, P=0.04. The magnitude of reduction in MSNA (-7 + 3, -8 + 4, -15 + 4 burst/100hb, respectively and whole-body norepinephrine spillover rate (-28 + 8, -18 + 6 and -25 + 7 %, respectively, time effect both P<0.001, did not differ between groups. After adjustment for age and change in body weight, ∆ insulin AUC0-120 was independently associated with reduction in arterial norepinephrine concentration, whilst ∆ LDL-cholesterol and improvement in BRS were independently associated with decrease in MSNA. Conclusions: Equivalent weight loss through hypocaloric diet is accompanied by similar sympathoinhibition in matched obese subjects with different baseline glucose tolerance

  2. RESTING SYMPATHETIC BAROREFLEX SENSITIVITY IN SUBJECTS WITH LOW AND HIGH TOLERANCE TO CENTRAL HYPOVOLEMIA INDUCED BY LOWER BODY NEGATIVE PRESSURE

    Directory of Open Access Journals (Sweden)

    Carmen eHinojosa-Laborde

    2014-06-01

    Full Text Available Central hypovolemia elicited by orthostasis or hemorrhage triggers sympathetically-mediated baroreflex responses to maintain organ perfusion; these reflexes are less sensitive in patients with orthostatic intolerance, and during conditions of severe blood loss, may result in cardiovascular collapse (decompensatory or circulatory shock. The ability to tolerate central hypovolemia is variable and physiological factors contributing to tolerance are emerging. We tested the hypothesis that resting muscle sympathetic nerve activity (MSNA and sympathetic baroreflex sensitivity (BRS are attenuated in male and female subjects who have low tolerance (LT to central hypovolemia induced by lower body negative pressure (LBNP. MSNA and diastolic arterial pressure (DAP were recorded in 47 human subjects who subsequently underwent LBNP to tolerance (onset of presyncopal symptoms. LT subjects experienced presyncopal symptoms prior to completing LBNP of -60 mm Hg, and subjects with high tolerance (HT experienced presyncopal symptoms after completing LBNP after -60 mmHg. Contrary to our hypothesis, resting MSNA burst incidence was not different between LT and HT subjects, and was not related to time to presyncope. BRS was assessed as the slope of the relationship between spontaneous fluctuations in DAP and MSNA during 5 min of supine rest. MSNA burst incidence/DAP correlations were greater than or equal to 0.5 in 37 subjects (LT: n= 9; HT: n=28, and BRS was not different between LT and HT (-1.8 ± 0.3 vs. -2.2 ± 0.2 bursts•(100 beats-1•mmHg-1, p=0.29. We conclude that tolerance to central hypovolemia is not related to either resting MSNA or sympathetic BRS.

  3. Numerical modeling of sympathetic detonation

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, A.L.; Kershner, J.D.; Mader, C.L.

    1979-11-01

    The sympathetic detonation of small cubes of solid rocket propellant was modeled numerically, using the Eulerian reactive hydrodynamic code 2DE with Forest Fire burn rates. The model was applied to cubes of 1 to 3 in., with excellent agreement between calculated and experimental results. The model also was applied to several propellants and to different experimental arrangements. The blast-wave pressures in the air gap and the induced shock pressures in the acceptor were obtained from the model. The correlation between these pressures was coupled with a study of the effect of the length-to-diameter ratio of a donor cylinder and the necessary conditions for detonation of the acceptor to provide a semiquantitative predictive capability.

  4. Use of polyurethane foam deformation sensor to record respiratory activity

    Science.gov (United States)

    Bredov, V. I.; Baranov, V. S.

    1980-05-01

    The sensor developed has some substantial advantages over other known types. It is highly sensitive over a wide range of strain loads. The level of the output signal is linearly related to the force exerted on it, and it is sufficient for direct recording without using amplifiers of electric signals. The sensor is based on elastic, spongy material, polyurethane foam (porolon) with current-conducting material on the pore surface, current-conducting carbon black or electrode paste. The elastic properties of the sensor are built in the actual base of the strain-sensitive element, which simplifies the construction substantially and increases the reliability of the unit. In order to test the possibility of using this sensor to examine respiratory function, human pneumograms were recorded with the subject in a calm state along with the respiratory activity of experimental animals (dogs). Samples of the respiratory curve are shown. The simplicity of design of the sensor makes it possible to use it in various physiological experiments.

  5. Responses of muscle spindles in feline dorsal neck muscles to electrical stimulation of the cervical sympathetic nerve.

    Science.gov (United States)

    Hellström, F; Roatta, S; Thunberg, J; Passatore, M; Djupsjöbacka, M

    2005-09-01

    Previous studies performed in jaw muscles of rabbits and rats have demonstrated that sympathetic outflow may affect the activity of muscle spindle afferents (MSAs). The resulting impairment of MSA information has been suggested to be involved in the genesis and spread of chronic muscle pain. The present study was designed to investigate sympathetic influences on muscle spindles in feline trapezius and splenius muscles (TrSp), as these muscles are commonly affected by chronic pain in humans. Experiments were carried out in cats anesthetized with alpha-chloralose. The effect of electrical stimulation (10 Hz for 90 s or 3 Hz for 5 min) of the peripheral stump of the cervical sympathetic nerve (CSN) was investigated on the discharge of TrSp MSAs (units classified as Ia-like and II-like) and on their responses to sinusoidal stretching of these muscles. In some of the experiments, the local microcirculation of the muscles was monitored by laser Doppler flowmetry. In total, 46 MSAs were recorded. Stimulation of the CSN at 10 Hz powerfully depressed the mean discharge rate of the majority of the tested MSAs (73%) and also affected the sensitivity of MSAs to sinusoidal changes of muscle length, which were evaluated in terms of amplitude and phase of the sinusoidal fitting of unitary activity. The amplitude was significantly reduced in Ia-like units and variably affected in II-like units, while in general the phase was affected little and not changed significantly in either group. The discharge of a smaller percentage of tested units was also modulated by 3-Hz CSN stimulation. Blockade of the neuromuscular junctions by pancuronium did not induce any changes in MSA responses to CSN stimulation, showing that these responses were not secondary to changes in extrafusal or fusimotor activity. Further data showed that the sympathetically induced modulation of MSA discharge was not secondary to the concomitant reduction of muscle blood flow induced by the stimulation. Hence

  6. 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)

    Harada, Kenji; Nomura, Masahiro; Nishikado, Akiyoshi; Uehara, Kouzoh; Nakaya, Yutaka; Ito, Susumu

    2003-01-01

    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 123 I-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)

  7. Short-Term Red Wine Consumption Promotes Differential Effects on Plasma Levels of High-Density Lipoprotein Cholesterol, Sympathetic Activity, and Endothelial Function in Hypercholesterolemic, Hypertensive, and Healthy Subjects

    Science.gov (United States)

    Andrade, Ana CM; Cesena, Fernando HY; Consolim-Colombo, Fernanda M; Coimbra, Silmara R; Benjó, Alexandre M; Krieger, Eduardo M; da Luz, Protasio Lemos

    2009-01-01

    OBJECTIVES: To compare the metabolic, hemodynamic, autonomic, and endothelial responses to short-term red wine consumption in subjects with hypercholesterolemia or arterial hypertension, and healthy controls. METHODS: Subjects with hypercholesterolemia (n=10) or arterial hypertension (n=9), or healthy controls (n=7) were given red wine (250 mL/night) for 15 days. Analyses were performed before and after red wine intake. RESULTS: Red wine significantly increased the plasma levels of HDL-cholesterol in the controls, but not in the other groups. The effects on hemodynamic measurements were mild, non-significantly more prominent in healthy subjects, and exhibited high interindividual variability. Across all participants, mean blood pressure decreased 7 mmHg (p <0.01) and systemic vascular resistance decreased 7% (p = 0.05). Heart rate and cardiac output did not significantly change in any group. Red wine enhanced muscle sympathetic fibular nerve activity in hypercholesterolemic and hypertensive patients, but not in controls. At baseline, brachial artery flow-mediated dilation was impaired in patients with hypercholesterolemia and arterial hypertension; red wine restored the dilation in the hypercholesterolemic group but not in the hypertensive group. CONCLUSIONS: Red wine elicits different metabolic, autonomic, and endothelial responses among individuals with hypercholesterolemia or arterial hypertension and healthy controls. Our findings highlight the need to consider patient characteristics when evaluating the response to red wine. PMID:19488610

  8. Short-term red wine consumption promotes differential effects on plasma levels of high-density lipoprotein cholesterol, sympathetic activity, and endothelial function in hypercholesterolemic, hypertensive, and healthy subjects

    Directory of Open Access Journals (Sweden)

    Ana CM Andrade

    2009-05-01

    Full Text Available OBJECTIVES: To compare the metabolic, hemodynamic, autonomic, and endothelial responses to short-term red wine consumption in subjects with hypercholesterolemia or arterial hypertension, and healthy controls. METHODS: Subjects with hypercholesterolemia (n=10 or arterial hypertension (n=9, or healthy controls (n=7 were given red wine (250 mL/night for 15 days. Analyses were performed before and after red wine intake. RESULTS: Red wine significantly increased the plasma levels of HDL-cholesterol in the controls, but not in the other groups. The effects on hemodynamic measurements were mild, non-significantly more prominent in healthy subjects, and exhibited high interindividual variability. Across all participants, mean blood pressure decreased 7 mmHg (p <0.01 and systemic vascular resistance decreased 7% (p = 0.05. Heart rate and cardiac output did not significantly change in any group. Red wine enhanced muscle sympathetic fibular nerve activity in hypercholesterolemic and hypertensive patients, but not in controls. At baseline, brachial artery flow-mediated dilation was impaired in patients with hypercholesterolemia and arterial hypertension; red wine restored the dilation in the hypercholesterolemic group but not in the hypertensive group. CONCLUSIONS: Red wine elicits different metabolic, autonomic, and endothelial responses among individuals with hypercholesterolemia or arterial hypertension and healthy controls. Our findings highlight the need to consider patient characteristics when evaluating the response to red wine.

  9. Pathophysiology of Resistant Hypertension: The Role of Sympathetic Nervous System

    OpenAIRE

    Tsioufis, Costas; Kordalis, Athanasios; Flessas, Dimitris; Anastasopoulos, Ioannis; Tsiachris, Dimitris; Papademetriou, Vasilios; Stefanadis, Christodoulos

    2011-01-01

    Resistant hypertension (RH) is a powerful risk factor for cardiovascular morbidity and mortality. Among the characteristics of patients with RH, obesity, obstructive sleep apnea, and aldosterone excess are covering a great area of the mosaic of RH phenotype. Increased sympathetic nervous system (SNS) activity is present in all these underlying conditions, supporting its crucial role in the pathophysiology of antihypertensive treatment resistance. Current clinical and experimental knowledge po...

  10. 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

  11. Factitious lymphoedema as a psychiatric condition mimicking reflex sympathetic dystrophy: a case report.

    Science.gov (United States)

    Nwaejike, Nnamdi; Archbold, Hap; Wilson, Darrin S

    2008-06-24

    Reflex sympathetic dystrophy can result in severe disability with only one in five patients able to fully resume prior activities. Therefore, it is important to diagnose this condition early and begin appropriate treatment. Factitious lymphoedema can mimic reflex sympathetic dystrophy and is caused by self-inflicted tourniquets, blows to the arm or repeated skin irritation. Patients with factitious lymphoedema have an underlying psychiatric disorder but usually present to emergency or orthopaedics departments. Factitious lymphoedema can then be misdiagnosed as reflex sympathetic dystrophy. The treatment for factitious lymphoedema is dealing with the underlying psychiatric condition. We share our experience of treating a 33-year-old man, who presented with factitious lymphoedema, initially diagnosed as reflex sympathetic dystrophy. Awareness of this very similar differential diagnosis allows early appropriate treatment to be administered.

  12. Factitious lymphoedema as a psychiatric condition mimicking reflex sympathetic dystrophy: a case report

    Directory of Open Access Journals (Sweden)

    Nwaejike Nnamdi

    2008-06-01

    Full Text Available Abstract Introduction Reflex sympathetic dystrophy can result in severe disability with only one in five patients able to fully resume prior activities. Therefore, it is important to diagnose this condition early and begin appropriate treatment. Factitious lymphoedema can mimic reflex sympathetic dystrophy and is caused by self-inflicted tourniquets, blows to the arm or repeated skin irritation. Patients with factitious lymphoedema have an underlying psychiatric disorder but usually present to emergency or orthopaedics departments. Factitious lymphoedema can then be misdiagnosed as reflex sympathetic dystrophy. The treatment for factitious lymphoedema is dealing with the underlying psychiatric condition. Case presentation We share our experience of treating a 33-year-old man, who presented with factitious lymphoedema, initially diagnosed as reflex sympathetic dystrophy. Conclusion Awareness of this very similar differential diagnosis allows early appropriate treatment to be administered.

  13. Sympathetic Cooling of Trapped Cd+ Isotopes

    OpenAIRE

    Blinov, B. B.; Deslauriers, L.; Lee, P.; Madsen, M. J.; Miller, R.; Monroe, C.

    2001-01-01

    We sympathetically cool a trapped 112Cd+ ion by directly Doppler-cooling a 114Cd+ ion in the same trap. This is the first demonstration of optically addressing a single trapped ion being sympathetically cooled by a different species ion. Notably, the experiment uses a single laser source, and does not require strong focusing. This paves the way toward reducing decoherence in an ion trap quantum computer based on Cd+ isotopes.

  14. The biophysics of renal sympathetic denervation using radiofrequency energy.

    Science.gov (United States)

    Patel, Hitesh C; Dhillon, Paramdeep S; Mahfoud, Felix; Lindsay, Alistair C; Hayward, Carl; Ernst, Sabine; Lyon, Alexander R; Rosen, Stuart D; di Mario, Carlo

    2014-05-01

    Renal sympathetic denervation is currently performed in the treatment of resistant hypertension by interventionists who otherwise do not typically use radiofrequency (RF) energy ablation in their clinical practice. Adequate RF lesion formation is dependent upon good electrode-tissue contact, power delivery, electrode-tissue interface temperature, target-tissue impedance and the size of the catheter's active electrode. There is significant interplay between these variables and hence an appreciation of the biophysical determinants of RF lesion formation is required to provide effective and safe clinical care to our patients. In this review article, we summarize the biophysics of RF ablation and explain why and how complications of renal sympathetic denervation may occur and discuss methods to minimise them.

  15. Morbidity in reflex sympathetic dystrophy

    Science.gov (United States)

    Murray, C.; Cohen, A.; Perkins, T.; Davidson, J.; Sills, J.

    2000-01-01

    Reflex sympathetic dystrophy (RSD), an unusual diagnosis in general paediatrics, is well recognised by paediatric rheumatologists. This study reports the presentation and the clinical course of 46 patients (35 female, age range 8-15.2) with RSD. The patients saw professionals from an average of 2.3 specialties (range 1-5). Twenty five (54%) had a history of trauma. Median time to diagnosis was 12 weeks (range 1-130). Many children had multiple investigations and treatments. Once diagnosis was made, treatment followed with physiotherapy and analgesics. Median time to recovery was seven weeks (range 1-140), with 27.5% relapsing. Nine children required assessment by the child and adolescent psychiatry team. This disease, though rare, has significant morbidity and it is therefore important to raise clinicians' awareness of RSD in childhood. Children with the condition may then be recognised and referred for appropriate management earlier, and spared unnecessary investigations and treatments which may exacerbate the condition.

 PMID:10685927

  16. Explosives malfunction from sympathetic detonation to shock desensitization

    Energy Technology Data Exchange (ETDEWEB)

    Katsabanis, P.D.; Yeung, C.; Fitz, G.; Heater, R. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Mining Engineering

    1994-12-31

    Explosives malfunction due to shock waves is a serious concern for successful blasting results. Malfunction can range from sympathetic detonation to desensitization and modification of firing times of conventional pyrotechnic detonators. Decked charges consisting of commercial emulsion explosives having a detonator and a primer were placed in 10cm diameter blastholes and their performance was recorded. Due to the limited length of the holes the events were mainly sympathetic detonations although desensitization was also recorded. Pressure measurements along the stemming column showed that shock waves produced by an explosive have a significant amplitude even at relatively large distances away from the detonating explosive. It was found that 2m away from a detonating charge the pressures in the stemming material were above 0.1 GPa indicating that there is potential for primers and detonators to malfunction. Parallel charges consisting of a commercial emulsion explosive with a diameter of 32mm were confined in 2mm thick steel tubes and initiation was attempted using detonators having a delay interval of 25ms. The charges were placed in sand and the velocity of detonation of the acceptor charge was recorded using a continuous resistance probe system. Carbon resistors were also placed in the same position as the acceptor charge to examine the dynamic pressures that were applied to the charge. Sympathetic detonation, complete desensitization, partial desensitization and properly sequenced detonations were observed as the distance between charges was increased from 76 mm to 305 mm. Delay detonators were also tested in a similar to the last configuration. Modification of firing times was observed at distances between 150 and 360 mm.

  17. Adolescent Physical Activity and Motivational Profiles While Keeping a Physical Activity Record

    Science.gov (United States)

    Fullmer, Matthew O.; Wilkinson, Carol; Prusak, Keven A.; Eggett, Dennis; Pennington, Todd

    2018-01-01

    Purpose: This study examined the relationship between adolescents (N = 124) from physical education classes keeping a daily online leisure-time physical activity (LTPA) record and feelings of competence toward LTPA, motivational profiles toward LTPA, and LTPA behaviors. Method: A repeated measures ANCOVA was used to examine the relationships…

  18. Sympathetic skin response in incomplete spinal cord injury with urinary incontinence

    Directory of Open Access Journals (Sweden)

    Reza Emad

    2013-01-01

    Full Text Available Objectives: Sympathetic skin response (SSR is a test for evaluation of the sympathetic sweat gland pathways, and it has been used to study the central sympathetic pathways in spinal cord injury (SCI. This study aimed to assess the autonomic pathways according to normal or abnormal SSR in urinary incontinence patients due to incomplete spinal cord injury. Materials and Methods: Suprapubic, palmar, and plantar SSR to the peripheral nerve electrical stimulation were recorded in 16 urinary incontinence patients with incomplete spinal cord injury at various neurological levels and in 30 healthy control subjects. Results: All the recordings of SSR from the incomplete SCI patients with urinary incontinence as compared with their counterparts in the control group showed significantly reduced amplitudes with more prominent reduction in the suprapubic area recording site (P value < 0.0004. SSR with significantly prolonged latencies were recorded from palm and plantar areas in response to suprapubic area and tibial N stimuli, respectively (P value < 0.02. In this study, a significantly higher stimulus intensity (P value < 0.01 was needed to elicit SSR in the cases compared with the control group. Conclusion: This study showed abnormal SSR in urinary incontinence patients due to incomplete SCI. In addition, for the first time we have described recording of abnormal SSR from the suprapubic area as another way to show bladder sympathetic system involvement.

  19. Assessing physical activity during youth sport: the Observational System for Recording Activity in Children: Youth Sports.

    Science.gov (United States)

    Cohen, Alysia; McDonald, Samantha; McIver, Kerry; Pate, Russell; Trost, Stewart

    2014-05-01

    The purpose of this study was to evaluate the validity and interrater reliability of the Observational System for Recording Activity in Children: Youth Sports (OSRAC:YS). Children (N = 29) participating in a parks and recreation soccer program were observed during regularly scheduled practices. Physical activity (PA) intensity and contextual factors were recorded by momentary time-sampling procedures (10-second observe, 20-second record). Two observers simultaneously observed and recorded children's PA intensity, practice context, social context, coach behavior, and coach proximity. Interrater reliability was based on agreement (Kappa) between the observer's coding for each category, and the Intraclass Correlation Coefficient (ICC) for percent of time spent in MVPA. Validity was assessed by calculating the correlation between OSRAC:YS estimated and objectively measured MVPA. Kappa statistics for each category demonstrated substantial to almost perfect interobserver agreement (Kappa = 0.67-0.93). The ICC for percent time in MVPA was 0.76 (95% C.I. = 0.49-0.90). A significant correlation (r = .73) was observed for MVPA recorded by observation and MVPA measured via accelerometry. The results indicate the OSRAC:YS is a reliable and valid tool for measuring children's PA and contextual factors during a youth soccer practice.

  20. Renal sympathetic denervation for treatment of patients with heart failure: summary of the available evidence.

    Science.gov (United States)

    Nammas, Wail; Koistinen, Juhani; Paana, Tuomas; Karjalainen, Pasi P

    2017-08-01

    Heart failure syndrome results from compensatory mechanisms that operate to restore - back to normal - the systemic perfusion pressure. Sympathetic overactivity plays a pivotal role in heart failure; norepinephrine contributes to maintenance of the systemic blood pressure and increasing preload. Cardiac norepinephrine spillover increases in patients with heart failure; norepinephrine exerts direct toxicity on cardiac myocytes resulting in a decrease of synthetic activity and/or viability. Importantly, cardiac norepinephrine spillover is a powerful predictor of mortality in patients with moderate to severe HF. This provided the rationale for trials that demonstrated survival benefit associated with the use of beta adrenergic blockers in heart failure with reduced ejection fraction. Nevertheless, the MOXCON trial demonstrated that rapid uptitration of moxonidine (inhibitor of central sympathetic outflow) in patients with heart failure was associated with excess mortality and morbidity, despite reduction of plasma norepinephrine. Interestingly, renal norepinephrine spillover was the only independent predictor of adverse outcome in patients with heart failure, in multivariable analysis. Recently, renal sympathetic denervation has emerged as a novel approach for control of blood pressure in patients with treatment-resistant hypertension. This article summarizes the available evidence for the effect of renal sympathetic denervation in the setting of heart failure. Key messages Experimental studies supported a beneficial effect of renal sympathetic denervation in heart failure with reduced ejection fraction. Clinical studies demonstrated improvement of symptoms, and left ventricular function. In heart failure and preserved ejection fraction, renal sympathetic denervation is associated with improvement of surrogate endpoints.

  1. Positive effects of electronic patient records on three clinical activities

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2008-01-01

     Purpose: To investigate the effects of a fully functional electronic patient record (EPR) system on clinicians' work during team conferences, ward rounds, and nursing handovers. Method: In collaboration with clinicians an EPR system was configured for a stroke unit and in trial use for five days...... the handover. Further, the status of the nursing plans for each patient was clearer for all nurses at the nursing handovers except the nurse team leader, who experienced less clarity about the status of the plans. Conclusion: The clinicians experienced positive effects of electronic records over paper records...... are not to be expected to be in operational use in Denmark until at least two years from now. The EPR system was evaluated with respect to its effects on clinicians' mental workload, overview, and need for exchanging information. Effects were measured by comparing the use of electronic records with the use of paper...

  2. Effect of 3-Day Bed Rest on the Basal Sympathetic Activity and Responsiveness of this System to Physiological Stimuli In Athletes and Sedentary Subjects

    Science.gov (United States)

    Smorawinski, Jerzy; Adrian, Jacek; Kaciuba-Uscilko, Hanna; Nazar, Krystyna; Greenleaf, John E.; Dalton, P. Bonnie (Technical Monitor)

    2002-01-01

    The aims of this study were: (1) to examine the effect of three days of bed rest (BR) on basal plasma epinephrine [E] and norepinephrine [NE] and the catecholamine responses to various physiological stimuli, and (2) to find out whether previous physical activity modifies effects of BR. In the first series, 29 young men (11 sedentary students, 8 endurance and 10 strength trained athletes) were submitted to oral glucose tolerance test in supine position and to active orthostatic test before and after 3 days of BR. Plasma [E] and [NE] were measured after overnight fast (basal condition), at 60, 120 and 180 min after glucose ingestion (70 a), and at the 8th min of unsupported standing. In the second series, other 22 subjects (12 sedentary students, 10 endurance and 10 strength trained athletes) were submitted to 2 min cold pressor test (CPT) and exercise. Plasma E and NE were determined in the supine position after overnight fast and at 60th and 120th s of hand cooling. Then, after breakfast followed by 2-3 hour sitting, the subjects performed cycle ergometer exercise with workload increasing until volitional exhaustion. Plasma [E] and [NE] were determined at the end of each load. Plasma catecholamines were determined made radioenzymatically. After BR, basal plasma [NE] was decreased in endurance and strength athletes (psedentary subjects. In neither group BR affected the basal [E]. Responses of both catecholamines to glucose load were diminished after BR in all three groups (pwork intensity after than before BR (p<0.05).

  3. Neural correlates of fear-induced sympathetic response associated with the peripheral temperature change rate.

    Science.gov (United States)

    Yoshihara, Kazufumi; Tanabe, Hiroki C; Kawamichi, Hiroaki; Koike, Takahiko; Yamazaki, Mika; Sudo, Nobuyuki; Sadato, Norihiro

    2016-07-01

    Activation of the sympathetic nervous system is essential for coping with environmental stressors such as fearful stimuli. Recent human imaging studies demonstrated that activity in some cortical regions, such as the anterior cingulate cortex (ACC) and anterior insula cortex (aIC), is related to sympathetic activity. However, little is known about the functional brain connectivity related to sympathetic response to fearful stimuli. The participants were 32 healthy, right-handed volunteers. Functional magnetic resonance imaging (fMRI) was used to examine brain activity when watching horror and control movies. Fingertip temperature was taken during the scanning as a measure of sympathetic response. The movies were watched a second time, and the degree of fear (9-point Likert-type scale) was evaluated every three seconds. The brain activity of the ACC, bilateral aIC, and bilateral anterior prefrontal cortex (aPFC) was correlated with the change rate of fingertip temperature, with or without fearful stimuli. Functional connectivity analysis revealed significantly greater positive functional connectivity between the amygdala and the ACC and between the amygdala and the aIC when watching the horror movie than when watching the control movie. Whole-brain psycho-physiological interaction (PPI) analysis revealed that the functional connectivity between the left amygdala and the ACC was modulated according to the fear rating. Our results indicate that the increased functional connectivity between the left amygdala and the ACC represents a sympathetic response to fearful stimuli. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Reflex sympathetic dystrophy syndrome and neuromediators.

    Science.gov (United States)

    Pham, Thao; Lafforgue, Pierre

    2003-02-01

    Concepts related to the pathophysiology of reflex sympathetic dystrophy syndrome (RSDS) are changing. Although sympathetic influences are still viewed as the most likely mechanism underlying the development and/or perpetuation of RSDS, these influences are no longer ascribed to an increase in sympathetic tone. Rather, the most likely mechanism may be increased sensitivity to catecholamines due to sympathetic denervation with an increase in the number and/or sensitivity of peripheral axonal adrenoceptors. Several other pathophysiological mechanisms have been suggested, including neurogenic inflammation with the release of neuropeptides by primary nociceptive afferents and sympathetic efferents. These neuromediators, particularly substance P, calcitonin gene-related peptide, and neuropeptide Y (NPY), may play a pivotal role in the genesis of pain in RSDS. They induce an inflammatory response (cutaneous erythema and edema) and lower the pain threshold. Neurogenic inflammation at the site of the lesion with neuromediator accumulation or depletion probably contributes to the pathophysiology of RSDS. However, no single neuromediator has been proved responsible, and other hypotheses continue to arouse interest.

  5. [Professional outcome of reflex sympathetic dystrophy].

    Science.gov (United States)

    Dauty, M; Renaud, P; Deniaud, C; Tortellier, L; Dubois, C

    2001-03-01

    In spite of physical medicine and rehabilitation care, post-traumatic reflex sympathetic dystrophy can be at the origin of articular deficiency, which decrease the capacity to return to work. The aim of this study is to know the professional future of patients who present post-traumatic reflex sympathetic dystrophy. Eighteen months prospective study, carried out from patients in age to work, hospitalized in physical medicine and rehabilitation unit for ostéo-articular traumatism complicated by reflex sympathetic dystrophy. Description of the population and comorbidity factors preventing professional resumption. Determination of the duration of medical certificate and the modalities of professional resumption. From 16 patients in age to work, only 12 were able to resume a full time profession with an average period of 10.5 months +/- 5. The importance of the, the distale articular location of reflex sympathetic dystrophy (wrist - hand, ankle - foot), the association with a comorbidity such as chronic alcoholism represent pejorative factors of working resumption. Organizations of workstation are often necessary in six cases over eight, if the job is not sedentary. In the most complicated cases, inaptitudes in the work are pronounced with demand of professional reclassifying. Post-traumatic reflex sympathetic dystrophy represents a real challenge for the rehabilitation team, to minimize deficiencies and to help the patient to become again a worker.

  6. Differential sympathetic outflow to adipose depots is required for visceral fat loss in response to calorie restriction

    OpenAIRE

    Sipe, L M; Yang, C; Ephrem, J; Garren, E; Hirsh, J; Deppmann, C D

    2017-01-01

    The sympathetic nervous system (SNS) regulates energy homeostasis in part by governing fatty acid liberation from adipose tissue. We first examined whether SNS activity toward discrete adipose depots changes in response to a weight loss diet in mice. We found that SNS activity toward each adipose depot is unique in timing, pattern of activation, and habituation with the most dramatic contrast between visceral and subcutaneous adipose depots. Sympathetic drive toward visceral epididymal adipos...

  7. Mechanisms involved in nicotinic acetylcholine receptor-induced neurotransmitter release from sympathetic nerve terminals in the mouse vas deferens.

    Directory of Open Access Journals (Sweden)

    Damian J Williams

    Full Text Available Prejunctional nicotinic acetylcholine receptors (nAChRs amplify postganglionic sympathetic neurotransmission, and there are indications that intraterminal Ca(2+ stores might be involved. However, the mechanisms by which nAChR activation stimulates neurotransmitter release at such junctions is unknown. Rapid local delivery (picospritzing of the nAChR agonist epibatidine was combined with intracellular sharp microelectrode recording to monitor spontaneous and field-stimulation-evoked neurotransmitter release from sympathetic nerve terminals in the mouse isolated vas deferens. Locally applied epibatidine (1 µM produced 'epibatidine-induced depolarisations' (EIDs that were similar in shape to spontaneous excitatory junction potentials (SEJPs and were abolished by nonselective nAChR antagonists and the purinergic desensitizing agonist α,β-methylene ATP. The amplitude distribution of EIDs was only slightly shifted towards lower amplitudes by the selective α7 nAChR antagonists α-bungarotoxin and methyllcaconitine, the voltage-gated Na(+ channel blocker tetrodotoxin or by blocking voltage-gated Ca(2+ channels with Cd(2+. Lowering the extracellular Ca(2+ concentration reduced the frequency of EIDs by 69%, but more surprisingly, the Ca(2+-induced Ca(2+ release blocker ryanodine greatly decreased the amplitude (by 41% and the frequency of EIDs by 36%. Ryanodine had no effect on electrically-evoked neurotransmitter release, paired-pulse facilitation, SEJP frequency, SEJP amplitude or SEJP amplitude distribution. These results show that activation of non-α7 nAChRs on sympathetic postganglionic nerve terminals induces high-amplitude junctional potentials that are argued to represent multipacketed neurotransmitter release synchronized by intraterminal Ca(2+-induced Ca(2+ release, triggered by Ca(2+ influx directly through the nAChR. This nAChR-induced neurotransmitter release can be targeted pharmacologically without affecting spontaneous or electrically

  8. The effects of baroreflex activation therapy on blood pressure and sympathetic function in patients with refractory hypertension: the rationale and design of the Nordic BAT study.

    Science.gov (United States)

    Gordin, Daniel; Fadl Elmula, Fadl Elmula M; Andersson, Bert; Gottsäter, Anders; Elf, Johan; Kahan, Thomas; Christensen, Kent Lodberg; Vikatmaa, Pirkka; Vikatmaa, Leena; Bastholm Olesen, Thomas; Groop, Per-Henrik; Olsen, Michael Hecht; Tikkanen, Ilkka

    2017-10-01

    To explore the effects of baroreflex activation therapy (BAT) on hypertension in patients with treatment resistant or refractory hypertension. This investigator-initiated randomized, double-blind, 1:1 parallel-design clinical trial will include 100 patients with refractory hypertension from 6 tertiary referral hypertension centers in the Nordic countries. A Barostim Neo System will be implanted and after 1 month patients will be randomized to either BAT for 16 months or continuous pharmacotherapy (BAT off) for 8 months followed by BAT for 8 months. A second randomization will take place after 16 months to BAT or BAT off for 3 months. Eligible patients have a daytime systolic ambulatory blood pressure (ABPM) of  ≥145 mm Hg, and/or a daytime diastolic ABPM of  ≥95 mm Hg after witnessed drug intake (including  ≥3 antihypertensive drugs, preferably including a diuretic). The primary end point is the reduction in 24-hour systolic ABPM by BAT at 8 months, as compared to pharmacotherapy. Secondary and tertiary endpoints are effects of BAT on home and office blood pressures, measures of indices of cardiac and vascular structure and function during follow-up, and safety. This academic initiative will increase the understanding of mechanisms and role of BAT in the refractory hypertension.

  9. An electronic device to record behavioural activity of bivalves.

    Science.gov (United States)

    Eapen, J T

    1997-06-01

    An electronic device to record the valvular movements of clams was fabricated using a Hall effect transducer. It was used to record the responses of Anadara granosa, an arcid clam harvested from coastal waters of Bombay, to a chemical toxicant (10 ppm CuSO4) after 96 hr exposure to naphthalene (5, 10 and 15 ppm). The clams exposed to naphthalene did not respond to the presence of a chemical toxicant (10 ppm CuSO4) while the control clams responded and closed their shells rapidly.

  10. Chewing-induced hypertension in afferent baroreflex failure: A sympathetic response?

    Science.gov (United States)

    Mora, Cristina Fuente; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto; Kaufmann, Horacio

    2016-01-01

    Familial dysautonomia (FD) is a rare genetic disease with extremely labile blood pressure due to baroreflex deafferentation. Patients have marked surges in sympathetic activity, frequently surrounding meals. We conducted an observational study to document the autonomic responses to eating in patients with FD, and to determine whether sympathetic activation was caused by chewing, swallowing or stomach distension. Blood pressure and RR intervals were measured continuously while chewing gum (n= 15), swallowing food (n=20) and distending the stomach with a gastrostomy feed (n=9). Responses were compared to those of normal controls (n=10) and of patients with autonomic failure (n=10) who have chronically impaired sympathetic outflow. In patients with FD, swallowing food was associated with a marked, but transient pressor response (p<0.0001) and additional signs of sympathetic activation including tachycardia, diaphoresis and flushing of the skin. Chewing gum evoked a similar increase in blood pressure that was higher in patients with FD than in controls (p=0.0001), but was absent in patients with autonomic failure. In patients with FD distending the stomach with a gastrostomy feed failed to elicit a pressor response. The results provide indirect evidence that chewing triggers sympathetic activation. The increase in blood pressure that is exaggerated in patients with FD due to blunted afferent baroreceptor signalling. The chewing pressor response may be useful as a counter-manoeuvre to raise blood pressure and prevent symptomatic orthostatic hypotension in patients with FD. PMID:26435473

  11. Muscarinic M1 receptors activate phosphoinositide turnover and Ca2+ mobilisation in rat sympathetic neurones, but this signalling pathway does not mediate M-current inhibition

    Science.gov (United States)

    del Río, Elena; Bevilacqua, Jorge A; Marsh, Stephen J; Halley, Pamela; Caulfield, Malcolm P

    1999-01-01

    The relationship between muscarinic receptor activation, phosphoinositide turnover, calcium mobilisation and M-current inhibition has been studied in rat superior cervical ganglion (SCG) neurones in primary culture. Phosphoinositide-specific phospholipase C (PLC) stimulation was measured by the accumulation of [3H]-cytidine monophosphate phosphatidate (CMP-PA) after incubation with [3H]-cytidine in the presence of Li+. The muscarinic agonist oxotremorine methiodide (oxo-M) stimulated PLC in a dose-dependent manner with an EC50 of approximately 3.5 μm. The concentration-response curve for oxo-M was shifted to the right by a factor of about 10 by pirenzepine (100 nm), suggesting a pKB (—log of the apparent dissociation constant) of 7.9 ± 0.4, while himbacine (1 μm) shifted the curve by a factor of about 13 (pKB∼7.1 ± 0.6). This indicates involvement of the M1 muscarinic receptor in this response. The accumulation of CMP-PA was localised by in situ autoradiography to SCG principal neurones, with no detectable signal in glial cells present in the primary cultures. The ability of oxo-M to release Ca2+ from inositol(1,4,5)trisphosphate (InsP3)-sensitive stores was determined by fura-2 microfluorimetry of SCG neurones voltage clamped in perforated patch mode. Oxo-M failed to evoke intracellular Ca2+ (Cai2+) mobilisation in SCG neurones voltage clamped at −60 mV, but produced a significant Cai2+ rise (67 ± 15 nm, n = 9) in cells voltage clamped at −25 mV. Thapsigargin (0.5–1 μm) caused a 70% inhibition of the oxo-M-induced Cai2+ increase, indicating its intracellular origin, while oxo-M-induced inhibition of M-current in the same cells was unaffected by thapsigargin. Our results do not support the involvement of InsP3-sensitive calcium mobilisation in M-current inhibition. PMID:10517804

  12. Bone scintigraphy in the reflex sympathetic dystrophy syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kozin, F.; Soin, J.S.; Ryan, L.M.; Carrera, G.F.; Wortmann, R.L.

    1981-02-01

    Sixty-four consecutive patients were studied for possible reflex sympathetic dystrophy syndrome (RSDS). They were divided into five groups, based upon specific clinical criteria, and the radiographic and scintigraphic findings in each group were examined. Osteoporosis was the most common radiographic abnormality. Scintigraphic abnormalities were noted in 60% of RSDS patients but in only 7% of the others. These findings included increased blood flow and enhanced periarticular radionuclide activity in the affected extremity. The scan may reflect an active, potentially reversible disorder of local blood flow in RSDS. Furthermore, the scintigraphic patterns may be useful in the diagnosis and in predicting which patients are likely to respond to systemic steroid therapy.

  13. Reflex sympathetic dystrophy: reflections from a clinician.

    Science.gov (United States)

    Small, Eric

    2007-05-01

    Reflex sympathetic dystrophy is defined as chronic musculoskeletal pain and autonomic dysfunction. It is a difficult diagnosis to make, and the adolescent often sees many specialists before arriving at the correct diagnosis. In this article I review reflex sympathetic dystrophy and reflect on the differential diagnosis, pertinent medical history, personal characteristics of patients with reflex sympathetic dystrophy, physical examination, and laboratory evaluation. Principles of management are considered, including physical therapy, pharmacology, psychological therapy, and alternative therapies. Accurate diagnosis and management are critical for not prolonging the adolescent's and the family's suffering. It is important to provide aggressive physical therapy, stress management, relaxation training, and close follow-up. It is also critical to avoid immobilization, surgery, or invasive procedures and unnecessary tests.

  14. Assessment of left ventricular ejection force and sympathetic skin response in normotensive and hypertensive subjects: A double-blind observational comparative case–control study

    Directory of Open Access Journals (Sweden)

    Tarun Saxena

    2016-09-01

    Conclusion: Stage 1 hypertension is a stage of increased sympathetic activity, leading to increased LVEF and hypertension (resetting of baroreceptors; stage 2 hypertension is a stage of normal sympathetic activity, increased LVEF, increased SV, and hypertension (possibly a stage of shift of renal equilibrium curve/renal output curve and blood pressure to a newer level.

  15. Identification of human sympathetic neurovascular control using multivariate wavelet decomposition analysis.

    Science.gov (United States)

    Saleem, Saqib; Teal, Paul D; Kleijn, W Bastiaan; Ainslie, Philip N; Tzeng, Yu-Chieh

    2016-09-01

    The dynamic regulation of cerebral blood flow (CBF) is thought to involve myogenic and chemoreflex mechanisms, but the extent to which the sympathetic nervous system also plays a role remains debated. Here we sought to identify the role of human sympathetic neurovascular control by examining cerebral pressure-flow relations using linear transfer function analysis and multivariate wavelet decomposition analysis that explicitly accounts for the confounding effects of dynamic end-tidal Pco2 (PetCO2 ) fluctuations. In 18 healthy participants randomly assigned to the α1-adrenergic blockade group (n = 9; oral Prazosin, 0.05 mg/kg) or the placebo group (n = 9), we recorded blood pressure, middle cerebral blood flow velocity, and breath-to-breath PetCO2 Analyses showed that the placebo administration did not alter wavelet phase synchronization index (PSI) values, whereas sympathetic blockade increased PSI for frequency components ≤0.03 Hz. Additionally, three-way interaction effects were found for PSI change scores, indicating that the treatment response varied as a function of frequency and whether PSI values were PetCO2 corrected. In contrast, sympathetic blockade did not affect any linear transfer function parameters. These data show that very-low-frequency CBF dynamics have a composite origin involving, not only nonlinear and nonstationary interactions between BP and PetCO2 , but also frequency-dependent interplay with the sympathetic nervous system. Copyright © 2016 the American Physiological Society.

  16. Anatomical variations of rami communicantes in the upper thoracic sympathetic trunk.

    Science.gov (United States)

    Cho, Hyun Min; Lee, Doo Yun; Sung, Sook Whan

    2005-02-01

    The aim of this study was to clearly delineate the anatomical variations of the communicating rami in the upper thoracic sympathetic nervous system and to help develop better surgical method for essential palmar hyperhidrosis. Anatomical dissections of the upper thoracic sympathetic chains with sympathetic ganglia and communicating rami have been carried out in 42 adult Korean cadavers (male 26, female 16). The rami communicantes were classified into three types (Normal: transverse or oblique rami connected to the intercostal nerve of the same level; AR: ascending rami connected to the higher level; DR: descending rami to the lower level) based on the anatomical relationship of the thoracic sympathetic ganglia to the intercostal nerves. Both sides of the upper thoracic sympathetic nervous system were compared in the same individual. The number of the communicating rami was recorded in 32 cadavers (64 sides). The distance from the rami communicantes to the sympathetic trunk was measured in 26 cadavers (52 sides). The incidence of AR (ascending rami) and DR (descending rami) arising from the second sympathetic ganglion was 53.6% (45/84), 46.4% (39/84). From the third thoracic sympathetic ganglion, the incidence of AR was 5.9% (5/84) and that of DR was 26.2% (22/84). And in the fourth thoracic sympathetic ganglion, the incidence of AR was 4.8% (4/84) and DR was 8.3% (7/84), respectively. When we compared anatomical structures of both sides among the 42 cadavers dissected, only 14.3% (6/42) had similar anatomy of the rami communicantes bilaterally. Among 32 cadavers (64 sides), the mean number of rami communicantes at the second thoracic sympathetic ganglion was 2.1/2.5 in the left and the right side. At the third and the fourth thoracic sympathetic ganglion, the mean number was 1.9/1.6 and 1.7/1.7 in each side. The mean distance from the thoracic sympathetic chain to the most distal communicating rami of the left and right side at the second intercostal nerve was 7

  17. Munchausen's syndrome simulating reflex sympathetic dystrophy.

    Science.gov (United States)

    Rodriguez-Moreno, J; Ruiz-Martin, J M; Mateo-Soria, L; Rozadilla, A; Roig-Escofet, D

    1990-01-01

    A 15 year old girl who had pain, oedema of her left hand, and fever of four months' duration is described. Marked demineralisation of her hand was shown by radiography, and increased articular uptake by technetium-99m bone scan. All these changes were indistinguishable from reflex sympathetic dystrophy. After two admissions to hospital and multiple explorations we discovered that she had induced her symptoms herself and a diagnosis of Munchausen's syndrome was made. As far as we know this presentation has not been previously reported and might help to explain the physiopathology of some signs of reflex sympathetic dystrophy. Images PMID:2270960

  18. Sympathetic stimulation alters left ventricular relaxation and chamber size.

    Science.gov (United States)

    Burwash, I G; Morgan, D E; Koilpillai, C J; Blackmore, G L; Johnstone, D E; Armour, J A

    1993-01-01

    Alterations in left ventricular (LV) contractility, relaxation, and chamber dimensions induced by efferent sympathetic nerve stimulation were investigated in nine anesthetized open-chest dogs in sinus rhythm. Supramaximal stimulation of acutely decentralized left stellate ganglia augmented heart rate, LV systolic pressure, and rate of LV pressure rise (maximum +dP/dt, 1,809 +/- 191 to 6,304 +/- 725 mmHg/s) and fall (maximum -dP/dt, -2,392 +/- 230 to -4,458 +/- 482 mmHg/s). It also reduced the time constant of isovolumic relaxation, tau (36.5 +/- 4.8 to 14.9 +/- 1.1 ms). Simultaneous two-dimensional echocardiography recorded reductions in end-diastolic and end-systolic LV cross-sectional chamber areas (23 and 31%, respectively), an increase in area ejection fraction (32%), and increases in end-diastolic and end-systolic wall thicknesses (14 and 13%, respectively). End-systolic and end-diastolic wall stresses were unchanged by stellate ganglion stimulation (98 +/- 12 to 95 +/- 9 dyn x 10(3)/cm2; 6.4 +/- 2.4 to 2.4 +/- 0.3 dyn x 10(3)/cm2, respectively). Atrial pacing to similar heart rates did not alter monitored indexes of contractility. Dobutamine and isoproterenol induced changes similar to those resulting from sympathetic neuronal stimulation. These data indicate that when the efferent sympathetic nervous system increases left ventricular contractility and relaxation, concomitant reductions in systolic and diastolic dimensions of that chamber occur that are associated with increasing wall thickness such that LV wall stress changes are minimized.

  19. Change in sympathetic nerve firing pattern associated with dietary weight loss in the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Elisabeth Annie Lambert

    2011-08-01

    Full Text Available Sympathetic activation in subjects with the metabolic syndrome (MS plays a role in the pathogenesis of cardiovascular disease development. Diet-induced weight loss decreases sympathetic outflow. However the mechanisms that account for sympathetic inhibition are not known. We sought to provide a detailed description of the sympathetic response to diet by analyzing the firing behavior of single-unit sympathetic nerve fibres. Fourteen subjects (57±2 years, 9 men, 5 females fulfilling ATP III criteria for the MS underwent a 3-month low calorie diet. Metabolic profile, hemodynamic parameters and multi-unit and single unit muscle sympathetic nerve activity (MSNA, microneurography were assessed prior to and at the end of the diet. Patients’ weight dropped from 96±4 to 88±3 kg (P<0.001. This was associated with a decrease in systolic and diastolic blood pressure (-12 ±3 and -5±2 mmHg, P<0.05, and in heart rate (-7±2 bpm, P<0.01 and an improvement in all metabolic parameters (fasting glucose: -0.302.1±0.118 mmol/l, total cholesterol: -0.564±0.164 mmol/l, triglycerides: -0.414±0.137 mmol/l, P<0.05. Multi-unit MSNA decreased from 68±4 to 59±5 bursts per 100 heartbeats (P<0.05. Single-unit MSNA indicated that the firing rate of individual vasoconstrictor fibres decreased from 59±10 to 32±4 spikes per 100 heart beats (P<0.05. The probability of firing decreased from 34±5 to 23±3 % of heartbeats (P<0.05, and the incidence of multiple firing decreased from 14±4 to 6±1 % of heartbeats (P<0.05. Cardiac and sympathetic baroreflex function were significantly improved (cardiac slope: 6.57±0.69 to 9.57±1.20 msec.mmHg-1; sympathetic slope: -3.86±0.34 to -5.05±0.47 bursts per 100 heartbeats.mmHg-1 P<0.05 for both. Hypocaloric diet decreased sympathetic activity and improved hemodynamic and metabolic parameters. The sympathoinhibition associated with weight loss involves marked changes, not only in the rate but also in the firing pattern of

  20. Coding the Complexity of Activity in Video Recordings

    DEFF Research Database (Denmark)

    Harter, Christopher Daniel; Otrel-Cass, Kathrin

    2017-01-01

    scheme, based on the theoretical principles of activity theory, was constructed in a video analysis software program, as a tool for coding and analyzing video data, without being too descriptive or prescriptive and in a variety of research fields. As of now, the coding scheme is a prototype developed......This paper presents a theoretical approach to coding and analyzing video data on human interaction and activity, using principles found in cultural historical activity theory. The systematic classification or coding of information contained in video data on activity can be arduous and time...... consuming; however, it is one of the ways to make sense of complex information, which in turn can add value to the process of exploring selected themes. By reviewing earlier attempts at using Activity Theory as a tool for guiding the examination of human activity in human–computer interaction by Susanne...

  1. A Salicylate Sympathetic Ink from Consumer Chemicals

    Science.gov (United States)

    Journal of Chemical Education, 2005

    2005-01-01

    A new sympathetic ink that produces a violet color upon development was developed to develop chemical demonstrations using consumer chemicals. The demonstration was to have a simple, relatively safe reagent system that could be used to make a brightly colored, highly visible "magic sign" for use in science outreach programs.

  2. TARGETED STELLATE DECENTRALIZATION: IMPLICATIONS FOR SYMPATHETIC CONTROL OF VENTRICULAR ELECTROPHYSIOLOGY

    Science.gov (United States)

    Buckley, Una; Yamakawa, Kentaro; Takamiya, Tatsuo; Armour, J. Andrew; Shivkumar, Kalyanam; Ardell, Jeffrey L.

    2015-01-01

    Background Selective, bilateral cervicothoracic sympathectomy has proven to be effective for managing ventricular arrhythmias in the setting of structural heart disease. The procedure currently employed removes the caudal portions of both stellate ganglia, along with thoracic chain ganglia down to T4 ganglia. Objective To define the relative contributions of T1-T2 and the T3-T4 paravertebral ganglia in modulating ventricular electrical function. Methods In anesthetized vagotomised porcine subjects (n=8), the heart was exposed via sternotomy along with right and left paravertebral sympathetic ganglia to the T4 level. A 56-electrode epicardial sock was placed over both ventricles to assess epicardial activation recovery intervals (ARI) in response to individually stimulating right and left stellate vs T3 paravertebral ganglia. Responses to T3 stimuli were repeated following surgical removal of the caudal portions of stellate ganglia and T2 bilaterally. Results In intact preparations, stellate ganglion vs T3 stimuli (4Hz, 4ms duration) were titrated to produce equivalent decreases in global ventricular ARIs (right-side 85±6 vs 55±10 ms; left-side 24±3 vs 17±7 ms). Threshold of stimulus intensity applied to T3 ganglia to achieve threshold was 3 times that of T1 threshold. ARIs in unstimulated states were unaffected by bilateral stellate-T2 ganglion removal. Following acute decentralization, T3 stimulation failed to change ARIs. Conclusion Preganglionic sympathetic efferents arising from the T1-T4 spinal cord that project to the heart transit through stellate ganglia via the paravertebral chain. T1-T2 surgical excision is thus sufficient to functionally interrupt central control of peripheral sympathetic efferent activity. PMID:26282244

  3. Intermedin in the paraventricular nucleus attenuates cardiac sympathetic afferent reflex in chronic heart failure rats.

    Directory of Open Access Journals (Sweden)

    Xian-Bing Gan

    Full Text Available BACKGROUND AND AIM: Intermedin (IMD is a member of calcitonin/calcitonin gene-related peptide (CGRP family together with adrenomedullin (AM and amylin. It has a wide distribution in the central nervous system (CNS especially in hypothalamic paraventricular nucleus (PVN. Cardiac sympathetic afferent reflex (CSAR is enhanced in chronic heart failure (CHF rats. The aim of this study is to determine the effect of IMD in the PVN on CSAR and its related mechanisms in CHF rats. METHODOLOGY/PRINCIPAL FINDINGS: Rats were subjected to left descending coronary artery ligation to induce CHF or sham-operation (Sham. Renal sympathetic nerve activity (RSNA, mean arterial pressure (MAP and heart rate (HR were recorded. CSAR was evaluated by the RSNA and MAP responses to epicardial application of capsaicin. Acute experiments were carried out 8 weeks after coronary ligation or sham surgery under anesthesia. IMD and angiotensin II (Ang II levels in the PVN were up-regulated in CHF rats. Bilateral PVN microinjection of IMD caused greater decreases in CSAR and the baseline RSNA and MAP in CHF rats than those in Sham rats. The decrease of CSAR caused by IMD was prevented by pretreatment with AM receptor antagonist AM22-52, but not CGRP receptor antagonist CGRP8-37. Ang II in the PVN significantly enhanced CSAR and superoxide anions level, which was inhibited by PVN pretreatment with IMD or tempol (a superoxide anions scavenger in Sham and CHF rats. CONCLUSION: IMD in the PVN inhibits CSAR via AM receptor, and attenuates the effects of Ang II on CSAR and superoxide anions level in CHF rats. PVN superoxide anions involve in the effect of IMD on attenuating Ang II-induced CSAR response.

  4. Renal denervation in male rats with heart failure improves ventricular sympathetic nerve innervation and function.

    Science.gov (United States)

    Pinkham, Maximilian I; Loftus, Michael T; Amirapu, Satya; Guild, Sarah-Jane; Quill, Gina; Woodward, William R; Habecker, Beth A; Barrett, Carolyn J

    2017-03-01

    Heart failure is characterized by the loss of sympathetic innervation to the ventricles, contributing to impaired cardiac function and arrhythmogenesis. We hypothesized that renal denervation (RDx) would reverse this loss. Male Wistar rats underwent myocardial infarction (MI) or sham surgery and progressed into heart failure for 4 wk before receiving bilateral RDx or sham RDx. After additional 3 wk, left ventricular (LV) function was assessed, and ventricular sympathetic nerve fiber density was determined via histology. Post-MI heart failure rats displayed significant reductions in ventricular sympathetic innervation and tissue norepinephrine content (nerve fiber density in the LV of MI+sham RDx hearts was 0.31 ± 0.05% vs. 1.00 ± 0.10% in sham MI+sham RDx group, P renal nerve activity and cardiac sympathetic nerve innervation in heart failure. Our findings show denervating the renal nerves improves cardiac sympathetic innervation and function in the post-MI failing heart. Copyright © 2017 the American Physiological Society.

  5. Alterations of sympathetic nerve fibers in avascular necrosis of femoral head.

    Science.gov (United States)

    Li, Deqiang; Liu, Peilai; Zhang, Yuankai; Li, Ming

    2015-01-01

    Avascular necrosis of the femoral head (ANFH) was mainly due to alterations of bone vascularity. And noradrenaline (NA), as the neurotransmitter of the sympathetic nervous system (SNS), leads to the vasoconstriction by activating its α-Receptor. This study was to explore the nerve fiber density of the femoral head in the rabbit model of ANFH. Twenty New Zealand white rabbits were used in this study. The rabbit model of ANFH was established by the injection of methylprednisolone acetate. The nerve fiber density and distribution in the femoral head was determined using an Olympus BH2 microscope. Significant fewer sympathetic nerve fibers was found in the ANFH intertrochanteric bone samples (P = 0.036) with osteonecrosis. The number of sympathetic nerve fibers was compared between the two groups. And less sympathetic nerve fibers were found in later stage ANFH samples in comparison with those of early stages. ANFH might be preceded by an inflammatory reaction, and an inflammatory response might lead to arthritic changes in tissue samples, which in turn reduces the number of sympathetic nerve fibers.

  6. Role of myocardial hypertrophy in trophic stimulation of indices of sympathetic cardiac innervation.

    Science.gov (United States)

    Lindpaintner, K; Lund, D D; Schmid, P G

    1987-01-01

    Indices of cardiac sympathetic innervation have commonly been found depressed in the failing, hypertrophied heart. In contrast, we have recently demonstrated that hemodynamically compensated, very gradually developing right ventricular hypertrophy is associated with an increase in sympathetic nervous markers. The present experiments were performed to corroborate these findings in a model of acutely induced right ventricular hypertrophy, and to further characterize changes in markers of autonomic innervation associated with cardiac hypertrophy. Male guinea pigs underwent either pulmonary artery banding (P) with an acutely constricting ligature, or bilateral stellate ganglionectomy (S), or both (PS). Appropriate sham procedures were performed in animals subjected to only one intervention; controls (C) underwent sham-S and sham-P. Groups of animals were sacrificed at 10 and 20 days after surgery. Cardiac tissues were weighed and subsequently analyzed for activities of tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH), two enzymes catalyzing the biosynthesis of catecholamines (CAs), and of choline acetyltransferase (CAT), a marker of parasympathetic activity, as well as for norepinephrine (NE). S resulted in profound depletions of cardiac NE of 88-92% and in significant decreases in the activities of DBH and TH. Marked right ventricular hypertrophy developed rapidly following P, and was not modified by S. Similar to our previous results, acute right ventricular hypertrophy was associated with moderate increases (10-20%) of sympathetic markers; following S, these increases (of presumably residual sympathetic innervation) were greatly enhanced, amounting to 171% and 105% for NE at 10 and 20 days, respectively. In contrast, sympathetic markers in the left ventricle of stellatectomized animals were not affected by P. Activity of CAT remained unaltered by the experimental interventions. Our experiments indicate that increases in markers of sympathetic

  7. Underwater sympathetic detonation of pellet explosive

    Science.gov (United States)

    Kubota, Shiro; Saburi, Tei; Nagayama, Kunihito

    2017-06-01

    The underwater sympathetic detonation of pellet explosives was taken by high-speed photography. The diameter and the thickness of the pellet were 20 and 10 mm, respectively. The experimental system consists of the precise electric detonator, two grams of composition C4 booster and three pellets, and these were set in water tank. High-speed video camera, HPV-X made by Shimadzu was used with 10 Mfs. The underwater explosions of the precise electric detonator, the C4 booster and a pellet were also taken by high-speed photography to estimate the propagation processes of the underwater shock waves. Numerical simulation of the underwater sympathetic detonation of the pellet explosives was also carried out and compared with experiment.

  8. Reflex sympathetic dystrophy syndrome in a child.

    Science.gov (United States)

    Badri, Talel; Ben Jennet, Salima; Fenniche, Samy; Benmously, Rym; Mokhtar, Inçaf; Hammami, Hatem

    2011-06-01

    Reflex sympathetic dystrophy syndrome (RSDS) is a painful condition that usually follows regional trauma. We report the case of a 13-year-old girl that was seen for a painful swelling of the right hand associated with palmar hyperhidrosis, which occurred after a trauma to the hand. Bone scan images showed early tissue abnormality, which was more significant on the right hand and wrist, as well as moderate bone uptake on the right side. Nonsteroidal anti-inflammatory drugs and alternating hot and cold baths led to a marked improvement. RSDS occurs following trauma or subsequent to various diseases or drug intake. This syndrome is related to impaired tissue microvasculature under the influence of abnormal sympathetic reflex hyperactivity. Bone scan is the diagnostic procedure of choice in RSDS, but it may be normal. Physiotherapy should be preferred in pediatric cases.

  9. Sympathetic blocks for visceral cancer pain management

    DEFF Research Database (Denmark)

    Mercadante, Sebastiano; Klepstad, Pal; Kurita, Geana Paula

    2015-01-01

    The neurolytic blocks of sympathetic pathways, including celiac plexus block (CPB) and superior hypogastric plexus block (SHPB) , have been used for years. The aim of this review was to assess the evidence to support the performance of sympathetic blocks in cancer patients with abdominal visceral...... pain. Only comparison studies were included. All data from the eligible trials were analyzed using the GRADE system. Twenty-seven controlled studies were considered. CPB, regardless of the technique used, improved analgesia and/or decrease opioid consumption, and decreased opioid-induced adverse...... effects in comparison with a conventional analgesic treatment. In one study patients treated with superior hypogastric plexus block (SHPB) had a decrease in pain intensity and a less morphine consumption, while no statistical differences in adverse effects were found. The quality of these studies...

  10. Divergent muscle sympathetic responses to dynamic leg exercise in heart failure and age-matched healthy subjects.

    Science.gov (United States)

    Notarius, Catherine F; Millar, Philip J; Murai, Hisayoshi; Morris, Beverley L; Marzolini, Susan; Oh, Paul; Floras, John S

    2015-02-01

    People with diminished ventricular contraction who develop heart failure have higher sympathetic nerve firing rates at rest compared with healthy individuals of a similar age and this is associated with less exercise capacity. During handgrip exercise, sympathetic nerve activity to muscle is higher in patients with heart failure but the response to leg exercise is unknown because its recording requires stillness. We measured sympathetic activity from one leg while the other leg cycled at a moderate level and observed a decrease in nerve firing rate in healthy subjects but an increase in subjects with heart failure. Because these nerves release noradrenaline, which can restrict muscle blood flow, this observation helps explain the limited exercise capacity of patients with heart failure. Lower nerve traffic during exercise was associated with greater peak oxygen uptake, suggesting that if exercise training attenuated sympathetic outflow functional capacity in heart failure would improve. The reflex fibular muscle sympathetic nerve (MSNA) response to dynamic handgrip exercise is elicited at a lower threshold in heart failure with reduced ejection fraction (HFrEF). The present aim was to test the hypothesis that the contralateral MSNA response to mild to moderate dynamic one-legged exercise is augmented in HFrEF relative to age- and sex-matched controls. Heart rate (HR), blood pressure and MSNA were recorded in 16 patients with HFrEF (left ventricular ejection fraction = 31 ± 2%; age 62 ± 3 years, mean ± SE) and 13 healthy control subjects (56 ± 2 years) before and during 2 min of upright one-legged unloaded cycling followed by 2 min at 50% of peak oxygen uptake (V̇O2,peak). Resting HR and blood pressure were similar between groups whereas MSNA burst frequency was higher (50.0 ± 2.0 vs. 42.3 ± 2.7 bursts min(-1), P = 0.03) and V̇O2,peak lower (18.0 ± 2.0 vs. 32.6 ± 2.8 ml kg(-1) min(-1), P Exercise increased HR (P exercise in the healthy controls but

  11. Low plasma volume coincides with sympathetic hyperactivity and reduced baroreflex sensitivity in formerly preeclamptic patients.

    NARCIS (Netherlands)

    Courtar, D.A.; Spaanderman, M.E.A.; Aardenburg, R.; Janssen, B.J.; Peeters, L.L.

    2006-01-01

    BACKGROUND: Preeclampsia is associated with enhanced sympathetic activity as well as subnormal plasma volume. Meanwhile, in over 50% of these complicated pregnancies, the subnormal plasma volume has been found to persist for a prolonged period after pregnancy. The objective of this study is to test

  12. The Suprachiasmatic nucleus balances sympathetic and parasympathetic output to peripheral organs through separate preautonomic neurons

    NARCIS (Netherlands)

    Buijs, Ruud M.; la Fleur, Susanne E.; Wortel, Joke; van Heyningen, Caroline; Zuiddam, Laura; Mettenleiter, Thomas C.; Kalsbeek, Andries; Nagai, Katsuya; Niijima, Akira

    2003-01-01

    Opposing parasympathetic and sympathetic signals determine the autonomic output of the brain to the body and the change in balance over the sleep-wake cycle. The suprachiasmatic nucleus (SCN) organizes the activity/inactivity cycle and the behaviors that go along with it, but it is unclear how the

  13. High dose ascorbic acid does not reverse central sympathetic overactivity in chronic heart failure

    NARCIS (Netherlands)

    Gomes, M.E.R.; El Messaoudi, S.; Lenders, J.W.M.; Bellersen, L.; Verheugt, F.W.A.; Smits, P.; Tack, C.J.J.

    2011-01-01

    WHAT IS KNOWN AND OBJECTIVE: The increased central sympathetic activity typically associated with chronic heart failure (CHF) is probably mediated by formation of reactive oxygen species (ROS) in the brain. Our objective was to undertake a trial to test our hypothesis that administration of the

  14. Sympathetic responses during saline infusion into the veins of an occluded limb.

    Science.gov (United States)

    Cui, Jian; McQuillan, Patrick; Moradkhan, Raman; Pagana, Charles; Sinoway, Lawrence I

    2009-07-15

    Animal studies have shown that the increased intravenous pressure stimulates the group III and IV muscle afferent fibres, and in turn induce cardiovascular responses. However, this pathway of autonomic regulation has not been examined in humans. The aim of this study was to examine the hypothesis that infusion of saline into the venous circulation of an arterially occluded vascular bed evokes sympathetic activation in healthy individuals. Blood pressure, heart rate, and muscle sympathetic nerve activity (MSNA) responses were assessed in 19 young healthy subjects during local infusion of 40 ml saline into a forearm vein in the circulatory arrested condition. From baseline (11.8 +/- 1.2 bursts min(-1)), MSNA increased significantly during the saline infusion (22.5 +/- 2.6 bursts min(-1), P Blood pressure also increased significantly during the saline infusion. Three control trials were performed during separate visits. The results from the control trial show that the observed MSNA and blood pressure responses were not due to muscle ischaemia. The present data show that saline infusion into the venous circulation of an arterially occluded vascular bed induces sympathetic activation and an increase in blood pressure. We speculate that the infusion under such conditions stimulates the afferent endings near the vessels, and evokes the sympathetic activation.

  15. Pathophysiology of Resistant Hypertension: The Role of Sympathetic Nervous System

    Directory of Open Access Journals (Sweden)

    Costas Tsioufis

    2011-01-01

    Full Text Available Resistant hypertension (RH is a powerful risk factor for cardiovascular morbidity and mortality. Among the characteristics of patients with RH, obesity, obstructive sleep apnea, and aldosterone excess are covering a great area of the mosaic of RH phenotype. Increased sympathetic nervous system (SNS activity is present in all these underlying conditions, supporting its crucial role in the pathophysiology of antihypertensive treatment resistance. Current clinical and experimental knowledge points towards an impact of several factors on SNS activation, namely, insulin resistance, adipokines, endothelial dysfunction, cyclic intermittent hypoxaemia, aldosterone effects on central nervous system, chemoreceptors, and baroreceptors dysregulation. The further investigation and understanding of the mechanisms leading to SNS activation could reveal novel therapeutic targets and expand our treatment options in the challenging management of RH.

  16. 77 FR 55221 - Agency Information Collection Activities: Report of Medical Examination and Vaccination Record...

    Science.gov (United States)

    2012-09-07

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Citizenship and Immigration Services [OMB Control Number 1615-0033] Agency Information Collection Activities: Report of Medical Examination and Vaccination Record... Approved Collection. (2) Title of the Form/Collection: Report of Medical Examination and Vaccination Record...

  17. 75 FR 13293 - Agency Information Collection Activities: Arrival and Departure Record

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    2010-03-19

    ..., Carriers, Government Agencies, and the Travel and Tourism Industry I-94 (Arrival and Departure Record... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Arrival and Departure Record AGENCY: U.S. Customs and Border Protection, Department of Homeland...

  18. 78 FR 73237 - Reports, Forms and Record Keeping Requirements Agency Information Collection Activity Under OMB...

    Science.gov (United States)

    2013-12-05

    ...-0088] Reports, Forms and Record Keeping Requirements Agency Information Collection Activity Under OMB... entities over which the agency exercises regulatory authority. Recent trends lead the agency to estimate.... Requesters are not required to keep copies of any records or reports [[Page 73238

  19. [Role of renal sympathetic nerve and oxidative stress in foot shock-induced hypertension in rats].

    Science.gov (United States)

    Jiang, Ren-Di; Zhang, Zhe; Xu, Jian-Bing; Dong, Tao; Zhang, Guo-Xing

    2015-06-25

    The present study was aimed to investigate the roles of renal sympathetic nerve and oxidative stress in the development of foot shock-induced hypertension. Ninety rats were divided into 6 groups (the number of each group was 15): control group, foot shock group, denervation of renal sympathetic nerve group, denervation of renal sympathetic nerve + foot shock group, Tempol treatment + foot shock group, denervation of renal sympathetic nerve + Tempol treatment + foot shock group. Rats were received electrical foot shock for 14 days (2-4 mA, 75 V, shocks of 50-100 ms every 30 s, for 4 h each session through an electrified grid floor every day). Renal sympathetic ablation was used to remove bilateral renal sympathetic nerve in rats (rats were allowed to recover for one week before the beginning of the foot shock procedure). The antioxidant Tempol was injected intraperitoneally at 1 h before foot shock. Systolic blood pressure was measured at 1 h after foot shock on day 0, 3, 7, 10 and 14. Contents of thiobarbituric acid reactive substance (TBARS), renin, angiotensin II (AngII) and glutathione peroxidase (GSH-Px) in plasma were measured by ELISA after 14-day foot shock. The results showed that systolic blood pressure of foot shock group was significantly increased (P blood pressure induced by foot shock. Levels of TBARS, renin and AngII in plasma were increased significantly in foot shock group compared with that of control group (P oxidative stress and directly or indirectly activate renin-angiotensin-aldosterone system, so the foot shock-induced high blood pressure may be maintained and hypertension may therefore be produced.

  20. Development and Testing of the Observational System for Recording Physical Activity in Children: Elementary School

    Science.gov (United States)

    McIver, Kerry L.; Brown, William H.; Pfeiffer, Karin A.; Dowda, Marsha; Pate, Russell R.

    2016-01-01

    Purpose: This study describes the development and pilot testing of the Observational System for Recording Physical Activity-Elementary School (OSRAC-E) Version. Method: This system was developed to observe and document the levels and types of physical activity and physical and social contexts of physical activity in elementary school students…

  1. Comparing one-year recall and daily household records of livelihood activities

    DEFF Research Database (Denmark)

    Larsen, Helle Overgaard; Treue, Thorsten; Ngaga, Yonika

    2014-01-01

    activities. In this study we examine discrepancies between activities and associated incomes (cash and subsistence) reported by sample households through interviews conducted at the end of a one-year recall period and based on daily records of livelihood activities made by the same households throughout...

  2. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Active Fires Environmental Data Record (EDR) from IDPS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational environmental data record (EDR) that contains pinpoint locations of active fires (AF) as identified by an algorithm...

  3. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Active Fires Environmental Data Record (EDR) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) that contains pinpoint locations of active fires (AF) as identified by an algorithm...

  4. 77 FR 59249 - Agency Information Collection (Access to Financial Records) Activities Under OMB Review

    Science.gov (United States)

    2012-09-26

    ... . Please refer to ``OMB Control No. 2900-0739.'' SUPPLEMENTARY INFORMATION: Title: Access to Financial... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-0739] Agency Information Collection (Access to Financial Records) Activities Under OMB Review AGENCY: Veterans Benefits Administration...

  5. 77 FR 42556 - Proposed Information Collection (Access to Financial Records) Activity: Comment Request

    Science.gov (United States)

    2012-07-19

    ... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-0739] Proposed Information Collection (Access to Financial Records) Activity: Comment Request AGENCY: Veterans Benefits Administration, Department... of certain information by the agency. Under the Paperwork Reduction Act (PRA) of 1995, Federal...

  6. Sympathetic-induced changes in discharge rate and spike-triggered average twitch torque of low-threshold motor units in humans.

    Science.gov (United States)

    Roatta, Silvestro; Arendt-Nielsen, Lars; Farina, Dario

    2008-11-15

    Animal and in vitro studies have shown that the sympathetic nervous system modulates the contractility of skeletal muscle fibres, which may require adjustments in the motor drive to the muscle in voluntary contractions. In this study, these mechanisms were investigated in the tibialis anterior muscle of humans during sympathetic activation induced by the cold pressor test (CPT; left hand immersed in water at 4 degrees C). In the first experiment, 11 healthy men performed 20 s isometric contractions at 10% of the maximal torque, before, during and after the CPT. In the second experiment, 12 healthy men activated a target motor unit at the minimum stable discharge rate for 5 min in the same conditions as in experiment 1. Intramuscular electromyographic (EMG) signals and torque were recorded and used to assess the motor unit discharge characteristics (experiment 1) and spike-triggered average twitch torque (experiment 2). CPT increased the diastolic blood pressure and heart rate by (mean +/- S.D.) 18 +/- 9 mmHg and 4.7 +/- 6.5 beats min(-1) (P < 0.01), respectively. In experiment 1, motor unit discharge rate increased from 10.4 +/- 1.0 pulses s(-1) before to 11.1 +/- 1.4 pulses s(-1) (P < 0.05) during the CPT. In experiment 2, the twitch half-relaxation time decreased by 15.8 +/- 9.3% (P < 0.05) during the CPT with respect to baseline. These results provide the first evidence of an adrenergic modulation of contractility of muscle fibres in individual motor units in humans, under physiological sympathetic activation.

  7. [An evaluation of the kinin and sympathetic-adrenal systems and prostanoids in rheumatism with a heart rhythm disorder].

    Science.gov (United States)

    Vasilenko, E P; Kudintseva, T Z; Vizir, V A

    1991-09-01

    A comparative study is presented of some components of the kinin, sympathetic-adrenal system and plasma prostacyclin in 296 patients with active rheumatism of different activity grades and disorders of the cardiac rhythm. Data were obtained on the activation of the sympathetic-adrenal and kinin system in rheumocarditis with disorders of the cardiac rhythm. A relationship was established between the components of these systems. The content of prostacyclin in patients with rheumatism in the active phase was reduced. The effect of the mentioned biologically active substances on the development of arrhythmias is discussed.

  8. Reactive oxygen species are involved in BMP-induced dendritic growth in cultured rat sympathetic neurons.

    Science.gov (United States)

    Chandrasekaran, Vidya; Lea, Charlotte; Sosa, Jose Carlo; Higgins, Dennis; Lein, Pamela J

    2015-07-01

    Previous studies have shown that bone morphogenetic proteins (BMPs) promote dendritic growth in sympathetic neurons; however, the downstream signaling molecules that mediate the dendrite promoting activity of BMPs are not well characterized. Here we test the hypothesis that reactive oxygen species (ROS)-mediated signaling links BMP receptor activation to dendritic growth. In cultured rat sympathetic neurons, exposure to any of the three mechanistically distinct antioxidants, diphenylene iodinium (DPI), nordihydroguaiaretic acid (NGA) or desferroxamine (DFO), blocked de novo BMP-induced dendritic growth. Addition of DPI to cultures previously induced with BMP to extend dendrites caused dendritic retraction while DFO and NGA prevented further growth of dendrites. The inhibition of the dendrite promoting activity of BMPs by antioxidants was concentration-dependent and occurred without altering axonal growth or neuronal cell survival. Antioxidant treatment did not block BMP activation of SMAD 1,5 as determined by nuclear localization of these SMADs. While BMP treatment did not cause a detectable increase in intracellular ROS in cultured sympathetic neurons as assessed using fluorescent indicator dyes, BMP treatment increased the oxygen consumption rate in cultured sympathetic neurons as determined using the Seahorse XF24 Analyzer, suggesting increased mitochondrial activity. In addition, BMPs upregulated expression of NADPH oxidase 2 (NOX2) and either pharmacological inhibition or siRNA knockdown of NOX2 significantly decreased BMP-7 induced dendritic growth. Collectively, these data support the hypothesis that ROS are involved in the downstream signaling events that mediate BMP7-induced dendritic growth in sympathetic neurons, and suggest that ROS-mediated signaling positively modulates dendritic complexity in peripheral neurons. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Effects of sympathetic stimulation on the rhythmical jaw movements produced by electrical stimulation of the cortical masticatory areas of rabbits.

    Science.gov (United States)

    Roatta, S; Windhorst, U; Djupsjöbacka, M; Lytvynenko, S; Passatore, M

    2005-03-01

    The somatomotor and sympathetic nervous systems are intimately linked. One example is the influence of peripheral sympathetic fibers on the discharge characteristics of muscle spindles. Since muscle spindles play important roles in various motor behaviors, including rhythmic movements, the working hypothesis of this research was that changes in sympathetic outflow to muscle spindles can change rhythmic movement patterns. We tested this hypothesis in the masticatory system of rabbits. Rhythmic jaw movements and EMG activity induced by long-lasting electrical cortical stimulation were powerfully modulated by electrical stimulation of the peripheral stump of the cervical sympathetic nerve (CSN). This modulation manifested itself as a consistent and marked reduction in the excursion of the mandibular movements (often preceded by a transient modest enhancement), which could be attributed mainly to corresponding changes in masseter muscle activity. These changes outlasted the duration of CSN stimulation. In some of the cortically evoked rhythmic jaw movements (CRJMs) changes in masticatory frequency were also observed. When the jaw-closing muscles were subjected to repetitive ramp-and-hold force pulses, the CRMJs changed characteristics. Masseter EMG activity was strongly enhanced and digastric EMG slightly decreased. This change was considerably depressed during CSN stimulation. These effects of CSN stimulation are similar in sign and time course to the depression exerted by sympathetic activity on the jaw-closing muscle spindle discharge. It is suggested that the change in proprioceptive information induced by an increase in sympathetic outflow (a) has important implications even under normal conditions for the control of motor function in states of high sympathetic activity, and (b) is one of the mechanisms responsible for motor impairment under certain pathological conditions such as chronic musculoskeletal head-neck disorders, associated with stress conditions.

  10. Electric sympathetic block: a review of electrotherapy physics.

    Science.gov (United States)

    Schwartz, R G

    1991-01-01

    Electric sympathetic block is the procedure whereby blockage of the sympathetic nerve fiber is achieved by applying controlled electrical pulses via electrodes placed on the skin. An electric block of the sympathetic fiber can occur with a direct monophasic current to achieve an anodal block, a middle-frequency or Endosan current to effect sustained depolarization, or an interferential current to achieve a fatiguing effect. The physics and theoretical framework underlying the currents used in this procedure will be reviewed.

  11. Diffused and sustained inhibitory effects of intestinal electrical stimulation on intestinal motility mediated via sympathetic pathway.

    Science.gov (United States)

    Zhao, Xiaotuan; Yin, Jieyun; Wang, Lijie; Chen, Jiande D Z

    2014-06-01

    The aims were to investigate the energy-dose response effect of intestinal electrical stimulation (IES) on small bowel motility, to compare the effect of forward and backward IES, and to explore the possibility of using intermittent IES and mechanism of IES on intestinal motility. Five dogs implanted with a duodenal cannula and one pair of intestinal serosal electrodes were studied in five sessions: 1) energy-dose response study; 2) forward IES; 3) backward IES; 4) intermittent IES vs. continuous IES; 5) administration of guanethidine. The contractile activity and tonic pressure of the small intestine were recorded. The duration of sustained effect after turning off IES was manually calculated. 1) IES with long pulse energy dose dependently inhibited contractile activity and tonic pressure of the small intestine (p intestine depended on the energy of IES delivered (p intestine. 5) Guanethidine blocked the inhibitory effect of IES on intestinal motility. IES with long pulses inhibits small intestinal motility; the effect is energy-dose dependent, diffused, and sustained. Intermittent IES has the same efficacy as the continuous IES in inhibiting small intestinal motility. Forward and backward IES have similar inhibitory effects on small bowel motility. This IES-induced inhibitory effect is mediated via the sympathetic pathway. © 2013 International Neuromodulation Society.

  12. Effect of percutaneous renal sympathetic nerve radiofrequency ablation in patients with severe heart failure.

    Science.gov (United States)

    Dai, Qiming; Lu, Jing; Wang, Benwen; Ma, Genshan

    2015-01-01

    This study aimed to investigate the clinical feasibility and effects of percutaneous renal sympathetic nerve radiofrequency ablation in patients with heart failure. A total of 20 patients with heart failure were enrolled, aged from 47 to 75 years (63±10 years). They were divided into the standard therapy (n = 10), and renal nerve radiofrequency ablation groups (n = 10). There were 15 males and 5 female patients, including 8 ischemic cardiomyopathy, 8 dilated cardiomyopathy, and 8 hypertensive cardiopathy. All of the patients met the criteria of New York Heart Association classes III-IV cardiac function. Patients with diabetes and renal failure were excluded. Percutaneous renal sympathetic nerve radiofrequency ablation was performed on the renal artery wall under X-ray guidance. Serum electrolytes, neurohormones, and 24 h urine volume were recorded 24 h before and after the operation. Echocardiograms were performed to obtain left ventricular ejection fraction at baseline and 6 months. Heart rate, blood pressure, symptoms of dyspnea and edema were also monitored. After renal nerve ablation, 24 h urine volume was increased, while neurohormone levels were decreased compared with those of pre-operation and standard therapy. No obvious change in heart rate or blood pressure was recorded. Symptoms of heart failure were improved in patients after the operation. No complications were recorded in the study. Percutaneous renal sympathetic nerve radiofrequency ablation may be a feasible, safe, and effective treatment for the patients with severe congestive heart failure.

  13. Reflex sympathetic dystrophy following pacemaker insertion.

    Science.gov (United States)

    Londhey, Vikram A; Singh, Nishant; Kini, Seema

    2011-09-01

    A 55 year old male presented with pain and swelling over dorsum of right hand and small joints, and loss of sweating over right hand since two months. He was a known case of mitral valve prolapse (MVP) with mitral regurgitation and complete heart block for which pacemaker was implanted 1 year back. Bilateral wrist X-ray was suggestive of pronounced demineralization (osteopenia) in the right hand. He was thus diagnosed to have reflex sympathetic dystrophy syndrome (RSDS) considered to be induced by pacemaker insertion. After treatment with amitryptiline and indomethacin his symptoms dramatically improved.

  14. Dynamics of neuro-effector coupling at 'cardiac sympathetic' synapses.

    Science.gov (United States)

    Prando, Valentina; Da Broi, Francesca; Franzoso, Mauro; Plazzo, Anna Pia; Pianca, Nicola; Francolini, Maura; Basso, Cristina; Kay, Matthew W; Zaglia, Tania; Mongillo, Marco

    2018-03-10

    Cardiac sympathetic neurons (SNs) finely tune the rate and strength of heart contractions to match the blood demand, both at rest and during acute stresses, through the release of norepinephrine (NE). Junctional sites at the interface between the two cell types have been observed, but whether direct neuro-cardiac coupling has a role in heart physiology has not thus far been clearly demonstrated. We investigated the dynamics of SN/cardiomyocyte intercellular signalling, both by FRET-based imaging of cAMP in co-cultures, as a readout of cardiac β-AR activation, and in vivo, using optogenetics in transgenic mice with SN-specific expression of Channelrhodopsin-2. We demonstrate that SNs and cardiomyocytes interact at specific sites both in the human and rodent heart, and in co-cultures. Accordingly, neuronal activation elicited intracellular cAMP increases only in directly contacted myocytes and cell-cell coupling utilized a junctional extracellular signalling domain with elevated NE concentration. In the living mouse, optogenetic activation of cardiac SNs innervating the sino-atrial node resulted in an instantaneous chronotropic effect, which shortened the heartbeat interval with single beat precision. Remarkably, inhibition of the optogenetically elicited chronotropic responses required a high dose of propranolol (20-50 mg/Kg), suggesting that sympathetic neurotransmission in the heart occurs at locally elevated NE concentration. Our in vitro and in vivo data suggest that the control of cardiac function, by SNs, occurs via direct intercellular coupling due to the establishment of a specific junctional-site. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  15. Sympathetically-induced changes in microvascular cerebral blood flow and in the morphology of its low-frequency waves.

    Science.gov (United States)

    Deriu, F; Roatta, S; Grassi, C; Urciuoli, R; Micieli, G; Passatore, M

    1996-06-10

    The effect of bilateral cervical sympathetic nerve stimulation on microvascular cerebral blood flow, recorded at various depths in the parietal lobe and in ponto-mesencephalic areas, was investigated by laser-Doppler flowmetry in normotensive rabbits. These areas were chosen as representative of the vascular beds supplied by the carotid and vertebro-basilar systems, which exhibit different degrees of sympathetic innervation, the former being richer than the latter. Sympathetic stimulation at 30 imp/s affects cerebral blood flow in 77% of the parietal lobe and in 43% of the ponto-mesencephalic tested areas. In both cases the predominant effect was a reduction in blood flow (14.7 +/- 5.1% and 4.1 +/- 2.4%, respectively). The extent of the reduction in both areas was less if the stimulation frequency was decreased. Sometimes mean cerebral blood flow showed a small and transient increase, mainly in response to low-frequency stimulation. The morphology was analysed of low-frequency spontaneous oscillations in cerebral blood flow, attributed to vasomotion. Present in 41% of the tested areas (frequency 4-12 cycles/min, peak-to-peak amplitude 10-40% of mean value), these waves decreased in amplitude and increased in frequency during sympathetic stimulation, irrespective of changes in mean flow. The possibility has been proposed that the sympathetic action on low-frequency spontaneous oscillations may contribute to the protective influence that this system is known to exert on the blood-brain barrier in hypertension.

  16. Sympathetic nervous system overactivity and its role in the development of cardiovascular disease.

    Science.gov (United States)

    Malpas, Simon C

    2010-04-01

    This review examines how the sympathetic nervous system plays a major role in the regulation of cardiovascular function over multiple time scales. This is achieved through differential regulation of sympathetic outflow to a variety of organs. This differential control is a product of the topographical organization of the central nervous system and a myriad of afferent inputs. Together this organization produces sympathetic responses tailored to match stimuli. The long-term control of sympathetic nerve activity (SNA) is an area of considerable interest and involves a variety of mediators acting in a quite distinct fashion. These mediators include arterial baroreflexes, angiotensin II, blood volume and osmolarity, and a host of humoral factors. A key feature of many cardiovascular diseases is increased SNA. However, rather than there being a generalized increase in SNA, it is organ specific, in particular to the heart and kidneys. These increases in regional SNA are associated with increased mortality. Understanding the regulation of organ-specific SNA is likely to offer new targets for drug therapy. There is a need for the research community to develop better animal models and technologies that reflect the disease progression seen in humans. A particular focus is required on models in which SNA is chronically elevated.

  17. Effects of cervical sympathetic nerve stimulation on the cerebral microcirculation: possible clinical implications.

    Science.gov (United States)

    Passatore, M; Deriu, F; Roatta, S; Grassi, C; Micieli, G

    1996-01-01

    The action of bilateral cervical sympathetic nerve (CSN) stimulation on mean cerebral blood flow (CBF) and on its rhythmical fluctuations was studied in normotensive rabbits by using laser-Doppler flowmetry (LDF). A reduction in mean CBF, mediated by alpha-adrenoceptors, was the predominant effect; it was more often present and larger in size in the vascular beds supplied by the carotid than in those supplied by the vertebro-basilar system. This suggests that the sympathetic action facilitates a redistribution of blood flow to the brain stem. The effect induced by CSN stimulation on CBF spontaneous oscillations was a consistent decrease in amplitude and an increase in frequency, irrespective of the changes produced on the mean level of CBF. The possible implications of the sympathetic action on the state of the blood-brain barrier (BBB) are discussed. Experimental and clinical data dealing with the influence of sympathetic activation on the cerebrovascular system have been compared. As a result the possibility of analysing the spontaneous oscillations of CBF for clinical purposes is suggested.

  18. Using a forehead reflectance pulse oximeter to detect changes in sympathetic tone.

    Science.gov (United States)

    Wendelken, Suzanne M; McGrath, Susan P; Akay, Metin; Blike, George T

    2004-01-01

    The extreme conditions of combat and multi-casualty rescue often make field triage difficult and put the medic or first responder at risk. In an effort to improve field triage, we have developed an automated remote triage system called ARTEMIS (automated remote triage and emergency management information system) for use in the battlefield or disaster zone. Common to field injuries is a sudden change in arterial pressure resulting from massive blood loss or shock. In effort to stabilize the arterial pressure, the sympathetic system is strongly activated and sympathetic tone is increased. This preliminary research seeks to empirically demonstrate that a forehead reflectance pulse oximeter is a viable sensor for detecting sudden changes in sympathetic tone. We performed the classic supine-standing experiment and collected the raw waveform, the photoplethysmogram (PPG), continuously using a forehead reflectance pulse oximeter. The resulting waveform was processed in Matlab using various spectral analysis techniques (FFT and AR). Our preliminary results show that a relative ratio analysis (low frequency power/high frequency power) for both the raw PPG signal and its derived pulse statistics (height, beat-to-beat interval) is a useful technique for detecting change in sympathetic tone resulting from positional change.

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

    International Nuclear Information System (INIS)

    Guimarães, Sarita Lígia Pessoa de Melo Machado; Brandão, Simone Cristina Soares; Andrade, Luciana Raposo; Maia, Rafael José Coelho; Markman Filho, Brivaldo

    2015-01-01

    Chemotherapy with anthracyclines and trastuzumab can cause cardiotoxicity. Alteration of cardiac adrenergic function assessed by metaiodobenzylguanidine labeled with iodine-123 ( 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 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 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 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 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 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 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 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.

  1. Renal sympathetic denervation: MDCT evaluation of the renal arteries.

    LENUS (Irish Health Repository)

    Hutchinson, Barry D

    2013-08-01

    Percutaneous transluminal renal sympathetic denervation is a new treatment of refractory systemic hypertension. The purpose of this study was to assess the clinical utility of MDCT to evaluate the anatomic configuration of the renal arteries in the context of renal sympathetic denervation.

  2. The Effect of Sympathetic Antagonists on the Antidepressant Action ...

    African Journals Online (AJOL)

    Alprazolam is an anti-anxiety drug shown to be effective in the treatment of depression. In this study, the effect of sympathetic receptor antagonists on alprazolam–induced antidepressant action was studied using a mouse model of forced swimming behavioral despair. The interaction of three sympathetic receptor ...

  3. Epithelioid sarcoma presenting as the reflex sympathetic dystrophy syndrome.

    Science.gov (United States)

    Summers, C. L.; Shahi, M.

    1987-01-01

    A case of reflex sympathetic dystrophy caused by an epithelioid sarcoma is presented. This is the first report of a local peripheral tumour associated with the reflex sympathetic dystrophy syndrome. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:3671265

  4. Reflex sympathetic dystrophy: Early treatment and psychological aspects

    NARCIS (Netherlands)

    Geertzen, J.H.B.; De Bruijn, H.; De Bruijn-Kofman, A.T.; Arendzen, J.H.

    1994-01-01

    We report the results of two prospective studies of early treatment and psychological aspects in a series of 26 patients with sympathetic reflex dystrophy of the hand in which treatment was started within 3 months after diagnosis. Ismelin blocks is an often used therapy in sympathetic reflex

  5. Macrophage depletion suppresses sympathetic hyperinnervation following myocardial infarction

    NARCIS (Netherlands)

    Wernli, G.; Hasan, W.; Bhattacherjee, A.; Rooijen, van N.; 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,

  6. Rate of rise in diastolic blood pressure influences vascular sympathetic response to mental stress

    Science.gov (United States)

    El Sayed, Khadigeh; Macefield, Vaughan G.; Hissen, Sarah L.; Joyner, Michael J.

    2016-01-01

    Key points Research indicates that individuals may experience a rise (positive responders) or fall (negative responders) in muscle sympathetic nerve activity (MSNA) during mental stress.In this study, we examined the early blood pressure responses (including the peak, time of peak and rate of rise in blood pressure) to mental stress in positive and negative responders.Negative MSNA responders to mental stress exhibit a more rapid rise in diastolic pressure at the onset of the stressor, suggesting a baroreflex‐mediated suppression of MSNA. In positive responders there is a more sluggish rise in blood pressure during mental stress, which appears to be MSNA‐driven.This study suggests that whether MSNA has a role in the pressor response is dependent upon the reactivity of blood pressure early in the task. Abstract Research indicates that individuals may experience a rise (positive responders) or fall (negative responders) in muscle sympathetic nerve activity (MSNA) during mental stress. The aim was to examine the early blood pressure response to stress in positive and negative responders and thus its influence on the direction of change in MSNA. Blood pressure and MSNA were recorded continuously in 21 healthy young males during 2 min mental stressors (mental arithmetic, Stroop test) and physical stressors (cold pressor, handgrip exercise, post‐exercise ischaemia). Participants were classified as negative or positive responders according to the direction of the mean change in MSNA during the stressor tasks. The peak changes, time of peak and rate of changes in blood pressure were compared between groups. During mental arithmetic negative responders experienced a significantly greater rate of rise in diastolic blood pressure in the first minute of the task (1.3 ± 0.5 mmHg s−1) compared with positive responders (0.4 ± 0.1 mmHg s−1; P = 0.03). Similar results were found for the Stroop test. Physical tasks elicited robust parallel increases in blood

  7. Frequency domain analysis of electrooculogram and its correlation with cardiac sympathetic function.

    Science.gov (United States)

    Kuo, Terry B J; Yang, Cheryl C H

    2009-05-01

    To test the hypothesis that electrooculogram contains information on autonomic functions, correlation analyses of electrooculogram and heart rate variability (HRV) parameters during night sleep and over 24 h were performed on 24 healthy young volunteers (12 women and 12 men). Continuous frequency-domain analysis revealed repeated emergence of electrooculogram low-frequency power (PEOG, 0.05-0.5 Hz) during night sleep. The change in the PEOG, when natural log transformed, was graded rather than all or nothing. The PEOG was not correlated with high-frequency power (HF, 0.15-0.4 Hz) of HRV. In contrast, the PEOG was significantly correlated with R-R interval (r=-0.46+/-0.15; mean+/-SD, PHz) to HF ratio (LF/HF) of HRV (r=0.49+/-0.10, P<0.05). The correlation coefficient between PEOG and R-R interval and between PEOG and LF/HF became even larger (r=-0.68+/-0.08 and 0.58+/-0.09, respectively) when 24-h recordings were analyzed. There was no significant difference in the correlation between women and men. We concluded that the electrooculogram, as analyzed in the frequency domain, contains information on sympathetic activity not only during night sleep but also throughout day and night in healthy young people.

  8. No relation between sympathetic outflow to muscles and respiratory function in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Shindo, Kazumasa; Tsuchiya, Mai; Ichinose, Yuta; Onohara, Akiko; Fukumoto, Megumi; Koh, Kishin; Takaki, Ryusuke; Yamashiro, Nobuo; Kobayashi, Fumikazu; Nagasaka, Takamura; Takiyama, Yoshihisa

    2015-11-15

    In amyotrophic lateral sclerosis (ALS), not only impairment of motor neurons but also impairment of the autonomic nervous system has been demonstrated by previous physiological studies. Several investigators have reported a correlation between autonomic dysfunction and respiratory dysfunction in ALS. This study analyzed the relation between parameters of respiratory function and muscle sympathetic nerve activity (MSNA) in a large number of ALS patients. In 50 patients with ALS (mean age (SD): 62.1 (11.7) years), MSNA, heart rate (HR), and blood pressure (BP) were recorded simultaneously. The arterial oxygen content (PaO2), arterial carbon dioxide content (PaCO2), and forced vital capacity expressed as a percentage of the predicted value for healthy controls (%VC) were determined as parameters of respiratory function. There were no significant correlations between MSNA and PaO2, PaCO2, %VC, or the disability score. Analysis of chronological changes in 14 patients examined twice showed that the disability score and PaCO2 were significantly increased, and %VC was significantly more decreased at the second examination compared with the first examination (prespiratory function in ALS patients is not associated with changes of quantitative MSNA parameters, which may suggest that abnormality of the autonomic nervous system is a primary feature of ALS. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Differential Toxicities of Intraneurally Injected Mercuric Chloride for Sympathetic and Somatic Motor Fibers: An Ultrastructural Study

    Directory of Open Access Journals (Sweden)

    Shih-Jung Cheng

    2011-02-01

    Conclusion: This study demonstrated an undue susceptibility of sympathetic fibers to mercury intoxication. The mechanisms that underlie the selective reaction of sympathetic fibers to mercury warrant further investigation.

  10. Sympathetic block by metal clips may be a reversible operation

    DEFF Research Database (Denmark)

    Thomsen, Lars L; Mikkelsen, Rasmus T; Derejko, Miroslawa

    2014-01-01

    the sympathetic chain vary tremendously. Most surgeons transect or resect the sympathetic chain, but application of a metal clip that blocks transmission of nerve impulses in the sympathetic chain is used increasingly worldwide. This approach offers potential reversibility if patients regret surgery......, but the question of reversibility remains controversial. Two recent experimental studies found severe histological signs of nerve damage 4-6 weeks after clip removal, but they only used conventional histopathological staining methods. METHODS: Thoracoscopic clipping of the sympathetic trunk was performed in adult...... sheep, and the clip was removed thoracoscopically after 7 days. Following another 4 weeks (n = 6) or 12 weeks (n = 3), the sympathetic trunks were harvested and analysed by conventional and specific nerve tissue immunohistochemical stains (S100, neurofilament protein and synaptophysin...

  11. Modulation operated by the sympathetic nervous system on jaw reflexes and masticatory movement.

    Science.gov (United States)

    Passatore, Magda; Roatta, Silvestro

    2007-04-01

    The sympathetic nervous system (SNS), that is activated under condition of physical, psychological and psychosocial stress, affects force production and fatigability of muscles by controlling both muscle blood flow and the intracellular contractile mechanism. In addition SNS may affect motor function by modulating afferent activity from muscle spindles that are highly concentrated in jaw-closing muscles. Possible implications of these actions on masticatory function and myofascial pain are discussed.

  12. Excessive parasympathetic responses to sympathetic challenges: a treatable, hidden, dynamic autonomic imbalance

    OpenAIRE

    Bellin, David L.; DePace, Nicholas L.; Bulgarelli, Robert J.; Li, Peng; Colombo, Joe

    2015-01-01

    Background: A common assumption with autonomic assessment is that one branch opposes the other. With independent measures of parasympathetic (P) and sympathetic (S) activity, based on concurrent time-frequency analysis of respiratory activity and heart rate variability, this assumption has been challenged. Clinical observations of unprovoked P-excess during S-stimulation have been associated with treatable, abnormal responses. Method: Serial autonomic profiling of 12,967 patients was perfo...

  13. Analyzing compound activity records and promiscuity degrees in light of publication statistics.

    Science.gov (United States)

    Hu, Ye; Bajorath, Jürgen

    2016-01-01

    For the generation of contemporary databases of bioactive compounds, activity information is usually extracted from the scientific literature. However, when activity data are analyzed, source publications are typically no longer taken into consideration. Therefore, compound activity data selected from ChEMBL were traced back to thousands of original publications, activity records including compound, assay, and target information were systematically generated, and their distributions across the literature were determined. In addition, publications were categorized on the basis of activity records. Furthermore, compound promiscuity, defined as the ability of small molecules to specifically interact with multiple target proteins, was analyzed in light of publication statistics, thus adding another layer of information to promiscuity assessment. It was shown that the degree of compound promiscuity was not influenced by increasing numbers of source publications. Rather, most non-promiscuous as well as promiscuous compounds, regardless of their degree of promiscuity, originated from single publications, which emerged as a characteristic feature of the medicinal chemistry literature.

  14. A data repository and analysis framework for spontaneous neural activity recordings in developing retina.

    Science.gov (United States)

    Eglen, Stephen John; Weeks, Michael; Jessop, Mark; Simonotto, Jennifer; Jackson, Tom; Sernagor, Evelyne

    2014-03-26

    During early development, neural circuits fire spontaneously, generating activity episodes with complex spatiotemporal patterns. Recordings of spontaneous activity have been made in many parts of the nervous system over the last 25 years, reporting developmental changes in activity patterns and the effects of various genetic perturbations. We present a curated repository of multielectrode array recordings of spontaneous activity in developing mouse and ferret retina. The data have been annotated with minimal metadata and converted into HDF5. This paper describes the structure of the data, along with examples of reproducible research using these data files. We also demonstrate how these data can be analysed in the CARMEN workflow system. This article is written as a literate programming document; all programs and data described here are freely available. 1. We hope this repository will lead to novel analysis of spontaneous activity recorded in different laboratories. 2. We encourage published data to be added to the repository. 3. This repository serves as an example of how multielectrode array recordings can be stored for long-term reuse.

  15. Nonselective Blocking of the Sympathetic Nervous System Decreases Detrusor Overactivity in Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Chang-Shin Park

    2012-04-01

    Full Text Available The involuntary dual control systems of the autonomic nervous system (ANS in the bladder of awake spontaneously hypertensive rats (SHRs were investigated through simultaneous registrations of intravesical and intraabdominal pressures to observe detrusor overactivity (DO objectively as a core symptom of an overactive bladder. SHRs (n = 6 showed the features of overactive bladder syndrome during urodynamic study, especially DO during the filling phase. After injection of the nonselective sympathetic blocking agent labetalol, DO disappeared in 3 of 6 SHRs (50%. DO frequency decreased from 0.98 ± 0.22 min−1 to 0.28 ± 0.19 min−1 (p < 0.01, and DO pressure decreased from 3.82 ± 0.57 cm H2O to 1.90 ± 0.86 cm H2O (p < 0.05. This suggests that the DO originating from the overactive parasympathetic nervous system is attenuated by the nonselective blocking of the sympathetic nervous system. The detailed mechanism behind this result is still not known, but parasympathetic overactivity seems to require overactive sympathetic nervous system activity in a kind of balance between these two systems. These findings are consistent with recent clinical findings suggesting that patients with idiopathic overactive bladder may have ANS dysfunction, particularly a sympathetic dysfunction. The search for newer and better drugs than the current anticholinergic drugs as the mainstay for overactive bladder will be fueled by our research on these sympathetic mechanisms. Further studies of this principle are required.

  16. The MEK-ERK pathway negatively regulates bim expression through the 3' UTR in sympathetic neurons

    Science.gov (United States)

    2011-01-01

    Background Apoptosis plays a critical role during neuronal development and disease. Developing sympathetic neurons depend on nerve growth factor (NGF) for survival during the late embryonic and early postnatal period and die by apoptosis in its absence. The proapoptotic BH3-only protein Bim increases in level after NGF withdrawal and is required for NGF withdrawal-induced death. The regulation of Bim expression in neurons is complex and this study describes a new mechanism by which an NGF-activated signalling pathway regulates bim gene expression in sympathetic neurons. Results We report that U0126, an inhibitor of the prosurvival MEK-ERK pathway, increases bim mRNA levels in sympathetic neurons in the presence of NGF. We find that this effect is independent of PI3-K-Akt and JNK-c-Jun signalling and is not mediated by the promoter, first exon or first intron of the bim gene. By performing 3' RACE and microinjection experiments with a new bim-LUC+3'UTR reporter construct, we show that U0126 increases bim expression via the bim 3' UTR. We demonstrate that this effect does not involve a change in bim mRNA stability and by using PD184352, a specific MEK1/2-ERK1/2 inhibitor, we show that this mechanism involves the MEK1/2-ERK1/2 pathway. Finally, we demonstrate that inhibition of MEK/ERK signalling independently reduces cell survival in NGF-treated sympathetic neurons. Conclusions These results suggest that in sympathetic neurons, MEK-ERK signalling negatively regulates bim expression via the 3' UTR and that this regulation is likely to be at the level of transcription. This data provides further insight into the different mechanisms by which survival signalling pathways regulate bim expression in neurons. PMID:21762482

  17. Pmch-deficiency in rats is associated with normal adipocyte differentiation and lower sympathetic adipose drive.

    Directory of Open Access Journals (Sweden)

    Joram D Mul

    Full Text Available The orexigenic neuropeptide melanin-concentrating hormone (MCH, a product of Pmch, is an important mediator of energy homeostasis. Pmch-deficient rodents are lean and smaller, characterized by lower food intake, body-, and fat mass. Pmch is expressed in hypothalamic neurons that ultimately are components in the sympathetic nervous system (SNS drive to white and interscapular brown adipose tissue (WAT, iBAT, respectively. MCH binds to MCH receptor 1 (MCH1R, which is present on adipocytes. Currently it is unknown if Pmch-ablation changes adipocyte differentiation or sympathetic adipose drive. Using Pmch-deficient and wild-type rats on a standard low-fat diet, we analyzed dorsal subcutaneous and perirenal WAT mass and adipocyte morphology (size and number throughout development, and indices of sympathetic activation in WAT and iBAT during adulthood. Moreover, using an in vitro approach we investigated the ability of MCH to modulate 3T3-L1 adipocyte differentiation. Pmch-deficiency decreased dorsal subcutaneous and perirenal WAT mass by reducing adipocyte size, but not number. In line with this, in vitro 3T3-L1 adipocyte differentiation was unaffected by MCH. Finally, adult Pmch-deficient rats had lower norepinephrine turnover (an index of sympathetic adipose drive in WAT and iBAT than wild-type rats. Collectively, our data indicate that MCH/MCH1R-pathway does not modify adipocyte differentiation, whereas Pmch-deficiency in laboratory rats lowers adiposity throughout development and sympathetic adipose drive during adulthood.

  18. Human motor cortical activity recorded with Micro-ECoG electrodes, during individual finger movements.

    Science.gov (United States)

    Wang, W; Degenhart, A D; Collinger, J L; Vinjamuri, R; Sudre, G P; Adelson, P D; Holder, D L; Leuthardt, E C; Moran, D W; Boninger, M L; Schwartz, A B; Crammond, D J; Tyler-Kabara, E C; Weber, D J

    2009-01-01

    In this study human motor cortical activity was recorded with a customized micro-ECoG grid during individual finger movements. The quality of the recorded neural signals was characterized in the frequency domain from three different perspectives: (1) coherence between neural signals recorded from different electrodes, (2) modulation of neural signals by finger movement, and (3) accuracy of finger movement decoding. It was found that, for the high frequency band (60-120 Hz), coherence between neighboring micro-ECoG electrodes was 0.3. In addition, the high frequency band showed significant modulation by finger movement both temporally and spatially, and a classification accuracy of 73% (chance level: 20%) was achieved for individual finger movement using neural signals recorded from the micro-ECoG grid. These results suggest that the micro-ECoG grid presented here offers sufficient spatial and temporal resolution for the development of minimally-invasive brain-computer interface applications.

  19. Differential sympathetic outflow to adipose depots is required for visceral fat loss in response to calorie restriction.

    Science.gov (United States)

    Sipe, L M; Yang, C; Ephrem, J; Garren, E; Hirsh, J; Deppmann, C D

    2017-04-10

    The sympathetic nervous system (SNS) regulates energy homeostasis in part by governing fatty acid liberation from adipose tissue. We first examined whether SNS activity toward discrete adipose depots changes in response to a weight loss diet in mice. We found that SNS activity toward each adipose depot is unique in timing, pattern of activation, and habituation with the most dramatic contrast between visceral and subcutaneous adipose depots. Sympathetic drive toward visceral epididymal adipose is more than doubled early in weight loss and then suppressed later in the diet when weight loss plateaued. Coincident with the decline in SNS activity toward visceral adipose is an increase in activity toward subcutaneous depots indicating a switch in lipolytic sources. In response to calorie restriction, SNS activity toward retroperitoneal and brown adipose depots is unaffected. Finally, pharmacological blockage of sympathetic activity on adipose tissue using the β3-adrenergic receptor antagonist, SR59230a, suppressed loss of visceral adipose mass in response to diet. These findings indicate that SNS activity toward discrete adipose depots is dynamic and potentially hierarchical. This pattern of sympathetic activation is required for energy liberation and loss of adipose tissue in response to calorie-restricted diet.

  20. Cardiovascular and sympathetic neural responses to handgrip and cold pressor stimuli in humans before, during and after spaceflight

    Science.gov (United States)

    Fu, Qi; Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Diedrich, Andre; Cox, James F.; Zuckerman, Julie H.; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi; hide

    2002-01-01

    Astronauts returning to Earth have reduced orthostatic tolerance and exercise capacity. Alterations in autonomic nervous system and neuromuscular function after spaceflight might contribute to this problem. In this study, we tested the hypothesis that exposure to microgravity impairs autonomic neural control of sympathetic outflow in response to peripheral afferent stimulation produced by handgrip and a cold pressor test in humans. We studied five astronauts approximately 72 and 23 days before, and on landing day after the 16 day Neurolab (STS-90) space shuttle mission, and four of the astronauts during flight (day 12 or 13). Heart rate, arterial pressure and peroneal muscle sympathetic nerve activity (MSNA) were recorded before and during static handgrip sustained to fatigue at 40 % of maximum voluntary contraction, followed by 2 min of circulatory arrest pre-, in- and post-flight. The cold pressor test was applied only before (five astronauts) and during flight (day 12 or 13, four astronauts). Mean (+/- S.E.M.) baseline heart rates and arterial pressures were similar among pre-, in- and post-flight measurements. At the same relative fatiguing force, the peak systolic pressure and mean arterial pressure during static handgrip were not different before, during and after spaceflight. The peak diastolic pressure tended to be higher post- than pre-flight (112 +/- 6 vs. 99 +/- 5 mmHg, P = 0.088). Contraction-induced rises in heart rate were similar pre-, in- and post-flight. MSNA was higher post-flight in all subjects before static handgrip (26 +/- 4 post- vs. 15 +/- 4 bursts min(-1) pre-flight, P = 0.017). Contraction-evoked peak MSNA responses were not different before, during, and after spaceflight (41 +/- 4, 38 +/- 5 and 46 +/- 6 bursts min(-1), all P > 0.05). MSNA during post-handgrip circulatory arrest was higher post- than pre- or in-flight (41 +/- 1 vs. 33 +/- 3 and 30 +/- 5 bursts min(-1), P = 0.038 and 0.036). Similarly, responses of MSNA and blood pressure

  1. Lymphocytic Meningitis in Patients with Sympathetic Ophthalmia.

    Science.gov (United States)

    Goudot, Mathilde; Groh, Matthieu; Salah, Sawsen; Monnet, Dominique; Blanche, Philippe; Brézin, Antoine P

    2017-04-01

    This study aimed at reporting lymphocytic meningitis in patients diagnosed with sympathetic ophthalmia (SO). In this single-center retrospective observational case series, we reviewed cases diagnosed with SO. We analyzed the patients' inciting injuries, the characteristics of uveitis and the cerebrospinal fluid (CSF) analyses. Nine patients were diagnosed with SO and CSF analyses were available in all cases. Four cases had lymphocytic pleocytosis, 3 of which showed marked CSF inflammation with more than 300 lymphocytes/mm 3 . The inciting event in these 3 patients was a globe perforation injury, whereas 4 patients without meningitis had SO following a surgical intervention. In this case series of patients with SO, lymphocytic meningitis was a common finding. The prevalence of meningitis in patients with SO and its value for the diagnosis of the disease needs to be further studied.

  2. Anorexia nervosa depends on adrenal sympathetic hyperactivity: opposite neuroautonomic profile of hyperinsulinism syndrome

    Directory of Open Access Journals (Sweden)

    Lechin F

    2010-09-01

    predominance of overwhelming adrenal sympathetic activity over neural sympathetic activity. This combined central and autonomic nervous system profile contrasts with that registered in patients affected by hyperinsulinism, hypoglycemia, and bulimia syndrome which depends on the absolute predominance of neural sympathetic activity.Keywords: anorexia nervosa, adrenal sympathetic activity, adrenaline, noradrenaline, eating disorders

  3. Tectonic implications of seismic activity recorded by the northern Ontario seismograph network

    International Nuclear Information System (INIS)

    Wetmiller, R.J.; Cajka, M.G.

    1989-01-01

    The northern Ontario seismograph network, which has operated under the Canadian Nuclear Fuel Waste Management Program since 1982, has provided valuable data to supplement those recorded by the Canadian national networks on earthquake activity, rockburst activity, the distribution of regional seismic velocities, and the contemporary stress field in northern Ontario. The combined networks recorded the largest earthquake known in northwestern Ontario, M 3.9 near Sioux Lookout on February 11, 1984, and many smaller earthquakes in northeastern Ontario. Focal mechanism solutions of these and older events showed high horizontal stress and thrust faulting to be dominant features of the contemporary tectonics of northern Ontario. The zone of more intense earthquake activity in western Quebec appeared to extend northwestward into the Kapuskasing area of northeastern Ontario, where an area of persistent microearthquake activity had been identified by a seismograph station near Kapuskasing. Controlled explosions of the 1984 Kapuskasing Uplift seismic profile experiment recorded on the northern Ontario seismograph network showed the presence of anomalously high LG velocities in northeastern Ontario (3.65 km/s) that when properly taken into account reduced the mislocation errors of well-recorded seismic events by 50% on average

  4. Simultaneous surface and depth neural activity recording with graphene transistor-based dual-modality probes.

    Science.gov (United States)

    Du, Mingde; Xu, Xianchen; Yang, Long; Guo, Yichuan; Guan, Shouliang; Shi, Jidong; Wang, Jinfen; Fang, Ying

    2018-05-15

    Subdural surface and penetrating depth probes are widely applied to record neural activities from the cortical surface and intracortical locations of the brain, respectively. Simultaneous surface and depth neural activity recording is essential to understand the linkage between the two modalities. Here, we develop flexible dual-modality neural probes based on graphene transistors. The neural probes exhibit stable electrical performance even under 90° bending because of the excellent mechanical properties of graphene, and thus allow multi-site recording from the subdural surface of rat cortex. In addition, finite element analysis was carried out to investigate the mechanical interactions between probe and cortex tissue during intracortical implantation. Based on the simulation results, a sharp tip angle of π/6 was chosen to facilitate tissue penetration of the neural probes. Accordingly, the graphene transistor-based dual-modality neural probes have been successfully applied for simultaneous surface and depth recording of epileptiform activity of rat brain in vivo. Our results show that graphene transistor-based dual-modality neural probes can serve as a facile and versatile tool to study tempo-spatial patterns of neural activities. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Mid-term Outcomes of Anterior Cervical Fusion for Cervical Spondylosis With Sympathetic Symptoms.

    Science.gov (United States)

    Li, Jun; Jiang, Dong-Jie; Wang, Xin-Wei; Yuan, Wen; Liang, Lei; Wang, Zhan-Chao

    2016-07-01

    Prospective study. The purpose of this study is to elucidate mid-term outcomes of anterior cervical fusion for cervical spondylosis with sympathetic symptoms (CSSS). The terminology, pathogenesis, diagnosis, and treatment of CSSS remain controversial. Surgical treatment of CSSS has been rarely reported. This is the first prospective study to evaluate the mid-term outcome of surgical treatment of CSSS. Thirty-one patients who were diagnosed with CSSS in 2006 were evaluated prospectively. All patients were assigned to undergo anterior cervical fusion with posterior longitudinal ligament (PLL) resection and followed up for ≥5 years. Sympathetic symptoms such as vertigo, headache, and tinnitus, etc. were evaluated using the sympathetic symptom 20-point score. Neurological status was assessed using the Japanese Orthopedic Association (JOA) score. Clinical and radiologic data were prospectively collected before surgery, and at 1 week, 2 months, 6 months, 2 years, and 5 years after surgery. Surgical complications and morbidities of other diseases during the follow-up were also recorded. The mean 20-point score decreased significantly from 7.3±3.5 before surgery to 2.2±2.7 at the final follow-up (P<0.001), giving a mean recovery rate of 66.1%±50.3%. Good to excellent results were attained in 80.6% of these patients. The sympathetic symptoms were relieved in 23 of the 31 patients in the early postoperative period, and 5 patients in 2 months. No relief of sympathetic symptoms was found in 3 patients. The mean JOA score improved significantly from 12.0±1.9 before surgery to 14.8±1.5 by the end of the follow-up (P<0.001). No late neurological deterioration was found in this group. The mid-term outcomes of anterior cervical fusion with PLL resection for CSSS have been satisfactory. Differential diagnosis before surgery is of great importance. PLL may play a role in presenting sympathetic symptoms.

  6. Techniques for extracting single-trial activity patterns from large-scale neural recordings

    Science.gov (United States)

    Churchland, Mark M; Yu, Byron M; Sahani, Maneesh; Shenoy, Krishna V

    2008-01-01

    Summary Large, chronically-implanted arrays of microelectrodes are an increasingly common tool for recording from primate cortex, and can provide extracellular recordings from many (order of 100) neurons. While the desire for cortically-based motor prostheses has helped drive their development, such arrays also offer great potential to advance basic neuroscience research. Here we discuss the utility of array recording for the study of neural dynamics. Neural activity often has dynamics beyond that driven directly by the stimulus. While governed by those dynamics, neural responses may nevertheless unfold differently for nominally identical trials, rendering many traditional analysis methods ineffective. We review recent studies – some employing simultaneous recording, some not – indicating that such variability is indeed present both during movement generation, and during the preceding premotor computations. In such cases, large-scale simultaneous recordings have the potential to provide an unprecedented view of neural dynamics at the level of single trials. However, this enterprise will depend not only on techniques for simultaneous recording, but also on the use and further development of analysis techniques that can appropriately reduce the dimensionality of the data, and allow visualization of single-trial neural behavior. PMID:18093826

  7. Sympathetic denervation of one white fat depot changes norepinephrine content and turnover in intact white and brown fat depots

    Science.gov (United States)

    Harris, Ruth B.S.

    2013-01-01

    It is well established that the sympathetic nervous system regulates adipocyte metabolism and recently it has been reported that sensory afferents from white fat overlap anatomically with sympathetic efferents to white fat. The studies described here characterize the response of intact fat pads to selective sympathectomy (local 6-hydroxydopamine injections) of inguinal (ING) or epididymal (EPI) fat in male NIH Swiss mice and provide in vivo evidence for communication between individual white and brown fat depots. The contralateral ING pad, both EPI pads, perirenal and mesenteric pads were significantly enlarged four weeks after denervating one ING pad, but only intrascapular brown fat (IBAT) increased when both ING pads were denervated. Denervation of one or both EPI pad had no effect on fat depot weights. In an additional experiment, NE turnover was inhibited in ING, retroperitoneal, mesenteric and IBAT two days after denervation of both EPI or of both ING pads. NE content was reduced to 10-30% of control values in all fat depots. There was no relation between early changes in NE turnover and fat pad weight 4 weeks after denervation, even though the reduction in NE content of intact fat pads was maintained. These data demonstrate that there is communication among individual fat pads, presumably through central integration of activity of sensory afferent and sympathetic efferent fibers,that changes sympathetic drive to white adipose tissue in a unified manner. In specific situations, removal of sympathetic efferents to one pad induces a compensatory enlargement of other intact depots. PMID:22513494

  8. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

    Science.gov (United States)

    2012-01-01

    Background Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. Methods We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. Results We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Conclusion Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee’s nervous system. PMID:22882763

  9. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

    Directory of Open Access Journals (Sweden)

    Huang Stephanie

    2012-08-01

    Full Text Available Abstract Background Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. Methods We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. Results We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Conclusion Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee’s nervous system.

  10. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface.

    Science.gov (United States)

    Huang, Stephanie; Ferris, Daniel P

    2012-08-10

    Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user's nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee's nervous system.

  11. Spike Sorting of Muscle Spindle Afferent Nerve Activity Recorded with Thin-Film Intrafascicular Electrodes

    Directory of Open Access Journals (Sweden)

    Milan Djilas

    2010-01-01

    Full Text Available Afferent muscle spindle activity in response to passive muscle stretch was recorded in vivo using thin-film longitudinal intrafascicular electrodes. A neural spike detection and classification scheme was developed for the purpose of separating activity of primary and secondary muscle spindle afferents. The algorithm is based on the multiscale continuous wavelet transform using complex wavelets. The detection scheme outperforms the commonly used threshold detection, especially with recordings having low signal-to-noise ratio. Results of classification of units indicate that the developed classifier is able to isolate activity having linear relationship with muscle length, which is a step towards online model-based estimation of muscle length that can be used in a closed-loop functional electrical stimulation system with natural sensory feedback.

  12. Spike sorting of muscle spindle afferent nerve activity recorded with thin-film intrafascicular electrodes.

    Science.gov (United States)

    Djilas, Milan; Azevedo-Coste, Christine; Guiraud, David; Yoshida, Ken

    2010-01-01

    Afferent muscle spindle activity in response to passive muscle stretch was recorded in vivo using thin-film longitudinal intrafascicular electrodes. A neural spike detection and classification scheme was developed for the purpose of separating activity of primary and secondary muscle spindle afferents. The algorithm is based on the multiscale continuous wavelet transform using complex wavelets. The detection scheme outperforms the commonly used threshold detection, especially with recordings having low signal-to-noise ratio. Results of classification of units indicate that the developed classifier is able to isolate activity having linear relationship with muscle length, which is a step towards online model-based estimation of muscle length that can be used in a closed-loop functional electrical stimulation system with natural sensory feedback.

  13. The correlation of laboratory tests and Sympathetic Skin Response parameters by using artificial neural networks in fibromyalgia patients.

    Science.gov (United States)

    Ozkan, Ozhan; Yildiz, Murat; Köklükaya, Etem

    2012-06-01

    Fibromyalgia syndrome (FMS) is a chronic musculoskeletal disease which causes dysfunction of the autonomic nervous system. Sympathetic Skin Response (SSR) is a part of electrical impedance of body which is affected by the autonomic nervous system dysfunctions. In this study, values obtained from the results of the patients diagnosed with fibromyalgia syndrome, and healthy subjects blood samples in the laboratory conditions are recorded in Suleyman Demirel University, Faculty of Medicine, Department of Physical Medicine and Rehabilitation. SSR measurements are recorded from patients and healthy controls. Values of latency time, maximum amplitude and elapsed time between two stimulus parameters are obtained from recorded sympathetic skin response data by using Matlab software. The relationship between SSR parameters and laboratory tests is investigated by using artificial neural networks. As a result SSR seems to be a valid parameter in the classification of FMS.

  14. Regulators of human white adipose browning: evidence for sympathetic control and sexual dimorphic responses to sprint interval training.

    Directory of Open Access Journals (Sweden)

    Rebecca L Scalzo

    Full Text Available The conversion of white adipose to the highly thermogenic beige adipose tissue has been proposed as a potential strategy to counter the unfavorable consequences of obesity. Three regulators of this conversion have recently emerged but information regarding their control is limited, and contradictory. We present two studies examining the control of these regulators. Study 1: In 10 young men, the plasma concentrations of irisin and fibroblast growth factor 21 (FGF21 were determined prior to and during activation of the sympathetic nervous system via hypoxic gas breathing (FIO2 = 0.11. The measurements were performed twice, once with and once without prior/concurrent sympathetic inhibition via transdermal clonidine administration. FGF21 was unaffected by basal sympathetic inhibition (338±113 vs. 295±80 pg/mL; P = 0.43; mean±SE, but was increased during hypoxia mediated sympathetic activation (368±135; this response was abrogated (P = 0.035 with clonidine (269±93. Irisin was unaffected by sympathetic inhibition and/or hypoxia (P>0.21. Study 2: The plasma concentration of irisin and FGF21, and the skeletal muscle protein content of fibronectin type III domain containing 5 (FNDC5 was determined in 19 young adults prior to and following three weeks of sprint interval training (SIT. SIT decreased FGF21 (338±78 vs. 251±36; P = 0.046 but did not affect FNDC5 (P = 0.79. Irisin was decreased in males (127±18 vs. 90±23 ng/mL; P = 0.045 and increased in females (139±14 vs. 170±18. Collectively, these data suggest a potential regulatory role of acute sympathetic activation pertaining to the browning of white adipose; further, there appears to be a sexual dimorphic response of irisin to SIT.

  15. The strategic use of lecture recordings to facilitate an active and self-directed learning approach.

    Science.gov (United States)

    Topale, Luminica

    2016-08-12

    New learning technologies have the capacity to dramatically impact how students go about learning and to facilitate an active, self-directed learning approach. In U. S. medical education, students encounter a large volume of content, which must be mastered at an accelerated pace. The added pressure to excel on the USMLE Step 1 licensing exam and competition for residency placements, require that students adopt an informed approach to the use of learning technologies so as to enhance rather than to detract from the learning process. The primary aim of this study was to gain a better understanding of how students were using recorded lectures in their learning and how their study habits have been influenced by the technology. Survey research was undertaken using a convenience sample. Students were asked to voluntarily participate in an electronic survey comprised of 27 closed ended, multiple choice questions, and one open ended item. The survey was designed to explore students' perceptions of how recorded lectures affected their choices regarding class participation and impacted their learning and to gain an understanding of how recorded lectures facilitated a strategic, active learning process. Findings revealed that recorded lectures had little influence on students' choices to participate, and that the perceived benefits of integrating recorded lectures into study practices were related to their facilitation of and impact on efficient, active, and self-directed learning. This study was a useful investigation into how the availability of lecture capture technology influenced medical students' study behaviors and how students were making valuable use of the technology as an active learning tool.

  16. Dysregulation of Neuronal Ca2+ Channel Linked to Heightened Sympathetic Phenotype in Prohypertensive States

    OpenAIRE

    Larsen, Hege E.; Bardsley, Emma N.; Lefkimmiatis, Konstantinos; Paterson, David J.

    2016-01-01

    Hypertension is associated with impaired nitric oxide (NO)–cyclic nucleotide (CN)-coupled intracellular calcium (Ca2+) homeostasis that enhances cardiac sympathetic neurotransmission. Because neuronal membrane Ca2+ currents are reduced by NO-activated S-nitrosylation, we tested whether CNs affect membrane channel conductance directly in neurons isolated from the stellate ganglia of spontaneously hypertensive rats (SHRs) and their normotensive controls. Using voltage-clamp and cAMP–protein kin...

  17. Reflex sympathetic dystrophy: a retrospective epidemiological study of 168 patients.

    Science.gov (United States)

    Duman, Iltekin; Dincer, Umit; Taskaynatan, Mehmet Ali; Cakar, Engin; Tugcu, Ilknur; Dincer, Kemal

    2007-09-01

    This is a retrospective epidemiological study. The objective is to determine the epidemiological characteristics including the patient demographics, etiological factors, duration of symptoms, treatment modalities applied and clinical outcome of the treatment in reflex sympathetic dystrophy (RSD). Medical records of the 168 patients managed in two tertiary hospitals with the diagnosis of RSD that was made according to both IASP criteria and three-phase bone scan were reviewed. The upper limb was affected 1.5 times as commonly as the lower limb. Of the 168 cases, 10.7% were non-traumatic. In 89.3% of the patients, RSD developed after a traumatic inciting event with a predominance of fracture. In 75.6% of the patients, RSD developed due to job-related injuries. The percentage of successful clinical outcome was 72%. The percentage of the patients that did not respond to therapy was 28%. The management period is long and this causes higher therapeutic costs in addition to loss of productive effort. However, response to therapy is good. On the other hand, in approximately one third of the patients, RSD does not improve despite all therapeutic interventions. In addition to compensation costs, this potentially debilitating feature causes RSD to appear as a socioeconomic problem.

  18. Acceptance of the different denominations for reflex sympathetic dystrophy

    Science.gov (United States)

    Alvarez-Lario, B; Aretxabala-Alciba..., I; Alegre-Lopez, J; Alonso-Valdiviels..., J

    2001-01-01

    OBJECTIVE—To elucidate the real impact in the medical literature of the different denominations for reflex sympathetic dystrophy (RSD).
METHODS—A search was performed through the Medline database (WinSPIRS, SilverPlatter International, NS), from 1995 to 1999, including the following descriptors: RSD, complex regional pain syndrome (CRPS), CRPS type I, algodystrophy, Sudeck, shoulder-hand syndrome, transient osteoporosis, causalgia, and CRPS type II.
RESULTS—The descriptor RSD was detected in 576 references, algodystrophy in 54, transient osteoporosis in 42, CRPS type I in 24, Sudeck in 16, and shoulder-hand syndrome in 11. One hundred records were obtained for the descriptor causalgia and five for CRPS type II. The descriptor RSD was detected in the title of 262 references, algodystrophy in 29, transient osteoporosis in 29, CRPS type I in 15, Sudeck in 3, shoulder-hand syndrome in 5, causalgia in 17, and CRPS type II in 3 references.
CONCLUSIONS—The new CRPS terminology has not effectively replaced the old one. RSD and causalgia are the most used denominations.

 PMID:11114289

  19. Multichannel brain recordings in behaving Drosophila reveal oscillatory activity and local coherence in response to sensory stimulation and circuit activation.

    Science.gov (United States)

    Paulk, Angelique C; Zhou, Yanqiong; Stratton, Peter; Liu, Li; van Swinderen, Bruno

    2013-10-01

    Neural networks in vertebrates exhibit endogenous oscillations that have been associated with functions ranging from sensory processing to locomotion. It remains unclear whether oscillations may play a similar role in the insect brain. We describe a novel "whole brain" readout for Drosophila melanogaster using a simple multichannel recording preparation to study electrical activity across the brain of flies exposed to different sensory stimuli. We recorded local field potential (LFP) activity from >2,000 registered recording sites across the fly brain in >200 wild-type and transgenic animals to uncover specific LFP frequency bands that correlate with: 1) brain region; 2) sensory modality (olfactory, visual, or mechanosensory); and 3) activity in specific neural circuits. We found endogenous and stimulus-specific oscillations throughout the fly brain. Central (higher-order) brain regions exhibited sensory modality-specific increases in power within narrow frequency bands. Conversely, in sensory brain regions such as the optic or antennal lobes, LFP coherence, rather than power, best defined sensory responses across modalities. By transiently activating specific circuits via expression of TrpA1, we found that several circuits in the fly brain modulate LFP power and coherence across brain regions and frequency domains. However, activation of a neuromodulatory octopaminergic circuit specifically increased neuronal coherence in the optic lobes during visual stimulation while decreasing coherence in central brain regions. Our multichannel recording and brain registration approach provides an effective way to track activity simultaneously across the fly brain in vivo, allowing investigation of functional roles for oscillations in processing sensory stimuli and modulating behavior.

  20. Application of active electrode compensation to perform continuous voltage-clamp recordings with sharp microelectrodes.

    Science.gov (United States)

    Gómez-González, J F; Destexhe, A; Bal, T

    2014-10-01

    Electrophysiological recordings of single neurons in brain tissues are very common in neuroscience. Glass microelectrodes filled with an electrolyte are used to impale the cell membrane in order to record the membrane potential or to inject current. Their high resistance induces a high voltage drop when passing current and it is essential to correct the voltage measurements. In particular, for voltage clamping, the traditional alternatives are two-electrode voltage-clamp technique or discontinuous single electrode voltage-clamp (dSEVC). Nevertheless, it is generally difficult to impale two electrodes in a same neuron and the switching frequency is limited to low frequencies in the case of dSEVC. We present a novel fully computer-implemented alternative to perform continuous voltage-clamp recordings with a single sharp-electrode. To reach such voltage-clamp recordings, we combine an active electrode compensation algorithm (AEC) with a digital controller (AECVC). We applied two types of control-systems: a linear controller (proportional plus integrative controller) and a model-based controller (optimal control). We compared the performance of the two methods to dSEVC using a dynamic model cell and experiments in brain slices. The AECVC method provides an entirely digital method to perform continuous recording and smooth switching between voltage-clamp, current clamp or dynamic-clamp configurations without introducing artifacts.

  1. A wireless recording system that utilizes Bluetooth technology to transmit neural activity in freely moving animals.

    Science.gov (United States)

    Hampson, Robert E; Collins, Vernell; Deadwyler, Sam A

    2009-09-15

    A new wireless transceiver is described for recording individual neuron firing from behaving rats utilizing Bluetooth transmission technology and a processor onboard for discrimination of neuronal waveforms and associated time stamps. This universal brain activity transmitter (UBAT) is attached to rodents via a backpack and amplifier headstage and can transmit 16 channels of captured neuronal firing data via a Bluetooth transceiver chip over very large and unconstrained distances. The onboard microprocessor of the UBAT allows flexible online control over waveform isolation criteria via transceiver instruction and the two-way communication capacity allows for closed-loop applications between neural events and behavioral or physiological processes which can be modified by transceiver instructions. A detailed description of the multiplexer processing of channel data as well as examples of neuronal recordings in different behavioral testing contexts is provided to demonstrate the capacity for robust transmission within almost any laboratory environment. A major advantage of the UBAT is the long transmission range and lack of object-based line of sight interference afforded by Bluetooth technology, allowing flexible recording capabilities within multiple experimental paradigms without interruption. Continuous recordings over very large distance separations from the monitor station are demonstrated providing experimenters with recording advantages not previously available with other telemetry devices.

  2. Pseudodystrophy. A conversion disorder mimicking reflex sympathetic dystrophy.

    Science.gov (United States)

    Driessens, M; Blockx, P; Geuens, G; Dijs, H; Verheyen, G; Stassijns, G

    2002-10-01

    The authors suggest some criteria by which pseudodystrophy and reflex sympathetic dystrophy, although sharing some similar clinical features, can be distinguished as two different conditions, each requiring its own approach and management. The most important distinction is found on bone scintigraphy. In reflex sympathetic dystrophy the bone scan shows a typical increased tracer uptake (at least during stages I and II); in pseudodystrophy there is a normal or decreased tracer uptake in the affected region. Moreover the vascularization is increased in reflex sympathetic dystrophy stage I, whereas in pseudodystrophy hypovascularization is found from the beginning. The clinical features, as well as the results of technical investigations, psychological evaluation and treatment of 4 patients with pseudodystrophy are presented. The importance of distinguishing this condition from reflex sympathetic dystrophy is stressed.

  3. Cardiovascular Response Patterns to Sympathetic Stimulation by Central Hypovolemia

    NARCIS (Netherlands)

    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

  4. Imbalance between sympathetic and sensory innervation in peritoneal endometriosis.

    Science.gov (United States)

    Arnold, Julia; Barcena de Arellano, Maria L; Rüster, Carola; Vercellino, Giuseppe F; Chiantera, Vito; Schneider, Achim; Mechsner, Sylvia

    2012-01-01

    To investigate possible mechanisms of pain pathophysiology in patients with peritoneal endometriosis, a clinical study on sensory and sympathetic nerve fibre sprouting in endometriosis was performed. Peritoneal lesions (n=40) and healthy peritoneum (n=12) were immunostained and analysed with anti-protein gene product 9.5 (PGP 9.5), anti-substance P (SP) and anti-tyrosine hydroxylase (TH), specific markers for intact nerve fibres, sensory nerve fibres and sympathetic nerve fibres, respectively, to identify the ratio of sympathetic and sensory nerve fibres. In addition, immune cell infiltrates in peritoneal endometriotic lesions were analysed and the nerve growth factor (NGF) and interleukin (IL)-1β expression was correlate with the nerve fibre density. Peritoneal fluids from patients with endometriosis (n=40) and without endometriosis (n=20) were used for the in vitro neuronal growth assay. Cultured chicken dorsal root ganglia (DRG) and sympathetic ganglia were stained with anti-growth associated protein 43 (anti-GAP 43), anti-SP and anti-TH. We could detect an increased sensory and decreased sympathetic nerve fibres density in peritoneal lesions compared to healthy peritoneum. Peritoneal fluids of patients with endometriosis compared to patients without endometriosis induced an increased sprouting of sensory neurites from DRG and decreased neurite outgrowth from sympathetic ganglia. In conclusion, this study demonstrates an imbalance between sympathetic and sensory nerve fibres in peritoneal endometriosis, as well as an altered modulation of peritoneal fluids from patients with endometriosis on sympathetic and sensory innervation which might directly be involved in the maintenance of inflammation and pain. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Schwanomma From Cervical Sympathetic Chain Ganglion – A Rare Presentation

    Science.gov (United States)

    Asma, A. Affee

    2015-01-01

    Schwanommas arising from cervical sympathetic chain are tumours that are rare in occurrence. These lesions are usually difficult to differentiate from a vagal schwanomma and a carotid body tumour during the initial workup. In this report, a rarely seen huge cervical sympathetic chain schwanomma case with partial Horner’s syndrome is being presented in detail, which to our known knowledge, is one of the few cases reported in literature. PMID:26557566

  6. Schwanomma From Cervical Sympathetic Chain Ganglion - A Rare Presentation.

    Science.gov (United States)

    Asma, A Affee; Kannah, E

    2015-10-01

    Schwanommas arising from cervical sympathetic chain are tumours that are rare in occurrence. These lesions are usually difficult to differentiate from a vagal schwanomma and a carotid body tumour during the initial workup. In this report, a rarely seen huge cervical sympathetic chain schwanomma case with partial Horner's syndrome is being presented in detail, which to our known knowledge, is one of the few cases reported in literature.

  7. [Regional transient osteoporosis, and reflex sympathetic dystrophy: the same disease?].

    Science.gov (United States)

    Castellano, Karina; Plantalech, Luisa

    2005-01-01

    Complex regional pain syndrome, reflex sympathetic dystrophy, regional, transient and migratory osteoporosis, are known as a spectrum of medical conditions that present with pain, edema, erythema, localized osteoporosis and sometimes sympathetic dysfunction. Many factors which are present in these conditions, such as clinical presentation, radiologic findings and a variety of still unclear physiopathologic mechanisms are correlated. We propose that all these conditions are different periods of the same pathology.

  8. Chronic recordings of hypoglossal nerve activity in a dog model of upper airway obstruction.

    Science.gov (United States)

    Sahin, M; Durand, D M; Haxhiu, M A

    1999-12-01

    The activity of the hypoglossal nerve was recorded during pharyngeal loading in sleeping dogs with chronically implanted cuff electrodes. Three self-coiling spiral-cuff electrodes were implanted in two beagles for durations of 17, 7, and 6 mo. During quiet wakefulness and sleep, phasic hypoglossal activity was either very small or not observable above the baseline noise. Applying a perpendicular force on the submental region by using a mechanical device to narrow the pharyngeal airway passage increased the phasic hypoglossal activity, the phasic esophageal pressure, and the inspiratory time in the next breath during non-rapid-eye-movement sleep. The phasic hypoglossal activity sustained at the elevated level while the force was present and increased with increasing amounts of loading. The hypoglossal nerve was very active in rapid-eye-movement sleep, especially when the submental force was present. The data demonstrate the feasibility of chronic recordings of the hypoglossal nerve with cuff electrodes and show that hypoglossal activity has a fast and sustained response to the internal loading of the pharynx induced by applying a submental force during non-rapid-eye-movement sleep.

  9. Motivation and intention to integrate physical activity into daily school life: the JAM World Record event.

    Science.gov (United States)

    Vazou, Spyridoula; Vlachopoulos, Symeon P

    2014-11-01

    Research on the motivation of stakeholders to integrate physical activity into daily school life is limited. The purpose was to examine the motivation of stakeholders to participate in a world record physical activity event and whether motivation was associated with future intention to use activity breaks during the daily school life and future participation in a similar event. After the 2012 JAM (Just-a-Minute) World Record event, 686 adults (591 women; 76.1% participated for children motivational regulations and future intention to (a) use the activity breaks and (b) participate in the event. High intrinsic motivation and low extrinsic motivation and amotivation for participation in the next event were reported. Hierarchical regression analysis, controlling for age, gender, and occupation, showed that intrinsic forms of motivation positively predicted, whereas amotivation negatively predicted, future intention to participate in the event and use the activity breaks. Multivariate analyses of variance revealed that school-related participants were more intrinsically motivated and intended to use the activity breaks and repeat the event more than those who were not affiliated with a school. Nonschool participants reported higher extrinsic motivation and amotivation than school-related participants. © 2014 Society for Public Health Education.

  10. Abnormal bone scintigraphy and silent radiography in localized reflex sympathetic dystrophy syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Cuertero-Plaza, A.; Martinez-Miralles, E.; Sanz Marin, M.P. (Hospital Universitari del Mar, Barcelona (Spain). Dept. of Radiology and Nuclear Medicine); Benito-Ruiz, P.; Martinez-Pardo, S. (Hospital Universitari del Mar, Barcelona (Spain). Div. of Rheumatology)

    1992-05-01

    Typical, definite forms of the reflex sympathetic dystrophy syndrome present no diagnostic problems, but the diagnosis of localized or very localized forms is very difficult. In the absence of characteristic roentgenographic evidence of acute, patchy, bony demineralization in the affected extremity, scintigraphy has proven to be a valuable examination. A retrospective analysis of 6 patients with a partial form of reflex sympathetic dystrophy with negative roentgenogram results who were evaluated by bone scintigraphy is presented. In the initial clinical stages, the predominant scintigraphic pattern was a very localized and intense hyperactivity in the internal femoral condyle and/or tibial plate of the affected joint on both blood pool and static images. The increased periarticular activity showed a marked decrease in association with remission of the clinical symptoms. In conclusion, bone scintigraphy was found to be a useful tool in the diagnosis and assessment of the therapeutic response. (orig.).

  11. Effects of sympathetic histamine on vasomotor responses of blood vessels in rabbit ear to electrical stimulation.

    Science.gov (United States)

    Chen, Ying-Ying; Lv, Jun; Xue, Xiao-Yan; He, Gong-Hao; Zhou, Ying; Jia, Min; Luo, Xiao-Xing

    2010-06-01

    To investigate the effects of histamine receptor antagonists on vasoconstriction induced by electrical stimulation (ES) on posterior auricular nerve, and to explore the pre- and post-synaptic effects of sympathetic histamine on the vasomotor responses of vascular smooth muscle in rabbit ear. ES was applied to posterior auricular nerves of the whole rabbit ear at 10 Hz, 20 Hz and 40 Hz, respectively. Besides, the whole ear was perfused with different histamine receptor antagonists under constant perfusion pressure, and the changes in the flow rate of perfusate were observed. The flow rate of venous outflow was decreased by ES at all the 3 frequencies. The ES-induced vasoconstriction at 20 Hz and 40 Hz could be partly inhibited by H(1) receptor antagonist chlorpheniramine (P functions of sympathetic histamine vary from pre-synaptic modulation to post-synaptic vasoconstriction or vasodilatation, via activation of different histamine receptors.

  12. Revision on Renal Sympathetic Ablation in the Treatment of Resistant Hypertension.

    Science.gov (United States)

    Saraiva, Ana Filipa

    2016-01-01

    Hypertension is one of the most prevalent diseases in the world, with about 1 billion people affected and a possible increase to 1.5 billion by 2025. Despite advances in treatment, a proportion of patients remain resistant to conventional treatment and uncontrolled, and this can adversely affect future cardiovascular events and mortality. This alarming growth is already reflected in an important public health problem and one of the largest economic burdens of health, requiring new approaches and development of different strategies to fight this problem. This review will focus on the definition of resistant hypertension and its etiology, as well as in contemporary evidence supporting the usefulness of renal sympathetic denervation while addressing current and emerging devices, potential treatment indications in the future and unresolved issues that need to be addressed before renal sympathetic denervation can be adopted not only as a last resort exclusively for resistant hypertension. Finally an evaluation algorithm for patients with resistant hypertension which should be implemented before the execution of this technique will be proposed. Renal sympathetic denervation is a technique that possibly could have future implications in the population with hypertension, especially those with true resistant hypertension. This technique aims to reduce the renal sympathetic activation (a component in the pathophysiology of hypertension) through the destruction of the renal sympathetic nerves located in the adventitia of the renal arteries. There are several catheters that can be used; each with its specifications and therefore their selection should be made individually depending on the profile of the patient. However, a detailed pre-procedure evaluation is extremely important to exclude the large percentage of individuals with uncontrolled hypertension due to several factors that make it impossible to control blood pressure, but are likely to be corrected and as such should

  13. Doppler sonographic assessment of posttraumatic reflex sympathetic dystrophy.

    Science.gov (United States)

    Pekindil, Gökhan; Pekindil, Yesim; Sarikaya, Ali

    2003-04-01

    To reveal the arterial Doppler sonographic findings in cases of posttraumatic reflex sympathetic dystrophy Eleven patients had hand reflex sympathetic dystrophy, and 9 had foot reflex sympathetic dystrophy. The duration of symptoms ranged from 1 to 28 weeks, and the history of fracture ranged from 6 to 48 weeks. Bilateral brachial or popliteal arteries proximal to injuries were evaluated by Doppler sonography with a 7.5-MHz linear transducer. All patients also had triphasic bone scintigraphy and extremity thermography Two patients had monophasic waveforms and 4 had low-pulsatility triphasic waveforms on the affected limbs when compared with the asymptomatic limbs. All opposite asymptomatic limbs had normal triphasic waveforms in these 6 cases. Spectral analysis revealed a loss or decrease of a normal reversed flow component with a reduced pulsatility index on the affected limb. Fourteen other patients had symmetric triphasic waveforms. We observed that the patients who had stage 1 reflex sympathetic dystrophy and warm limbs with durations of symptoms of more than 2 weeks had positive Doppler sonographic findings, whereas all patients with stage 2 reflex sympathetic dystrophy and all with normal skin temperature, regardless of stage, had normal waveforms. Doppler sonography revealed loss of normal triphasic arterial waveforms in some of the cases of stage 1 disease, whereas many cases of stage 1 disease and all cases of stage 2 disease had normal findings. Therefore, we think that Doppler sonography cannot be used for the diagnosis of reflex sympathetic dystrophy but may help in assessing hemodynamic stages of the disease.

  14. 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

  15. Comparison of thermogenic sympathetic response to food intake between obese and non-obese young women.

    Science.gov (United States)

    Matsumoto, T; Miyawaki, C; Ue, H; Kanda, T; Yoshitake, Y; Moritani, T

    2001-02-01

    Sympathetic nervous system abnormality in humans is still a matter of debate. The present study was designed to examine diet-induced autonomic nervous system activity and metabolic change in obese and non-obese young women. Sixteen age- and height-matched obese and non-obese young women participated in this study. Sympathovagal activities were assessed by means of our newly developed spectral analysis procedure of heart-rate variability during the resting condition and after mixed-food ingestion (480 kcal). Energy expenditure was also measured under these two conditions. There was no significant difference in any of the parameters of the heart-rate variability between the obese group and control group during the resting condition. In the control group, both absolute values (221.5 +/- 54.5 vs. 363.8 +/- 43.7 ms2, p frequency component and global sympathetic nervous system index (1.46 +/- 0.19 vs. 3.26 +/- 0.61, p food ingestion compared with the values obtained after resting condition. However, no such sympathetic response was found in the obese group. Energy expenditure increased in the two groups after the meal, but the magnitude of the increase above the preprandial resting condition was significantly greater in the control group than in the obese group (11.2 +/- 2.3 vs. 6.7 +/- 0.8%, p food intake, which might be related to lowered capacity of thermogenesis and the state of obesity.

  16. Dissociation between neural and vascular responses to sympathetic stimulation : contribution of local adrenergic receptor function

    Science.gov (United States)

    Jacob, G.; Costa, F.; Shannon, J.; Robertson, D.; Biaggioni, I.

    2000-01-01

    Sympathetic activation produced by various stimuli, eg, mental stress or handgrip, evokes regional vascular responses that are often nonhomogeneous. This phenomenon is believed to be the consequence of the recruitment of differential central neural pathways or of a sympathetically mediated vasodilation. The purpose of this study was to determine whether a similar heterogeneous response occurs with cold pressor stimulation and to test the hypothesis that local differences in adrenergic receptor function could be in part responsible for this diversity. In 8 healthy subjects, local norepinephrine spillover and blood flow were measured in arms and legs at baseline and during sympathetic stimulation induced by baroreflex mechanisms (nitroprusside infusion) or cold pressor stimulation. At baseline, legs had higher vascular resistance (27+/-5 versus 17+/-2 U, P=0.05) despite lower norepinephrine spillover (0.28+/-0.04 versus 0.4+/-0.05 mg. min(-1). dL(-1), P=0.03). Norepinephrine spillover increased similarly in both arms and legs during nitroprusside infusion and cold pressor stimulation. On the other hand, during cold stimulation, vascular resistance increased in arms but not in legs (20+/-9% versus -7+/-4%, P=0.03). Increasing doses of isoproterenol and phenylephrine were infused intra-arterially in arms and legs to estimate beta-mediated vasodilation and alpha-induced vasoconstriction, respectively. beta-Mediated vasodilation was significantly lower in legs compared with arms. Thus, we report a dissociation between norepinephrine spillover and vascular responses to cold stress in lower limbs characterized by a paradoxical decrease in local resistance despite increases in sympathetic activity. The differences observed in adrenergic receptor responses cannot explain this phenomenon.

  17. Subfornical Organ Mediates Sympathetic and Hemodynamic Responses to Blood-borne Pro-Inflammatory Cytokines

    Science.gov (United States)

    Wei, Shun-Guang; Zhang, Zhi-Hua; Beltz, Terry G.; Yu, Yang; Johnson, Alan Kim; Felder, Robert B.

    2013-01-01

    Pro-inflammatory cytokines play an important role in regulating autonomic and cardiovascular function in hypertension and heart failure. Peripherally administered pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) act upon the brain to increase blood pressure (BP), heart rate (HR) and sympathetic nerve activity. These molecules are too large to penetrate blood brain barrier (BBB), and so the mechanisms by which they elicit these responses remain unknown. We tested the hypothesis that the subfornical organ (SFO), a forebrain circumventricular organ that lacks a BBB, plays a major role in mediating the sympathetic and hemodynamic responses to circulating pro-inflammatory cytokines. Intracarotid artery (ICA) injection of TNF-α (200 ng) or IL-1β (200 ng) dramatically increased mean BP (MBP), HR and renal sympathetic nerve activity (RSNA) in rats with sham lesions of the SFO (SFO-s). These excitatory responses to ICA TNF-α and IL-1β were significantly attenuated in SFO-lesioned (SFO-x) rats. Similarly, the increases in MBP, HR and RSNA in response to intravenous (IV) injections of TNF-α (500 ng) or IL-1β (500 ng) in SFO-s rats were significantly reduced in the SFO-x rats. Immunofluorescent staining revealed a dense distribution of the p55 TNF-α receptor and the IL-1 receptor accessory protein, a subunit of the IL-1 receptor, in the SFO. These data suggest that SFO is a predominant site in the brain at which circulating pro-inflammatory cytokines act to elicit cardiovascular and sympathetic responses. PMID:23670302

  18. [Progressive hemifacial atrophy with sympathetic nerve dysfunction of central origin].

    Science.gov (United States)

    Tsuchiya, I; Sahashi, K; Ibi, T; Iwase, S; Mano, T

    1989-09-01

    A 37-year-old unmarried man was admitted because of gait disturbance and right hemifacial atrophy. Family history was unremarkable. He had an unconscious attack at age 13 and had writer's cramp since age 15. He was thin and lipodystrophic. In reviewing his portraits, hemifacial atrophy was considered to develop in his early teens and to be progressive since then. Pigmented gum, high arched palate, mild mental retardation, pseudo-Argyll Robertson's pupil, sexual impotence, amyotrophy of the left thigh and the right calf, and a limp due to bony abnormalities was detected. Serological tests for syphilis were negative. Bone X-rays disclosed coxa-deformance. Cerebrospinal fluid. EMG, EEG, muscle biopsy and brain CT were normal. Hearing was decreased to 20-35 dB bilaterally. Plasma norepinephrine levels were 450 pg/ml in the supine position and 539 pg/ml in standing. Plasma renin activity was 5.1-5.4 ng/ml/hr. Microneurography revealed highly accentuated muscle and skin sympathetic nerve activities. Hypothermia on the feet, reduced CVR-R and decreased mydriatic response to 5% cocaine instillation were present. Intravenous infusion of norepinephrine and intradermal injection of either acetylcholine or histamine revealed normal results. In the case, sympathicotonia due to dysfunction in the central nervous system is considered to be related to the pathogenesis of hemifacial atrophy.

  19. High-resolution Observations of Sympathetic Filament Eruptions by NVST

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shangwei; Su, Yingna; Zhou, Tuanhui; Ji, Haisheng [Key Laboratory for Dark Matter and Space Science, Purple Mountain Observatory, CAS, Nanjing 210008 (China); Van Ballegooijen, Adriaan [5001 Riverwood Avenue, Sarasota, FL 34231 (United States); Sun, Xudong, E-mail: ynsu@pmo.ac.cn [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2017-07-20

    We investigate two sympathetic filament eruptions observed by the New Vacuum Solar Telescope on 2015 October 15. The full picture of the eruptions is obtained from the corresponding Solar Dynamics Observatory ( SDO )/Atmospheric Imaging Assembly (AIA) observations. The two filaments start from active region NOAA 12434 in the north and end in one large quiescent filament channel in the south. The left filament erupts first, followed by the right filament eruption about 10 minutes later. Clear twist structure and rotating motion are observed in both filaments during the eruption. Both eruptions failed, since the filaments first rise up, then flow toward the south and merge into the southern large quiescent filament. We also observe repeated activations of mini filaments below the right filament after its eruption. Using magnetic field models constructed based on SDO /HMI magnetograms via the flux rope insertion method, we find that the left filament eruption is likely to be triggered by kink instability, while the weakening of overlying magnetic fields due to magnetic reconnection at an X-point between the two filament systems might play an important role in the onset of the right filament eruption.

  20. The Effect of Transcutaneous Electrical Nerve Stimulation of Sympathetic Ganglions and Acupuncture Points on Distal Blood Flow

    Directory of Open Access Journals (Sweden)

    Fahimeh Kamali

    2017-04-01

    Full Text Available Transcutaneous electrical nerve stimulation (TENS is a widely-practiced method to increase blood flow in clinical practice. The best location for stimulation to achieve optimal blood flow has not yet been determined. We compared the effect of TENS application at sympathetic ganglions and acupuncture points on blood flow in the foot of healthy individuals. Seventy-five healthy individuals were randomly assigned to three groups. The first group received cutaneous electrical stimulation at the thoracolumbar sympathetic ganglions. The second group received stimulation at acupuncture points. The third group received stimulation in the mid-calf area as a control group. Blood flow was recorded at time zero as baseline and every 3 minutes after baseline during stimulation, with a laser Doppler flow-meter. Individuals who received sympathetic ganglion stimulation showed significantly greater blood flow than those receiving acupuncture point stimulation or those in the control group (p<0.001. Data analysis revealed that blood flow at different times during stimulation increased significantly from time zero in each group. Therefore, the application of low-frequency TENS at the thoracolumbar sympathetic ganglions was more effective in increasing peripheral blood circulation than stimulation at acupuncture points.

  1. Detecting seismic activity with a covariance matrix analysis of data recorded on seismic arrays

    Science.gov (United States)

    Seydoux, L.; Shapiro, N. M.; de Rosny, J.; Brenguier, F.; Landès, M.

    2016-03-01

    Modern seismic networks are recording the ground motion continuously at the Earth's surface, providing dense spatial samples of the seismic wavefield. The aim of our study is to analyse these records with statistical array-based approaches to identify coherent time-series as a function of time and frequency. Using ideas mainly brought from the random matrix theory, we analyse the spatial coherence of the seismic wavefield from the width of the covariance matrix eigenvalue distribution. We propose a robust detection method that could be used for the analysis of weak and emergent signals embedded in background noise, such as the volcanic or tectonic tremors and local microseismicity, without any prior knowledge about the studied wavefields. We apply our algorithm to the records of the seismic monitoring network of the Piton de la Fournaise volcano located at La Réunion Island and composed of 21 receivers with an aperture of ˜15 km. This array recorded many teleseismic earthquakes as well as seismovolcanic events during the year 2010. We show that the analysis of the wavefield at frequencies smaller than ˜0.1 Hz results in detection of the majority of teleseismic events from the Global Centroid Moment Tensor database. The seismic activity related to the Piton de la Fournaise volcano is well detected at frequencies above 1 Hz.

  2. Quality assurance records system for research and development activities in support of geologic repository programs

    International Nuclear Information System (INIS)

    Smith, J.W.; Ryder, D.E.

    1987-01-01

    The Pacific Northwest Laboratory (PNL), which is operated by Battelle Memorial Institute for the Department of Energy, is conducting site-specific research for all three candidate sites for the first geologic high-level waste repository, as well as generic research for the second repository. In conjunction with this effort, PNL has developed a quality assurance (QA) program that is applicable to all organizations that are performing research and development (R and D) activities in support of the repository programs. This QA program meets the basic and supplemental requirements of ANSI/ASME NQA-1-1983 and the Nuclear Regulatory Commission (NRC) Review Plan for QA Programs for Site Characterization of High Level Nuclear Waste Repositories. A key part of this program is the handling of QA records that may ultimately support the licensing process for the repository. This paper describes a QA records system that is flexible enough to accommodate several types of research, such as paper studies, test method development, site characterization studies, software development, and hardware design. In addition, the QA records system is acceptable to a variety of sponsors who have licensing concerns. The QA procedures and their relation to the requirements are described. Most important is the discussion on the approaches used to assure that the records are organized such that the user can readily recreate or defend data, conclusions, and recommendations resulting from the research

  3. Simultaneous Recording and Analysis of Uterine and Abdominal Muscle Electromyographic Activity in Nulliparous Women During Labor.

    Science.gov (United States)

    Qian, Xueya; Li, Pin; Shi, Shao-Qing; Garfield, Robert E; Liu, Huishu

    2017-03-01

    To record and characterize electromyography (EMG) from the uterus and abdominal muscles during the nonlabor to first and second stages of labor and to define relationships to contractions. Nulliparous patients without any treatments were used (n = 12 nonlabor stage, 48 during first stage and 33 during second stage). Electromyography of both uterine and abdominal muscles was simultaneously recorded from electrodes placed on patients' abdominal surface using filters to separate uterine and abdominal EMG. Contractions of muscles were also recorded using tocodynamometry. Electromyography was characterized by analysis of various parameters. During the first stage of labor, when abdominal EMG is absent, uterine EMG bursts temporally correspond to contractions. In the second stage, uterine EMG bursts usually occur at same frequency as groups of abdominal bursts and precede abdominal bursts, whereas abdominal EMG bursts correspond to contractions and are accompanied by feelings of "urge to push." Uterine EMG increases progressively from nonlabor to second stage of labor. (1) Uterine EMG activity can be separated from abdominal EMG events by filtering. (2) Uterine EMG gradually evolves from the antepartum stage to the first and second stages of labor. (3) Uterine and abdominal EMG reflect electrical activity of the muscles during labor and are valuable to assess uterine and abdominal muscle events that control labor. (4) During the first stage of labor uterine, EMG is responsible for contractions, and during the second stage, both uterine and abdominal muscle participate in labor.

  4. Locus coeruleus lesions and PCOS: role of the central and peripheral sympathetic nervous system in the ovarian function of rat

    Directory of Open Access Journals (Sweden)

    Farideh Zafari Zangeneh

    2012-01-01

    Full Text Available Polycystic ovary syndrome (PCOS is a complex endocrine and metabolic disorder associated with ovulatory dysfunction”. “Autonomic and central nervous systems play important roles in the regulation of ovarian physiology”. The noradrenergic nucleus locus coeruleus (LC plays a central role in the regulation of the sympathetic nervous system and synaptically connected to the preganglionic cell bodies of the ovarian sympathetic pathway and its activation is essential to trigger spontaneous or induced LH surges. This study evaluates sympathetic outflow in central and peripheral pathways in PCO rats. Objective: Our objectives in this study were (1 to estimate LC activity in rats with estradiol valerate (EV-induced PCO; (2 to antagonized alpha2a adrenoceptor in systemic conditions with yohimbine. Materials and Methods: Forty two rats were divided into two groups: 1 LC and yohimbine and 2 control. Every group subdivided in two groups: eighteen rats were treated with estradiol valerate for induction of follicular cysts and the remainders were sesame oil groups. Results: Estradiol concentration was significantly augmented by the LC lesion in PCO rats (p<0.001, while LC lesion could not alter serum concentrations of LH and FSH, like yohimbine. The morphological observations of ovaries of LC lesion rats showed follicles with hyperthecosis, but yohimbine reduced the number of cysts, increased corpus lutea and developed follicles. Conclusion: Rats with EV-induced PCO increased sympathetic activity. LC lesion and yohimbine decreased the number of cysts and yohimbine increased corpus lutea and developed follicles in PCO rats.

  5. Timing of early activity in the visual cortex as revealed by simultaneous MEG and ERG recordings.

    Science.gov (United States)

    Inui, Koji; Sannan, Hiromi; Miki, Kensaku; Kaneoke, Yoshiki; Kakigi, Ryusuke

    2006-03-01

    To clarify the latency of the earliest cortical activity in visual processing, electroretinograms (ERGs) and visual evoked magnetic fields (VEFs) following flash stimulation were recorded simultaneously in six human subjects. Flash stimuli were applied to the right eye and ERGs were recorded from a skin electrode placed on the lower lid. ERGs showed two major deflections in all subjects: an eyelid-negativity around 20 ms and a positivity around 60 ms corresponding to an a- and b-waves, respectively. The mean onset and peak latency of the earliest component of VEFs (37 M) was 30.2 and 36.9 ms, respectively. There was a linear correlation between the peak latency of the a-wave and the onset latency of the 37 M (r=0.90, P=0.011). When a single equivalent current dipole analysis was applied to the 37 M, four out of six subjects showed highly reliable results. The generator of the 37 M was estimated to be located in the striate cortex in all four subjects. Since post-receptoral activities in the retina are expected to start around the peak of the a-wave (20 ms), the early cortical activity, which appears 10 ms later than the a-wave peak, is considered to be the earliest cortical activity following flash stimulation.

  6. Continuous recording of long-chain acyl-coenzyme A synthetase activity using fluorescently labeled bovine serum albumin

    DEFF Research Database (Denmark)

    Demant, Erland J.F.; Nystrøm, Birthe T.

    2001-01-01

    acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes......acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes...

  7. Automatic prediction of rheumatoid arthritis disease activity from the electronic medical records.

    Directory of Open Access Journals (Sweden)

    Chen Lin

    Full Text Available We aimed to mine the data in the Electronic Medical Record to automatically discover patients' Rheumatoid Arthritis disease activity at discrete rheumatology clinic visits. We cast the problem as a document classification task where the feature space includes concepts from the clinical narrative and lab values as stored in the Electronic Medical Record.The Training Set consisted of 2792 clinical notes and associated lab values. Test Set 1 included 1749 clinical notes and associated lab values. Test Set 2 included 344 clinical notes for which there were no associated lab values. The Apache clinical Text Analysis and Knowledge Extraction System was used to analyze the text and transform it into informative features to be combined with relevant lab values.Experiments over a range of machine learning algorithms and features were conducted. The best performing combination was linear kernel Support Vector Machines with Unified Medical Language System Concept Unique Identifier features with feature selection and lab values. The Area Under the Receiver Operating Characteristic Curve (AUC is 0.831 (σ = 0.0317, statistically significant as compared to two baselines (AUC = 0.758, σ = 0.0291. Algorithms demonstrated superior performance on cases clinically defined as extreme categories of disease activity (Remission and High compared to those defined as intermediate categories (Moderate and Low and included laboratory data on inflammatory markers.Automatic Rheumatoid Arthritis disease activity discovery from Electronic Medical Record data is a learnable task approximating human performance. As a result, this approach might have several research applications, such as the identification of patients for genome-wide pharmacogenetic studies that require large sample sizes with precise definitions of disease activity and response to therapies.

  8. Role of the Sympathetic Nervous System and Its Modulation in Renal Hypertension

    Directory of Open Access Journals (Sweden)

    Yusuke Sata

    2018-03-01

    Full Text Available The kidneys are densely innervated with renal efferent and afferent nerves to communicate with the central nervous system. Innervation of major structural components of the kidneys, such as blood vessels, tubules, the pelvis, and glomeruli, forms a bidirectional neural network to relay sensory and sympathetic signals to and from the brain. Renal efferent nerves regulate renal blood flow, glomerular filtration rate, tubular reabsorption of sodium and water, as well as release of renin and prostaglandins, all of which contribute to cardiovascular and renal regulation. Renal afferent nerves complete the feedback loop via central autonomic nuclei where the signals are integrated and modulate central sympathetic outflow; thus both types of nerves form integral parts of the self-regulated renorenal reflex loop. Renal sympathetic nerve activity (RSNA is commonly increased in pathophysiological conditions such as hypertension and chronic- and end-stage renal disease. Increased RSNA raises blood pressure and can contribute to the deterioration of renal function. Attempts have been made to eliminate or interfere with this important link between the brain and the kidneys as a neuromodulatory treatment for these conditions. Catheter-based renal sympathetic denervation has been successfully applied in patients with resistant hypertension and was associated with significant falls in blood pressure and renal protection in most studies performed. The focus of this review is the neural contribution to the control of renal and cardiovascular hemodynamics and renal function in the setting of hypertension and chronic kidney disease, as well as the specific roles of renal efferent and afferent nerves in this scenario and their utility as a therapeutic target.

  9. [Autonomic angiotensinergic fibres in the human heart with an efferent sympathetic cophenotype].

    Science.gov (United States)

    Bohlender, J; Nussberger, J; Tevaearai, H; Imboden, H

    2015-06-01

    The autonomic innervation of the heart consists of sympathetic and parasympathetic nerve fibres, and fibres of the intrinsic ganglionated plexus with noradrenaline and acytylcholine as principal neurotransmitters. The fibres co-release neuropeptides to modulate intracardiac neurotransmission by specific presynaptic and postsynaptic receptors. The coexpression of angiotensin II in sympathetic fibres of the human heart and its role are not known so far. Autopsy specimens of human hearts were studied (n=3; ventricles). Using immunocytological methods, cryostat sections were stained by a murine monoclonal antibody (4B3) directed against angiotensin II and co-stained by polyclonal antibodies against tyrosine hydroxylase, a catecholaminergic marker. Visualisation of the antibodies was by confocal light microscopy or laser scanning microscopy. Angiotensin II-positive autonomic fibres with and without a catecholaminergic cophenotype (hydroxylase-positive) were found in all parts of the human ventricles. In the epicardium, the fibres were grouped in larger bundles of up to 100 and more fibres. They followed the preformed anatomic septa and epicardial vessels towards the myocardium and endocardium where the bundles dissolved and the individual fibres spread between myocytes and within the endocardium. Generally, angiotensinergic fibres showed no synaptic enlargements or only a few if they were also catecholaminergic. The exclusively catechalominergic fibres were characterised by multiple beaded synapses. The autonomic innervation of the human heart contains angiotensinergic fibres with a sympathetic efferent phenotype and exclusively angiotensinergic fibers representing probably afferents. Angiotensinergic neurotransmission may modulate intracardiac sympathetic and parasympathetic activity and thereby influence cardiac and circulatory function. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  10. CAPON modulates neuronal calcium handling and cardiac sympathetic neurotransmission during dysautonomia in hypertension.

    Science.gov (United States)

    Lu, Chieh-Ju; Hao, Guoliang; Nikiforova, Natalia; Larsen, Hege E; Liu, Kun; Crabtree, Mark J; Li, Dan; Herring, Neil; Paterson, David J

    2015-06-01

    Genome-wide association studies implicate a variant in the neuronal nitric oxide synthase adaptor protein (CAPON) in electrocardiographic QT variation and sudden cardiac death. Interestingly, nitric oxide generated by neuronal NO synthase-1 reduces norepinephrine release; however, this pathway is downregulated in animal models of cardiovascular disease. Because sympathetic hyperactivity can trigger arrhythmia, is this neural phenotype linked to CAPON dysregulation? We hypothesized that CAPON resides in cardiac sympathetic neurons and is a part of the prediseased neuronal phenotype that modulates calcium handling and neurotransmission in dysautonomia. CAPON expression was significantly reduced in the stellate ganglia of spontaneously hypertensive rats before the development of hypertension compared with age-matched Wistar-Kyoto rats. The neuronal calcium current (ICa; n=8) and intracellular calcium transient ([Ca(2+)]i; n=16) were significantly larger in the spontaneously hypertensive rat than in Wistar-Kyoto rat (P<0.05). A novel noradrenergic specific vector (Ad.PRSx8-mCherry/CAPON) significantly upregulated CAPON expression, NO synthase-1 activity, and cGMP in spontaneously hypertensive rat neurons without altering NO synthase-1 levels. Neuronal ICa and [Ca(2+)]i were significantly reduced after CAPON transduction compared with the empty vector. In addition, Ad.PRSx8-mCherry/CAPON also reduced (3)H-norepinephrine release from spontaneously hypertensive rat atria (n=7). NO synthase-1 inhibition (AAAN, 10 μmol/L; n=6) reversed these effects compared with the empty virus alone. In conclusion, targeted upregulation of CAPON decreases cardiac sympathetic hyperactivity. Moreover, dysregulation of this adaptor protein in sympathetic neurons might further amplify the negative cardiac electrophysiological properties seen with CAPON mutations. © 2015 American Heart Association, Inc.

  11. Comparison of sympathetic nerve responses to neck and forearm isometric exercise

    Science.gov (United States)

    Steele, S. L. Jr; Ray, C. A.

    2000-01-01

    PURPOSE: Although the autonomic and cardiovascular responses to arm and leg exercise have been studied, the sympathetic adjustments to exercise of the neck have not. The purpose of the present study was twofold: 1) to determine sympathetic and cardiovascular responses to isometric contractions of the neck extensors and 2) to compare sympathetic and cardiovascular responses to isometric exercise of the neck and forearm. METHODS: Muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate were measured in nine healthy subjects while performing isometric neck extension (INE) and isometric handgrip (IHG) in the prone position. After a 3-min baseline period, subjects performed three intensities of INE for 2.5 min each: 1) unloaded (supporting head alone), 2) 10% maximal voluntary contraction (MVC), and 3) 30% MVC, then subjects performed two intensities (10% and 30% MVC) of IHG for 2.5 min. RESULTS: Supporting the head by itself did not significantly change any of the variables. During [NE, MAP significantly increased by 10 +/- 2 and 31 +/- 4 mm Hg and MSNA increased by 67 +/- 46 and 168 +/- 36 units/30 s for 10% and 30% MVC, respectively. IHG and INE evoked similar responses at 10% MVC, but IHG elicited higher peak MAP and MSNA at 30% MVC (37 +/- 7 mm Hg (P INE can elicit marked increases in MSNA and cardiovascular responses but that it evokes lower peak responses as compared to IHG. We speculate that possible differences in muscle fiber type composition, muscle mass, and/or muscle architecture of the neck and forearm are responsible for these differences in peak responses.

  12. Sympathetic neuron-associated macrophages contribute to obesity by importing and metabolizing norepinephrine.

    Science.gov (United States)

    Pirzgalska, Roksana M; Seixas, Elsa; Seidman, Jason S; Link, Verena M; Sánchez, Noelia Martínez; Mahú, Inês; Mendes, Raquel; Gres, Vitka; Kubasova, Nadiya; Morris, Imogen; Arús, Bernardo A; Larabee, Chelsea M; Vasques, Miguel; Tortosa, Francisco; Sousa, Ana L; Anandan, Sathyavathy; Tranfield, Erin; Hahn, Maureen K; Iannacone, Matteo; Spann, Nathanael J; Glass, Christopher K; Domingos, Ana I

    2017-11-01

    The cellular mechanism(s) linking macrophages to norepinephrine (NE)-mediated regulation of thermogenesis have been a topic of debate. Here we identify sympathetic neuron-associated macrophages (SAMs) as a population of cells that mediate clearance of NE via expression of solute carrier family 6 member 2 (SLC6A2), an NE transporter, and monoamine oxidase A (MAOA), a degradation enzyme. Optogenetic activation of the sympathetic nervous system (SNS) upregulates NE uptake by SAMs and shifts the SAM profile to a more proinflammatory state. NE uptake by SAMs is prevented by genetic deletion of Slc6a2 or inhibition of the encoded transporter. We also observed an increased proportion of SAMs in the SNS of two mouse models of obesity. Genetic ablation of Slc6a2 in SAMs increases brown adipose tissue (BAT) content, causes browning of white fat, increases thermogenesis, and leads to substantial and sustained weight loss in obese mice. We further show that this pathway is conserved, as human sympathetic ganglia also contain SAMs expressing the analogous molecular machinery for NE clearance, which thus constitutes a potential target for obesity treatment.

  13. Three-phase bone studies in hemiplegia with reflex sympathetic dystrophy and the effect of disuse

    Energy Technology Data Exchange (ETDEWEB)

    Greyson, N.D.; Tepperman, P.S.

    1984-04-01

    Eighty-five patients with cerebral vascular accidents were assessed with three-phase bone scintigraphy of the hands and with whole-body delayed bone imaging. Nine patients (10%) had normal three-phase bone images. Fifty-five patients (65%) showed decreased blood flow and blood-pool images of the hands and wrists with normal delayed bone scintigrams, indicating the effect of paralysis or disuse. Twenty-one patients (25%) had diffuse increased uptake with periarticular accentuation, felt to be bone-scintigraphic evidence of reflex sympathetic dystrophy of the hands and wrists; in two patients this occurred before its clinical appearance. Thriteen of the 21 reflex sympathetic dystrophy syndromes (RDS)-involved limbs (62%) had increased blood flow, whereas 8 (38%) had decreased flow. Gross limb blood flow appears to be related to the degree of muscle activity, but flow may be altered by the presence of sympathetic changes. A possible dissociation between whole-limb flow and bone blood flow in paralyzed limbs involved with RDS is discussed.

  14. Sympathetic Neurotransmitters and Tumor Angiogenesis—Link between Stress and Cancer Progression

    Directory of Open Access Journals (Sweden)

    Jason Tilan

    2010-01-01

    Full Text Available Recent evidence supports a longstanding hypothesis that chronic stress can influence tumor growth and progression. It has been shown that sympathetic neurotransmitters, such as catecholamines and neuropeptides, can affect both cancer cell growth and tumor vascularization. Depending on neurotransmitter and type of tumor, these effects can be both stimulatory and inhibitory. Norepinephrine (NE and epinephrine (E are potent stimulators of vascularization, acting both by inducing the release of angiogenic factors from tumor cells and directly on endothelial cell (EC functions. As a result, activation of the adrenergic system increases growth of various types of tumors and has been shown to mediate stress-induced augmentation of tumor progression. Dopamine (DA, on the other hand, interferes with VEGF signaling in endothelial cells, blocks its angiogenic functions and inhibits tumor growth. Another sympathetic neurotransmitter coreleased with NE, neuropeptide Y (NPY, directly stimulates angiogenesis. However, proangiogenic actions of NPY can be altered by its direct effect on tumor cell proliferation and survival. In consequence, NPY can either stimulate or inhibit tumor growth, depending on tumor type. Hence, sympathetic neurotransmitters are powerful modulators of tumor growth and can become new targets in cancer therapy.

  15. Sympathetic mechanisms in diet-induced thermogenesis: modification by ciclazindol and anorectic drugs.

    OpenAIRE

    Rothwell, N. J.; Stock, M. J.; Wyllie, M. G.

    1981-01-01

    1 The sympathetic noradrenergic activation of brown adipose tissue and the biochemical mechanisms involved in diet-induced thermogenesis were studied in rats. 2 A close correlation was found between brown adipose tissue Na+, K+-adenosinetriphosphatase (Na+, K+-ATPase) activity in vitro and in vivo measurements of resting oxygen consumption (VO2). The effects of noradrenaline on in vitro NA+, K+-ATPase activity in brown adipose tissue and in vivo VO2 could be mimicked by a variety of agents. T...

  16. Sympathetic cooling of ytterbium with rubidium

    International Nuclear Information System (INIS)

    Tassy, S.

    2007-01-01

    Within the scope of this thesis, a mixture of ultracold ytterbium and rubidium atoms was experimentally realized and investigated. For these experiments, a novel trap geometry was developed which allows simultaneous trapping and cooling of diamagnetic and paramagnetic atomic species. The main focus was put on the investigation of the interspecies scattering properties, where sympathetic cooling of ytterbium through elastic collisions with rubidium could be demonstrated. In addition, the interspecies scattering length could be determined. In the current configuration the combined trap allows the preparation of up to 2.10 5 atoms of 170 Yb, 171 Yb, 172 Yb, 174 Yb or 176 Yb at a temperature of 40..60 μK and a density in the range of 10 12 cm -3 , and of about 10 7 87 Rb atoms at a temperature of 25 μK and a density in the range of 5.10 11 cm -3 . Detailed studies of the thermalization of bosonic 170 Yb, 172 Yb, 174 Yb and 176 Yb and of fermionic 171 Yb each with 87 Rb were performed under varying experimental conditions. The deduced total scattering cross section was clearly found to increase with higher mass of the ytterbium isotope. In general, a mass scaling of the scattering properties is in agreement with theoretical models and former experimental work. With the assumption of pure s-wave scattering, which is approximately fulfilled for the given experimental parameters, the interspecies scattering length could be derived from the measured thermalization data and was found to be (in units of the Bohr radius a 0 ): 170 Yb- 87 Rb:(18 +12 -4 )a 0 , 171 Yb- 87 Rb:(25 +14 -7 )a 0 , 172 Yb- 87 Rb:(33 +23 -7 )a 0 , 174 Yb- 87 Rb:(83 +89 -25 )a 0 , 176 Yb- 87 Rb:(127 +245 -45 )a 0 . (orig./HSI)

  17. Bisphosphonate therapy of reflex sympathetic dystrophy syndrome

    Science.gov (United States)

    Adami, S; Fossaluzza, V; Gatti, D; Fracassi, E; Braga, V

    1997-01-01

    OBJECTIVE—The reflex sympathetic dystrophy syndrome (RSDS) is a painful limb disorder, for which a consistently effective treatment has not yet been identified. The disease is associated with increased bone resorption and patchy osteoporosis, which might benefit from treatment with bisphosphonates, powerful inhibitors of bone resorption.
METHODS—Twenty patients with RSDS of foot and hand, were randomly assigned to blind administration of either alendronate intravenously (Istituto Gentili, Pisa, Italy) 7.5 mg dissolved in 250 ml saline solution or placebo saline infusions daily for three days. Two weeks later all patients had an identical treatment course with open labelled alendronate (7.5 mg/day for three days), independent from the results of the first blind treatment.
RESULTS—In the patients treated with blind alendronate the diminution in spontaneous pain, tenderness, and swelling (circumference of the affected limb) and the improvement in motion were significantly different from baseline (p<0.001), from those observed within the first two weeks in the control group (p<0.01), and from week 2 to week 4 (p<0.01). In the patients given blind placebo infusions no relevant symptomatic changes were observed after the first two weeks of follow up, but they responded to the open alendronate therapy given afterwards. In 12 patients with RSDS of the hand the ultradistal bone mineral content (BMC) of the affected arm was considerably lower than that of the controlateral arm (mean (SD)) (426(82) mg/cm versus 688(49)). Six weeks after the beginning of the trial BMC rose by 77(12) mg/cm (p<0.001) in the affected arm, but it did not change in the controlateral.
CONCLUSIONS—These results indicate that bisphosphonates should be considered for the treatment of RSDS, producing consistent and rapid remission of the disease.

 PMID:9135227

  18. Detachable glass microelectrodes for recording action potentials in active moving organs.

    Science.gov (United States)

    Barbic, Mladen; Moreno, Angel; Harris, Tim D; Kay, Matthew W

    2017-06-01

    Here, we describe new detachable floating glass micropipette electrode devices that provide targeted action potential recordings in active moving organs without requiring constant mechanical constraint or pharmacological inhibition of tissue motion. The technology is based on the concept of a glass micropipette electrode that is held firmly during cell targeting and intracellular insertion, after which a 100-µg glass microelectrode, a "microdevice," is gently released to remain within the moving organ. The microdevices provide long-term recordings of action potentials, even during millimeter-scale movement of tissue in which the device is embedded. We demonstrate two different glass micropipette electrode holding and detachment designs appropriate for the heart (sharp glass microdevices for cardiac myocytes in rats, guinea pigs, and humans) and the brain (patch glass microdevices for neurons in rats). We explain how microdevices enable measurements of multiple cells within a moving organ that are typically difficult with other technologies. Using sharp microdevices, action potential duration was monitored continuously for 15 min in unconstrained perfused hearts during global ischemia-reperfusion, providing beat-to-beat measurements of changes in action potential duration. Action potentials from neurons in the hippocampus of anesthetized rats were measured with patch microdevices, which provided stable base potentials during long-term recordings. Our results demonstrate that detachable microdevices are an elegant and robust tool to record electrical activity with high temporal resolution and cellular level localization without disturbing the physiological working conditions of the organ. NEW & NOTEWORTHY Cellular action potential measurements within tissue using glass micropipette electrodes usually require tissue immobilization, potentially influencing the physiological relevance of the measurement. Here, we addressed this limitation with novel 100-µg detachable

  19. Sympathetic pain? A role of poor parasympathetic nervous system engagement in vicarious pain states.

    Science.gov (United States)

    Nazarewicz, Julia; Verdejo-Garcia, Antonio; Giummarra, Melita J

    2015-11-01

    This study investigated the psychophysiological correlates of the subjective experience of vicarious pain; that is, a spontaneous experience of pain when seeing another in pain. Forty-nine healthy, otherwise pain-free individuals aged 18-55 years completed empathy and anxiety questionnaires and were classified into three groups: vicarious responders with high anxiety (n = 11), vicarious responders with low anxiety (n = 22), and nonresponders (n = 16). Electrophysiological recordings of heart rate variability (HRV) during paced breathing and cognitive stress (serial sevens task) were completed before participants viewed short videos of athletes in states of pain or happiness, taken from Australian League Football matches. Change in beats per minute, relative to neutral scenes, were analyzed for the first 4 s after onset of the painful or happy event. Anxious responders had lower HF-HRV than both other groups, implicating poor parasympathetic regulation specific to states of stress. Both vicarious responder groups had elevated HR at the event onset, regardless of valence. After viewing painful injuries, nonanxious vicarious responders showed sustained HR over time, anxious responders showed HR acceleration with a peak at 3 s after the injury onset, and nonresponders showed a pattern of marked HR deceleration. These findings suggest that vicarious pain in anxious responders is associated with poorly regulated sympathetic arousal via insufficient inhibitory parasympathetic activity, whereas nonanxious persons show sustained arousal. Clearly, multiple mechanisms in the central and peripheral nervous system must play a role in vicarious pain states, and the different manifestations are likely to lead to very different behavioral consequences. © 2015 Society for Psychophysiological Research.

  20. High resistivity silicon active pixel sensors for recording data from STEM

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.; De Geronimo, G.; Li, Z.; O' Connor, P.; Radeka, V.; Rehak, P. E-mail: rehak2@bnl.gov; Smith, G.C.; Wall, J.S.; Yu, B

    2003-10-11

    An X-ray Active Matrix Pixel Sensor (XAMPS) for recording Data from the Scanning Transmission Electron Microscope (STEM) was designed, produced and tested. The reason for measuring scattering angle of all STEM electrons is given together with the requirement on the performance of the XAMPS. Principles of the measurement of the number of STEM electrons scattered in a particular direction are summarized. Results of tests performed on a produced detector are described and the problem with the formation of an insulation layer between silicon and aluminum is identified. A change in the design of the pixel is proposed which results in a fully functioning XAMPS even with the insulation layer present.

  1. [Developmental changes of neurotransmitter properties in sympathetic neurons].

    Science.gov (United States)

    Masliukov, P M; Emanuilov, A I; Nozdrachev, A D

    2016-01-01

    Sympathetic ganglia consist of neurochemically and functionally distinct populations of neurons, characterized by a specific projection pattern and a set of neutransmitters including classical mediators (catecholamines and acetylcholine), neuropeptides and small molecules such as NO, H2S, CO. The majority of the principal ganglionic sympathetic neurons is noradrenergic and expresses tyrosine hydroxylase (TH), i.e., a key enzyme in catecholamine synthesis. In mammals, two third of catecholaminergic neurons also co-localizes neuropeptide Y. A small number of ganglionic sympathetic neurons contains enzyme of acetylcholine synthesis and some neuropeptides, such as somatostatin, vasoactive intestinal (poly)peptide (VIP), calcitonin gene-related peptide (CGRP). Acetylcholine-containing sympathetic neurons in most cases colocalize VIP and/or CGRP. Phenotype of autonomic neurons is regulated by both target-independent and target-dependent mechanisms. The most of transmitters are expressed during embryogenesis. TH appears during embryonic development and the percentage of TH-positive neurons remains virtually identical during ontogenesis. After birth, cholinergic neurons exhibit a noradrenergic phenotype. Expression of different neuropeptides changes in pre- and postnatal development. Neurotransmitter expression in sympathetic neurons is influenced by growth factor signaling via innervated target tissues. Multiple growth factors including bone morphogenetic proteins, neurotrophins, glial cell line-derived neurotrophic factor family ligands and neuropoietic cytokines play instructive role at different stages of neurotransmitter development.

  2. [MRI symptomology in reflex sympathetic dystrophy of the foot].

    Science.gov (United States)

    Darbois, H; Boyer, B; Dubayle, P; Lechevalier, D; David, H; Aït-Ameur, A

    1999-08-01

    To describe the MRI findings of reflex sympathetic dystrophy of the foot and ankle. Retrospective study of 50 patients with reflex sympathetic dystrophy of the foot (5 with the cold form, and 45 with the warm form) diagnosed based on clinical and scintigraphic findings. All patients underwent MR imaging. The MRI findings were correlated with the clinical and scintigraphic findings. Patients with the cold form of reflex sympathetic dystrophy had no abnormality of signal at MR imaging. All patients with the warm from of reflex sympathetic dystrophy showed periarticular marrow edema at MR, typically involving more than one bone (mean of 4). Other findings were inconstant: soft tissue edema, joint effusion, and rarely, subchondral band of low T1W signal intensity of unclear etiology. MR imaging, including fat-suppressed T2W or STIR images and noncontrast T1W images, is helpful in patients with the warm or acute form of reflex sympathetic dystrophy of the foot. In patients with the cold form, MR imaging is helpful to exclude another underlying etiology for the symptoms and identify patients with the warm form of the process.

  3. Increased vascular sympathetic modulation in mice with Mas receptor deficiency

    Science.gov (United States)

    Rabello Casali, Karina; Ravizzoni Dartora, Daniela; Moura, Marina; Bertagnolli, Mariane; Bader, Michael; Haibara, Andrea; Alenina, Natalia; Irigoyen, Maria Claudia; Santos, Robson A

    2016-01-01

    Introduction: The angiotensin-converting enzyme 2 (ACE2)/angiotensin (Ang)-(1–7)/Mas axis could modulate the heart rate (HR) and blood pressure variabilities (BPV) which are important predictors of cardiovascular risk and provide information about the autonomic modulation of the cardiovascular system. Therefore we investigated the effect of Mas deficiency on autonomic modulation in wild type and Mas-knockout (KO) mice. Methods: Blood pressure was recorded at high sample rate (4000 Hz). Stationary sequences of 200–250 beats were randomly chosen. Frequency domain analysis of HR and BPV was performed with an autoregressive algorithm on the pulse interval sequences and on respective systolic sequences. Results: The KO group presented an increase of systolic arterial pressure (SAP; 127.26±11.20 vs 135.07±6.98 mmHg), BPV (3.54±1.54 vs 5.87±2.12 mmHg2), and low-frequency component of systolic BPV (0.12±0.11 vs 0.47±0.34 mmHg2). Conclusions: The deletion of Mas receptor is associated with an increase of SAP and with an increased BPV, indicating alterations in autonomic control. Increase of sympathetic vascular modulation in absence of Mas evidences the important role of Ang-(1–7)/Mas on cardiovascular regulation. Moreover, the absence of significant changes in HR and HRV can indicate an adaptation of autonomic cardiac balance. Our results suggest that the Ang-(1–7)/Mas axis seems more important in autonomic modulation of arterial pressure than HR. PMID:27080540

  4. Advances in recording scattered light changes in crustacean nerve with electrical activation

    Energy Technology Data Exchange (ETDEWEB)

    Carter, K. M. (Kathleen M.); Rector, D. M. (David M.); Martinez, A. T. (Anne T.); Guerra, F. M. (Francisco M.); George, J. S. (John S.)

    2002-01-01

    We investigated optical changes associated with crustacean nerve stimulation using birefringent and large angle scattered light. Improved detection schemes disclosed high temporal structure of the optical signals and allowed further investigations of biophysical mechanisms responsible for such changes. Most studies of physiological activity in neuronal tissue use techniques that measure the electrical behavior or ionic permeability of the nerve, such as voltage or ion sensitive dyes injected into cells, or invasive electric recording apparatus. While these techniques provide high resolution, they are detrimental to tissue and do not easily lend themselves to clinical applications in humans. Electrical and chemical components of neural excitation evoke physical responses observed through changes in scattered and absorbed light. This method is suited for in-vivo applications. Intrinsic optical changes have shown themselves to be multifaceted in nature and point to several different physiological processes that occur with different time courses during neural excitation. Fast changes occur concomitantly with electrical events, and slow changes parallel metabolic events including changes in blood flow and oxygenation. Previous experiments with isolated crustacean nerves have been used to study the biophysical mechanisms of fast optical changes. However, they have been confounded by multiple superimposed action potentials which make it difficult to discriminate the temporal signatures of individual optical responses. Often many averages were needed to adequately resolve the signal. More recently, optical signals have been observed in single trials. Initially large angle scattering measurements were used to record these events with much of the signal coming from cellular swelling associated with water influx during activation. By exploiting the birefringent properties derived from the molecular stiucture of nerve membranes, signals appear larger with a greater contrast

  5. Thermal fluctuations in perpendicular recording media: New methodology for estimation of activation moment

    International Nuclear Information System (INIS)

    Mamiya, H; Oba, Y; Ohnuma, M; Hagiya, H; Oku, T; Suzuki, J; Yokoyama, M; Nishihara, Y; Katayama, T; Awano, H; Koda, T

    2011-01-01

    In nanoparticulate films with perpendicular magnetic anisotropy, a large demagnetizing field almost compensates for the experimentally designed change in the magnetic field applied parallel to the film normal. We propose a new method based on field-cycling to eliminate the uncertainty in the demagnetizing response from the analysis of the activation volume of the reversal or magnetic activation moment in such films. In this method, the applied field induced variation in the magnetic relaxation rate is measured before the effect of the demagnetizing field becomes dominant. We also discuss an analogical thermal-cycling method to clarify the temperature dependence of the barrier height for magnetization reversal in a magnetic field. We apply these methods to a Co 74 Pt 16 Cr 10 -SiO 2 nanoparticulate film as an example. The results demonstrate that these methods are useful for studying thermal fluctuations in perpendicular recording media.

  6. Antiallodynic Effect of Pregabalin in Rat Models of Sympathetically Maintained and Sympathetic Independent Neuropathic Pain

    Science.gov (United States)

    Han, Dong Woo; Kweon, Tae Dong; Lee, Jong Seok

    2007-01-01

    Pregabalin binds to the voltage-dependent calcium channel α2δ subunit and modulates the release of neurotransmitters, resulting in analgesic effects on neuropathic pain. Neuropathic pain has both sympathetically maintained pain (SMP) and sympathetic independent pain (SIP) components. We studied the antiallodynic effects of pregabalin on tactile allodynia (TA) and cold allodynia (CA) in SMP-and SIP-dominant neuropathic pain models. Allodynia was induced by ligation of the L5 & L6 spinal nerves (SMP model) or by transection of the tibial and sural nerves (SIP model) in rats. For intrathecal drug administration, a PE-10 catheter was implanted through the atlantooccipital membrane to the lumbar enlargement. Pregabalin was administered either intraperitoneally (IP) or intrathecally (IT) and dosed up incrementally until an antiallodynic effect without sedation or motor impairment was apparent. TA was assessed using von Frey filaments, and CA was assessed using acetone drops. IP-administered pregabalin dose-dependently attenuated TA in both models and CA in the SMP model, but not CA in the SIP model. IT-administered pregabalin dose-dependently attenuated both TA and CA in both models. However, the dose response curve of IT-administered pregabalin in SMP was shifted to left from that of SIP and the ED50 of IT-administered pregabalin for CA in SMP was about 900 times less than that in SIP. These findings suggest that pregabalin exerts its antiallodynic effect mainly by acting at the spinal cord, and that IT-administered pregabalin has more potent antiallodynic effects in SMP. The α2δ subunit might be less involved in the CA in SIP. PMID:17326244

  7. Glial cell line-derived neurotrophic factor (GDNF) enhances sympathetic neurite growth in rat hearts at early developmental stages

    NARCIS (Netherlands)

    Miwa, Keiko; Lee, Jong-Kook; Takagishi, Yoshiko; Opthof, Tobias; Fu, Xianming; Kodama, Itsuo

    2010-01-01

    Molecular signaling of sympathetic innervation of myocardium is an unresolved issue. The purpose of this study was to investigate the effect of neurotrophic factors on sympathetic neurite growth towards cardiomyocytes. Cardiomyocytes (CMs) and sympathetic neurons (SNs) were isolated from neonatal

  8. Image-guided recording system for spatial and temporal mapping of neuronal activities in brain slice.

    Science.gov (United States)

    Choi, Geonho; Lee, Jeonghyeon; Kim, Hyeongeun; Jang, Jaemyung; Im, Changkyun; Jeon, Nooli; Jung, Woonggyu

    2018-03-01

    In this study, we introduce the novel image-guided recording system (IGRS) for efficient interpretation of neuronal activities in the brain slice. IGRS is designed to combine microelectrode array (MEA) and optical coherence tomography at the customized upright microscope. It allows to record multi-site neuronal signals and image of the volumetric brain anatomy in a single body configuration. For convenient interconnection between a brain image and neuronal signals, we developed the automatic mapping protocol that enables us to project acquired neuronal signals on a brain image. To evaluate the performance of IGRS, hippocampal signals of the brain slice were monitored, and corresponding with two-dimensional neuronal maps were successfully reconstructed. Our results indicated that IGRS and mapping protocol can provide the intuitive information regarding long-term and multi-sites neuronal signals. In particular, the temporal and spatial mapping capability of neuronal signals would be a very promising tool to observe and analyze the massive neuronal activity and connectivity in MEA-based electrophysiological studies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. A multichannel integrated circuit for electrical recording of neural activity, with independent channel programmability.

    Science.gov (United States)

    Mora Lopez, Carolina; Prodanov, Dimiter; Braeken, Dries; Gligorijevic, Ivan; Eberle, Wolfgang; Bartic, Carmen; Puers, Robert; Gielen, Georges

    2012-04-01

    Since a few decades, micro-fabricated neural probes are being used, together with microelectronic interfaces, to get more insight in the activity of neuronal networks. The need for higher temporal and spatial recording resolutions imposes new challenges on the design of integrated neural interfaces with respect to power consumption, data handling and versatility. In this paper, we present an integrated acquisition system for in vitro and in vivo recording of neural activity. The ASIC consists of 16 low-noise, fully-differential input channels with independent programmability of its amplification (from 100 to 6000 V/V) and filtering (1-6000 Hz range) capabilities. Each channel is AC-coupled and implements a fourth-order band-pass filter in order to steeply attenuate out-of-band noise and DC input offsets. The system achieves an input-referred noise density of 37 nV/√Hz, a NEF of 5.1, a CMRR > 60 dB, a THD noise ratios.

  10. The release of sympathetic neurotransmitters is impaired in aged rats after an inflammatory stimulus. A possible link between cytokine production and sympathetic transmission

    Science.gov (United States)

    Donoso, Verónica; Gomez, Christian R.; Orriantia, Miguel Ángel; Pérez, Viviana; Torres, Claudio; Coddou, Claudio; Nelson, Pablo; Maisey, Kevin; Morales, Bernardo; Fernandez, Ricardo; Imarai, Mónica; Huidobro-Toro, Juan Pablo; Sierra, Felipe; Acuña-Castillo, Claudio

    2009-01-01

    Aging results in a general decline in the response to external insults, including acute inflammatory challenges. In young animals, the inflammatory response requires activation of the sympathetic system, including neurotransmitters such as ATP, and catecholamines (epinephrine and norepinephrine). To test whether aging affects activation of this axis, and whether this in turn might affect cytokine release, we administered lipopolysaccharide (LPS) i.p. to adult, middle-aged and aged Fisher 344 rats (6, 15 and 23-month old, respectively) and evaluated the early (0–12 hours) serum levels of Neuropeptide-Y (NP-Y), ATP and vanillyl mandelic acid (VMA, as an indirect measurement of catecholamine levels). In addition, we evaluated the association between these factors and serum levels of the cytokines tumor necrosis factor-alpha (TNFα)3 and interleukin-10 (IL-10). Induction of both ATP and NP-Y was markedly reduced in the serum of aged animals, when compared to their younger counterparts, while induction of VMA was not affected by age. In spite of these changes, serum levels of TNFα and IL-10 were strongly hyper induced and delayed in aged rats. The results suggest that during aging there is a dysregulation in sympathetic neurotransmitter regulatory mechanisms, and this might play a role in the impairment of the inflammatory response. PMID:18973771

  11. [Reflex sympathetic dystrophy: description of a case with skin lesions].

    Science.gov (United States)

    Vergara, Aránzazu; Isarría, María J; Prado Sánchez-Caminero, María; Guerra, Aurora

    2005-10-01

    Reflex sympathetic dystrophy or algodystrophy is a poorly defined syndrome in which the patient develops pain disproportionate to the cause. It is included among the complex regional pain syndromes. The symptoms are triggered by some type of trauma, at times trivial, and consist of burning pain, edema, changes in skin color, alterations in vascularization, temperature changes, hyperhidrosis and skin disorders, which primarily consist of atrophic changes. Other less frequent cutaneous manifestations have been described in patients with this syndrome. These include papules, blisters, inflammatory lesions and reticulated hyperpigmentation. We discuss the case of a patient with reflex sympathetic dystrophy who presented with superficial ulcers on the affected limb, which mimicked dermatitis artefacta.

  12. Baroreflex dysfunction and augmented sympathetic nerve responses during mental stress in veterans with post-traumatic stress disorder.

    Science.gov (United States)

    Park, Jeanie; Marvar, Paul J; Liao, Peizhou; Kankam, Melanie L; Norrholm, Seth D; Downey, Ryan M; McCullough, S Ashley; Le, Ngoc-Anh; Rothbaum, Barbara O

    2017-07-15

    Patients with post-traumatic stress disorder (PTSD) are at a significantly higher risk of developing hypertension and cardiovascular disease. The mechanisms underlying this increased risk are not known. Studies have suggested that PTSD patients have an overactive sympathetic nervous system (SNS) that could contribute to cardiovascular risk; however, sympathetic function has not previously been rigorously evaluated in PTSD patients. Using direct measurements of sympathetic nerve activity and pharmacological manipulation of blood pressure, we show that veterans with PTSD have augmented SNS and haemodynamic reactivity during both combat-related and non-combat related mental stress, impaired sympathetic and cardiovagal baroreflex sensitivity, and increased inflammation. Identifying the mechanisms contributing to increased cardiovascular (CV) risk in PTSD will pave the way for developing interventions to improve sympathetic function and reduce CV risk in these patients. Post-traumatic stress disorder (PTSD) is associated with increased cardiovascular (CV) risk. We tested the hypothesis that PTSD patients have augmented sympathetic nervous system (SNS) and haemodynamic reactivity during mental stress, as well as impaired arterial baroreflex sensitivity (BRS). Fourteen otherwise healthy Veterans with combat-related PTSD were compared with 14 matched Controls without PTSD.  Muscle sympathetic nerve activity (MSNA), continuous blood pressure (BP) and electrocardiography were measured at baseline, as well as during two types of mental stress:  combat-related mental stress using virtual reality combat exposure (VRCE) and non-combat related stress using mental arithmetic (MA). A cold pressor test (CPT) was administered for comparison. BRS was tested using pharmacological manipulation of BP via the Modified Oxford technique at rest and during VRCE. Blood samples were analysed for inflammatory biomarkers. Baseline characteristics, MSNA and haemodynamics were similar between

  13. Intrathecal Intermittent Orexin-A Causes Sympathetic Long-Term Facilitation and Sensitizes the Peripheral Chemoreceptor Response to Hypoxia in Rats.

    Science.gov (United States)

    Kim, Seung Jae; Pilowsky, Paul M; Farnham, Melissa M J

    2016-09-01

    Intermittent hypoxia causes a persistent increase in sympathetic nerve activity (SNA), which progresses to hypertension in conditions such as obstructive sleep apnea. Orexins (A and B) are hypothalamic neurotransmitters with arousal-promoting and sympathoexcitatory effects. We investigated whether the sustained elevation of SNA, termed sympathetic long-term facilitation, after acute intermittent hypoxia (AIH) is caused by endogenous orexin acting on spinal sympathetic preganglionic neurons. The role of orexin in the increased SNA response to AIH was investigated in urethane-anesthetized, vagotomized, and artificially ventilated Sprague-Dawley rats (n = 58). A spinally infused subthreshold dose of orexin-A (intermittent; 0.1 nmol × 10) produced long-term enhancement in SNA (41.4% ± 6.9%) from baseline. This phenomenon was not produced by the same dose of orexin-A administered as a bolus intrathecal infusion (1 nmol; 7.3% ± 2.3%). The dual orexin receptor blocker, Almorexant, attenuated the effect of sympathetic long-term facilitation generated by intermittent orexin-A (20.7% ± 4.5% for Almorexant at 30 mg∙kg(-1) and 18.5% ± 1.2% for 75 mg∙kg(-1)), but not in AIH. The peripheral chemoreflex sympathoexcitatory response to hypoxia was greatly enhanced by intermittent orexin-A and AIH. In both cases, the sympathetic chemoreflex sensitization was reduced by Almorexant. Taken together, spinally acting orexin-A is mechanistically sufficient to evoke sympathetic long-term facilitation. However, AIH-induced sympathetic long-term facilitation appears to rely on mechanisms that are independent of orexin neurotransmission. Our findings further reveal that the activation of spinal orexin receptors is critical to enhance peripheral chemoreceptor responses to hypoxia after AIH. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  14. 24 CFR 1000.554 - Which agencies have right of access to the recipient's records relating to activities carried out...

    Science.gov (United States)

    2010-04-01

    ..., shall have the right of access to any pertinent books, documents, papers, or other records of recipients... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Which agencies have right of access... agencies have right of access to the recipient's records relating to activities carried out under NAHASDA...

  15. Cardiorenal axis and arrhythmias: Will renal sympathetic denervation provide additive value to the therapeutic arsenal?

    NARCIS (Netherlands)

    van Brussel, Peter M.; Lieve, Krystien V. V.; de Winter, Robbert J.; Wilde, Arthur A. M.

    2015-01-01

    Disruption of sympathetic tone may result in the occurrence or maintenance of cardiac arrhythmias. Multiple arrhythmic therapies that intervene by influencing cardiac sympathetic tone are common in clinical practice. These vary from pharmaceutical (β-blockers, angiotensin-converting enzyme

  16. Correlations between histology and neuronal activity recorded by microelectrodes implanted chronically in the cerebral cortex

    Science.gov (United States)

    McCreery, Douglas; Cogan, Stuart; Kane, Sheryl; Pikov, Victor

    2016-06-01

    Objective. To quantify relations between the neuronal activity recorded with chronically-implanted intracortical microelectrodes and the histology of the surrounding tissue, using radial distance from the tip sites and time after array implantation as parameters. Approach. ‘Utah’-type intracortical microelectrode arrays were implanted into cats’ sensorimotor cortex for 275-364 days. The brain tissue around the implants was immuno-stained for the neuronal marker NeuN and for the astrocyte marker GFAP. Pearson’s product-moment correlations were used to quantify the relations between these markers and the amplitudes of the recorded neuronal action potentials (APs) and their signal-to-noise ratios (S/N). Main results. S/N was more stable over post-implant time than was AP amplitude, but its increased correlation with neuronal density after many months indicates ongoing loss of neurons around the microelectrodes. S/N was correlated with neuron density out to at least 140 μm from the microelectrodes, while AP amplitude was correlated with neuron density and GFAP density within ˜80 μm. Correlations between AP amplitude and histology markers (GFAP and NeuN density) were strongest immediately after implantation, while correlation between the neuron density and S/N was strongest near the time the animals were sacrificed. Unlike AP amplitude, there was no significant correlation between S/N and density of GFAP around the tip sites. Significance. Our findings indicate an evolving interaction between changes in the tissue surrounding the microelectrodes and the microelectrode’s electrical properties. Ongoing loss of neurons around recording microelectrodes, and the interactions between their delayed electrical deterioration and early tissue scarring around the tips appear to pose the greatest threats to the microelectrodes’ long-term functionality.

  17. New Evaluation of the Electronically Activated Recorder (EAR: Obtrusiveness, Compliance, and Participant Self-selection Effects

    Directory of Open Access Journals (Sweden)

    Joseph H. Manson

    2017-04-01

    Full Text Available The Electronically Activated Recorder (EAR is a method for collecting periodic brief audio snippets of participants’ daily lives using a portable recording device. The EAR can potentially intrude into people’s privacy, alter their natural behavior, and introduce self-selection biases greater than in other types of social science methods. Previous research (Mehl and Holleran, 2007, hereafter M&H has shown that participant non-compliance with, and perceived obtrusiveness of, an EAR protocol are both low. However, these questions have not been addressed in jurisdictions that require the consent of all parties to recording conversations. This EAR study required participants to wear a button bearing a microphone icon and the words “This conversation may be recorded” to comply with California’s all-party consent law. Results revealed self-reported obtrusiveness and non-compliance were actually lower in the present study than in the M&H study. Behaviorally assessed non-compliance did not differ between the two studies. Participants in the present study talked more about being in the study than participants in the M&H study, but such talk still comprised <2% of sampled conversations. Another potential problem with the EAR, participant self-selection bias, was addressed by comparing the EAR volunteers’ HEXACO personality dimensions to a non-volunteer sample drawn from the same student population. EAR volunteers were significantly and moderately higher in Conscientiousness, and lower in Emotionality, than non-volunteers. In conclusion, the EAR method can be successfully implemented in at least one all-party consent state (California. Interested researchers are encouraged to review this procedure with their own legal counsel.

  18. Using an electronic detonator system and expanded blast patterns to prevent sympathetic detonation at Powder River Basin coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Yang, R.; Fleetwood, K.; Haid, J. [Orica USA Inc., Watkins, CO (United States). Advanced Mining Solutions

    2005-07-01

    This paper describes a systematic approach to prevent cast blast holes from detonating sympathetically through the use of the electronic initiation and expanded blast patterns. In-situ measurements were recorded from pressure probes, velocity of detonation probes and near field accelerometers, along with digital images generated from a high speed CCD camera. Large diameter angled drill holes were also checked for any measurable amount of deviation by a cable type borehole measurement tool. The field measurements provided the scientific evidence, statistical data, and documentation necessary to develop a sound method or a 'road map' that would minimize and in some situations prevent the occurrence of blast hole sympathetic detonation. 2 refs., 3 figs.

  19. Multielectrode array recordings of bladder and perineal primary afferent activity from the sacral dorsal root ganglia

    Science.gov (United States)

    Bruns, Tim M.; Gaunt, Robert A.; Weber, Douglas J.

    2011-10-01

    The development of bladder and bowel neuroprostheses may benefit from the use of sensory feedback. We evaluated the use of high-density penetrating microelectrode arrays in sacral dorsal root ganglia (DRG) for recording bladder and perineal afferent activity. Arrays were inserted in S1 and S2 DRG in three anesthetized cats. Neural signals were recorded while the bladder volume was modulated and mechanical stimuli were applied to the perineal region. In two experiments, 48 units were observed that tracked bladder pressure with their firing rates (79% from S2). At least 50 additional units in each of the three experiments (274 total; 60% from S2) had a significant change in their firing rates during one or more perineal stimulation trials. This study shows the feasibility of obtaining bladder-state information and other feedback signals from the pelvic region with a sacral DRG electrode interface located in a single level. This natural source of feedback would be valuable for providing closed-loop control of bladder or other pelvic neuroprostheses.

  20. First forensic records of termite activity on non-fossilized human bones in Brazil

    Directory of Open Access Journals (Sweden)

    R. A. Queiroz

    Full Text Available Abstract The aim of this study was to describe the first records of termite activity on non-fossilized human bones in Brazil. The cases reported in this study resulted from forensic analysis of six human skeletons found in northeastern Brazil between 2012 and 2014. Traces of tunnels and nests commonly produced by termites were found on several human bone surfaces as well as the specimens and characteristic signs of osteophagic activity. In four cases, the species were identified: Amitermes amifer Silvestri, 1901, Nasutitermes corniger (Motschulsky, 1855 (on two skeletons, and Microcerotermes indistinctus Mathews, 1977. In two other cases, the activity of termites on bone surfaces was evidenced by remains of nests and tunnels produced by these insects. At least in the samples of human remains available for this report, the number of termites collected was greater on bones found during autumn, the rainy season in the Northeast of Brazil. The human bones examined showed termites like insects with lots of strength at bone degradation, capable of continuing the process of decomposition of human remains even in completely skeletonized bodies.

  1. First forensic records of termite activity on non-fossilized human bones in Brazil.

    Science.gov (United States)

    Queiroz, R A; Soriano, E P; Carvalho, M V D; Caldas-Junior, A F; Souza, E H A; Coelho-Junior, L G T M; Campello, R I C; Almeida, A C; Farias, R C A P; Vasconcellos, A

    2016-07-25

    The aim of this study was to describe the first records of termite activity on non-fossilized human bones in Brazil. The cases reported in this study resulted from forensic analysis of six human skeletons found in northeastern Brazil between 2012 and 2014. Traces of tunnels and nests commonly produced by termites were found on several human bone surfaces as well as the spe