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Sample records for normotensive conscious rats

  1. The involvement of the central cholinergic system in the pressor and bradycardic effects of centrally administrated melittin in normotensive conscious rats.

    Science.gov (United States)

    Yalcin, Murat; Erturk, Melih

    2007-04-01

    Recently we demonstrated that centrally administrated melittin, a phospholipase A(2) (PLA(2)) activator, caused pressor and bradycardic effect in the normotensive conscious rats. In the current study we aimed to determine the mediation of central cholinergic system in the pressor and bradycardic effect of centrally administrated melittin. Studies were performed in normotensive male Sprague-Dawley rats. 1.5, 3.0 or 6.0microg/5.0microl doses of melittin were injected intracerebroventricularly (i.c.v.). Melittin caused dose- and time-dependent increases in mean arterial pressure (MAP) and decrease in heart rate (HR). In order to test the mediation of central cholinergic system on the pressor and bradycardic effect of melittin, the rats were pretreated with mecamylamine (50microg; i.c.v.), cholinergic nonselective nicotinic receptor antagonist, atropine sulfate (10microg; i.c.v.), a cholinergic nonselective muscarinic receptor antagonist, hemicholinium-3 (20microg; i.c.v.), a high affinity neuronal choline uptake inhibitor, methyllycaconitine (10 and 25microg; i.c.v.) or alpha-bungarotoxin (10 and 25microg; i.c.v.), selective antagonists of alpha-7 subtype nicotinic acetylcholine receptors (alpha7nAChRs), 15min prior to melittin (3.0microg) injection. Pretreatment with mecamylamine, hemicholinium-3, methyllycaconitine or alpha-bungarotoxin partially attenuated the pressor and bradicardia effect of elicited by melittin in the normotensive conscious rats whereas pretreatment with atropine had no effect. In conclusion, i.c.v. administration of melittin increases MAP and decreases HR in conscious rats. The activation of central nicotinic cholinergic receptors, predominantly alpha7nAChRs, partially acts as a mediator in the pressor responses to i.c.v. injection of melittin in the normotensive conscious rats. Moreover, decreased uptake of choline to the cholinergic terminals may consider that melittin activates central choline and acetylcholine release, as well.

  2. Patterns of blood pressure variability in normotensive and hypertensive rats

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; He, J; Wagner, A J

    1995-01-01

    We sought patterns in mean arterial pressure of normotensive rats and alterations in chronic hypertension. Pressure was recorded for 4-6 days by telemetry from conscious, unrestrained rats and sampled digitally at 3 Hz, using normotensive Sprague-Dawley rats, spontaneously hypertensive rats (SHR...... approximately 0.1 to 10 mHz the spectra were 1/f and without distinct peaks. The slopes were not significantly different among the groups and ranged from -1.03 to -1.61. At frequencies > 10 mHz, power continued to decrease but with a lower slope. A peak centered at approximately 100 mHz was present in both...... the day; less pronounced in 2K,1C; and not detectable in SHR. There are regular patterns of blood pressure fluctuations and specific modifications to the patterns by different forms of hypertension....

  3. Patterns of heart rate responses to hydralazine in normotensive and hypertensive rats.

    Science.gov (United States)

    Vidrio, H

    1996-01-01

    Hydralazine (H) induces hypotension accompanied by cardiac stimulation due to activation of the arterial baroreflex. Both clinical and experimental observations suggest, however, that in certain conditions H hypotension can be accompanied by unchanged or even depressed cardiac performance. The present study determined whether varying patterns of heart rate responses could be detected in large populations of conscious normotensive (n = 61) and renal hypertensive (n = 59) rats receiving a single dose of H. These patterns were compared with those of normotensive pentobarbital-anesthetized rats (n = 43). In the three groups, hypotension was accompanied by either tachycardia, unchanged heart rate or bradycardia. Tachycardia was found in 52% of normotensive conscious rats, in 51% of hypertensives and in only 14% of anesthetized animals. Heart rate did not change in 26, 35 and 23%, while bradycardia was detected in 22, 14 and 63%, respectively. These results were explained by postulating the initiation by H of two reflexes with opposite effects on heart rate: the arterial baroreflex producing tachycardia and a cardiac mechanoreceptor reflex producing bradycardia. These reactions would compete with each other, with results depending on their relative sensitivity in a given animal.

  4. Cardiovascular Effects of the Essential Oil of Croton argyrophylloides in Normotensive Rats: Role of the Autonomic Nervous System

    Science.gov (United States)

    Alves-Santos, Thayane Rebeca; de Siqueira, Rodrigo José Bezerra; Duarte, Gloria Pinto

    2016-01-01

    Cardiovascular effects of the essential oil of Croton argyrophylloides Muell. Arg. (EOCA) were investigated in normotensive rats. In saline-pretreated anesthetized or conscious rats, intravenous (i.v.) injection of the EOCA induced dose-dependent hypotension. Dose-dependent tachycardia was observed only in conscious rats. In anesthetized rats, cervical bivagotomy failed to enhance EOCA-induced hypotension but unmasked significant bradycardia. In conscious rats, i.v. pretreatment with methylatropine, but not with atenolol or L-NAME, reduced both hypotensive and tachycardiac responses to EOCA. However, hexamethonium pretreatment reverted the EOCA-induced tachycardia into significant bradycardia without affecting the hypotension. In aortic ring preparations precontracted with phenylephrine, EOCA induced a concentration-dependent relaxation that was significantly reduced by vascular endothelium removal and pretreatment with atropine, indomethacin, or glibenclamide but remained unaffected by pretreatment with L-NAME or TEA. It is concluded that i.v. treatment with EOAC decreased blood pressure probably through an active vascular relaxation rather than withdrawal of sympathetic tone. Muscarinic receptor stimulation, liberation of the endothelium-derived prostacyclin, and opening KATP channels are partially involved in the aortic relaxation induced by EOCA and in turn in the mediation of EOCA-induced hypotension. EOCA-induced tachycardia in conscious rats appears to be mediated reflexly through inhibition of vagal drive to the heart. PMID:27956919

  5. Trigeminovascular stimulation in conscious rats

    NARCIS (Netherlands)

    Kemper, RHA; Meijler, WJ; TerHorst, GJ

    1997-01-01

    INTRACISTERNAL infusion of capsaicin was used to induce intracranial trigeminovascular stimulation in conscious rats. Both behaviour and trigeminal nucleus caudalis c-fos expression were examined. Exploratory behaviour was dose-dependently reduced and different types of behaviours were induced with

  6. Hypotensive property of Chenopodium ambrosioides in anesthetized normotensive rats.

    Science.gov (United States)

    Assaidi, Asmae; Legssyer, Abdelkhaleq; Berrichi, Abdelbasset; Aziz, Mohammed; Mekhfi, Hassane; Bnouham, Mohammed; Ziyyat, Abderrahim

    2014-02-20

    The leaves of Chenopodium ambrosioides L. (Chenopodiaceae) are widely used in Moroccan traditional medicine to treat diabetes and hypertension. The goal of the present work is to investigate the hypotensive properties of different extract and fractions of the plant in anesthetized normotensive rats and to elucidate the mechanism underlying this effect. The hypotensive effect of aqueous extract (AqE) of the leaves of C. ambrosioides L., methanolic (MF), ethyl acetate (AcF), and aqueous (AqF) Soxhlet fractions, administrated intravenously, was evaluated in anesthetized rats. The recorded signals of blood pressure and heart rate were visualized and analyzed by using an acquisition card "National Instrument" and software Labview 6.1. Intravenous administration of AqE of the leaves of C. ambrosioides L. induces a dose-dependent hypotension. A similar effect was obtained with MF, AcF, and AqF. Atropine (1 mg/kg), used to block cholinergic system, significantly reduced the hypotensive response to MF and AcF suggesting the presence of the cholinomimetic-muscarinic components in these fractions. However, the blood pressure lowering effect of MF and AcF in rats pretreated with L-NAME 20 mg/kg was unchanged showing that the release of NO is not implicated in the hypotensive action of this plant. The present study demonstrates that extracts from leaves of C. ambrosioides induce hypotensive effect that may be partially associated with its cardiac effects. These results may partly explain the traditional use of leaves of C. ambrosioides L. for the treatment of disorders such as hypertension.

  7. The Diterpene Sclareol Vascular Effect in Normotensive and Hypertensive Rats.

    Science.gov (United States)

    Campos, Debora Ribeiro; Celotto, Andrea Carla; Albuquerque, Agnes Afrodite S; Ferreira, Luciana Garros; Monteiro, Ariadne Santana E Neves; Coelho, Eduardo Barbosa; Evora, Paulo Roberto Barbosa

    2017-06-29

    The diterpene Sclareol has antimicrobial action, cytotoxic and cytostatic effects and anti-tumor activities. However, researches on the cardiovascular system are scarce. This study was designed to investigate the mechanisms involved in the Sclareol cardiovascular effect in normotensive and hypertensive rats. The arterial hypertension was promoted using 2-kidneys 1-clip model in rats. The effect of sclareol on blood pressure was performed by using three dose (10, 20 and 40 mg/kg). Cumulative dose-response curves for Sclareol were determined for endothelium-intact and endothelium-denuded aortic rings in presence or absence of L-NAME and ODQ. The NOx levels were measure in the plasma sample. The Sclareol administration in vivo caused a significant reduction in blood pressure in both groups. In vitro the sclareol promoted relaxation in aorta, with endothelium, pre-contracted to Phe. The inhibitors of the nitric oxide synthase and soluble guanylate cyclase were as efficient as the removal of endothelium, in inhibiting the Sclareol-induced relaxation. Otherwise, it was no change of NOx. Also, for unknown reasons, the Sclareol is not selective for hypertensive animals. The diterpene Sclareol showed in vivo hypotensive and in-vitro vasodilator effects; The chemiluminescence plasmatic NO analysis showed no significant difference between groups and The Sclareol exhibit better effect on normotensive than hypertensive animals to reduce blood pressure. It is concluded that the diterpenes metabolites would be a promising source prototype for the development of new agents in the cardiovascular therapy. O diterpeno Esclareol tem ação antimicrobiana, efeitos citotóxicos e citostáticos e atividades antitumorais. No entanto, pesquisas sobre o sistema cardiovascular são escassas. Este estudo foi desenvolvido para investigar os mecanismos envolvidos no efeito cardiovascular de Esclareol em ratos normotensos e hipertensos. A hipertensão arterial foi promovida utilizando modelo de

  8. Spontaneously hypertensive rats have more orexin neurons in their medial hypothalamus than normotensive rats.

    Science.gov (United States)

    Clifford, Liam; Dampney, Bruno W; Carrive, Pascal

    2015-04-01

    What is the central question of this study? Blockade of orexin receptors reduces blood pressure in spontaneously hypertensive rats (SHRs) but not in normotensive Wistar-Kyoto (WKY) rats, suggesting that upregulation of orexin signalling underlies the hypertensive phenotype of the SHR. However, it is not known what causes this upregulation. What is the main finding and its importance? Using orexin immunolabelling, we show that SHRs have 20% more orexin neurons than normotensive WKY and Wistar rats in the medial hypothalamus, which is a good match to their blood pressure phenotype. In contrast, there is no such match for the orexin neurons of the lateral hypothalamus. Essential hypertension may be linked to an increase in orexin neurons in the medial hypothalamus. The neuropeptide orexin contributes to the regulation of blood pressure as part of its role in the control of arousal during wakefulness and motivated behaviour (including responses to psychological stress). Recent work shows that pharmacological blockade of orexin receptors reduces blood pressure in spontaneously hypertensive rats (SHRs) but not in normotensive Wistar-Kyoto (WKY) rats. It is not clear why orexin signalling is upregulated in the SHR, but one possibility is that these animals have more orexin neurons than their normotensive WKY and Wistar relatives. To test this possibility, SHRs, WKY and Wistar male rats (6-16 weeks old) were killed, perfused and their brains sectioned and immunolabelled for orexin A. Labelled neurons were plotted and counted in the six best labelled hemisections (120 μm apart) of each brain. There were significantly more orexin neurons (+20%) in the medial hypothalamus (medial to fornix) of SHRs compared with WKY and Wistar rats (126 ± 4 versus 106 ± 5 and 104 ± 5 per hemisection, respectively, P hypothalamus did not match the blood pressure phenotypes (69 ± 2 versus 50 ± 3 and 76 ± 4, respectively). The results support the idea that orexin signalling is upregulated

  9. Antihypertensive properties of Allium sativum (garlic) on normotensive and two kidney one clip hypertensive rats.

    Science.gov (United States)

    Nwokocha, C R; Ozolua, R I; Owu, D U; Nwokocha, M I; Ugwu, A C

    2011-12-20

    Allium sativum (garlic) is reported to act as an antihypertensive amidst an inconsistency of evidence. In this study, we investigated the cardiovascular effects of aqueous garlic extracts (AGE) on normotensive and hypertensive rats using the two-kidney one-clip (2K1C) model. Mean arterial blood pressure (MAP) and heart rate (HR) were measured in normotensive and 2K1C rat models anesthetized with thiopentone sodium (50 mg/kg body weight i.p.) through the left common carotid artery connected to a recording apparatus. The jugular vein was cannulated for administration of drugs. Intravenous injection of AGE (5-20 mg/kg) caused a significant (p<0.05) decrease in both MAP and HR in a dose-dependent manner in both the normotensive and 2K1C models, with more effects on normotensive than 2K1C rat model. The dose of 20mg/kg of AGE significantly (p<0.05) reduced systolic (16.7 ± 2.0%), diastolic (26.7 ± 5.2%), MAP (23.1 ± 3.6%) and HR (38.4 ± 4.3%) in normotensive rats. In 2K1C group, it significantly reduced systolic (22.2 ± 2.1 %), diastolic (30.6 ± 3.2%), MAP (28.2 ± 3.1%) and HR (45.2 ± 3.5%) from basal levels. Pulse pressure was significantly elevated (33.3 ±5.1%) in the 2K1C group. Pretreatment of the animals with muscarinic receptor antagonist, atropine (2 mg/kg, i.v.), did not affect the hypotensive and the negative chronotropic activities of the extract. AGE caused a decrease in blood pressure and bradycardia by direct mechanism not involving the cholinergic pathway in both normotensive and 2K1C rats, suggesting a likely involvement of peripheral mechanism for hypotension.

  10. Morphine Analgesia Modification in Normotensive and Hypertensive Female Rats after Repeated Fluoxetine Administration.

    Science.gov (United States)

    Kosiorek-Witek, Anna; Makulska-Nowak, Helena Elżbieta

    2016-01-01

    The purpose of this investigation was to determine through the use of fluoxetine the effect of administering a serotonin reuptake inhibitor over several days on the antinociceptive action of μ-morphine type opioid receptor agonist. Investigations were performed on rats of both sexes, both the WKY normotensive strains as well as on the SHR genetically conditioned hypertensive strains. Results showed that the efficacy of morphine analgesia is higher in the SHR strain compared to normotensive rats (WKY). Surprisingly, repeated administration of fluoxetine reduced morphine analgesia, with the weakening of opioid antinociceptive action comparable to the duration of serotonin reuptake inhibitor administration. It was also concluded that the antinociceptive action of morphine in female rats and the alteration of its efficacy as a result of fluoxetine premedication for several days depend on oestrus cycle phase. The highest sensitivity of female rats to morphine was reported in the dioestrus and oestrus phases; much lower values were reported for the metoestrus phase.

  11. Index of consciousness and bispectral index values are interchangeable during normotension and hypotension but not during non pulsatile flow state during cardiac surgical procedures: a prospective study.

    Science.gov (United States)

    Chakravarthy, Murali; Holla, Srinivasa; Jawali, Vivek

    2010-04-01

    Awareness under anesthesia is an avoidable complication during general anesthesia. Anesthetic depth monitors assist anesthesiologists in providing appropriate levels of anesthesia. Index of consciousness monitoring is a recently introduced monitor in the array of anesthesia depth monitors. The objective of this study was to assess the interchangeability of bispectral index, which is already in clinical use and the recently introduced index of consciousness techniques. The other objective was to assess this interchangeability during normotension, hypotension and during pulseless state in patients undergoing coronary artery bypass graft surgery. This study is a prospective observational study, conducted in a tertiary referral hospital. Fifteen cardiac surgical patients undergoing off pump and conventional coronary artery bypass under cardiopulmonary bypass participated in the study. Bispectral index and index of consciousness monitoring were carried out simultaneously during various stages of consciousness, and assessed for interchangeability. Bland Altman plotting and 'mountain plot' were used to assess the interchangeability. Eleven in the cohort underwent off pump and the rest (n = 4) conventional coronary artery bypass surgery under cardiopulmonary bypass. A set of 887 data were obtained during the study period. The data were classified as those obtained during normotension, hypotension and pulseless state during cardiopulmonary bypass. 732 sets of data were obtained during normotension, 84 during hypotension and 71 during cardiopulmonary bypass. Overall interchangeability was good, suggested by low bias (0.96), high precision (0.54), r value of 0.7 and P value of consciousness values may be interchangeable. The interchangeability is better appreciated during normotension and hypotension but not during non pulsatile state of cardiopulmonary bypass.

  12. Normotension in Lewis and Dahl salt-resistant rats is governed by different genes.

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    Crespo, Kimberley; Chauvet, Cristina; Blain, Marilyne; Ménard, Annie; Roy, Julie; Deng, Alan Y

    2011-03-01

    Inbred rodent models simulating essential hypertension and normotension are useful tools in discovering genes controlling blood pressure (BP) homeostasis. An analysis of a F2 population made from crosses of hypertensive Dahl salt-sensitive (DSS) and normotensive Lewis rats did not detect a BP quantitative trait locus (QTL) on chromosome 7 (Chr 7). However, false negativity could not be excluded. If a BP QTL could be proven to exist, what gene(s) may be responsible for this QTL. We first constructed reciprocal congenic strains for a Chr 7 segment and determined functional domains of prominent candidate genes. A congenic strain made in the DSS rat background exhibited a BP effect, indicating that a BP QTL, C7QTL, inhabits Chr 7. Contrarily, a congenic strain constructed in the Lewis rat background did not change BP, demonstrating a dependence of C7QTL on the DSS rats environment. Among the candidate genes, tachykinin 2 (Tac2), neurexophilin 4 (Nxph4) and retinol dehydrogenase 2 (Rdh2) bear nonsynonymous changes comparing DSS and Lewis rats, but are the same comparing DSS and Dahl salt-resistant (DSR) rats. In contrast, the Lewis alleles of 11-beta-hydroxylase (Cyp11b1), aldosterone synthase (Cyp11b2) and Cytochrome P-450 11B3 (Cyp11b3) are identical to those of DSS rats, but different from those of DSR rats. Thus, the failure to detect a linkage between a Chr 7 segment and BP in F2(DSS × Lewis) can be attributed to false negativity. Tac2, Nxph4 and Rdh2 are priority candidate genes for C7QTL. Lewis and DSR rats are both normotensive, but their underlying genetic determinants are different.

  13. Normotensive sodium loading in conscious dogs: Regulation of renin secretion during beta receptor blockade

    DEFF Research Database (Denmark)

    Bie, Peter; Mølstrøm, Simon; Wamberg, Søren

    2009-01-01

    irrespective of diet. In conclusion, PRC depended on dietary sodium and beta1-adrenergic control as expected; however, the acute sodium-driven decrease in PRC at constant MAP and GFR was unaffected by beta1-receptor blockade demonstrating that renin may be regulated without changes in MAP, GFR, or beta1......Renin secretion is regulated in part by renal nerves operating through beta1-receptors of the renal juxtaglomerular cells. Slow sodium loading may decrease plasma renin (PRC) and cause natriuresis at constant mean arterial blood pressure (MAP) and glomerular filtration rate (GFR). We hypothesized...... that in this setting, renin secretion and renin-dependent sodium excretion are controlled by via the renal nerves and therefore eliminated or reduced by blocking the action of norepinephrine on the juxtaglomerular cells with the beta1-receptor antagonist metoprolol. This was tested in conscious dogs by infusion of Na...

  14. Protective Role of Selective Nitric Oxide Synthase Inhibitor for Treatment of Decompensated Hemorrhagic Shock in Normotensive and Hypertensive Rats

    OpenAIRE

    Majid Khazaei; Babak Barmaki; Ali Nasimi

    2012-01-01

    Introduction: Different vasoactive factors can modulate cardiovascular adaptation to hemorrhagic shock including Nitric Oxide (NO). In this study we investigated the effect of the NO synthase inhibitor for treatment of decompensated hemorrhagic shock in normotensive and hypertensive rats. Methods: Twenty-four male Wistar rats were divided into two groups: The normotensive and hypertensive groups. Hypertension was induced by the DOCA-Salt method for eight weeks. Then, the animals were give...

  15. Postprandial hemodynamics in the conscious rat

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    Anzueto Hernandez, L.; Kvietys, P.R.; Granger, D.N.

    1986-07-01

    The postprandial intestinal hyperemia was studied in conscious and anesthetized rats using the radioactive microsphere technique. Carbohydrate, protein, lipid, and mixed meals, and the vehicle (Tyrode's solution), were placed in the stomach via a gastrostomy tube. In conscious rats, blood flow increased by 40-80% in the duodenum and jejunum 1 h after either a carbohydrate, lipid, protein, or mixed meal. Tyrode's solution produced a comparable hyperemia. Blood flow in the distal bowel segments (ileum, cecum, and colon) was significantly increased only by Tyrode's solution and the carbohydrate meal. The proximal intestinal hyperemia produced by the mixed meal in conscious animals was significantly attenuated by vagotomy yet unaltered by atropine pretreatment. In contrast to the results obtained from conscious rats, the mixed meal did not significantly alter intestinal blood flow in anesthetized animals. The results of this study indicate that the postprandial intestinal hyperemia is much greater in conscious than anesthetized animals. This difference may result from the higher resting blood flows in the latter group. The hyperemic response in conscious animals may be mediated by the vagus nerve.

  16. The action of diazoxide analogs on aortic reactivity in normotensive and spontaneously hypertensive rats.

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    Chona, S; Triggle, D J

    1977-04-01

    Diazoxide and four related 1,2,4-benzothiadiazines reduced the maximum responses to noradrenaline (NA) and KCl in aortic rings from normotensive and spontaneously hypertensive rats (SHR). These agents were more active against NA than against KCl responses, and more effective against either NA or KCl responses in aortae from hypertensive animals. Further studies with V (3-cyclopentenyl-6,7-dichloro-1,2,4-benzothiadiazine-1,1-dioxide), the most active member of the series, showed it to be significantly more effective against NA responses; when calcium was added to calcium-free solutions containing eith NA or KCl, V was more effective in inhibiting either response in SHR aortae and was about 100 times more effective in inhibiting the calcium-NA responses. These data are consistent with previous findings that vascular smooth muscle from normotensive and SHR differs in sensitivity to diazoxide. However, the site(s) at which this difference is exhibited remains to be elucidated.

  17. The mediation of the central histaminergic system in the pressor effect of intracerebroventricularly injected melittin, a phospholipase A2 activator, in normotensive rats.

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    Altinbas, Burcin; Topuz, Bora B; Yilmaz, Mustafa S; Aydin, Cenk; Savci, Vahide; Jochem, Jerzy; Aydin, Sami; Yalcin, Murat

    2012-01-01

    Melittin is a polypeptide component of bee venom that leads to an increase in arachidonic acid release and subsequently in prostaglandin synthesis by activating phospholipase A(2). Recently we demonstrated that centrally or peripherally administrated melittin caused pressor effect and central thromboxane A(2) (TXA(2)) and cholinergic system mediated these effects of melittin. Also centrally injected histamine leads to pressor and bradycardic response by activating central histamine receptors in normotensive rats and central cholinergic system involved the effects of histamine. The present study demonstrates an involvement of the central histaminergic system in melittin-induced cardiovascular effect in normotensive rats. Experiments were carried out in male Sprague Dawley rats. Intracerebroventricularly (i.c.v.) injected melittin (0.5, 1 and 2 nmol) caused dose- and time-dependent increases in mean arterial pressure (MAP) and decrease in heart rate (HR) as we reported previously. Moreover, H(2) receptor antagonist ranitidine (50 nmol; i.c.v.) almost completely and H(3)/H(4) receptor antagonist thioperamide (50 nmol; i.c.v.) partly blocked melittin-evoked cardiovascular effects, whereas H(1) receptor blocker chlorpheniramine (50 nmol; i.c.v.) had no effect. Also centrally injected melittin was accompanied by 28% increase in extracellular histamine concentration in the posterior hypothalamus, as shown in microdialysis studies. In conclusion, results show that centrally administered melittin causes pressor and bradycardic response in conscious rats. Moreover, according to our findings, there is an involvement of the central histaminergic system in melittin-induced cardiovascular effects.

  18. Hemodynamic responses and serum nitrite concentration during uncontrolled hemorrhagic shock in normotensive and hypertensive rats.

    Science.gov (United States)

    Khazaei, Majid; Barmaki, Babak; Nasimi, Ali

    2012-09-01

    We evaluated the effect of hypertension on hemodynamic responses and serum nitrite concentrations in normotensive (NT) and deoxycorticosteron acetate (DOCA)-Salt hypertensive (HT) rats. Uncontrolled hemorrhagic shock was induced in NT and HT rats (n=7 each) by preliminary bleed of 25 ml/kg followed by a 75% tail amputation. The mean arterial pressure (MAP), heart rate and serum nitrite were measured pre-hemorrhage and during hemorrhage. Changes in time-averaged MAP after hemorrhage were significantly greater in HT group than NT. After resuscitation, the HT rats failed to restore MAP to baseline level. Serum nitrite level in both groups was significantly increased during shock period. Survival rate of HT animals was lower than NT group, although it was not statistically significant. Marked reduction of MAP and less improvement after resuscitation suggested the less adaptation of cardiovascular system in HT animals which may interfere with management of these subjects during uncontrolled hemorrhagic shock.

  19. Beta-adrenoceptors in kidney tubules of spontaneously hypertensive and normotensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Struyker-Boudier, H.A.J.; Vervoort-Peters, L.H.T.M.; Rousch, M.J.M.; Smits, J.F.M.; Thijssen, H.H.W.

    1986-01-13

    Beta-adrenoceptor binding characteristics were determined in different fractions of rat kidney tubules using a (/sup 125/Iodo)-(-)-cyanopindolol (ICYP) binding assay. The highest amount of binding sites was found in a fraction containing predominantly distal tubular fragments. In a separate series of experiments the ICYP binding characteristics were compared in whole tubular fractions from spontaneously hypertensive (SHR) and normotensive Wistar Kyoto rats (WKY) of different ages. The maximum number of binding sites was significantly higher both in young (3 weeks) and adult (14 weeks) SHR when compared to age-matched WKY. These studies showed the presence of beta-adrenoceptor binding sites in rat kidney tubules and support the potential importance of tubular beta-adrenoceptors in the development of spontaneous hypertension and in the mechanism of antihypertensive action of beta-blockers. 35 references, 1 figure, 3 tables.

  20. Nonlinear system analysis of renal autoregulation in normotensive and hypertensive rats

    DEFF Research Database (Denmark)

    Chon, K H; Chen, Y M; Holstein-Rathlou, N H;

    1998-01-01

    We compared the dynamic characteristics in renal autoregulation of blood flow of normotensive Sprague-Dawley rats (SDR) and spontaneously hypertensive rats (SHR), using both linear and nonlinear systems analysis. Linear analysis yielded only limited information about the differences in dynamics...... of nonlinear interactions between the oscillatory components of the myogenic mechanism and tubuloglomerular feedback (TGF) at the level of whole kidney blood flow in SDR. An interaction between these two mechanisms had previously been revealed for SDR only at the single nephron level. However, nonlinear......, NMSE are significantly higher in SHR than SDR, suggesting a more complex nonlinear system in SHR. The contribution of the third-order kernel in describing the dynamics of renal autoregulation in arterial blood pressure and blood flow was found to be important. Moreover, we have identified the presence...

  1. Structural properties of lipid reconstructs and lipid composition of normotensive and hypertensive rat vascular smooth muscle cell membranes

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    T.R. Oliveira

    2009-09-01

    Full Text Available Multiple cell membrane alterations have been reported to be the cause of various forms of hypertension. The present study focuses on the lipid portion of the membranes, characterizing the microviscosity of membranes reconstituted with lipids extracted from the aorta and mesenteric arteries of spontaneously hypertensive (SHR and normotensive control rat strains (WKY and NWR. Membrane-incorporated phospholipid spin labels were used to monitor the bilayer structure at different depths. The packing of lipids extracted from both aorta and mesenteric arteries of normotensive and hypertensive rats was similar. Lipid extract analysis showed similar phospholipid composition for all membranes. However, cholesterol content was lower in SHR arteries than in normotensive animal arteries. These findings contrast with the fact that the SHR aorta is hyporeactive while the SHR mesenteric artery is hyperreactive to vasopressor agents when compared to the vessels of normotensive animal strains. Hence, factors other than microviscosity of bulk lipids contribute to the vascular smooth muscle reactivity and hypertension of SHR. The excess cholesterol in the arteries of normotensive animal strains apparently is not dissolved in bulk lipids and is not directly related to vascular reactivity since it is present in both the aorta and mesenteric arteries. The lower cholesterol concentrations in SHR arteries may in fact result from metabolic differences due to the hypertensive state or to genes that co-segregate with those that determine hypertension during the process of strain selection.

  2. Sodium Bicarbonate Treatment during Transient or Sustained Lactic Acidemia in Normoxic and Normotensive Rats

    Science.gov (United States)

    Valenza, Franco; Pizzocri, Marta; Salice, Valentina; Chevallard, Giorgio; Fossali, Tommaso; Coppola, Silvia; Froio, Sara; Polli, Federico; Gatti, Stefano; Fortunato, Francesco; Comi, Giacomo P.; Gattinoni, Luciano

    2012-01-01

    Introduction Lactic acidosis is a frequent cause of poor outcome in the intensive care settings. We set up an experimental model of lactic acid infusion in normoxic and normotensive rats to investigate the systemic effects of lactic acidemia per se without the confounding factor of an underlying organic cause of acidosis. Methodology Sprague Dawley rats underwent a primed endovenous infusion of L(+) lactic acid during general anesthesia. Normoxic and normotensive animals were then randomized to the following study groups (n = 8 per group): S) sustained infusion of lactic acid, S+B) sustained infusion+sodium bicarbonate, T) transient infusion, T+B transient infusion+sodium bicarbonate. Hemodynamic, respiratory and acid-base parameters were measured over time. Lactate pharmacokinetics and muscle phosphofructokinase enzyme's activity were also measured. Principal Findings Following lactic acid infusion blood lactate rose (P<0.05), pH (P<0.05) and strong ion difference (P<0.05) drop. Some rats developed hemodynamic instability during the primed infusion of lactic acid. In the normoxic and normotensive animals bicarbonate treatment normalized pH during sustained infusion of lactic acid (from 7.22±0.02 to 7.36±0.04, P<0.05) while overshoot to alkalemic values when the infusion was transient (from 7.24±0.01 to 7.53±0.03, P<0.05). When acid load was interrupted bicarbonate infusion affected lactate wash-out kinetics (P<0.05) so that blood lactate was higher (2.9±1 mmol/l vs. 1.0±0.2, P<0.05, group T vs. T+B respectively). The activity of phosphofructokinase enzyme was correlated with blood pH (R2 = 0.475, P<0.05). Conclusions pH decreased with acid infusion and rose with bicarbonate administration but the effects of bicarbonate infusion on pH differed under a persistent or transient acid load. Alkalization affected the rate of lactate disposal during the transient acid load. PMID:23029373

  3. Moderate exercise training promotes adaptations in coronary blood flow and adenosine production in normotensive rats

    Directory of Open Access Journals (Sweden)

    Fernanda R. Roque

    2011-01-01

    Full Text Available OBJECTIVES: Aerobic exercise training prevents cardiovascular risks. Regular exercise promotes functional and structural adaptations that are associated with several cardiovascular benefits. The aim of this study is to investigate the effects of swimming training on coronary blood flow, adenosine production and cardiac capillaries in normotensive rats. METHODS: Wistar rats were randomly divided into two groups: control (C and trained (T. An exercise protocol was performed for 10 weeks and 60 min/day with a tail overload of 5% bodyweight. Coronary blood flow was quantified with a color microsphere technique, and cardiac capillaries were quantified using light microscopy. Adenine nucleotide hydrolysis was evaluated by enzymatic activity, and protein expression was evaluated by western blot. The results are presented as the means ± SEMs (p<0.05. RESULTS: Exercise training increased the coronary blood flow and the myocardial capillary-to-fiber ratio. Moreover, the circulating and cardiac extracellular adenine nucleotide hydrolysis was higher in the trained rats than in the sedentary rats due to the increased activity and protein expression of enzymes, such as E-NTPDase and 59- nucleotidase. CONCLUSIONS: Swimming training increases coronary blood flow, number of cardiac capillaries, and adenine nucleotide hydrolysis. Increased adenosine production may be an important contributor to the enhanced coronary blood flow and angiogenesis that were observed in the exercise-trained rats; collectively, these results suggest improved myocardial perfusion.

  4. β-Adrenoceptor blocking properties of dl-nebivolol and its enantiomers in the pithed normotensive rat

    NARCIS (Netherlands)

    Schneider, J.; Fruh, C.; Wilffert, B.; Peters, Thies

    1991-01-01

    In the pithed normotensive rat, the effects of dl-nebivolol and its enantiomers on the (-)-adrenaline (epinephrine)- and electrical stimulation-induced increases in heart rate (HR) and diastolic blood pressure (DBP) were investigated. dl-Nebivolol dose-dependently (10-7to 10-5mol/kg intravenously) a

  5. Blood Pressure Lowering Effect of Adenanthera pavonina Seed Extract on Normotensive Rats

    Directory of Open Access Journals (Sweden)

    Janet M. Makinde

    2009-03-01

    Full Text Available The effect of Adenanthera pavonina (AP seed extract on the blood pressure of normotensive rats wasevaluated. Twelve adult male Wistar rats divided into 3 groups of 4 animals each were used and were treatedorally with normal saline (control group, propanolol (positive control, and was given at 1mg/kg and 200mg/kgof AP seed extract over a 4- week period. Condon manometer was used to measure the mean arterial bloodpressure. The mean arterial blood pressure of the normal saline treated animal was 60mmHg, those of propanololtreated animals was 23mmHg while the 200mg/kg extract treated group was 30mmHg. Phytochemical screeningshowed that the extract contained cardiac glycosides, tannins, saponins, alkaloids and flavonoids. Cyanogeneticglycosides and anthraquinones were absent. The sodium level for the 200mg/kg group was significantly lowerthan that of control group. The total bilirubin, total protein and the globulin fraction were significantly higher inthe extract treated groups compared to the control group. Histopathological examination showed that the extractdid not cause any significant lesion changes in the liver, kidney and even the testes. The study showed thatAdenanthera pavonina seed extract have the potential to cause a blood pressure lowering effect. The serumbiochemistry changes may suggest that the extract has a tonic effect on the kidneys and the liver and theseorgans play central role in drug metabolism. Absence of significant lesion in the kidney, liver and testes mayindicate that the plant is safe for medicinal use.

  6. Protective role of selective nitric oxide synthase inhibitor for treatment of decompensated hemorrhagic shock in normotensive and hypertensive rats.

    Science.gov (United States)

    Khazaei, Majid; Barmaki, Babak; Nasimi, Ali

    2012-01-01

    Different vasoactive factors can modulate cardiovascular adaptation to hemorrhagic shock including Nitric Oxide (NO). In this study we investigated the effect of the NO synthase inhibitor for treatment of decompensated hemorrhagic shock in normotensive and hypertensive rats. Twenty-four male Wistar rats were divided into two groups: The normotensive and hypertensive groups. Hypertension was induced by the DOCA-Salt method for eight weeks. Then, the animals were given hemorrhagic shock by continuously withdrawing blood until the mean arterial pressure (MAP) reached to 40 mmHg. The animals were maintained in the shock state for 120 minutes. Subsequently, they were randomly assigned to L-NAME-treated and non-treated groups and monitored for 60 minutes. The survival time was recorded. Blood samples were taken before and after the shock and 60 minutes after L-NAME administration. Infusion of L-NAME caused a significant increase in MAP in normotensive animals, however, slightly increased MAP in hypertensive animals. The heart rate did not significantly alter. Hemorrhage caused a marked increase in serum nitrite levels in both groups (P<0.05). L-NAME treatment significantly reduced the serum nitrite concentration in the normotensive group (P<0.05), without any change in the hypertensive group. All animals who received L-NAME treatment survived at the end of experiment. Fifty percent of the hypertensive animals died four hours after the experiment. The 72-hour survival rate was similar in the L-NAME treated groups. L-NAME infusion during decompensated hemorrhagic shock plays a protective role in the improvement of hemodynamic responses and short-term survival rate in normotensive animals.

  7. Both sustained orthostasis and inverse-orthostasis may elicit hypertension in conscious rat

    Science.gov (United States)

    Raffai, Gábor; Dézsi, László; Mészáros, Márta; Kollai, Márk; Monos, Emil

    2007-02-01

    The organism is exposed to diverse orthostatic stimuli, which can induce several acute and chronic adaptive responses. In this study, we investigated hemodynamic responses elicited by short-term and intermediate-term various orthostatic stimuli, using normotensive and hypertensive rat models. Arterial blood pressure and heart rate were measured by telemetry. Hypertension was induced by NO-synthase blockade. Effect of orthostatic and inverse-orthostatic body positions were examined in 45∘ head-up (HUT) or head-down tilt (HDT), either for 5 min duration repeated 3 times each with a 5-min pause " R", or as sustained tilting for 120 min " S". Data are given as mean±SEM. In normotensives, horizontal control blood pressure was R115.4±1.4/S113.7±1.6mmHg and heart rate was R386.4±7.0/S377.9±8.8BPM. HUT changed blood pressure by Rblood pressure increase by R6.2(phypertension, horizontal control hemodynamic parameters were R138.4±2.6/S140.3±2.7mmHg and R342.1±12.0/S346.0±8.3BPM, respectively. HUT and HDT changed blood pressure further by Rhypertensive conscious rats restricted from longitudinal locomotion respond to sustained orthostasis or inverse-orthostasis related gravitational stimuli with moderate or augmented hypertension, respectively.

  8. The NO stimulator, Catestatin, improves the Frank-Starling response in normotensive and hypertensive rat hearts.

    Science.gov (United States)

    Angelone, T; Quintieri, A M; Pasqua, T; Filice, E; Cantafio, P; Scavello, F; Rocca, C; Mahata, S K; Gattuso, A; Cerra, M C

    2015-08-01

    The myocardial response to mechanical stretch (Frank-Starling law) is an important physiological cardiac determinant. Modulated by many endogenous substances, it is impaired in the presence of cardiovascular pathologies and during senescence. Catestatin (CST:hCgA352-372), a 21-amino-acid derivate of Chromogranin A (CgA), displays hypotensive/vasodilatory properties and counteracts excessive systemic and/or intra-cardiac excitatory stimuli (e.g., catecholamines and endothelin-1). CST, produced also by the myocardium, affects the heart by modulating inotropy, lusitropy and the coronary tone through a Nitric Oxide (NO)-dependent mechanism. This study evaluated the putative influence elicited by CST on the Frank-Starling response of normotensive Wistar-Kyoto (WKY) and hypertensive (SHR) hearts by using isolated and Langendorff perfused cardiac preparations. Functional changes were evaluated on aged (18-month-old) WKY rats and SHR which mimic human chronic heart failure (HF). Comparison to WKY rats, SHR showed a reduced Frank-Starling response. In both rat strains, CST administration improved myocardial mechanical response to increased end-diastolic pressures. This effect was mediated by EE/IP3K/NOS/NO/cGMP/PKG, as revealed by specific inhibitors. CST-dependent positive Frank-Starling response is paralleled by an increment in protein S-Nitrosylation. Our data suggested CST as a NO-dependent physiological modulator of the stretch-induced intrinsic regulation of the heart. This may be of particular importance in the aged hypertrophic heart, whose function is impaired because of a reduced systolic performance accompanied by delayed relaxation and increased diastolic stiffness.

  9. Effects of nimodipine on learning in normotensive and spontaneously hypertensive rats.

    Science.gov (United States)

    Meneses, A; Terrón, J A; Ibarra, M; Hong, E

    1997-04-01

    It is well known that the calcium channel blocker, nimodipine, has beneficial effects on learning in either aged or hypertensive animals and humans. However, no attempts have been made to investigate if nimodipine can reverse the synergistic deleterious effects of aging and hypertension in the same subject. Therefore, this study investigated the effects of stable infusions of nimodipine in the autoshaping learning task using middle-aged normotensive (WKY) and hypertensive (SHR) rats. WKY and SHR of 12 months of age were implanted with osmotic minipumps releasing either vehicle or nimodipine (0.4 mg/kg/day). After 3 weeks of treatment, the animals received autoshaping training sessions during 4 consecutive days. The WKY animals treated with nimodipine exhibited the highest levels of learning during the last session, the rank order being WKY-nimodipine > SHR-nimodipine > WKY-vehicle > SHR-vehicle. These results confirm that nimodipine can reverse the impairing effects of either aging or hypertension on learning; the presence of both conditions, however, might produce more severe dysfunctional changes that cannot be totally reversed by nimodipine.

  10. Functional alterations of mesenteric small resistance arteries in Milan hypertensive and normotensive rats.

    Science.gov (United States)

    Rizzoni, Damiano; Castellano, Maurizio; Porteri, Enzo; Giacchè, Mara; Ferrari, Patrizia; Cusi, Daniele; De Ciuceis, Carolina; Boari, Gianluca E M; Rosei, Enrico Agabiti

    2009-07-01

    The Milan hypertensive rat strain (MHS) is a genetic strain in which cardiovascular phenotypes seem to be dependent, at least in part, on adducin gene polymorphisms. The aim of our study was to evaluate the structure, contractile responses and endothelium-dependent vasodilation in mesenteric small resistance arteries in 12-week-old MHS, (n=7), age-matched Milan normotensive rats (MNS, n=7) and congenic strains in which the DNA segments carrying the alpha-adducin locus from the MHS have been introgressed into the MNS (MNA, n=7). Systolic blood pressure (tail cuff) and left ventricular weight to body weight were measured. Mesenteric small arteries were dissected and mounted on a micromyograph; the media:lumen ratio was then calculated. Concentration-response curves to acetylcholine and to norepinephrine (NE) were created. Systolic blood pressure was significantly increased in the MHS and MNA strains compared with the MNS. No significant difference in mesenteric small resistance artery structure was observed among the groups; however, a slightly more elevated media:lumen ratio was observed in MNA compared with the MNS. In contrast, left ventricular weight to body weight was significantly increased and ACH-induced dilatation was significantly impaired in the MHS and in MNA compared with MNS. The concentration-response curve to NE in the MHS showed significantly reduced sensitivity to NE; however, maximum contraction was increased in the MHS vs. the other groups. The MHS presents cardiac (but not vascular) remodeling, endothelial dysfunction and a peculiar contractile response to NE, compared with the other groups. The systolic blood pressure increase and trend to vascular remodeling in MNA support the pathogenic role of alpha-adducin.

  11. Effects of high dose olive leaf extract on haemodynamic and oxidative stress parameters in normotensive and spontaneously hypertensive rats

    Directory of Open Access Journals (Sweden)

    Dekanski Dragana

    2014-01-01

    Full Text Available Antihypertensive activity of natural antioxidant, olive leaf extract (OLE is known, but its influence on cardiovascular system when administered in a high dose has not been investigated yet. Our aim was to determine the acute effects of excessive intake of standardized OLE on blood pressure, heart rate and oxidative status in both spontaneously hypertensive rats and normotensive Wistar rats. Systolic arterial pressure and heart rate were measured using a tail-cuff, pneumatic pulse detector, before, 60 and 120 minutes after intragastric OLE administration. Activities of catalase, glutathione peroxidase, superoxide dismutase (SOD and glutathione reductase in erythrocytes, as well as lipid peroxidation in plasma (pTBARS were measured at the same time points, spectrophotometrically. High-dose OLE did not influence blood pressure, heart rate and pTBARS in normotensive rats, while SOD, catalase, and glutathione reductase activities significantly increased. The same dose significantly decreased blood pressure in hypertensive rats, but increased pTBARS and SOD activity. Excessive oral intake of OLE induced moderate hypotensive effects in spontaneously hypertensive rats only, suggesting absence of harmful haemodynamic effects after oral overdose in both rats strain. However, its prooxidative role when given in high dose in hypertensive organism should not be neglected. [Projekat Ministarstva nauke Republike Srbije, br. 175096

  12. POTENT HYPOTENSIVE EFFECTS OF ORPHANIN FQ IN CONSCIOUS STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS

    Institute of Scientific and Technical Information of China (English)

    魏英杰; 黄其擎; 朱燕青; 米立国; 张肇康; 汤健; 丁金凤

    1998-01-01

    Orphanin FQ(OFQ) ov ncciceptin is a novel neuropepride consisting of 17 amino acids. This peptide has a primary structure reminiscent of that of opioid peptide but exhibits an opposite effect to nmke aninaals hyperreaetive. The effect of this new pepfide on cardiovascular function are not completely known. The present study was conducted to investigate the effect of intravenous bolus injection of orphauln FQ on mean arterial blood prestum (MABP) in conscions stroke-prone spontaneously hypertensive rats (SHRap). Adult male SHRap and Wistar normotensive rats (250~300 g body weight, 2. 5~3 months old) were used in this study. The MABP was measured in the conscious state by a rail-cuff method. In SHRap model, intravenous bolus injecticm of orphanin FQ or Tyrl-orphanin FQ (0. 5 mg/kg) induced a prolonged and marked reduction in MABP. The maximum changes in MABP were -30. 2±4. 2mmHg by orphauln FQ and -28. 2±4. 7mmHg by Tyrl-orphanin FQ at 10 rain after administration,and this effect lasted over 30 rain. The Phel→Tyr substitution in orphanin FQ was found to retain almost fully hypotensive activity. Pretreatment of SHRap with naloxone-HCI(60μg/kg), 5 min before the injection of orphauln FQ, did not block the hypotenslve effect M orphanln FQ. Therefore, opiuld receptors could not account for the hypotensive effect oforphanin FQ in SHRap. In Wistar rats, Mtravenous bolus injection of the same dose of orphanin FQ did not cause a change in MABP. These obeervations suggest that orphauln FQ is a novel hypotensive peptide and may have some role in the regulation of blood pressure in SHRap, rather than in normotensive rats. The exact underlying mechanisms are waiting to be clarified.

  13. Differential regulation of atrial contraction by P1 and P2 purinoceptors in normotensive and spontaneously hypertensive rats.

    Science.gov (United States)

    Rodrigues, Juliano Quintella Dantas; da Silva, Edilson Dantas; de Magalhães Galvão, Kleber; Miranda-Ferreira, Regiane; Caricati-Neto, Afonso; Jurkiewicz, Neide Hyppolito; Garcia, Antônio G; Jurkiewicz, Aron

    2014-03-01

    In the normotensive rat atrium, adenosine-5'-triphosphate and uridine-5'-triphosphate exert a biphasic effect consisting of an initial negative inotropic effect (NIE) followed by a subsequent positive inotropic effect (PIE). We comparatively studied these responses in normotensive Wistar rats (NWRs) and spontaneously hypertensive rats (SHRs). Compared with NWRs, the NIE responses in the atria were lower and the PIE responses were higher in SHRs. The P1 purinoceptor antagonist, D 8-cyclopentyl-1,3-dipropylxanthine, partially blocked the NIE responses of both ATP and UTP and mildly enhanced the PIE responses in both NWRs and SHRs. Furthermore, the P2 purinoceptor blockers suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid tetrasodium salt induced a pronounced block of the PIE responses in both atria types. The PIE responses to ATP were inhibited more efficiently by nifedipine. These responses were depressed by ryanodine and, to a lesser extent, carbonyl cyanide 3-chlorophenylhydrazone in SHR atria compared with NWR atria. The higher responses in SHR rats suggest the existence of an augmented endoplasmic reticulum Ca(2+) store and faster mitochondrial Ca(2+) cycling in SHR atria compared with NWR atria. These data support the hypothesis that a dysfunction of purinergic neurotransmission and enhanced sympathetic activity are contributing factors in the pathogenesis of hypertension.

  14. Reflex bradycardia induced by hydralazine in sino-aortic deafferented conscious rats.

    Science.gov (United States)

    Sánchez-Salvatori, M A; Vidrio, H

    2003-02-01

    1. It is generally recognized that the vasodilator hydralazine produces hypotension accompanied by baroreflex-mediated tachycardia. In some experimental conditions, however, the accompanying heart rate change is bradycardia, a paradoxical response which has not been satisfactorily explained. The present study examined the possibility of hydralazine-induced bradycardia being mediated by vagal or sympathetic afferents activated by changes in left ventricular pressure. 2. Systolic blood pressure and heart rate responses to hydralazine were recorded in conscious normotensive intact rats by a tail cuff method and compared with responses in animals subjected to previous sino-aortic deafferentation (SAD) to remove the influence of the arterial baroreflex. Responses were also obtained after blockade of myocardial afferent vagal C-fibres with urethane, of efferent vagal impulses to the heart with methylatropine, of positive inotropic effects of hydralazine with atenolol, and of prostanoid sensitization of myocardial nerve fibres with indomethacin. 3. Hydralazine produced hypotension and tachycardia in intact rats, and hypotension and bradycardia in SAD animals. In intact rats, this pattern was not affected by any of the pretreatments, while in SAD rats, all pretreatments reversed the bradycardia to hydralazine. 4. The present results indicate that suppression of the arterial baroreflex by SAD propitiates the appearance of a bradycardiac response to hydralazine. This reaction probably results from activation of a vagal cardiodepressant reflex originating in the heart, as suggested by its blockade by drugs acting at various sites along the reflex arch.

  15. Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Durand, M.T.; Mota, A.L. [Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Barale, A.R. [Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG (Brazil); Castania, J.A.; Fazan, R. Jr.; Salgado, H.C. [Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-03-16

    The time to reach the maximum response of arterial pressure, heart rate and vascular resistance (hindquarter and mesenteric) was measured in conscious male spontaneously hypertensive (SHR) and normotensive control rats (NCR; Wistar; 18-22 weeks) subjected to electrical stimulation of the aortic depressor nerve (ADN). The parameters of stimulation were 1 mA intensity and 2 ms pulse length applied for 5 s, using frequencies of 10, 30, and 90 Hz. The time to reach the hemodynamic responses at different frequencies of ADN stimulation was similar for SHR (N = 15) and NCR (N = 14); hypotension = NCR (4194 ± 336 to 3695 ± 463 ms) vs SHR (3475 ± 354 to 4494 ± 300 ms); bradycardia = NCR (1618 ± 152 to 1358 ± 185 ms) vs SHR (1911 ± 323 to 1852 ± 431 ms), and the fall in hindquarter vascular resistance = NCR (6054 ± 486 to 6550 ± 847 ms) vs SHR (4849 ± 918 to 4926 ± 646 ms); mesenteric = NCR (5574 ± 790 to 5752 ± 539 ms) vs SHR (5638 ± 648 to 6777 ± 624 ms). In addition, ADN stimulation produced baroreflex responses characterized by a faster cardiac effect followed by a vascular effect, which together contributed to the decrease in arterial pressure. Therefore, the results indicate that there is no alteration in the conduction of the electrical impulse after the site of baroreceptor mechanical transduction in the baroreflex pathway (central and/or efferent) in conscious SHR compared to NCR.

  16. Central cholinergic control of vasopressin release in conscious rats

    Energy Technology Data Exchange (ETDEWEB)

    Iitake, K.; Share, L.; Ouchi, Y.; Crofton, J.T.; Brooks, D.P.

    1986-08-01

    Intracerebroventricular (icv) administration of carbachol into conscious rats evoked a substantial increase in vasopressin secretion and blood pressure in a dose-dependent manner. These effects were blocked by pretreatment with the muscarinic blocker, atropine (10 g icv), but not by the nicotinic blocker, hexamethonium (10 g icv). Hexamethonium did, however, block the increase in blood pressure, the decrease in heart rate, and they very small elevation in the plasma vasopressin concentration induced by nicotine (10 g icv). These results indicate that stimulation of either central nicotinic or muscarinic receptors can affect the cardiovascular system and suggest that the cholinergic stimulation of vasopressin secretion may involve primarily muscarinic receptors in the conscious rat.

  17. Lipopolysaccharide-induced acute renal failure in conscious rats

    DEFF Research Database (Denmark)

    Jonassen, Thomas E N; Graebe, Martin; Promeneur, Dominique

    2002-01-01

    In conscious, chronically instrumented rats we examined 1) renal tubular functional changes involved in lipopolysaccharide (LPS)-induced acute renal failure; 2) the effects of LPS on the expression of selected renal tubular water and sodium transporters; and 3) effects of milrinone, a phosphodies......In conscious, chronically instrumented rats we examined 1) renal tubular functional changes involved in lipopolysaccharide (LPS)-induced acute renal failure; 2) the effects of LPS on the expression of selected renal tubular water and sodium transporters; and 3) effects of milrinone......). LPS-induced fall in GFR and proximal tubular outflow were sustained on day 2. Furthermore, LPS-treated rats showed a marked increase in fractional distal water excretion, despite significantly elevated levels of plasma vasopressin (AVP). Semiquantitative immunoblotting showed that LPS increased......-alpha and lactate, inhibited the LPS-induced tachycardia, and exacerbated the acute LPS-induced fall in GFR. Furthermore, Ro-20-1724-treated rats were unable to maintain MAP. We conclude 1) PDE3 or PDE4 inhibition exacerbates LPS-induced renal failure in conscious rats; and 2) LPS treated rats develop an escape...

  18. Relaxin is a potent renal vasodilator in conscious rats

    OpenAIRE

    Danielson, Lee A.; Sherwood, O. David; Conrad, Kirk P.

    1999-01-01

    The kidneys and other nonreproductive organs vasodilate during early gestation; however, the “pregnancy hormones” responsible for the profound vasodilation of the renal circulation during pregnancy are unknown. We hypothesized that the ovarian hormone relaxin (RLX) contributes. Therefore, we tested whether the administration of RLX elicits renal vasodilation and hyperfiltration in conscious adult, intact female rats. After several days of treatment with either purified porcine RLX or recombin...

  19. Effect of angiotensin Ⅱ type Ⅰ receptor blocker losartan on bone deterioration in orchiectomized male hypertensive and normotensive rats

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya-feng; QIN Ling; Timothy CY Kwok; Benson HY Yeung; LI Guo-dong; LIU Fan

    2013-01-01

    Background Epidemiological study showed that the use of angiotensin-converting enzyme inhibitors was associated with higher bone mineral density (BMD) in older people,especially male subjects,which suggested that angiotensin Ⅱ may have a detrimental effect on bone.Therefore,blocking its effect may have a beneficial effect on bone health.Methods Six-month-old male spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) were used.Animals of each model were randomly assigned to the following four groups:Group 1,SHAM operated+vehicle;Group 2,orchidectomy (ORX)+vehicle; Group 3,ORX+low-dose losartan (10 mg.kg-1·d-1); and Group 4,ORX+high-dose losartan (25 mg.kg-1.d-1).Blood pressure was recorded weekly.SHAM and ORX operations were performed,followed by daily losartan and vehicle treatment from day 4 after operation for 16 weeks.Serum and 24-hour urine samples were collected for measurement of bone turnover markers before euthanasia and then the left femur was collected for measurements of BMD and microarchitecture before mechanical test.Results Urine deoxypyridinoline/urine creatinine (DPD/Cr) ratio was significantly higher in SHR than in WKY.BMD and microarchitecture parameters also showed bone deterioration in SHR.After ORX,serum osteocalcin concentration decreased and urine DPD/Cr ratio increased significantly accompanied by a significant decrease in cortical and trabecular BMD and cortical bone thickness in both WKY and SHR.High-dose losartan significantly increased DPD in urine in both SHR and WKY.Apart from marginal favorable changes in bone architecture in WKY treated with high-dose losartan,losartan did not show significant effect on BMD,bone area,bone microarchitecture,and mechanical properties in both SHR and WKY.Conclusion Angiotensin Ⅱ type Ⅰ receptor blocker losartan was not able to demonstrate significant effect on ORX-induced bone deterioration in both hypertensive and normotensive rats.

  20. 1-Nitro-2-phenylethane, the main constituent of the essential oil of Aniba canelilla, elicits a vago-vagal bradycardiac and depressor reflex in normotensive rats.

    Science.gov (United States)

    de Siqueira, Rodrigo José Bezerra; Macedo, Francisco Igor Bulcão; Interaminense, Leylliane de Fátima Leal; Duarte, Gloria Pinto; Magalhães, Pedro Jorge Caldas; Brito, Teresinha Silva; da Silva, Joyce Kelly Rosário; Maia, José Guilherme Soares; Sousa, Pergentino José da Cunha; Leal-Cardoso, José Henrique; Lahlou, Saad

    2010-07-25

    Previously, it was shown that intravenous (i.v.) treatment with the essential oil of Aniba canelilla (EOAC) elicited a hypotensive response that is due to active vascular relaxation rather than to the withdrawal of sympathetic tone. The present study investigated mechanisms underlying the cardiovascular responses to 1-nitro-2-phenylethane, the main constituent of the EOAC. In pentobarbital-anesthetized normotensive rats, 1-nitro-2-phenylethane (1-10mg/kg, i.v.) elicited dose-dependent hypotensive and bradycardiac effects which were characterized in two periods (phases 1 and 2). The first rapid component (phase 1) evoked by 1-nitro-2-phenylethane (10mg/kg) was fully abolished by bilateral vagotomy, perineural treatment of both cervical vagus nerves with capsaicin (250 microg/ml) and was absent after left ventricle injection. However, pretreatment with capsazepine (1mg/kg, i.v.) or ondansetron (30 microg/kg, i.v.) did not alter phase 1 of the cardiovascular responses to 1-nitro-2-phenylethane (10mg/kg, i.v.). In conscious rats, 1-nitro-2-phenylethane (1-10mg/kg, i.v.) evoked rapid hypotensive and bradycardiac (phase 1) effects that were fully abolished by methylatropine (1mg/kg, i.v.). It is concluded that 1-nitro-2-phenylethane induces a vago-vagal bradycardiac and depressor reflex (phase 1) that apparently results from the stimulation of vagal pulmonary rather than cardiac C-fiber afferents. The transduction mechanism of the 1-nitro-2-phenylethane excitation of C-fiber endings is not fully understood and does not appear to involve activation of either Vanilloid TPRV(1) or 5-HT(3) receptors. The phase 2 hypotensive response to 1-nitro-2-phenylethane seems to result, at least in part, from a direct vasodilatory effect since 1-nitro-2-phenylethane (1-300 microg/ml) induced a concentration-dependent reduction of phenylephrine-induced contraction in rat endothelium-containing aorta preparations.

  1. Consciousness

    National Research Council Canada - National Science Library

    Zeman, A

    2001-01-01

    Consciousness is topical, for reasons including its renewed respectability among psychologists, rapid progress in the neuroscience of perception, memory and action, advances in artificial intelligence...

  2. Fullerenols and glucosamine fullerenes reduce infarct volume and cerebral inflammation after ischemic stroke in normotensive and hypertensive rats.

    Science.gov (United States)

    Fluri, Felix; Grünstein, Dan; Cam, Ertugrul; Ungethuem, Udo; Hatz, Florian; Schäfer, Juliane; Samnick, Samuel; Israel, Ina; Kleinschnitz, Christoph; Orts-Gil, Guillermo; Moch, Holger; Zeis, Thomas; Schaeren-Wiemers, Nicole; Seeberger, Peter

    2015-03-01

    Cerebral inflammation plays a crucial role in the pathophysiology of ischemic stroke and is involved in all stages of the ischemic cascade. Fullerene derivatives, such as fullerenol (OH-F) are radical scavengers acting as neuroprotective agents while glucosamine (GlcN) attenuates cerebral inflammation after stroke. We created novel glucosamine-fullerene conjugates (GlcN-F) to combine their protective effects and compared them to OH-F regarding stroke-induced cerebral inflammation and cellular damage. Fullerene derivatives or vehicle was administered intravenously in normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) immediately after transient middle cerebral artery occlusion (tMCAO). Infarct size was determined at day 5 and neurological outcome at days 1 and 5 after tMCAO. CD68- and NeuN-staining were performed to determine immunoreactivity and neuronal survival respectively. Cytokine and toll like receptor 4 (TLR-4) expression was assessed using quantitative real-time PCR. Magnetic resonance imaging revealed a significant reduction of infarct volume in both, WKY and SHR that were treated with fullerene derivatives. Treated rats showed an amelioration of neurological symptoms as both OH-F and GlcN-F prevented neuronal loss in the perilesional area. Cerebral immunoreactivity was reduced in treated WKY and SHR. Expression of IL-1β and TLR-4 was attenuated in OH-F-treated WKY rats. In conclusion, OH-F and GlcN-F lead to a reduction of cellular damage and inflammation after stroke, rendering these compounds attractive therapeutics for stroke.

  3. Magnetic Resonance Imaging Quantification of Regional Cerebral Blood Flow and Cerebrovascular Reactivity to Carbon Dioxide in Normotensive and Hypertensive Rats

    Science.gov (United States)

    Leoni, Renata F.; Paiva, Fernando F.; Henning, Erica C.; Nascimento, George C.; Tannús, Alberto; de Araujo, Draulio B.; Silva, Afonso C.

    2011-01-01

    Hypertension afflicts 25% of the general population and over 50% of the elderly. In the present work, arterial spin labeling MRI was used to non-invasively quantify regional cerebral blood flow (CBF), cerebrovascular resistance and CO2 reactivity in spontaneously hypertensive rats (SHR) and in normotensive Wistar Kyoto rats (WKY), at two different ages (3 months and 10 months) and under the effects of two anesthetics, α-chloralose and 2% isoflurane (1.5 MAC). Repeated CBF measurements were highly consistent, differing by less than 10% and 18% within and across animals, respectively. Under α-chloralose, whole brain CBF at normocapnia did not differ between groups (young WKY: 61±3ml/100g/min; adult WKY: 62±4ml/100g/min; young SHR: 70±9ml/100g/min; adult SHR: 69±8ml/100g/min), indicating normal cerebral autoregulation in SHR. At hypercapnia, CBF values increased significantly, and a linear relationship between CBF and PaCO2 levels was observed. In contrast, 2% isoflurane impaired cerebral autoregulation. Whole brain CBF in SHR was significantly higher than in WKY rats at normocapnia (young SHR: 139±25ml/100g/min; adult SHR: 104±23ml/100g/min; young WKY: 55±9ml/100g/min; adult WKY: 71±19ml/100g/min). CBF values increased significantly with increasing CO2; however, there was a clear saturation of CBF at PaCO2 levels greater than 70 mmHg in both young and adult rats, regardless of absolute CBF values, suggesting that isoflurane interferes with the vasodilatory mechanisms of CO2. This behavior was observed for both cortical and subcortical structures. Under either anesthetic, CO2 reactivity values in adult SHR were decreased, confirming that hypertension, when combined with age, increases cerebrovascular resistance and reduces cerebrovascular compliance. PMID:21708273

  4. Effects of chronic exposure to diluted automotive exhaust gas on the CNS of normotensive and hypertensive rats.

    Science.gov (United States)

    Roggendorf, W; Thron, N L; Ast, D; Köhler, P R

    1981-01-01

    Regarding the potential impact of traffic-born air pollutants on public health, attention during the last years has been increasingly focused on the possible effects in high-risk groups of the population. In order to evaluated this point further, the combined influence of both, chronic arterial hypertension and long-time exhaust gas exposure on the CNS has been studied. Both, normotensive Wistar) and spontaneously hypertensive rats (SHR) of either sex were exposed 5 X 8 hours per week for up to 18 months to atmospheres polluted by the emissions of an idling Otto engine with CO concentrations held constant at about 0,90 and 250 ppm, respectively. Biochemical data, body weight, and blood pressure were checked regularly. Characteristic histomorphological findings in the non-exposed SHR brains were hyalinosis and hyperplasia of intracerebral arterioles and -- in some cases -- small focal hemorrhages and infarcts. In the exposed SHR brains, large infarcts of the hemisphere and in the basal ganglia were found, which possibly corresponds to the increase of the mortality rate in SHR. We assume that the increase hematocrit plays an important role in the disturbance of microcirculation of the CNS.

  5. Prolonged water immersion. Effects on blood pressure maturation in normotensive rats.

    Science.gov (United States)

    Magrini, F; Reggiani, P; Ciulla, M; Meazza, R; Branzi, G

    1992-05-01

    The purpose of this experiment was to study the impact of simulated microgravity and of chronic removal of hydrostatic pressure gradients on blood pressure maturation and body growth in rats. A special device was developed in our laboratory to transfer prolonged "dry" water immersion (a technique that has been used for training astronauts under hypogravic conditions) to six Sprague-Dawley test rats (immersion-G group). The time course of heart rate, systolic blood pressure, urinary output, and body weight was monitored from weaning to maturity and then compared with those responses from six sex- and age-matched Sprague-Dawley rats grown in a gravity environment (group G). A downward shift in systolic blood pressure and body weight maturation curves was observed in immersion-G rats from the age of 60 days. Cessation of dry water immersion produced a gradual, significant rise in systolic blood pressure but not in body weight to control values. No marked changes in heart rate and urinary output between G and immersion-G rats were noticed throughout the investigation. Our results provide indirect evidence that an interference in the natural history of blood pressure maturation was introduced by immersion, which dissociated the effects of body weight increase during growth from the effects of ageing per se. It is concluded that the physiological increase in systolic blood pressure during growth is partly gravity-dependent.

  6. Role of candesartan against cerebral ischemia and oxidative damage in normotensive rats

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective Angiotensin Ⅱ(Ang Ⅱ)contributes to modulating blood pressure by stimulation of Ang Ⅱ AT1 receptors.We devised a rat transient middle cerebral artery occlusion(MCAO)model to assess whether oxidative damage is decreased after pretreatment with Angiotensin Ⅱ AT1 receptor blocker(ARB).Methods After 2 weeks pretreatment with ARB 0.5 and 1mg/kg,the male Wister rats were subjected to 2h middle cerebral artery occlusion(MCAO).At 24h,the lumen diameter of middle cerebral artery,the plasma level of 8-hydrox...

  7. Dynamic Modeling of Renal Blood Flow in Dahl Hypertensive and Normotensive Rats

    DEFF Research Database (Denmark)

    Knudsen, Torben; Elmer, H.; Knudsen, Morten;

    2004-01-01

    A method is proposed in this paper which allows characterisation of renal autoregulatory dynamics and efficiency using quantitative mathematical methods. Based on data from rat experiments, where arterial blood pressure and renal blood flow are measured, a quantitative model for renal blood flow ...

  8. Effect of chronic elevation of plasma calcium concentration by PTH or vitamin D3on blood pressure and hypotensive activity of nifedipine in rats

    NARCIS (Netherlands)

    Jonkman, F.A.M.; Thoolen, M.J.M.C.; Wilffert, B.

    1984-01-01

    The influence of a chronically elevated total plasma calcium concentration on blood pressure and heart rate was investigated in conscious normotensive rats. The plasma calcium concentration was elevated by continuous subcutaneous infusion with parathormone (PTH) after parathyreoidectomy, and by oral

  9. Cardiovascular effects of the essential oil of Croton zehntneri leaves in DOCA-salt hypertensive, conscious rats.

    Science.gov (United States)

    de Siqueira, Rodrigo José Bezerra; Duarte, Gloria Pinto; Magalhães, Pedro Jorge Caldas; Lahlou, Saad

    2013-08-01

    This study investigated the cardiovascular effects of the essential oil of Croton zehntneri (EOCZ) in deoxycorticosterone-acetate (DOCA)-salt hypertensive rats. Furthermore, in vitro experiments using isolated thoracic aortic rings were performed to assess the vascular effects of the EOCZ. In conscious hypertensive rats, intravenous (i.v.) injections of EOCZ (1-20 mg/kg) induced rapid (2-4 s) and dose-dependent hypotension and bradycardia (phase 1). The hypotension was followed by a significant pressor effect that was more evident at the higher doses (10 and 20 mg/kg) of EOCZ. Hypotension and bradycardia of EOCZ (phase 1) were abolished and respectively reversed into pressor and tachycardiac effects by methylatropine (1 mg/kg, i.v.) pretreatment. In isolated endothelium-intact aortic preparations, increasing concentrations (1-1000 microg/mL) of EOCZ relaxed the potassium-induced contraction in a concentration-dependent manner with an IC50 (geometric mean [95% confidence interval]) value of 202.0 [92.0-443.7] microg/mL. This vasorelaxant effect remained unaffected by either mechanical removal of functional vascular endothelium (IC50 = 189.0 [159.4-224.7] microg/mL) or the addition of atropine (1 microM) (IC50 = 158.6 [79.8-316.2] microg/mL) in the perfusion medium. These data show that i.v. administration of EOCZ in DOCA-salt hypertensive rats induces a vago-vagal reflex decreases in heart rate and blood pressure (phase 1). EOCZ may induce a second and delayed hypotension due to its direct endothelium-independent vasorelaxant effects, but it seems to be buffered by the pressor component (subsequent to phase 1) of EOCZ. This pattern of blood pressure and heart rate responses to EOCZ seems unaltered by DOCA-salt hypertension, as was similar to that previously reported in conscious normotensive rats.

  10. Consciousness

    OpenAIRE

    Terrence J Sejnowski

    2015-01-01

    No one did more to draw neuroscientists’ attention to the problem of consciousness in the twentieth century than Francis Crick, who may be better known as the co-discoverer (with James Watson) of the structure of DNA. Crick focused his research on visual awareness and based his analysis on the progress made over the last fifty years in uncovering the neural mechanisms underlying visual perception. Because much of what happens in our brains occurs below the level of consciousness and many of o...

  11. Consciousness

    OpenAIRE

    R. J. Aumann

    2005-01-01

    Consciousness is the last great frontier of science. Here we discuss what it is, how it differs fundamentally from other scientific phenomena, what adaptive function it serves, and the difficulties in trying to explain how it works. The emphasis is on the adaptive function.

  12. Sodium intake and renin system avtivity: Effects of metroprolol on the log-linear relationship in conscious rats

    DEFF Research Database (Denmark)

    Bie, Peter

    2011-01-01

    Sodium intake and renin system avtivity: Effects of metroprolol on the log-linear relationship in conscious rats.......Sodium intake and renin system avtivity: Effects of metroprolol on the log-linear relationship in conscious rats....

  13. β1-blockers lower norepinephrine release by inhibiting presynaptic, facilitating β1-adrenoceptors in normotensive and hypertensive rats

    Directory of Open Access Journals (Sweden)

    Torill eBerg

    2014-04-01

    Full Text Available Peripheral norepinephrine release is facilitated by presynaptic β-adrenoceptors (AR, believed to involve the β2-subtype exclusively. However, β1-selective blockers are the most commonly used β-blockers in hypertension. Here I tested the hypothesis that β1AR may function as presynaptic, release-facilitating auto-receptors. Since β1AR-blockers are injected during myocardial infarction, their influence on the cardiovascular response to acute norepinephrine release was also studied. By a newly established method, using tyramine-stimulated release through the norepinephrine transporter (NET, presynaptic control of catecholamine release was studied in normotensive and spontaneously hypertensive rats. β1AR-selective antagonists (CGP20712A, atenolol, metoprolol reduced norepinephrine overflow to plasma equally efficient as β2AR-selective (ICI-118551 and β1+2AR (nadolol antagonists in both strains. Neither antagonist lowered epinephrine secretion. Atenolol, which does not cross the blood-brain barrier, reduced norepinephrine overflow after adrenalectomy, adrenalectomy+ganglion blockade, losartan or nephrectomy. Atenolol and metoprolol reduced resting cardiac work load. During tyramine-stimulated norepinephrine release, they had little effect on work load, and increased the transient rise in total peripheral vascular resistance, particularly atenolol when combined with losartan. In conclusion, β1AR, like β2AR, stimulated norepinephrine but not epinephrine release, independent of adrenal catecholamines, ganglion transmission, or renal renin release/angiotensin AT1-receptor activation. β1AR therefore functioned as a peripheral, presynaptic, facilitating auto-receptor. Like tyramine, hypoxia may induce NET-mediated release. Augmented tyramine-induced vasoconstriction, as observed after injection of β1AR-blocker, particularly atenolol combined with losartan, may hamper organ perfusion, and may have clinical relevance in hypoxic conditions such as

  14. Alpha-Adrenergic receptors in cerebral microvessels of normotensive and spontaneously hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, H.; Wada, A.; Izumi, F.; Magnoni, M.S.; Trabucchi, M.

    1985-03-01

    In rat cerebral microvessels, we characterized alpha 1- and alpha 2-adrenergic receptors, using (/sup 3/H)prazosin and (/sup 3/H)-p-amino-clonidine as radioligands. (/sup 3/H)Prazosin binding to the cerebral microvessels was saturable and of high affinity (dissociation constant of 78 pM), with a maximum binding of 48 fmol/mg protein. (/sup 3/H)Prazosin binding reached equilibrium within 15 minutes and was dissociated by the addition of 10 microM phentolamine. The inhibitory effects of isomers of norepinephrine and epinephrine on the binding showed that l-isomers were over 10 times more potent than d-isomers. (/sup 3/H)-p-Amino-clonidine binding to the cerebral microvessels was saturable and of high affinity (K/sub D/ . 0.61 nM) with a B/sub max/ of 73 fmol/mg protein. The binding reached equilibrium within 30 minutes, and was dissociated by the addition of 100 microM l-norepinephrine. l-Isomers of norepinephrine and epinephrine were over 10 times more potent than d-isomers in displacing the binding. Thus, both (/sup 3/H)prazosin and (/sup 3/H)-p-amino-clonidine bindings to the cerebral microvessels were characterized by saturability, high affinity, reversibility, and stereo-specificity. Furthermore, the specificity of both binding sites was pharmacologically evaluated by the inhibitory effects of various adrenergic agonists and antagonists on the bindings. These data indicate the existence of alpha-adrenergic receptors in the cerebral microvessels and are consistent with the hypothesis that the cerebral microcirculation is regulated by adrenergic innervation. Furthermore, the receptors were measured in cerebral microvessels of spontaneously hypertensive rats and Wistar-Kyoto controls.

  15. Effects of 4-week administration of simvastatin in different doses on heart rate and blood pressure after metoprolol injection in normocholesterolaemic and normotensive rats.

    Science.gov (United States)

    Owczarek, Jacek; Jasińska, Magdalena; Wejman, Irena; Kurczewska, Urszula; Orszulak-Michalak, Daria

    2012-02-29

    Statins and β1-adrenergic antagonists are well established in cardiovascular events therapy and prevention. The previous study showed that statins might impact on β-adrenergic signalling and blood pressure in a dose-dependent manner. The aim of the study was to evaluate the impact of 4-week administration of simvastatin given at different doses on the heart rate and blood pressure after injection of metoprolol in rats. The experiments were performed in normocholesterolaemic and normotensive Wistar rats. Rats received simvastatin in doses of 1, 10 and 20 mg/kg body weight (bw) for 4 weeks. The control group received 0.2% methylcellulose. For the further estimation of the heart rate and blood pressure, metoprolol at 5 mg/kg bw or 0.9% NaCl was injected intraperitoneally. Simvastatin at doses of 1, 10 and 20 mg/kg bw did not influence the heart rate or blood pressure as compared to the control group. Metoprolol injection statistically significantly decreased the heart rate (439.29±14.03 min(-1) vs. 374.41±13.32 min(-1); pheart rate and blood pressure (mean, systolic, diastolic) were similar as compared to the group receiving metoprolol alone. Simvastatin administration during a 4-week period in different doses did not influence the heart rate or blood pressure after metoprolol injection in normocholesterolaemic and normotensive rats.

  16. Recording of intracranial pressure in conscious rats via telemetry.

    Science.gov (United States)

    Guild, Sarah-Jane; McBryde, Fiona D; Malpas, Simon C

    2015-09-01

    Although cerebral perfusion pressure (CPP) is known to be fundamental in the control of normal brain function, there have been no previous long-term measurements in animal models. The aim of this study was to explore the stability and viability of long-term recordings of intracranial pressure (ICP) in freely moving rats via a telemetry device. We also developed a repeatable surgical approach with a solid-state pressure sensor at the tip of the catheter placed under the dura and in combination with arterial pressure (AP) measurement to enable the calculation of CPP. Telemeters with dual pressure catheters were implanted in Wistar rats to measure ICP and AP. We found that the signals were stable throughout the 28-day recording period with an average ICP value of 6 ± 0.8 mmHg. Significant light-dark differences were found in AP (3.1 ± 2.7 mmHg, P = 0.02) and HR (58 ± 12 beats/min, P = 0.003), but not ICP (0.3 ± 0.2 mmHg, P >0.05) or CPP (2.6 ± 2.8 mmHg, P > 0.05). Use of kaolin to induce hydrocephalus in several rats demonstrates the ability to measure changes in ICP throughout disease progression, validating this new solution for chronic measurement of ICP, CPP, and AP in conscious rats. Copyright © 2015 the American Physiological Society.

  17. Aortic depressor nerve stimulation does not impede dynamic characteristics of the carotid sinus baroreflex in normotensive or spontaneously hypertensive rats.

    Science.gov (United States)

    Kawada, Toru; Turner, Michael J; Shimizu, Shuji; Fukumitsu, Masafumi; Kamiya, Atsunori; Sugimachi, Masaru

    2017-03-08

    Recent clinical trials in patients with drug-resistant hypertension indicate that electrical activation of the carotid sinus baroreflex (baroreflex activation therapy) can reduce arterial pressure (AP) for more than a year. To examine whether the electrical stimulation from one baroreflex system impedes normal short-term AP regulation via another unstimulated baroreflex system, we electrically stimulated the left aortic depressor nerve (ADN) while estimating the dynamic characteristics of the carotid sinus baroreflex in anesthetized normotensive Wistar-Kyoto (WKY, n=8) rats and spontaneously hypertensive rats (SHR, n=7). Isolated carotid sinus regions were perturbed for 20 min using a Gaussian white noise signal with a mean of 120 mmHg for WKY and 160 mmHg for SHR. Tonic ADN stimulation (2 Hz, 10 V, 0.1-ms pulse width) decreased mean sympathetic nerve activity (73.4±14.0 vs. 51.6±11.3 arbitrary units in WKY, P = 0.012; and 248.7±33.9 vs. 181.1±16.6 arbitrary units in SHR, P = 0.018) and mean AP (90.8±6.6 vs. 81.2±5.4 mmHg in WKY, P=0.004; and 128.6±9.8 vs. 114.7±10.3 mmHg in SHR, P = 0.009). The slope of dynamic gain in the neural arc transfer function from carotid sinus pressure to sympathetic nerve activity was not different between trials with and without the ADN stimulation (12.55±0.93 vs. 13.03±1.28 dB/decade in WKY, P = 0.542; and 17.37±1.01 vs. 17.47±1.64 dB/decade in SHR, P = 0.946). These results indicate that the tonic ADN stimulation does not significantly modify the dynamic characteristics of the carotid sinus baroreflex.

  18. Receptors involved in moxonidine-stimulated atrial natriuretic peptide release from isolated normotensive rat hearts.

    Science.gov (United States)

    Mukaddam-Daher, Suhayla; Menaouar, Ahmed; Gutkowska, Jolanta

    2006-07-10

    Imidazoline I1-receptors are present in the heart and may be involved in atrial natriuretic peptide (ANP) release. The following studies investigated whether moxonidine (an antihypertensive imidazoline I1-receptor and alpha2-adrenoceptor agonist) acts directly on the heart to stimulate ANP release, and to characterize the receptor type involved in this action. Perfusion of rat (200-225 g) isolated hearts with moxonidine (10(-6) and 10(-5) M), for 30 min, resulted in ANP release (83+/-29 and 277+/-70 ng/30 min, above basal, respectively), significantly (Palpha1-adrenoceptors), and prazosin (alpha1>alpha2-adrenoceptors), but increased by rauwolscine (alpha2-adrenoceptors). Perfusion with 10(-5) M brimonidine (full alpha2-adrenoceptor agonist) inhibited moxonidine-stimulated ANP release. Similarly, moxonidine (10(-6) M) tended to reduce coronary flow, but significantly increased coronary flow in the presence of brimonidine, which was vasoconstrictive when perfused alone. Coronary flow was reduced by 10(-5) M each, brimonidine>clonidine>moxonidine; while similar bradycardia was observed with clonidine and moxonidine, but not with brimonidine. In conclusion, these results argue in favor of moxonidine acting primarily on imidazoline I1-receptors to release ANP, with both alpha2-adrenoceptor and imidazoline I1-receptors exerting inhibitory inter-relation. In contrast, the coronary vasodilatory effect of moxonidine requires full activation of alpha2-adrenoceptor. The sympatholytic and ANP-releasing effects of moxonidine appear to be mediated by cardiac imidazoline receptors that may be differentially localized. Most importantly, moxonidine can stimulate ANP release from the heart without contribution of the central nervous system.

  19. Effects of nonhypotensive endotoxemia in conscious rats: Role of prostaglandins

    Energy Technology Data Exchange (ETDEWEB)

    Burnier, M.; Waeber, B.; Aubert, J.F.; Nussberger, J.; Brunner, H.R. (Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland))

    1988-03-01

    A nonhypotensive dose of endotoxin was administered to normal conscious rats to evaluate the vascular and humoral effects of endotoxemia per se. Mean blood pressure and heart rate remained stable during the 45 min infusion of Escherichia coli endotoxin. However, a marked increase in plasma renin activity plasma epinephrine and plasma norepinephrine was observed during infusion in endotoxin-treated rats when compared with the vehicle-treated animals. In addition, the blood pressure response to exogenous norepinephrine was significantly reduced during nonhypotensive endotoxemia. Significant changes in regional blood flow distribution, as assessed by radiolabeled microspheres, were observed in endotoxemic rats; in particular a decrease in renal blood flow, and an increase in coronary blood flow were found. The role of prostaglandins in the vascular and humoral alterations induced by nonhypotensive endotoxemia was also examined. Pretreatment with indomethacin (5 mg) prevent the increase in plasma renin activity as well as plasma catecholamine levels. On the contrary, the decreased vascular reactivity and the reduction in renal blood flow observed during endotoxemia were not affected by prostaglandin synthesis inhibition. Thus significant vascular and humoral changes have been found during endotoxemia even in absence of hypotension. The humoral but not the vascular effects of endotoxemia were abolished when prostaglandin synthesis was inhibited.

  20. Vascular Tone Regulation Induced by C-Type Natriuretic Peptide: Differences in Endothelium-Dependent and -Independent Mechanisms Involved in Normotensive and Spontaneously Hypertensive Rats

    Science.gov (United States)

    Caniffi, Carolina; Cerniello, Flavia M.; Gobetto, María N.; Sueiro, María L.; Arranz, Cristina

    2016-01-01

    Given that the role of C-type natriuretic peptide (CNP) in the regulation of vascular tone in hypertensive states is unclear, we hypothesized that impaired response of the nitric oxide system to CNP in spontaneously hypertensive rats (SHR) could affect vascular relaxation induced by the peptide in this model of hypertension, and that other endothelial systems or potassium channels opening could also be involved. We examined the effect of CNP on isolated SHR aortas, and the hindlimb vascular resistance (HVR) in response to CNP administration compared to normotensive rats. Aortas were mounted in an isometric organ bath and contracted with phenylephrine. CNP relaxed arteries in a concentration-dependent manner but was less potent in inducing relaxation in SHR. The action of CNP was diminished by removal of the endothelium, inhibition of nitric oxide synthase by Nω-nitro-L-arginine methyl ester, and inhibition of soluble guanylyl cyclase by 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one in both groups. In contrast, blockade of cyclooxygenase or subtype 2 bradykinin receptor increased CNP potency only in SHR. In both Wistar and SHR, CNP relaxation was blunted by tetraethylammonium and partially inhibited by BaCl2 and iberiotoxin, indicating that it was due to opening of the Kir and BKCa channels. However, SHR seem to be more sensitive to Kir channel blockade and less sensitive to BKCa channel blockade than normotensive rats. In addition, CNP decreases HVR in Wistar and SHR, but the effect of CNP increasing blood flow was more marked in SHR. We conclude that CNP induces aorta relaxation by activation of the nitric oxide system and opening of potassium channels, but the response to the peptide is impaired in conductance vessel of hypertensive rats. PMID:27936197

  1. Intercostal muscle motor behavior during tracheal occlusion conditioning in conscious rats

    Science.gov (United States)

    Jaiswal, Poonam B.

    2016-01-01

    A respiratory load compensation response is characterized by increases in activation of primary respiratory muscles and/or recruitment of accessory respiratory muscles. The contribution of the external intercostal (EI) muscles, which are a primary respiratory muscle group, during normal and loaded breathing remains poorly understood in conscious animals. Consciousness has a significant role on modulation of respiratory activity, as it is required for the integration of behavioral respiratory responses and voluntary control of breathing. Studies of respiratory load compensation have been predominantly focused in anesthetized animals, which make their comparison to conscious load compensation responses challenging. Using our established model of intrinsic transient tracheal occlusions (ITTO), our aim was to evaluate the motor behavior of EI muscles during normal and loaded breathing in conscious rats. We hypothesized that 1) conscious rats exposed to ITTO will recruit the EI muscles with an increased electromyogram (EMG) activation and 2) repeated ITTO for 10 days would potentiate the baseline EMG activity of this muscle in conscious rats. Our results demonstrate that conscious rats exposed to ITTO respond by recruiting the EI muscle with a significantly increased EMG activation. This response to occlusion remained consistent over the 10-day experimental period with little or no effect of repeated ITTO exposure on the baseline ∫EI EMG amplitude activity. The pattern of activation of the EI muscle in response to an ITTO is discussed in detail. The results from the present study demonstrate the importance of EI muscles during unloaded breathing and respiratory load compensation in conscious rats. PMID:26823339

  2. Magnolol administration in normotensive young spontaneously hypertensive rats postpones the development of hypertension: role of increased PPAR gamma, reduced TRB3 and resultant alleviative vascular insulin resistance.

    Directory of Open Access Journals (Sweden)

    Xiangyan Liang

    Full Text Available Patients with prehypertension are more likely to progress to manifest hypertension than those with optimal or normal blood pressure. However, the mechanisms underlying the development from prehypertension to hypertension still remain largely elusive and the drugs for antihypertensive treatment in prehypertension are absent. Here we determined the effects of magnolol (MAG on blood pressure and aortic vasodilatation to insulin, and investigated the underlying mechanisms. Four-week-old male spontaneous hypertensive rats (SHR and age-matched normotensive Wistar-Kyoto (WKY control rats were used. Our results shown that treatment of young SHRs with MAG (100 mg/kg/day, o.g. for 3 weeks decreased blood pressure, improved insulin-induced aorta vasodilation, restored Akt and eNOS activation stimulated by insulin, and increased PPARγ and decreased TRB3 expressions. In cultured human umbilical vein endothelial cells (HUVECs, MAG incubation increased PPARγ, decreased TRB3 expressions, and restored insulin-induced phosphorylated Akt and eNOS levels and NO production, which was blocked by both PPARγ antagonist and siRNA targeting PPARγ. Improved insulin signaling in HUVECs by MAG was abolished by upregulating TRB3 expression. In conclusion, treatment of young SHRs with MAG beginning at the prehypertensive stage decreases blood pressure via improving vascular insulin resistance that is at least partly attributable to upregulated PPARγ, downregulated TRB3 and consequently increased Akt and eNOS activations in blood vessels in SHRs.

  3. Influence of dosage, consciousness, and nifedipine on the acute pressor response to intraperitoneally administered cadmium. [Rats

    Energy Technology Data Exchange (ETDEWEB)

    Hall, C.E.; Hungerford, S.

    1982-05-01

    The acute pressor effect of intraperitoneally administered cadmium was explored over the dose range 0.015-2 mg/kg in both pentobarbital-anesthetized and conscious rats. The former first respondent at 0.031 mg/kg, and successive doublings of that dosage increased the highest pressures attained in a stepwise fashion until a dosage of 0.25 mg/kg, the maximally effective quantity, was reached. Arterial pressure did not rise in conscious rats until a dose of 1 mg/kg, which gave the maximum response within the range examined. Heart-rate changes with Cd were slight, and rarely significant at a given dosage, but pentobarbital invariably caused tachycardia. Anesthetized rats thus gave a graded response, while conscious animals reacted in an all-or-none fashion. The increased pressor responsiveness of rats under pentobarbital can not be ascribed to its cardiac parasympatholytic effects, since sensitivity was not conferred upon conscious rats when pretreated with atropine at a dose producing even greater tachycardia than that caused by pentobarbital. Nifedipine, which blocks calcium entry into smooth muscle cells, prevented the pressor response to cadmium when given as pretreatment and terminated an ongoing response when give intercurrently. Possible mechanisms to account for the observed behavior are considered.

  4. Effects of music composed by Mozart and Ligeti on blood pressure and heart rate circadian rhythms in normotensive and hypertensive rats.

    Science.gov (United States)

    Lemmer, Björn

    2008-11-01

    There is continuing discussion on the effect of music ("Mozart effect") on numerous functions in man and experimental animals. Radiotelemetry now allows one to monitor cardiovascular functions in freely-moving unrestrained experimental animals. Radiotelemetry was used to monitor systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), and motor activity (MA) in male normotensive WKY and hypertensive SHR animals. Rats were synchronized to a 12 h light (L): 12 h dark (D) regimen in an isolated, ventilated, light-controlled, sound-isolated animal container. Music (Mozart, Symphony # 40; Ligeti, String Quartet # 2) were played for 2 h at 75 dB in the animal cabin starting at the onset of L or D in a cross-over design. Data were collected every 5 min for 24 h under control conditions and during and after music. In addition, plasma concentrations of norepinephrine (NE) were determined in unrestrained animals at 3 h intervals over 24 h. In both WKY and SHR, highly significant circadian rhythms were obtained in SBP, DBP, HR, and MA under control conditions; HR was lower and BP higher in SHR than in WKY. NE was circadian rhythmic in both strains with higher values in D; the increase in NE with immobilization was much more pronounced in SHR than in WKY. The music of Mozart had no effect on either parameter in WKY, neither in L nor in D. In contrast, in SHR, the music of Mozart presented in L significantly decreased HR and left BP unaffected, leading to a small decrease in cardiac output. The music of Ligeti significantly increased BP both in L and in D and reflexively reduced HR in L, the effects being long-lasting over 24 h. Interestingly, white noise at 75 dB had no effect at all on either function in both strains. The effects of both Mozart and Ligeti cannot be attributed to a stress reaction, as stress due to cage switch increased HR and BP both in WKY and SHR. The study clearly demonstrates that music of different character (tempo, rhythm, pitch, tonality) can

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

    OpenAIRE

    Ibrahim M. Salman; Divya Sarma Kandukuri; Joanne Lesley Harrison; Cara Margaret Hildreth; Jacqueline Kathleen Phillips

    2015-01-01

    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...

  6. Two useful methods for evaluating antihypertensive drugs in conscious freely moving rats

    Institute of Scientific and Technical Information of China (English)

    Ding-feng SU; Li-ping XU; Chao-yu MIAO; He-hui XIE; Fu-ming SHEN; Yuan-ying JIANG

    2004-01-01

    AIM: Computerized analysis of blood pressure in conscious freely moving rats is a sound technique for physiological and pharmacological studies. The present work, based on this technique, was designed to introduce two useful methods for the evaluation of antihypertensive drugs in conscious spontaneously hypertensive rat (SHR). They were the directly intragastric administration of drugs and modified probability sum test for evaluating the synergism of the combination of two drugs. METHODS AND RESULTS: (1) Directly intragastric administration was used in conscious rats. A catheter was inserted into stomach immediately after arterial catheter insertion. Three days after operation, blood pressure was recorded and drug might be given intragastically via the gastric catheter. (2) Modified probability sum test was used to evaluate the synergism of two drugs. The formula was: q=PA+B/(PA+PB-PA×PB).With this method, it was obtained: q= 1.32 for the effects of the combination of atenolol and nitrendipine (20 mg/kg+ 10 mg/kg) on systolic blood pressure; q=1.41 for the effects of the combination of atenolol and amlodipine (10 mg/kg+l mg/kg) on systolic blood pressure. CONCLUSION: The two methods introduced by the present work will be important and useful for antihypertensive drug evaluation in conscious freely moving rats.

  7. Vitamin D3 deficiency increases DNA damage and modify the expression of genes associated with hypertension in normotensive and hypertensive rats

    Directory of Open Access Journals (Sweden)

    Carla Silva Machado

    2015-05-01

    Full Text Available Vitamin D3 is a lipophilic micronutrient obtained from the diet (salmon, sardines, mackerel and cod liver oil or by the conversion of 7-dehydrocholesterol on skin after exposure to UVB radiation. This vitamin participates in several cellular processes, contributes to the maintenance of calcium concentrations, acts on phosphorus absorption, and is also related to the development and progression of chronic diseases. In hypertension, it is known that vitamin D3 act on renin-angiotensin-aldosterone system, regulates the gene expression and can induce or attenuate oxidative DNA damage. Vitamin D3 deficiency is present in 30-50% of human population (Pilz et al., 2009, and has been associated with increase of chromosomal instability and DNA damage (Nair-Shalliker; Armstrong; Fenech, 2012. Since experimental and clinical studies have suggested a relationship between vitamin D3 and blood pressure, the aim of this study was to evaluate whether vitamin D3 deficiency or supplementation lead to an increase or decrease in DNA damage, regulates the expression of genes associated with hypertension and changes the systolic blood pressure. Spontaneously hypertensive rats (SHR, used as a model of human essential hypertension, and their normotensive controls (Wistar Kyoto – WKY were fed a control diet (vitamin D3 at 1.000 UI/kg, a deficient diet (vitamin D3 at 0 UI/kg or a supplemented diet (vitamin D3 at 10.000 UI/kg for 12 weeks. DNA damage was assessed by comet assay in cardiac muscle tissue and blood tissue, following the methodology proposed by Singh et al. (1988 and Tice et al. (2000; gene expression of 84 genes was assessed by RT2ProfilerTM PCR Array in cardiac muscle tissue; and systolic blood pressure was measured weekly by a noninvasive method using tail plethysmography. In SHR and WKY rats, vitamin D3 deficiency increased DNA damage in the blood tissue and did not change the DNA damage in cardiac muscle tissue; vitamin D3 supplementation maintained the

  8. Possible mechanisms of action of the aqueous extract of Artocarpus altilis (breadfruit) leaves in producing hypotension in normotensive Sprague-Dawley rats.

    Science.gov (United States)

    Nwokocha, Chukwuemeka R; Owu, Daniel U; McLaren, Michca; Murray, JeAnn; Delgoda, Rupika; Thaxter, Karen; McCalla, Garsha; Young, Lauriann

    2012-09-01

    Artocarpus altilis (Parkinson) Fosberg (Moraceae) (breadfruit) leaves are used as an antihypertensive remedy. We investigated the possible mechanisms of action of its aqueous extract and its effect on cytochromes P450 (CYP) enzyme activities. Intravenous administration of an aqueous leaf extract (20.88-146.18 mg/kg) of A. altilis on mean arterial pressure and heart rate were recorded via cannulation of the carotid artery on anaesthetized normotensive Sprague-Dawley rats. Recordings of the contractile activity of the aortic rings to the extract (0.71-4.26 mg/mL) were studied using standard organ bath techniques. Inhibitions of human CYP3A4 and CYP2D6 enzyme activities were evaluated by means of a fluorometric assay in 96 well plates using heterologously expressed microsomes. A. altilis caused significant (p altilis exhibits negative chronotropic and hypotensive effects through α-adrenoceptor and Ca²⁺ channel antagonism. Drug adversity effects are unlikely if the aqueous leaf extract is consumed with other medications reliant on CYP3A4 and CYP2D6 metabolism. This study thus provides scientific evidence for the use of the breadfruit in the treatment of hypertension.

  9. Effects of the selective β1-adrenoceptor antagonist, nebivolol, on cardiovascular parameters in the pithed normotensive rat

    NARCIS (Netherlands)

    Schneider, J.; Fruh, C.; Wilffert, B.; Peters, Thies

    1990-01-01

    In the pithed rat we investigated the cardiovascular properties of d,l-nebivolol and its enantiomers. We used the increase in heart rate elicited by (-)-adrenaline and (-)-noradrenaline as a model for studying β1-adrenoceptors. A leftward shift of the logarithmic dose-pressor response curve of (-)-a

  10. Extrasynaptic location of alpha-2 and noninnervated beta-2 adrenoceptors in the vascular system of the pithed normotensive rat

    NARCIS (Netherlands)

    Wilffert, B.; Timmermans, P.B.M.W.M.; Van Zwieten, P.A.

    1982-01-01

    The receptors involved in the pressor and tachycardic effects of catecholamines applied systemically or released from sympathetic nerve endings were compared. Intravenously administered (-)-epinephrine activated alpha-1, alpha-2, beta-1 and beta-2 adrenoceptors as demonstrated in pithed rats, using

  11. Delivery of sry1, but not sry2, to the kidney increases blood pressure and sns indices in normotensive wky rats

    Directory of Open Access Journals (Sweden)

    Hart Mike

    2009-06-01

    Full Text Available Abstract Background Our laboratory has shown that a locus on the SHR Y chromosome increases blood pressure (BP in the SHR rat and in WKY rats with the SHR Y chromosome (SHR/y rat. A candidate for this Y chromosome hypertension locus is Sry, a gene that encodes a transcription factor responsible for testes determination. The SHR Y chromosome has six divergent Sry loci. The following study examined if exogenous Sry1 or Sry2 delivered to the kidney would elevate renal tyrosine hydroxylase, renal catecholamines, plasma catecholamines and telemetered BP over a 28 day period. We delivered 50 μg of either the expression construct Sry1/pcDNA 3.1, Sry2/pcDNA 3.1, or control vector into the medulla of the left kidney of normotensive WKY rats by electroporation. Weekly air stress was performed to determine BP responsiveness. Separate groups of animals were tested for renal function and plasma hormone patterns and pharmacological intervention using alpha adrenergic receptor blockade. Pre-surgery baseline and weekly blood samples were taken from Sry1 electroporated and control vector males for plasma renin, aldosterone, and corticosterone. BP was measured by telemetry and tyrosine hydroxylase and catecholamines by HPLC with electrochemical detection. Results In the animals receiving the Sry1 plasmid there were significant increases after 21 days in resting plasma norepinephrine (NE, 27% and renal tyrosine hydroxylase content (41%, p Sry1 (143 mmHg, p Sry1 (41 mmHg compared to controls (28 mmHg, p Sry2 did not elevate BP or SNS indices and further tests were not done. The hormone profiles for plasma renin, aldosterone, and corticosterone between electroporated Sry1 and control vector males showed no significant differences over the 28 day period. Alpha adrenergic receptor blockade prevented the air stress pressor response in both strains. Urinary dopamine significantly increased after 7 days post Sry electroporation. Conclusion These results are consistent

  12. Comparative effects of indomethacin and nabumetone on urine and electrolyte output in conscious rats.

    Science.gov (United States)

    bin Long, Idris; Singh, Harbindar Jeet; Rao, Gurubelli Janardhana

    2005-11-01

    The effects of indomethacin and nabumetone on urine and electrolyte excretion in conscious rats were examined. Male Sprague-Dawley rats were housed individually for a five-week duration, consisting of acclimatization, control, experimental, and recovery phases. During the experimental phase, rats were given either indomethacin (1.5 mg . kg(-1) body weight . day(-1) in 0.5 ml saline, n = 10), nabumetone (15 mg . kg(-1) body weight . day(-1) 0.5 ml saline, n = 10), or 0.5 ml saline alone (n = 10) for a period of two weeks. Water and food intake, body weight, urine output, and electrolyte excretions were estimated. Data were analyzed using two-way ANOVA. Urine output in the indomethacin- and nabumetone-treated groups was not different from the controls, but was significantly different between the drug-treated groups (Pnabumetone-treated and control rats. However, sodium and potassium excretion was significantly lower in rats receiving indomethacin when compared to the control rats. Calcium and magnesium outputs, although did not differ from the controls, nevertheless decreased significantly with indomethacin (Pnabumetone when given at maximum human therapeutic doses may affect urine and electrolyte output in conscious rats.

  13. In vivo hemodynamic and electrocardiographic changes following Crataegus aronia syn. Azarolus L administration to normotensive Wistar rats.

    Science.gov (United States)

    Shatoor, Abdullah S

    2013-02-01

    To evaluate the effects of the whole plant aqueous extract of Crataegus aronia (C. aronia) syn. Azarolus (L) on the hemodynamic and electrocardiographic intervals in albino rats. This study was carried out in 2 stages at the Research Laboratory, Physiology Department, Medical College of King Khalid University, Abha, Kingdom of Saudi Arabia between February and June 2012. First, the effects of C. aronia syn. Azarolus (L) on the hemodynamics and electrocardiograph in 54 Wistar male rats were assessed, then the mechanisms underlying the hemodynamic and electrocardiographic changes observed in the first stage were evaluated in 48 rats of the same species. The C. aronia administered at escalating doses (0.05-20 microgram/kg) produced a dose-time-dependent decrease in heart rate (HR) and mean arterial pressure (MAP). Higher doses (15 and 20 microgram/kg) produced the most significant reduction in both HR and MAP, and induced sinus node suppression and progressive atrio-ventricular blockade. The underlying mechanism of the induced bradyarrhythmia appeared to be due to the direct stimulation of the muscarinic receptor M2 and possible blockade of beta-receptors, while the hypotension was caused by enhanced nitric oxide release. No significant alterations in the electrocardiogram (ECG) components were observed. The administration of the C. aronia syn. Azarolus extract induced bradyarrhythmia and hypotension, without alteration in the ECG components.

  14. Simultaneous pulmonary and systemic blood pressure and ECG Interval measurement in conscious, freely moving rats.

    Science.gov (United States)

    Rey, Markus; Weber, Edgar W; Hess, Patrick D

    2012-03-01

    Here we evaluated the ability of a new, dual blood-pressure telemetry transmitter to simultaneously measure pulmonary and systemic blood pressure and the electrocardiogram in rats. The transmitter was implanted in normotensive and monocrotaline-induced pulmonary hypertensive Wistar rats, with sensing catheters placed in the pulmonary artery (channel 1) and descending aorta (channel 2). Biopotential electrodes were positioned to record an apex-based lead II electrocardiogram. Pulmonary and systemic arterial blood pressure and electrocardiographic waveforms were recorded between 2 and 12 wk after implantation of the transmitter. During this period, pulmonary arterial pressure progressively increased in monocrotaline-treated compared with saline-treated rats. The pharmacologic response of rats to reference compounds was measured by using the transmitter to validate the technique and to evaluate the ability of the device to transmit changes in blood pressure and the electrocardiogram. Validation against 2 Millar high-fidelity blood-pressure catheters confirmed the accuracy of the blood pressure data recorded with the transmitter. In addition, local tolerance of the associated catheters was confirmed by histologic examination.

  15. Comparative Analysis of Renin-Angiotensin System (RAS)-Related Gene Expression Between Hypertensive and Normotensive Rats

    Science.gov (United States)

    Williamson, Chad R.; Khurana, Sandhya; Nguyen, Phong; Byrne, Collin J.; Tai, T.C.

    2017-01-01

    Background The renal renin-angiotensin system (RAS) is physiologically important for blood pressure regulation. Altered regulation of RAS-related genes has been observed in an animal model of hypertension (spontaneously hypertensive rats – SHRs). The current understanding of certain RAS-related gene expression differences between Wistar-Kyoto rats (WKYs) and SHRs is either limited or has not been compared. The purpose of this study was to compare the regulation of key RAS-related genes in the kidneys of adult WKYs and SHRs. Material/Methods Coronal sections were dissected through the hilus of kidneys from 16-week-old male WKYs and SHRs. RT-PCR analysis was performed for Ace, Ace2, Agt, Agtr1a, Agtr1b, Agtr2, Atp6ap2 (PRR), Mas1, Ren, Rnls, and Slc12a3 (NCC). Results Increased mRNA expression was observed for Ace, Ace2, Agt, Agtr1a, Agtr1b, and Atp6ap2 in SHRs compared to WKYs. Mas1, Ren, Slc12a3, and Rnls showed no difference in expression between animal types. Conclusions This study shows that the upregulation of several key RAS-related genes in the kidney may account for the increased blood pressure of adult SHRs. PMID:28138124

  16. [Effect of somatostatin on the hemodynamic changes induced by acute experimental pancreatitis in the conscious rat].

    Science.gov (United States)

    Ais, G; Novo, C; Ortega, M; González, A; Jiménez, I; López, J; Romeo, J M

    1994-03-01

    The aim of this study was to determine the hemodynamic effect of somatostatin, either prophylactically or therapeutically, in shock caused by acute necrohemorragic pancreatitis in conscious rats. For this purpose, radioactive microspheres were used in 3 groups (control pancreatitis, therapeutic somatostatin and prophylactic somatostatin), performing a basal and final hemodynamic study. In the control group, acute necrohemorragic pancreatitis resulted in overwhelming shock with decrease of 55% in cardiac output, 58% in renal blood flow, increase in total peripheral resistances of 342%, and death after 70 min. Therapeutic somatostatin decreased cardiac output by 42%, renal blood flow by 47%, and increased total peripheral resistances by 153%. Prophylactic somatostatin decreased cardiac output by 24%, and renal blooded flow by 28%; it increased peripheral resistances by 146%, and improved survival up to 97 min. In conclusion, therapeutic somatostatin, and particularly prophylactic somatostatin, improved hemodynamic shock after acute necrohemorragic pancreatitis in conscious rats.

  17. The susceptibility of ventricular arrhythmia to aconitine in conscious Lyon hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    Min LI; Jin WANG; He-hui XIE; Fu-ming SHEN; Ding-feng SU

    2007-01-01

    Aim: The present work was designed to investigate the relationship between hemodynamic parameters and the susceptibility of ventricular arrhythmia to aconitine in conscious Lyon hypertensive rats (LH). Methods: Male LH and Lyon low blood pressure rats (LL) were used. After the determination of baroreflex sensitivity (BRS), ventricular arrhythmia was induced by aconitine infusion inconscious rats. Blood pressure (BP) was recorded during the period of infusion. Results: Compared with the LL rats, the LH rats possessed significantly higher BP, blood pressure variability and lower BRS. The threshold of aconitine required for ventricular fibrillation and cardiac arrest in the LH rats were significantly lower than those in the LL rats. It was found that all the hemodynamic parameters studied were not correlated with the tl~eshold of aconitine required for arrhythmia, with the exception of BRS, which was positively related to the threshold of aconitine required for ventricular premature beat. Conclusion: The LH rats possessed greater susceptibility to aconitine-induced ventricular arrhythmias when compared to the LL rats. This greater susceptibility could not be attributed to anyone of the hemodynamic parameters alone studied in the LH rats. It is proposed that various hypertension-associated abnormalities, including the abnormal hemodynamics, may co-contribute to this vulnerability to ventricular arrhythmias.

  18. Tianeptine prevents respiratory depression without affecting analgesic effect of opiates in conscious rats.

    Science.gov (United States)

    Cavalla, David; Chianelli, Fabio; Korsak, Alla; Hosford, Patrick S; Gourine, Alexander V; Marina, Nephtali

    2015-08-15

    Respiratory depression remains an important clinical problem that limits the use of opiate analgesia. Activation of AMPA glutamate receptors has been shown to reverse fentanyl-induced respiratory changes. Here, we explored whether tianeptine, a drug known for its ability to phosphorylate AMPA receptors, can be used to prevent opiate-induced respiratory depression. A model of respiratory depression in conscious rats was produced by administration of morphine (10mg/kg, i.p.). Rats were pre-treated with test compounds or control solutions 5min prior to administration of morphine. Respiratory activity was measured using whole-body plethysmography. In conscious animals, tianeptine (2 and 10mg/kg, ip) and DP-201 (2-(4-((3-chloro-6-methyl-5,5-dioxido-6,11-dihydrodibenzo[c,f][1,2] thiazepin-11-yl)amino)butoxy)acetic acid; tianeptine analogue; 2mg/kg, ip) triggered significant (~30%) increases in baseline respiratory activity and prevented morphine-induced respiratory depression. These effects were similar to those produced by an ampakine CX-546 (15mg/kg, ip). The antinociceptive effect of morphine (hot plate test) was unaffected by tianeptine pre-treatment. In conclusion, the results of the experiments conducted in conscious rats demonstrate that systemic administration of tianeptine increases respiratory output and prevents morphine-induced respiratory depression without interfering with the antinociceptive effect of opiates.

  19. Neurotoxicity and toxicokinetics of norfloxacin in conscious rats

    Institute of Scientific and Technical Information of China (English)

    ZHANGLi-Rong; WANGYong-Ming; CHENBin-Yan; CHENGNeng-Neng

    2003-01-01

    AIM:To study the neurotoxicity and toxicokinetics of norfloxacin (NFLX) in freely moving rats. METHODS: Rats were assigned randomly to four treatment groups that received a single iv dose of 50, 100, 200 mg/kg of NFLX and 0.9% saline, respectively. Electroencephalogram (EEG) was continuously recorded with a computerized system in freely moving rats. Venous blood samples were collected for determination of the NFLX concentration by microbioassay method with Escherichia coli 441102 as the test strain. Toxicokinetic parameters were determined from serum concentration-time data with the 3p97 program. RESULTS: (1) The epileptiform discharges appeared in all NFLX groups with different latent periods, accompanied with limb twitching and clonictonic seizures. The relative total power of the EEG increased. (2) Drug serum concentration-time curves of different doses conformed to a two-compartmental model. The values of clearance, volume of distribution, and terminal half-life were dose-independent, while maximum serum concentrations(Cmax) and the areas under the concentration-time curve (AUC0→∞) of NFLX increased with dosage. (3) The relative total powers of EEG were lished a suitable approach to quantitatively determine central nervous system (CNS) stimulant effect of NFLX. There is a significant correlation between AUC0→∞ and the changes of relative total power, which may serve as the index for judgement and prediction of the CNS toxic effect induced by NFLX.

  20. Measurement of glomerular filtration rate in the conscious rat.

    Science.gov (United States)

    Pestel, Sabine; Krzykalla, Volker; Weckesser, Gerhard

    2007-01-01

    Glomerular filtration rate (GFR) is an important parameter for studying drug-induced impairments on renal function in rats. The GFR is calculated from the concentration of creatinine and blood urea nitrogen (BUN) in serum and in urine, respectively. Following current protocols serum and urine samples must be taken from the same animal. Thus, in order to determine time-dependent effects it is necessary to use for each time point one separated group of animals. We developed a statistical test which allows analyzing the GFR from two different groups of animals: one used for repeated serum and the other one used for repeated urine analysis. Serum and urine samples were taken from two different sets of rats which were otherwise treated identically, i.e. drug doses, routes of administration (per os or per inhalation) and tap water loading. For each dose group GFR mean, standard deviation and statistical analysis to identify differences between the dose groups were determined. After determination of the optimal time points for measurements, the effect on GFR of the three reference compounds, furosemide, hydrochlorothiazide and formoterol, was calculated. The results showed that the diuretic drugs furosemide and hydrochlorothiazide decreased the GFR and the antidiuretic drug formoterol increased the GFR, as counter regulation on urine loss or urine retention, respectively. A mathematical model and the corresponding algorithm were developed, which can be used to calculate the GFR, and to test for differences between groups from two separated sets of rats, one used for urine, and the other one for serum analysis. This new method has the potential to reduce the number of animals needed and to improve the quality of data generated from various groups of animals in renal function studies.

  1. An improved strategy for evaluating the extent of chronic arterial baroreceptor denervation in conscious rats

    Directory of Open Access Journals (Sweden)

    M. Rodríguez-Martínez

    2010-11-01

    Full Text Available There is no index or criterion of aortic barodenervation, nor can we differentiate among rats that have suffered chronic sham, aortic or sino-aortic denervation. The objective of this study was to develop a procedure to generate at least one quantitative, reproducible and validated index that precisely evaluates the extent of chronic arterial barodenervation performed in conscious rats. Data from 79 conscious male Wistar rats of about 65-70 days of age with diverse extents of chronic arterial barodenervation and used in previous experiments were reanalyzed. The mean arterial pressure (MAP and the heart rate (HR of all rats were measured systematically before (over 1 h and after three consecutive iv bolus injections of phenylephrine (PHE and sodium nitroprusside (SNP. Four expressions of the effectiveness of barodenervation (MAP lability, PHE ratio, SNP ratio, and SNP-PHE slope were assessed with linear fixed models, three-level average variance, average separation among levels, outlier box plot analysis, and overlapping graphic analysis. The analysis indicated that a neither MAP lability nor SNP-PHE slope was affected by the level of chronic sodium intake; b even though the Box-Cox transformations of both MAP lability [transformed lability index (TLI] and SNP-PHE slope [transformed general sensitivity index (TGSI, {((3-(ΔHRSNP-ΔHRPHE/ΔMAPSNP-ΔMAPPHE-0.4-1/-0.04597}] could be two promising indexes, TGSI proved to be the best index; c TLI and TGSI were not freely interchangeable indexes for this purpose. TGSI ranges that permit differentiation between sham (10.09 to 11.46, aortic (8.40 to 9.94 and sino-aortic (7.68 to 8.24 barodenervated conscious rats were defined.

  2. Microvascular responses to body tilt in cutaneous maximus muscle of conscious rats

    Science.gov (United States)

    Puri, Rohit K.; Segal, Steven S.

    1994-01-01

    We investigated microvascular responses to head-up tilt (HUT) and head-down tilt (HDT) in striated muscle of conscious male rats. To observe the microcirculation in the cutaneous maximus muscle, a transparent polycarbonate chamber was implanted aseptically into a skin fold created between the shoulders. Rats were trained to sit quietly during HUT and HDT while positioned on a horizontal microscope that rotated in the sagittal plane. At 4-5 days after surgery, arteriole and venule diameters were recorded using videomicroscopy while the rat experienced 10 min each (in random order) of HUT or HDT at 20 deg or 40 deg separated by 2-h rest periods. HUT had no affect on microvessel diameter; 20 deg HDT had little affect. In response to 40 deg HDT, 'large' arterioles constricted by 18 +/- 2% and 'small' arterioles dilated by 21 +/- 3%; this difference suggested variation in mechanisms controlling arteriolar responses. Venules exhibited a larger fluctuation in diameter during 40 deg HDT compared with other body positions, suggesting that venomotor activity may be induced with sufficient fluid shift or change in central venous pressure. These observations illustrate a viable model for studying microvascular responses to gravitational stress in conscious rats.

  3. A novel method to assess gastric accommodation and peristaltic motility in conscious rats.

    Science.gov (United States)

    Janssen, Pieter; Nielsen, Maria Astin; Hirsch, Ika; Svensson, David; Gillberg, Per-Göran; Hultin, Leif

    2008-01-01

    To simultaneously study gastric accommodation and peristaltic motility in the whole stomach of conscious rats by measuring intragastric pressure (IGP) during test-meal infusion. After an overnight fast, a test-meal infusion system and a catheter to measure IGP were connected to a chronically implanted gastric fistula. IGP was measured during infusion of an X-ray-opaque, non-nutritious viscous test meal (0.25-2 ml min(-1)); gastric motility and emptying were assessed by X-ray fluoroscopy. Peristaltic motility-induced IGP waves were quantified as a motility index (wave amplitude divided by wavelength). Experiments were performed in Sprague-Dawley (SD) rats and in the high-anxiety Wistar Kyoto (WKY) rats. Moreover, the effects of 30 mg kg(-1) NG-nitro-L-arginine methyl ester (L-NAME), 1 mg kg(-1) atropine or 20 mg kg(-1) molsidomine were tested in SD rats. Compared with SD rats, IGP increased significantly faster during stomach distension in WKY rats, indicating impaired accommodation in the latter strain. Motility indices did not differ between the two strains. L-NAME significantly increased IGP during stomach distension, indicating decreased gastric accommodation. However, no change in motility indices was observed with L-NAME. Treatment with atropine significantly increased IGP and decreased motility indices, indicating decreased gastric accommodation and motility. Molsidomine significantly decreased IGP during stomach distension but did not affect motility. The results correspond to X-ray observations, and confirm literature data. We conclude that IGP measurement during test-meal infusion represents an efficient and novel method to compare gastric accommodation and peristaltic motility in the whole stomach of conscious rats.

  4. [The Effect of Cortical Spreading Depression Wave on EEG Spectral Power Anaesthesed and Conscious Rats].

    Science.gov (United States)

    Koroleva, V I; Sakharov, D S; Bogdanov, A V

    2016-01-01

    EEG power changes in anaesthetized and conscious rats were studied (under repeated experiments) in wide frequency band (0.1-200 Hz) during cortical spreading depression wave (SD). In anaesthetized rats the decrease of EEG spectral power was shown through all diapasons under consideration. The most pronounced decay of the EEG power was marked in the 30-40 Hz band (27.3 ± 18.5, p = 2.46 x 10-(11)). In other frequency ranges the power decrease was less but its significance remained high. In conscious rats the simultaneous decay of the EEG power from 20 to 100 Hz range was also the most informative index of SD wave. The maximum power loss was found for band 30-40 Hz (11.2 ± 7.8, p = 2.55 x 10(-7)). It was shown that besides of EEG power decay the development of SD wave was characterized by the appearance of high frequency activity in front of SD and at the end of it. The increase of high-frequency activity in front of SD wave appeared in the ipsilateral hemisphere and moved along the cortex with the velocity of the SD wave itself. However the bursts of high frequency activity at the end of unilateral SD occurred simultaneously in both hemispheres and lasted 1.5-2.5 min. Findings contribute to detection of SD wave on basis of EEG spectral analysis.

  5. Effects of 4 multitargeted receptor tyrosine kinase inhibitors on regional hemodynamics in conscious, freely moving rats

    Science.gov (United States)

    Carter, Joanne J.; Fretwell, Laurice V.; Woolard, Jeanette

    2017-01-01

    VEGF inhibitors, including receptor tyrosine kinase inhibitors, are used as adjunct therapies in a number of cancer treatments. An emerging issue with these drugs is that most cause hypertension. To gain insight into the physiological mechanisms involved, we evaluated their regional hemodynamic effects in conscious rats. Male Sprague Dawley rats (350–450 g) were chronically implanted with pulsed Doppler flow probes (renal and mesenteric arteries, and the descending abdominal aorta) and catheters (jugular vein, peritoneal cavity, and distal abdominal aorta). Regional hemodynamics were measured over 4 d, before and after daily administration of cediranib (3 and 6 mg/kg, 3 and 6 mg/kg/h for 1 h, i.v.), sorafenib (10 and 20 mg/kg, 10 and 20 mg kg/h for 1 h, i.v.), pazopanib (30 and100 mg/kg, i.p.), or vandetanib (12.5 and 25 mg/kg, i.p.). All drugs evoked significant increases (P phentolamine and propranolol (each 1 mg/kg/h), suggesting a need for new strategies to overcome them.—Carter, J. J., Fretwell, L. V., Woolard, J. Effects of 4 multitargeted receptor tyrosine kinase inhibitors on regional hemodynamics in conscious, freely moving rats. PMID:27986807

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

    Science.gov (United States)

    Salman, Ibrahim M; Sarma Kandukuri, Divya; Harrison, Joanne L; Hildreth, Cara M; Phillips, Jacqueline K

    2015-01-01

    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 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.

  7. Urodynamic investigation of cyclophosphamide-induced overactive bladder in conscious rats

    Institute of Scientific and Technical Information of China (English)

    PAN Feng; LIU Di; HAN Xiao-min; LI Wen-cheng; PANG Zi-li; LI Bing; ZHANG Xiao-ping; XIAO Ya-jun; ZENG Fu-qing

    2012-01-01

    Background Overactive bladder (OAB) can be caused by many factors such as inflammation,bladder outlet obstruction,neurogenic factors.We performed an intraperitoneal (ip) injection of cyclophosphamide to induce cystitis in rats,which causes their detrusors to overact,to provide a valuable disease model for discussing OAB pathogenesis and to study effective curing methods.Methods Female Sprague-Dawley rats were induced to form cystitis by cyclophosphamide (200 mg/kg,ip).The day after the injection,two catheters were inserted into each rat's bladder to study its urodynamics.The BL-410 model bio-function experimental system was used to monitor bladder pressure while the rats were conscious.Unstable detrusor contractions appear in the urine storage period as a standard to determine OAB,and the positive rate was calculated.Urodynamic parameters such as bladder basal pressure (BP),maximum voiding pressure (MVP),intercontraction interval (ICI),spontaneous activity (SA),maximum cystometric capacity (MCC),and bladder compliance (BC) were recorded in each group,and a light microscope was used to observe the pathological changes in the rat bladder tissue.Results The detrusor instability rate of the model group was 83.33%.The MVP,MCC and BC of rats in the model group were lower than the control group (P <0.01),and the BP,ICI and SA of the model group rats were higher than the control group (P <0.01).The difference between the control group and the model group is statistically significant.The model group rats' bladder walls swelled and bled,the submucosa thickened and leukocyte infiltration became serious.Conclusions Acute cystitis and OAB symptoms can be induced by ip injections of cyclophosphamide in rats.This can provide a valuable animal model to study OAB in human beings.

  8. Progression of glomerular filtration rate reduction determined in conscious Dahl salt-sensitive hypertensive rats.

    Science.gov (United States)

    Cowley, Allen W; Ryan, Robert P; Kurth, Terry; Skelton, Meredith M; Schock-Kusch, Daniel; Gretz, Norbert

    2013-07-01

    Sequential changes in glomerular filtration rate during development of hypertension in the conscious Dahl salt-sensitive rats were determined using a new method for measurement. Using a miniaturized device, disappearance curves of fluorescein isothiocyanate-sinistrin were measured by transcutaneous excitation and real-time detection of the emitted light through the skin. Rats with implanted femoral venous catheters (dye injection and sampling) and carotid catheters (mean arterial pressure by telemetry) were studied, while maintained on a 0.4% NaCl diet and on days 2, 5, 7, 14, and 21 after switching to 4.0% (high-salt [HS]) diet. A separate group of rats were maintained on 0.4% for 21 days as a time control. Mean arterial pressure rose progressively from the last day of 0.4% (130±2 mm Hg) reaching significance by day 5 of HS and averaged 162±7 mm Hg by day 21. Urine albumin excretion was significantly elevated (×3) by day 7 of HS in Dahl salt-sensitive rats. Glomerular filtration rate reduced on day 14 of HS falling from 1.53±0.06 mL/min per 100 g body weight to 1.27±0.04. By day 21, glomerular filtration rate had fallen 28% to 1.1±0.04 mL/min per 100 g (t(1/2) 28.4±1.1 minute.) No significant reductions of creatinine clearance were observed throughout the study in response to HS demonstrating the insensitivity of creatinine clearance measurements even with creatinine measured using mass spectrometry. We conclude that the observed reduction of glomerular filtration rate was a consequence and not a cause of the hypertension and that this noninvasive approach could be used in these conscious Dahl salt-sensitive rats for a longitudinal assessment of renal function.

  9. The effect of adrenal demedullation on cardiovascular responses to environmental stimulation in conscious rats.

    Science.gov (United States)

    Borkowski, K. R.; Kelly, E.

    1986-01-01

    Circulating plasma adrenaline has been implicated in the facilitation of neurogenic pressor responses and development of hypertension. Bilateral adrenal demedullation in rats did not affect body weight, urine output, urinary electrolyte (Na+, K+ and Cl-) excretion, nor plasma corticosterone concentration, indicating the selective nature of the demedullation procedure. Adrenal demedullation did induce significant reductions in adrenal catecholamine content, plasma adrenaline levels, resting blood pressure and heart rate in conscious rats, but did not affect alerting-induced increases in blood pressure. The adrenal medulla and circulating plasma adrenaline appear to contribute to the maintenance of resting cardiovascular parameters, but would not appear to be involved in nor facilitate the cardiovascular responses to environmental stimulation. PMID:3742165

  10. Mechanisms contributing to the regional haemodynamic effects of neurotensin in conscious, unrestrained Long Evans rats.

    Science.gov (United States)

    Bachelard, H; Gardiner, S M; Kemp, P A; Bennett, T

    1992-01-01

    1. The regional haemodynamic effects of i.v. bolus doses of neurotensin (10-1000 ng) were assessed in conscious, unrestrained Long Evans rats chronically instrumented with miniaturized, pulsed Doppler probes. 2. Neurotensin caused increases in blood pressure, together with dose-related tachycardias and constrictions in the renal, superior mesenteric and hindquarters vascular beds. The tachycardia elicited by the 1000 ng dose of neurotensin was preceded by a transient bradycardia. 3. In the presence of phentolamine, the pressor effect of neurotensin (1000 ng) was converted into a hypotensive effect, accompanied by reduced tachycardic and constrictor responses in the renal, superior mesenteric and hindquarters vascular beds. The tachycardia was not preceded by a bradycardia. 4. In the presence of phentolamine and propranolol, the pressor and bradycardic responses to neurotensin were unaffected, whereas the tachycardia was abolished. The renal vasconstrictor effect was smaller, while the constrictions in the superior mesenteric and hindquarters vascular beds were not different from those in untreated rats. 5. In rats neonatally treated with capsaicin (50 mg kg-1, s.c.), the pressor effects elicited by neurotensin (300 and 1000 ng) were reduced as were the constrictor responses in the renal (at the dose of 300 ng), superior mesenteric (at the dose of 300 ng) and hindquarters (at both doses) vascular beds. The bradycardia elicited by neurotensin (1000 ng) was absent, whereas the tachycardia was potentiated. 6. The results indicate that in conscious, intact rats neurotensin appears to exert cardiovascular influences through activation of sympathoadrenal mechanisms and also through non-adrenergic effects on the heart, renal, superior mesenteric and hindquarters vascular beds. The latter effects appear to involve capsaicin-sensitive nerves.

  11. Impacts of peripheral obestatin on colonic motility and secretion in conscious fed rats.

    Science.gov (United States)

    Chen, C Y; Chien, E J; Chang, F Y; Lu, C L; Luo, J C; Lee, S D

    2008-09-01

    Obestatin, a novel putative 23-amino acid peptide, was found to be derived from a mammalian preproghrelin gene by using a bioinformatics approach. Although the effects of obestatin on food intake and upper gut motility remain controversial, no studies have been carried out to explore its influence on lower gut motility and secretion. We investigated the impacts of intravenous (IV) injection of obestatin on rat colonic motor and secretory functions. Colonic transit time, fecal pellet output, and fecal content were measured in freely fed, conscious rats, which were chronically implanted with IV and colonic catheters. To test the validity of this animal model, human/rat corticotropin-releasing factor (h/rCRF) served as a stimulatory inducer of colonic motility and secretion. IV injection of obestatin (45, 100, and 300 nmol/kg) did not affect the colonic transit time, whereas IV injection of h/rCRF (30 nmol/kg) effectively accelerated colonic transit time. IV obestatin, in every dose we tested, also did not modify fecal pellet output, frequency of watery diarrhea, total fecal weight, fecal dried solid weight, or fecal fluid weight in the first hour after injection. On the other hand, IV injection of h/rCRF significantly enhanced fecal pellet output, as well as increased the frequency of watery diarrhea, total fecal weight, fecal dried solid weight, and fecal fluid weight during the first hour after injection compared with IV saline controls. In conclusion, peripheral obestatin administration has no impact on colonic motility and secretion in conscious fed rats.

  12. Amino Acids That Centrally Influence Blood Pressure and Regional Blood Flow in Conscious Rats

    Directory of Open Access Journals (Sweden)

    Yumi Takemoto

    2012-01-01

    Full Text Available Functional roles of amino acids have increasingly become the focus of research. This paper summarizes amino acids that influence cardiovascular system via the brain of conscious rats. This paper firstly describes why amino acids are selected and outlines how the brain regulates blood pressure and regional blood flow. This section includes a concise history of amino acid neurotransmitters in cardiovascular research and summarizes brain areas where chemical stimulations produce blood pressure changes mainly in anesthetized animals. This is followed by comments about findings regarding several newly examined amino acids with intracisternal stimulation in conscious rats that produce changes in blood pressure. The same pressor or depressor response to central amino acid stimulations can be produced by distinct mechanisms at central and peripheral levels, which will be briefly explained. Thereafter, cardiovascular actions of some of amino acids at the mechanism level will be discussed based upon findings of pharmacological and regional blood flow measurements. Several examined amino acids in addition to the established neurotransmitter amino acids appear to differentially activate brain structures to produce changes in blood pressure and regional blood flows. They may have physiological roles in the healthy brain, but pathological roles in the brain with cerebral vascular diseases such as stroke where the blood-brain barrier is broken.

  13. Structured triglyceride vehicles for oral delivery of halofantrine: examination of intestinal lymphatic transport and bioavailability in conscious rats

    DEFF Research Database (Denmark)

    Holm, René; Porter, Christopher J H; Müllertz, Anette

    2002-01-01

    animals, and this was most pronounced for the animals dosed with the structured triglycerides. CONCLUSIONS: Using MLM as vehicle increases the portal absorption of halofantrine and results in similar lymphatic transport levels when compared to sunflower oil. Total absorption when assessed as absorption...... in the blood plus lymphatic transport for halofantrine after administration in the MLM triglyceride was higher than after administration in sunflower oil.......PURPOSE: To compare the influence of triglyceride vehicle intramolecular structure on the intestinal lymphatic transport and systemic absorption of halofantrine in conscious rats. METHODS: Conscious, lymph cannulated and nonlymph cannulated rats were dosed orally with three structurally different...

  14. Characteristic enhancement of blood pressure V-shaped waves in sinoaortic-denervated rats in a conscious and quiet state.

    Science.gov (United States)

    Chang, Huan; Gu, Hong-Xia; Gong, Min; Han, Ji-Ju; Wang, Yun; Xia, Zuo-Li; Zhao, Xiao-Min

    2016-11-08

    A hemodynamic feature of chronic sinoaortic-denervated (SAD) rats is the increase in blood pressure variability (BPV) without significant changes in the average level of blood pressure (BP). The current study was designed to investigate the changes in BP V-shaped waves (V waves) in SAD rats. Sprague-Dawley (SD) rats were divided into 2 groups: SAD rats and sham-operated rats (n=13). Hemodynamics measurements were obtained in conscious, freely moving rats, four weeks after sinoaortic denervation or sham operation. V wave indices were evaluated in rats in both conscious and quiet states. Additionally, normal and high BPV was simulated by the production of V waves with different amplitudes. The results showed that the V wave amplitude was dramatically increased, with a significantly prolonged duration and reduced frequency in SAD rats. V wave BPV in SAD rats was significantly increased, though BP remained unchanged. The twenty-four hour BPV in all rats was positively correlated with amplitude, duration time and V wave BPV and negatively correlated with frequency. The systolic BP spectral powers in the low frequency range (0.38-0.45 Hz) were significantly reduced in the V waves of SAD rats. Moreover, there was a remarkable increase in mean BPV and a normal mean BP after simulating high BPV in SAD rats. These results suggest that enhancement of V waves might be a waveform character of BP in SAD rats in both the conscious and quiet states. These types of V waves appear to be related to a depression of sympathetic regulation of BP induced by sinoaortic denervation.

  15. Initial studies using the RatCAP conscious animal PET tomograph

    Energy Technology Data Exchange (ETDEWEB)

    Woody, C. [Brookhaven National Laboratory, Upton, NY (United States)]. E-mail: woody@bnl.gov; Vaska, P. [Brookhaven National Laboratory, Upton, NY (United States); Schlyer, D. [Brookhaven National Laboratory, Upton, NY (United States); Pratte, J.-F. [Brookhaven National Laboratory, Upton, NY (United States); Junnarkar, S. [Brookhaven National Laboratory, Upton, NY (United States); Park, S.-J. [Brookhaven National Laboratory, Upton, NY (United States); Stoll, S. [Brookhaven National Laboratory, Upton, NY (United States); Purschke, M. [Brookhaven National Laboratory, Upton, NY (United States); Southekal, S. [Stony Brook University, Stony Brook, NY (United States); Kriplani, A. [Stony Brook University, Stony Brook, NY (United States); Krishnamoorthy, S. [Stony Brook University, Stony Brook, NY (United States); Maramraju, S. [Stony Brook University, Stony Brook, NY (United States); Lee, D. [Brookhaven National Laboratory, Upton, NY (United States); Schiffer, W. [Brookhaven National Laboratory, Upton, NY (United States); Dewey, S. [Brookhaven National Laboratory, Upton, NY (United States); Neill, J. [Long Island University, Brookville, NY (United States); Kandasamy, A. [Brookhaven National Laboratory, Upton, NY (United States); O' Connor, P. [Brookhaven National Laboratory, Upton, NY (United States); Radeka, V. [Brookhaven National Laboratory, Upton, NY (United States); Fontaine, R. [Sherbrooke University, Sherbrooke, Que. (Canada); Lecomte, R. [Sherbrooke University, Sherbrooke, Que. (Canada)

    2007-02-01

    The RatCAP is a small, head-mounted PET tomograph designed to image the brain of a conscious rat without the use of anesthesia. The detector is a complete, high-performance 3D tomograph consisting of a 3.8 cm inside-diameter ring containing 12 block detectors, each of which is comprised of a 4x8 array of 2.2x2.2x5 mm{sup 3} LSO crystals readout with a matching APD array and custom ASIC, and has a 1.8 cm axial field of view. Construction of the first working prototype detector has been completed and its performance characteristics have been measured. The results show an intrinsic spatial resolution of 2.1 mm, a time resolution of {approx}14 ns FWHM, and a sensitivity of 0.7% at an energy threshold of 150 keV. First preliminary images have been obtained using {sup 18}F-FDG and {sup 11}C-methamphetamine, which show comparable image quality to those obtained from a commercial MicroPET R4 scanner. Initial studies have also been carried out to study stress levels in rats wearing the RatCAP.

  16. Serum immunoreactive erythropoietin and red blood cell mass during pregnancy in conscious rats.

    Science.gov (United States)

    Del Valle, G O; Mosher, M D; Conrad, K P

    1993-08-01

    Serum erythropoietin concentration increases during human pregnancy and presumably accounts for expansion of red blood cell mass. The mechanism(s) underlying gestational changes of serum erythropoietin are unknown. Moreover, if erythropoietin synthesis increases, then the organ(s) questions about erythropoietin in pregnancy, we first set out to establish an animal model. Chronically instrumented, conscious unrestrained rats were studied. 51Cr-labeled red blood cells and radioimmunoassay were used to assess red blood cell mass and serum erythropoietin, respectively. Except for a lower hematocrit (P pregnancy rats were comparable to those measured in virgin control animals. Significant increases in total blood volume, plasma volume, and red blood cell mass were observed by gestational day 13 (midpregnancy) when compared with virgin control rats. These changes were even more pronounced on gestational day 20. Serum immunoreactive erythropoietin was also significantly increased at both of these stages of pregnancy. We conclude that the gravid rat is a reliable animal model of human gestation in which to further investigate erythropoietin in pregnancy.

  17. Studies on the adrenomedullary dependence of kappa-opioid agonist-induced diuresis in conscious rats.

    Science.gov (United States)

    Borkowski, K. R.

    1989-01-01

    1. The dependence of kappa-opioid agonist-induced diuresis, upon an intact and functional adrenal medulla in conscious rats, was investigated in order to test the hypothesis that the diuresis is mediated by a blood-borne 'diuretic factor', of adrenomedullary origin, released by kappa-opioid receptor stimulation. 2. Confirming previous observations, adrenal demedullation significantly attenuated diuretic responses to the kappa-opioid agonists U50488H, ethylketocyclazocine (EKC) and tifluadom, but did not affect basal urine output, furosemide-induced diuresis or the antidiuretic response to the mu-opioid agonist, buprenorphine. Naloxone abolished U50488H-induced diuresis, confirming an involvement of opioid receptors. 3. Transfusion studies established that blood, from intact rats treated with U50488H, induced diuresis in intact and demedullated recipient rats, whether or not the recipients had been pretreated with naloxone. However, blood from demedullated rats treated with U50448H was unable to induce diuresis when administered to intact or demedullated recipients. 4. It is concluded that kappa-opioid agonist-induced diuresis is dependent upon an intact and functional adrenal medulla and appears to be mediated by a blood-borne 'diuretic factor' of adrenomedullary origin. PMID:2558758

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

    Directory of Open Access Journals (Sweden)

    Ibrahim M Salman

    2015-08-01

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

  19. The effects of a new opioid analgesic, meptazinol, on the respiration of the conscious rat.

    Science.gov (United States)

    Cowlrick, I S; Shepperson, N B

    1985-05-01

    In the conscious rat arterial PCO2 was measured as an index of respiratory status. The opioid analgesic meptazinol (7.5 - 30 mg kg-1) evoked small but significant increases in arterial PCO2 which were attenuated by naloxone. Meptazinol significantly reduced the increase in arterial PCO2 evoked by morphine. The respiratory depression induced by meptazinol, but not that induced by morphine, was enhanced by pretreatment with atropine. The (+)-enantiomer, but not the (-)-enantiomer of meptazinol increased arterial PCO2. In contrast, only the (-)-enantiomer reduced the respiratory depressant effect of morphine. It is proposed that the degree of respiratory depression induced by meptazinol is limited by its opioid antagonist and cholinomimetic properties.

  20. Responses to noradrenaline of tail arteries in hypertensive, hypotensive and normotensive rats under different regimens of perfusion: role of the myogenic response

    DEFF Research Database (Denmark)

    Matchkov, Vladimir; Vlasova, Maria A; Tarasova, Olga S;

    1998-01-01

    The vasoconstrictor effects of noradrenaline were studied in spontaneously hypertensive rats (SHR) compared with Wistar Kyoto rats (WKY), and in Wistar rats with regional hypotension (WH) compared to control Wistar rats (WC). The abdominal aorta was ligated in WH distal to the renal arteries...... thickness causing different degrees of activation of the myogenic response to distension....

  1. Increased hepatic nicotine elimination after phenobarbital induction in the conscious rat

    Energy Technology Data Exchange (ETDEWEB)

    Foth, H.; Walther, U.I.; Kahl, G.F. (Univ. of Goettingen (Germany, F.R.))

    1990-09-15

    Elimination parameters of (14C)nicotine in conscious rats receiving nicotine (0.3 mg/kg) either intravenously or orally were studied. The oral availability of unchanged nicotine, derived by comparison of the respective areas under the concentration vs time curves (AUC), was 89%, indicating low hepatic extraction ratios of about 10%. Pretreatment of rats with phenobarbital (PB) markedly increased hepatic first-pass extraction of nicotine. The oral availability of unchanged nicotine in plasma dropped to 1.4% of the corresponding values obtained from PB-treated rats receiving nicotine iv. After PB pretreatment, the clearance of iv nicotine was increased approximately twofold over controls, much less than the observed more than ninefold increase of hepatic first-pass extraction. It is assumed that extrahepatic metabolism contributed significantly to the rapid removal of nicotine from the plasma. The elimination of cotinine, originating from nicotine administered either po or iv, was significantly increased by PB pretreatment, as determined by the ratio of corresponding AUCs. The pattern of nicotine metabolites in urine also indicated an increase in the rate of cotinine metabolic turnover. The amount of norcotinine in the organic extract of urine paralleled PB microsomal enzyme induction. The ratio between urinary concentrations of the normetabolite and cotinine correlated strongly with the PB-induced state of rat liver. This may be a suitable indicator of PB-inducible hepatic cytochrome P450 isoenzyme(s). Since smoking habits in man are feedback-regulated by nicotine plasma concentrations, a similar increase of nicotine elimination by microsomal enzyme induction in man may be of relevance for tobacco consumption.

  2. Water drinking-related muscle contraction induces the pressor response via mechanoreceptors in conscious rats.

    Science.gov (United States)

    Abe, Chikara; Iwata, Chihiro; Morita, Hironobu

    2013-01-01

    Water drinking is known to induce the pressor response. The efferent pathway in this response involves sympathoexcitation, because the pressor response was completely abolished by ganglionic blockade or an α(1)-adrenergic antagonist. However, the afferent pathway in this response has not been identified. In the present study, we hypothesized that water itself stimulates the upper digestive tract to induce the pressor response, and/or drinking-related muscle contraction induces the pressor response via mechanoreceptors. To examine this hypothesis, we evaluated the pressor response induced by spontaneous or passive water drinking in conscious rats. Since the baroreflex modulates and obscures the pressor response, the experiments were conducted using rats with sinoaortic denervation. The pressor response was not suppressed by 1) transient oral surface anesthesia using lidocaine, 2) bilateral denervation of the glossopharyngeal nerve and sensory branch of the superior laryngeal nerve, or 3) denervation of the tunica adventitia in the esophagus. However, the pressor response was significantly suppressed (by -52%) by intravenous gadolinium chloride administration. Electrical stimulation of the hypoglossal nerve induced the pressor response, which was significantly suppressed (by -57%) by intravenous gadolinium chloride administration and completely abolished by severing the distal end of this nerve. These results indicate that afferent signals from mechanoreceptors in drinking-related muscles are involved in the water drinking-induced pressor response.

  3. Consequences of brief exposure to high concentrations of carbon monoxide in conscious rats.

    Science.gov (United States)

    Gu, Zengfa; Januszkiewicz, Adolph J; Mayorga, Maria A; Coleman, Gary D; Morrissette, Craig R

    2005-12-01

    Exposure to high-concentration carbon monoxide (CO) is of concern in military operations. Experimentally, the physiologic manifestations of a brief exposure to elevated levels of CO have not been fully described. This study investigated the development of acute CO poisoning in conscious male Sprague-Dawley rats (220-380 g). Animals were randomly grouped (n = 6) and exposed to either air or 1 of 6 CO concentrations (1000, 3000, 6000, 10,000, 12,000, or 24,000 ppm) in a continuous air/CO dynamic exposure chamber for 5 min. Respiration was recorded prior to and during exposures. Mixed blood carboxyhemoglobin (COHb) and pH were measured before and immediately after exposure. Before exposure the mean baselines of respiratory minute volumes (RMVs) were 312.6 +/- 43.9, 275.2 +/- 40.8, and 302.3 +/- 39.1 ml/min for the 10,000, 12,000 and 24,000 ppm groups, respectively. In the last minute of exposure RMVs were 118.9 +/- 23.7, 62.1 +/- 10.4, and 22.0 +/- 15.1% (p 82%. Blood pH was unaltered and no death occurred in rats exposed to CO at concentrations 10,000 ppm for brief periods as short as 5 min may change RMV, resulting in acute respiratory failure, acidemia, and even death.

  4. Effects and mechanisms of auricular electroacupuncture on visceral pain induced by colorectal distension in conscious rats.

    Science.gov (United States)

    Li, Han; Hu, Shasha; Zhang, Jianbin; Zhou, Jingzhu; Ran, Hongxing; Tang, Yichun; Chen, Jiande; Wang, Yinping

    2014-12-01

    To investigate the effects and mechanisms of action of auricular electroacupuncture (AEA) on visceral pain induced by colorectal distension (CRD). Twenty-nine female Sprague-Dawley rats were randomly divided into four groups: control; untreated CRD; CRD+AEA; and CRD+sham electroacupuncture (SEA). An electromyogram (EMG) was recorded for 120 min in the conscious state. After a 30 min baseline recording, CRD was performed in untreated CRD, AEA and SEA groups and lasted for 90 min. AEA and SEA were started at 30 min and lasted for 30 min. The EMG was recorded and analysed to evaluate the severity of visceral pain, indicated by the magnitude of the vasomotor response (VMR). mRNA expression of the 5-hydroxytryptamine 1a (5-HT1a) receptor was measured separately in the colon and raphe nuclei using real-time fluorescent quantitative PCR. No differences were seen in the baseline EMG among the four groups (p>0.05). During pre-stimulation, VMR magnitude in the CRD, AEA and SEA groups increased compared with that in the control group (pvisceral pain in rats, and increase mRNA expression of the 5-HT1a receptor peripherally (in the colon) and centrally (in the raphe nuclei), suggesting a serotonergic mechanism of action. 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. Noninvasive method for electrocardiogram recording in conscious rats: feasibility for heart rate variability analysis

    Directory of Open Access Journals (Sweden)

    Pedro P. Pereira-Junior

    2010-06-01

    Full Text Available Heart rate variability (HRV analysis consists in a well-established tool for the assessment of cardiac autonomic control, both in humans and in animal models. Conventional methods for HRV analysis in rats rely on conscious state electrocardiogram (ECG recording based on prior invasive surgical procedures for electrodes/transmitters implants. The aim of the present study was to test a noninvasive and inexpensive method for ECG recording in conscious rats, assessing its feasibility for HRV analysis. A custom-made elastic cotton jacket was developed to fit the rat's mean thoracic circumference, with two pieces of platinum electrodes attached on its inner surface, allowing ECG to be recorded noninvasively in conscious, restrained rats (n=6. Time- and frequency-domain HRV analyses were conducted, under basal and autonomic blockade conditions. High-quality ECG signals were obtained, being feasible for HRV analysis. As expected, mean RR interval was significantly decreased in the presence of atropine (p A análise da variabilidade da freqüência cardíaca (VFC consiste em uma metodologia bem estabelecida para o estudo do controle autonômico cardíaco, tanto em humanos como em modelos animais. As metodologias convencionais para o estudo da VFC em ratos utilizam-se de procedimentos cirúrgicos para o implante de eletródios ou transmissores, o que possibilita a posterior aquisição do eletrocardiograma (ECG no estado consciente. O objetivo do presente trabalho foi o de desenvolver e aplicar um método não-invasivo para o registro do ECG em ratos conscientes, verificando sua validade para a análise da VFC. Uma vestimenta de tecido elástico em algodão foi desenvolvida de acordo com as dimensões médias da circunferência torácica dos animais, e dois pequenos eletródios retangulares de platina foram aderidos à superfície interna da vestimenta, permitindo o registro do ECG de forma não-invasiva em ratos conscientes (n=6, sob contenção. Foram

  6. Graded defragmentation of cortical neuronal firing during recovery of consciousness in rats.

    Science.gov (United States)

    Vizuete, J A; Pillay, S; Ropella, K M; Hudetz, A G

    2014-09-05

    State-dependent neuronal firing patterns reflect changes in ongoing information processing and cortical function. A disruption of neuronal coordination has been suggested as the neural correlate of anesthesia. Here, we studied the temporal correlation patterns of ongoing spike activity, during a stepwise reduction of the volatile anesthetic desflurane, in the cerebral cortex of freely moving rats. We hypothesized that the recovery of consciousness from general anesthesia is accompanied by specific changes in the spatiotemporal pattern and correlation of neuronal activity. Sixty-four contact microelectrode arrays were chronically implanted in the primary visual cortex (contacts spanning 1.4-mm depth and 1.4-mm width) for recording of extracellular unit activity at four steady-state levels of anesthesia (8-2% desflurane) and wakefulness. Recovery of consciousness was defined as the regaining of the righting reflex (near 4%). High-intensity firing (HI) periods were segmented using a threshold (200-ms) representing the minimum in the neurons' bimodal interspike interval histogram under anesthesia. We found that the HI periods were highly fragmented in deep anesthesia and gradually transformed to a near-continuous firing pattern at wakefulness. As the anesthetic was withdrawn, HI periods became longer and increasingly correlated among the units both locally and across remote recording sites. Paradoxically, in 4 of 8 animals, HI correlation was also high at the deepest level of anesthesia (8%) when local field potentials (LFP) were burst-suppressed. We conclude that recovery from desflurane anesthesia is accompanied by a graded defragmentation of neuronal activity in the cerebral cortex. Hypersynchrony during deep anesthesia is an exception that occurs only with LFP burst suppression. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Effect of pancreatic polypeptide on gastric accommodation and gastric emptying in conscious rats.

    Science.gov (United States)

    Verschueren, Sofie; Janssen, Pieter; Van Oudenhove, Lukas; Hultin, Leif; Tack, Jan

    2014-07-01

    Pancreatic polypeptide (PP) is an anorexigenic hormone released from pancreatic F cells upon food intake. We aimed to determine the effect of PP on gastric accommodation and gastric emptying in conscious Wistar HAN rats to investigate whether effects on motor function could contribute to its anorexigenic effects. Intragastric pressure (IGP) was measured through a chronically implanted gastric fistula during the infusion of a nutrient meal (Nutridrink; 0.5 ml/min). Rats were treated with PP (0, 33 and 100 pmol·kg(-1)·min(-1)) in combination with N(G)-nitro-L-arginine methyl ester (L-NAME; 180 mg·kg(-1)·h(-1)), atropine (3 mg·kg(-1)·h(-1)), or vehicle. Furthermore, the effect of PP was tested after subdiaphragmal vagotomy of the stomach. Gastric emptying of a noncaloric and a caloric meal after treatment with 100 pmol·kg(-1)·min(-1) PP or vehicle was compared using X-rays. PP significantly increased IGP during nutrient infusion compared with vehicle (P IGP during nutrient infusion compared with vehicle treatment (P IGP during nutrient infusion was abolished in the presence of L-NAME and in the presence of atropine. In vagotomized rats, PP increased IGP compared with intact controls (P < 0.05). PP significantly delayed gastric emptying of both a noncaloric (P < 0.05) and a caloric (P < 0.005) meal. PP inhibits gastric accommodation and delays gastric emptying, probably through inhibition of nitric oxide release. These results indicate that, besides the well-known centrally mediated effects, PP might decrease food intake through peripheral mechanisms. Copyright © 2014 the American Physiological Society.

  8. Different effects of ghrelin, des-acyl ghrelin and obestatin on gastroduodenal motility in conscious rats

    Institute of Scientific and Technical Information of China (English)

    Mineko Fujimiya; Aldhiro Asakawa; Koji Ataka; Ikuo Kato; Akio Inui

    2008-01-01

    Three peptides, ghrelin, des-acyl ghrelin and obestatin are derived from a common prohormone, preproghre-lin by posttranslational processing, originating from endocrine cells in the stomach. To examine the effects of these peptides, we applied the manometric mea-surement of gastrointestinal motility in freely moving conscious rat models. Ghrelin exerts stimulatory ef-fects on the motility of antrum and duodenum in both fed and fasted state of animals. Des-acyl ghrelin exerts inhibitory effects on the motility of antrum, but not on the motility of duodenum in the fasted state of ani-mals. Obestatin exerts inhibitory effects on the motility of antrum and duodenum in the fed state, but not in the fasted state of animals. NPY Y2 or Y4 receptors in the brain may mediate the action of ghrelin, CRF type 2 receptors in the brain mediate the action of des-acyl ghrelin, whereas CRF type 1 and type 2 receptors in the brain mediate the action of obestatin. Vagal affer-ent pathways might be involved in the action of ghre-lin, but not involved in the action of des-acyl ghrelin, whereas vagal afferent pathways might be partially involved in the action of obestatin.

  9. Induction and imaging of photothrombotic stroke in conscious and freely moving rats

    Science.gov (United States)

    Lu, Hongyang; Li, Yao; Yuan, Lu; Li, Hangdao; Lu, Xiaodan; Tong, Shanbao

    2014-09-01

    In experimental stroke research, anesthesia is common and serves as a major reason for translational failure. Real-time cerebral blood flow (CBF) monitoring during stroke onset can provide important information for the prediction of brain injury; however, this is difficult to achieve in clinical practice due to various technical problems. We created a photothrombotic focal ischemic stroke model utilizing our self-developed miniature headstage in conscious and freely moving rats. In this model, a high spatiotemporal resolution imager using laser speckle contrast imaging technology was integrated to acquire real-time two-dimensional CBF information during thrombosis. The feasibility, stability, and reliability of the system were tested in terms of CBF, behavior, and T2-weighted magnetic resonance imaging (MRI) findings. After completion of occlusion, the CBF in the targeted cortex of the stroke group was reduced to 16±9% of the baseline value. The mean infarct volume measured by MRI 24 h postmodeling was 77±11 mm3 and correlated well with CBF (R2=0.74). This rodent model of focal cerebral ischemia and real-time blood flow imaging opens the possibility of performing various fundamental and translational studies on stroke without the influence of anesthetics.

  10. Qualification of fMRI as a biomarker for pain in anesthetized rats by comparison with behavioral response in conscious rats.

    Science.gov (United States)

    Zhao, Fuqiang; Williams, Mangay; Bowlby, Mark; Houghton, Andrea; Hargreaves, Richard; Evelhoch, Jeffrey; Williams, Donald S

    2014-01-01

    fMRI can objectively measure pain-related neural activities in humans and animals, providing a valuable tool for studying the mechanisms of nociception and for developing new analgesics. However, due to its extreme sensitivity to subject motion, pain fMRI studies are performed in animals that are immobilized, typically with anesthesia. Since anesthesia could confound the nociceptive processes, it is unknown how well nociceptive-related neural activities measured by fMRI in anesthetized animals correlate with nociceptive behaviors in conscious animals. The threshold to vocalization (VT) in response to an increasing noxious electrical stimulus (NES) was implemented in conscious rats as a behavioral measure of nociception. The antinociceptive effect of systemic (intravenous infusion) lidocaine on NES-induced fMRI signals in anesthetized rats was compared with the corresponding VT in conscious rats. Lidocaine infusion increased VT and suppressed the NES-induced fMRI signals in most activated brain regions. The temporal characteristics of the nociception signal by fMRI and by VT in response to lidocaine infusion were highly correlated with each other, and with the pharmacokinetics (PK) of lidocaine. These results indicate that the fMRI activations in these regions may be used as biomarkers of acute nociception in anesthetized rats. Interestingly, systemic lidocaine had no effect on NES-induced fMRI activations in the primary somatosensory cortex (S1), a result that warrants further investigation.

  11. Regional haemodynamic effects of noradrenaline injected into the hypothalamic paraventricular nuclei of conscious, unrestrained rats: possible mechanisms of action.

    Science.gov (United States)

    Bachelard, H; Harland, D; Gardiner, S M; Kemp, P A; Bennett, T

    1992-01-01

    The cardiovascular effects of noradrenaline bilaterally injected into the hypothalamic paraventricular nuclei were investigated in conscious, unrestrained Long-Evans rats and homozygous, vasopressin-deficient Brattleboro rats, chronically instrumented with pulsed Doppler probes for measurement of regional haemodynamics. In Long-Evans rats, incremental doses of noradrenaline (0.01-10 nmol) caused dose-related increases in blood pressure and a substantial, dose-related, superior mesenteric vasoconstriction. These changes were accompanied by bradycardia and reductions in renal and hind-quarter vascular conductances. In Brattleboro rats, noradrenaline (10 nmol) had no effect on blood pressure, heart rate, or renal or superior mesenteric vascular conductances. However, there was a slight vasodilatation in the vascular bed of the hindquarters. In Long-Evans rats, intravenous pretreatment with phentolamine had no effect on the bradycardia but partly inhibited the pressor response to noradrenaline injected into the paraventricular nuclei. These effects were associated with a smaller superior mesenteric vasoconstriction and an abolition of the vasoconstriction in the hindquarters. Combined intravenous pretreatment with phentolamine and propranolol had no effect on the heart rate or pressor responses to noradrenaline injected into the paraventricular nuclei, but reduced the superior mesenteric vasoconstriction, potentiated the vasoconstriction in the hindquarters and eliminated the renal vasoconstriction. These results suggest that, in untreated Long-Evans rats, alpha-adrenoceptor-mediated constriction in the mesenteric vascular bed and beta-adrenoceptor-mediated dilatation in the vascular bed of the hindquarters have important influences on the pressor response to noradrenaline injected into the paraventricular nuclei. In the presence of the vasopressin V1-receptor antagonist, d(CH2)5[Tyr(Et)]DAVP, the pressor and heart rate responses to noradrenaline injected into the

  12. Antinociceptive action against colonic distension by brain orexin in conscious rats.

    Science.gov (United States)

    Okumura, Toshikatsu; Nozu, Tsukasa; Kumei, Shima; Takakusaki, Kaoru; Miyagishi, Saori; Ohhira, Masumi

    2015-02-19

    Increasing evidence has suggested that brain orexins are implicated in a wide variety of physiological functions. With regard to gastrointestinal functions, orexin-A acts centrally to regulate gastrointestinal functions such as gastric and pancreatic secretion, and gastrointestinal motility. Visceral sensation is also known as one of key gastrointestinal functions which are controlled by the central nervous system. Little is, however, known about a role of central orexin in visceral sensation. This study was therefore performed to clarify whether brain orexin may be involved in the process of visceral sensation. Visceral sensation was evaluated by colonic distension-induced abdominal withdrawal reflex (AWR) in conscious rats. Intracisternally administered orexin-A dose-dependently increased the threshold volume of colonic distension-induced AWR. In contrast, neither intraperitoneal injection of orexin-A nor intracisternal orexin-B altered the threshold volume. While intracisternal SB334867, an orexin 1 receptor antagonist, by itself failed to change the threshold volume, SB334867 injected centrally completely blocked the morphine-induced antinociceptive action against colonic distension. These results suggest for the first time that orexin-A specifically acts centrally in the brain to enhance antinociceptive response to colonic distension. We would furthermore suggest that endogenous orexin-A indeed mediates the antinociceptive effect of morphine on visceral sensation through the orexin 1 receptors. All these evidence might indicate that brain orexin plays a role in the pathophysiology of functional gastrointestinal disorders such as irritable bowel syndrome because visceral hypersensitivity of the gut is considered to play a vital role in the diseases.

  13. Long-term modifications of blood pressure in normotensive and spontaneously hypertensive rats by gene delivery of rAAV-mediated cytochrome P450 arachidonic acid hydroxylase

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Arachidonic acid cytochrome P-450 (CYP) hydroxylase 4A isoforms, including 4A1, 4A2, 4A3 and 4A8 in the rat kidney, catalyze arachidonic acid to produce 19/20-Hydroxyeicosatetraenoic acids (20-HETE), a biologically active metabolite, which plays an important role in the regulation of blood pressure. However, controversial results have been reported regarding the exact role of 20-HETE on blood pressure. In the present study, we used recombinant adenoassociated viral vector (rAAV) to deliver CYP 4A1 cDNA and antisense 4A1 cDNA into Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR), respectively, to investigate the effects of long-term modifications of blood pressure and the potential for gene therapy of hypertension. The mean systolic pressure increased by 14.2±2.5 mm Hg in rAAV.4A1-treated SD rats and decreased by 13.7±2.2 mm Hg in rAAV.anti4A1-treated SHR rats 5 weeks after the injection compared with controls and these changes in blood pressure were maintained until the experiments ended at 24weeks. In 4A1 treated animals CYP4A was overexpressed in various tissues, but preferentially in the kidney at both mRNA and protein levels. In anti-4A1-treated SHR, CYP4A mRNA in various tissues was probed, especially in kidneys,but 4A1 protein expression was almost completely inhibited. These results suggest that arachidonic acid CYP hydroxylases contribute not only to the maintenance of normal blood pressure but also to the development of hypertension.rAAV-mediated anti4A administration strategy has the potential to be used as targeted gene therapy in human hypertension by blocking expression of CYP 4A in kidneys.

  14. A novel simultaneous measurement method to assess the influence of intracerebroventricular obestatin on colonic motility and secretion in conscious rats.

    Science.gov (United States)

    Chen, Chih-Yen; Doong, Ming-Luen; Li, Chung-Pin; Liaw, Wen-Jinn; Lee, Hsing-Feng; Chang, Full-Young; Lin, Han-Chieh; Lee, Shou-Dong

    2010-06-01

    Obestatin, a novel putative 23-amino acid peptide, is derived from mammalian preproghrelin gene via a bioinformatics approach. Although obestatin regulates thirst, sleep, memory, anxiety, activates cortical neurons in the brain and stimulate proliferation of retinal pigment epithelial cells, there is no study to explore its central impacts on the lower gut motility and secretion. We investigated the influence of intracerebroventricular (ICV) injection of obestatin on rat colonic motor and secretory functions. Colonic transit time, fecal pellet output and fecal content were assessed in freely fed, conscious rats, which were implanted with ICV and colonic catheters chronically. Human/rat corticotropin-releasing factor (h/rCRF) was applied as a stimulatory inducer of colonic motility and secretion. ICV injection of obestatin (0.1, 0.3, 1.0 nmol/rat) did not modify the colonic transit time, whereas ICV injection of h/rCRF (0.3 nmol/rat) significantly shortened colonic transit time. ICV obestatin in any dose we tested did not affect the fecal pellet output, frequency of watery diarrhea, total fecal weight, fecal dried solid weight, or fecal fluid weight in the first hour post-injection, either. In contrast, ICV injection of h/rCRF effectively stimulated fecal pellet output, as well as increased total fecal weight, fecal dried solid weight and fecal fluid weight during the first hour post-injection, compared to ICV saline controls. In conclusion, using our novel simultaneous measurement method, acutely central administration of obestatin exhibits no influence on colonic motility and secretion in conscious rats.

  15. A self-calibrating telemetry system for measurement of ventricular pressure-volume relations in conscious, freely moving rats.

    Science.gov (United States)

    Uemura, Kazunori; Kawada, Toru; Sugimachi, Masaru; Zheng, Can; Kashihara, Koji; Sato, Takayuki; Sunagawa, Kenji

    2004-12-01

    Using Bluetooth wireless technology, we developed an implantable telemetry system for measurement of the left ventricular pressure-volume relation in conscious, freely moving rats. The telemetry system consisted of a pressure-conductance catheter (1.8-Fr) connected to a small (14-g) fully implantable signal transmitter. To make the system fully telemetric, calibrations such as blood resistivity and parallel conductance were also conducted telemetrically. To estimate blood resistivity, we used four electrodes arranged 0.2 mm apart on the pressure-conductance catheter. To estimate parallel conductance, we used a dual-frequency method. We examined the accuracy of calibrations, stroke volume (SV) measurements, and the reproducibility of the telemetry. The blood resistivity estimated telemetrically agreed with that measured using an ex vivo cuvette method (y=1.09x - 11.9, r2= 0.88, n=10). Parallel conductance estimated by the dual-frequency (2 and 20 kHz) method correlated well with that measured by a conventional saline injection method (y=1.59x - 1.77, r2= 0.87, n=13). The telemetric SV closely correlated with the flowmetric SV during inferior vena cava occlusions (y=0.96x + 7.5, r2=0.96, n=4). In six conscious rats, differences between the repeated telemetries on different days (3 days apart on average) were reasonably small: 13% for end-diastolic volume, 20% for end-systolic volume, 28% for end-diastolic pressure, and 6% for end-systolic pressure. We conclude that the developed telemetry system enables us to estimate the pressure-volume relation with reasonable accuracy and reproducibility in conscious, untethered rats.

  16. Regional haemodynamic effects of carbachol injected into the hypothalamic paraventricular nuclei of conscious, unrestrained rats.

    Science.gov (United States)

    Bachelard, H; Gardiner, S M; Kemp, P A; Bennett, T

    1994-06-01

    Carbachol was injected into the hypothalamic paraventricular nuclei (PVN) of conscious, unrestrained Long Evans rats, chronically instrumented with intravascular catheters and pulsed Doppler probes to assess changes in regional haemodynamics. Bilateral microinjections of carbachol (1 ng-1 microgram) produced increases in blood pressure, bradycardias and vasoconstrictions in renal, superior mesenteric and hindquarters vascular beds. In the presence of phentolamine, the bradycardic and hindquarters vasoconstrictor responses to carbachol were unchanged while the pressor response was smaller due to a reduction in the renal and the superior mesenteric vasoconstriction. In the presence of propranolol, the bradycardic response was reduced, but the pressor and renal vasoconstrictor responses were potentiated, whereas the superior mesenteric and hindquarter vasoconstrictions were not changed significantly. In the presence of phentolamine and propranolol, the heart rate and pressor responses, as well as the renal vasoconstriction, were unchanged, whereas the superior mesenteric vasoconstriction was reduced and the hindquarters vasoconstriction was potentiated. Together these results are consistent with an involvement of the sympathoadrenal system in the pressor response to carbachol injected into the PVN of untreated animals. They indicate that alpha-adrenoceptor-mediated vasoconstriction in the superior mesenteric vascular bed is a particularly important component in that regard. In the presence of the vasopressin antagonist, d(CH2)5(Tyr(Et))DAVP, alone or in combination with phentolamine and propranolol, the pressor response to carbachol was substantially reduced, while the renal and superior mesenteric vasoconstrictor effects were completely abolished; the bradycardia was not significantly affected by this treatment. These results indicate an important involvement of vasopressin in the cardiovascular responses to carbachol injected into the PVN of untreated animals

  17. Influence of a multideficient diet from northeastern Brazil on resting blood pressure and baroreflex sensitivity in conscious, freely moving rats

    Directory of Open Access Journals (Sweden)

    F.M.F. Monteiro

    2001-02-01

    Full Text Available The "regional basic diet" or RBD is a multideficient diet (providing 8% protein which is known to produce dietary deficiencies in some populations in northeastern Brazil. The present study investigated the effects of RBD-induced malnutrition on resting blood pressure and baroreflex sensitivity in conscious rats. Malnourished rats were obtained by feeding dams the RBD during mating and pregnancy (RBD-1 group or during nursing and a 10-day period after weaning (RBD-2 group. At 90 days of age, only RBD-2 rats weighed significantly (P<0.001 less than control rats born to dams fed a standard commercial diet (23% protein during pregnancy and nursing. Baseline mean arterial pressure and heart rate of both RBD-1 and RBD-2 rats were comparable to those of controls. The slopes for both reflex bradycardia and tachycardia (bpm/mmHg induced by intravenous phenylephrine and sodium nitroprusside, respectively, were unchanged in either RBD-1 (-2.08 ± 0.11 and -3.10 ± 0.43, respectively or RBD-2 (-2.32 ± 0.30 and -3.73 ± 0.53, respectively rats, when compared to controls (-2.09 ± 0.10 and -3.17 ± 0.33, respectively. This study shows that, after a prolonged period of nutritional recovery, the patterns of resting blood pressure and baroreflex sensitivity of both pre- and postnatally malnourished rats were similar to those of controls. The decreased body weight and the tendency to increased reflex tachycardia in RBD-2 rats may suggest that this type of maternal malnutrition during lactation is more critical than during pregnancy.

  18. An Implanted Closed-loop Chip System for Heart Rate Control: System Design and Effects in Conscious Rats.

    Science.gov (United States)

    Zhou, Yuxuan; Yuan, Yuan; Gao, Juan; Yang, Ling; Zhang, Feng; Zhu, Guoqing; Gao, Xingya

    2010-03-01

    To evaluate the efficiency of an implanted chip system for the control of heart rate (HR). The HR was recorded in six conscious Sprague-Dawley (SD) rats. An implanted chip system was designed to regulate the HR by stimulating the right cervical vagus nerve according to the feedback of real time HR. Each rat was subjected to 30-min regulation and 30-min recovery. The change of HR during the regulation period was compared with the control. The ECG was recorded during the experiment for 24 h. The ECG signals were successfully recorded during the experiment. The HR was significantly decreased during the period of regulation compared with control (-79.3 ±34.5, P chip system can regulate the HR to a designated set point.

  19. Hepatic microvascular regulatory mechanisms. X. Effects of alpha-one or -two adrenoceptor blockade on glucoregulation in normotensive endotoxic rats with optimal perfusion and flowrates.

    Science.gov (United States)

    Reilly, F D; McCafferty, R E; Cilento, E V

    1988-08-01

    Circulating-blood glucose, hepatic glycogen distribution, and the glycogen contents of liver and skeletal muscle, were determined for 60 min in 31 fed and anesthetized Sprague-Dawley rats. These rats received an endoportal infusion of 15 mg per kg b.w. E. coli endotoxin (026:B6) or of sterile saline solution as a control. Either substance was given intravenously at 9:30 a.m. following an intraperitoneal injection at 9:00 a.m. of 0.1 mg per kg b.w. prazosin or 0.3 mg per kg b.w. yohimbine or of the carrier, distilled water. Infused endotoxin elevated blood glucose without affecting hepatic glycogen distribution and total glycogen contents of liver and skeletal muscle when compared to control. Prazosin inhibited endotoxin-induced hyperglycemia, and prazosin plus endotoxin provoked centrilobular glycogen depletion and decreased total hepatic glycogen content. However, no significant alteration in the glycogen content of skeletal muscle accompanied blockade of glucogenesis. Prazosin administered by itself produced no changes in hepatic and muscle glycogen. Although yohimbine blocked endotoxin-induced hyperglycemia, yohimbine, or yohimbine plus endotoxin, produced no significant change in the glycogen contents of liver and skeletal muscle. Blockade in the latter case was associated with some depletion of glycogen in hepatocytes dispersed randomly throughout the unit lobule and in cells located centrivenously. These results suggested that endotoxin-induced hyperglycemia is evoked by activation of alpha-1 and -2 adrenergic receptors. Since no detectible change in hepatic glycogen distribution and in the contents of liver and muscle glycogen accompanied glucogenesis, glycogen catabolism and deposition are postulated to proceed simultaneously and at equivalent rates by 60 min following the experimental induction of endotoxemia. Blockade of alpha (one or two) adrenoceptors is hypothesized to inhibit endotoxin-induced hyperglycemia by facilitating glucose utilization and not

  20. p38 MAPK mediates cardiovascular and behavioral responses induced by central IL-1β and footshock in conscious rats

    Institute of Scientific and Technical Information of China (English)

    Rui-mao ZHENG; Chang-jiang ZOU; Shi-gong ZHU

    2004-01-01

    AIM: To investigate the roles of p38 mitogen-activated protein kinase (p38 MAPK) in the cardiovascular and behavioral responses induced by intracerebral ventricular injection (icv) of interleukin- 1 β (IL- 1 β) or footshock.METHODS: We examined the effects of p38 MAPK on mean artery blood pressure (mABP), heart rate (HR), and motor activity (MA) during central administration of IL- 1 β, or footshock after icv SB203580 (a specific inhibitor of the p38 MAPK) with Cardiovascular and Behavior Telemetry System in conscious SD rats. RESULTS: (1) IL-1 β (icy) or footshock remarkably rise the mABP, and the maximal changes are (7.8± 1.8) and (12.3±3.5) mmHg,respectively, which was abrogated by the pretreatment with p38 inhibitor SB203580 intracerebroventricularly. (2)Compared with icv saline group, the motor activity was significantly decreased in SB203580 group with maximal changes (-7.6± 1.1) counts/min after footshock. CONCLUSION: p38 MAPK plays an important role in the pressor response induced by central administration of IL- 1 β or footshock and change of motor activity after footshock in conscious rats.

  1. Central nitric oxide modulates hindquarter vasodilation elicited by AMPA receptor stimulation in the NTS of conscious rats.

    Science.gov (United States)

    Dias, Ana Carolina Rodrigues; Colombari, Eduardo

    2006-05-01

    Microinjection of S-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) in the nucleus of the solitary tract (NTS) of conscious rats causes hypertension, bradycardia, and vasoconstriction in the renal, mesenteric, and hindquarter vascular beds. In the hindquarter, the initial vasoconstriction is followed by vasodilation with AMPA doses >5 pmol/100 nl. To test the hypothesis that this vasodilation is caused by activation of a nitroxidergic pathway in the NTS, we examined the effect of pretreatment with the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 10 nmol/100 nl, microinjected into the NTS) on changes in mean arterial pressure, heart rate, and regional vascular conductance (VC) induced by microinjection of AMPA (10 pmol/100 nl in the NTS) in conscious rats. AMPA increased hindquarter VC by 18 +/- 4%, but after pretreatment with L-NAME, AMPA reduced hindquarter VC by 16 +/- 7% and 17 +/- 9% (5 and 15 min after pretreatment, P NTS activates both vasodilatatory and vasoconstrictor mechanisms and that the vasodilatatory mechanism depends on production of nitric oxide in the NTS.

  2. Involvement of the dopaminergic system in the central orexin-induced antinociceptive action against colonic distension in conscious rats.

    Science.gov (United States)

    Okumura, Toshikatsu; Nozu, Tsukasa; Kumei, Shima; Takakusaki, Kaoru; Miyagishi, Saori; Ohhira, Masumi

    2015-09-25

    We have recently demonstrated that orexin acts centrally in the brain to induce antinociceptive action against colonic distension through orexin 1 receptors in conscious rats. Although the dopaminergic system can induce antinociceptive action for somatic pain, the association between changes in the dopaminergic system and visceral pain perception has not been investigated. In the present study, we hypothesized that the dopaminergic system may be involved in visceral nociception, and if so, the dopaminergic system may mediate the orexin-induced visceral antinociception. Visceral sensation was evaluated using the colonic distension-induced abdominal withdrawal reflex (AWR) in conscious rats. Intracisternal injection of D1 (SKF38398) or D2 (quinpirole) dopamine receptor agonist increased the threshold volume of colonic distension-induced AWR in a dose-dependent manner. Pretreatment with either the D1 or D2 dopamine receptor antagonist (SCH23390 or sulpiride, respectively) potently blocked the centrally injected orexin-A-induced antinociceptive action against colonic distension. These results suggest for the first time that dopaminergic signaling via D1 and D2 dopamine receptors in the brain may induce visceral antinociception and that the dopaminergic signaling may be involved in the central orexin-induced antinociceptive action against colonic distension.

  3. Rostral Ventrolateral Medulla EP3 Receptor Mediates the Sympathoexcitatory and Pressor Effects of Prostaglandin E2 in Conscious Rats.

    Science.gov (United States)

    Rezq, Samar; Abdel-Rahman, Abdel A

    2016-11-01

    Whereas few studies have dealt with the central sympathoexcitatory action of the inflammatory prostanoid prostaglandin E2 (PGE2), there is no information on the expression and cardiovascular function of different PGE2 (EP) receptors in one of the major cardiovascular-regulating nuclei, the rostral ventrolateral medulla (RVLM). The current study aimed at filling this knowledge gap as well as elucidating the implicated molecular mechanisms. To achieve these goals, we showed the expression of EP2, EP3, and EP4 receptors in the RVLM and investigated their cardiovascular roles in conscious rats, ex vivo as well as in cultured PC12 cells. Intra-RVLM PGE2 significantly increased blood pressure and sympathetic dominance (spectral analysis). Studies with selective EP receptor subtype agonists and antagonists showed that these PGE2-evoked responses were only replicated by intra-RVLM activation of the EP3 receptor with its agonist sulprostone. The RVLM of PGE2-treated rats exhibited increases in c-Fos expression and extracellular signal-regulated kinase 1/2 and neuronal nitric oxide synthase phosphorylation along with oxidative stress, and PGE2 increased l-glutamate release in PC12 cells (surrogates of RVLM neurons). Abrogation of the PGE2-evoked pressor and biochemical responses only occurred following EP3 receptor blockade (N-[(5-Bromo-2-methoxyphenyl)sulfonyl]-3-[2-(2-naphthalenylmethyl)phenyl]-2-propenamide, L-798106). These findings suggest the dependence of RVLM PGE2-mediated sympathoexcitation/pressor response on local EP3 receptor signaling in conscious rats, and highlight central EP3 receptor blockade as a potential therapeutic modality for hypertension management. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  4. Electrical stimulation of the aortic depressor nerve in conscious rats overcomes the attenuation of the baroreflex in chronic heart failure.

    Science.gov (United States)

    Pinto, Tomás O C Teixeira; Lataro, Renata M; Castania, Jaci A; Durand, Marina T; Silva, Carlos A A; Patel, Kaushik P; Fazan, Rubens; Salgado, Helio C

    2016-04-01

    Chronic heart failure (CHF) is characterized by autonomic dysfunction combined with baroreflex attenuation. The hypotensive and bradycardic responses produced by electrical stimulation of the aortic depressor nerve (ADN) were examined in conscious CHF and control male Wistar rats (12-13 wk old). Furthermore, the role of parasympathetic and sympathetic nervous system in mediating the cardiovascular responses to baroreflex activation was evaluated by selective β1-adrenergic and muscarinic receptor antagonists. CHF was induced by myocardial infarction. After 6 wk, the subjects were implanted with electrodes for ADN stimulation. Twenty-four hours later, electrical stimulation of the ADN was applied for 20 s using five different frequencies (5, 15, 30, 60, and 90 Hz), while the arterial pressure was recorded by a catheter implanted into the femoral artery. Electrical stimulation of the ADN elicited progressive and similar hypotensive and bradycardic responses in control (n = 12) and CHF (n = 11) rats, while the hypotensive response was not affected by methylatropine. Nevertheless, the reflex bradycardia was attenuated by methylatropine in control, but not in CHF rats. Atenolol did not affect the hypotensive or bradycardic response in either group. The ADN function was examined under anesthesia through electroneurographic recordings. The arterial pressure-ADN activity relationship was attenuated in CHF rats. In conclusion, despite the attenuation of baroreceptor function in CHF rats, the electrical stimulation of the ADN elicited a stimulus-dependent hypotension and bradycardia of similar magnitude as observed in control rats. Therefore, electrical activation of the aortic baroreflex overcomes both the attenuation of parasympathetic function and the sympathetic overdrive.

  5. Inactivation of neuronal function in the amygdaloid region reduces tail artery blood flow alerting responses in conscious rats.

    Science.gov (United States)

    Mohammed, M; Kulasekara, K; De Menezes, R C; Ootsuka, Y; Blessing, W W

    2013-01-03

    Few studies have investigated whether neuronal function in the amygdaloid complex is necessary for the occurrence of the cardiovascular response to natural (unconditioned) environmental threats. In the present investigation in conscious unrestrained Sprague-Dawley rats we inactivated neuronal function in the amygdaloid complex acutely (bilateral muscimol injections) or chronically (unilateral or bilateral ibotenic acid injections) and measured the effect on sudden falls in tail artery blood flow elicited by non-noxious salient stimuli (sympathetic cutaneous vasomotor alerting responses, SCVARs). After acute bilateral injection of vehicle (200nl Ringer's solution) the SCVAR index was 81 ± 2%, indicating that tail blood flow was reduced by 81% in response to the salient stimuli. After acute bilateral injection of muscimol (1 nmol in 200 nl of Ringer's solution) into the amygdaloid complex the SCVAR index was 49 ± 5%, indicating that tail blood flow was reduced by 49% in response to the salient stimuli (pbody with more immediate metabolic requirements.

  6. Temporary losartan or captopril in young SHR induces malignant hypertension despite initial normotension

    NARCIS (Netherlands)

    Racasan, S; Hahnel, B; van der Giezen, DM; Blezer, EL; Goldschmeding, R; Braam, B; Kriz, W; Koomans, HA; Joles, JA

    2004-01-01

    Background. Exposure of normotensive rats to angiotensin-converting enzyme (ACE) inhibitors in early life causes hypertrophy of intrarenal arteries. Similar defects have been found in knockout mice lacking angiotensinogen, ACE, or angiotensin II type 1 (AT(1)) receptors. On the other hand, transient

  7. Microinjection of muscimol into the periaqueductal gray suppresses cardiovascular and neuroendocrine response to air jet stress in conscious rats.

    Science.gov (United States)

    de Menezes, Rodrigo C A; Zaretsky, Dmitry V; Sarkar, Sumit; Fontes, Marco A P; Dimicco, Joseph A

    2008-09-01

    Microinjection of the neuronal inhibitor muscimol into the dorsomedial hypothalamus (DMH) suppresses increases in heart rate (HR), mean arterial pressure (MAP), and circulating levels of adrenocorticotropic hormone (ACTH) evoked in air jet stress in conscious rats. Similar injection of muscimol into the caudal region of the lateral/dorsolateral periaqueductal gray (l/dlPAG) reduces autonomic responses evoked from the DMH, leading to the suggestion that neurons in the l/dlPAG may represent a descending relay for DMH-induced increases in HR and MAP. Here, we examined the role of neuronal activity in the caudal l/dlPAG on the increases in MAP, HR, and plasma ACTH seen in air jet stress in rats. Microinjection of muscimol into the caudal l/dlPAG reduced stress-induced increases in HR and MAP, while identical injections into sites just dorsal or into the rostral l/dlPAG had no effect. Microinjection of a combination of the glutamate receptor antagonists 2-amino-5-phosphonopentanoate (AP5) and 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione (NBQX) into the caudal l/dlPAG decreased stress-induced increases in HR alone only at the end of the 20-min stress period but significantly accelerated return to baseline. Surprisingly, microinjection of muscimol into the caudal l/dlPAG also reduced the stress-induced increase in plasma ACTH by 51%. Compared with unstressed control rats, rats exposed to air jet stress exhibited approximately 3 times the number of Fos-positive neurons in the l/dlPAG. These findings suggest that neurons in the l/dlPAG are activated in air jet stress and that this activity contributes to increases in HR, MAP, and plasma ACTH.

  8. Telemetry-based oxygen sensor for continuous monitoring of kidney oxygenation in conscious rats

    National Research Council Canada - National Science Library

    Maarten P. Koeners; Connie P. C. Ow; David M. Russell; Amany Abdelkader; Gabriela A. Eppel; John Ludbrook; Simon C. Malpas; Roger G. Evans

    2013-01-01

    ...). After acute implantation in anesthetized rats, tissue Po2 measured by CPE-telemetry in the inner cortex and medulla was in close agreement with that provided by the “gold standard” Clark electrode...

  9. Endogenous excitatory amino acid neurotransmission regulates thyroid-stimulating hormone and thyroid hormone secretion in conscious freely moving male rats.

    Science.gov (United States)

    Arufe, M C; Durán, R; Perez-Vences, D; Alfonso, M

    2002-04-01

    The role of neurotransmission of endogenous excitatory amino acid (EAA) on serum thyroid hormones and thyroid-stimulating hormone (TSH) levels was examined in conscious and freely moving adult male Sprague-Dawley rats. The rats were cannulated at the third ventricle 2 d before the experiments. Several glutamate receptor agonists, such as kainic acid and domoic acid, and antagonists, such as 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and dizocilpine (MK-801) were administered into the third ventricle. Serum TSH levels were assesed by radioimmunoassay, and serum thyroid hormone levels were assessed by enzyme immunoassay. The results showed that the administration of CNQX and MK-801 produced a decrease in serum levels of TSH and thyroid hormones. The administration of kainic acid and domoic acid increased TSH concentrations, whereas CNQX completely blocked the release of TSH induced by kainic acid and domoic acid. These results suggest the importance of endogenous EAA in the regulation of hormone secretion from the pituitary-thyroid axis, as well as the role of the N-methyl-D-aspartate (NMDA) and non-NMDA receptors in the stimulatory effect of EAAs on the pituitary-thyroid axis.

  10. Potentiation of Hormonal Responses to Hemorrhage and Fasting, but not Hypoglycemia in Conscious Adrenalectomized Rats

    Science.gov (United States)

    Darlington, Daniel N.; Keil, Lanny C.; Dallman, Mary F.

    1989-01-01

    Bilateral adrenalectomy (ADRX) in rats removes the source of two major stress-responsive hormones, corticosterone and epinephrine. To test how ADRX rats with-stand stress, we performed the following experiments in adult male rats provided with indwelling femoral arterial and venous cannulae and either ADRX or sham-adrenalectomized (Sham) 3 days later and given 0.5% NaCl to drink. Five to 6 days after adrenal surgery the rats were studied after either a 15 ml/kg.5 min hemorrhage or after an overnight fast followed by insulin-induced hypoglycemia. In fed unstressed ADRX rats, basal mean arterial blood pressure was slightly decreased; heart rate was increased; blood volume, vasopressin, and oxytocin concentrations were not different from sham values; and renin and norepinephrine were significantly elevated. The recovery of arterial pressure after hemorrhage in the ADRX rats was similar to that in the sham group over a 5-h period; however, the responses of vasopressin and oxytocin were significantly greater, and those of renin and norepinephrine were markedly potentiated in the ADRX group. Heart rate recovered faster in the ADRX group and was elevated, compared to the sham value, for most of the 5-h period. Restitution of blood volume was attenuated in the ADRX group, although the restitution of plasma protein was not different between the groups. A significant difference in the change in plasma osmolality between groups after hemorrhage may account for the attenuated restitution of blood volume. After an overnight fast, which reduced blood volume in both groups of rats, the plasma renin concentration rose still further in ADRX rats; the differences in other measured variables observed between fed ADRX and sham groups remained the same. The insulin-induced 50% decrease in glucose caused minor effects on arterial blood pressure and heart rate and occasioned responses in renin and norepinephrine of similar magnitudes in the two groups. We conclude that in the absence of

  11. THE REGULATION OF DOPAMINE RELEASE FROM NIGROSTRIATAL NEURONS IN CONSCIOUS RATS - THE ROLE OF SOMATODENDRITIC AUTORECEPTORS

    NARCIS (Netherlands)

    SANTIAGO, M; WESTERINK, BHC

    1991-01-01

    Drugs were infused into the substantia nigra of the rat brain via a microdialysis probe, and the extracellular concentration of dopamine (DA) and 3,4-dihydroxyphenylacetic acid was recorded from a second dialysis probe implanted in the ipsilateral striatum. This approach allowed the evaluation of th

  12. Development of a Model for Nerve Agent Inhalation in Conscious Rats

    Science.gov (United States)

    2013-05-23

    Toxicol Mech Meth 14:183–94. Bajgar J. (2004). Organophosphates /nerve agent poisoning : mechanism of action, diagnosis, prophylaxis, and treatment. Adv...See reprint. 15. SUBJECT TERMS Chemical warfare, cholinesterases, inhalation exposure, nerve agents, organophosphates , vapor 16. SECURITY...exposure system for assessing respiratory toxicity of vaporized chemical agents in untreated, non-anesthetized rats. The organophosphate diisopropyl

  13. Inhibition of mineralocorticoid receptors with eplerenone alleviates short-term cyclosporin A nephrotoxicity in conscious rats

    DEFF Research Database (Denmark)

    Nielsen, Finn Thomsen; Jensen, Boye L; Marcussen, Niels

    2008-01-01

    BACKGROUND: Recent data indicate that aldosterone aggravates cyclosporin A (CsA)-induced nephrotoxicity. We examined whether the mineralocorticoid receptor (MR) blocker eplerenone (EPL) antagonized early deterioration of renal function and blood pressure (BP) increase in CsA-treated rats. METHODS...

  14. Effect of the Combination of Glibenclamide, an ATP-dependent Potassium Channel Blocker, and Metoprolol, a Cardioselective b-adrenoceptor Blocker, During Myocardial Infarction in Conscious Rats

    OpenAIRE

    BOZDOĞAN, Ömer

    2000-01-01

    We investigated the possible interaction of glibenclamide and metoprolol on the occurrence of life threatening arrhythmias during the acute phase of experimental myocardial infarction. Coronary artery ligation was performed in conscious rats and ECG was recorded for 15 min following ligation. Neither metoprolol (2 mg/kg i.p., 20 min before coronary artery ligation), nor glibenclamide (5 mg/kg i.p., 30 min before ligation) pretreatment increased significantly the survival rate durin...

  15. Nimodipine pretreatment improves cerebral blood flow and reduces brain edema in conscious rats subjected to focal cerebral ischemia.

    Science.gov (United States)

    Jacewicz, M; Brint, S; Tanabe, J; Wang, X J; Pulsinelli, W A

    1990-11-01

    The effect of nimodipine pretreatment on CBF and brain edema was studied in conscious rats subjected to 2.5 h of focal cortical ischemia. An infusion of nimodipine (2 micrograms/kg/min i.v.) or its vehicle, polyethylene glycol 400, was begun 2 h before the ischemic interval and was continued throughout the survival period. Under brief halothane anesthesia, the animals' right middle cerebral and common carotid arteries were permanently occluded, and 2.5 h later, they underwent a quantitative CBF study ([14C]iodoantipyrine autoradiography followed by Quantimet 970 image analysis). Nimodipine treatment improved blood flow to the middle cerebral artery territory without evidence of a "vascular steal" and reduced the volume of the ischemic core (cortex with CBF of less than 25 ml/100 g/min) and accompanying edema by approximately 50% when compared with controls (p = 0.006 and 0.0004, respectively). Mild hypotension induced by nimodipine did not aggravate the ischemic insult. The ischemic core volumes, however, were 50-75% smaller than the 24-h infarct volumes generated in a similar paradigm that demonstrated 20-30% infarct reduction with continuous nimodipine treatment. These results suggest that nimodipine pretreatment attenuates the severity of early focal cerebral ischemia, but that with persistent ischemia, cortex surrounding the ischemic core undergoes progressive infarction and the early benefit of nimodipine treatment is only partly preserved.

  16. Central vagal stimulation activates enteric cholinergic neurons in the stomach and VIP neurons in the duodenum in conscious rats.

    Science.gov (United States)

    Yuan, Pu-Qing; Kimura, Hiroshi; Million, Mulugeta; Bellier, Jean-Pierre; Wang, Lixin; Ohning, Gordon V; Taché, Yvette

    2005-04-01

    The influence of central vagal stimulation induced by 2h cold exposure or intracisternal injection of thyrotropin-releasing hormone (TRH) analog, RX-77368, on gastro-duodenal enteric cholinergic neuronal activity was assessed in conscious rats with Fos and peripheral choline acetyltransferase (pChAT) immunoreactivity (IR). pChAT-IR was detected in 68%, 70% and 73% of corpus, antrum and duodenum submucosal neurons, respectively, and in 65% of gastric and 46% of duodenal myenteric neurons. Cold and RX-77368 induced Fos-IR in over 90% of gastric submucosal and myenteric neurons, while in duodenum only 25-27% of submucosal and 50-51% myenteric duodenal neurons were Fos positive. In the stomach, cold induced Fos-IR in 93% of submucosal and 97% of myenteric pChAT-IR neurons, while in the duodenum only 7% submucosal and 5% myenteric pChAT-IR neurons were Fos positive. In the duodenum, cold induced Fos in 91% of submucosal and 99% of myenteric VIP-IR neurons. RX-77368 induces similar percentages of Fos/pChAT-IR and Fos/VIP-IR neurons. These results indicate that increased central vagal outflow activates cholinergic neurons in the stomach while in the duodenum, VIP neurons are preferentially stimulated.

  17. Reduction of myocardial infarction and dysrhythmic activity by nafazatrom in the conscious rat.

    Science.gov (United States)

    Fiedler, V B

    1983-03-25

    The effects of nafazatrom (30 and 100 mg/kg b.i.d.) on myocardial lesions caused by coronary artery ligation were determined in rats. The treatment lasted ten days preceding and twenty days following the cardiac insult, and its effects were compared with the effects of oral 1% Tylose suspension as drug vehicle. Nafazatrom reduced the number of extrasystoles and the duration of ventricular tachycardia and fibrillation occurring in the early (0-10 min) and late phases (2-4 h) of cardiac arrhythmias observed in the controls. Pretreatment with nafazatrom reduced the size of the ultimate infarct by 36 and 48 percent (P less than 0.05), and by 28 and 39% (P less than 0.05) with post-ligature nafazatrom treatment.

  18. The effect of Quinpirol and Sulpiride on the brain activity waves in conscious and aneasthetized rat

    Directory of Open Access Journals (Sweden)

    Komaki AR

    1998-06-01

    Full Text Available Brain's waves are produced by spontaneous activity of neurons. These waves are changed by neurotransmitters in the central nervous system (CNS. Concentration of these neurotransmitters can be changed by various drugs and total power of brain waves also increase or decrease by these drugs. In this research effect of Quinpirol and Sulpiride on the brain waves was investigated. Male wistar rats (weight 190-230 were aneasthetized with thiopental and two holes were made into the frontal and occipital area and two Ag/AgCl electrodes were fixed into these holes. One week after recovery, two electrodes were connected to the physiograph and the results were analyzed before and after intraperitoneal and intracerebroventricular (ICV injection of drugs by PC computer. Our results showed that intraperitoneal administration (5 mg/kg of diazepam reduced the depth of anesthesia. Conversely, intracerebroventricular injection of sulpiride increased the depth of anesthesia which was manifested by an increase in relative power of delta waves and reduction of relative power of alpha waves. This drug had a biphasic effect on EEG, at high doses in increased the depth of aneasthesia and total sleep. Wehteas depth of anesthesia was decreased at low dose. Simutanuos administration of sulpiride and quinpirole produced an effect on EEG similar to diazepam. As a result, biphasic effect of D2 agonist and antagonist drugs on brain waves are due to nonspecific action of these drugs on these receptors and this effect may be produced by other mechanisms

  19. Epileptic seizure-induced hypertension and its prevention by calcium channel blockers: a real-time study in conscious telemetered rats.

    Science.gov (United States)

    Beig, Mirza Irfan; Chandra, Ramesh; Talwar, Anita; Fahim, Mohammad; Katyal, Anju

    2009-07-01

    Epileptic seizures are accompanied by changes in autonomic function that in turn influence the cardiovascular system (hypertension and bradyarrhythmia). We have studied possible cardioprotective activity (during the ictal state in conscious animals) of valproic acid, nifedipine, and verapamil, alone and in combination, during pentylenetetrazole (PTZ)-induced seizures. Telemetry system was used for recording EEG, blood pressure, and heart rate in conscious, freely moving rats during seizures. We observed that PTZ-induced seizures were accompanied by hypertension and bradyarrhythmia. Pretreatment with valproic acid did not block seizure-induced hypertension and bradyarrhythmia. Nifedipine alone and in combination with valproic acid blocked seizure-induced hypertension and bradyarrhythmia significantly. We also observed that pretreatment with verapamil alone and in combination with valproic acid did not block seizure-induced hypertension and bradyarrhythmia significantly. Our results suggest that pretreatment with nifedipine alone or in combination with valproic acid provides protection against seizure-induced hypertension and bradyarrhythmia.

  20. Roles of forebrain GABA receptors in controlling vasopressin secretion and related phenomena under basal and hyperosmotic circumstances in conscious rats.

    Science.gov (United States)

    Yamaguchi, Ken'ichi; Yamada, Takaho

    2008-09-05

    Although the anteroventral third ventricular region (AV3V), a forebrain area essential for homeostatic responses, includes receptors for gamma-aminobutyric acid (GABA), the roles of these receptors in controlling vasopressin (AVP) secretion and related phenomena have not been clarified as yet. This study aimed to pursue this problem in conscious rats implanted with indwelling catheters. Cerebral injection sites were determined histologically. Applications of bicuculline, a GABA(A) receptor antagonist, to the AV3V induced prompt and marked augmentations in plasma AVP, osmolality, glucose, arterial pressure and heart rate, without affecting plasma electrolytes. Such phenomena did not occur when phaclofen, a GABA(B) receptor antagonist, was applied to the AV3V. All of the effects of AV3V-administered bicuculline were abolished by preadministration of the GABA(A) receptor agonist muscimol. Preadministration of either MK-801 or NBQX, ionotropic glutamatergic receptor antagonists, was also potent to abolish the AVP response to AV3V bicuculline. When hypertonic saline was infused intravenously, plasma AVP increased progressively, in parallel with rises in plasma osmolality, sodium and arterial pressure. AV3V application of muscimol or baclofen, a GABA(B) receptor agonist, was found to abolish the response of plasma AVP, without inhibiting that of the osmolality or sodium. The response of arterial pressure was also blocked by muscimol treatment, but not by baclofen treatment. Based on these results, we concluded that, under basal conditions, GABA receptors in the AV3V or vicinity may tonically operate to attenuate AVP secretion and cardiovascular functions through mechanisms associated with glutamatergic activity, and that plasma hyperosmolality may cause facilitation of AVP release by decreasing forebrain GABAergic activity.

  1. Cyclosporine induces progressive attenuation of baroreceptor heart rate response and cumulative pressor response in conscious unrestrained rats.

    Science.gov (United States)

    Shaltout, Hossam A; Abdel-Rahman, Abdel A

    2003-06-01

    Cyclosporine A (CsA) use is associated with hypertension and reduced baroreceptor sensitivity (BRS), but the underlying mechanisms remain unresolved. In this study, we investigated whether CsA attenuation of BRS is 1) dependent on treatment regimen, and 2) causative of the pressor response. Furthermore, we investigated whether a reduction in plasma testosterone contributes to BRS attenuation caused by short-term CsA administration. The effects of the clinically used CsA formulation (15 mg/kg/day i.v. for 5 days) on mean arterial pressure (MAP), heart rate, BRS, and body weight were investigated in conscious rats. CsA caused reproducible pressor responses (15.1 +/- 3.0 mm Hg) starting after the first dose and continuing through the 5 days of the study. BRS and baseline MAP were inversely related in the CsA group because of a progressive reduction in BRS, which started on day 2 and reached approximately 50% of baseline on day 5 and a cumulative elevation in MAP. The inverse BRS and MAP responses required daily administration of CsA because neither response was evident throughout the 5-day observation period after a single dose of CsA. Plasma testosterone levels were similar in all groups, whereas the body weight decreased approximately 10% in the CsA group on day 5. These findings suggest 1) CsA attenuation of BRS is relatively rapid and cumulative; 2) the attenuation of BRS may contribute to the delayed, but not to the acute, pressor elicited by CsA; and 3) the cumulative reduction in BRS caused by short-term (5-day) CsA treatment is not testosterone-related.

  2. MODELING CONSCIOUSNESS

    OpenAIRE

    Taylor, J G

    2009-01-01

    We present tentative answers to three questions: firstly, what is to be assumed about the structure of the brain in attacking the problem of modeling consciousness; secondly, what is it about consciousness that is attempting to be modeled; and finally, what is taken on board the modeling enterprise, if anything, from the vast works by philosophers about the nature of mind.

  3. Levodopa acts centrally to induce an antinociceptive action against colonic distension through activation of D2 dopamine receptors and the orexinergic system in the brain in conscious rats

    Directory of Open Access Journals (Sweden)

    Toshikatsu Okumura

    2016-02-01

    Subcutaneously (80 mg/rat or intracisternally (2.5 μg/rat administered levodopa significantly increased the threshold of colonic distension-induced AWR in conscious rats. The dose difference to induce the antinociceptive action suggests levodopa acts centrally to exert its antinociceptive action against colonic distension. While neither sulpiride, a D2 dopamine receptor antagonist, nor SCH23390, a D1 dopamine receptor antagonist by itself changed the threshold of colonic distension-induced AWR, the intracisternally injected levodopa-induced antinociceptive action was significantly blocked by pretreatment with subcutaneously administered sulpiride but not SCH23390. Treatment with intracisternal SB334867, an orexin 1 receptor antagonist, significantly blocked the subcutaneously administered levodopa-induced antinociceptive action. These results suggest that levodopa acts centrally to induce an antinociceptive action against colonic distension through activation of D2 dopamine receptors and the orexinergic system in the brain.

  4. Control consciousness.

    Science.gov (United States)

    Mandik, Pete

    2010-10-01

    Control consciousness is the awareness or experience of seeming to be in control of one's actions. One view, which I will be arguing against in the present paper, is that control consciousness is a form of sensory consciousness. In such a view, control consciousness is exhausted by sensory elements such as tactile and proprioceptive information. An opposing view, which I will be arguing for, is that sensory elements cannot be the whole story and must be supplemented by direct contributions of nonsensory, motor elements. More specifically, I will be arguing for the view that the neural basis of control consciousness is constituted by states of recurrent activation in relatively intermediate levels of the motor hierarchy. Copyright © 2010 Cognitive Science Society, Inc.

  5. Conscious Belief

    Directory of Open Access Journals (Sweden)

    David Pitt

    2016-04-01

    Full Text Available Tim Crane maintains that beliefs cannot be conscious because they persist in the absence of consciousness. Conscious judgments can share their contents with beliefs, and their occurrence can be evidence for what one believes; but they cannot be beliefs, because they don’t persist. I challenge Crane’s premise that belief attributions to the temporarily unconscious are literally true. To say of an unconscious agent that she believes that p is like saying that she sings well. To say she sings well is to say that when she sings, her singing is good. To say that she believes that p is (roughly to say that when she consciously considers the content that p she consciously affirms (believes it. I also argue that the phenomenal view of intentional content Crane appears to endorse prima facie commits him to the view, at least controversial, perhaps incoherent, that there is unconscious phenomenology (the intentional contents of unconscious beliefs.

  6. A pivotal role for enhanced brainstem Orexin receptor 1 signaling in the central cannabinoid receptor 1-mediated pressor response in conscious rats.

    Science.gov (United States)

    Ibrahim, Badr Mostafa; Abdel-Rahman, Abdel A

    2015-10-05

    Orexin receptor 1 (OX1R) signaling is implicated in cannabinoid receptor 1 (CB1R) modulation of feeding. Further, our studies established the dependence of the central CB1R-mediated pressor response on neuronal nitric oxide synthase (nNOS) and extracellular signal-regulated kinase1/2 (ERK1/2) phosphorylation in the RVLM. Here, we tested the novel hypothesis that brainstem orexin-A/OX1R signaling plays a pivotal role in the central CB1R-mediated pressor response. Our multiple labeling immunofluorescence findings revealed co-localization of CB1R, OX1R and the peptide orexin-A within the C1 area of the rostral ventrolateral medulla (RVLM). Activation of central CB1R following intracisternal (i.c.) WIN55,212-2 (15μg/rat) in conscious rats caused significant increases in BP and orexin-A level in RVLM neuronal tissue. Additional studies established a causal role for orexin-A in the central CB1R-mediated pressor response because (i) selective blockade of central CB1R (AM251, 30μg/rat; i.c.) abrogated WIN55,212-2-evoked increases in RVLM orexin-A level, (ii) the selective OX1R antagonist SB-408124 (10nmol/rat; i.c.) attenuated orexin-A (3nmol/rat; i.c.) or WIN55,212-2 (15μg/rat; i.c.)-evoked pressor response while selective CB1R blockade (AM251) had no effect on orexin-A (3nmol/rat; i.c.)-evoked pressor response, (iii) direct CB1R activation in the RVLM (WIN55,212-2; 0.1μg/rat) increased RVLM orexin-A and BP. Finally, SB-408124 attenuated WIN55,212-2-evoked increases in RVLM nNOS and ERK1/2 phosphorylation and BP. Our findings suggest that orexin-A/OX1R dependent activation of the RVLM nNOS/ERK1/2 cascade is essential neurochemical mechanism for the central CB1R-mediated pressor response in conscious rats.

  7. Functional imaging of focal brain activation in conscious rats: impact of [(14)C]glucose metabolite spreading and release.

    Science.gov (United States)

    Cruz, Nancy F; Ball, Kelly K; Dienel, Gerald A

    2007-11-15

    Labeled glucose and its analogs are widely used in imaging and metabolic studies of brain function, astrocyte-neuron interactions, and neurotransmission. Metabolite shuttling among astrocytes and neurons is essential for cell-cell transfer of neurotransmitter precursors and supply and elimination of energy metabolites, but dispersion and release of labeled compounds from activated tissue would reduce signal registration in metabolic labeling studies, causing underestimation of focal functional activation. Processes and pathways involved in metabolite trafficking and release were therefore assessed in the auditory pathway of conscious rats. Unilateral monotonic stimulation increased glucose utilization (CMR(glc)) in tonotopic bands in the activated inferior colliculus by 35-85% compared with contralateral tissue when assayed with [(14)C]deoxyglucose (DG), whereas only 20-30% increases were registered with [1- or 6-(14)C]glucose. Tonotopic bands were not evident with [1-(14)C]glucose unless assayed during halothane anesthesia or pretreatment with probenecid but were detectable with [6-(14)C]glucose. Extracellular lactate levels transiently doubled during acoustic stimulation, so metabolite spreading was assessed by microinfusion of [(14)C]tracers into the inferior colliculus. The volume of tissue labeled by [1-(14)C]glucose exceeded that by [(14)C]DG by 3.2- and 1.4-fold during rest and acoustic activation, respectively. During activation, the tissue volume labeled by U-(14)C-labeled glutamine and lactate rose, whereas that by glucose fell 50% and that by DG was unchanged. Dispersion of [1-(14)C]glucose and its metabolites during rest was also reduced 50% by preinfusion of gap junction blockers. To summarize, during brain activation focal CMR(glc) is underestimated with labeled glucose because of decarboxylation reactions, spreading within tissue and via the astrocyte syncytium, and release from activated tissue. These findings help explain the fall in CMR(O2)/CMR

  8. Occupational Consciousness.

    Science.gov (United States)

    Ramugondo, Elelwani L

    2015-10-02

    Occupational consciousness refers to ongoing awareness of the dynamics of hegemony and recognition that dominant practices are sustained through what people do every day, with implications for personal and collective health. The emergence of the construct in post-apartheid South Africa signifies the country's ongoing struggle with negotiating long-standing dynamics of power that were laid down during colonialism, and maintained under black majority rule. Consciousness, a key component of the new terminology, is framed from post-colonial perspectives - notably work by Biko and Fanon - and grounded in the philosophy of liberation, in order to draw attention to continuing unequal intersubjective relations that play out through human occupation. The paper also draws important links between occupational consciousness and other related constructs, namely occupational possibilities, occupational choice, occupational apartheid, and collective occupation. The use of the term 'consciousness' in sociology, with related or different meanings, is also explored. Occupational consciousness is then advanced as a critical notion that frames everyday doing as a potentially liberating response to oppressive social structures. This paper advances theorizing as a scholarly practice in occupational science, and could potentially expand inter or transdisciplinary work for critical conceptualizations of human occupation.

  9. Creative Consciousness

    Directory of Open Access Journals (Sweden)

    Ashok Natarajan

    2013-09-01

    Full Text Available Consciousness is creative. That creativity expresses in myriad ways – as moments in time in which decades of progress can be achieved overnight, as organizational innovations of immense power for social accomplishment; as creative social values that further influence the evolution of organizations and society; as the creativity of individuality in the leader, genius, artist and inventor; as social creativity that converts raw human experience into civilization; as cultural creativity that transforms human relationships into sources of rich emotional capacity; and as value-based educational creativity that can awaken and nurture young minds to develop and discover their own inherent capacity for knowledge in freedom. Through such moments do society and humanity evolve. Education is society’s most advanced institution for conscious social evolution. Values are the essence of society’s knowledge for highest accomplishment. Education that imparts values is an evolutionary social organization that can hasten the emergence of that creative consciousness.

  10. Consciousness extended

    DEFF Research Database (Denmark)

    Carrara-Augustenborg, Claudia

    2012-01-01

    There is no consensus yet regarding a conceptualization of consciousness able to accommodate all the features of such complex phenomenon. Different theoretical and empirical models lend strength to both the occurrence of a non-accessible informational broadcast, and to the mobilization of specific...... brain areas responsible for the emergence of the individual´s explicit and variable access to given segments of such broadcast. Rather than advocating one model over others, this chapter proposes to broaden the conceptualization of consciousness by letting it embrace both mechanisms. Within...... such extended framework, I propose conceptual and functional distinctions between consciousness (global broadcast of information), awareness (individual´s ability to access the content of such broadcast) and unconsciousness (focally isolated neural activations). My hypothesis is that a demarcation in terms...

  11. [Risk profiles of hypertension in normotensive subjects].

    Science.gov (United States)

    Ducher, M; Fauvel, J P; Cerutti, C

    2003-01-01

    The aim of this study was to evaluate the influence of 10 factors suspected to be involved in hypertension genesis (age, body mass index, alcohol consumption, sodium to potassium urinary excretion ratio, systolic BP and heart rate response to mental stress, baroreflex sensitivity (BRS), job demand, job latitude (Karasec's questionnaire), and personality (Bortner's score). A cohort of 213 normotensive healthy subjects was followed during five years. Using K-means clustering technique we have defined 7 homogeneous groups of subjects. Four groups with different combinations of these factors had a significantly higher 5-year systolic BP increase. The common characteristic of these groups was a low BRS. In conclusion, cluster analysis is well suited to analyse combined effect of factors on hypertension genesis. Only low BRS seems to be the common factor involved in hypertension development.

  12. Demodernizing Consciousness

    Science.gov (United States)

    Berger, Peter L.; And Others

    1973-01-01

    Youth culture and counterculture in contemporary Western societies are complex phenomena that may be viewed from a variety of social science perspectives. The authors analyze these cultures as embodiments of demodernizing consciousness with which they hold they have considerable firsthand experience. (RJ)

  13. Body sodium/blood volume state in normotensive members of normotensive and hypertensive families.

    Science.gov (United States)

    Beretta-Piccoli, C; Fischbacher, A; Rothenbühler, A; Gerber, A; Weidmann, P

    1986-04-01

    Exchangeable sodium is lower than normal in young male patients with essential hypertension. This may reflect a primary abnormality of sodium metabolism, or natriuresis caused by sodium-independent elevation of arterial pressure. To investigate this question, 31 normotensive men with positive and 31 normotensive men with negative family history of essential hypertension were studied. Blood pressure tended to be higher in the former (121/78 +/- 9/8 (s.d.) versus 113/74 +/- 11/9 mmHg; P less than 0.005); mean age, urinary sodium or potassium excretion, plasma sodium, potassium, renin activity or aldosterone levels and creatinine clearance were comparable. Exchangeable sodium and blood volume were also similar in the two groups, when expressed in absolute values (3113 +/- 306 versus 3044 +/- 242 mmol and 4902 +/- 581 versus 4769 +/- 579 ml, respectively) or in relation to body surface area (100.8 +/- 7.1 versus 100.2 +/- 6% and 103.8 +/- 12.2 versus 102 +/- 11.3%). In both groups, exchangeable sodium and blood volume were unrelated to arterial pressure. The body sodium/blood volume state is normal in normotensive subjects with positive family history. The low exchangeable sodium of young patients with essential hypertension does not appear to reflect a primary familial abnormality of body sodium metabolism.

  14. Creative Consciousness

    OpenAIRE

    Ashok Natarajan

    2013-01-01

    Consciousness is creative. That creativity expresses in myriad ways – as moments in time in which decades of progress can be achieved overnight, as organizational innovations of immense power for social accomplishment; as creative social values that further influence the evolution of organizations and society; as the creativity of individuality in the leader, genius, artist and inventor; as social creativity that converts raw human experience into civilization; as cultural creativity that tra...

  15. Agential Self-consciousness : beyond conscious agency

    NARCIS (Netherlands)

    Bos, G.H.

    2013-01-01

    Although we perform many of our actions without much consciousness of these, occasionally we are explicitly conscious that we are doing something for a reason. Such consciousness I call ‘agential self-consciousness’. Since ages we have understood such agential self-consciousness in terms of the

  16. Agential Self-consciousness : beyond conscious agency

    NARCIS (Netherlands)

    Bos, G.H.

    2013-01-01

    Although we perform many of our actions without much consciousness of these, occasionally we are explicitly conscious that we are doing something for a reason. Such consciousness I call ‘agential self-consciousness’. Since ages we have understood such agential self-consciousness in terms of the self

  17. A method for unit recording in the lumbar spinal cord during locomotion of the conscious adult rat

    DEFF Research Database (Denmark)

    Berg, Rune W; Chen, Ming-Teh; Huang, Hsueh-Chen;

    2009-01-01

    Extracellular recordings from single units in the brain, for example the neocortex, have proven feasible in moving, awake rats, but have not yet been possible in the spinal cord. Single-unit activity during locomotor-like activity in reduced preparations from adult cats and rats have provided...

  18. Vascular Reactivity and Salt Sensitivity in Normotensive and ...

    African Journals Online (AJOL)

    normotensive (NT) Nigerian subjects took part in the study after informed ... Salt sensitivty was determined as a change in mean arterial blood pressure (ΔMABP) ... Systolic and diastolic hyperreactivity were higher among HT (49% and 39% ...

  19. Cerebrovascular CO2 reactivity in normotensive and hypertensive man

    DEFF Research Database (Denmark)

    Tominaga, S; Strandgaard, S; Uemura, K

    1976-01-01

    Cerebrovascular reactivity to CO2 inhalation and voluntary hyperventilation was studied in seven normotensive subjects and nine hypertensive patients without clinical or angiographical signs of arteriosclerosis. Cerebral blood flow (CBF) was measured by the intracarotid 133Xe clearance method and...

  20. Convulsant and Subconvulsant Doses of Norfloxacin in the Presence and Absence of Biphenylacetic Acid Alter Extracellular Hippocampal Glutamate but Not Gamma-Aminobutyric Acid Levels in Conscious Rats

    Science.gov (United States)

    Smolders, I.; Gousseau, C.; Marchand, S.; Couet, W.; Ebinger, G.; Michotte, Y.

    2002-01-01

    Fluoroquinolones are antibiotics with central excitatory side effects. These adverse effects presumably result from inhibition of γ-aminobutyric acid (GABA) binding to GABAA receptors. This GABA antagonistic effect is greatly potentiated by the active metabolite of fenbufen, biphenylacetic acid (BPAA). Nevertheless, it remains questionable whether GABA receptor antagonism alone can explain the convulsant activity potentials of these antimicrobial agents. The present study was undertaken to investigate the possible effects of norfloxacin, both in the absence and in the presence of BPAA, on the extracellular hippocampal levels of GABA and glutamate, the main central inhibitory and excitatory amino acid neurotransmitters, respectively. This in vivo microdialysis approach with conscious rats allows monitoring of behavioral alterations and concomitant transmitter modulation in the hippocampus. Peroral administration of 100 mg of BPAA per kg of body weight had no effect on behavior and did not significantly alter extracellular GABA or glutamate concentrations. Intravenous perfusion of 300 mg of norfloxacin per kg did not change the rat's behavior or the concomitant neurotransmitter levels in about half of the experiments, while the remaining animals exhibited severe seizures. These norfloxacin-induced convulsions did not affect extracellular hippocampal GABA levels but were accompanied by enhanced glutamate concentrations. Half of the rats receiving both 100 mg of BPAA per kg and 50 mg of norfloxacin per kg displayed lethal seizures, while the remaining animals showed no seizure-related behavior. In the latter subgroup, again no significant alterations in extracellular GABA levels were observed, but glutamate overflow remained significantly elevated for at least 3 h. In conclusion, norfloxacin exerts convulsant activity in rats, accompanied by elevations of extracellular hippocampal glutamate levels but not GABA levels, even in the presence of BPAA. PMID:11796360

  1. Uric Acid Levels in Normotensive Children of Hypertensive Parents

    Directory of Open Access Journals (Sweden)

    Ali Yildirim

    2015-01-01

    Full Text Available This study evaluated uric acid concentrations in normotensive children of parents with hypertension. Eighty normotensive children from families with and without a history of essential hypertension were included. Concentrations of lipid parameters and uric acid were compared. Demographic and anthropometric characteristics were similar in the groups. Systolic and diastolic blood pressure were higher in the normotensive children of parents with hypertension without statistically significant difference (P>0.05. Uric acid concentrations were higher in the normotensive children of parents with hypertension (4.61 versus 3.57 mg/dL, P10 years (P<0.01. Uric acid levels were significantly higher in all children with more pronounced difference after age 10 of years (P<0.001. Positive correlations were found between the level of serum uric acid and age, body weight, body mass index, and systolic and diastolic blood pressure in the normotensive children of parents. The higher uric acid levels in the normotensive children of hypertensive parents suggest that uric acid may be a predeterminant of hypertension. Monitoring of uric acid levels in these children may allow for prevention or earlier treatment of future hypertension.

  2. 清醒大鼠动脉压力感受性反射的功能研究%Arterial baroreflex function in conscious rats

    Institute of Scientific and Technical Information of China (English)

    苏定冯; 缪朝玉

    2002-01-01

    Arterial baroreflex (ABR) is a very important mechanism in the regulation of cardiovascular activities. As ABR function is largely inhibited by anesthesia, its measurement in conscious animal becomes important. The present review summarizes the works concerning ABR function in conscious rats completed in our department in the last 10 years. Firstly, a new method was established to measure arterial baroreflex-blood pressure control (ABR-BP).ABR-BP and baroreflex sensitivity measured with classic method are two different parts of the ABR function.Secondly, it was proposed that ABR function predicted the end-organ damage in hypertension. Thirdly, interrup tion of ABR induced severe end-organ damages. Increased blood pressure variability (BPV) and activation ofrenin angiotensin system were involved in the mechanisms underlying organ damages in sinoaortic denervation (SAD)rats. Fourthly, we propose that amelioration of ABR function may serve as a new strategy for improving the prognosis of cardiovascular diseases. Ketanserin improved the impaired ABR function in SHR. Finally, the possi bility to develop a strain of rats with spontaneous deficiency on ABR function is mentioned.%本文综述本室近10年来对清醒自由活动大鼠动脉压力感受性反射(ABR)的功能性研究.首先,建立了ABR对血压的控制(ABR-BP)的测量方法.ABR-BP是与用经典方法测量的ABR功能(ABR-HP)不同的成份.其次,我们的研究表明ABR功能与高血压的器官损伤有关.损毁ABR功能可导致严重的器官损伤.该损伤的机制与血压波动性增高、肾素血管紧张素系统激活有关.酮色林能改善ABR功能.基于对酮色林研究的结果,我们提出改善ABR功能可作为改善某些心血管疾病预后的新策略.最后,提到了我们正在进行中的自发性ABR功能缺陷大鼠的培育.

  3. Insulin sensitivity and hemodynamic responses to insulin in Wistar-Kyoto and spontaneously hypertensive rats.

    Science.gov (United States)

    Pître, M; Nadeau, A; Bachelard, H

    1996-10-01

    The insulin-mediated vasodilator effect has been proposed as an important physiological determinant of insulin action on glucose disposal in normotensive humans. The present study was designed to further examine the acute regional hemodynamic effects of insulin in different vascular beds and to explore the relationships between insulin vascular effects and insulin sensitivity during euglycemic hyperinsulinemic clamps in conscious normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). The rats were instrumented with intravascular catheters and pulsed Doppler flow probes to measure blood pressure, heart rate, and regional blood flows. In WKY rats, the euglycemic infusion of insulin (4 and 16 mU.kg-1.min-1) causes vasodilations in renal and hindquarter vascular beds but no changes in mean blood pressure, heart rate, or superior mesenteric vascular conductance. In contrast, in SHR, the same doses of insulin produce vasoconstrictions in superior mesenteric and hindquarter vascular beds and, at high doses, increase blood pressure. Moreover, at the lower dose of insulin tested, we found a reduction in the insulin sensitivity index in the SHR compared with the WKY rats. The present findings provide further evidence for an association between insulin sensitivity and insulin-mediated hemodynamic responses.

  4. Influência de vasoconstritores associados a anestésicos locais sobre a pressão arterial de ratos hipertensos e normotensos Influence of vasoconstrictors associated with local anesthetics on the arterial pressure of hypertensive and normotensive rats

    Directory of Open Access Journals (Sweden)

    Apparecido Neri Daniel

    1999-07-01

    Full Text Available A utilização de anestésicos locais associados a vasoconstritores em pacientes hipertensos é controversa. Neste estudo, verificamos a influência desta associação sobre a pressão arterial caudal (PA em ratos hipertensos DOCA-sal. Após ligeira anestesia com éter, os anestésicos GRUPO I - lidocaína 2% sem vasoconstritor, GRUPO II - lidocaína com fenilefrina, GRUPO III - lidocaína a 2% com noradrenalina, GRUPO IV - prilocaína 3% com felipressina, GRUPO V - mepivacaína 2% com adrenalina e GRUPO VI - mepivacaína com noradrenalina foram injetados na submucosa da boca (anestesia infiltrativa, em ratos DOCA-sal e controles. A PA foi determinada 5 e 15 minutos após a primeira dose do anestésico e também 5 e 15 minutos após a segunda dose. Os dados obtidos indicaram que: a a PA dos ratos DOCA-sal (193,05 ± 4,25 mmHg; n = 43 foi significativamente superior àquela observada nos animais controles (115,64 ± 2,47 mmHg; n = 43 e, b não houve variação significativa nas PA observadas em animais DOCA-sal e controles pela administração dos anestésicos locais testados. Assim, nossos dados experimentais sugerem que a presença de agentes vasoconstritores associados à lidocaína 2%, à prilocaína 3% e à mepivacaína 2% não interferem na PA desses animais, neste modelo experimental de hipertensão.The utilization of local anesthetics associated with vasoconstrictors in hypertensive patients is controversial. The purpose of this investigation was to verify the influence of this association on the arterial pressure (AP in DOCA-salt hypertensive rats. After light ether anesthesia, the anesthetics (Group I - lidocaine 2% without vasoconstrictor; Group II - lidocaine 2% with phenylephrine, Group III - lidocaine 2% with noradrenaline- Group IV - prylocaine 3% with felypressin; Group V - mepivacaine 2% with epinephrine, and Group VI - mepivacaine 2% with norepinephrine were injected into mucobuccal fold (infiltration anesthesia, in DOCA

  5. Exogenous and endogenous angiotensin-II decrease renal cortical oxygen tension in conscious rats by limiting renal blood flow

    NARCIS (Netherlands)

    Emans, Tonja W.; Janssen, Ben J.; Pinkham, Maximilian I.; Ow, Connie P C; Evans, Roger G.; Joles, Jaap A.; Malpas, Simon C.; Krediet, C. T Paul; Koeners, Maarten P.

    2016-01-01

    Key points: Our understanding of the mechanisms underlying the role of hypoxia in the initiation and progression of renal disease remains rudimentary.  We have developed a method that allows wireless measurement of renal tissue oxygen tension in unrestrained rats.  This method provides stable and

  6. Intracisternally Injected L-Proline Activates Hypothalamic Supraoptic, but Not Paraventricular, Vasopressin-Expressing Neurons in Conscious Rats

    Directory of Open Access Journals (Sweden)

    Yumi Takemoto

    2011-01-01

    Full Text Available When injected into specific rat brain regions, the neurotransmitter candidate L-proline produces various cardiovascular changes through ionotropic excitatory amino acid receptors. The present study used an immunohistochemical double-labeling approach to determine whether intracisternally injected L-proline in freely moving rats, which increases blood pressure, activates hypothalamic vasopressin-expressing neurons and ventral medullary tyrosine-hydroxylase- (TH- containing neurons. Following injection of L-proline, the number of activated hypothalamic neurons that coexpressed vasopressin and c-Fos was much greater in the supraoptic nucleus (SON than in the paraventricular nucleus (PVN of rats with increased blood pressure. The number of activated TH-containing neurons was significantly greater following L-proline treatment than following control injections of artificial cerebrospinal fluid (ACSF. These results clearly demonstrate that intracisternally injected L-proline activates hypothalamic supraoptic, but not paraventricular, vasopressin-expressing neurons and medullary TH-containing (A1/C1 neurons in freely moving rats.

  7. Salt sensitivity of renin secretion, glomerular filtration rate and blood pressure in conscious Sprague-Dawley rats

    DEFF Research Database (Denmark)

    Isaksson, G L; Stubbe, J; Hansen, Per Lyngs;

    2014-01-01

    We hypothesized that in normal rats in metabolic steady state, (i) the plasma renin concentration (PRC) is log-linearly related to Na(+) intake (NaI), (ii) the concurrent changes in mean arterial pressure (MABP) and glomerular filtration rate (GFR) are negligible and (iii) the function PRC = f(Na...... = f(NaI) is altered by β1 -adrenoceptor blockade (metoprolol) and surgical renal denervation (DNX)....

  8. Restoration of visual performance by d-serine in models of inner and outer retinal dysfunction assessed using sweep VEP measurements in the conscious rat and rabbit.

    Science.gov (United States)

    Staubli, Ursula; Rangel-Diaz, Natalie; Alcantara, Miguel; Li, Yong-Xin; Yang, Jia-Ying; Zhang, Kai-Ming; Foster, Alan C

    2016-10-01

    The NMDA subtype of glutamate receptor and its co-agonist d-serine play a key role in synaptic function in the central nervous system (CNS), including visual cortex and retina. In retinal diseases such as glaucoma and macular degeneration, a loss of vision arises from malfunction of retinal cells, resulting in a glutamate hypofunctional state along the visual pathway in the affected parts of the visual field. An effective strategy to remedy this loss of function might be to increase extracellular levels of d-serine and thereby boost synaptic NMDA receptor-mediated visual transmission and/or plasticity to compensate for the impairment. We tested this idea in brain slices of visual cortex exhibiting long-term potentiation, and in rodent models of visual dysfunction caused by retinal insults at a time when the injury had stabilized to look for neuroenhancement effects. An essential aspect of the in vivo studies involved adapting sweep VEP technology to conscious rats and rabbits and combining it with intracortical recording while the animals were actively attending to visual information. Using this technology allowed us to establish complete contrast sensitivity function curves. We found that systemic d-serine dose-dependently rescued the contrast sensitivity impairment in rats with blue light-induced visual dysfunction. In rabbits with inner retinal dysfunction, both systemic and intravitreal routes of d-serine provided a rescue of visual function. In sum, we show that co-agonist stimulation of the NMDA receptor via administration of exogenous d-serine might be an effective therapeutic strategy to enhance visual performance and compensate for the loss of vision resulting from retinal disease.

  9. Central neuropeptide Y receptors are involved in 3rd ventricular ghrelin induced alteration of colonic transit time in conscious fed rats

    Directory of Open Access Journals (Sweden)

    Ritter Michael

    2005-02-01

    Full Text Available Abstract Background Feeding related peptides have been shown to be additionally involved in the central autonomic control of gastrointestinal functions. Recent studies have shown that ghrelin, a stomach-derived orexigenic peptide, is involved in the autonomic regulation of GI function besides feeding behavior. Pharmacological evidence indicates that ghrelin effects on food intake are mediated by neuropeptide Y in the central nervous system. Methods In the present study we examine the role of ghrelin in the central autonomic control of GI motility using intracerobroventricular and IP microinjections in a freely moving conscious rat model. Further the hypothesis that a functional relationship between NPY and ghrelin within the CNS exists was addressed. Results ICV injections of ghrelin (0.03 nmol, 0.3 nmol and 3.0 nmol/5 μl and saline controls decreased the colonic transit time up to 43%. IP injections of ghrelin (0.3 nmol – 3.0 nmol kg-1 BW and saline controls decreased colonic transit time dose related. Central administration of the NPY1 receptor antagonist, BIBP-3226, prior to centrally or peripherally administration of ghrelin antagonized the ghrelin induced stimulation of colonic transit. On the contrary ICV-pretreatment with the NPY2 receptor antagonist, BIIE-0246, failed to modulate the ghrelin induced stimulation of colonic motility. Conclusion The results suggest that ghrelin acts in the central nervous system to modulate gastrointestinal motor function utilizing NPY1 receptor dependent mechanisms.

  10. [Effect of corticotropin releasing factor(CRF) on somatic pain sensitivity in conscious rats: involvement of CRF1 and CRF2 receptors].

    Science.gov (United States)

    Iarushkina, N I; Bagaeva, T R; Filaretova, L P

    2014-11-01

    Corticotropin-releasing factor (CRF) is involved in the regulation of pain sensitivity and can cause an analgesic effect in animals and humans. The aim of the study was to investigate the involvement of CRF1 and CRF2 receptors in CRF-induced analgesic effect (after intraperitoneal injection) on somatic pain sensitivity in conscious rats. Somatic pain sensitivity was tested by tail flick latency (tail flick test). The involvement of CRF1 and CRF2 receptors was studied by their selective antagonists NBI 27914 and astressin 2B, respectively. Systemic administration of CRF caused an increase in tail flick latency (analgesic effect). Pretreatment with NBI 27914 or astressin 2B eliminated CRF-induced analgesic effect. Besides, NBI 27914, but not astressin 2B, increased basal tail flick latency. The data obtained indicate that the analgesic effect can be mediated by both CRF1 and CRF2 receptors. CRF-1 receptor, in contrast to the CRF2 receptors, may be involved in the regulation of the basal level of pain sensitivity.

  11. Regional haemodynamic effects of mu-, delta-, and kappa-opioid agonists microinjected into the hypothalamic paraventricular nuclei of conscious, unrestrained rats.

    Science.gov (United States)

    Bachelard, H; Pître, M

    1995-06-01

    1. The cardiovascular effects of bilateral injection into the hypothalamic paraventricular nuclei of selective mu-, delta-, and kappa-opioid receptor agonists were investigated in conscious, unrestrained Wistar Kyoto rats, chronically instrumented with pulsed Doppler flow probes for measurement of regional haemodynamics. 2. The selective mu-agonist [D-Ala2,MePhe4,Gly5ol]enkephalin (DAMGO), injected bilaterally into the hypothalamic paraventricular nuclei (0.01-1.0 nmol), caused increases in blood pressure, tachycardias, vasoconstriction in renal and superior mesenteric vascular beds and substantial vasodilatation in the hindquarter vascular bed. 3. The administration of increasing doses (0.01-5.0 nmol) of the selective delta-agonist [D-Phe2,5]enkephalin (DPDPE) or the selective kappa-agonist, U50488H into the paraventricular nuclei (PVN) had no significant effect on blood pressure, heart rate, or regional haemodynamics. 4. Together, the present results are further evidence of a role for opioid peptides, especially acting at mu-receptors in the PVN, in the central regulation of the cardiovascular system, whereas a role for opioid peptides, acting at delta- and kappa-receptors in the PVN, seems less obvious from the present results.

  12. Role of CCK-A receptor in the regulation of pancreatic bicarbonate secretion in conscious rats: a study in naturally occurring CCK-A receptor gene knockout rats.

    Science.gov (United States)

    Miyasaka, K; Suzuki, S; Kanai, S; Masuda, M; Funakoshi, A

    1999-10-01

    Whether cholecystokinin (CCK) has a direct action on duct cells and the role of CCK-A receptor in bicarbonate secretion were examined by comparing the results obtained from OLETF (CCK-A receptor-deficient rats) and control (LETO) rats. Rats were prepared with cannulae for draining bile and pancreatic juice separately, with two duodenal cannulae and an external jugular vein cannula. The experiments were conducted without anesthesia. The responses of bicarbonate secretion to intravenous infusion of CCK, acetyl-beta-methylcholine (Ach), and 2-deoxy-D-glucose (2DG), and to intraduodenal infusion of HCl and a liquid meal were examined. To examine the synergistic effect between CCK and secretin, the effect of CCK during a background secretin infusion was examined in LETO rats. CCK did not stimulate bicarbonate secretion in either strain, nor in LETO rats with secretin infusion. When gastric acid secretion was prevented by administration of omeprazole, Ach did not increase bicarbonate secretion, but 2DG did in both strains. Intraduodenal infusion of HCI and a liquid meal significantly increased bicarbonate secretion in both strains; however, the responses were much less in OLETF than LETO rats. In conclusion, intravenous injection of CCK did not stimulate bicarbonate secretion, and the lack of CCK-A receptor decreased bicarbonate secretion in response to luminal stimulants.

  13. An Essay on Consciousness.

    Science.gov (United States)

    Webb, Wise B.

    1981-01-01

    Reviews the role of consciousness within the discipline of psychology (including psychology research and textbooks). Presents information on the nature of consciousness, problems with consciousness, the mind/ matter controversy, and the state of the art of consciousness within psychology today. Concludes that there is a shift in psychology toward…

  14. Electroacupuncture Pretreatment at GB20 Exerts Antinociceptive Effects via Peripheral and Central Serotonin Mechanism in Conscious Migraine Rats

    Directory of Open Access Journals (Sweden)

    Lu Liu

    2016-01-01

    Full Text Available Background. While electroacupuncture (EA pretreatment in migraine has been found to attenuate pain and frequencies of attacks, the underlying mechanism of its antinociceptive effect remains poorly understood. Emerging evidence suggests that the serotonin system may be involved in migraine pathophysiology. Method. Forty male Sprague-Dawley rats were randomly assigned to Control, Model, EA, and sham acupuncture (SA groups. HomeCageScan was used to measure the effects on spontaneous nociceptive behaviors. Radioimmunoassay and high-performance liquid chromatography were used to evaluate the expression of 5-hydroxytryptamine (HT in the plasma and three-key structure of the descending pain modulatory system. Results. Our study showed that EA pretreatment could produce a significant reduction in resting, freezing, and grooming behavior and a significant increase in exploration behavior. Furthermore, we found that the level of 5-HT in plasma was significantly increased, and it was significantly decreased in the descending pain modulatory system in Model group. The aforementioned results were significantly reversed in EA group; that is, the level of 5-HT was increased in the rostroventromedial medulla (RVM and trigeminal nucleus caudalis (TNC region and decreased in the plasma. Conclusion. EA pretreatment exerts antinociceptive effects in a rat model of recurrent migraine, possibly via modulation of the serotonin system.

  15. Effects of the NMDA receptor antagonists on deltamethrin-induced striatal dopamine release in conscious unrestrained rats.

    Science.gov (United States)

    Morikawa, Takuya; Furuhama, Kazuhisa

    2009-08-01

    To better understand the neurotoxicity caused by the pyrethroid pesticide, we examined the effects of the N-methyl-D-aspartate (NMDA) receptor antagonists MK-801, a non-competitive cation channel blocker, and 2-amino-5-phosphonovaleric acid (APV), a competitive Na(+) channel blocker, on extracellular dopamine levels in male Sprague-Dawley rats receiving the type II pyrethroid deltamethrin using an in vivo microdialysis system. Deltamethrin (60 mg/kg, i.p.) evidently increased striatal dopamine levels with a peak time of 120 min, and the local infusion (i.c.) of either MK-801(650 muM) or APV (500 muM) completely blocked these actions. The fluctuation in the dopamine metabolite 3-MT also resembled that in dopamine. Our results suggest that dopamine-releasing neurons would be modulated via the NMDA receptor by the excitatory glutamatergic neurons after deltamethrin treatment.

  16. Hyperinsulinemic rats are normotensive but sensitized to angiotensin II

    DEFF Research Database (Denmark)

    Johansson, Maria E; Andersson, Irene J; Alexanderson, Camilla;

    2008-01-01

    ), and acute ganglion blockade and air-jet stress to investigate possible control of BP by the sympathetic nervous system. In addition, we used myograph technique to study vascular function ex vivo. INS and INS-LOS developed euglycemic hyperinsulinemia. Insulin did not affect BP but increased HR (27 beats....../min on average). Ganglion blockade reduced mean arterial blood pressure (MAP) similarly in all groups. Air-jet stress did not increase sympathetic reactivity but rather revealed possible blunting of the stress response in hyperinsulinemia. Chronic losartan markedly reduced 24-hour-MAP in the INS-LOS group (-38...

  17. Kinetics of eicosapentaenoic acid in brain, heart and liver of conscious rats fed a high n-3 PUFA containing diet.

    Science.gov (United States)

    Igarashi, Miki; Chang, Lisa; Ma, Kaizong; Rapoport, Stanley I

    2013-01-01

    Eicosapentaenoic acid (EPA, 20:5n-3), a precursor of docosahexaenoic acid (DHA), may benefit cardiovascular and brain health. Quantifying EPA's in vivo kinetics might elucidate these effects. [1-(14)C]EPA was infused i.v. for 5min in unanesthetized male rats fed a standard EPA-DHA diet. Plasma and microwaved tissue were analyzed. Kinetic parameters were calculated using our compartmental model. At 5min, 31-48% of labeled EPA in brain and heart was oxidized, 7% in liver. EPA incorporation rates from brain and liver precursor EPA-CoA pools into lipids, mainly phospholipids, were 36 and 2529nmol/s/g×10(-4), insignificant for heart. Deacylation-reacylation half-lives were 22h and 38-128min. Conversion rates to DHA equaled 0.65 and 25.1nmol/s/g×10(-4), respectively. The low brain concentration and incorporation rate and high oxidation of EPA suggest that, if EPA has a beneficial effect in brain, it might result from its suppression of peripheral inflammation and hepatic conversion to bioactive DHA.

  18. Somatic pain sensitivity during formation and healing of acetic acid-induced gastric ulcers in conscious rats.

    Science.gov (United States)

    Yarushkina, Natalya; Bogdanov, Anatoly; Filaretova, Ludmila

    2006-06-30

    A classical feature of visceral pain is its referring to somatic locations. Gastric ulcer is a source of visceral pain. In the present study we investigated whether gastric ulcers may trigger the changes in somatic nociception. For this aim somatic pain sensitivity was estimated under conditions of gastric ulcer development and healing. Gastric ulcers were induced by luminal application of 60% acetic acid under surgical conditions. Control rats were subjected to the same surgical procedure, but with the application of saline instead of the acid. Somatic pain sensitivity (tail flick latency), plasma corticosterone level, adrenal and thymus weight were investigated under conditions of the formation and the healing of gastric ulcers. The application of the acid resulted in the formation of kissing gastric ulcers, the increase of somatic pain sensitivity (the decrease of tail flick latency) as well as the appearance of typical signs of chronic stress: long-lasting increase of plasma corticosterone level, adrenal gland hypertrophy and thymus gland involution. Natural healing of gastric ulcers was accompanied by restoration of pain sensitivity as well as attenuation of the signs of chronic stress. Delay of ulcer healing by the daily indomethacin administration (2 mg/kg, s.c.) prevented the restoration of somatic pain sensitivity. The results suggest that chronic gastric ulcers may trigger somatic hypersensitivity.

  19. Microarray analysis of gene expression after electrical stimulation of the dura mater surrounding the superior sagittal sinus in conscious adult rats

    Institute of Scientific and Technical Information of China (English)

    Jiang Lei; Dong Zhao; Li Fengpeng; Liu Ruozhuo; Qiu Enchao; Wang Xiaolin; Yu Shengyuan

    2014-01-01

    Background The molecular and cellular origins of migraine headache are among the most complex problems in contemporary neurology.Up to now the pathogenesis of migraine still remains unclearly defined.The objective of this study was to explore new factors that may be related to the mechanism of migraine.Methods The present study performed a comprehensive analysis of gene expression in the trigeminal nucleus caudalis induced by electrical stimulation of dura mater surrounding the superior sagittal sinus in conscious rats using microarray analysis followed by quantitative real-time reverse-transcribed polymerase chain reaction (qRT-PCR) verification.Student's two sample t-test was employed when two groups were compared.A P value <0.05 was considered to be statistically significant.Results Comparing the placebo and the electrical stimulation groups,40 genes were determined to be significantly differentially expressed.These significantly differentially expressed genes were involved in many pathways,including transporter activity,tryptophan metabolism,G protein signaling,kinase activity,actin binding,signal transducer activity,anion transport,protein folding,enzyme inhibitor activity,coenzyme metabolism,binding,ion transport,cell adhesion,metal ion transport,oxidoreductase activity,mitochondrion function,and others.Most of the genes were involved in more than 2 pathways.Of particular interest is the up-regulation of Phactr3 and Akap5 and the down-regulation of Kdr.Conclusion These findings may provide important clues for a better understanding of the molecular mechanism of migraine.

  20. Mechanisms of the regional hemodynamic effects of a mu-opioid receptor agonist microinjected into the hypothalamic paraventricular nuclei of conscious unrestrained rats.

    Science.gov (United States)

    Bachelard, H; Pître, M; Lessard, A

    1997-01-01

    The present study was undertaken to characterize the mechanisms of the hemodynamic responses to microinjection of the selective mu-opioid receptor agonist [D-Ala2,MePhe4,Gly5-ol]enkephalin (DAMGO) into the paraventricular nucleus of the hypothalamus, in conscious rats chronically instrumented with pulsed Doppler flow probes. We found that i.v. pretreatment with phentolamine had no effect on the tachycardia elicited by DAMGO (1 nmol); however, the pressor response was reversed to a state of hypotension, the renal and superior mesenteric vasoconstrictions were attenuated and the hindquarter vasodilation was potentiated. In the presence of propranolol, the pressor response and renal vasoconstriction were unchanged, whereas the superior mesenteric vasoconstriction was reduced and the hindquarter vasodilation was abolished. Moreover, in those animals we observed bradycardia followed by tachycardia. Combined i.v. pretreatment with phentolamine and propranolol abolished the pressor and heart rate responses to DAMGO but had no effect on the renal and superior mesenteric vasoconstrictions, although the hindquarter vasodilation was reduced. Intravenous pretreatment with a vasopressin V1 receptor antagonist or captopril had no effect on the cardiovascular responses to DAMGO. Together, these results indicate that the hypertension observed after injection of DAMGO into the paraventricular nucleus of the hypothalamus was secondary to alpha adrenoceptor-mediated vasoconstrictions in renal and superior mesenteric vascular beds and to beta adrenoceptor-mediated vasodilation in the hindquarter vascular bed, whereas the involvement of circulating vasopressin or angiotensin seems less obvious from the present findings. However, we cannot exclude the possibility that nonadrenergic, nonvasopressinergic and nonangiotensinergic vasoconstrictor mechanisms were acting in the renal and superior mesenteric vascular beds.

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

    Science.gov (United States)

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

    1996-01-01

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

  2. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  3. Neural correlates of consciousness

    African Journals Online (AJOL)

    consciousness depends on the formation of complex arrangements which ... as well as the involvement of memory in consciousness. 40 Hz synchronized .... the cortex, thalamus, hippocampus and amygdala.1 Spiking activity in cholinergic ...

  4. Attention and Olfactory Consciousness

    OpenAIRE

    Andreas eKeller

    2011-01-01

    Understanding the relation between attention and consciousness is an important part of our understanding of consciousness. Attention, unlike consciousness, can be systematically manipulated in psychophysical experiments and a law-like relation between attention and consciousness is waiting to be discovered. Most attempts to discover the nature of this relation are focused on a special type of attention: spatial visual attention. In this review I want to introduce another type of attention to ...

  5. [Altered states of consciousness].

    Science.gov (United States)

    Gora, E P

    2005-01-01

    The review of modern ideas concerning the altered states of consciousness is presented in this article. Various methods of entry into the altered states of consciousness are looked over. It is shown that the altered states of consciousness are insufficiently known, but important aspects of human being existence. The role of investigation of the altered states of consciousness for the creation of integrative scientific conception base is discussed.

  6. Consciousness, brain, neuroplasticity

    OpenAIRE

    Askenasy, Jean; Lehmann, Joseph

    2013-01-01

    Subjectivity, intentionality, self-awareness and will are major components of consciousness in human beings. Changes in consciousness and its content following different brain processes and malfunction have long been studied. Cognitive sciences assume that brain activities have an infrastructure, but there is also evidence that consciousness itself may change this infrastructure. The two-way influence between brain and consciousness has been at the center of philosophy and less so, of science...

  7. Nonneurocognitive Extended Consciousness

    Science.gov (United States)

    Wojcik, Kevin; Chemero, Anthony

    2012-01-01

    One of the attributes necessary for Watson to be considered human is that it must be conscious. From Rachlin's (2012) point of view, that of teleological behaviorism, consciousness refers to the organization of behavioral complexity in which overt behavior is distributed widely over time. Consciousness is something that humans do, or achieve, in…

  8. Nonneurocognitive Extended Consciousness

    Science.gov (United States)

    Wojcik, Kevin; Chemero, Anthony

    2012-01-01

    One of the attributes necessary for Watson to be considered human is that it must be conscious. From Rachlin's (2012) point of view, that of teleological behaviorism, consciousness refers to the organization of behavioral complexity in which overt behavior is distributed widely over time. Consciousness is something that humans do, or achieve, in…

  9. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    changes or to abandon the strong identity thesis altogether. Were one to pursue a theory according to which consciousness is not an epiphenomenon to brain processes, consciousness may in fact affect its own neural basis. The neural correlate of consciousness is often seen as a stable structure, that is...

  10. Prostaglandins, catecholamines, renin and aldosterone during hypertensive and normotensive pregnancy.

    Science.gov (United States)

    Pedersen, E B; Christensen, N J; Christensen, P; Johannesen, P; Kornerup, H J; Kristensen, S; Lauritsen, J G; Leyssac, P P; Rasmussen, A B; Wohlert, M

    1982-01-01

    Urinary excretion of prostaglandin E2 (PGE2) and F2 alpha (PGF2 alpha), plasma concentrations of renin (PRC), aldosterone (PAC), noradrenaline (PNA) and adrenaline (PA) were determined in the third trimester of pregnancy, 5 days and 3 months after delivery in preeclampsia and normotensive pregnant and non-pregnant control subjects. PGE2 was higher in pregnant control subjects than in non-pregnant subjects, but reduced to non-pregnant level in preeclampsia. PGF2 alpha was the same in preeclampsia and normotensive pregnancy but higher than in the non-pregnant group. PRC and PAC were increased during pregnancy, but considerably lesser in preeclampsia than during normotensive pregnancy. PNA and PA were the same in all three groups. All parameters were normal 3 months after delivery. There were no correlations between any of the hormones and blood pressure in any of the groups. PGE2 was positively correlated to PRC. The lack of renal PGE2 in preeclampsia might be responsible for the decrease in renal blood flow and sodium excretion, and the changes in PRC and PAC are supposed to be secondary to changes in PGE2. It is hypothesised that preeclampsia is a state of prostaglandin deficiency.

  11. A case of normotensive pheochromocytoma with management dilemma

    Directory of Open Access Journals (Sweden)

    Mukut Roy

    2012-01-01

    Full Text Available Introduction: We report an unusual case of normotensive pheochromocytoma detected incidentally, presenting a pre-operative management problem. Case Note: A 40-year-old lady with vague abdominal symptoms was initially discovered with a left adrenal incidentaloma by ultrasound abdomen, which was also revealed in computed tomography (CT. After exclusion of all the causes with possible necessary investigations, pheochromocytoma was confirmed with elevated 24 hour urinary metanephrine and normetanephrine. Her blood pressure was in low to normotensive range all throughout. She was attempted to be prepared with combined alpha and beta blockade but could not tolerate this regimen due to symptomatic hypotension. Subsequently, surgical preparation was planned cautiously with alpha-adenergic blockade only. With intensive monitoring, she underwent uneventful left adrenalectomy, and surgical pathology was consistent with pheochromocytoma. Conclusion: This case illustrates an unusual presentation of normotensive pheochromocytoma as adrenal incidentaloma. Pre-operative preparation in these patients can be achieved with alpha-adrenergic blockade, adequate hydration, and liberal salt intake.

  12. Release of regulatory gut peptides somatostatin, neurotensin and vasoactive intestinal peptide by acid and hyperosmolal solutions in the intestine in conscious rats.

    Science.gov (United States)

    Rudholm, T; Wallin, B; Theodorsson, E; Näslund, E; Hellström, P M

    2009-01-08

    The impact of exposure of the intestinal mucosa to acid and hyperosmolal solutions on the release of the inhibitory gut peptides somatostatin (SOM), neurotensin (NT) and vasoactive intestinal peptide (VIP) was studied in conscious rats during pentagastrin-stimulated gastric acid secretion. The animals were equipped with a chronic gastric fistula to measure acid secretion and a jejunal Thiry-Vella loop for intestinal challenge with saline, hydrochloric acid (HCl, 200 mmol L(-1)) or hyperosmolal polyethylene glycol (PEG, 1200 mOsm kg(-1)). Gut peptide concentrations were measured in intestinal perfusates, and in plasma samples collected during stimulated acid secretion, and at the end of experiments with luminal challenge of the loops. After pentagastrin-stimulation acid secretion was dose-dependently inhibited by intravenous administration of the gastrin receptor antagonist gastrazole, as well as ranitidine and esomeprazole by maximally 73+/-10%; 95+/-3%; 90+/-10%, respectively. Acid perfusion of the Thiry-Vella loop caused a prominent release of SOM both to the lumen (from 7.2+/-5.0 to 1279+/-580 pmol L(-1)) and to the circulation (from 18+/-5.2 to 51+/-9.0 pmol L(-1)) simultaneously with an inhibition of gastric acid secretion. The release of NT and VIP was not affected to the same extent. PEG perfusion of the loop caused a release of SOM as well as NT and VIP, but less. Simultaneously acid secretion was slightly decreased. In conclusion, intestinal perfusion with acid or hyperosmolal solutions mainly releases SOM, which seems to exert a major inhibitory action in the gut, as shown by inhibition of acid secretion. The other peptides NT and VIP also participate in this action but to a much lesser degree. The operative pathways of these gut peptides hence involve both endocrine (SOM) and paracrine actions (SOM, NT, VIP) in order to exert inhibitory functions on the stomach. The inhibitory action of gastrazole, was in a similar range as that of SOM implying that

  13. Acute loss of consciousness.

    Science.gov (United States)

    Tristán, Bekinschtein; Gleichgerrcht, Ezequiel; Manes, Facundo

    2015-01-01

    Acute loss of consciousness poses a fascinating scenario for theoretical and clinical research. This chapter introduces a simple yet powerful framework to investigate altered states of consciousness. We then explore the different disorders of consciousness that result from acute brain injury, and techniques used in the acute phase to predict clinical outcome in different patient populations in light of models of acute loss of consciousness. We further delve into post-traumatic amnesia as a model for predicting cognitive sequels following acute loss of consciousness. We approach the study of acute loss of consciousness from a theoretical and clinical perspective to conclude that clinicians in acute care centers must incorporate new measurements and techniques besides the classic coma scales in order to assess their patients with loss of consciousness.

  14. Consciousness and the self.

    Science.gov (United States)

    Di Francesco, Michele

    2008-01-01

    In this paper I argue that, even though there is no doubt that to understand consciousness we have to understand the brain, the idea that a complete understanding of the essence of the phenomenon of human consciousness might derive from neuroscience alone is more disputable. Major progress in our understanding of the phenomenon of consciousness can certainly derive from neuroscience, but, as far as human consciousness is concerned, the thesis that since consciousness starts as a biological reality the proper locus of its analysis and explanation lies in neuroscience encounters serious difficulties. In particular, any theory of human consciousness that entails an explanation of the genesis and the nature of the subject of experience would require reference to social and cultural phenomena as well as to biological phenomena: the science of human consciousness, then, cannot avoid being intrinsically pluralistic in character.

  15. Perfil nutricional e cardiovascular de ratos normotensos e hipertensos sob dieta hiperlipídica Perfil nutricional y cardiovascular de ratas normotensas e hipertensos bajo dieta hiperlipídica Nutritional and cardiovascular profiles of normotensive and hypertensive rats kept on a high fat diet

    Directory of Open Access Journals (Sweden)

    Silvio A. Oliveira Júnior

    2009-11-01

    contempló la presión arterial sistólica (PAS, evaluación cardiopulmonar anatómica, ecocardiograma e histología cardiaca. RESULTADOS: Las SHRs presentaron menor PC, adiposidad, glucosa, colesterol, triacilglicerol, leptina e insulina, cuando comparadas a las WKYs. En las SHR, la ingestión calórica aumentó con la DH. Sin embargo en las WKYs, la DH elevó la eficiencia energética, la adiposidad y la leptina y reduzco la glucemia. En la evaluación cardiovascular, las SHR presentaron mayor PAS, humedad pulmonar, hipertrofia y fibrosis intersticial miocárdica en cuanto a las WKYs (pBACKGROUND: Although a high fat diet (HFD promotes nutritional and heart disorders, few studies have assessed its influence in normotensive Wistar-Kyoto rats (WKY and spontaneously hypertensive rats (SHR. OBJECTIVE: To evaluate and compare the nutritional and cardiovascular profiles of WKY and SHR on a high fat diet. METHODS: 20 WKY and 20 SHR were divided into four groups: Control-WKY (C-WKY, HFD-WKY, Control-SHR (C-SHR and HFD-SHR. The C and HFD groups received, respectively, a normocaloric diet and a HFD for 20 weeks. The following features were evaluated: body weight (BW, adiposity, blood glucose, serum lipids, with measurements of total cholesterol and triacylglycerol levels, insulin and leptin. The cardiovascular study included the systolic blood pressure (SBP, a cardiopulmonary anatomical evaluation, an echocardiography and heart histology. RESULTS: The SHR had BW, adiposity, glucose, cholesterol, triacylglycerol, leptin and insulin levels lower than the WKY. In SHR, the caloric intake increased with HFD. In WKY, the HFD increased energy efficiency, adiposity and blood leptin, and reduced glucose. In the cardiovascular assessment, the SHR had SBP, pulmonary moisture, myocardial hypertrophy and interstitial fibrosis higher than the WKY (p <0.01; the cardiac function was similar in both strains. The HFD reduced the ventricular systolic diameter in the WKY and increased the mitral E

  16. Attention and Olfactory Consciousness

    Directory of Open Access Journals (Sweden)

    Andreas eKeller

    2011-12-01

    Full Text Available Understanding the relation between attention and consciousness is an important part of our understanding of consciousness. Attention, unlike consciousness, can be systematically manipulated in psychophysical experiments and a law-like relation between attention and consciousness is waiting to be discovered. Most attempts to discover the nature of this relation are focused on a special type of attention: spatial visual attention. In this review I want to introduce another type of attention to the discussion: attention to the olfactory modality. I will first clarify the position of attention to smells in a general taxonomy of attention. I will then review the mechanisms and neuroanatomy of attention and consciousness in the olfactory system before using the newly introduced system to provide evidence that attention is necessary for consciousness.

  17. The Science of Consciousness

    CERN Document Server

    CERN. Geneva

    2015-01-01

    We not only act in the world but we consciously perceive it. The interactions of myriad of neuronal and sub-neuronal processes that are responsible for visual behaviors also give rise to the daily movie screened for our benefit in the privacy of our own skull. I will discuss the empirical progress that has been achieved over the past several decades in characterizing the behavioral and the neuronal correlates of consciousness in human and non-human animals and in dissociating selective visual attention from visual consciousness. I will introduce Tononi’s integrated Information Theory (IIT) that explains in a principled manner which physical systems are capable of conscious, subjective experience. The theory explains many empirical facts about consciousness and its pathologies in humans. It can also be extrapolated to more difficult cases, such as fetuses, mice, or bees. The theory predicts that many, seemingly complex, systems are not conscious, in particular digital computers running software, even if thes...

  18. Neural correlates of consciousness.

    Science.gov (United States)

    Negrao, B L; Viljoen, M

    2009-11-01

    A basic understanding of consciousness and its neural correlates is of major importance for all clinicians, especially those involved with patients with altered states of consciousness. In this paper it is shown that consciousness is dependent on the brainstem and thalamus for arousal; that basic cognition is supported by recurrent electrical activity between the cortex and the thalamus at gamma band frequencies; aand that some kind of working memory must, at least fleetingly, be present for awareness to occur. The problem of cognitive binding and the role of attention are briefly addressed and it shown that consciousness depends on a multitude of subconscious processes. Although these processes do not represent consciousness, consciousness cannot exist without them.

  19. Consciousness: a neurological perspective.

    Science.gov (United States)

    Cavanna, Andrea E; Shah, Sachin; Eddy, Clare M; Williams, Adrian; Rickards, Hugh

    2011-01-01

    Consciousness is a state so essentially entwined with human experience, yet so difficult to conceptually define and measure. In this article, we explore how a bidimensional model of consciousness involving both level of arousal and subjective awareness of the contents of consciousness can be used to differentiate a range of healthy and altered conscious states. These include the different sleep stages of healthy individuals and the altered states of consciousness associated with neurological conditions such as epilepsy, vegetative state and coma. In particular, we discuss how arousal and awareness are positively correlated in normal physiological states with the exception of REM sleep, while a disturbance in this relationship is characteristic of vegetative state, minimally conscious state, complex partial seizures and sleepwalking.

  20. Consciousness: A Neurological Perspective

    Directory of Open Access Journals (Sweden)

    Andrea E. Cavanna

    2011-01-01

    Full Text Available Consciousness is a state so essentially entwined with human experience, yet so difficult to conceptually define and measure. In this article, we explore how a bidimensional model of consciousness involving both level of arousal and subjective awareness of the contents of consciousness can be used to differentiate a range of healthy and altered conscious states. These include the different sleep stages of healthy individuals and the altered states of consciousness associated with neurological conditions such as epilepsy, vegetative state and coma. In particular, we discuss how arousal and awareness are positively correlated in normal physiological states with the exception of REM sleep, while a disturbance in this relationship is characteristic of vegetative state, minimally conscious state, complex partial seizures and sleepwalking.

  1. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    In contemporary consciousness studies the phenomenon of neural plasticity has received little attention despite the fact that neural plasticity is of still increased interest in neuroscience. We will, however, argue that neural plasticity could be of great importance to consciousness studies....... If consciousness is related to neural processes it seems, at least prima facie, that the ability of the neural structures to change should be reflected in a theory of this relationship "Neural plasticity" refers to the fact that the brain can change due to its own activity. The brain is not static but rather...... the relation between consciousness and brain functions. If consciousness is connected to specific brain structures (as a function or in identity) what happens to consciousness when those specific underlying structures change? It is therefore possible that the understanding and theories of neural plasticity can...

  2. 清醒大鼠动脉压力感受性反射-血压控制的测定%Determination of arterial baroreflex-blood pressure control in conscious rats

    Institute of Scientific and Technical Information of China (English)

    苏定冯; 陈力; 孔宪波; 程勇

    2002-01-01

    目的:研究清醒大鼠动脉压力感受性反射(ABR)-血压控制(ABR-BP)的测定.方法:用计算机化清醒自由活动大鼠血压连续监测技术,记录动物的血压.ABR-BP测定的原理是比较阻断ABR前后机体对血管活性物质反应的差异.结果:(1)用血管紧张素-Ⅱ测得的ABR-BP值与用新福林测得的ABR-BP值密切相关,在一定范围内药物的剂量不影响结果.(2)ABR-BP与ABR-心动间期控制(ABR-HP)显著相关.(3)麻醉抑制ABR-BP,ABR-BP本身存在昼夜节律性变化.(4)血压波动性与ABR-BP相关,而与ABR-HP不相关.(5)高血压时ABR-BP受损.结论:本项工作使ABR-BP的测定成为可能.ABR-BP在维持血压的稳定性中起重要作用,在高血压时其功能受损.%AIM:To study the determination of arterial baroreflexblood pressure control (ABR-BP) in conscious rats.METHODS:Blood pressure was continuously recorded with a computerized system in conscious freely moving rats.The principle of ABR-BP measurement is to compare the pressor response to a vasoactive drug (angiotensin Ⅱ ) before and after the interruption of this reflex.RESULTS:(1) ABR-BP values revealed by angiotensin Ⅱ were closely correlated with those by phenylephrine.Doses of angiotensin Ⅱ did not influence the results within certain range.(2) ABR-BP was well correlated with arterial baroreflex-heart period control (ABR-HP).(3) Anesthesia inhibited ABR-BP.There existed a circadian variation of ABR-BP in WKY rats.(4) Blood pressure variability was closely related to ABR-BP,but not to ABR-HP.(5) ABR-BP was impaired in hypertensive rots.CONCLUSION:ABRBP is an important parameter to reflect the function of ABR.The present work makes it possible to determine ABR-BP in conscious rats.ABR-BP plays an important role in maintaining blood pressure stability and it is impaired in hypertension.

  3. The sense of consciousness.

    Science.gov (United States)

    Tannenbaum, A S

    2001-08-21

    I propose that consciousness might be understood as the property of a system that functions as a sense in the biological meaning of that term. The theory assumes that, as a complex system, the sense of consciousness is not a fixed structure but implies structure with variations and that it evolved, as many new functions do, through the integration of simpler systems. The recognized exteroceptive and enteroceptive senses provide information about the organism's environment and about the organism itself that are important to adaptation. The sense of consciousness provides information about the brain and thus about the organism and its environment. It senses other senses and processes in the brain, selecting and relating components into a form that "makes sense"-where making sense is defined as being useful to the organism in its adaptation to the environment. The theory argues that this highly adaptive organizing function evolved with the growing complexity of the brain and that it might have helped resolve discrepancies created at earlier stages. Neural energies in the brain that are the input to the sense of consciousness, along with the processing subsystem of which they are a part, constitute the base of consciousness. Consciousness itself is an emergent effect of an organizing process achieved through the sense of consciousness. The sense of consciousness thus serves an organizing function although it is not the only means of organization in the brain. Its uniqueness lies in the character of the organization it creates with consciousness as a property of that organization. The paper relates the theory to several general conceptions-interactionism, epiphenomenalism and identity theory-and illustrates a number of testable hypotheses. Viewing consciousness as a property of a sense provides a degree of conceptual integration. Much of what we know about the evolution and role of the conventionally recognized senses should help us understand the evolution and role of

  4. Consciousness, brain, neuroplasticity.

    Science.gov (United States)

    Askenasy, Jean; Lehmann, Joseph

    2013-01-01

    Subjectivity, intentionality, self-awareness and will are major components of consciousness in human beings. Changes in consciousness and its content following different brain processes and malfunction have long been studied. Cognitive sciences assume that brain activities have an infrastructure, but there is also evidence that consciousness itself may change this infrastructure. The two-way influence between brain and consciousness has been at the center of philosophy and less so, of science. This so-called bottom-up and top-down interrelationship is controversial and is the subject of our article. We would like to ask: how does it happen that consciousness may provoke structural changes in the brain? The living brain means continuous changes at the synaptic level with every new experience, with every new process of learning, memorizing or mastering new and existing skills. Synapses are generated and dissolved, while others are preserved, in an ever-changing process of so-called neuroplasticity. Ongoing processes of synaptic reinforcements and decay occur during wakefulness when consciousness is present, but also during sleep when it is mostly absent. We suggest that consciousness influences brain neuroplasticity both during wakefulness as well as sleep in a top-down way. This means that consciousness really activates synaptic flow and changes brain structures and functional organization. The dynamic impact of consciousness on brain never stops despite the relative stationary structure of the brain. Such a process can be a target for medical intervention, e.g., by cognitive training.

  5. Consciousness, brain, neuroplasticity

    Directory of Open Access Journals (Sweden)

    Jean-Jacques Marcel Askenasy

    2013-07-01

    Full Text Available Subjectivity, intentionality, self-awareness and will are major components of consciousness in human beings. Changes in consciousness and its content following different brain processes and malfunction have long been studied. Cognitive sciences assume that brain activities have an infrastructure, but there is also evidence that consciousness itself may change this infrastructure. The two-way influence between brain and consciousness has been at the center of philosophy and less so, of science. This so-called bottom-up and top-down interrelationship is controversial and is the subject of our article. We would like to ask: how does it happen that consciousness may provoke structural changes in the brain?The living brain means continuous changes at the synaptic level with every new experience, with every new process of learning, memorizing or mastering new and existing skills. Synapses are generated and dissolved, while others are preserved, in an ever-changing process of so-called neuroplasticity. Ongoing processes of synaptic reinforcements and decay occur during wakefulness when consciousness is present, but also during sleep when it is mostly absent.We suggest that consciousness influences brain neuroplasticity both during wakefulness as well as sleep in a top-down way. This means that consciousness really activates synaptic flow and changes brain structures and functional organization. The dynamic impact of consciousness on brain never stops despite the relative stationary structure of the brain. Such a process can be a target for medical intervention e.g. by cognitive training.

  6. Ethnic differences in resistance artery contractility of normotensive pregnant women.

    Science.gov (United States)

    Brewster, L M; Taherzadeh, Z; Volger, S; Clark, J F; Rolf, T; Wolf, H; Vanbavel, E; van Montfrans, G A

    2010-08-01

    Black women are at a greater risk to develop hypertension during pregnancy, with a 4.5 times higher rate of fatal preeclampsia than white women. Therefore, it is important to identify factors that may affect this risk. Our group previously proposed that high activity of the central regulatory enzyme of energy metabolism, creatine kinase (CK), may increase ATP-buffering capacity and lead to enhanced vascular contractility and reduced nitric oxide bioavailability. Therefore, we assessed microvascular contractility characteristics in isolated resistance arteries from self-defined black and white normotensive pregnant women using a Mulvany-Halpern myograph. Additionally, morphology was assessed with electron microscopy. Resistance-sized arteries obtained from omentum donated during cesarean sections (11 black women and 20 white women, mean age: 34 yr) studied in series showed similar morphology but significantly greater maximum contractions to norepinephrine (10(-5) M) in blacks [14.0 mN (1.8 SE)] compared with whites [8.9 mN (1.4 SE), P = 0.02]. Furthermore, we found greater residual contractility after the specific CK inhibitor dinitrofluorobenzene (10(-6) M) in black women [55% (6 SE)] compared with white women [28% (4 SE), P = 0.001] and attenuated vasodilation after bradykinin (10(-7) M) in black women [103% (6 SE)] compared with white women [84% (5 SE), P = 0.023], whereas responses to sodium nitroprusside (10(-4) M) and amlodipine (10(-6) M) were similar. We conclude that compared with white women, normotensive pregnant black women display greater resistance artery contractility and evidence of higher vascular CK activity with attenuated nitric oxide synthesis. These findings in normotensives may imply that the black population is at risk for a further incline in pregnancy-related hypertensive disorders.

  7. Essential hypertensive controlled and normotensive patients. If there are differences?

    Directory of Open Access Journals (Sweden)

    V. V. Syvolap

    2016-10-01

    Full Text Available Ambulatory blood pressure monitoring (ABPM is a modern method of blood pressure (BP investigation recommended by international scientific associations for diagnostics of essential hypertension (EH. However, there are some methodological aspects which are not regulated. Particularly, ABPM parameters have not yet established for those patients in different age groups and pathologies. The aim of the study was to determine peculiarities of ABPM parameters in treated controlled hypertensive and normotensive patients. Materials and methods. 71 patients were included into the study and divided into two groups according to the level of 24-h systolic BP (SBP and 24-h diastolic BP (DBP. There were 50 controlled patients with EH in the first group and 21 normotensive individuals without EH in the second group. Results. In EH patients and normotensive individuals we had statistician difference of such parameters, like the hypertension time index (TI of day SBP parameters (20 (8–31 % vs. 8 (4–18 %; р=0.040; of the square index (SI of hypertension (24 (11–41 mm2/h vs. 8 (2–23 mm2/h; р=0.021; of the square index normalized (SIN of hypertension (1.4 (0.6–2.4 U vs. 0.4 (0.1–1.2 U; р=0.018, and the morning surge of SBP (45±14 mm Hg vs. 37±14 mm Hg; р=0.028, respectively. There is no different in other ABPM parameters. Conclusion. The present data shows that treated controlled hypertensive patients and individuals without EH have statistician difference only in daily SBP of hypertensive indexes (TI, SI, SIN and the morning surge of SBP. The other ABPM parameters, included new one, such as the arterial stiffness index, did not represent statistical difference between groups.

  8. Effects of fasting on Blood pressure in normotensive males

    Directory of Open Access Journals (Sweden)

    Fatima Samad

    2016-07-01

    Full Text Available Muslims all over the world fast in the holy month of Ramadan. Fasting means abstinence from drinking any liquids, eating, smoking and taking anything parenterally.  It is intermittent in nature from the start of dawn to end at dusk. Fasting has various physiological effects on different biological parameters of the human body. Previous studies that look at effect of Ramadan fasting on blood pressure have focused mainly on hypertensive patients and patients with already established heart disease.(1,2There is very limited data regarding the effect of fasting on the normal population. (3,4 A few previous studies have advocated a hypotensive role of fasting.(5 In our study published in Journal of Ayub Medical College Abbottabad (JAMC in 2015, “Effects of Ramadan Fasting on Blood pressure in normotensive males”, we investigated the effect of Ramadan fasting on blood pressure of normotensive men. We conducted a repeated measure observational study in Karachi, Pakistan on 70 individuals who were normotensive, non-smokers between the ages of 18–50 years. . Blood pressure, pulse, BMI of each participant was recorded one week before the start of Ramadan and in the first, second and third week of Ramadan. The results of our study show that intermittent fasting has a hypotensive effect in normotensive males as proven in animal models and certain human population. There was an average drop of 8/3 mmHg and while the results are significant, their clinical relevance needs to be analysed. Studies on animal models have suggested atrial natriuretic peptide, catecholamines, opiates and body mass index as possible reasons for the decrease in blood pressure due to fasting.(3, 6  Dewanti et al suggested that the cause of drop in blood pressure was the drop in BMI however in our study we found that a drop in BMI only occurred before Iftar towards the end of the fast. There was no significant drop in post-Iftar BMI although there was a significant drop in blood

  9. Aerobic exercise and intraocular pressure in normotensive and glaucoma patients

    Directory of Open Access Journals (Sweden)

    Chatzibalis Theodosios

    2009-08-01

    Full Text Available Abstract Background With the increasing number of people participating in physical aerobic exercise, jogging in particular, we considered that it would be worth knowing if there are should be limits to the exercise with regard to the intraocular pressure (IOP of the eyes. The purpose of this study is to check IOP in healthy and primary glaucoma patients after aerobic exercise. Methods 145 individuals were subdivided into seven groups: normotensives who exercised regularly (Group A; normotensives in whose right eye (RE timolol maleate 0.5% (Group B, latanoprost 0.005% (Group C, or brimonidine tartrate 0.2% (Group D was instilled; and primary glaucoma patients under monotherapy with β-blockers (Group E, prostaglandin analogues (Group F or combined antiglaucoma treatment (Group G instilled in both eyes. The IOP of both eyes was measured before and after exercise. Results A statistically significant decrease was found in IOP during jogging. The aerobic exercise reduces the IOP in those eyes where a b-blocker, a prostaglandin analogue or an α-agonist was previously instilled. The IOP is also decreased in glaucoma patients who are already under antiglaucoma treatment. Conclusion There is no ocular restriction for simple glaucoma patients in performing aerobic physical activity.

  10. Collective Consciousness and Idealist Philosophy

    OpenAIRE

    Randrup, Dr. Axel

    2005-01-01

    Abstract Descriptions of publications on collective consciousness, collective conscious experience, and idealist philosophy by Axel Randrup. The recognition of collective consciousness overcomes the problem of solipsism, which has been seen as an argument against idealist philosophy.

  11. The evolution of consciousness

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, H.P.

    1996-08-16

    It is argued that the principles of classical physics are inimical to the development of an adequate science of consciousness. The problem is that insofar as the classical principles are valid consciousness can have no effect on the behavior, and hence on the survival prospects, of the organisms in which it inheres. Thus within the classical framework it is not possible to explain in natural terms the development of consciousness to the high-level form found in human beings. In quantum theory, on the other hand, consciousness can be dynamically efficacious: quantum theory does allow consciousness to influence behavior, and thence to evolve in accordance with the principles of natural selection. However, this evolutionary requirement places important constraints upon the details of the formulation of the quantum dynamical principles.

  12. Neural Darwinism and consciousness.

    Science.gov (United States)

    Seth, Anil K; Baars, Bernard J

    2005-03-01

    Neural Darwinism (ND) is a large scale selectionist theory of brain development and function that has been hypothesized to relate to consciousness. According to ND, consciousness is entailed by reentrant interactions among neuronal populations in the thalamocortical system (the 'dynamic core'). These interactions, which permit high-order discriminations among possible core states, confer selective advantages on organisms possessing them by linking current perceptual events to a past history of value-dependent learning. Here, we assess the consistency of ND with 16 widely recognized properties of consciousness, both physiological (for example, consciousness is associated with widespread, relatively fast, low amplitude interactions in the thalamocortical system), and phenomenal (for example, consciousness involves the existence of a private flow of events available only to the experiencing subject). While no theory accounts fully for all of these properties at present, we find that ND and its recent extensions fare well.

  13. Consciousness and psychotherapy.

    Science.gov (United States)

    Ryle, A

    1994-06-01

    The origins and resistance to change of neurotic procedures are considered with particular reference to the nature and role of consciousness. It is argued that the traditional opposition between conscious and unconscious systems provides an unsatisfactory model. The crucial role of language in the formation of human self-consciousness is emphasized. The restricted procedural repertoire of neurotic subjects, and their deficient self-consciousness, can be attributed to a number of factors. It is argued that the main use of consciousness in therapy should be to heighten the patient's awareness of his or her damaging or restricting procedural repertoire through the process of reformulation, which allows recognition, and in due course revision to be achieved.

  14. Inner Consciousness Tindakan Nabi

    Directory of Open Access Journals (Sweden)

    Moh. Helmi Umam

    2015-09-01

    Full Text Available The article is written to examine deeds and actions of the Prophet Muhammad (peace be upon him within inner consciousness analysis of Husserl’s phenomenology. The article is formulated to explore the significance of phenomenology of religious study, Prophet’s deeds as well as his inner consciousness, and inner consciousness analysis of Prophet’s deeds. This article is written using phenomenological method, i.e. a comprehensive interpretation about the source of information or object’s phenomenon as long as it can be traced. Inner consciousness of Prophet’s actions sees that his deeds in deciding important religious pronouncements were results of long-term memory based on divine and social argumentations, which have came into Prophet’s consciousness as a human.

  15. Nociceptive behaviors were induced by electrical stimulation of the dura mater surrounding the superior sagittal sinus in conscious adult rats and reduced by morphine and rizatriptan benzoate.

    Science.gov (United States)

    Dong, Zhao; Jiang, Lei; Wang, Xiaohui; Wang, Xiaolin; Yu, Shengyuan

    2011-01-12

    The trigeminovascular nociception induced by electrical stimulation of the dura mater surrounding the superior sagittal sinus in anesthetized animals has been widely used as a model for investigation of the pathophysiology of vascular headache such as migraine. However, little is known whether pain behaviors can be induced using this model in conscious animals. Thus, to establish a new model of trigeminovascular nociception in conscious animals and to examine the effects of morphine and rizatriptan benzoate on nociceptive behaviors in this new model, we electrically stimulated the dura mater surrounding the superior sagittal sinus. We found that grooming and head-flick activities were altered partially in a frequency-dependent way and that frequencies ranging from 10 to 20 Hz more easily provoked these behaviors. Moreover, we also demonstrated that these behaviors were reduced by morphine and rizatriptan benzoate. Thus, this new model will provide a useful and appropriate tool to directly assess changes in the intensity of pain for further investigation of pathophysiological mechanisms of migraine in conscious animals.

  16. Characteristic of Ambulatory Blood Pressure in Normotensive Subjects With Type 2 Diabetes Mellitus

    Institute of Scientific and Technical Information of China (English)

    Chen Xiaochao; Xu Mingtong; Kong Minyi; Xue Shengneng

    2005-01-01

    Objectives To observe the characteristic of ambulatory blood pressure monitoring in normotensive diabetic subjects with normoalbuminuria or microalbuminuria. Methods Fifty-two normotensive patients with type 2 diabetes received ambulatory blood pressure monitoring were divided into normoalbuminuric and microalbuminuric groups according to their albumin excretion rate, the other 28 normotensive subjects without diabetes were contributed as control group. Ambulatory blood pressure monitoring was performed on a working day and measurement of blood pressure circadian rhythm was analyzed. Results Normotensive microalbuminuric diabetic patients had higher night-time systolic blood pressure and more blood pressure burden than normotensive normoalbuminuric diabetic patients. Additionally, the microalbuminuric patients had a higher frequency of non-dippers than normoalbuminuric ones, although they were all normotensive. Compared to the normotensive non-diabetic control subjects, the nighttime systolic blood pressure and frequency of nondippers of the normoalbuminuric diabetic patients were significantly higher. Conclusions Intensive attention should be paid in control of blood pressure in diabetic patients to prevent and limit damage of target organ including kidney, even in those normotensive subjects.

  17. Hemodynamic Responses Associated with Post-exercise Hypotension in Normotensive Black Males.

    Science.gov (United States)

    Headley, Samuel A.; And Others

    The purpose of this study was to characterize the hemodynamic responses during recovery from moderate intensity exercise in young Black normotensive males. Nineteen normotensive men (age 24-26 years) walked continuously on a treadmill for 40 minutes at 50-60 percent heart rate reserve. Following exercise, blood pressure (by auscultation) and…

  18. The Labdane Ent-3-Acetoxy-Labda-8(17), 13-Dien-15-Oic Decreases Blood Pressure In Hypertensive Rats

    Science.gov (United States)

    Simplicio, Janaina A.; Simão, Marilia R.; Ambrosio, Sergio R.; Tirapelli, Carlos R.

    2016-01-01

    Background Labdane-type diterpenes induce lower blood pressure via relaxation of vascular smooth muscle; however, there are no studies describing the effects of labdanes in hypertensive rats. Objective The present study was designed to investigate the cardiovascular actions of the labdane-type diterpene ent-3-acetoxy-labda-8(17), 13-dien-15-oic acid (labda-15-oic acid) in two-kidney 1 clip (2K-1C) renal hypertension. Methods Vascular reactivity experiments were performed in aortic rings isolated from 2K-1C and normotensive (2K) male Wistar rats. Nitrate/nitrite (NOx) measurement was performed in aortas by colorimetric assay. Blood pressure measurements were performed in conscious rats. Results Labda-15-oic acid (0.1-300 µmol/l) and forskolin (0.1 nmol/l - 1 µmol/l) relaxed endothelium-intact and endothelium-denuded aortas from both 2K-1C and 2K rats. Labda-15-oic acid was more effective at inducing relaxation in endothelium-intact aortas from 2K pre-contracted with phenylephrine when compared to the endothelium-denuded ones. Forskolin was more potent than labda-15-oic acid at inducing vascular relaxation in arteries from both 2K and 2K-1C rats. Labda-15-oic acid-induced increase in NOx levels was lower in arteries from 2K-1C rats when compared to 2K rats. Intravenous administration of labda-15-oic acid (0.3-3 mg/kg) or forskolin (0.1-1 mg/kg) induced hypotension in conscious 2K-1C and 2K rats. Conclusion The present findings show that labda-15-oic acid induces vascular relaxation and hypotension in hypertensive rats. PMID:27096521

  19. The Labdane Ent-3-Acetoxy-Labda-8(17), 13-Dien-15-Oic Decreases Blood Pressure In Hypertensive Rats

    Energy Technology Data Exchange (ETDEWEB)

    Simplicio, Janaina A. [Programa de Pós-Graduação em Farmacologia - Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, SP (Brazil); Departamento de Enfermagem Psiquiátrica e Ciências Humanas - Laboratório de Farmacologia - Escola de Enfermagem de Ribeirão Preto (USP), Ribeirão Preto, SP (Brazil); Simão, Marilia R.; Ambrosio, Sergio R. [Núcleo de Pesquisa em Ciências e Tecnologia - Universidade de Franca (UNIFRAN), Franca, SP (Brazil); Tirapelli, Carlos R., E-mail: crtirapelli@eerp.usp.br [Departamento de Enfermagem Psiquiátrica e Ciências Humanas - Laboratório de Farmacologia - Escola de Enfermagem de Ribeirão Preto (USP), Ribeirão Preto, SP (Brazil)

    2016-06-15

    Labdane-type diterpenes induce lower blood pressure via relaxation of vascular smooth muscle; however, there are no studies describing the effects of labdanes in hypertensive rats. The present study was designed to investigate the cardiovascular actions of the labdane-type diterpene ent-3-acetoxy-labda-8(17), 13-dien-15-oic acid (labda-15-oic acid) in two-kidney 1 clip (2K-1C) renal hypertension. Vascular reactivity experiments were performed in aortic rings isolated from 2K-1C and normotensive (2K) male Wistar rats. Nitrate/nitrite (NOx) measurement was performed in aortas by colorimetric assay. Blood pressure measurements were performed in conscious rats. Labda-15-oic acid (0.1-300 µmol/l) and forskolin (0.1 nmol/l - 1 µmol/l) relaxed endothelium-intact and endothelium-denuded aortas from both 2K-1C and 2K rats. Labda-15-oic acid was more effective at inducing relaxation in endothelium-intact aortas from 2K pre-contracted with phenylephrine when compared to the endothelium-denuded ones. Forskolin was more potent than labda-15-oic acid at inducing vascular relaxation in arteries from both 2K and 2K-1C rats. Labda-15-oic acid-induced increase in NOx levels was lower in arteries from 2K-1C rats when compared to 2K rats. Intravenous administration of labda-15-oic acid (0.3-3 mg/kg) or forskolin (0.1-1 mg/kg) induced hypotension in conscious 2K-1C and 2K rats. The present findings show that labda-15-oic acid induces vascular relaxation and hypotension in hypertensive rats.

  20. Effects of short- and long-term dexamethasone treatment on growth and growth hormone (GH)-releasing hormone (GRH)-GH-insulin-like growth factor-I axis in conscious rats.

    Science.gov (United States)

    Ohyama, T; Sato, M; Niimi, M; Hizuka, N; Takahara, J

    1997-12-01

    Although the inhibitory effects of a chronic excess of glucocorticoids (GC) on body growth and GH secretion are well established, the mechanisms involved remain unclear. In this study, we examined the chronic effects of a high dose of dexamethasone (DEX) on spontaneous GH secretion and insulin-like growth factor (IGF)-I in conscious rats. The animals were given daily i.p. injections of DEX (200 microg/day) for either one or four weeks. Body growth assessed by tibia length and serum IGF-I levels was significantly inhibited 1 week after treatment. By contrast, spontaneous GH secretion was not altered 1 week after the treatment. Neither hypothalamic GRH and somtatostain mRNA levels nor GH responses to GRH from single somatotropes were affected 1 week after the treatment. Four weeks after DEX treatment, body growth of the rats was noticeably suppressed. Interestingly, spontaneous GH secretion, hypothalamic GRH mRNA levels and GH responses to GRH were all inhibited 4 weeks after treatment. Pituitary GRH receptor mRNA levels were not altered 1 week after treatment, but increased after 4 weeks. These results indicate that a high dose of DEX initially impairs IGF-I production and subsequently inhibits spontaneous GH secretion in rats. Inhibition of spontaneous GH secretion resulting from chronic GC excess is due, at least in part, to the impairment of hypothalamic GRH synthesis and pituitary GH responsiveness. An increase in the pituitary GRH receptor may be caused by decreased GRH secretion.

  1. Consciousness in dreams.

    Science.gov (United States)

    Kahn, David; Gover, Tzivia

    2010-01-01

    This chapter argues that dreaming is an important state of consciousness and that it has many features that complement consciousness in the wake state. The chapter discusses consciousness in dreams and how it comes about. It discusses the changes that occur in the neuromodulatory environment and in the neuronal connectivity of the brain as we fall asleep and begin our night journeys. Dreams evolve from internal sources though the dream may look different than any one of these since something entirely new may emerge through self-organizing processes. The chapter also explores characteristics of dreaming consciousness such as acceptance of implausibility and how that might lead to creative insight. Examples of studies, which have shown creativity in dream sleep, are provided to illustrate important characteristics of dreaming consciousness. The chapter also discusses the dream body and how it relates to our consciousness while dreaming. Differences and similarities between wake, lucid, non-lucid and day dreaming are explored and the chapter concludes with a discussion on what we can learn from each of these expressions of consciousness. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Consciousness during dreams.

    Science.gov (United States)

    Cicogna, P C; Bosinelli, M

    2001-03-01

    Two aspects of consciousness are first considered: consciousness as awareness (phenomenological meaning) and consciousness as strategic control (functional meaning). As to awareness, three types can be distinguished: first, awareness as the phenomenal experiences of objects and events; second, awareness as meta-awareness, i.e., the awareness of mental life itself; third, awareness as self-awareness, i.e., the awareness of being oneself. While phenomenal experience and self-awareness are usually present during dreaming (even if many modifications are possible), meta-awareness is usually absent (apart from some particular experiences of self-reflectiveness) with the major exception of lucid dreaming. Consciousness as strategic control may also be present in dreams. The functioning of consciousness is then analyzed, following a cognitive model of dream production. In such a model, the dream is supposed to be the product of the interaction of three components: (a) the bottom-up activation of mnemonic elements coming from LTM systems, (b) interpretative and elaborative top-down processes, and (c) monitoring of phenomenal experience. A feedback circulation is activated among the components, where the top-down interpretative organization and the conscious monitoring of the oneiric scene elicitates other mnemonic contents, according to the requirements of the dream plot. This dream productive activity is submitted to unconscious and conscious processes. Copyright 2001 Academic Press.

  3. Blood Pressure Interventions Affect Acute and Four-Week Diesel Exhaust Induced Pulmonary Injury in Healthy and Hypertensive Rats

    Science.gov (United States)

    Rationale: We recently showed that inhalation exposure of normotensive Wistar Kyoto (WKY) rats to whole diesel exhaust (DE) elicits changes in cardiac gene expression that broadly mimics expression in spontaneously hypertensive (SH) rats without DE. We hypothesized that pharmacol...

  4. Cardiac autonomic dysfunction in obese normotensive children and adolescents

    Directory of Open Access Journals (Sweden)

    Isabelle Magalhães G. Freitas

    2014-06-01

    Full Text Available OBJECTIVE:To test the hypothesis that obese normotensive children and adolescents present impaired cardiac autonomic control compared to non-obese normotensive ones.METHODS:For this cross-sectional study, 66 children and adolescents were divided into the following groups: Obese (n=31, 12±3 years old and Non-Obese (n=35, 13±3 years old. Obesity was defined as body mass index greater than the 95thpercentile for age and gender. Blood pressure was measured by oscillometric method after 15 minutes of rest in supine position. The heart rate was continuously registered during ten minutes in the supine position with spontaneous breathing. The cardiac autonomic control was assessed by heart rate variability, which was calculated from the five-minute minor variance of the signal. The derivations were the index that indicates the proportion of the number of times in which normal adjacent R-R intervals present differences >50 miliseconds (pNN50, for the time domain, and, for the spectral analysis, low (LF and high frequency (HF bands, besides the low and high frequencies ratio (LF/HF. The results were expressed as mean±standard deviation and compared by Student's t-test or Mann-Whitney's U-test.RESULTS: Systolic blood pressure (116±14 versus 114±13mmHg, p=0.693 and diastolic blood pressure (59±8 versus 60±11mmHg, p=0.458 were similar between the Obese and Non-Obese groups. The pNN50 index (29±21 versus 43±23, p=0.015 and HF band (54±20 versus 64±14 normalized units - n.u., p=0.023 were lower in the Obese Group. The LF band (46±20 versus 36±14 n.u., p=0.023 and LF/HF ratio (1.3±1.6 versus 0.7±0.4, p=0.044 were higher in Obese Group.CONCLUSIONS: Obese normotensive children and adolescents present impairment of cardiac autonomic control.

  5. From cholesterol to consciousness.

    Science.gov (United States)

    Torday, John S

    2017-08-19

    The nature of consciousness has been debated for centuries. It can be understood as part and parcel of the natural progression of life from unicellular to multicellular, calcium fluxes mediating communication within and between cells. Consciousness is the vertical integration of calcium fluxes, mediated by the Target of Rapamycin gene integrated with the cytoskeleton. The premise of this paper is that there is a fundamental physiologic integration of the organism with the environment that constitutes consciousness. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Urinary cortisol/cortisone ratios in hypertensive and normotensive cats.

    Science.gov (United States)

    Walker, David J; Elliott, Jonathan; Syme, Harriet M

    2009-06-01

    Hypertension is a common problem in older cats, particularly associated with chronic kidney disease (CKD). Reduced activity of 11beta-hydroxysteroid dehydrogenase type 2 predisposes to hypertension in human patients by allowing excessive stimulation of the mineralocorticoid receptor by cortisol. This study was designed to test the hypothesis that reduced conversion of cortisol to cortisone contributes to the development of systemic hypertension in some cats with CKD and idiopathic hypertension (iHT). The study included 60 client-owned cats: 21 clinically normal, 16 normotensive cats with CKD (NTCKD), 14 hypertensive cats with CKD (HTCKD) and nine iHTs. Urine cortisol and cortisone were extracted into dichloromethane and chloroform, respectively, prior to analysis by radioimmunoassay. Data are reported as median and range. The Kruskall-Wallis test was used to compare cortisol:cortisone ratios between groups with post-hoc testing using the Mann-Whitney U test. Wilcoxon signed-ranks test was used to compare results before and after treatment of hypertensive cats with amlodipine. The urinary cortisol:cortisone ratio was significantly higher in clinically normal cats (0.87; 0.46-1.39) when compared to NTCKD (0.60; 0.35-1.20; Pcortisone ratio was detected (P=0.327). Reduced urinary cortisol to cortisone conversion does not appear to be associated with systemic hypertension in cats. In fact, the cortisol to cortisone shuttle appears to be more effective in cats with CKD (hypertensive and normotensive) and iHT than clinically normal cats. The mechanism for this potentially adaptive response to kidney disease is not clear.

  7. Logical Evaluation of Consciousness: For Incorporating Consciousness into Machine Architecture

    OpenAIRE

    2010-01-01

    Machine Consciousness is the study of consciousness in a biological, philosophical, mathematical and physical perspective and designing a model that can fit into a programmable system architecture. Prime objective of the study is to make the system architecture behave consciously like a biological model does. Present work has developed a feasible definition of consciousness, that characterizes consciousness with four parameters i.e., parasitic, symbiotic, self referral and reproduction. Prese...

  8. Are We Explaining Consciousness Yet?

    Science.gov (United States)

    Dennett, Daniel

    2001-01-01

    Maintains that theorists are converging on a version of the global neuronal workspace model of consciousness, but that there are residual confusions to be dissolved. Asserts that global accessibility is not the "cause" of consciousness, it "is" consciousness. Argues that like fame, consciousness is not a momentary condition or…

  9. Evolution of consciousness.

    OpenAIRE

    Eccles, J C

    1992-01-01

    The hypothesis of the origin of consciousness is built upon the unique properties of the mammalian neocortex. The apical dendrites of the pyramidal cells bundle together as they ascend to lamina I to form neural receptor units of approximately 100 apical dendrites plus branches receiving hundreds of thousands of excitatory synapses, the collective assemblage being called a dendron. It is proposed that the whole world of consciousness, the mental world, is microgranular, with mental units call...

  10. Attention Networks and Consciousness

    Directory of Open Access Journals (Sweden)

    Michael ePosner

    2012-03-01

    Full Text Available The term consciousness is an important one in the vernacular of the western literature in many fields. It is no wonder that scientists have assumed that consciousness will be found as a component of the human brain and that we will come to understand its neural basis. However, there is rather little in common between consciousness as the neurologist would use it to diagnose the vegetative state, how the feminist would use it to support raising male consciousness of the economic plight of women and as the philosopher would use it when defining the really hard question of the subjective state of awareness induced by sensory qualities. When faced with this kind of problem it is usual to subdivide the term into more manageable perhaps partly operational definitions. Three meanings that capture aspects of consciousness are: (1 the neurology of the state of mind allowing coherent orientation to time and place (2 the selection of sensory or memorial information for awareness and (3 the voluntary control over overt responses. In each of these cases the mechanisms of consciousness overlap with one or more of the attentional networks that have been studied with the methods of cognitive neuroscience. In this paper we explore t

  11. Parameter estimation of feedback gain in a stochastic model of renal hemodynamics: differences between spontaneously hypertensive and Sprague-Dawley rats

    DEFF Research Database (Denmark)

    Ditlevsen, Susanne; Yip, Kay-Pong; Marsh, Donald J;

    2006-01-01

    Proximal tubular pressure shows periodic self-sustained oscillations in normotensive rats but highly irregular fluctuations in spontaneously hypertensive rats (SHR). Although we have suggested that the irregular fluctuations in SHR represent low-dimensional deterministic chaos in tubuloglomerular...

  12. Neuroimaging of consciousness

    Energy Technology Data Exchange (ETDEWEB)

    Cavanna, Andrea Eugenio [Birmingham Univ. (United Kingdom). Dept. of Neuropsychiatry; UCL Institute of Neurology, London (United Kingdom). Sobell Dept. of Motor, Neuroscience and Movement Disorders; Nani, Andrea [Birmingham Univ. (United Kingdom). Research Group BSMHFT; Blumenfeld, Hal [Yale University School of Medicine, New Haven, CT (United States). Depts. of Neurology, Neurobiology and Neurosurgery; Laureys, Steven (ed.) [Liege Univ. (Belgium). Cyclotron Research Centre

    2013-07-01

    An important reference work on a multidisciplinary and rapidly expanding area. Particular focus on the relevance of neuroimaging for the diagnosis and treatment of common neuropsychiatric disorders affecting consciousness. Written by world-class experts in the field. Relevant for clinicians, researchers, and scholars across different specialties. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This book presents the state of the art in neuroimaging exploration of the brain correlates of the alterations in consciousness across these conditions, with a particular focus on the potential applications for diagnosis and management. Although the book has a practical approach and is primarily targeted at neurologists, neuroradiologists, and psychiatrists, a wide range of researchers and health care professionals will find it an essential reference that explains the significance of neuroimaging of consciousness for clinical practice. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This

  13. Environmentally conscious patent histories

    Science.gov (United States)

    Crouch, Dennis D.; Crouch, Henry L.

    2004-02-01

    There is a need for investigators, legislators, and business leaders to understand the magnitude of innovation and discovery in the field of environmentally conscious technologies (ECTs). Knowledge of the "big picture" is important to providing a national and global account of actual environmental stewardship over the last twenty-five years. A recitation of the Environmental Protection Agency (EPA) supported Acts which have been enacted into law reveals one facet of the multifaceted dynamic of environmental consciousness. The popular discussion and debate, as well as partisan lobbying, which created the political forces leading to environmentally conscious legislation is another facet. A third facet is the corporate response to the threats and opportunities predicted by CEO"s and others through environmental scanning. This paper examines changes in environmentally conscious inventive effort by comparing data from United States Patents issued from 1976 through 2003. Patents are useful tool for measuring technological innovation because they are publicly available records of innovative activity. Although not all inventions result in patent applications, the monopoly rights granted on the invention give the inventor a strong incentive to obtain patents on any viable product or process. Among the results, we found a significant increase in patents relating to environmentally conscious products and processes during the period in question. Specifically, a dramatic increase in patent activity was seen for the decade of the 1990"s. Surprisingly, the patenting rate from 2000 to 2003 seems to have stabilized. Additionally public discussion of ECTs appears to have a positive impact on patent filings.

  14. Consciousness CLEARS the mind.

    Science.gov (United States)

    Grossberg, Stephen

    2007-11-01

    A full understanding of consciousness requires that we identify the brain processes from which conscious experiences emerge. What are these processes, and what is their utility in supporting successful adaptive behaviors? Adaptive Resonance Theory (ART) predicted a functional link between processes of Consciousness, Learning, Expectation, Attention, Resonance and Synchrony (CLEARS), including the prediction that "all conscious states are resonant states". This connection clarifies how brain dynamics enable a behaving individual to autonomously adapt in real time to a rapidly changing world. The present article reviews theoretical considerations that predicted these functional links, how they work, and some of the rapidly growing body of behavioral and brain data that have provided support for these predictions. The article also summarizes ART models that predict functional roles for identified cells in laminar thalamocortical circuits, including the six layered neocortical circuits and their interactions with specific primary and higher-order specific thalamic nuclei and nonspecific nuclei. These predictions include explanations of how slow perceptual learning can occur without conscious awareness, and why oscillation frequencies in the lower layers of neocortex are sometimes slower beta oscillations, rather than the higher-frequency gamma oscillations that occur more frequently in superficial cortical layers. ART traces these properties to the existence of intracortical feedback loops, and to reset mechanisms whereby thalamocortical mismatches use circuits such as the one from specific thalamic nuclei to nonspecific thalamic nuclei and then to layer 4 of neocortical areas via layers 1-to-5-to-6-to-4.

  15. The Conscious Individual

    Directory of Open Access Journals (Sweden)

    Ashok Natarajan

    2014-10-01

    Full Text Available This article traces the evolutionary development of human consciousness and its increasingly complex and sophisticated organization as human personality from the instinctive behavior of the animal and the subconscious conformity characteristic of early forms of human civilization through progressive stages of transition from physical to social to mental levels of awareness and from the undifferentiated social consciousness of the member of the tribe to the emergence of independent thinking, creativity and uniqueness, which characterize the Conscious Individual. The individual and the collective evolve in tandem. The collective imparts its acquired capacities to its members. The emerging individual acts as a catalyst to spur further development of the collective. Each stage of the journey is the same in essence and structure at progressively higher levels of consciousness and organization. The higher the level achieved by the collective in terms of quality and complexity, the greater the knowledge and organization demanded of the individual. The article ends by cataloging crucial points at which modern society is mired in outmoded conceptions, superstitious beliefs, pre-modern values and archaic institutions that obstruct humanity’s further evolution from problems and limitations to ever-expanding opportunities. The conscious individual is the key to that process.

  16. Abnormal endothelium-dependent microvascular dilator reactivity in pregnancies complicated by normotensive intrauterine growth restriction

    NARCIS (Netherlands)

    Koopmans, C.M.; Blaauw, Judith; van Pampus, Maria; Rakhorst, G.; Aarnoudse, J.G.

    2009-01-01

    OBJECTIVE: Normotensive intrauterine growth restriction and preeclampsia share a similar placenta pathophysiology, whereas maternal clinical manifestations differ. Clinical symptoms of preeclampsia are partly attributed to vascular endothelial dysfunction, but it is unclear whether this phenomenon p

  17. Cajal and consciousness. Introduction.

    Science.gov (United States)

    Marijuán, P C

    2001-04-01

    One hundred years after Santiago Ramón Cajal established the bases of modern neuroscience in his masterpiece Textura del sistema nervioso del hombre y de los vertebrados, the question is stated again: What is the status of consciousness today? The responses in this book, by contemporary leading figures of neuroscience, evolution, molecular biology, computer science, and quantum physics, collectively compose a fascinating conceptual landscape. Both the evolutionary emergence of consciousness and its development towards the highest level may be analyzed by a wealth of new theories and hypotheses, including Cajal's prescient ones. Some noticeable gaps remain, however. Celebrating the centennial of Textura is a timely occasion to reassess how close--and how far--our system of the sciences is to explaining consciousness.

  18. [Consciousness and emotion].

    Science.gov (United States)

    Carton, Solange

    2007-12-01

    This article focuses on the processes that lead to awareness of our own emotions, which deserve particular attention in contemporary models of emotional consciousness. The subjective component of emotion, or emotional experience, was for a long time the most neglected aspect in the study of emotions although it already constituted the initial point of discussion in the famous William James still asked question : What is an emotion? More than a century later, contemporary theories debate about this heritage. We examine the successive historic contributions to the question of the determinants of our own emotional experience: from James-Lange bodily changes to cognitive appraisal theories, also relating the major role that the fundamental emotions theory attributed to facial expressions. Twenty years after the debate about primacy of cognition or emotion, both physiological-somatic and cognitive components are integrated in contemporary approaches to emotions. However, their respective degree of implication varies according to the different levels of emotional consciousness which are modelized. It is on the last level that present models focus, level that leads to consciousness of our emotional experience, benefiting from the contributions of cognitive neurosciences. Models differ according to the role devoted to neuronal substrates in determining emotional experience, but they converge on the specification of a last level of consciousness, which is the only one that allows the subject to be conscious of emotion as it is experienced (feeling) and that what he is experiencing is an emotion. Then, different models of emotional consciousness account for different varieties of emotion experience and also for various cases of emotions, that is occurrence of emotion with a lack of awareness.

  19. Objects of consciousness.

    Science.gov (United States)

    Hoffman, Donald D; Prakash, Chetan

    2014-01-01

    Current models of visual perception typically assume that human vision estimates true properties of physical objects, properties that exist even if unperceived. However, recent studies of perceptual evolution, using evolutionary games and genetic algorithms, reveal that natural selection often drives true perceptions to extinction when they compete with perceptions tuned to fitness rather than truth: Perception guides adaptive behavior; it does not estimate a preexisting physical truth. Moreover, shifting from evolutionary biology to quantum physics, there is reason to disbelieve in preexisting physical truths: Certain interpretations of quantum theory deny that dynamical properties of physical objects have definite values when unobserved. In some of these interpretations the observer is fundamental, and wave functions are compendia of subjective probabilities, not preexisting elements of physical reality. These two considerations, from evolutionary biology and quantum physics, suggest that current models of object perception require fundamental reformulation. Here we begin such a reformulation, starting with a formal model of consciousness that we call a "conscious agent." We develop the dynamics of interacting conscious agents, and study how the perception of objects and space-time can emerge from such dynamics. We show that one particular object, the quantum free particle, has a wave function that is identical in form to the harmonic functions that characterize the asymptotic dynamics of conscious agents; particles are vibrations not of strings but of interacting conscious agents. This allows us to reinterpret physical properties such as position, momentum, and energy as properties of interacting conscious agents, rather than as preexisting physical truths. We sketch how this approach might extend to the perception of relativistic quantum objects, and to classical objects of macroscopic scale.

  20. Multiple intracranial hemorrhages in a normotensive demented patient: A probable cerebral amyloid angiopathy.

    Science.gov (United States)

    Chitsaz, Ahmad; Norouzi, Rasul; Marashi, Seyed Mohammad Javad; Salimianfard, Marzieh; Fard, Salman Abbasi

    2012-01-01

    Cerebral amyloid angiopathy (CAA) is the most common cause of lobar intracerebral hemorrhage. Repeated bleeding may be presented with vascular dementia. We have reported a 68-year-old normotensive demented patient with probable CAA presented with hemiparesia, headache and vomiting. According to the experience of this case, it is recommended to consider CAA for normotensive elderly patients presented with multiple and superficial intracerebral hemorrhage.

  1. Logical Evaluation of Consciousness: For Incorporating Consciousness into Machine Architecture

    CERN Document Server

    Padhy, C N

    2010-01-01

    Machine Consciousness is the study of consciousness in a biological, philosophical, mathematical and physical perspective and designing a model that can fit into a programmable system architecture. Prime objective of the study is to make the system architecture behave consciously like a biological model does. Present work has developed a feasible definition of consciousness, that characterizes consciousness with four parameters i.e., parasitic, symbiotic, self referral and reproduction. Present work has also developed a biologically inspired consciousness architecture that has following layers: quantum layer, cellular layer, organ layer and behavioral layer and traced the characteristics of consciousness at each layer. Finally, the work has estimated physical and algorithmic architecture to devise a system that can behave consciously.

  2. Perception, Action, and Consciousness

    DEFF Research Database (Denmark)

    What is the relationship between perception and action, between an organism and its environment, in explaining consciousness? These are issues at the heart of philosophy of mind and the cognitive sciences. This book explores the relationship between perception and action from a variety of interdi......What is the relationship between perception and action, between an organism and its environment, in explaining consciousness? These are issues at the heart of philosophy of mind and the cognitive sciences. This book explores the relationship between perception and action from a variety...

  3. The birth of consciousness.

    Science.gov (United States)

    Lagercrantz, Hugo

    2009-10-01

    Newborn infants fulfil some criteria of being conscious i.e. being aware of the body, the self and the world. They are able to differentiate between self and nonself touch, express emotions and show signs of shared feelings. They process sensory impressions including pain at a cortical level. They remember rhythmic sounds and vowels which they have been exposed to during fetal life. The spontaneous resting activity discovered in the cortex of newborn infants may correspond to what William James called "the stream of consciousness".

  4. Consciousness in the Universe

    Directory of Open Access Journals (Sweden)

    Khalil Chamcham

    2013-07-01

    Full Text Available So far we can identify at least three concepts within modern cosmology that bring into debate the question of consciousness in the universe: 1 Fine Tuning; 2 The Anthropic Principle and 3 The Multiverse. This does not exclude the question of the role of observer (i.e. consciousness in cosmology as developed within Quantum Physics: we observe the universe through quanta and any breakthrough in understanding the origin and nature of the universe will come only through a quantum theory of gravity […

  5. Impaired renal vascular response to a D-1-like receptor agonist but not to an ACE inhibitor in conscious spontaneously hypertensive rats

    NARCIS (Netherlands)

    de Vries, P.A.M.; Navis, Ger Jan; De Jong, P.E.; de Zeeuw, Dick

    1999-01-01

    The natriuretic response to a dopamine 1-like receptor agonist is blunted in spontaneously hypertensive rats (SHRs). Whether the renal vasodilator response to D-1-like receptor stimulation in SHRs is defective also is unclear. To determine whether the renal hemodynamic response to a D-1-like recepto

  6. EFFECT OF PRECURSOR LOADING ON THE SYNTHESIS RATE AND RELEASE OF DOPAMINE AND SEROTONIN IN THE STRIATUM - A MICRODIALYSIS STUDY IN CONSCIOUS RATS

    NARCIS (Netherlands)

    WESTERINK, BHC; DEVRIES, JB

    1991-01-01

    The effects of systemic administration of tyrosine and phenylalanine on the extracellular levels of tyrosine and dopamine were determined by microdialysis in the striatum of awake rats. In addition, the effects of these precursors on in vivo 3,4-dihydroxyphenylalanine (DOPA) formation were determine

  7. Chronic disorders of consciousness.

    Science.gov (United States)

    Xie, Qiuyou; Ni, Xiaoxiao; Yu, Ronghao; Li, Yuanqing; Huang, Ruiwang

    2017-08-01

    Over the last 20 years, studies have provided greater insight into disorders of consciousness (DOC), also known as altered state of consciousness. Increased brain residual functions have been identified in patients with DOC due to the successful application of novel next-generation imaging technologies. Many unconscious patients have now been confirmed to retain considerable cognitive functions. It is hoped that greater insight regarding the psychological state of patients may be achieved through the use of functional magnetic resonance imaging and brain-computer interfaces. However, issues surrounding the research and treatment of DOC remain problematic. These include differing opinions on the definition of consciousness, difficulties in diagnosis, assessment, prognosis and/or treatment, and newly emerging ethical, legal and social issues. To overcome these, appropriate care must be offered to patients with DOC by clinicians and families, as DOC patients may now be considered to live in more than just a vegetative state. The present article reviews the controversy surrounding the definition of consciousness and the reliability of novel technologies, prognostic prediction, communication with DOC patients and treatment methods. The ethical and social issues surrounding the treatment of DOC and future perspectives are also considered.

  8. Cybernetics and consciousness.

    Science.gov (United States)

    Trabka, J

    1999-01-01

    This paper is a review of hypotheses of consciousness which arose from application of the theory of information and regulation and the cybernetic theory of mathematical machines in medicine. The author presents these hypotheses on the examples of his own works.

  9. Consciousness and biological evolution.

    Science.gov (United States)

    Lindahl, B I

    1997-08-21

    It has been suggested that if the preservation and development of consciousness in the biological evolution is a result of natural selection, it is plausible that consciousness not only has been influenced by neural processes, but has had a survival value itself; and it could only have had this, if it had also been efficacious. This argument for mind-brain interaction is examined, both as the argument has been developed by William James and Karl Popper and as it has been discussed by C.D. Broad. The problem of identifying mental phenomena with certain neural phenomena is also addressed. The main conclusion of the analysis is that an explanation of the evolution of consciousness in Darwinian terms of natural selection does not rule out that consciousness may have evolved as a mere causally inert effect of the evolution of the nervous system, or that mental phenomena are identical with certain neural phenomena. However, the interactionistic theory still seems, more plausible and more fruitful for other reasons brought up in the discussion.

  10. Consciousness and the Brainstem.

    Science.gov (United States)

    Parvizi, Josef; Damasio, Antonio

    2001-01-01

    Summarizes a theoretical framework and set of hypotheses aimed at accounting for consciousness in neurobiological terms. Discusses the functional neuroanatomy of nuclei in the brainstem reticular formation. Notes that the views presented are compatible with the idea that the reticular formation modulates the electrophysiological activity of the…

  11. The mystery of consciousness

    CERN Document Server

    Searle, John R

    1997-01-01

    It has long been one of the most fundamental problems of philosophy, and it is now, John Searle writes, "the most important problem in the biological sciences": What is consciousness? Is my inner awareness of myself something separate from my body? In what began as a series of essays in The New York Review of Books, John Searle evaluates the positions on consciousness of such well-known scientists and philosophers as Francis Crick, Gerald Edelman, Roger Penrose, Daniel Dennett, David Chalmers, and Israel Rosenfield. He challenges claims that the mind works like a computer, and that brain functions can be reproduced by computer programs. With a sharp eye for confusion and contradiction, he points out which avenues of current research are most likely to come up with a biological examination of how conscious states are caused by the brain. Only when we understand how the brain works will we solve the mystery of consciousness, and only then will we begin to understand issues ranging from artificial intelligence...

  12. Hormonal and electrolyte responses to acute isohemic volume expansion in unanesthetized rats

    Science.gov (United States)

    Chenault, V. M.; Morris, M.; Lynch, C. D.; Maultsby, S. J.; Hutchins, P. M.

    1993-01-01

    This study was undertaken to explore the time course of the metabolic response to isohemic blood volume expansion (30%) in normotensive, unanesthetized Sprague-Dawley rats. Whole blood, drawn from a femoral artery catheter of conscious donor rats, was infused into the jugular vein of recipient rats. Blood samples were drawn from a carotid artery of recipient rats at time points beginning immediately post-volume expansion (IPVE) up through 5 days post-volume expansion (PVE). To characterize the attendant compensatory mechanisms, the plasma concentrations of electrolytes and fluid regulatory hormones were determined. Hematocrit began to raise IPVE and was significantly elevated above control IPVE 20, 30, 40, 60, and 90 min, and 2, 4, 6, 8, 12, and 24 hr PVE. Consistent with our current understanding of the hormonal response to excess volume, atrial natriuretic factor was significantly increased above the prevolume expansion (control) values 0-30 min PVE. Surprisingly, plasma aldosterone levels were significantly increased above control at 20 and 30 min and 6 hr PVE, whereas plasma renin activity was significantly decreased 30-40 min PVE. Plasma sodium was not changed from control values except for a significant increase at 6 hr post-volume expansion. Plasma potassium, osmolality, and arginine vasopressin levels were not altered by the volume expansion. These studies delineate the physiologic time scheme operative in the regulation of fluid volume during acute ischemic volume expansion.

  13. Self-Consciousness and Reactance.

    Science.gov (United States)

    Carver, Charles S.; Scheier, Michael F.

    1981-01-01

    Two studies examined the effects of dispositional self-consciousness on reactance. Men who were high in private self-consciousness displayed greater reactance responses to a coercive communication attempt. Women high in private self-consciousness exhibited greater reactance responses to a self-imposed threat to their freedom of choice. (Author)

  14. The minimally conscious state: defining the borders of consciousness.

    Science.gov (United States)

    Giacino, J T

    2005-01-01

    There is no agreement as to where the limits of consciousness lie, or even if these putative borders exist. Problems inherent to the study of consciousness continue to confound efforts to establish a universally accepted theory of consciousness. Consequently, clinical definitions of consciousness and unconsciousness are unavoidably arbitrary. Recently, a condition of severely altered consciousness has been described, which characterizes the borderzone between the vegetative state and so-called "normal" consciousness. This condition, referred to as the minimally conscious state (MCS), is distinguished from the vegetative state by the presence of minimal but clearly discernible behavioral evidence of self or environmental awareness. This chapter reviews the diagnostic criteria, pathophysiology, prognostic relevance, neurobehavioral assessment procedures and treatment implications associated with MCS.

  15. Muscular strength and incident hypertension in normotensive and prehypertensive men.

    Science.gov (United States)

    Maslow, Andréa L; Sui, Xuemei; Colabianchi, Natalie; Hussey, Jim; Blair, Steven N

    2010-02-01

    The protective effects of cardiorespiratory fitness (CRF) on hypertension (HTN) are well known; however, the association between muscular strength and incidence of HTN has yet to be examined. This study evaluated the strength-HTN association with and without accounting for CRF. Participants were 4147 men (age = 20-82 yr) in the Aerobics Center Longitudinal Study for whom an age-specific composite muscular strength score was computed from measures of a one-repetition maximal leg and a one-repetition maximal bench press. CRF was quantified by maximal treadmill exercise test time in minutes. Cox proportional hazards regression analysis was used to estimate hazard ratios (HR) and 95% confidence intervals of incident HTN events according to exposure categories. During a mean follow-up of 19 yr, there were 503 incident HTN cases. Multivariable-adjusted (excluding CRF) HR of HTN in normotensive men comparing middle- and high-strength thirds to the lowest third were not significant at 1.17 and 0.84, respectively. Multivariable-adjusted (excluding CRF) HR of HTN in baseline prehypertensive men comparing middle- and high-strength thirds to the lowest third were significant at 0.73 and 0.72 (P = 0.01 each), respectively. The association between muscular strength and incidence of HTN in baseline prehypertensive men was no longer significant after control for CRF (P = 0.26). The study indicated that middle and high levels of muscular strength were associated with a reduced risk of HTN in prehypertensive men only. However, this relationship was no longer significant after controlling for CRF.

  16. Determination of Glomerular Filtration Rate Using Micro-osmotic Pump in Conscious Rat%采用微渗透泵测定清醒大鼠肾小球滤过率

    Institute of Scientific and Technical Information of China (English)

    王静波; 王海涛; 汪照寒

    2011-01-01

    Objective Two non-radioactive methods for determining glomerular filtration rate ( GFR) in conscious rat using FITC-labeled inulin ( FITC-inulin) and micro-osmotic pumps were evaluated. Methods FITC-inulin (24% ) was dissolved in 0. 9% NaCl and the concentration decreased to 8% after 24 h of dialysis. Two micro-osmotic pumps filled with 200 |xL of 8% FITC-inulin were inserted into the peritoneal cavity of rats. After their complete recovery from anesthesia, the rats were housed individually in metabolic cages. Urine and the residual fluorescence remaining on the cages were collection over 24 h on day 7 after micro-osmotic pump implantation. Blood sample was collected through the saphenous vein at the end of 24-h urine collection. Only blood was sampled using the same method in another group. GFR was evaluated on day 7 after micro-osmotic pump implantation using two methods expressed in microliters per minute, microliters per minute per kilogram body weight and per gram kidney weight. Results Based on the approach measuringurinary inulin clearance with urine collection and without urine collection the estimated GFR was (2. 31 ±0. 33) microliters per minute and ( 2. 53 ± 0. 33) microliters per minute (P = 0. 564) , respectively. These values of GFR in conscious rats were only ca. 70% of that obtained in anesthetized rats determined in other previous studies. It was revealed that anesthesia may significantly influence GFR. Conclusions The results of the present study demonstrate the feasibility of the osmotic micropump approach to monitor GFR in conscious rat using FITC-inulin. Especially, the method without collecting urine is more convenient.%目的 分析以荧光素异硫氰酸酯标记的菊粉(FITC-菊粉)作为标记物,通过微渗透泵,在大鼠清醒状态下,采用菊粉尿排泄率方法测定肾小球滤过率的可行性.方法 将FITC -菊粉溶解在生理盐水中配成浓度为24%的溶液,经滤过后(浓度降至8%)装在微

  17. [Functional pathophysiology of consciousness].

    Science.gov (United States)

    Jellinger, Kurt A

    2009-01-01

    Consciousness (Latin conscientia "moral conscience"), according to the English philosopher John Locke (1632-1704) [103], is the awareness of all that occurs in the mind of a person, whereas the American philosopher John Searle (2000) defined it as "inner qualitative, subjective states and processes of awareness". In modern science it is defined as a continuous state of full awareness of the Self and one's relationship to the external and internal environment, describing the degree of wakefulness in which an organism recognizes stimuli. This widely discussed biological term for complex neuronal processes that allow an individuum to recognize itself and its environment and to act accordingly, has been and still is the subject of much research in philosophy and natural/neuroscience. Its definition is often used for awareness and recognition, too. While the Egyptians in the papyrus Edwin Smith already recognized the brain as the seat of consciousness, René Descartes (1644 [36]) believed its special structure should be "a small gland in the middle", but the anatomical structures and physiological processes involved in consciousness were elucidated only in the middle of the 20th century. Neuronal substrates include several functional networks that are hierarchically organized and cooperate functionally. The lowest level is the mesencephalic formatio reticularis and its projections to the thalamus that were identified als ascending reticular system (ARAS) by the classical experiments of Moruzzi and Magoun, whereas later analyses of patients with impaired consciousness provided further insights. The mesencephalic ARAS as motor of the function of higher structures projects 1. via the reticular thalamus diffusely to the cortex, 2. via hypothalamus to the basal forebrain and limbic system, and 3. to the medial raphe of the brainstem and locus coeruleus and their diffuse cortical projections. The reticular system is stimulated directly and indirectly via numerous collaterals

  18. Strain differences in baroceptor reflex in adult Wistar Kyoto rats

    Directory of Open Access Journals (Sweden)

    Vitor E. Valenti

    2010-01-01

    Full Text Available OBJECTIVES: A subset of normotensive Sprague-Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype. METHODS: Male Wistar Kyoto (WKY rats (16 weeks old were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP and heart rate (HR. Baroreflex gain was calculated as the ratio between change in HR and MAP variation (ΔHR/ΔMAP in response to a depressor dose of sodium nitroprusside (SNP, 50 µg/kg, i.v. and a pressor dose of phenylephrine (PE, 8 µg/kg, i.v.. Rats were divided into four groups: 1 low bradycardic baroreflex (LB, baroreflex gain (BG between -1 and -2 bpm/mmHg tested with PE; 2 high bradycardic baroreflex (HB, BG < -2 bpm/mmHg tested with PE; 3 low tachycardic baroreflex (LT, BG between -1 and -2 bpm/mmHg tested with SNP and; 4 high tachycardic baroreflex (HT, BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05. RESULTS: Approximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP. CONCLUSION: There is variability regarding baroreflex sensitivity among WKY rats from the same laboratory.

  19. Diesel exhaust worsens cardiac conduction instability in dobutamine-challenged spontaneously hypertensive rats

    Science.gov (United States)

    This study demonstrated that diesel exhaust worsened arrhythmia and cardiac function during dobutamine (simulated exercise) challenge in normotensive and hypertensive rats. The data presented here are a mathematically-derived indicator of cardiac risk, which can be used for risk ...

  20. Are There Levels of Consciousness?

    Science.gov (United States)

    Bayne, Tim; Hohwy, Jakob; Owen, Adrian M

    2016-06-01

    The notion of a level of consciousness is a key construct in the science of consciousness. Not only is the term employed to describe the global states of consciousness that are associated with post-comatose disorders, epileptic absence seizures, anaesthesia, and sleep, it plays an increasingly influential role in theoretical and methodological contexts. However, it is far from clear what precisely a level of consciousness is supposed to be. This paper argues that the levels-based framework for conceptualizing global states of consciousness is untenable and develops in its place a multidimensional account of global states. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Grooming behavior of spontaneously hypertensive rats

    NARCIS (Netherlands)

    Buuse, M. van den; Jong, Wybren de

    1987-01-01

    In an open field spontaneously hypertensive rats (SHR) exhibited lower scores for grooming when compared to their normotensive controls, the Wistar Kyoto rats (WKY). After i.c.v. injection of 1 μg ACTH1–24 cumulative 50-min grooming scores were lower in SHR. Analysis of subscores indicated that the

  2. [The somato-sympathetic and somato-somatic reflexes in the spontaneous hypertensive rats].

    Science.gov (United States)

    Shcherbin, Iu I; Tsyrlin, V A

    2014-01-01

    In anaesthetized normotensive (Wistar) and hypertensive (SHR) rats, sympathetic and somatic reflexes were studied before and after cervical spinal cord transection. Single shock stimulation of a peripheral afferent nerve of brachial plexus produced reflex discharges in the cervical sympathetic trunk and the radial nerve. In rats with intact brain stem, evoked response in the cervical sympathetic trunk was composed of three components, but evoked response in radial nerve consisted of two components. The total somato-sympathetic reflex in hypertensive rats was more on 54 % than the somato-sympathetic reflex in normotensive rats. The total somato-somatic reflex in hypertensive rats was more on 70 % than the somato-somatic reflex in normotensive rats. In rats with transected brain stem, evoked response in the cervical sympathetic trunk was composed of two components, but evoked response in radial nerve consisted of one component. After neuraxis transection the total sympathetic and somatic reflexes in normotensive rats decreased by 85 and 83 %, respectively. The total sympathetic and somatic reflexes in hypertensive rats decreased by 88 and 84 %, respectively. However, the peak value of evoked discharges in sympathetic and somatic nerves were more in hypertensive rats than in normotensive rats. Suprasegmental and spinal mechanisms responsible for the augmentation of both sympathetic and somatic reflexes are discussed.

  3. Defining the states of consciousness.

    Science.gov (United States)

    Tassi, P; Muzet, A

    2001-03-01

    Consciousness remains an elusive concept due to the difficulty to define what has been regarded for many years as a subjective experience, therefore irrelevant for scientific study. Recent development in this field of research has allowed to provide some new insight to a possible way to define consciousness. Going through the extensive literature in this domain, several perspectives are proposed to define this concept. (1) Consciousness and Attention may not reflect the same process. (2) Consciousness during wake and sleep may not involve the same mechanisms. (3) Besides physiological states of consciousness, human beings can experience modified states of consciousness either by self-training (transcendental meditation, hypnosis, etc.) or by drug intake (hallucinogens, anaesthetics, etc.). Altogether, we address the question of a more precise terminology, given the theoretical weight words can convey. To this respect, we propose different definitions for concepts like consciousness, vigilance, arousal and alertness as candidates to separate functional entities.

  4. Perception, Action, and Consciousness

    DEFF Research Database (Denmark)

    What is the relationship between perception and action, between an organism and its environment, in explaining consciousness? These are issues at the heart of philosophy of mind and the cognitive sciences. This book explores the relationship between perception and action from a variety of interdi......What is the relationship between perception and action, between an organism and its environment, in explaining consciousness? These are issues at the heart of philosophy of mind and the cognitive sciences. This book explores the relationship between perception and action from a variety...... of interdisciplinary perspectives, ranging from theoretical discussion of concepts to findings from recent scientific studies. It incorporates contributions from leading philosophers, psychologists, neuroscientists, and an artificial intelligence theorist. The contributions take a range of positions with respect...

  5. Accuracy and precision of oscillometric blood pressure in standing conscious horses

    DEFF Research Database (Denmark)

    Olsen, Emil; Pedersen, Tilde Louise Skovgaard; Robinson, Rebecca

    2016-01-01

    BACKGROUND: Arterial blood pressure (BP) is a relevant clinical parameter that can be measured in standing conscious horses to assess tissue perfusion or pain. However, there are no validated oscillometric noninvasive blood pressure (NIBP) devices for use in horses. ANIMALS: Seven healthy horses...... from a teaching and research herd. HYPOTHESIS/OBJECTIVE: To evaluate the accuracy and precision of systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) in conscious horses obtained with an oscillometric NIBP device when compared to invasively measured...... arterial BP. METHODS: An arterial catheter was placed in the facial or transverse facial artery and connected to a pressure transducer. A cuff for NIBP was placed around the tail base. The BP was recorded during normotension, dobutamine-induced hypertension, and subnormal BP induced by acepromazine...

  6. The rise of machine consciousness: studying consciousness with computational models.

    Science.gov (United States)

    Reggia, James A

    2013-08-01

    Efforts to create computational models of consciousness have accelerated over the last two decades, creating a field that has become known as artificial consciousness. There have been two main motivations for this controversial work: to develop a better scientific understanding of the nature of human/animal consciousness and to produce machines that genuinely exhibit conscious awareness. This review begins by briefly explaining some of the concepts and terminology used by investigators working on machine consciousness, and summarizes key neurobiological correlates of human consciousness that are particularly relevant to past computational studies. Models of consciousness developed over the last twenty years are then surveyed. These models are largely found to fall into five categories based on the fundamental issue that their developers have selected as being most central to consciousness: a global workspace, information integration, an internal self-model, higher-level representations, or attention mechanisms. For each of these five categories, an overview of past work is given, a representative example is presented in some detail to illustrate the approach, and comments are provided on the contributions and limitations of the methodology. Three conclusions are offered about the state of the field based on this review: (1) computational modeling has become an effective and accepted methodology for the scientific study of consciousness, (2) existing computational models have successfully captured a number of neurobiological, cognitive, and behavioral correlates of conscious information processing as machine simulations, and (3) no existing approach to artificial consciousness has presented a compelling demonstration of phenomenal machine consciousness, or even clear evidence that artificial phenomenal consciousness will eventually be possible. The paper concludes by discussing the importance of continuing work in this area, considering the ethical issues it raises

  7. The Impaired Consciousness

    Directory of Open Access Journals (Sweden)

    Docu Any Axelerad

    2017-05-01

    Full Text Available The ”persistent vegetative state” (PVS has the main attention for us in identifying the examples of consciousness that suffer structural injury. PVS is a state that the patient has the ability to open eyes spontaneously, but without responses to threat, verbalization or other pain defend. Several factors that lead to such state, among which the use of drugs is mostly researched, prolong impaired consciousness as a clinical and personal judgment of this condition. The patients with comatose from a destructive structural injury never regain the conscious state due to widespread structural damage. Any clinical review on this is based on bodily changes observation with impact on the clinical diagnosis of prolonged comatose states as largely descriptive. Eye movements need the most attention because its response to approaching objects distinguishes between a PVS (inconsistent or absent, akinetic mutism (no stacking but spontaneous focusing on moving targets, and MCS (always present. Distinguish between this three conditions needs an interdisciplinary intervention (neurologist or rehabilitation physicians.

  8. Association between mortality and blood pressure variability in hypertensive and normotensive elders: A cohort study.

    Science.gov (United States)

    Weiss, Avraham; Beloosesky, Yichayaou; Koren-Morag, Nira; Grossman, Alon

    2017-08-01

    To evaluate the association between blood pressure variability (BPV) and mortality in the elderly, all blood pressure measurements recorded in a cohort of individuals 65 years and older were collected and the association between BPV coefficient of variation (BPV divided by mean arterial pressure) was calculated. Mortality during a 10-year period was compared between BPV coefficient of variation quartiles. Overall, 39 502 individuals 65 years and older were included in the analysis, of which 31 737 (80.3%) were hypertensive; 12 817 (32.4%) individuals died during the study period. Mortality was lower in the second and third blood pressure quartiles compared with the first quartile in both the normotensive and hypertensive groups. In both normotensive and hypertensive individuals, mortality was higher in the fourth quartile, but it was more pronounced in normotensive individuals (odds ratio, 1.18; 95% confidence interval, 1.06-1.31 in hypertensive individuals vs odds ratio, 1.27; 95% confidence interval, 1.17-1.37 in normotensive individuals). High and low BPV are associated with mortality in both hypertensive and normotensive elders. ©2017 Wiley Periodicals, Inc.

  9. [Self-consciousness, consciousness of the other and dementias].

    Science.gov (United States)

    Gil, Roger

    2007-06-01

    Studies of self-consciousness in dementia concern essentially anosognosia or the loss of insight. However, Self-consciousness is multifaceted: it includes awareness of the body, perceptions, one's own history, identity, and one's own projects. Self-consciousness is linked to consciousness of others i.e. to social cognition supported by identification of others, but also by comprehension of facial expression of emotions, comprehension and expression of emotional prosody, pragmatic abilities, ability to infer other's people's mental states, thoughts, and feelings (theory of mind and empathy), knowledge of social norms and rules, social reasoning. The subtypes of dementias (and namely Alzheimer's disease and frontotemporal dementia) affect heterogeneously the different aspects of the self-and other-consciousness. Further studies are needed for a better knowledge of the complex relationship between Self-consciousness, social cognition, decision making and neuropsychiatric symptoms and behavioral disturbances occurring in demented patients.

  10. The Neurogenetic Correlates of Consciousness

    Science.gov (United States)

    Grandy, John K.

    2013-09-01

    The neurogenetic correlates of consciousness (NgCC) is a new field of consciousness studies that focuses on genes that have an effect on or are involved in the continuum of neuron-based consciousness. A framework of consciousness based on the neural correlates of consciousness (NCC) has already been established by Francis Crick and Christof Kock. In this work I propose that there are NgCC underlying the NCC which are both active during the conscious experience. So how are genes involved? There are two significant connections between DNA and neurons that are involved in the conscious experience. First, any brain system can be adversely affected by underlying genetic abnormalities which can be expressed in an individual at birth, in adulthood, or later in life. Second, the DNA molecule does not lay dormant while the neuron runs on autopilot. DNA is active in translating and transcribing RNA and protein products that are utilized during neuron functioning. Without these products being continuously produced by the DNA during a conscious experience the neurons would cease to function correctly and be rendered unable to provide a continuum of human consciousness. Consequently, in addition to NCC, NgCC must be factored in when appreciating a conscious event. In this work I will discuss and explain some NgCC citing several examples.

  11. Are we explaining consciousness yet?

    Science.gov (United States)

    Dennett, D

    2001-04-01

    Theorists are converging from quite different quarters on a version of the global neuronal workspace model of consciousness, but there are residual confusions to be dissolved. In particular, theorists must resist the temptation to see global accessibility as the cause of consciousness (as if consciousness were some other, further condition); rather, it is consciousness. A useful metaphor for keeping this elusive idea in focus is that consciousness is rather like fame in the brain. It is not a privileged medium of representation, or an added property some states have; it is the very mutual accessibility that gives some informational states the powers that come with a subject's consciousness of that information. Like fame, consciousness is not a momentary condition, or a purely dispositional state, but rather a matter of actual influence over time. Theorists who take on the task of accounting for the aftermath that is critical for consciousness often appear to be leaving out the Subject of consciousness, when in fact they are providing an analysis of the Subject, a necessary component in any serious theory of consciousness.

  12. The biological function of consciousness

    Science.gov (United States)

    Earl, Brian

    2014-01-01

    This research is an investigation of whether consciousness—one's ongoing experience—influences one's behavior and, if so, how. Analysis of the components, structure, properties, and temporal sequences of consciousness has established that, (1) contrary to one's intuitive understanding, consciousness does not have an active, executive role in determining behavior; (2) consciousness does have a biological function; and (3) consciousness is solely information in various forms. Consciousness is associated with a flexible response mechanism (FRM) for decision-making, planning, and generally responding in nonautomatic ways. The FRM generates responses by manipulating information and, to function effectively, its data input must be restricted to task-relevant information. The properties of consciousness correspond to the various input requirements of the FRM; and when important information is missing from consciousness, functions of the FRM are adversely affected; both of which indicate that consciousness is the input data to the FRM. Qualitative and quantitative information (shape, size, location, etc.) are incorporated into the input data by a qualia array of colors, sounds, and so on, which makes the input conscious. This view of the biological function of consciousness provides an explanation why we have experiences; why we have emotional and other feelings, and why their loss is associated with poor decision-making; why blindsight patients do not spontaneously initiate responses to events in their blind field; why counter-habitual actions are only possible when the intended action is in mind; and the reason for inattentional blindness. PMID:25140159

  13. Impact of emotion on consciousness: positive stimuli enhance conscious reportability.

    Directory of Open Access Journals (Sweden)

    Kristine Rømer Thomsen

    Full Text Available Emotion and reward have been proposed to be closely linked to conscious experience, but empirical data are lacking. The anterior cingulate cortex (ACC plays a central role in the hedonic dimension of conscious experience; thus potentially a key region in interactions between emotion and consciousness. Here we tested the impact of emotion on conscious experience, and directly investigated the role of the ACC. We used a masked paradigm that measures conscious reportability in terms of subjective confidence and objective accuracy in identifying the briefly presented stimulus in a forced-choice test. By manipulating the emotional valence (positive, neutral, negative and the presentation time (16 ms, 32 ms, 80 ms we measured the impact of these variables on conscious and subliminal (i.e. below threshold processing. First, we tested normal participants using face and word stimuli. Results showed that participants were more confident and accurate when consciously seeing happy versus sad/neutral faces and words. When stimuli were presented subliminally, we found no effect of emotion. To investigate the neural basis of this impact of emotion, we recorded local field potentials (LFPs directly in the ACC in a chronic pain patient. Behavioural findings were replicated: the patient was more confident and accurate when (consciously seeing happy versus sad faces, while no effect was seen in subliminal trials. Mirroring behavioural findings, we found significant differences in the LFPs after around 500 ms (lasting 30 ms in conscious trials between happy and sad faces, while no effect was found in subliminal trials. We thus demonstrate a striking impact of emotion on conscious experience, with positive emotional stimuli enhancing conscious reportability. In line with previous studies, the data indicate a key role of the ACC, but goes beyond earlier work by providing the first direct evidence of interaction between emotion and conscious experience in the human

  14. Comparison of the hemodynamic effects of etomidate between hypertensive and normotensive patients

    Directory of Open Access Journals (Sweden)

    Hayrettin Daşkaya

    2014-06-01

    Full Text Available Objective: Comparison of the hemodynamic effect of ethomidate induction in normotensive and hypertensive patients. Methods: Forty ASA 1-2 patients were included. After informed consent were obtained, patients were divided into two group; Group H: Hypertensive patients, Group N: Normotensive patients. Fentanile and midazolam were administrated for premedication. Anesthesia induction was performed by etomidate 0.3 mg/kg and rocuronium 0.6 mg/kg. Arterial pressures and heart rates were measured at certain intervals: control, pre-intubation and 1, 3 and 5 min post-intubation. Myoclonic movements and hemodynamic parameters were noted by an anesthetist who was masked to the groups. Results: Hemodynamic parameters were higher in hypertensive patients but were in clinically tolerable limits. Conclusion: No hemodynamic instability was observed in anesthesia induction with ethomidate in neither hypertensive nor normotensive patients. J Clin Exp Invest 2014; 5 (2: 164-168

  15. New obesity indices and adipokines in normotensive patients and patients with hypertension: comparative pilot analysis.

    Science.gov (United States)

    Stepien, Mariusz; Stepien, Anna; Banach, Maciej; Wlazel, Rafal N; Paradowski, Marek; Rizzo, Manfredi; Toth, Peter P; Rysz, Jacek

    2014-04-01

    We compared the obesity parameters and selected adipokines-leptin, adiponectin, and resistin-in obese patients with hypertension and normotensive patients. A total of 67 nondiabetic obese outpatients were divided into 2 groups: A-hypertensive and B-normotensive. Serum levels of leptin, adiponectin, resistin, and insulin were measured. Weight, height, waist circumference, and hip circumference were measured to calculate waist-to-hip ratio (WHR), weight-to-height ratio, visceral adiposity index, and body adiposity index (BAI). Among patients with hypertension, significant positive correlations were observed between leptin and body mass index and BAI (r = .31 and r = .63, respectively). In normotensive patients, leptin positively correlated with BAI (r = .73, P obesity and leptin are associated with hypertension in obese patients.

  16. Linalool-rich rosewood oil induces vago-vagal bradycardic and depressor reflex in rats.

    Science.gov (United States)

    de Siqueira, Rodrigo José; Rodrigues, Karilane Maria Silvino; da Silva, Moisés Tolentino Bento; Correia Junior, Carlos Antônio Barros; Duarte, Gloria Pinto; Magalhães, Pedro Jorge Caldas; dos Santos, Armênio Aguiar; Maia, José Guilherme Soares; da Cunha, Pergentino José Sousa; Lahlou, Saad

    2014-01-01

    Cardiovascular effects of the linalool-rich essential oil of Aniba rosaeodora (here named as EOAR) in normotensive rats were investigated. In anesthetized rats, intravenous (i.v.) injection of EOAR induced dose-dependent biphasic hypotension and bradycardia. Emphasis was given to the first phase (phase 1) of the cardiovascular effects, which is rapid (onset time of 1-3 s) and not observed in animals submitted to bilateral vagotomy or selective blockade of neural conduction of vagal C-fibre afferents by perineural treatment with capsaicin. Phase 1 was also absent when EOAR was directly injected into the left ventricle injection, but it was unaltered by i.v. pretreatment with capsazepine, ondansetron or HC030031. In conscious rats, EOAR induced rapid and monophasic hypotensive and bradycardiac (phase 1) effects that were abolished by i.v. methylatropine. In endothelium-intact aortic rings, EOAR fully relaxed phenylephrine-induced contractions in a concentration-dependent manner. The present findings reveal that phase 1 of the bradycardiac and depressor responses induced by EOAR has a vago-vagal reflex origin resulting from the vagal pulmonary afferents stimulation. Such phenomenon appears not to involve the recruitment of C-fibre afferents expressing 5HT3 receptors or the two chemosensory ion channels TRPV1 and TRPA1 . Phase 2 hypotensive response appears resulting from a direct vasodilatory action.

  17. Beneficial impact of ramipril on left ventricular hypertrophy in normotensive nonalbuminuric NIDDM patients

    DEFF Research Database (Denmark)

    Nielsen, F S; Sato, A; Ali, S

    1998-01-01

    OBJECTIVE: To evaluate the effect of the ACE inhibitor ramipril as compared with placebo on left ventricular mass index (LVMI) in normotensive, nonalbuminuric NIDDM patients with left ventricular hypertrophy (LVH). Patients with NIDDM are characterized by excessive cardiovascular morbidity...... and mortality, and LVH, an independent risk factor for cardiac events, is often present in NIDDM patients. RESEARCH DESIGN AND METHODS: A total of 38 normotensive, nonalbuminuric (albuminuria 131 g/m2 in men and > 100 g/m2 in women) were enrolled in a 6-month...

  18. LEGAL CONSCIOUSNESS AND LEGAL CULTURE

    OpenAIRE

    BOSHNO SVETLANA

    2016-01-01

    This chapter of the course manual in jurisprudence discloses the notion of legal consciousness. Comprehending law, legislation, principal state and legal institutes manifests itself in law enforcement. One shouldn't absolutize the role of legislation as it is, since it is only after texts of normative acts go through the prism of legal consciousness of the actor's personality, they convert into some behaviour patterns. Legal consciousness has a definite structure, it is divided into levels. L...

  19. Strategies for measuring machine consciousness

    OpenAIRE

    2009-01-01

    The accurate measurement of the level of consciousness of a creature remains a major scientific challenge, nevertheless a number of new accounts that attempt to address this problem have been proposed recently. In this paper we analyze the principles of these new measures of consciousness along with other classical approaches focusing on their applicability to Machine Consciousness (MC). Furthermore, we propose a set of requirements of what we think a suitable measure for MC should be, discus...

  20. Study of Consciousness

    Directory of Open Access Journals (Sweden)

    Samuel Lee

    2011-01-01

    Full Text Available The human brain is a powerful organ that controls most of the body. Researchers around the world have long tried to uncover how the brain operates, how memories are formed and stored. Our understanding of neurological diseases such as Alzheimer's and Parkinson's disease has been rapidly improving, yet much remains to be done. In this work, we attempt to study changes in intracranial pressure (ICP for a 12-hour period and discuss whether the resulting estimates could be used as a measure of consciousness.

  1. Consciousness -- A Verifiable Prediction

    Science.gov (United States)

    Panchapakesan, N.

    2014-07-01

    Consciousness may or may not be completely within the realm of science. We have argued elsewhere that there is a high probability that it is not within the purview of science, just like humanities and arts are outside science. Even social sciences do not come under science when human interactions are involved. Here, we suggest a possible experiment to decide whether it is part of science. We suggest that a scientific signal may be available to investigate the prediction in the form of an electromagnetic brainwave background radiation.

  2. Environment Conscious Ceramics (Ecoceramics)

    Science.gov (United States)

    Singh, Mrityunjay; Levine, Stanley R. (Technical Monitor)

    2000-01-01

    Environment conscious ceramics (Ecoceramics) are a new class of materials, which can be produced with renewable natural resources (wood) or wood wastes (wood sawdust). Silicon carbide-based ecoceramics have been fabricated by reactive infiltration of carbonaceous preforms by molten silicon or silicon-refractory metal alloys. These carbonaceous preforms have been fabricated by pyrolysis of solid wood bodies at 1000 C. The fabrication approach, microstructure, and mechanical properties of SiC-based ecoceramics are presented. Ecoceramics have tailorable properties and behave like ceramic materials manufactured by conventional approaches.

  3. Behavioral Methods in Consciousness Research

    DEFF Research Database (Denmark)

    that the research literature has expanded greatly, particularly in cognitive neuroscience and cognitive science. Interestingly, this scientific work has made use of a wide variety of different methods without much consensus on how one might in fact measure subjective consciousness. This situation makes...... it potentially impossible to compare and contrast experimental findings, and difficult to show that consciousness research is a discipline going in a particular direction or has a particular focus. This book provides an overview of methods and approaches for studying consciousness. It aims to make progress...... giving concrete tools for how to investigate consciousness in combination with theoretical discussions of possibilities and limitations of each method...

  4. Basic consciousness of the newborn.

    Science.gov (United States)

    Lagercrantz, Hugo; Changeux, Jean-Pierre

    2010-06-01

    The newborn shows several signs of consciousness, such as being awake and aware of him/herself and mother. The infant processes olfactory and painful inputs in the cortex, where consciousness is believed to be localized. Furthermore, the newborn expresses primary emotions such as joy, disgust, and surprise and remember rhymes and vowels to which he or she has been exposed during fetal life. Thus, the newborn infant fulfills the criteria of displaying a basic level of consciousness, being aware of its body and him/her-self and somewhat about the external world. Preterm infants may be conscious to a limited degree from about 25 weeks, when the thalamocortical connections are established.

  5. Sodium homeostasis in lymphocytes and blood pressure alterations before and during salt restriction in normotensives and in essential hypertensives

    DEFF Research Database (Denmark)

    Jest, P; Pedersen, K E; Klitgaard, N A

    1986-01-01

    Blood pressure, lymphocytic sodium content and sodium efflux were studied in hypertensive and normotensive subjects during salt restriction. Diastolic blood pressure decreased significantly in both groups. In essential hypertension the initial high lymphocyte sodium content decreased during salt...... mechanisms with regard to lymphocyte sodium metabolism differs between hypertensive and normotensive subjects....

  6. Modulation of mGlu2 Receptors, but Not PDE10A Inhibition Normalizes Pharmacologically-Induced Deviance in Auditory Evoked Potentials and Oscillations in Conscious Rats.

    Directory of Open Access Journals (Sweden)

    Abdallah Ahnaou

    Full Text Available Improvement of cognitive impairments represents a high medical need in the development of new antipsychotics. Aberrant EEG gamma oscillations and reductions in the P1/N1 complex peak amplitude of the auditory evoked potential (AEP are neurophysiological biomarkers for schizophrenia that indicate disruption in sensory information processing. Inhibition of phosphodiesterase (i.e. PDE10A and activation of metabotropic glutamate receptor (mGluR2 signaling are believed to provide antipsychotic efficacy in schizophrenia, but it is unclear whether this occurs with cognition-enhancing potential. The present study used the auditory paired click paradigm in passive awake Sprague Dawley rats to 1 model disruption of AEP waveforms and oscillations as observed in schizophrenia by peripheral administration of amphetamine and the N-methyl-D-aspartate (NMDA antagonist phencyclidine (PCP; 2 confirm the potential of the antipsychotics risperidone and olanzapine to attenuate these disruptions; 3 evaluate the potential of mGluR2 agonist LY404039 and PDE10 inhibitor PQ-10 to improve AEP deficits in both the amphetamine and PCP models. PCP and amphetamine disrupted auditory information processing to the first click, associated with suppression of the P1/N1 complex peak amplitude, and increased cortical gamma oscillations. Risperidone and olanzapine normalized PCP and amphetamine-induced abnormalities in AEP waveforms and aberrant gamma/alpha oscillations, respectively. LY404039 increased P1/N1 complex peak amplitudes and potently attenuated the disruptive effects of both PCP and amphetamine on AEPs amplitudes and oscillations. However, PQ-10 failed to show such effect in either models. These outcomes indicate that modulation of the mGluR2 results in effective restoration of abnormalities in AEP components in two widely used animal models of psychosis, whereas PDE10A inhibition does not.

  7. Exercise gas transport determinants in elderly normotensive and hypertensive humans.

    Science.gov (United States)

    Petrella, R J; Cunningham, D A; Paterson, D H

    1999-01-01

    This study examined the effect of the phenylalkylamine calcium channel blocker verapamil, on resting left ventricular (LV) function and O2 uptake rate (VO2) during exercise at maximal and submaximal work rates. Nine older hypertensive (71 years; OH), 10 older sedentary normotensive (69 years; OS), 10 older active (71 years; OA) and 10 young (24 years; Y) individuals volunteered. Studies were completed in the control condition and 4-6 h following 240 mg verapamil SR per os. Resting LV systolic (fractional shortening; FS) and diastolic (early: late (E/A) flow velocity ratio and isovolumic relaxation time (IVRT) were measured by Doppler echocardiography. Maximal oxygen uptake (VO2,max) and, on subsequent test days, four transitions to and from a 6 min square wave exercise perturbation at a sub-anaerobic threshold intensity of 40 W (OH, OS, OA) or 100 W (Y) for determination of VO2 kinetics were performed on a cycle ergometer. Breath-by-breath VO2 transients were fitted with a monoexponential equation, starting at phase 2 of the response, while heart rate (HR) was fitted from phase 1, for the determination of the time constant of VO2 (tau VO2) and HR (tau HR). Baseline left ventricular FS was significantly greater in the OS (32%), OA (34%) and Y (34%) than in the OH (23%) groups, while E/A was significantly greater in the OA (1.16) and Y (2.34) than in the OH (0.9) and OS (0.82) groups (P < 0.05). Baseline VO2,max was higher and tau VO2 faster in the young (41.4 ml kg-1 min-1; 25.2 s) than in the older groups and in the OA (28.8 ml kg-1 min-1; 44.3 s) than in both OH (20.8 ml kg-1 min-1; 71.3 s) and OS (22.0 ml kg-1 min-1; 59.5 s) groups (P < 0.05). Heart rate kinetics showed similar differences to VO2 kinetics among the groups. After verapamil, no significant changes in FS, E/A or IVRT were observed in the OA and Y groups. In the OH group, FS (32%) and E/A (1.15) increased while IVRT decreased significantly (from 0.103 to 0.07; P < 0.05). In the OS group, only E

  8. Hallmarks of consciousness.

    Science.gov (United States)

    Butler, Ann B

    2012-01-01

    Consciousness, ranging from the primary, or perceptual, level to high levels that include a sense of self, can be identified in various organisms by a set of hallmarks that include behavioral, neural and phenomenal and/or informational. Behavioral hallmarks include those that indicate high cognitive abilities, such behavioral flexibility, verbal abilities, episodic memories, theory of mind, object constancy, transitive inference and multistability, all of which have been demonstrated in birds as well as in primates. Neural hallmarks include the thalamocortical model for mammals and similar circuitry in some nonmammalian taxa. Informational hallmarks include sensorimotor awareness, as provided by somatosensory and/or lateral line systems, which may form the basis for the sense of self and distinguishing self from nonself, as well as other sensory information, such as the richness and quantity of color and form information obtained by the visual system. The comparative method reveals a correlation of these different types of hallmarks with each other in their degree of development, which thus may be indicative of the level of consciousness present in a particular species.

  9. What is consciousness?

    Science.gov (United States)

    Solms, M

    1997-01-01

    In the past few years scientists and scholars in a variety of disciplines have been making concerted efforts to answer an ancient question, namely, How exactly do the physical processes in the brain cause consciousness? What is distinctive about the way in which modern scientists and scholars are approaching this question is that they are treating it as a scientific problem rather than a metaphysical one. This transition reflects the air of expectation in contemporary cognitive science to the effect that an empirical solution is imminent to a philosophical problem that previously was considered insoluble. Nevertheless, a recent authoritative review of the publications of such leading contemporary workers in the field as Francis Crick, Daniel Dennett, Gerald Edelman, Roger Penrose, and Israel Rosenfield has concluded that they have all failed to provide a satisfactory answer to the question (Searle 1995a). The present paper makes a psychoanalytic contribution to this interdisciplinary effort and provides an alternative answer to the question, based on Freud's conceptualization of the problem of consciousness. The paper takes a concrete example from Searle's review, reanalyses it within Freud's metapsychological frame of reference, and shows how this frame provides a radical solution to the problem. This implication of Freud's work has not hitherto been recognized and so has not received the attention it deserves.

  10. Preserved consciousness in vegetative and minimal conscious states

    DEFF Research Database (Denmark)

    Kondziella, Daniel; Friberg, Christian K; Frokjaer, Vibe G;

    2016-01-01

    were insufficient for statistical evaluation. In conclusion, active paradigms may underestimate the degree of consciousness as compared to passive paradigms. While MCS patients show signs of preserved consciousness more frequently in both paradigms, roughly 15% of patients with a clinical diagnosis......Active, passive and resting state paradigms using functional MRI (fMRI) or EEG may reveal consciousness in the vegetative (VS) and the minimal conscious state (MCS). A meta-analysis was performed to assess the prevalence of preserved consciousness in VS and MCS as revealed by fMRI and EEG......, including command following (active paradigms), cortical functional connectivity elicited by external stimuli (passive paradigms) and default mode networks (resting state). Studies were selected from multiple indexing databases until February 2015 and evaluated using the Quality Assessment of Diagnostic...

  11. Consciousness: individuated information in action

    Directory of Open Access Journals (Sweden)

    Jakub Adam Jonkisz

    2015-07-01

    Full Text Available Within theoretical and empirical enquiries, many different meanings associated with consciousness have appeared, leaving the term itself quite vague. This makes formulating an abstract and unifying version of the concept of consciousness – the main aim of this article –into an urgent theoretical imperative. It is argued that consciousness, characterized as dually accessible (cognized from the inside and the outside, hierarchically referential (semantically ordered, bodily determined (embedded in the working structures of an organism or conscious system and useful in action (pragmatically functional, is a graded rather than an all-or-none phenomenon. A gradational approach, however, despite its explanatory advantages, can lead to some counterintuitive consequences and theoretical problems. In most such conceptions consciousness is extended globally (attached to primitive organisms or artificial systems, but also locally (connected to certain lower-level neuronal and bodily processes. For example, according to information integration theory (as introduced recently by Tononi and Koch, even such simple artificial systems as photodiodes possess miniscule amounts of consciousness. The major challenge for this article, then, is to establish reasonable, empirically justified constraints on how extended the range of a graded consciousness could be. It is argued that conscious systems are limited globally by the ability to individuate information (where individuated information is understood as evolutionarily embedded, socially altered and private, whereas local limitations should be determined on the basis of a hypothesis about the action-oriented nature of the processes that select states of consciousness. Using these constraints, an abstract concept of consciousness is arrived at, hopefully contributing to a more unified state of play within consciousness studies itself.

  12. Consciousness: individuated information in action.

    Science.gov (United States)

    Jonkisz, Jakub

    2015-01-01

    Within theoretical and empirical enquiries, many different meanings associated with consciousness have appeared, leaving the term itself quite vague. This makes formulating an abstract and unifying version of the concept of consciousness - the main aim of this article -into an urgent theoretical imperative. It is argued that consciousness, characterized as dually accessible (cognized from the inside and the outside), hierarchically referential (semantically ordered), bodily determined (embedded in the working structures of an organism or conscious system), and useful in action (pragmatically functional), is a graded rather than an all-or-none phenomenon. A gradational approach, however, despite its explanatory advantages, can lead to some counterintuitive consequences and theoretical problems. In most such conceptions consciousness is extended globally (attached to primitive organisms or artificial systems), but also locally (connected to certain lower-level neuronal and bodily processes). For example, according to information integration theory (as introduced recently by Tononi and Koch, 2014), even such simple artificial systems as photodiodes possess miniscule amounts of consciousness. The major challenge for this article, then, is to establish reasonable, empirically justified constraints on how extended the range of a graded consciousness could be. It is argued that conscious systems are limited globally by the ability to individuate information (where individuated information is understood as evolutionarily embedded, socially altered, and private), whereas local limitations should be determined on the basis of a hypothesis about the action-oriented nature of the processes that select states of consciousness. Using these constraints, an abstract concept of consciousness is arrived at, hopefully contributing to a more unified state of play within consciousness studies itself.

  13. Effects of high-sucrose feeding on insulin resistance and hemodynamic responses to insulin in spontaneously hypertensive rats.

    Science.gov (United States)

    Mélançon, Sébastien; Bachelard, Hélène; Badeau, Mylène; Bourgoin, Frédéric; Pitre, Maryse; Larivière, Richard; Nadeau, André

    2006-06-01

    This study was designed to investigate the effects of a sucrose diet on vascular and metabolic actions of insulin in spontaneously hypertensive rats (SHR). Male SHR were randomized to receive a sucrose or regular chow diet for 4 wk. Age-matched, chow-fed Wistar-Kyoto (WKY) rats were used as normotensive control. In a first series of experiments, the three groups of rats had pulsed Doppler flow probes and intravascular catheters implanted to determine blood pressure, heart rate, and blood flows. Insulin sensitivity was assessed during a euglycemic hyperinsulinemic clamp performed in conscious rats. In a second series of experiments, new groups of rats were used to examine glucose transport activity in isolated muscles and to determine endothelial nitric oxide synthase (eNOS) protein expression in muscles and endothelin content in vascular tissues. Sucrose feeding was shown to markedly enhance the pressor response to insulin and its hindquarter vasoconstrictor effect when compared with chow-fed SHR. A reduction in eNOS protein content in muscle, but no change in vascular endothelin-1 protein, was noted in sucrose-fed SHR when compared with WKY rats, but these changes were not different from those noted in chow-fed SHR. Similar reductions in insulin-stimulated glucose transport were observed in soleus muscles from both groups of SHR when compared with WKY rats. In extensor digitorum longus muscles, a significant reduction in insulin-stimulated glucose transport was only seen in sucrose-fed rats when compared with the other two groups. Environmental factors, that is, high intake of simple sugars, could possibly potentiate the genetic predisposition in SHR to endothelial dysfunction and insulin resistance.

  14. Familial history of hypertension as a predictor of increased arterial stiffness in normotensive offspring

    Directory of Open Access Journals (Sweden)

    Ghada Youssef

    2017-03-01

    Conclusion: The aortic and carotid stiffness parameters and SIDVP were higher in normotensive offspring of hypertensive parents. This finding could direct the attention towards the increased cardiovascular risk in this group and thus prompt earlier and tighter prevention of cardiovascular risk factors.

  15. Plasma prolactin, renin and catecholamines in young normotensive and borderline hypertensive subjects.

    Science.gov (United States)

    Saito, I; Takeshita, E; Saruta, T; Nagano, S; Sekihara, T

    1984-02-01

    It has been reported that patients with essential hypertension have high plasma prolactin levels and suggested that reduced central dopaminergic activity may be a factor in the pathogenesis of essential hypertension. This study examines the influence of posture on plasma prolactin, plasma catecholamines, plasma renin activity, blood pressure and heart rate in 24 patients with borderline hypertension (age 19 +/- 1 years) and 20 normotensive subjects matched for age and body mass index. Supine plasma prolactin levels were similar in both groups [borderline hypertension, 11.3 +/- 0.7 ng/ml; normotensive, 10.7 +/- 0.8 ng/ml (mean +/- s.e.m.)] and no increase in plasma prolactin was observed after 10 min standing in both groups. Normotensive and borderline hypertensive subjects had similar values for supine and upright plasma renin activity and plasma norepinephrine. There were no significant correlations between supine plasma prolactin and supine blood pressure, supine plasma renin activity or plasma norepinephrine when data from both normotensive and borderline hypertensive subjects were combined. These results may provide indirect evidence against the occurrence of reduced central dopaminergic activity in borderline hypertension.

  16. ENDOTHELIAL DYSFUNCTION IN YOUNG NORMOTENSIVE SUBJECTS WITH A FAMILY HISTORY OF ESSENTIAL HYPERTENSION

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective:To investigate whether endothelial dysfunction occurred in genetically vulnerable normotensive patients.Methods:Endothelial function was assessed by high-resolution vascular ultrasound.The diameter of brachial arteries were measured at rest.during reactive hyperemia and atfer sublingual nitroglycerine(GTN) in 70 young subjects with a mean age of 44.7(12.1 years:Among them,there were 30 patients with essential hypertension (group 1),20 normotensive patients with a family history of hypertension(group2)and 20 normotensive patients without a family history of cardiovascular diseases that served as controls(group3).Results:Flow-mediated dilatation of brachial arteries was significantly reduced in-roup 1and 2 when compared to group3(Group1:6.8(3.9vs group 2:8.0(3.6vs group3:13.2(5.9%,P<0.01).Conclusion:Endothelium-dependent vasodilatation was impaired in the young normotensive patients with a family history of hypertension.

  17. Oscillatory Correlates of Visual Consciousness

    Directory of Open Access Journals (Sweden)

    Stefano Gallotto

    2017-07-01

    Full Text Available Conscious experiences are linked to activity in our brain: the neural correlates of consciousness (NCC. Empirical research on these NCCs covers a wide range of brain activity signals, measures, and methodologies. In this paper, we focus on spontaneous brain oscillations; rhythmic fluctuations of neuronal (population activity which can be characterized by a range of parameters, such as frequency, amplitude (power, and phase. We provide an overview of oscillatory measures that appear to correlate with conscious perception. We also discuss how increasingly sophisticated techniques allow us to study the causal role of oscillatory activity in conscious perception (i.e., ‘entrainment’. This review of oscillatory correlates of consciousness suggests that, for example, activity in the alpha-band (7–13 Hz may index, or even causally support, conscious perception. But such results also showcase an increasingly acknowledged difficulty in NCC research; the challenge of separating neural activity necessary for conscious experience to arise (prerequisites from neural activity underlying the conscious experience itself (substrates or its results (consequences.

  18. Oscillatory Correlates of Visual Consciousness.

    Science.gov (United States)

    Gallotto, Stefano; Sack, Alexander T; Schuhmann, Teresa; de Graaf, Tom A

    2017-01-01

    Conscious experiences are linked to activity in our brain: the neural correlates of consciousness (NCC). Empirical research on these NCCs covers a wide range of brain activity signals, measures, and methodologies. In this paper, we focus on spontaneous brain oscillations; rhythmic fluctuations of neuronal (population) activity which can be characterized by a range of parameters, such as frequency, amplitude (power), and phase. We provide an overview of oscillatory measures that appear to correlate with conscious perception. We also discuss how increasingly sophisticated techniques allow us to study the causal role of oscillatory activity in conscious perception (i.e., 'entrainment'). This review of oscillatory correlates of consciousness suggests that, for example, activity in the alpha-band (7-13 Hz) may index, or even causally support, conscious perception. But such results also showcase an increasingly acknowledged difficulty in NCC research; the challenge of separating neural activity necessary for conscious experience to arise (prerequisites) from neural activity underlying the conscious experience itself (substrates) or its results (consequences).

  19. Female Consciousness in Jane Eyre

    Institute of Scientific and Technical Information of China (English)

    鲁存

    2014-01-01

    Charlotte Bront is a remarkable women writer in the 19th-century English literature. Jane Eyre received comprehensive attention. This thesis analyzes main characters from three aspects, Jane Eyre’s female consciousness, pursuit of equality, freedom and presents the limitation in Jane Eyre. It also examines the nature of Charlotte Bront?’s pioneering female consciousness and demonstrates its positive development.

  20. ELT and Consciousness-Raising

    Science.gov (United States)

    Al-Jardani, Khalid Salim Saif

    2012-01-01

    The paper highlights the concept of consciousness-raising. It relates it to different aspects of ELT such as explicit teaching, language awareness, language acquisition and practice. How these terms are related to the concept of consciousness-raising within the English Language teaching. Its main aim is to help learners to notice for themselves…

  1. The Emerging Physics of Consciousness

    CERN Document Server

    Tuszynski, Jack A

    2006-01-01

    Consciousness remains one of the major unsolved problems in science. How do the feelings and sensations making up conscious experience arise from the concerted actions of nerve cells and their associated synaptic and molecular processes? Can such feelings be explained by modern science, or is there an entirely different kind of explanation needed? And how can this seemingly intractable problem be approached experimentally? How do the operations of the conscious mind emerge out of the specific interactions involving billions of neurons? This book seeks answers to these questions on the underlying assumption that consciousness can be understood using the intellectual potential of modern physics and other sciences. There are a number of theories of consciousness, some based on classical physics while others require the use of quantum concepts. The latter ones have drawn criticism from the parts of the scientific establishment while simultaneously claiming that classical approaches are doomed to failure. The cont...

  2. Impact of Emotion on Consciousness

    DEFF Research Database (Denmark)

    Thomsen, Kristine Rømer; Lou, Hans Olav Christensen; Jønsson, Morten

    2011-01-01

    showed that participants were more confident and accurate when consciously seeing happy versus sad/neutral faces and words. When stimuli were presented subliminally, we found no effect of emotion. To investigate the neural basis of this impact of emotion, we recorded local field potentials (LFPs......) directly in the ACC in a chronic pain patient. Behavioural findings were replicated: the patient was more confident and accurate when (consciously) seeing happy versus sad faces, while no effect was seen in subliminal trials. Mirroring behavioural findings, we found significant differences in the LFPs...... after around 500 ms (lasting 30 ms) in conscious trials between happy and sad faces, while no effect was found in subliminal trials. We thus demonstrate a striking impact of emotion on conscious experience, with positive emotional stimuli enhancing conscious reportability. In line with previous studies...

  3. [The "bright spot of consciousness"].

    Science.gov (United States)

    Simonov, P V

    1990-01-01

    I.P. Pavlov considered consciousness as an area of optimum excitability moving over the human cerebral cortex depending on the character of performed mental activity. Contemporary methods of computer analysis of electrical activity and brain thermal production have allowed to turn this metaphor into experimentally observed reality. It is shown that preservation of connections of cortical gnostic zones with verbal structures of the left hemisphere is the obligatory condition for consciousness functioning. These data reinforce the determination of consciousness as operation with knowledge, which by means of words, mathematic symbols and art images can be transmitted to other people. Communicative origin of consciousness creates possibility of mental dialogue with oneself, i.e. leads to the appearance of self-consciousness of the personality.

  4. Conscience and consciousness: a definition.

    Science.gov (United States)

    Vithoulkas, G; Muresanu, D F

    2014-03-15

    While consciousness has been examined extensively in its different aspects, like in philosophy, psychiatry, neurophysiology, neuroplasticity, etc., conscience though it is an equal important aspect of the human existence, which remains an unknown to a great degree as an almost transcendental aspect of the human mind. It has not been examined as thoroughly as consciousness and largely remains a "terra incognita" for its neurophysiology, brain topography, etc. Conscience and consciousness are part of a system of information that governs our experience and decision making process. The intent of this paper is to define these terms, to discuss about consciousness from both neurological and quantum physics point of view, the relationship between the dynamics of consciousness and neuroplasticity and to highlight the relationship between conscience, stress and health.

  5. Declarative Consciousness for Reconstruction

    Science.gov (United States)

    Seymour, Leslie G.

    2013-12-01

    Existing information technology tools are harnessed and integrated to provide digital specification of human consciousness of individual persons. An incremental compilation technology is proposed as a transformation of LifeLog derived persona specifications into a Canonical representation of the neocortex architecture of the human brain. The primary purpose is to gain an understanding of the semantical allocation of the neocortex capacity. Novel neocortex content allocation simulators with browsers are proposed to experiment with various approaches of relieving the brain from overload conditions. An IT model of the neocortex is maintained, which is then updated each time new stimuli are received from the LifeLog data stream; new information is gained from brain signal measurements; and new functional dependencies are discovered between live persona consumed/produced signals

  6. Propranolol modifies platelet serotonergic mechanisms in rats.

    Science.gov (United States)

    Zółtowski, R; Pawlak, R; Matys, T; Pietraszek, M; Buczko, W

    2002-06-01

    Though the mechanisms for the vascular actions of vasodilatory beta-blockers are mostly determined, some of their interactions with monoaminergic systems are not elucidated. Because there are evidences supporting a possible involvement of serotonin (5-HT) in the actions of beta-blockers, we studied the effect of propranolol on peripheral serotonergic mechanisms in normotensive and Goldblatt two-kidney - one clip (2K1C) hypertensive rats. In both groups of animals propranolol decreased systolic blood pressure, significantly increased whole blood serotonin concentration and at the same time it decreased platelet serotonin level. The uptake of the amine by platelets from hypertensive animals was lower than that of normotensive animals and it was decreased by propranolol only in the latter. In both groups propranolol inhibited potentiation of ADP-induced platelet aggregation by serotonin. In conclusion, this study provides evidence that propranolol modifies platelet serotonergic mechanisms in normotensive and renal hypertensive rats.

  7. [Arterial rigidity and cardiovascular vagosympathetic activity in normotensive and hypertensive obese patients and type 2 diabetics].

    Science.gov (United States)

    Brahimi, M; Dabire, H; Platon, P; Hadj-Brahim, F; Attali, J R; Valensi, P

    2001-08-01

    An increase in arterial rigidity is associated with a poor cardiovascular prognosis. Several studies have suggested that an increase in sympathetic activity may be involved in essential hypertension. We have recently shown that vagal control of heart rate (HR) variations during standardised tests is altered in normotensive obese and diabetic patients. The aim of the present study was to compare cardiovascular vagosympathetic activity in obese and type 2 diabetic patients, either normotensive or hypertensive, and to investigate the relationship between pulse pressure (an index of arterial rigidity) and sympathetic activity in this population. Seventy normotensive obese and 32 mildly hypertensive obese patients, 18 normotensive type 2 diabetic patients and 14 mildly hypertensive type 2 diabetic patients were compared with 21 control subjects. Finapres studied HR and blood pressure variations. In the four groups, during a 6-min period at a controlled breathing rate, the high frequency peak of HR variations was significantly reduced (p < 0.001). The mid-frequency peak of systolic BP variations in the standing position, which depends on sympathetic activity, did not differ significantly between the four groups and control subjects. In obese and diabetic hypertensive patients, this peak correlated significantly with pulse pressure measured in the lying position (r = 0.379; p = 0.043 and r = 0.81; p < 0.0001, respectively). This study 1, confirms that vagal control of HR variations is reduced to a similar extent in obese and diabetic patients; and 2, suggests that cardiovascular sympathetic activity is relatively increased in these patients without significant difference between normotensive and hypertensive patients, but interestingly that the increase in arterial rigidity is associated with a higher sympathetic activity.

  8. What explains consciousness? Or…What consciousness explains?

    Science.gov (United States)

    Dulany, Donelson E

    2014-01-01

    In this invited commentary I focus on the topic addressed in three papers: De Sousa's (2013[1617]) Toward an Integrative Theory of Consciousness, a monograph with Parts 1 & 2, as well as commentaries by Pereira (2013a[59]) and Hirstein (2013[42]). All three are impressively scholarly and can stand-and shout-on their own. But theory of consciousness? My aim is to slice that topic into the two fundamentally different kinds of theories of consciousness, say what appears to be an ideology, out of behaviourism into cognitivism, now also influencing the quest for an "explanation of consciousness" in cognitive neuroscience. I will then say what can be expected given what we know of the complexity of brain structure, the richness of a conscious "vocabulary", and current technological limits of brain imaging. This will then turn to the strategy for examining "what consciousness explains"-metatheory, theories, mappings, and a methodology of competitive support, a methodology especially important where there are competing commitments. There are also increasingly common identifications of methodological bias in, along with failures to replicate, studies reporting unconscious controls in decision, social priming-as there have been in perception, learning, problem solving, etc. The literature critique has provided evidence taken as reducing, and in some cases eliminating, a role for conscious controls-a position consistent with that ideology out of behaviourism into cognitivism. It is an ideological position that fails to recognize the fundamental distinction between theoretical and metaphysical assertions.

  9. [Brain and consciousness].

    Science.gov (United States)

    Fernández de Molina, Antonio

    2002-01-01

    The philosophical and biological concepts of consciousness are briefly reviewed, from Aristoteles to Descartes to the modern neurobiologist of the last 15 years. The CRICK's corticothalamic integration view, the Edelman's primary and higher order consciousness concept as well as the Edelman and Tononi's dynamic core concept were discussed. Then the corticothalamic resonance theory by Llinás was reported. Central to Llinás's theory is the existence of electrical intrinsic properties of neurones in the central nervous system that allows them to oscillate at different frequencies and if the membrane properties are suitable also to resonate at specific frequencies. From this oscillation and the neuronal connectivity result the corticothalamic dynamic loops specific and non specific. The dynamic corticothalamic loop of the specific thalamic nuclei connect directly as well as through the inhibitory interneurones in layer 4, with the pyramids in layer 5 and 6. The pyramids's rhythmic discharge excite the thalamic specific neurones and indirectly through the reticular neurones a rebound burst is also generated in the specific relay neurones. The oscillatory properties of cortical inhibitory interneurones initiates the action of the recurrent circuit whose function is to inform the cerebral cortex of the content of the sensory pathways. On the other side, the thalamocortical resonant loops of the non especific nuclei, particularly the intralaminar, connect with theapical dendrites of layer 1 pyramids whose discharge go to the thalamic relay neurones directly and through the reticular nucleus. The clinical and MEG data are consistent with the suggestion that the intralaminar nucleus works as providing the binding signal to the sensory specif le information conveyed by the specific pathways. In this way the non specific corticothalamic loop would act as the conjunction mechanism along the dendritic apical shaft with the specific sensory information. The specific loop will

  10. Establishment of a telemetry model in conscious rats for evaluating the cardiovascular safety of AF114 injection%应用清醒大鼠遥测模型评价AF114注射液的心血管系统的安全性

    Institute of Scientific and Technical Information of China (English)

    袁海涛; 汪滢; 夏静; 刘刚; 彭双清

    2011-01-01

    目的:应用可在清醒自由活动状态下长期监测心血管系统参数和体温变化的大鼠遥测模型评价AF114注射液对心血管系统及体温的影响.方法:通过手术将可遥测大鼠血压、心电图、体温的植入体植入大鼠体内,建立清醒大鼠遥测模型.经颈静脉置入导管,经皮下穿刺将导管从颈后侧引出,固定,用于给药或采血.动物术后恢复1周,用阳性药物垂体后叶素验证模型的反应性.验证后用该模型评价AF114注射液对心血管系统及体温的影响.结果:32只大鼠手术后有29只恢复良好,无感染,均可监测到腹主动脉血压、心电图、体温等生理信号.经腹腔注射给予清醒大鼠垂体后叶素1 U·kg-1后,观察到平均动脉压升高,射血时间延长,体温降低,心率减慢.经静脉注射给予AF114注射液后,引起大鼠平均动脉压升高,心率加快,体温升高,对血小板计数和红细胞计数无明显影响.结论:清醒大鼠心血管遥测模型可用于长期、连续、动态监测心血管功能;静脉注射AF114注射液后可引起清醒大鼠血压升高、心率加快和体温升高.%Objective; To establish an animal model that can long-term monitor the cardiovascular parameters and body temperature in conscious and freely moving telemetry rats, and utilizing this model to evaluate the effects of AF114 injection on the cardiovascular parameters and body temperature. Methods; A transmitter body that can monitor BP, ECG, body temperature and activities was implanted in the cavity of the rats. A catheter was inserted in jugular vein for administration of saline and AF114 injection, or for collecting blood samples. After a week recovery, pituitary was used as a positive drug to test the reactivity of the telemetry rat model. Then we utilized this model to evaluate the effect of AF114 injection on the cardiovascular parameters and body temperature. Results; Of the 32 operated rats 29 rats recovered well, and their

  11. Electroacupuncture Delays Hypertension Development through Enhancing NO/NOS Activity in Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Hye Suk Hwang

    2011-01-01

    Full Text Available Using spontaneously hypertensive rats (SHR, this study investigated whether electroacupuncture (EA could reduce early stage hypertension by examining nitric oxide (NO levels in plasma and nitric oxide synthase (NOS levels in the mesenteric resistance artery. EA was applied to the acupuncture point Governor Vessel 20 (GV20 or to a non-acupuncture point in the tail twice weekly for 3 weeks under anesthesia. In conscious SHR and normotensive Wistar Kyoto (WKY rats, blood pressure was determined the day after EA treatment by the tail-cuff method. We measured plasma NO concentration, and evaluated endothelial NO syntheses (eNOS and neuronal NOS (nNOS protein expression in the mesenteric artery. Systolic blood pressure (SBP and diastolic blood pressure (DBP were lower after 3 weeks of GV20 treatment than EA at non-acupuncture point and no treatment control in SHR. nNOS expression by EA was significantly different between both WKY and no treatment SHR control, and EA at GV20 in SHR. eNOS expression was significantly high in EA at GV 20 compared with no treatment control. In conclusion, EA could attenuate the blood pressure elevation of SHR, along with enhancing NO/NOS activity in the mesenteric artery in SHR.

  12. Quantum-Holographic Informational Consciousness

    National Research Council Canada - National Science Library

    Francisco Di Biase

    2009-01-01

      The author propose a quantum-informational holographic model of brain-consciousness-universe interactions based in the holonomic neural networks of Karl Pribram, in the holographic quantum theory...

  13. Conscious brain, metacognition and schizophrenia.

    Science.gov (United States)

    Bob, Petr; Pec, Ondrej; Mishara, Aaron L; Touskova, Tereza; Lysaker, Paul H

    2016-07-01

    Recent findings indicate that the binding and synchronization of distributed neural activities are crucial for cognitive processes and consciousness. In addition, there is increasing evidence that disrupted feature binding is related to experiences of disintegration of consciousness in schizophrenia. These data suggest that the disrupted binding and disintegration of consciousness could be typically related to schizophrenia in terms of Bleuler's concept of "splitting". In this context, deficits in metacognitive capacity in schizophrenia may be conceptualized as a spectrum from more discrete to more synthetic activities, related to specific levels of neural binding and neurocognitive deficits. This review summarizes the recent research on metacognition and its relationship to deficits of conscious awareness that may be found in schizophrenia patients. Deficits in synthetic metacognition are likely linked to the integration of information during specific processes of neural binding. Those in turn may be related to a range of mental activities including reasoning style, learning potential and insight.

  14. Social Consciousness, Education and Transformative Activity

    Science.gov (United States)

    Pavlidis, Periklis

    2015-01-01

    This paper examines two aspects of social consciousness: consciousness in the sense of knowledge of the objective reality and consciousness in the sense of awareness of oneself as a subject in his/her social ties with other persons-subjects. In the light of such an approach to consciousness in this essay we discuss the importance of education and…

  15. Consciousness, Psychology, and Education: A Speculative Essay.

    Science.gov (United States)

    1980

    This monograph explores implications of the psychology of consciousness for education. The psychology of consciousness encompasses the relationships among behavior, experience, and states of consciousness. It is interpreted to include different states of consciousness, paranormal phenomena, mystical experiences, dreams, psychic healing, and other…

  16. Four-Dimensional Graded Consciousness.

    Science.gov (United States)

    Jonkisz, Jakub; Wierzchoń, Michał; Binder, Marek

    2017-01-01

    Both the multidimensional phenomenon and the polysemous notion of consciousness continue to prove resistant to consistent measurement and unambiguous definition. This is hardly surprising, given that there is no agreement even as regards the most fundamental issues they involve. One of the basic disagreements present in the continuing debate about consciousness pertains to its gradational nature. The general aim of this article is to show how consciousness might be graded and multidimensional at the same time. We therefore focus on the question of what it is, exactly, that is or could be graded in cases of consciousness, and how we can measure it. Ultimately, four different gradable aspects of consciousness will be described: quality, abstractness, complexity and usefulness, which belong to four different dimensions, these being understood, respectively, as phenomenal, semantic, physiological, and functional. Consequently, consciousness may be said to vary with respect to phenomenal quality, semantic abstraction, physiological complexity, and functional usefulness. It is hoped that such a four-dimensional approach will help to clarify and justify claims about the hierarchical nature of consciousness. The approach also proves explanatorily advantageous, as it enables us not only to draw attention to certain new and important differences in respect of subjective measures of awareness and to justify how a given creature may be ranked higher in one dimension of consciousness and lower in terms of another, but also allows for innovative explanations of a variety of well-known phenomena (amongst these, the interpretations of blindsight and locked-in syndrome will be briefly outlined here). Moreover, a 4D framework makes possible many predictions and hypotheses that may be experimentally tested (We point out a few such possibilities pertaining to interdimensional dependencies).

  17. Correlates of self-consciousness.

    Science.gov (United States)

    Turner, R G; Scheier, M F; Carver, C S; Ickes, W

    1978-06-01

    Examined the relationship between the three subscales of the Self-Consciousness Scale and a variety of other personality dimensions, including measures of reflectivity, self-regulation, and social desirability. Data from six geographically diverse samples (total N = 1395) were presented. In general, both the construct validity and discriminant validity of the subscales were supported. First, private self-consciousness significantly correlated with the Guilford-Zimmerman Thoughtfulness Scale and the Paivio Imagery Scale. Second, all of the self-consciousness subscales were shown to be relatively independent of the social desirability response set. Third, less than 6% of the variance in each self-consciousness subscale was shared with scores on the Self-Monitoring Scale. Finally, the minimal relationships between the self-consciousness subscales and measures of emotionality and test anxiety reported by Carver and Glass (1976) were in general replicated. The low magnitude of the correlations obtained was interpreted as supporting the distinctive contribution of the Self-Consciousness Scale to personality assessment.

  18. Esteróide anabolizante inibe a angiogênese induzida pelo treinamento físico de natação em músculo sóleo de ratos normotensos Anabolic steroid impairs the angiogenesis induced by swimming training in soleus muscle of normotensive rats

    Directory of Open Access Journals (Sweden)

    Ursula Paula Reno Soci

    2009-09-01

    damaging. To study the effects of EAA on the cardiovascular system, Wistar rats were randomized into Sedentary Control (SC, Sedentary Steroid (SA, Trained Control (TC and Trained Steroid (TA groups. We evaluated the effects of swimming training (60min/day, 5x/week during 10 week and AAS (nandrolone decanoate - 5 mg/kg sc, 2x/week on cardiac output, basal blood flow (Qb, DC basal and after injection of a vasodilator to observe the endothelium dependent vasodilatation (acetylcholine - Q Ach(Q Ach, DC Ach, capillary to fiber ratio (r c/f and vascular-endothelial growth factor expression (VEGF in soleus muscle (oxidative fibers. Serum testosterone increased in SA and TA. Exercise training significantly decreased resting heart rate. Qb was not different among groups, and QAch was higher in TC group, however in TA group this beneficial effect of swimming exercise training was lost by association with EAA. Rc/f and VEGF were higher only in TC group. These results suggest that swimming training associated with EAA inhibit angiogenesis and arteriogenesis observed as effects of aerobic training, and impairs the red skeletal muscle blood flow which predispose physically active AAS users to vascular diseases.

  19. Effect of losartan on microalbuminuria in normotensive patients with type 2 diabetes mellitus. A randomized clinical trial

    NARCIS (Netherlands)

    A.A.M. Zandbergen (Adrienne); M.G.A. Baggen (Marinus); S.W.J. Lamberts (Steven); A.H. Bootsma (Aart); D. de Zeeuw (Dick); R.J.T. Ouwendijk (Rob)

    2003-01-01

    textabstractBACKGROUND: Angiotensin-converting enzyme inhibitors have shown antiproteinuric effects in normotensive and hypertensive diabetic patients. Angiotensin-receptor antagonists reduce urinary albumin excretion and the risk for renal and cardiovascular complications in

  20. Effect of losartan on microalbuminuria in normotensive patients with type 2 diabetes mellitus - A randomized clinical trial

    NARCIS (Netherlands)

    Zandbergen, AAM; Baggen, MGA; Bootsma, AH; de Zeeuw, D; Ouwendijk, RJT; LAMBERTS, SWJ

    2003-01-01

    Background: Angiotensin-converting enzyme inhibitors have shown antiproteinuric effects in normotensive and hypertensive diabetic patients. Angiotensin-receptor antagonists reduce urinary albumin excretion and the risk for renal and cardiovascular complications in hypertensive patients with type 2 d

  1. Effect of losartan on microalbuminuria in normotensive patients with type 2 diabetes mellitus - A randomized clinical trial

    NARCIS (Netherlands)

    Zandbergen, AAM; Baggen, MGA; Bootsma, AH; de Zeeuw, D; Ouwendijk, RJT; LAMBERTS, SWJ

    2003-01-01

    Background: Angiotensin-converting enzyme inhibitors have shown antiproteinuric effects in normotensive and hypertensive diabetic patients. Angiotensin-receptor antagonists reduce urinary albumin excretion and the risk for renal and cardiovascular complications in hypertensive patients with type 2 d

  2. COMPARISON OF COGULATION PROFILE IN PRE ECLAMPTIC AND ECLAMPTIC PATIENTS WITH NORMOTENSIVE PREGNANT PATIENTS

    Directory of Open Access Journals (Sweden)

    Priyanka

    2014-03-01

    Full Text Available AIM: To compare the coagulation parameters in patients with preeclampsia and eclampsia with normotensive pregnant patients in Nainital district of Uttarakhand state. MATERIAL AND METHODS: From January 2012 to June 2013, coagulation indices including platelet count, prothrombin time (PT, activated partial thromboplastin time (aPTT, bleeding time (BT and clotting time (CT were measured in 100 patients with preeclampsia and eclampsia and compared with 100 normotensive pregnant women. The patients with coagulopathies were excluded. RESULT: In pre-eclampsia and eclampsia, decrease in platelet count (157.18±56.66 lacs/cumm was highly significant (p<0.001. PT, aPTT and CT were normal but BT (322.46±171.39 sec was significantly prolonged (p<0.001 in pre eclampsia and eclampsia patients. CONCLUSION: The abnormalities pertaining to coagulation parameters in hypertensive disorders of pregnancy indicate the intravascular coagulation.

  3. Increased left ventricular mass in normotensive type 1 diabetic patients with diabetic nephropathy

    DEFF Research Database (Denmark)

    Sato, A; Tarnow, L; Parving, H H

    1998-01-01

    OBJECTIVE: Diabetic nephropathy increases the risk of premature cardiovascular disease and sudden death, particularly in type 1 diabetic patients. One possible mechanism for this risk may be left ventricular hypertrophy. In our study, we aimed to evaluate left ventricular structure and function...... to the increased cardiac morbidity and mortality in normotensive type 1 diabetic patients with diabetic nephropathy. Glycemic abnormalities and activation of the renin-angiotensin system may lead to the ventricular enlargement....

  4. Severe normotensive metabolic alkalosis in a 2-month-old boy with hyperekplexia.

    Science.gov (United States)

    Schlapbach, L J; Sozzo, A; Ramelli, G; Bianchetti, M G

    2006-02-01

    A 2-month-old infant with hereditary hyperekplexia, umbilical and bilateral inguinal hernias and history of poor feeding was noted to have severe normotensive metabolic alkalosis: sodium 132 mmol/L, potassium 3.4 mmol/L, chloride 77 mmol/L, pH 7.55, carbon dioxide tension 56.3 mmHg and bicarbonate 48.0 mmol/L. After parenteral rehydration and treatment with clonazepam, laboratory parameters normalized.

  5. The presence of consciousness in absence seizures.

    Science.gov (United States)

    Bayne, Tim

    2011-01-01

    This paper examines three respects in which the study of epileptic absence seizures promises to inform our understanding of consciousness. Firstly, it has the potential to bear on debates concerning the behavioural and cognitive functions associated with consciousness. Secondly, it has the potential to illuminate the relationship between background states (or 'levels') of consciousness and the contents of consciousness. Thirdly, it has the potential to bear on our understanding of the unity of consciousness.

  6. Mind-brain and consciousness in psychoanalysis.

    Science.gov (United States)

    Meissner, W W

    2008-01-01

    Understanding how the brain produces conscious mentation is vital to the prospective integration of psychoanalytic and neuroscientific study of the mind-brain relation. This essay explores some of the current opinions, based on recent neuroscientific research, regarding origins of consciousness in the brain. Areas explored include levels of consciousness, waking versus dream consciousness, and issues of consciousness and self-organization in split-brain studies. Some tentative suggestions are made regarding clinical implications of this perspective.

  7. Changes in serum aldosterone are associated with changes in obesity-related factors in normotensive overweight and obese young adults

    OpenAIRE

    2013-01-01

    Recent data suggest excess circulating aldosterone promotes cardiometabolic decline. Weight loss may lower aldosterone levels, but little longitudinal data is available in normotensive adults. We aimed to determine if, independent of changes in sodium excretion, reductions in serum aldosterone are associated with favorable changes in obesity-related factors in normotensive overweight/obese young adults. We studied 285 overweight/obese young adult participants (body mass index (BMI) ≥ 25 and <...

  8. Is nail fold capillaroscopy useful in normotensive and primary open angle glaucoma? A pilot study.

    Science.gov (United States)

    Božić, Marija; Senćanić, Paraskeva-Hentova; Spahić, Goran; Kontić, Dorđe; Marković, Vujica; Marjanović, Ivan; Stojkovic, Milenko; Dorđević-Jocić, Jasmina

    2010-12-01

    Vascular dysregulation is deemed a significant risk factor in glaucoma occurrence and progression. Capillaroscopy of the blood vessels on the finger nail-fold is a method that can provide information regarding the state of the vascular system at the capillary level. The aim of this pilot study was to determine whether there are significant differences in the morphological characteristics of the peripheral blood vessels in normotensive glaucoma and primary open angle glaucoma. An ophthalmological and capillaroscopic examination was conducted on 30 normotensive glaucoma patients and 30 primary open angle glaucoma patients. The capillaroscopic characteristics described were as follows: capillary row density, capillary diameter, number of spirally formed capillaries, permeability of the loop, and loop resistance. Statistically, significantly more intensively spiraled capillaries were found in normotensive glaucoma patients (χ(2) test, p < 0.05). Results confirm the thesis that vascular factors play a significant role in the pathogenesis of the glaucoma, especially in cases where the level of intraocular pressure cannot be deemed responsible for the present damage of the optical nerve. Despite the newer, technologically more developed methods for diagnostics and monitoring glaucoma, it is often not easy to establish the right diagnosis and determine further the course of the illness, since the role the intraocular pressure (IOP) plays compared to the role of vascular factors is unknown; hence, capillaroscopy as a complementary diagnostic procedure can be of help.

  9. Correlation between the levels of circulating adhesion molecules and atherosclerosis in type-2 diabetic normotensive patients

    Science.gov (United States)

    Vargas-Robles, Hilda; Serrano, Alberto Maceda; Lozano-Nuevo, Jose Juan; Escalante-Acosta, Bruno Alfonso

    2009-01-01

    Endothelial dysfunction is a common feature in type-2 diabetic patients and is associated with inflammation, increased levels of circulating soluble adhesion molecules and atherosclerosis. The aim of this study was to evaluate the relationship between the levels of circulating soluble adhesion molecules and the degree of atherosclerosis in normotensive type-2 diabetic patients. Results: We found significant correlations between ICAM-1 (r = 0.69, p < 0.001 95% IC 0.65 to 0.82) and VCAM-1 (r = 0.4, p < 0.03, 95% IC 0.65 to 0.82) levels and maximal carotid artery intimal-medial thickness, whereas no correlation was observed with E-selectin. Methods: We studied 30 normotensive type-2 diabetic patients in whom VCAM-1, ICAM-1 and E-selectin were measured by ELISA. Additionally, the intimal-medial thickness of both the common and internal carotid arteries was measured (B-mode ultrasound). The levels of circulating adhesion molecules and maximal carotid artery intimal-medial thicknesses were correlated using the Spearman correlation coefficient test. Statistical analysis was performed with ANOVA. Conclusion: Our results suggest that ICAM-1 and VCAM-1 are markers associated, and correlated with the degree of atherosclerosis in normotensive type-2 diabetic patients. PMID:19717975

  10. A comparision between Plasma lipids concentration in preeclamptic and normotensive women

    Directory of Open Access Journals (Sweden)

    F.Vasheqani

    2006-01-01

    Full Text Available Background and purpose : Pregnancy may cause hypertension in normotensive women or aggrevate preexisting hypertention. The incidence of Preeclamsia is 5-10%, and is an important contributor to maternal and fetal mortality and morbidity. According to many predisposing factors in pathophysiology of preeclampsia, the role of lipid preoxides, is also important. In this study attempts are made to show the relationship between inceasing of plasma lipids and hypertension in pregnancy.Materials and Methods : This is a case-control study on pregnant women reffering to Sari Imam Khomeini Hospital, From Oct. 2003 to Oct. 2004. Case group include 100 preeclamptic pregnant women and for control group 100 normotensive pregnant women were recruired. (preeclamsia : BP> = 140 /90 mmHg, or Proteinuria > + 1 0r > = 300mg/dL in urine 24 h .Total TG, cholestrol, HDL and LDL were measured by enzymatic methods. Statistical analysis were performed using T-Test and Pearson's method.Results : The most important results are as follows: The mean of TG in case group was 45 % more than that of the control group (P<0.001, sig. The mean of cholestrol level in case group was 15 % more than control group (P<0.01, sig. The mean of LDL in case group is 5 % more than that of the control group (NS.Conclusion : As the levels of plasma lipids in preeclamptic women were more than normotensive women; measuring of Plasma lipids also can be a marker for predisposing to Preeclampsia.

  11. Acute effect of resistance exercise performed at different intensities on the hemodynamics of normotensive men

    Directory of Open Access Journals (Sweden)

    Mauricio Assis Saldanha

    2016-06-01

    Full Text Available The aim of this study was to investigate the acute effect of resistance exercise performed at different intensities on the hemodynamics of normotensive men. The study included 10 normotensive and recreationally-trained men (25.40 ± 6.90 years performed the following three experimental protocols in a randomized order: a 60% of 8RM; b 80% of 8RM; c 100% of 8RM. All protocols performed six exercises (Leg Press, Vertical Bench Press, Leg Flexion, Close-Grip Seated Row, Leg Extension and Shoulder Press with three sets of eight repetitions for each exercise. Systolic blood pressure (SBP, diastolic blood pressure (DBP, heart rate (HR and double product (DP were measured at rest, at the end of exercise and during the 60-minute post-exercise. The findings showed that there was a significant reduction in the faster SBP with a longer duration (p 0.05. There were significantly higher elevations in HR and DP for 100% of 8RM at all times (p<0.0001. We conclude that high intensities (100% of 8RM promote post-exercise hypotension with faster responses and greater duration and increase HR and DP in normotensive men.

  12. [Relationship between vasosympathetic activity and insulin resistance in normotensive and mildly hypertensive obese patients].

    Science.gov (United States)

    Valensi, P; Dabire, H; Brahimi, M; Paries, J; Platon, P; Attali, J R

    2001-08-01

    Several studies have well demonstrated that obesity is associated with changes in cardiovascular vagosympathetic activity. The aim of the present work was to evaluate this activity in normotensive and in mildly hypertensive obese patients, and to correlate this activity with clinical and biological indexes of insulin resistance. Heart rate (HR) and systolic blood pressure (sBP) were examined by spectral analysis in 70 normotensive obese patients (group 1), 32 mildly hypertensive obese patients (group 2), and 21 controls. The high frequency peak of HR variations at a controlled breathing rate (vagal activity) was significantly reduced in both groups (p < 0.001). The mid frequency peak of sBP in the standing position (sympathetic activity) was similar in both groups and in the control group. In groups 1 and 2, the high frequency peak correlated negatively with age (p = 0.005 and 0.034 respectively). In group 1, the mid frequency peak correlated positively with fat mass, fasting plasma insulin and triglyceride levels, and insulin resistance index (p < or = 0.03). In group 2, the mid frequency peak correlated positively with fasting insulin and insulin resistance index (p = 0.006 and 0.007 respectively). This study shows that, in obese patients: 1. cardiac vagal activity is reduced in normotensive and mildly hypertensive subjects; 2. vascular sympathetic activity is unchanged in means but may be increased as a consequence of adiposity, hyperinsulinemia and insulin resistance, and this increase is likely to be involved in the increase of blood pressure.

  13. Cortisol awakening response and cognitive performance in hypertensive and normotensive older people.

    Science.gov (United States)

    Pulopulos, Matias M; Hidalgo, Vanesa; Puig-Perez, Sara; Salvador, Alicia

    2016-07-01

    Healthy older people with a cortisol awakening response (CAR) of decreased magnitude show worse frontal cortex-related cognitive performance. Systemic hypertension has been related to a CAR of decreased magnitude. Additionally, worse executive function and processing speed have been observed in older people with systemic hypertension. This is the first study to examine the relationship between the CAR (measured with six saliva samples at home on two consecutive weekdays) and cognitive performance, in both hypertensive (n=26) and normotensive (n=28) older people (from 56 to 78years old). Hypertensive participants showed lower morning cortisol secretion, and they also woke up earlier. No differences in CAR were observed. A CAR of decreased magnitude was related to worse executive function in both hypertensive and normotensive participants, but to slower processing speed only in normotensive participants. Being treated with antihypertensive for a longer period of time was related to a CAR of increased magnitude and better performance on executive function. Our findings suggest that earlier awakening time in hypertensive older people might underlie the lower overall morning cortisol secretion observed in previous studies. Additionally, this study confirms that a dysregulation of the CAR is related to worse executive function, and it extends this association to hypertensive older people. Finally, it is worth noting that hypertension may moderate the relationship between CAR and processing speed.

  14. Effect of amlodipine on renin secretion and renin gene expression in rats.

    OpenAIRE

    Schricker, K.; Hamann, M.; Macher, A.; Krämer, B. K.; Kaissling, B; Kurtz, A.

    1996-01-01

    1. This study was done to characterize the influence of calcium channel blockade on renin secretion and renin gene expression in normal rats and rats with renovascular hypertension. To this end we studied the effects of the 1,4-dihydropyridine derivative, amlodipine, on plasma renin activity and renal renin m-RNA levels in normal rats and rats with unilateral renal hypoperfusion induced by applying 0.2 mm left renal artery clips over four days. 2. In normotensive rats, amlodipine significantl...

  15. Proposal for an Approach to Artificial Consciousness Based on Self-Consciousness

    OpenAIRE

    Menant, Mr Christophe

    2007-01-01

    Current research on artificial consciousness is focused on phenomenal consciousness and on functional consciousness. We propose to shift the focus to self-consciousness in order to open new areas of investigation. We use an existing scenario where self-consciousness is considered as the result of an evolution of representations. Application of the scenario to the possible build up of a conscious robot also introduces questions relative to emotions in robots. Areas of investigation...

  16. Edmund Husserl's theory of image consciousness, aesthetic consciousness, and art

    OpenAIRE

    2014-01-01

    The central theme of my dissertation is Husserl’s phenomenological analysis of how we experience images. The aim of my dissertation is twofold: 1) to offer a contribution to the understanding of Husserl’s theory of image consciousness, aesthetic consciousness and art, and 2) to find out whether Husserl’s theory of the experience of images is applicable to modern and contemporary art, particularly to strongly site-specific art, unaided ready-mades, and contemporary films and theatre plays in w...

  17. Consciousness is still in business.

    Science.gov (United States)

    Guterman, Yossi

    2010-06-01

    In a recent study (Hassin, Bargh, Engell, & McCulloch, 2009, Exp. 4) half of the participants were informed ofthe occasional occurrence of location regularities (patterns) in visual stimulus sets, while the other half was not. Evidence was presented to the effect that uninformed participants extracted the patterns from the displays better than the informed participants. The authors interpret their finding as demonstrating that working memory (WM) can operate non-consciously. However, inspection of the data suggests that rather than being more effective than the informed participants in extracting patterns, uninformed participants were more strongly affected by the "Broken Patterns" that served as misleading cues. Thus whereas the findings may support the possibility of non-conscious operation of low level WM functions, they nevertheless underscore the importance of conscious awareness as far as higher level functions are concerned. 2010 Elsevier Inc. All rights reserved.

  18. How to Assess Ictal Consciousness?

    Directory of Open Access Journals (Sweden)

    Mirja Johanson

    2011-01-01

    Full Text Available Despite the complexity and methodological difficulties in defining the concept of consciousness, it is a central concept in epileptology, and should thus be tractable for scientific analysis. In the present article, a two-dimensional model consisting of concepts related to the level and the contents of consciousness will be presented. This model has been found to be well suited for the description of seizure-induced alterations of consciousness, and is supported both by findings from neuroimaging and electrophysiological studies as well as from phenomenological studies. Further, we will review both traditional introspective methods as well as methods that have recently been developed or utilized in epilepsy research, summarize the main findings concerning first person experiences during epileptic seizures acquired with some of these methods, and discuss their strengths and weaknesses.

  19. Paranoia and self-consciousness.

    Science.gov (United States)

    Fenigstein, A; Vanable, P A

    1992-01-01

    A new instrument designed to assess paranoid thought in college students, together with reliability and validity data, was presented in Study 1. A single general factor accounted for a substantial portion of the variance in the full scale. Public self-consciousness was consistently and significantly correlated with the present measure of paranoia. In Study 2, both pretested paranoia and public self-consciousness were related to feelings of being watched (a classical manifestation of paranoia), although public self-consciousness had an effect only when there was a 2-way mirror present. In Study 3, self-attention, experimentally induced using a story construction task, again resulted in a heightened sense of being observed. Discussion focuses on paranoid cognition as characteristic of everyday thought and the implications of self-attention for social perception processes.

  20. Consciousness, biology and quantum hypotheses

    Science.gov (United States)

    Baars, Bernard J.; Edelman, David B.

    2012-09-01

    Natural phenomena are reducible to quantum events in principle, but quantum mechanics does not always provide the best level of analysis. The many-body problem, chaotic avalanches, materials properties, biological organisms, and weather systems are better addressed at higher levels. Animals are highly organized, goal-directed, adaptive, selectionist, information-preserving, functionally redundant, multicellular, quasi-autonomous, highly mobile, reproducing, dissipative systems that conserve many fundamental features over remarkably long periods of time at the species level. Animal brains consist of massive, layered networks of specialized signaling cells with 10,000 communication points per cell, and interacting up to 1000 Hz. Neurons begin to divide and differentiate very early in gestation, and continue to develop until middle age. Waking brains operate far from thermodynamic equilibrium under delicate homeostatic control, making them extremely sensitive to a range of physical and chemical stimuli, highly adaptive, and able to produce a remarkable range of goal-relevant actions. Consciousness is “a difference that makes a difference” at the level of massive neuronal interactions in the most parallel-interactive anatomical structure of the mammalian brain, the cortico-thalamic (C-T) system. Other brain structures are not established to result in direct conscious experiences, at least in humans. However, indirect extra-cortical influences on the C-T system are pervasive. Learning, brain plasticity and major life adaptations may require conscious cognition. While brains evolved over hundreds of millions of years, and individual brains grow over months, years and decades, conscious events appear to have a duty cycle of ∼100 ms, fading after a few seconds. They can of course be refreshed by inner rehearsal, re-visualization, or attending to recurrent stimulus sources. These very distinctive brain events are needed when animals seek out and cope with new

  1. Neural correlates of consciousness reconsidered.

    Science.gov (United States)

    Neisser, Joseph

    2012-06-01

    It is widely accepted among philosophers that neuroscientists are conducting a search for the neural correlates of consciousness, or NCC. Chalmers (2000) conceptualized this research program as the attempt to correlate the contents of conscious experience with the contents of representations in specific neural populations. A notable claim on behalf of this interpretation is that the neutral language of "correlates" frees us from philosophical disputes over the mind/body relation, allowing the science to move independently. But the experimental paradigms and explanatory canons of neuroscience are not neutral about the mechanical relation between consciousness and the brain. I argue that NCC research is best characterized as an attempt to locate a causally relevant neural mechanism and not as an effort to identify a discrete neural representation, the content of which correlates with some actual experience. It might be said that the first C in "NCC" should stand for "causes" rather than "correlates."

  2. Reading embodied consciousness in "Emma".

    Science.gov (United States)

    Harbus, Antonina

    2011-01-01

    The language of Emma (1815) reflects Jane Austen's developing view of embodied consciousness and her particular interest in this novel in the physical manifestations of emotions, such as blushes and nervous responses. The discursive exploration of the inner life in Emma is the product of a cultural context that features emerging brain science and Austen's own conceptualization of the psychophysical nature of emotions. This article analyzes the language of mind and emotion in Emma, to contend that Austen grapples with the implications of the idea of embodied consciousness in a narrative that contrasts mind reading with interpreting the body.

  3. Streptozotocin induced diabetes in lyon hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    LeaEMONNOT; JeanSASSARD; MingLO

    2004-01-01

    AIM: Lyon hypertensive (LH) rats, compared to their normotensive controls (LL) exhibit an increased blood pressure (BP)associated with a marked proteinuria and a metabolic syndrom including elevated plasma lipids and insulin/glucose ratio. The aim of the present work was to determine wether a type 2 diabetes could be induced in LH rats so as to obtain a model suitable for study of the relationships between diabetes and hypertension.

  4. Dynamics of TGF-initiated nephron-nephron interactions in normotensive rats and SHR

    DEFF Research Database (Denmark)

    Yip, K P; Holstein-Rathlou, N H; Marsh, D J

    1992-01-01

    interactions between nephrons in these dynamics, we measured tubular pressure simultaneously in two or more nephrons. The oscillations were synchronized in nephrons supplied by a common cortical radial artery. The correlation coefficient of pressure records from coupled nephrons was 0.86 +/- 0.02. Intratubular...... nephron had no effect on adjacent but noncoupled nephrons. In SHR, the correlation coefficient of tubular pressure records was high from coupled nephrons only; furosemide diminished the autospectral power of pressure fluctuations to approximately 60-75% of control in both perfused and coupled nephrons...

  5. Vascular Response of Ruthenium Tetraamines in Aortic Ring from Normotensive Rats

    Directory of Open Access Journals (Sweden)

    Ana Gabriela Conceição-Vertamatti

    2015-03-01

    Full Text Available Background: Ruthenium (Ru tetraamines are being increasingly used as nitric oxide (NO carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. Objective: To evaluate the vascular response of the tetraamines trans-[RuII(NH34(Py(NO]3+, trans-[RuII(Cl(NO (cyclan](PF62, and trans-[RuII(NH34(4-acPy(NO]3+. Methods: Aortic rings were contracted with noradrenaline (10−6 M. After voltage stabilization, a single concentration (10−6 M of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10−6 M and sodium nitroprusside at 10−6 M as well as by histological examination. Results: Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. Conclusion: The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10−6 M at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used in the formulation of the compound.

  6. Vascular Response of Ruthenium Tetraamines in Aortic Ring from Normotensive Rats

    Energy Technology Data Exchange (ETDEWEB)

    Conceição-Vertamatti, Ana Gabriela; Ramos, Luiz Alberto Ferreira [Universidade Estadual de Campinas (UNICAMP), São Paulo, SP (Brazil); Calandreli, Ivy; Chiba, Aline Nunes [Universidade de São Paulo (USP), Campus Ribeirão Preto, São Paulo, SP (Brazil); Franco, Douglas Wagner [Universidade de São Paulo (USP), Campus São Carlos, São Paulo, SP (Brazil); Tfouni, Elia [Universidade de São Paulo (USP), Campus Ribeirão Preto, São Paulo, SP (Brazil); Grassi-Kassisse, Dora Maria, E-mail: doramgk@unicamp.br [Universidade Estadual de Campinas (UNICAMP), São Paulo, SP (Brazil)

    2015-03-15

    Ruthenium (Ru) tetraamines are being increasingly used as nitric oxide (NO) carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. To evaluate the vascular response of the tetraamines trans-[Ru{sup II}(NH{sub 3}){sub 4}(Py)(NO)]{sup 3+}, trans-[Ru{sup II}(Cl)(NO) (cyclan)](PF{sub 6}){sub 2}, and trans-[Ru{sup II}(NH{sub 3}){sub 4}(4-acPy)(NO)]{sup 3+}. Aortic rings were contracted with noradrenaline (10{sup −6} M). After voltage stabilization, a single concentration (10{sup −6} M) of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10{sup −6} M and sodium nitroprusside at 10{sup −6} M as well as by histological examination. Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10{sup −6} M) at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used in the formulation of the compound.

  7. Renoprotective effects of VPI versus ACEI in normotensive nephrotic rats on different sodium intakes

    NARCIS (Netherlands)

    Laverman, GD; Van Goor, H; Henning, RH; De Jong, PE; De Zeeuw, D; Navis, G

    2003-01-01

    Background. Control of blood pressure (BP) and optimal reduction of proteinuria (U-prot ) are necessary for long-term renoprotection. Unfortunately, angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II (Ang II) antagonists are not effective during sodium repletion. Vasopeptidase inhibi

  8. Impact of gonadectomy on sympatho-vagal balance in male and female normotensive rat

    NARCIS (Netherlands)

    Pijacka, Wioletta; Clifford, Bethan; Walas, Dawid; Tilburgs, Chantal; Joles, Jaap A; McMullen, Sarah; Langley-Evans, Simon C

    OBJECTIVE: It is well established that autonomic nervous system and sympatho-vagal balance plays an important role in maintaining arterial blood pressure (ABP) (Salman IM., 2016) and that autonomic regulation of ABP differs between males and females (Hart EC et al., 2014). We hypothesised that sex

  9. Different patterns of H2S/NO activity and cross-talk in the control of the coronary vascular bed under normotensive or hypertensive conditions.

    Science.gov (United States)

    Testai, L; D'Antongiovanni, V; Piano, I; Martelli, A; Citi, V; Duranti, E; Virdis, A; Blandizzi, C; Gargini, C; Breschi, M C; Calderone, V

    2015-05-01

    Hydrogen sulfide (H2S) and nitric oxide (NO) play pivotal roles in the cardiovascular system. Conflicting results have been reported about their cross-talk. This study investigated their interplays in coronary bed of normotensive (NTRs) and spontaneously hypertensive rats (SHRs). The effects of H2S- (NaHS) and NO-donors (sodium nitroprusside, SNP) on coronary flow (CF) were measured in Langendorff-perfused hearts of NTRs and SHRs, in the absence or in the presence of propargylglycine (PAG, inhibitor of H2S biosynthesis), L-NAME (inhibitor of NO biosynthesis), ODQ (inhibitor of guanylate cyclase), L-Cysteine (substrate for H2S biosynthesis) or L-Arginine (substrate for NO biosynthesis). In NTRs, NaHS and SNP increased CF; their effects were particularly evident in Angiotensin II (AngII)-contracted coronary arteries. The dilatory effects of NaHS were abolished by L-NAME and ODQ; conversely, PAG abolished the effects of SNP. In SHRs, high levels of myocardial ROS production were observed. NaHS and SNP did not reduce the oxidative stress, but produced clear increases of the basal CF. In contrast, in AngII-contracted coronary arteries of SHRs, significant hyporeactivity to NaHS and SNP was observed. In SHRs, the vasodilatory effects of NaHS were only modestly affected by L-NAME and ODQ; PAG poorly influenced the effects of SNP. Then, in NTRs, the vascular actions of H2S required NO and vice versa. By contrast, in SHRs, the H2S-induced actions scarcely depend on NO release; as well, the NO effects are largely H2S-independent. These results represent the first step for understanding pathophysiological mechanisms of NO/H2S interplays under both normotensive and hypertensive conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Relationships between use of statins and arterial stiffness in normotensive and hypertensive patients with coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-guang; CHEN Bing-wei; L(U) Na-qiang; CHENG Yan-mei; DANG Ai-min

    2013-01-01

    Background Statins improve arterial stiffness in patients with coronary artery disease (CAD).Hypertension is a predominant contributor of arterial stiffening.However,the influence of hypertension on the effect of statins for improving arterial stiffness in CAD patients has seldom been investigated.Therefore,in this study,we investigated the relationships between statin use and arterial stiffness in normotensive and hypertensive CAD patients.Methods Brachial-ankle pulse wave velocity (ba-PWV) was measured in 437 patients,including 220 hypertensive CAD patients (121 used statins,99 did not) and 217 normotensive CAD patients (105 used statins,112 did not).The normotensive and hypertensive CAD patients were matched according to age,sex,and body mass index (BMI).Results In the normotensive and hypertensive CAD patients,lipid profiles were significantly improved in the statin group compared with the non-statin group.No significant differences in the administered statins (i.e.,atorvastatin,simvastatin,rosuvastatin,and pravastatin) and statin therapy duration were found between normotensive and hypertensive CAD patients (all P>0.05).No significant correlation of ba-PWV and statin therapy duration was found in all CAD patients,normotensive CAD patients,or hypertensive CAD patients (all P>0.05).ba-PWV in the statin group was significantly lower than that in the non-statin group in normotensive CAD patients ((1331.68±167.52) cm/s vs.(1468.61±244.54) cm/s,P=0.002) but not in hypertensive CAD patients (P>0.05).In multiple linear regression analyses,statin therapy was significantly associated with ba-PWV after adjusting for confounding variables in normotensive CAD patients (P=0.018) but not in hypertensive CAD patients (P>0.05).Conclusions Statins may significantly improve arterial stiffness in CAD patients,and hypertension may probably influence the effectiveness of statin therapy in improving arterial stiffness in this population.Further studies are required to

  11. Perinatal L-arginine and antioxidant supplements reduce adult blood pressure in spontaneously hypertensive rats

    NARCIS (Netherlands)

    Racasan, S; Braam, B; van der Giezen, DM; Goldschmeding, R; Boer, P; Koomans, HA; Joles, JA

    2004-01-01

    Embryo cross-transplantation and cross-fostering between spontaneously hypertensive rats (SHR) and normotensive rats (WKY) suggest that perinatal environment modulates the genetically determined phenotype. In SHR the balance between NO and reactive oxygen species (ROS) is disturbed. We hypothesized

  12. Tubulo-glomerular feedback response: enhancement in adult spontaneously hypertensive rats and effects of anaesthetics

    DEFF Research Database (Denmark)

    Leyssac, P P; Holstein-Rathlou, N H

    1989-01-01

    Open-loop tubulo-glomerular feedback (TGF) responses were measured in halothane anaesthetized spontaneously hypertensive rats (SHR), in normotensive Wistar Kyoto (WKY) and Sprague-Dawley rats (SPRD), and in inactin anaesthetized SPRD. Proximal intratubular free flow pressures (FFP) (13.8-14.7 mm Hg...

  13. A Meta-analysis of angitensin-converting enzyme inhibitors on normotensive early diabetic renal diseases

    Institute of Scientific and Technical Information of China (English)

    GENG Li; GU Ming-jun; LIU Zhi-min; FAN Cheng-hui

    2001-01-01

    To make a systematic assessment on whether the progression of early diabetic renal disease with normotension may be slowed down by angiotensin-converting enzyme (ACE) inhibitors. Methods: Randomized clinical experiments published on MEDLINE from January 1990 to April 1999 and on China Biological Medicine were reviewed for studying the effects of ACE-inhibitors on normotensive patients with early diabetic renal diseases. Based on the inclusion criteria, 10 studies were selected. Their results were combined and analyzed with RevMan3.1 software.Results: The pooled effect of urinary microalbumin excretion rate, systolic blood pressure, diastolic blood pressure and mean arterial blood pressure were -77.502 mg/24 h [-100.748 to-54.256], -5.002 mmHg [-9.630 to 0.685], -2.949mmHg [-4.005 to 1.892], -4.284 mmHg [-5.444 to 3.123] respectively. Using clinical albuminuria as the end-point. The pooled odd ratio was 0.27 [95% CI 0.18 0.40]. The sub-group analysis showed that those results had no difference between type 1 and type 2 diabetes. There was no significant correlation between the pooled effects of urinary micro-albuminuria excretion rate and systolic blood pressure, diastolic blood pressure or mean arterial blood pressure. Conclusion:ACE inhibitors can decline urinary micro-albuminuria excretion rate in normotensive patients with early diabetic renal disease and delay the progression of early diabetic renal disease to clinical albuminuria. These effects may not be dependent on its blood pressure-reduction effect.

  14. Low Plasma Volume in Normotensive Formerly Preeclamptic Women Predisposes to Hypertension.

    Science.gov (United States)

    Scholten, Ralph R; Lotgering, Fred K; Hopman, Maria T; Van Dijk, Arie; Van de Vlugt, Maureen; Janssen, Mirian C H; Spaanderman, Marc E A

    2015-11-01

    Formerly preeclamptic women are at risk for cardiovascular disease. Low plasma volume may reflect latent hypertension and potentially links preeclampsia with chronic cardiovascular disease. We hypothesized that low plasma volume in normotensive formerly preeclamptic women predisposes to hypertension. We longitudinally studied n=104 formerly preeclamptic women in whom plasma volume was measured 3 to 30 months after the preeclamptic pregnancy. Cardiovascular variables were assessed at 2 points in time (3-30 months postpartum and 2-5 years thereafter). Study population was divided into low plasma volume (≤1373 mL/m(2)) and normal plasma volume (>1373 mL/m(2)). Primary end point was hypertension at the second visit: defined as ≥140 mm Hg systolic or ≥90 mm Hg diastolic. Secondary outcome of this study was change in traditional cardiovascular risk profile between visits. Variables correlating univariately with change in blood pressure between visits were introduced in regression analysis. Eighteen of 104 (17%) formerly preeclamptic women who were normotensive at first visit had hypertension at second evaluation 2 to 5 years later. Hypertension developed more often in women with low plasma volume (10/35 [29%]) than in women with normal plasma volume (8/69 [12%]; odds ratio, 3.2; 95% confidence interval, 1.4-8.6). After adjustments, relationship between plasma volume status and subsequent hypertension persisted (adjusted odds ratio, 3.0; 95% confidence interval, 1.1-8.5). Mean arterial pressure at second visit correlated inverse linearly with plasma volume (r=-0.49; Phypertension within 5 years. Women with low plasma volume have higher chance to develop hypertension than women with normal plasma volume. Clinically, follow-up of blood pressure seems warranted in women with history of preeclampsia, even when initially normotensive.

  15. Consciousness from the ground up

    Science.gov (United States)

    Lloyd, Seth

    2013-05-01

    The book Physics in Mind: a Quantum View of the Brain certainly aims high. Written by the eminent biophysicist Werner Loewenstein, its goal is nothing less than a theory that explains our sense of conscious existence, built from the bottom up.

  16. Self-Consciousness, Caring, Relationality

    DEFF Research Database (Denmark)

    Montes Sanchez, Alba

    In the studies of emotion, shame is classified under several labels: a self-conscious emotion, an emotion of self-assessment, a social emotion, and a moral emotion. All of them are supposed to pick out a defining characteristic of shame. Though all of these labels will be under scrutiny at some...

  17. The Awakening of Feminist Consciousness

    Institute of Scientific and Technical Information of China (English)

    熊江

    2013-01-01

    Virginia Woolf in her great novel To the Lighthouse shows her deep concern for women. In this book, she discusses women’s spiritual world and the process of the awakening of feminist consciousness, which is represented by Mrs. Ramsay and Lily Briscoe.

  18. Self-Consciousness, Caring, Relationality

    DEFF Research Database (Denmark)

    Montes Sanchez, Alba

    In the studies of emotion, shame is classified under several labels: a self-conscious emotion, an emotion of self-assessment, a social emotion, and a moral emotion. All of them are supposed to pick out a defining characteristic of shame. Though all of these labels will be under scrutiny at some p...

  19. The Presence of Consciousness in Absence Seizures

    OpenAIRE

    Tim Bayne

    2011-01-01

    This paper examines three respects in which the study of epileptic absence seizures promises to inform our understanding of consciousness. Firstly, it has the potential to bear on debates concerning the behavioural and cognitive functions associated with consciousness. Secondly, it has the potential to illuminate the relationship between background states (or ‘levels’) of consciousness and the contents of consciousness. Thirdly, it has the potential to bear on our understanding of the unity o...

  20. Stable glomerular filtration rate in normotensive IDDM patients with stable microalbuminuria. A 5-year prospective study

    DEFF Research Database (Denmark)

    Mathiesen, E R; Feldt-Rasmussen, B; Hommel, E

    1997-01-01

    OBJECTIVE: To investigate the long-term course of glomerular filtration rate (GFR) in IDDM patients with microalbuminuria in order to identify patients with stable or declining kidney function over a 5-year study. RESEARCH DESIGN AND METHODS: Forty normotensive (129 +/- 11/80 +/- 8 mmHg) IDDM...... min-1.1 x 73 m-2. RESULTS: Using multiple regression analysis, the rate of decline in GFR was independently correlated to onset of diabetic nephropathy (P ... x min-1 x year-1; NS). The difference in the rate of decline of GFR was significant (mean 2.7 ml x min-1 x year-1; P

  1. Urinary protein-to-creatinine ratio indicative of significant proteinuria in normotensive pregnant women.

    Science.gov (United States)

    Baba, Yosuke; Ohkuchi, Akihide; Usui, Rie; Takahashi, Hironori; Matsubara, Shigeki

    2016-07-01

    In hypertensive pregnant women, the protein-to-creatinine (P/C) ratio is well correlated with 24-h proteinuria and a P/C ratio of 0.27 (g/gCr) is used to reflect significant proteinuria (>0.3 g/day). The aim of this study was to obtain data on normotensive pregnant women, which have so far been lacking. The study population consisted of 74 pregnant women who met the following criteria: (i) ≥22 gestational weeks; (ii) a positive result (≥1+) on dipstick test; (iii) a positive result (>0.27) for P/C ratio; and (iv) 24-h urine test performed within 2 days of the P/C ratio. The correlation between the P/C ratio and 24-h proteinuria, the incidence rates of significant proteinuria according to P/C ratios, and appropriate threshold of the P/C ratio to rule in significant proteinuria were determined using the appropriate statistical methods. The P/C ratio was moderately correlated with the 24-h proteinuria, with a correlation coefficient of 0.64 (95% confidence interval, 0.487-0.76). The area under the receiver-operator curve was 0.76 (95% confidence interval, 0.66-0.87); however, no clear shoulder was identifiable. The incidence rates of significant proteinuria according to P/C ratios of 0.27-0.49, 0.50-0.74, 0.75-0.99, and >1 were 41, 66, 100, and 100%, respectively, indicating that all normotensive pregnant women with a P/C ratio > 0.75 had significant proteinuria. Normotensive pregnant women showed a significant correlation between the P/C ratio and 24-h urine protein level. All normotensive pregnant women with a P/C ratio > 0.75 had significant proteinuria, suggesting that a P/C ratio > 0.75 may be the 'rule-in' threshold of significant proteinuria in this population. © 2016 Japan Society of Obstetrics and Gynecology.

  2. Consciousness without a cortex, but what kind of consciousness is this? [editorial

    NARCIS (Netherlands)

    Coenen, A.M.L.

    2007-01-01

    Merker suggests that the thalamocortical system is not an essential system for consciousness, but, instead, that the midbrain reticular system is responsible for consciousness. Indeed, the latter is a crucial system for consciousness, when consciousness is regarded as the waking state. However, when

  3. 8 Questions About the Conscious Mind

    NARCIS (Netherlands)

    Dooremalen, A.J.P.W.

    2014-01-01

    Can the mind function separately from the brain? Can machines have conscious minds? Is Google Maps part of the conscious mind? Hans Dooremalen provides answers to these three and five other questions about the conscious mind in an easy to read introduction to the philosophy of mind.

  4. Self-Consciousness and Aspects of Identity.

    Science.gov (United States)

    Cheek, Jonathan M.; Briggs, Stephen R.

    1982-01-01

    Investigated the relationship between public and private self-consciousness and social and personal aspects of identity. Public self-consciousness correlated more strongly with social than with personal aspects of identity, and private self-consciousness correlated more strongly with personal than with social aspects. Discusses implications for…

  5. Dietary saffron reduced the blood pressure and prevented remodeling of the aorta in L-NAME-induced hypertensive rats

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    Zohreh Nasiri

    2015-11-01

    Full Text Available Objective(s:The aim of this study was to investigate the effects of nutritional saffron (Crocus sativus L. stigma hydroalcoholic extract on blood pressure (BP and histology of the aorta in normotensive and hypertensive rats. Materials and Methods:   Saffron (200 mg/kg/day was given orally for 5 weeks to normotensive and hypertensive rats. Hypertension was induced by NG-nitro-L-arginine methyl ester (L-NAME; 40 mg/kg/day administration in drinking water, and BP was measured weekly. Histological examination of the thoracic aorta included staining with hematoxylin and eosin, orcein, and periodic acid Schiff methods. Results:  Saffron had no effect on normotensive rats, but on hypertensive rats, prevented BP elevation form the third week of treatment (P

  6. Becoming conscious of the American middle class (un)consciousness.

    Science.gov (United States)

    Kroos, Karmo

    2012-09-01

    It is argued in this article that social psychology would make the greatest contribution to research on class identity if it concentrated on the area closest to psychology-analysis of class consciousness. In order to show that the study of the psyche and mentality of the middle class is one of the least researched aspects of the American middle class, a brief overview of the different approaches to the study of the middle class in selected disciplines will be offered. It will be demonstrated that even if the identity of the U.S. middle class cannot be fully understood without its history and the social context in which it operates, it is the study of its (un)consciousness that social psychology should be focusing its research efforts on. The alternative would make social psychology indistinguishable from social history or sociology.

  7. Normotension, prehypertension, and hypertension in urban middle-class subjects in India: prevalence, awareness, treatment, and control.

    Science.gov (United States)

    Gupta, Rajeev; Deedwania, Prakash C; Achari, Vijay; Bhansali, Anil; Gupta, Bal Kishan; Gupta, Arvind; Mahanta, Tulika G; Asirvatham, Arthur J; Gupta, Sunil; Maheshwari, Anuj; Saboo, Banshi; Jali, Mallikarjuna V; Singh, Jitendra; Guptha, Soneil; Sharma, Krishna Kumar

    2013-01-01

    We conducted a multisite study to determine the prevalence and determinants of normotension, prehypertension, and hypertension, and awareness, treatment, and control of hypertension among urban middle-class subjects in India. We evaluated 6,106 middle-class urban subjects (men 3,371; women, 2,735; response rate, 62%) in 11 cities for sociodemographic and biological factors. The subjects were classified as having normotension (BP middle-class urban Asian Indians. Significant associations of hypertension were found with age, dietary fat, consumption of fruits and vegetables, smoking, and obesity. Normotensive individuals had a lower prevalence of cardiometabolic risk factors than did members of the prehypertensive or hypertensive groups. Half of the hypertensive group were aware of having hypertension, a third were receiving treatment for it, and quarter had a controlled BP.

  8. Measuring consciousness in severely damaged brains.

    Science.gov (United States)

    Gosseries, Olivia; Di, Haibo; Laureys, Steven; Boly, Mélanie

    2014-01-01

    Significant advances have been made in the behavioral assessment and clinical management of disorders of consciousness (DOC). In addition, functional neuroimaging paradigms are now available to help assess consciousness levels in this challenging patient population. The success of these neuroimaging approaches as diagnostic markers is, however, intrinsically linked to understanding the relationships between consciousness and the brain. In this context, a combined theoretical approach to neuroimaging studies is needed. The promise of such theoretically based markers is illustrated by recent findings that used a perturbational approach to assess the levels of consciousness. Further research on the contents of consciousness in DOC is also needed.

  9. An information integration theory of consciousness

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    Tononi Giulio

    2004-11-01

    Full Text Available Abstract Background Consciousness poses two main problems. The first is understanding the conditions that determine to what extent a system has conscious experience. For instance, why is our consciousness generated by certain parts of our brain, such as the thalamocortical system, and not by other parts, such as the cerebellum? And why are we conscious during wakefulness and much less so during dreamless sleep? The second problem is understanding the conditions that determine what kind of consciousness a system has. For example, why do specific parts of the brain contribute specific qualities to our conscious experience, such as vision and audition? Presentation of the hypothesis This paper presents a theory about what consciousness is and how it can be measured. According to the theory, consciousness corresponds to the capacity of a system to integrate information. This claim is motivated by two key phenomenological properties of consciousness: differentiation – the availability of a very large number of conscious experiences; and integration – the unity of each such experience. The theory states that the quantity of consciousness available to a system can be measured as the Φ value of a complex of elements. Φ is the amount of causally effective information that can be integrated across the informational weakest link of a subset of elements. A complex is a subset of elements with Φ>0 that is not part of a subset of higher Φ. The theory also claims that the quality of consciousness is determined by the informational relationships among the elements of a complex, which are specified by the values of effective information among them. Finally, each particular conscious experience is specified by the value, at any given time, of the variables mediating informational interactions among the elements of a complex. Testing the hypothesis The information integration theory accounts, in a principled manner, for several neurobiological observations

  10. Variability in blood pressure in normotensive patients undergoing outpatient oral surgery

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    Heriberto Atanacio Núñez Mendieta

    2015-12-01

    Full Text Available Background: A dental appointment can be stressful for patients, especially if this involves a surgical procedure. Factors such as pain and catecholamines present in local anesthesia can cause a change of values of blood pressure (BP. The hypertensive peak is a sudden rise in BP and can occur even in a person usually normotensive by a stressful situation. Objective: To determine the variability of BP in normotensive patients attending the Department of Oral Surgery III Course of the Faculty of Dentistry at the National University of Asuncion. Methods: Descriptive observational study design. The PA was obtained by auscultation method by members of the Department of Physiology of the Faculty of Dentistry at the National University of Asuncion during different stages of the surgical procedure, in 109 patients aged 18 to 67 years who presented indicating teeth extraction. Results: 95.4% (104 of the patients showed variation in the values of BP during the surgical procedure. In 77% of the variation thereof within 5 minutes after local anesthesia, in 18% immediately after tooth extraction and 5% in the immediate postoperative period was observed. Conclusions: In most patients, BP variation was observed during the oral outpatient surgical procedure and surgical stage more often variation was within 5 minutes after administering local anesthesia.

  11. Impact of diabetes and diastolic dysfunction on exercise capacity in normotensive patients without coronary artery disease.

    Science.gov (United States)

    Gürdal, Ahmet; Kasikcioglu, Erdem; Yakal, Sertac; Bugra, Zehra

    2015-05-01

    The aim of this study was to determine the impact of diabetes and diastolic dysfunction on exercise capacity in asymptomatic, normotensive patients with type 2 diabetes without coronary artery disease. A total of 43 type 2 diabetes patients (age: 50 ± 5 years) and 20 healthy controls (age: 48 ± 4 years) were enrolled. Diastolic function was investigated by conventional pulsed-wave (PW) Doppler and tissue Doppler imaging (TDI). Exercise capacity was evaluated with cardiopulmonary exercise testing (CPET). In patients with type 2 diabetes, increase in resting heart rate (HR-rest) (p = 0.013), decrease in maximum heart rate during exercise (HR-max) (p VO2-max) (p VO2-an) (p VO2-max (r = -0.456, p < 0.01) independent of the absence or presence of mild diastolic dysfunction. Exercise capacity was found to be significantly decreased in normotensive patients with type 2 diabetes without coronary artery disease, and this decrease was independent of diastolic dysfunction. © The Author(s) 2015.

  12. 脑室内注射5-羟色胺受体激动剂对正常清醒大鼠排尿反射的影响%Effects of intracerebroventricular administration of 5-hydroxytryptamine receptor agonists on micturition reflex in normal conscious rats

    Institute of Scientific and Technical Information of China (English)

    程曙杰; 吴刚; 曹海兵; 谷宝军

    2011-01-01

    AIM To investigate the effects of intracerebroventricular administration of 5-hydroxytryptamine (5-HT) receptor agonists on micturition reflex in normal conscious rats.METHODS Thirty normal SD rats were randomized into 5 groups.A PE-50 catheter was placed into the dome of the bladder to record intravesical pressure.And a cerebroventricular cannula was inserted into the right ventricle for the injection of 5-HT, 8-hydroxy-N, N-dipropyl-2-aminotetralin (8-OH-DPAT, agonist at 5-HT1A receptor), 1-methyl-5-HT (agonist at 5-HT2 receptor), 2-methyl-5-HT (agonist at 5-HT3 receptor), and 1-( 4-amino-5-chloro2methoxyphenyl)-3-(1-n-butyl-4piperidinyl)-1-propanone hydrochloride (RS67506, agonist at 5-HT4 receptor).The dosage was 6, 18 or 60 nmol ·kg-1, respectively.Micturition pressure, bladder capacity,micturition volume and residual volume etc, before and after the administration were measured.RESULTS In the normal conscious rats, 6 nmol ·kg-1 5HT, 8-OH-DPAT, 1-methyl-5-HT, or RS67506 injected intracerebroventricularly promoted micturition reflex with decreased bladder capacity and residual volume; 18 nmol·kg-1 promoted micturition reflex more significantly.But there was no effect on cystometric parameters in the rats injected with 2-methyl-5-HT.CONCLUSION In normal conscious rats, 5-HT1A, 5-HT2, 5-HT4 receptor agonists can promote the micturition reflex in the level of superspinal central nervous system.%目的 探讨脑室内注射5-羟色胺(5-HT)受体激动剂对正常清醒大鼠排尿反射的影响.方法 SD大鼠30只随机分为5组,将PE-50聚乙烯导管分别插入大鼠膀胱顶部及右侧脑室进行膀胱测压与药物注入.在脑室内分别注入5-HT、5-HTlA受体激动剂8-OH-DPAT、5-HT2受体激动剂1-甲基-5-HT、5-HT3受体激动剂2-甲基-5-HT以及5-HT4受体激动剂RS67506,剂量分别为6、18或60 nmol·kg-1.记录给药前后的排尿压力、膀胱容量、排尿量以及残尿量等指数的变化.结果 6 nmol·kg-1剂量的5-HT、8

  13. The Moral Insignificance of Self-consciousness.

    Science.gov (United States)

    Shepherd, Joshua

    2017-06-01

    In this paper, I examine the claim that self-consciousness is highly morally significant, such that the fact that an entity is self-conscious generates strong moral reasons against harming or killing that entity. This claim is apparently very intuitive, but I argue it is false. I consider two ways to defend this claim: one indirect, the other direct. The best-known arguments relevant to self-consciousness's significance take the indirect route. I examine them and argue that (a) in various ways they depend on unwarranted assumptions about self-consciousness's functional significance, and (b) once these assumptions are undermined, motivation for these arguments dissipates. I then consider the direct route to self-consciousness's significance, which depends on claims that self-consciousness has intrinsic value or final value. I argue what intrinsic or final value self-consciousness possesses is not enough to generate strong moral reasons against harming or killing.

  14. Consistency between recognition and behavior creates consciousness

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    Keita Inaba

    2004-08-01

    Full Text Available What is consciousness? Is it possible to create consciousness mechanically? Various studies have been performed in the fields of psychology and cerebral science to answer these questions. As of yet, however, no researchers have proposed a model capable of explaining the mind-body problem described by Descartes or replicating a consciousness as advanced as that of human beings. Ancient people believed that the consciousness resided in a Homunculus, a human in miniature who lived in the brain. It is no mystery that the ancients came up with such an idea; for consciousness has always been veiled in mystery, beyond the reach of our explorative powers. We can assert, however, that consciousness does not "live" in us, but "exists" in us. Insofar as the processes occurring inside the human brain are a product of the physical activity of the neurons that reside there, we believe that it should be possible to define consciousness systematically.

  15. Effects of curative treatment emphasizing endurance training on the performance and blood pressure of hypertensive and normotensives

    Science.gov (United States)

    Worms, F.

    1981-01-01

    The problem of normal values of blood pressure after exercise taking into account the blood pressure at the end of the exercise test is discussed. Hypertensives showed a lower working capacity than normotensives. In normotensives, however, systolic blood pressure at the end of an exercise correlated well with the working capacity. After the endurance cure submaximal blood pressure was markedly lower in hypertensives with a striking dependence on the level of initial values. Systolic blood pressure at the end of an exercise test was not changed significantly. Most probably it is not possible to overcome this malregulation in hypertensives by endurance training alone.

  16. Chronic resistance training does not affect post-exercise blood pressure in normotensive older women: a randomized controlled trial

    OpenAIRE

    Gerage,Aline Mendes; Ritti-Dias, Raphael Mendes; do Nascimento, Matheus Amarante; Pina,Fábio Luiz Cheche; Gonçalves,Cássio Gustavo Santana; Sardinha, Luís B; Edilson Serpeloni CYRINO

    2015-01-01

    Resistance training has been recommended for maintenance or improvement of the functional health of older adults, but its effect on acute cardiovascular responses remains unclear. Thus, the purpose of this study was to analyze the effect of 12 weeks of resistance training on post-exercise blood pressure (BP) in normotensive older women. Twenty-eight normotensive and physically inactive women (≥60 years) were randomly assigned to a training group (TG) or a control group (CG). The TG underwent ...

  17. Integrated approach to cost consciousness

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, R.E.

    1988-01-01

    Cost consciousness was given a very necessary boost by the collapse of oil prices in 1986 and downward movements in prices have served to re-inforce the need for vigilance: oil companies were becoming complacent. The climate necessary for cost consciousness to flourish as part of the oil company culture is established by higher management attitude and can be reinforced by organizational structure. British Petroleum's current production/exploration organisational structure is reported on in the first section of this paper and this is followed by a discussion of pertinent cost-oriented observations to emerge from this grouping related both to the component phases of the exploitation of a field, and to the cost of engineering/managing same.

  18. Evidence for a communal consciousness.

    Science.gov (United States)

    Bobrow, Robert S

    2011-01-01

    Recently described social network phenomena show that emotionally connected people come to share certain traits, including obesity, happiness, and loneliness. These do not appear to be mediated by face-to-face contact. Other examples of groups with a common connection that act in unison are mass hysteria, menstrual synchrony, and the ability of a group to guess the number of jelly beans in a jar. The animal kingdom abounds with examples of groups functioning as a single whole: fish school, birds flock, hoofed animals herd, ant and bee colonies work as a single organism. Try as they might, neuroscientists have been unable to find an anatomical seat of consciousness within the brain. C.G. Jung's realization of a collective unconscious began with an observation of a patient whose thoughts matched previous writings that the patient had never seen. The "emotional telepathy" of social network phenomena suggests a collective/communal consciousness as well.

  19. Classical Coherence, Life and Consciousness

    Science.gov (United States)

    Ghose, Partha

    2014-07-01

    There have been many claims that quantum mechanics plays a key role in the origin and/or operation of biological organisms, beyond merely providing the basis for the shapes and sizes of biological molecules and their chemical affinities. These range from Schrödinger's suggestion that quantum fluctuations produce mutations, to Hameroff and Penrose's conjecture that quantum coherence in microtubules is linked to consciousness. I review some of these claims in this paper, and discuss the serious problem of decoherence.

  20. Conscious sedation: A dying practice?

    OpenAIRE

    Manickam, Palaniappan; Kanaan, Ziad; Zakaria, Khalid

    2013-01-01

    Sedation practices vary according to countries with different health system regulations, the procedures done, and local circumstances. Interestingly, differences in the setting in which the practice of gastroenterology and endoscopy takes place (university-based vs academic practice) as well as other systematic practice differences influence the attitude of endoscopists concerning sedation practices. Conscious sedation using midazolam and opioids is the current standard method of sedation in ...

  1. Peripheral Vascular Resistance Impairment during Isometric Physical Exercise in Normotensive Offspring of Hypertensive Parents

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    Natália Portela

    Full Text Available Abstract Background: A family history of hypertension is associated with vascular and autonomic abnormalities, as well as an impaired neurohemodynamic response to exercise. Objective: To test the hypothesis that normotensive individuals with a family history of hypertension present an impaired peripheral vascular resistance response to exercise. Methods: The study included 37 normotensive volunteers of both sexes who were sedentary, eutrophic, and nonsmokers, comprising 23 with (FH+; 24 ± 3 years and 14 without (FH-; 27 ± 5 years a family history of hypertension. Blood pressure, heart rate (DIXTAL®, forearm blood flow (Hokanson®, and peripheral vascular resistance were simultaneously measured for 3 minutes during rest and, subsequently, for 3 minutes during an isometric exercise at 30% of maximal voluntary contraction (Jamar®. Results: At rest, the FH+ and FH- groups present similar mean blood pressure (83 ± 7 versus 83 ± 5 mmHg, p = 0.96, heart rate (69 ± 8 bpm versus 66 ± 7 bpm, p = 0.18, forearm blood flow (3 ± 1 mL/min/100 mL versus 2.7 ± 1 mL/min/100 mL, p = 0.16, and peripheral vascular resistance (30 ± 9 units versus 34±9 units, p = 0.21, respectively. Both groups showed a significant and similar increase in mean blood pressure (∆ = 15 ± 7 mmHg versus 14 ± 7 mmHg, p = 0.86, heart rate (∆ = 12 ± 8 bpm versus 13 ± 7 bpm, p = 0.86, and forearm blood flow (∆ = 0.8 ± 1.2 mL/min/100 mL versus 1.4 ± 1.1 mL/min/100 mL, p = 0.25, respectively, during exercise. However, individuals in the FH+ group showed no reduction in peripheral vascular resistance during exercise, which was observed in the FH- group (∆ = -0.4 ± 8.6 units versus -7.2 ± 6.3 units, p = 0.03. Conclusion: Normotensive individuals with a family history of hypertension present an impaired peripheral vascular resistance response to exercise.

  2. Left ventricular dysfunction in normotensive type II diabetic patients in Port Harcourt, Nigeria

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    Dodiyi-Manuel ST

    2013-09-01

    Full Text Available Sotonye T Dodiyi-Manuel,1 Maclean R Akpa,2 Osaretin J Odia2 1Department of Medicine, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria; 2Department of Medicine, Faculty of Clinical Sciences, University of Port Harcourt, Port Harcourt, Nigeria Background: Diabetes mellitus (DM is on the increase globally. Cardiovascular complications, such as left ventricular dysfunction is a major cause of death in patients with type II DM. Prior to the development of symptomatic heart failure, subclinical left ventricular dysfunction (systolic and diastolic may exist for some time. Aim: The aim of the study was to determine the prevalence of left ventricular dysfunction in non-hypertensive type II DM patients. Methods: A cross sectional study of left ventricular function in 90 normotensive type II diabetes mellitus patients using echocardiography was carried out. Healthy normotensive controls matched for age, sex, and body mass index were selected for comparison. Patients and controls who had hypertension (blood pressure of >140/90 mmHg, history of smoking, significant alcohol history, pregnancy, features of thyroid disease, or valvular heart disease were excluded. Left ventricular diastolic and systolic functions were assessed. Results: Ninety patients, (39 males and 51 females and 90 healthy controls (39 males and 51 females were enrolled. Mean age of patients was 50.76 ± 9.13 years and 51.33 ± 7.84 years for controls. Mean body mass index was 26.88 ± 4.73 kg/m2 in patients and 27.09 ± 4.04 kg/m2 in controls. Mean ejection fraction was 62.4% ± 8.47% and 68.52% ± 7.94% in patients and controls, respectively (P 99 kg/m2 in females and >115 kg/m2 in males was considered abnormal. The left ventricular mass index was also higher in patients than in controls (95.17 ± 25.67 g/m2 versus 85.40 ± 18.0 g/m2; P = 0.004. Conclusion: Normotensive diabetic patients have a high prevalence of left ventricular dysfunction even in the absence of

  3. Repeated measures of inflammation and oxidative stress biomarkers in preeclamptic and normotensive pregnancies.

    Science.gov (United States)

    Ferguson, Kelly K; Meeker, John D; McElrath, Thomas F; Mukherjee, Bhramar; Cantonwine, David E

    2017-05-01

    Preeclampsia is a prevalent and enigmatic disease, in part characterized by poor remodeling of the spiral arteries. However, preeclampsia does not always clinically present when remodeling has failed to occur. Hypotheses surrounding the "second hit" that is necessary for the clinical presentation of the disease focus on maternal inflammation and oxidative stress. Yet, the studies to date that have investigated these factors have used cross-sectional study designs or small study populations. In the present study, we sought to explore longitudinal trajectories, beginning early in gestation, of a panel of inflammation and oxidative stress markers in women who went on to have preeclamptic or normotensive pregnancies. We examined 441 subjects from the ongoing LIFECODES prospective birth cohort, which included 50 mothers who experienced preeclampsia and 391 mothers with normotensive pregnancies. Participants provided urine and plasma samples at 4 time points during gestation (median, 10, 18, 26, and 35 weeks) that were analyzed for a panel of oxidative stress and inflammation markers. Oxidative stress biomarkers included 8-isoprostane and 8-hydroxydeoxyguanosine. Inflammation biomarkers included C-reactive protein, the cytokines interleukin-1β, -6, and -10, and tumor necrosis factor-α. We created Cox proportional hazard models to calculate hazard ratios based on time of preeclampsia diagnosis in association with biomarker concentrations at each of the 4 study visits. In adjusted models, hazard ratios of preeclampsia were significantly (Pinflammation biomarkers that were measured at visit 2 (median, 18 weeks; hazard ratios, 1.31-1.83, in association with an interquartile range increase in biomarker). Hazard ratios at this time point were the most elevated for C-reactive protein, for interleukin-1β, -6, and -10, and for the oxidative stress biomarker 8-isoprostane (hazard ratio, 1.68; 95% confidence interval, 1.14-2.48) compared to other time points. Hazard ratios for

  4. Cerebral small-resistance artery structure and cerebral blood flow in normotensive subjects and hypertensive patients

    Energy Technology Data Exchange (ETDEWEB)

    De Ciuceis, Carolina; Porteri, Enzo; Rizzoni, Damiano; Boari, Gianluca E.M.; Rosei, Enrico Agabiti [University of Brescia, Clinica Medica, Department of Clinical and Experimental Sciences, Brescia (Italy); Cornali, Claudio; Mardighian, Dikran; Fontanella, Marco M. [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Pinardi, Chiara [Spedali Civili, Medical Physics Unit, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Rodella, Luigi F.; Rezzani, Rita [University of Brescia, Section of Anatomy, Department of Clinical and Experimental Sciences, Brescia (Italy); Gasparotti, Roberto [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy)

    2014-12-15

    The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients. Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients. Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19, p < 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33, p < 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45, p < 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9, p < 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012, p < 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28, p < 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (r = -0.516, p < 0.05), basal ganglia (r = -0.521, p < 0.05), thalami (r = -0.527 p < 0.05), and subcortical white matter (r = -0.612, p < 0.01). Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences. (orig.)

  5. Cerebral small-resistance artery structure and cerebral blood flow in normotensive subjects and hypertensive patients.

    Science.gov (United States)

    De Ciuceis, Carolina; Cornali, Claudio; Porteri, Enzo; Mardighian, Dikran; Pinardi, Chiara; Fontanella, Marco M; Rodella, Luigi F; Rezzani, Rita; Rizzoni, Damiano; Boari, Gianluca E M; Rosei, Enrico Agabiti; Gasparotti, Roberto

    2014-12-01

    The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients. Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients. Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19, p < 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33, p < 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45, p < 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9, p < 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012, p < 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28, p < 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (r = -0.516, p < 0.05), basal ganglia (r = -0.521, p < 0.05), thalami (r = -0.527 p < 0.05), and subcortical white matter (r = -0.612, p < 0.01). Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences.

  6. The influence of different sodium loads on renin release in hypertensive and normotensive states of chronic renal failure.

    Science.gov (United States)

    Kornerup, H J

    1978-04-01

    The purpose of the present study was to examine the influence of different sodium loads on renin release in the hypertensive and normotensive state of chronic renal failure. Blood pressure (BP), plasma renin concentration (PRC) and exchangeable sodium (NaE) were measured in eighteen patients with advanced chronic renal failure, nine hypertensives and nine normotensives, and in seven normal subjects (a) 6 days after a fixed sodium intake of 10 mmol/day, and (b) 6 days after a fixed sodium intake of 150 mmol/day. Mean NaE was 14-19% higher in the hypertensives compared with the normotensives and values of NaE correlated significantly to values of mean BP. No significant differences were present in PRC between the groups of patients and controls on either of the sodium regimens and no correlation was found between BP and PRC. However, average decreases of PRC in the hypertensives on high sodium intake, 33-34%, were significantly lower than the corresponding values of 69-71% in the normotensive patients and controls, respectively. Furthermore, the percentage changes of PRC on high sodium intake correlated significantly to mean BP as well as to NaE. These results suggest that renin release is relatively unresponsive to different sodium intakes in hypertension following chronic renal failure. This alteration in renin release may contribute to the maintenance of hypertension in chronic renal failure, PRC being "inappropriately' increased in relationship to the sodium excess.

  7. A comparison of the haemodynamic and behavioural effects of moxonidine and clonidine in normotensive subjects.

    Science.gov (United States)

    Macphee, G J; Howie, C A; Elliott, H L; Reid, J L

    1992-01-01

    1. This randomised double-blind placebo controlled crossover study in healthy normotensive males compared the haemodynamic and behavioural responses following single oral doses of moxonidine (200 micrograms), clonidine (200 micrograms) and placebo. 2. Both active drugs significantly reduced blood pressure as compared with placebo: on average (over the study day) by -5.6/-0.8 with moxonidine and by -13.3/-5.3 mm Hg with clonidine. The hypotensive effect of clonidine was significantly greater (95% CI 3.2-12.2). Heart rate was unchanged by either drug. 3. Psychomotor testing, salivary flow and side effect reporting showed a consistent treatment rank order similar to that of the hypotensive response: clonidine greater than moxonidine greater than placebo. 4. Although moxonidine produced less adverse effects than clonidine, an equivalent hypotensive response was not demonstrated in normal subjects. Further study at comparable antihypertensive doses is required to clarify the relative side effect profile of these agents. PMID:1576046

  8. Fibromuscular Dysplasia in a Normotensive Patient Presented With Renal Infarct: Case Report and Endovascular Technique.

    Science.gov (United States)

    Rostambeigi, Nassir; Goldfarb, Robert; Hunter, David W; Anderson, James Kyle

    2015-10-01

    Fibromuscular dysplasia (FMD) is a well-known disease, but its diagnosis can be challenging. Typically, the symptomatic FMD are reported by young and middle aged people with high blood pressure refractory to medical treatment. We present a rare case of a young, healthy, and normotensive patient who presented with pain secondary to renal infarction, without any prior signs or symptoms or history of hypertension. This presentation of FMD has not been previously described. The typical but subtle angiographic findings of the macro-aneurysmal FMD as well as the successful endovascular treatment are discussed herein. The macro-aneurysmal form of FMD should be considered in the differential diagnosis of acute renal infarction in young and middle aged patients even if they do not have a history of hypertension.

  9. The cerebral hemodynamics of normotensive hypovolemia during lower-body negative pressure

    Science.gov (United States)

    Giller, C. A.; Levine, B. D.; Meyer, Y.; Buckey, J. C.; Lane, L. D.; Borchers, D. J.

    1992-01-01

    Although severe hypovolemia can lead to hypotension and neurological decline, many patients with neurosurgical disorders experience a significant hypovolemia while autonomic compensatory mechanisms maintain a normal blood pressure. To assess the effects of normotensive hypovolemia upon cerebral hemodynamics, transcranial Doppler ultrasound monitoring of 13 healthy volunteers was performed during graded lower-body negative pressure of up to -50 mm Hg, an accepted laboratory model for reproducing the physiological effects of hypovolemia. Middle cerebral artery flow velocity declined by 16% +/- 4% (mean +/- standard error of the mean) and the ratio between transcranial Doppler ultrasound pulsatility and systemic pulsatility rose 22% +/- 8%, suggesting cerebral small-vessel vasoconstriction in response to the sympathetic activation unmasked by lower-body negative pressure. This vasoconstriction may interfere with the autoregulatory response to a sudden fall in blood pressure, and may explain the common observation of neurological deficit during hypovolemia even with a normal blood pressure.

  10. Markers of obesity and growth in preeclamptic and normotensive pregnant women.

    Science.gov (United States)

    Kharb, S; Bala, J; Nanda, S

    2017-07-01

    The objective of the study was to analyse leptin, IGF-1, Apo A, lipoproteins, haem oxygenase-1 (HO-1) in maternal sera and venous umbilical cord sera of newborn babies of 25 preeclamptics (group II), and 25 normotensive pregnant women (group I) as markers of obesity and growth in preeclamptic and normotensive pregnant women. Apo A I and II levels were estimated by competitive immunoassay using direct chemiluminiscence technology. Haem oxygenase-1 (HO-1), leptin and IGF-1 were analysed by ELISA. Maternal and cord blood levels of homocysteine, folic acid, lipid profile (namely, total cholesterol, triglycerides, LDL-C, VLDL-C and HDL-C), Haem oxygenase 1 were higher in preeclamptic women as compared to normotensive pregnant women. Serum and cord blood Apo A-I and Apo B, leptin levels, IGF-I were lower in preeclamptic women as compared to normotensive pregnant. The findings of high serum HO-1 levels in maternal and cord blood in preeclampsia supports the role of oxidative stress and excessive inflammatory response in the pathogenesis of preeclampsia. It seems likely that IGF-1 and leptin play a central role in controlling foetal growth. There is increasing evidence that the foundations of life-long health are, in part, laid in the uterus. Findings of present study suggest that alterations in biochemical markers of growth and obesity occur in mothers and foetuses and modifications of uterine environment can be of help to prevent future cardiovascular risk. Impact statement Preeclampsia has been reported to be associated with an increased risk of later life cardiovascular disease. However, information regarding how obesity increases the risk of preeclampsia is limited. Atherogenic milieu occurring during pregnancy persists into adulthood and foetal growth retardation is strongly associated with adult atherosclerosis. There is conflicting evidence regarding alterations of IGFs in preeclamptic pregnancies and deficit in circulating and cord blood IGF-1 levels in

  11. Consciousness and the Invention of Morel

    Science.gov (United States)

    Perogamvros, Lampros

    2013-01-01

    A scientific study of consciousness should take into consideration both objective and subjective measures of conscious experiences. To this date, very few studies have tried to integrate third-person data, or data about the neurophysiological correlates of conscious states, with first-person data, or data about subjective experience. Inspired by Morel's invention (Casares, 1940), a literary machine capable of reproducing sensory-dependent external reality, this article suggests that combination of virtual reality techniques and brain reading technologies, that is, decoding of conscious states by brain activity alone, can offer this integration. It is also proposed that the multimodal, simulating, and integrative capacities of the dreaming brain render it an “endogenous” Morel's machine, which can potentially be used in studying consciousness, but not always in a reliable way. Both the literary machine and dreaming could contribute to a better understanding of conscious states. PMID:23467765

  12. Freudian theory and consciousness: A conceptual analysis

    Directory of Open Access Journals (Sweden)

    De Sousa Avinash

    2011-01-01

    Full Text Available This paper aims at taking a fresh look at Freudian psychoanalytical theory from a modern perspective. Freudian psychology is a science based on the unconscious (id and the conscious (ego. Various aspects of Freudian thinking are examined from a modern perspective and the relevance of the psychoanalytical theory of consciousness is projected. Do psychoanalysis and the unconsciousness have something to teach us about consciousness? Approaching Freud from a historical, psychoanalytical, anthropological and sociological perspective, we need to look at how Freudian theory may contribute to a better understanding of consciousness. We also need to look at psychoanalytical psychotherapy and its contribution to a better understanding of body-mind dualism and consciousness as a whole. Ego psychology is considered in the present day context and it is synthesized with various psychological studies to give us a better understanding of consciousness.

  13. Freudian theory and consciousness: A conceptual analysis

    Directory of Open Access Journals (Sweden)

    Avinash De Sousa

    2011-03-01

    Full Text Available This paper aims at taking a fresh look at Freudian psychoanalytical theory from a modern perspective. Freudian psychology is a science based on the unconscious (id and the conscious (ego. Various aspects of Freudian thinking are examined from a modern perspective and the relevance of the psychoanalytical theory of consciousness is projected. Do psychoanalysis and the unconsciousness have something to teach us about consciousness? Approaching Freud from a historical, psychoanalytical, anthropological and sociological perspective, we need to look at how Freudian theory may contribute to a better understanding of consciousness. We also need to look at psychoanalytical psychotherapy and its contribution to a better understanding of body-mind dualism and consciousness as a whole. Ego psychology is considered in the present day context and it is synthesized with various psychological studies to give us a better understanding of consciousness.

  14. Freudian theory and consciousness: a conceptual analysis**.

    Science.gov (United States)

    De Sousa, Avinash

    2011-01-01

    This paper aims at taking a fresh look at Freudian psychoanalytical theory from a modern perspective. Freudian psychology is a science based on the unconscious (id) and the conscious (ego). Various aspects of Freudian thinking are examined from a modern perspective and the relevance of the psychoanalytical theory of consciousness is projected. Do psychoanalysis and the unconsciousness have something to teach us about consciousness? Approaching Freud from a historical, psychoanalytical, anthropological and sociological perspective, we need to look at how Freudian theory may contribute to a better understanding of consciousness. We also need to look at psychoanalytical psychotherapy and its contribution to a better understanding of body-mind dualism and consciousness as a whole. Ego psychology is considered in the present day context and it is synthesized with various psychological studies to give us a better understanding of consciousness.

  15. Conscious Pulse II The rules of engagement

    CERN Document Server

    Mould, R A

    2002-01-01

    This is the final paper in a series that considers the rules of engagement between conscious states and physiological states. In this paper, we imagine that an endogenous quantum mechanical superposition is created by a classical stimulus, and that this leads to a `physiological pulse' of states that are in superposition with one another. This pulse is correlated with a `conscious pulse' of the kind discussed in a previous paper (Conscious Pulse I). We then add a rule (5) to the four rules previously given. This rule addresses the effect of `pain' consciousness on both of these pulses, and in doing so, it validates the "Parallel Principle" applied to pain. Key words: Brain states, cat paradox, consciousness, conscious observer, macroscopic superposition, measurement, state reduction, state collapse, von Neumann.

  16. Consciousness and the Invention of Morel

    Directory of Open Access Journals (Sweden)

    Lampros ePerogamvros

    2013-03-01

    Full Text Available A scientific study of consciousness should take into consideration both objective and subjective measures of conscious experiences. To this date, very few studies have tried to integrate third-person data, or data about the neurophysiological correlates of conscious states, with first-person data, or data about subjective experience. Inspired by Morel’s invention (Casares, 1940, a literary machine capable of reproducing sensory-dependent external reality, this article suggests that combination of virtual reality techniques and brain reading technologies, that is, decoding of conscious states by brain activity alone, can offer this integration. It is also proposed that the multimodal, simulating and integrative capacities of the dreaming brain render it an 'endogenous' Morel's machine, which can potentially be used in studying consciousness, but not always in a reliable way. Both the literary machine and dreaming could contribute to a better understanding of conscious states.

  17. Low-dose esmolol: hemodynamic response to endotracheal intubation in normotensive patients

    Directory of Open Access Journals (Sweden)

    Suresh Lakshmanappa

    2012-06-01

    Full Text Available Abstract Purpose: Endotracheal intubation is a frequently utilized and highly invasive component of anesthesia that is often accompanied by potentially harmful hemodynamic pressor responses. The purpose of this study was to investigate the efficiency of a single pre-induction 1 mg/kg bolus injection of esmolol for attenuating these hemodynamic responses to endotracheal intubation in normotensive patients. Material and methods: The study was composed of 100 randomly selected male and female patients between the ages of 18 and 60 that were scheduled for elective surgery and belonged to ASA grade I or II. Two minutes prior to intubation the control group received 10 mL of saline (n=50 and the experimental group received an injection of esmolol 1 mg/kg diluted to 10 mL (n=50. Heart rate (HR, systolic blood pressure (SBP, diastolic blood pressure (DBP, mean arterial pressure (MAP, and rate pressure product (RPP were compared to basal values before receiving medication (T-0, during pre-induction (T-1, induction (T-2, intubation (T-3, and post-intubation at 1 (T-4, 3 (T-6, 5 (T-8, and 10 (T-13 minutes. Results: Esmolol significantly attenuated the hemodynamic responses to endotracheal intubation at the majority of measured points. Attenuation of HR (10.8%, SBP (7.04%, DBP (3.99%, MAP (5%, and RPP (16.9% was observed in the esmolol group when compared to the control group values. Conclusions: A single pre-induction 1 mg/kg bolus injection of esmolol successfully attenuated the hemodynamic pressor response in normotensive patients. A significant attenuation of heart rate, systolic blood pressure, diastolic blood pressure and mean arterial pressure was observed at the majority of measured time points in the esmolol administered group compared to the control group. [J Contemp Med 2012; 2(2.000: 69-76

  18. Carotid intima-media thickness and elastic properties of aortas in normotensive children of hypertensive parents.

    Science.gov (United States)

    Yildirim, Ali; Kosger, Pelin; Ozdemir, Gokmen; Sahin, Fezan Mutlu; Ucar, Birsen; Kilic, Zubeyir

    2015-09-01

    A significant correlation between hypertension history and high blood pressure has been observed with regard to age, race and gender. Investigating carotid intima-media thickness and aortic stiffness prior to the development of hypertension in children of hypertensive parents enabled us to evaluate these patients for subclinical atherosclerosis. We compared carotid intima-media thickness, aortic strain, distensibility, stiffness indices and elastic modulus in 67 normotensive children whose parents had a diagnosis of essential hypertension and 39 normotensive children with no parental history of hypertension. Although there were no significant differences between the two groups in terms of systolic blood pressure, diastolic blood pressure, average blood pressure and pulse pressure (P>0.05), systolic blood pressures were higher among patients 15 years and older in the study group. No significant differences were noted between the control and study groups regarding interventricular septal thickness, left-ventricular posterior wall thickness, left-ventricular systolic and diastolic diameter and aortic annulus diameter (P>0.05). The left atrium diameter was larger in the study group compared with that in the control group, mainly because of the values of the 15-year-old and older children (P=0.01). The mean, maximum and minimum values of carotid intima-media thickness were significantly different in the study group compared with the control group among all age groups (Pchildren of hypertensive parents compared with the control group (P=0.014, P=0.001, respectively). Although there were no differences between the study and control groups regarding aortic strain, aortic distensibility, elastic modulus and stiffness indices (P>0.05), aortic distensibility was lower, and aortic stiffness indices were higher among children 15 years and older in the study group. An increase in the carotid intima-media thickness in all age groups and a decrease in aortic elastic properties in

  19. Awaking Blood Pressure Surge and Progression to Microalbuminuria in Type 2 Normotensive Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Michelangela Barbieri

    2016-01-01

    Full Text Available Background. We investigated the predictive value of morning blood pressure surge (MBPS on the development of microalbuminuria in normotensive adults with a recent diagnosis of type 2 diabetes. Methods. Prospective assessments of 24-hour ambulatory blood pressure monitoring and urinary albumin excretion were performed in 377 adult patients. Multivariate-adjusted Cox regression models were used to assess hazard ratios (HRs between baseline and changes over follow-up in MBPS and the risk of microalbuminuria. The MBPS was calculated as follows: mean systolic BP during the 2 hours after awakening minus mean systolic BP during the 1 hour that included the lowest sleep BP. Results. After a mean follow-up of 6.5 years, microalbuminuria developed in 102 patients. An increase in MBPB during follow-up was associated with an increased risk of microalbuminuria. Compared to individuals in the lowest tertile (−0.67±1.10 mmHg, the HR and 95% CI for microalbuminuria in those in the highest tertile of change (24.86±6.92 mmHg during follow-up were 17.41 (95% CI 6.26–48.42; p for trend <0.001. Mean SD MBPS significantly increased in those who developed microalbuminuria from a mean [SD] of 10.6 [1.4] to 36.8 [7.1], p<0.001. Conclusion. An increase in MBPS is associated with the risk of microalbuminuria in normotensive adult patients with type 2 diabetes.

  20. Fibroblast Growth Factor-23 in Obese, Normotensive Adolescents is Associated with Adverse Cardiac Structure

    Science.gov (United States)

    Ali, Farah N.; Falkner, Bonita; Gidding, Samuel S.; Price, Heather E.; Keith, Scott W.; Langman, Craig B.

    2014-01-01

    Objectives Fibroblast growth factor-23 (FGF23) is a biomarker for cardiovascular (CV) disease. Obesity may promote FGF23 production in the absence of chronic kidney disease (CKD). We sought to determine among normotensive African American adolescents, whether FGF23 levels are higher in obese compared with normal weight African American adolescents; and to determine the relationship of FGF23 with markers of cardiac structure and insulin resistance. Study design Cross-sectional data were obtained from a cohort of 130 normotensive, African American adolescents aged 13-18 years old without CKD; 74 were obese; 56 were normal weight. Plasma C-terminal FGF23, fasting glucose and insulin, and hsCRP were measured; participants underwent M-mode echocardiography. Results FGF23 was skewed and approximately normally distributed after natural log transformation (logFGF23). FGF23 levels were higher in obese versus normal weight participants (geometric mean 43 vs. 23 RU/mL, p<0.01). FGF23 values were significantly higher in participants with eccentric or concentric cardiac hypertrophy compared with those without hypertrophy (p<0.01). LogFGF23 directly correlated with BMI, BMI z-score, waist circumference, fasting insulin levels, and HOMA scores. Regression models adjusted for age, sex, and hsCRP suggest that each 10% increase in FGF23 is associated with 1.31 unit increase in LVM (p<0.01), 0.29 unit increase in LVMI (p<0.01), and 0.01 unit increase in left atrial dimension indexed to height (p=0.02). Conclusions In this sample of obese African American adolescents, FGF23 blood levels were associated with abnormal cardiac structure. We postulate that FGF23 may be an early marker of cardiac injury in obese but otherwise healthy African American adolescents. PMID:25063724

  1. Chronic kidney disease predicts impaired membrane microviscosity of red blood cells in hypertensive and normotensive subjects.

    Science.gov (United States)

    Tsuda, Kazushi

    2013-01-01

    Current evidence indicates that abnormalities in physical properties of the cell membranes may be strongly linked to hypertension and other circulatory disorders. Recent studies have shown that chronic kidney disease (CKD) might be a risk factor for cardiovascular and cerebrovascular outcomes. The purpose of the present study was to examine the possible relationship between kidney function and membrane fluidity (a reciprocal value of membrane microviscosity) of red blood cells (RBCs) in hypertensive and normotensive subjects using an electron spin resonance (ESR) and spin-labeling method. The order parameter (S) for the ESR spin-label agent (5-nitroxide stearate) in RBC membranes was significantly higher in hypertensive subjects than in normotensive subjects, indicating that membrane fluidity was decreased in hypertension. The order parameter (S) of RBCs was inversely correlated with estimated glomerular filtration rate (eGFR), suggesting that a decreased eGFR value might be associated with reduced membrane fluidity of RBCs. Multivariate regression analysis also demonstrated that, after adjustment for general risk factors, eGFR might be a significant predictor of membrane fluidity of RBCs. The reduced levels of both membrane fluidity of RBCs and eGFR were associated with increased plasma 8-iso-prostaglandin F2α (an index of oxidative stress) and decreased plasma nitric oxide (NO)-metabolites, suggesting that kidney function could be a determinant of membrane microviscosity of RBCs, at least in part, via oxidative stress- and NO-dependent mechanisms. The ESR study suggests that CKD might have a close correlation with impaired rheologic behavior of RBCs and microcirculatory disorders in hypertensive subjects.

  2. Freudian theory and consciousness: A conceptual analysis

    OpenAIRE

    Avinash De Sousa

    2011-01-01

    This paper aims at taking a fresh look at Freudian psychoanalytical theory from a modern perspective. Freudian psychology is a science based on the unconscious (id) and the conscious (ego). Various aspects of Freudian thinking are examined from a modern perspective and the relevance of the psychoanalytical theory of consciousness is projected. Do psychoanalysis and the unconsciousness have something to teach us about consciousness? Approaching Freud from a historical, psychoanalytical, anthro...

  3. Evolving Complexity, Cognition, and Consciousness

    Science.gov (United States)

    Liljenström, H.

    2012-12-01

    All through the history of the universe there is an apparent tendency for increasing complexity, with the organization of matter in evermore elaborate and interactive systems. The living world in general, and the human brain in particular, provides the highest complexity known. It seems obvious that all of this complexity must be the result of physical, chemical and biological evolution, but it was only with Darwin that we began to get a scientific understanding of biological evolution. Darwinian principles are guiding in our understanding of such complex systems as the nervous system, but also for the evolution of human society and technology. Living organisms have to survive in a complex and changing environment. This implies response and adaption to environmental events and changes at several time scales. The interaction with the environment depends on the present state of the organism, as well as on previous experiences stored in its molecular and cellular structures. At a longer time scale, organisms can adapt to slow environmental changes, by storing information in the genetic material carried over from generation to generation. This phylogenetic learning is complemented by ontogenetic learning, which is adaptation at a shorter time scale, occuring in non-genetic structures. The evolution of a nervous system is a major transition in biological evolution and allows for an increasing capacity for information storage and processing, increasing chances of survival. Such neural knowledge processing, cognition, shows the same principal features as nonneural adaptive processes. Similarly, consciousness might appear, to different degrees, at different stages in evolution. Both cognition and consciousness depends critically on the organization and complexity of the organism. In this presentation, I will briefly discuss general principles for evolution of complexity, focussing on the evolution of the nervous system, which provides organisms with ever increasing

  4. Vladimir Nabokov’ s Political Consciousness

    Institute of Scientific and Technical Information of China (English)

    马红旗

    2006-01-01

    This study consists of three parts. PartⅠ, entitled " Nabokov’ s Women," concentrates on the analysis of Nabokov’ s major women identities of different types. My purpose is to demonstrate that in his creation of the women characters, Nabokov’ s political consciousness—mainly his vindication of individual freedom—is unmistakably, although indirectly, exemplified. Due to the different types of women discussed in this study, and also due to the different aspect of his political consciousness that is emphasized in different women identities, this part is subdivided into three chapters. Chapter One, entitled "Women in the Triangle: Martha and Margot," focuses on the two women characters in Nabokov’ s early novels. King, Queen, Knave and Laughter in the Dark, aiming to provide an in-depth analysis of the two, and to show that Nabokov has be stowed his special purpose on the creation of Martha and Margot, that is, his condemnation on those who reduce the free and active individual into objects, and such condemnation echoing with Nabokov’ s later direct vindication of individual freedom. Chapter Two, entitled "The Eternal Feminine:Lolita and Ada," analyzes the two title characters in Lolita and Ada, or Ardor:A Family Chronicle, illustrating that Lolita is the victim in that her free consciousness is purposefully neglected by the other, man in that case;while Ada enjoys her life totally because she can conduct her free consciousness in her own life. Chapter Three, entitled " Other Types and Women in His Mind’ s Eye," deals with Elisabeth, another woman character in Laughter in the Dark, who is a good traditional wife, and Liza, ex-wife of Pnin in Pnin, who is what Nabokov terms as poshlost. In addition, this chapter also provides an examination of Nabokov’ s attitude toward women. Through this analysis, Nabokov’ s Russian Complex is to a degree illustrated.

  5. Representing Chronic Disorders of Consciousness:

    Science.gov (United States)

    Hall, Alice

    2014-01-01

    This article explores problems of voicelessness in Isabel Allende’s Paula (1995) through a focus on the story of Paula’s illness and subsequent death from porphyria in 1992. I argue that the language, categories and stories through which disorders of consciousness are constructed are central to ethical decision-making and shifting cultural understandings of these conditions. In Paula, Allende uses an experimental, hybrid narrative form that draws on illness narrative, magical realist novel, national history, letters, and memoir to challenge traditional depictions of “coma” and to create a new public space through which these issues of voicelessness can be addressed. PMID:25055709

  6. A novel thermoelectric cooling device using Peltier modules for inducing local hypothermia of the spinal cord: the effect of local electrically controlled cooling for the treatment of spinal cord injuries in conscious rats.

    Science.gov (United States)

    Morizane, Kei; Ogata, Tadanori; Morino, Tadao; Horiuchi, Hideki; Yamaoka, Gotaro; Hino, Masayuki; Miura, Hiromasa

    2012-03-01

    We developed a novel thermoelectric cooling device using Peltier modules for the treatment of spinal cord injury in rats. The extracorporeal electrically cooling component was attached to the aluminum arched plate which was placed on the surface of the spinal cord after the contusion injury in the 11th thoracic spinal cord. During the hypothermic treatment, rats were awake and could move in the cage. Hind limb motor function, evaluated using a BBB scale, in the hypothermic animals (33°C for 48 h) was significantly higher than that in the normothermic animals from 2 weeks to 8 weeks after the injury.

  7. Science of consciousness and the hard problem

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, H.P.

    1996-05-22

    Quantum theory is essentially a rationally coherent theory of the interaction of mind and matter, and it allows our conscious thoughts to play a causally efficacious and necessary role in brain dynamics. It therefore provides a natural basis, created by scientists, for the science of consciousness. As an illustration it is explained how the interaction of brain and consciousness can speed up brain processing, and thereby enhance the survival prospects of conscious organisms, as compared to similar organisms that lack consciousness. As a second illustration it is explained how, within the quantum framework, the consciously experienced {open_quotes}I{close_quotes} directs the actions of a human being. It is concluded that contemporary science already has an adequate framework for incorporating causally efficacious experimential events into the physical universe in a manner that: (1) puts the neural correlates of consciousness into the theory in a well defined way, (2) explains in principle how the effects of consciousness, per se, can enhance the survival prospects of organisms that possess it, (3) allows this survival effect to feed into phylogenetic development, and (4) explains how the consciously experienced {open_quotes}I{close_quotes} can direct human behaviour.

  8. Intrinsic Awareness, the Fundamental State of Consciousness

    CERN Document Server

    Luo, Weili

    2011-01-01

    In an effort to simplify the complexity in the studies of consciousness, the author suggests to divide the conscious experiences into a fundamental state, the intrinsic awareness (IA), and functions of this fundamental state. IA does not depend on external environment, our sense organs, and our cognitions. This ground state of consciousness is timeless and irreducible to sub-constituents; therefore reductionism can apply neither to the analysis nor to the new theory of IA. The methodology for investigating IA is proposed and the relation between IA and the hard problem in consciousness proposed by Chalmers is discussed.

  9. Consciousness as a state of matter

    Science.gov (United States)

    Tegmark, Max

    2015-07-01

    I examine the hypothesis that consciousness can be understood as a state of matter, "perceptronium", with distinctive information processing abilities. I explore five basic principles that may distinguish conscious matter from other physical systems such as solids, liquids and gases: the information, integration, independence, dynamics and utility principles. This approach generalizes Giulio Tononi's integrated information framework for neural-network-based consciousness to arbitrary quantum systems, and provides interesting links to error-correcting codes and condensed matter criticality, as well as an interesting connections between the emergence of consciousness and the emergence of time. (For more technical details, see arXiv:1401.1219).

  10. Consciousness as a State of Matter

    CERN Document Server

    Tegmark, Max

    2014-01-01

    I examine the hypothesis that consciousness can be understood as a state of matter, "perceptronium", with distinctive information processing abilities. I explore five basic principles that may distinguish conscious matter from other physical systems such as solids, liquids and gases: the information, integration, independence, dynamics and utility principles. This approach generalizes Giulio Tononi's integrated information framework for neural-network-based consciousness to arbitrary quantum systems, and provides interesting links to error-correcting codes and condensed matter criticality, as well as an interesting connections between the emergence of consciousness and the emergence of time. (For more technical details, see arXiv:1401.1219).

  11. Consciousness and Attention: On sufficiency and necessity

    Directory of Open Access Journals (Sweden)

    Jeroen J A Van Boxtel

    2010-12-01

    Full Text Available Recent research has slowly corroded a belief that selective attention and consciousness are so tightly entangled that they cannot be individually examined. In this review, we summarize psychophysical and neurophysiological evidence for a dissociation between top-down attention and consciousness. The evidence includes recent findings that show subjects can attend to perceptually invisible objects. More contentious is the finding that subjects can become conscious of an isolated object, or the gist of the scene in the near absence of top-down attention; we critically re-examine the possibility of ‘complete’ absence of top-down attention. We also cover the recent flurry of studies that utilized independent manipulation of attention and consciousness. These studies have shown paradoxical effects of attention, including examples where top-down attention and consciousness have opposing effects, leading us to strengthen and revise our previous views. Neuroimaging studies with EEG, MEG and fMRI are uncovering the distinct neuronal correlates of selective attention and consciousness in dissociative paradigms. These findings point to a functional dissociation: attention as analyzer and consciousness as synthesizer. Separating the effects of selective visual attention from those of visual consciousness is of paramount importance to untangle the neural substrates of consciousness from those for attention.

  12. Closing in on the constitution of consciousness

    Directory of Open Access Journals (Sweden)

    Steven M. Miller

    2014-11-01

    Full Text Available The science of consciousness is a nascent and thriving field of research that is founded on identifying the minimally sufficient neural correlates of consciousness. However, I have argued that it is the neural constitution of consciousness that science seeks to understand and that there are no evident strategies for distinguishing the correlates and constitution of (phenomenal consciousness. Here I review this correlation/constitution distinction problem and challenge the existing foundations of consciousness science. I present the main analyses from a longer paper in press on this issue, focusing on recording, inhibition, stimulation and combined inhibition/stimulation strategies, including proposal of the Jenga analogy to illustrate why identifying the minimally sufficient neural correlates of consciousness should not be considered the ultimate target of consciousness science. Thereafter I suggest that while combined inhibition and stimulation strategies might identify some constitutive neural activities — indeed minimally sufficient constitutive neural activities — such strategies fail to identify the whole neural constitution of consciousness and thus the correlation/constitution distinction problem is not fully solved. Various clarifications, potential objections and related scientific and philosophical issues are also discussed and I conclude by proposing new foundational claims for consciousness science.

  13. Restoring Conscious Arousal During Focal Limbic Seizures with Deep Brain Stimulation.

    Science.gov (United States)

    Kundishora, Adam J; Gummadavelli, Abhijeet; Ma, Chanthia; Liu, Mengran; McCafferty, Cian; Schiff, Nicholas D; Willie, Jon T; Gross, Robert E; Gerrard, Jason; Blumenfeld, Hal

    2016-03-03

    Impaired consciousness occurs suddenly and unpredictably in people with epilepsy, markedly worsening quality of life and increasing risk of mortality. Focal seizures with impaired consciousness are the most common form of epilepsy and are refractory to all current medical and surgical therapies in about one-sixth of cases. Restoring consciousness during and following seizures would be potentially transformative for these individuals. Here, we investigate deep brain stimulation to improve level of conscious arousal in a rat model of focal limbic seizures. We found that dual-site stimulation of the central lateral nucleus of the intralaminar thalamus (CL) and the pontine nucleus oralis (PnO) bilaterally during focal limbic seizures restored normal-appearing cortical electrophysiology and markedly improved behavioral arousal. In contrast, single-site bilateral stimulation of CL or PnO alone was insufficient to achieve the same result. These findings support the "network inhibition hypothesis" that focal limbic seizures impair consciousness through widespread inhibition of subcortical arousal. Driving subcortical arousal function would be a novel therapeutic approach to some forms of refractory epilepsy and may be compatible with devices already in use for responsive neurostimulation. Multisite deep brain stimulation of subcortical arousal structures may benefit not only patients with epilepsy but also those with other disorders of consciousness.

  14. The Double-Consciousness of Du Bois & the "Mestiza Consciousness" of Anzaldua.

    Science.gov (United States)

    Martinez, Theresa A.

    2002-01-01

    Suggests that W.E.B. Du Bois' concept of the "double-consciousness" and Gloria Anzaldua's concept of the "mestiza consciousness" are significant forms of oppositional culture and consciousness. Asserts that their two concepts are linked and nuanced ideas that describe interlocking systems of oppression spanning two centuries and arguably binding…

  15. The Double-Consciousness of Du Bois & the "Mestiza Consciousness" of Anzaldua.

    Science.gov (United States)

    Martinez, Theresa A.

    2002-01-01

    Suggests that W.E.B. Du Bois' concept of the "double-consciousness" and Gloria Anzaldua's concept of the "mestiza consciousness" are significant forms of oppositional culture and consciousness. Asserts that their two concepts are linked and nuanced ideas that describe interlocking systems of oppression spanning two centuries…

  16. Renal effects of atriopeptin (AP) II in conscious SHR

    Energy Technology Data Exchange (ETDEWEB)

    Smits, J.F.; Debets, J.M.; Struyker-Boudier, H.A.; Daemen, M.J.

    1986-03-05

    Diuresis and natriuresis following APs has been suggested to depend upon increased renal blood flow (RBF). In a previous study, they found that APII infusions in conscious SHR decrease RBF. In this study, they report effects of APII on glomerular filtration rate (GFR) and renal excretory function in conscious SHR. Male SHR were equipped with arterial and venous catheters. Furthermore, a special catheter was implanted into the bladder to allow continuous urine sampling from conscious, freely moving rats. Animals were allowed at least 4 days to recover. In one group of SHR, APII (N=7) or saline (N=7) was infused to quantitate excretion of water, Na/sup +/, and K/sup +/. Two other groups of SHR (N=8 each) were infused with /sup 51/Cr-EDTA and /sup 125/I-PAH. GFR and renal plasma flow (ERPF) were calculated from urine and a mid-time plasma sample during APII or saline infusion. Following changes in infusion rates, urine from the first 5 min was discarded, after which a 10-min collection was made. APII (0.5-4 ..mu..g/kg/min) increased water, Na/sup +/ and K/sup +/ output maximally during 2 ..mu..g/kg/min. ERPF decreased from 10.7 +/- 1.1 ml/min to 7.9 +/- 0.5 ml/min. GFR did not change significantly. Filtration fraction increased from 24 +/- 1% to 33 +/- 2%. Fractional water excretion increased from 0.8 +/- 0.2% to 2.5 +/- 0.7%. Saline infusions did not affect renal function. The results indicate that in conscious SHR, APII causes diuresis and natriuresis which does not depend upon increased GFR, but, rather, upon a primary tubular effect.

  17. Music in disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Jens Dieter Rollnik

    2014-07-01

    Full Text Available This review presents an overview of the use of music therapy in neurological early rehabilitation of patients with coma and other disorders of consciousness (DOC such as unresponsive wakefulness syndrome (UWS or minimally conscious state (MCS. There is evidence that patients suffering from UWS show emotional processing of auditory information, such as listening to speech. Thus, it seems reasonable to believe that music listening – as part of an enriched environment setting – may be of therapeutic value in these patients. There is, however, a considerable lack of evidence. The authors strongly encourage further studies to evaluate the efficacy of music listening in patients with DOC in neurological early rehabilitation. These studies should consider a precise clinical definition and homogeneity of the patient cohort with respect to the quality (coma vs. UWS vs. MCS, duration (rather weeks to months than days and cause (traumatic vs. non-traumatic of DOC, a standardised intervention protocol, valid clinical outcome parameters over a longer observation period (weeks to months, monitoring of neurophysiological and vegetative parameters and, if available, neuroimaging to confirm diagnosis and to demonstrate responses and functional changes in the patients` brains.

  18. Defining and measuring environmental consciousness

    Directory of Open Access Journals (Sweden)

    Jiménez Sánchez, Manuel

    2010-09-01

    Full Text Available Based on a review of the main analytical approaches found in the literature, in this paper we establish a multidimensional and behaviour-oriented definition of environmental consciousness. We propose a method to operationalize this definition with the final aim of obtaining summary measures (or indexes of this phenomenon which can be applied to different social contexts and time periods. The data obtained from a survey on environmental attitudes and behaviour conducted in 2004 among Andalusians (Ecobarómetro de Andalucía 2004 is used as an empirical basis for the proposed operationalization. The resulting measures are then employed to identify social groups according to the diverse forms of their environmental consciousness and to explore their basic socio-demographic profiles

    A partir de las principales aproximaciones analíticas presentes en la literatura, en este trabajo establecemos una definición de conciencia ambiental multidimensional y orientada a la conducta; proponemos un método para su operacionalización con el objetivo de elaborar medidas sintéticas de este fenómeno en distintos contextos sociales. La operacionalización propuesta utiliza como base empírica los resultados del Ecobarómetro de Andalucía (EBA 2004. Los indicadores resultantes son utilizados seguidamente para identificar distintos grupos sociales según la naturaleza de su conciencia ambiental.

  19. On the character of consciousness

    Directory of Open Access Journals (Sweden)

    Arto eAnnila

    2016-03-01

    Full Text Available The human brain is a particularly demanding system to infer its nature from observations. Thus, there is on one hand plenty of room for theorizing and on the other hand a pressing need for a rigorous theory. We apply statistical mechanics of open systems to describe the brain as a hierarchical system in consuming free energy in least time. This holistic tenet accounts for cellular metabolism, neuronal signaling, cognitive processes all together or any other process by a formal equation of motion that extends down to the ultimate precision of one quantum of action. According to this general thermodynamic theory cognitive processes are no different by their operational and organizational principle from other natural processes. Cognition too will emerge and evolve along path-dependent and non-determinate trajectories by consuming free energy in least time to attain thermodynamic balance within the nervous system itself and with its surrounding systems. Specifically, consciousness can be ascribed to a natural process that integrates various neural networks for coherent consumption of free energy, i.e., for meaningful deeds. The whole hierarchy of integrated systems can be formally summed up to thermodynamic entropy. The holistic tenet provides insight to the character of consciousness also by acknowledging awareness in other systems at other levels of nature’s hierarchy.

  20. Embodied mind and phenomenal consciousness

    Directory of Open Access Journals (Sweden)

    Maria VENIERI

    2015-06-01

    Full Text Available In recent years, a central debate in the philosophy of mind and cognitive science concerns the role of the body in perception and cognition. For many contemporary philosophers, not only cognition but also perception is connected mainly with the brain, where the processing of input from the senses takes place; whereas for the proponents of ‘embodied cognition’ other aspects of the body beyond the brain, including the environment, play a constitutive role in cognitive processes. In terms of perception, a new theory has emerged which stresses percep‑ tion’s active character and claims that the embodied subject and the environment, with which it interacts, form a dynamic system. Supporters of ‘enactive perception’ such as Susan Hurley and Alva Noë maintain that the physical substrate or the supervenience basis of perceptual experience and phenomenal consciousness may include besides the brain and the nervous system other bodily and environmental features. Yet, it will be argued in this paper that the interaction between the subject and the environment forms a system of causal relations, so we can theoretically interfere in the causal chains and create hallucinations, which cannot be distinguished from veridical perception, or a virtual reality as in the film Matrix (1999. This kind of argument and its related thought experiments aim to stress the primacy of the brain in determining phenomenal states, and show that the body and certain interactions with the environment have a causal, but not a constitutive or essential role, in forming phenomenal consciousness.

  1. Interference Control Modulations Over Conscious Perception

    Directory of Open Access Journals (Sweden)

    Itsaso Colás

    2017-05-01

    Full Text Available The relation between attention and consciousness has been a controversial topic over the last decade. Although there seems to be an agreement on their distinction at the functional level, no consensus has been reached about attentional processes being or not necessary for conscious perception. Previous studies have explored the relation of alerting and orienting systems of attention and conscious perception, but the impact of the anterior executive attention system on conscious access remains unexplored. In the present study, we investigated the behavioral interaction between executive attention and conscious perception, testing control mechanisms both at stimulus-level representation and after error commission. We presented a classical Stroop task, manipulating the proportion of congruent and incongruent trials, and analyzed the effect of reactive and proactive control on the conscious perception of near-threshold stimuli. Reactive control elicited under high proportion congruent conditions influenced participants’ decision criterion, whereas proactive control elicited under low proportion congruent conditions was ineffective in modulating conscious perception. In addition, error commission affected both perceptual sensitivity to detect near-threshold information and response criterion. These results suggest that reactivation of task goals through reactive control strategies in conflict situations impacts decision stages of conscious processing, whereas interference control elicited by error commission impacts both perceptual sensitivity and decision stages of conscious processing. We discuss the implications of our results for the gateway hypothesis about attention and consciousness, as they showed that interference control (both at stimulus-level representation and after error commission can modulate the conscious access of near-threshold stimuli.

  2. Effects of hypertension on hemodynamic response and serum nitrite concentration during graded hemorrhagic shock in rats

    OpenAIRE

    Babak Barmaki; Ali Nasimi; Majid Khazaei

    2011-01-01

    Background: Hypertensive patients have higher morbidity and mortality from hemorrhage. In this study, we investigated hemodynamic responses and serum nitrite concentrations during graded hemorrhagic shock and resuscitation in hypertensive (HT) and normotensive (NT) rats. Methods: Thirteen male rats were divided into two groups, namely HT (n = 6) and NT (n = 7). Hypertension was induced by deoxycorticosterone acetate (DOCA)-salt method in uninephrectomized rats. After 8 weeks, graded hemor...

  3. Cold-Induced Thermogenesis and Inflammation-Associated Cold-Seeking Behavior Are Represented by Different Dorsomedial Hypothalamic Sites: A Three-Dimensional Functional Topography Study in Conscious Rats.

    Science.gov (United States)

    Wanner, Samuel P; Almeida, M Camila; Shimansky, Yury P; Oliveira, Daniela L; Eales, Justin R; Coimbra, Cândido C; Romanovsky, Andrej A

    2017-07-19

    In the past, we showed that large electrolytic lesions of the dorsomedial hypothalamus (DMH) promoted hypothermia in cold-exposed restrained rats, but attenuated hypothermia in rats challenged with a high dose of bacterial lipopolysaccharide (LPS) in a thermogradient apparatus. The goal of this study was to identify the thermoeffector mechanisms and DMH representation of the two phenomena and thus to understand how the same lesion could produce two opposite effects on body temperature. We found that the permissive effect of large electrolytic DMH lesions on cold-induced hypothermia was due to suppressed thermogenesis. DMH-lesioned rats also could not develop fever autonomically: they did not increase thermogenesis in response to a low, pyrogenic dose of LPS (10 μg/kg, i.v.). In contrast, changes in thermogenesis were uninvolved in the attenuation of the hypothermic response to a high, shock-inducing dose of LPS (5000 μg/kg, i.v.); this attenuation was due to a blockade of cold-seeking behavior. To compile DMH maps for the autonomic cold defense and for the cold-seeking response to LPS, we studied rats with small thermal lesions in different parts of the DMH. Cold thermogenesis had the highest representation in the dorsal hypothalamic area. Cold seeking was represented by a site at the ventral border of the dorsomedial nucleus. Because LPS causes both fever and hypothermia, we originally thought that the DMH contained a single thermoregulatory site that worked as a fever-hypothermia switch. Instead, we have found two separate sites: one that drives thermogenesis and the other, previously unknown, that drives inflammation-associated cold seeking.SIGNIFICANCE STATEMENT Cold-seeking behavior is a life-saving response that occurs in severe systemic inflammation. We studied this behavior in rats with lesions in the dorsomedial hypothalamus (DMH) challenged with a shock-inducing dose of bacterial endotoxin. We built functional maps of the DMH and found the strongest

  4. Music and Consciousness: A Continuing Project

    Science.gov (United States)

    Clarke, David; Clarke, Eric

    2014-01-01

    If there is a topic on which the humanities might make a distinctive claim, it is that of consciousness--an essential aspect of human being. And within the humanities, music might make its own claims in relation to both consciousness and being human. To investigate this connection, David Clarke and Eric Clarke brought together a wide variety of…

  5. Equation for Consciousness in terms of Physics

    Science.gov (United States)

    Kodukula, Siva Prasad

    2012-11-01

    Based on the concepts 'Double Relativity Effectí. 'Film theory of the Universe ','Heart of the God model of the universeí and'Space time equivalenceí, it is concluded that consciousness is defined in terms of physics as Çthe electromagnetic field containing electromagnetic waves of velocity greater than that of light velocity.? Also it is concluded that because of this high velocity the cell or any living organism will get the perception of events before their happenings. This phenomenon is one of the properties of feeling which is a constituent of consciousness. The degree or strength of consciousness can be measured and defined as the distance of point of generation of conscious wave from the center of space time fluid related to consciousness (d). It can be measured by the equation VCW3.d2= Constant. Where 'VCWí is the velocity of consciousness wave observed. The unit of measurement for degree or strength of consciousness is 'conscious meterí.

  6. Neural plasticity lessons from disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Athena eDemertzi

    2011-02-01

    Full Text Available Communication and intentional behavior are supported by the brain’s integrity at a structural and a functional level. When widespread loss of cerebral connectivity is brought about as a result of a severe brain injury, in many cases patients are not capable of conscious interactive behavior and are said to suffer from disorders of consciousness (e.g., coma, vegetative state /unresponsive wakefulness syndrome, minimally conscious states. This lesion paradigm has offered not only clinical insights, as how to improve diagnosis, prognosis and treatment, but also put forward scientific opportunities to study the brain’s plastic abilities. We here review interventional and observational studies performed in severely brain-injured patients with regards to recovery of consciousness. The study of the recovered conscious brain (spontaneous and/or after surgical or pharmacologic interventions, suggests a link between some specific brain areas and the capacity of the brain to sustain conscious experience, challenging at the same time the notion of fixed temporal boundaries in rehabilitative processes. Altered functional connectivity, cerebral structural reorganization as well as behavioral amelioration after invasive treatments will be discussed as the main indices for plasticity in these challenging patients. The study of patients with chronic disorders of consciousness may, thus, provide further insights not only at a clinical level (i.e., medical management and rehabilitation but also from a scientific-theoretical perspective (i.e., the brain’s plastic abilities and the pursuit of the neural correlate of consciousness.

  7. An Exploration of Jane Eyre's Feminist Consciousness

    Institute of Scientific and Technical Information of China (English)

    吴伊璐

    2013-01-01

    In the novel Jane Eyre,Jane's feminist consciousness can be divided into three stages which involve her lasting struggle for fundamental equality,economic Independence and freedom of love. Throughout Jane's lifetime,the author expressed the awakening of feminist consciousness which encouraged those traditional females to pursue gender equality of love and expressed concern about the liberation of women and thoughts.

  8. [Analytical problems of altered states of consciousness].

    Science.gov (United States)

    Frolov, M V

    1993-01-01

    Modified states of consciousness are created under the conditions of monotony with modulating influences in minute wave length diapason. These data point to an important role of the modulating system of the cerebral brain in consciousness the content of which is determined by informational processes.

  9. Music and Consciousness: A Continuing Project

    Science.gov (United States)

    Clarke, David; Clarke, Eric

    2014-01-01

    If there is a topic on which the humanities might make a distinctive claim, it is that of consciousness--an essential aspect of human being. And within the humanities, music might make its own claims in relation to both consciousness and being human. To investigate this connection, David Clarke and Eric Clarke brought together a wide variety of…

  10. An integrative view on consciousness and introspection

    DEFF Research Database (Denmark)

    Overgaard, Morten; Mogensen, Jesper

    2017-01-01

    The relation between first and higher order mental states is currently unknown. In particular, the relation between conscious experience and introspection is difficult as the same methods are used to investigate them. In order to make progress in the scientific understanding of consciousness...

  11. Neural plasticity lessons from disorders of consciousness.

    Science.gov (United States)

    Demertzi, Athena; Schnakers, Caroline; Soddu, Andrea; Bruno, Marie-Aurélie; Gosseries, Olivia; Vanhaudenhuyse, Audrey; Laureys, Steven

    2010-01-01

    Communication and intentional behavior are supported by the brain's integrity at a structural and a functional level. When widespread loss of cerebral connectivity is brought about as a result of a severe brain injury, in many cases patients are not capable of conscious interactive behavior and are said to suffer from disorders of consciousness (e.g., coma, vegetative state/unresponsive wakefulness syndrome, minimally conscious states). This lesion paradigm has offered not only clinical insights, as how to improve diagnosis, prognosis, and treatment, but also put forward scientific opportunities to study the brain's plastic abilities. We here review interventional and observational studies performed in severely brain-injured patients with regards to recovery of consciousness. The study of the recovered conscious brain (spontaneous and/or after surgical or pharmacologic interventions), suggests a link between some specific brain areas and the capacity of the brain to sustain conscious experience, challenging at the same time the notion of fixed temporal boundaries in rehabilitative processes. Altered functional connectivity, cerebral structural reorganization as well as behavioral amelioration after invasive treatments will be discussed as the main indices for plasticity in these challenging patients. The study of patients with chronic disorders of consciousness may, thus, provide further insights not only at a clinical level (i.e., medical management and rehabilitation) but also from a scientific-theoretical perspective (i.e., the brain's plastic abilities and the pursuit of the neural correlate of consciousness).

  12. Acting: An Altered State of Consciousness.

    Science.gov (United States)

    Scheiffele, Eberhard

    2001-01-01

    Uses notions from the field Psychology of Consciousness, including an explanation of how psychologists define and investigate Altered States of Consciousness (ASCs). Argues that actors routinely enter an ASC. Establishes acting as a way to enter an ASC and discusses why theater artists, educators, and advocates need to be aware of both the dangers…

  13. Altered States of Consciousness and Alcohol.

    Science.gov (United States)

    Jones, Ben Morgan; And Others

    This document contains the reports of research at a symposium on "Altered States of Consciousness and Alcohol." The participants primarily agreed that alcohol induces an altered state of consciousness similar to other drugs, but that this phenomenon has not been explicitly stated due to the current interest in newer and more novel drugs. The…

  14. George Herbert Mead on consciousness: antidote to Cartesian absurdities?

    DEFF Research Database (Denmark)

    Willert, Søren

    experience; it is shared by humans and subhuman animals alike; (2) consciousness of environmental experience; Mead names this consciousness aspect awareness; it is exclusively human; (3) the peculiar sensed qualities attaching to consciousness, equalling what is today named qualia. Descartes...

  15. The compatibility between sociological and cognitive neuroscientific ideas on consciousness: is a neurosociology of consciousness possible?

    Science.gov (United States)

    Shkurko, Yulia S

    2013-03-01

    This article considers the possibility of integrating sociological and cognitive neuroscience ideas on consciousness and developing a new research area: neurosociology of consciousnesses. Research was conducted taking into account the limited knowledge on consciousness produced in these disciplines and the necessity of finding ways to study the social roles concerning the neural correlates of consciousness. Applying several ideas on consciousness from these disciplines (intersubjectivity, close connection with collective forms representations, deriving awareness from the brain's processes, and so on), I show that it is difficult to reconcile the differences in the treatment of consciousness through the simple combination of the different ideas. The integration should be pursued in light of the neuroscientific findings concerning consciousness in different social contexts (role behavior, social interactions, and so on). In integrating the concepts, I predicted the role of time delay in conscious awareness in decision making, synchronization of neural oscillations under conscious perception, and the activations of certain brain zones in correspondence to different conscious cognitive processes for understanding in face-to-face situations. The study reveals that the optimal path for neurosociological research on consciousness is in its primary development without a rigid binding to either sociology or neuroscience.

  16. An introduction to the biology of consciousness.

    Science.gov (United States)

    Delacour, J

    1995-09-01

    This paper summarizes the main steps in a scientific study of consciousness. From a survey of the recent literature, it appears that: (1) there is a clear tendency to consider consciousness as a scientific object; (2) consistent subjective and objective descriptions of consciousness are possible; an intentional-modeling structure accounts for its main features; (3) from the evolutionary biology standpoint, conscious cognitive activities, as based on models of the self, the world and the alter-ego, have a functional value; (4) the material basis of consciousness can be clarified without recourse to new properties of the matter or to quantum physics. Current neurobiology, based on classical macrophysics, appears able to handle the problem. In this scope, the neurobiology of sleep-wakefulness and attention, and neuropsychology, have already achieved substantial advances.

  17. Volition and the Function of Consciousness

    Science.gov (United States)

    Lau, Hakwan C.

    What are the psychological functions that could only be performed consciously? People have intuitively assumed that many acts of volition are not influenced by unconscious information. These acts range from simple examples such as making a spontaneous motor movement, to higher cognitive control. How ever, the available evidence suggests that under suitable conditions, unconscious information can influence these behaviors and the underlying neural mechanisms. One possibility is that stimuli that are consciously perceived tend to yield strong signals in the brain, which makes us think that consciousness has the function of such strong signals. However, if we could create conditions where the stimuli could yield strong signals but not the conscious experience of perception, perhaps we would find that such stimuli are just as effective in influencing volitional be havior. Future studies that focus on clarifying this issue may tell us what the defining functions of consciousness are.

  18. Hypnosis phenomenology and the neurobiology of consciousness.

    Science.gov (United States)

    Rainville, Pierre; Price, Donald D

    2003-04-01

    Recent developments in the philosophical and neurobiological studies of consciousness provide promising frameworks to investigate the neurobiology of hypnosis. A model of consciousness phenomenology is described to demonstrate that the experiential dimensions characterizing hypnosis (relaxation and mental ease, absorption, orientation and monitoring, and self-agency) reflect basic phenomenal properties of consciousness. Changes in relaxation-mental ease and absorption, produced by standard hypnotic procedures, are further associated with changes in brain activity within structures critically involved in the basic representation of the body-self and the regulation of states of consciousness. The combination of experiential and modern brain imaging methods offers a unique perspective on hypnotic phenomena and provides new observations consistent with the proposition that hypnosis is an altered state of consciousness.

  19. Neurodynamics of Cognition and Consciousness

    CERN Document Server

    Perlovsky, Leonid I

    2007-01-01

    This book addresses dynamical aspects of brain functions and cognition. Experimental evidence in humans and other mammalians indicates that complex neurodynamics is crucial for the emergence of higher-level cognition and consciousness. Dynamical neural systems with encoding in limit cycle and non-convergent attractors have gained increasing popularity in the past decade. The role of synchronization, desynchronization, and intermittent synchronization on cognition has been studied extensively by various authors, in particular by authors contributing to the present volume. This volume gives an overview of recent advances in this interdisciplinary field of cognitive and computer science related to dynamics of cognition, including experimental studies, dynamical modelling and interpretation of cognitive experiments, and theoretical approaches. The following topics are covered in this book: spatio-temporal dynamics of neural correlates of higher-level cognition; dynamical neural memories, including continuous and ...

  20. Taming power: Generative historical consciousness.

    Science.gov (United States)

    Winter, David G

    2016-04-01

    Power is a necessary dimension of all human enterprises. It can inspire and illuminate, but it can also corrupt, oppress, and destroy. Therefore, taming power has been a central moral and political question for most of human history. Writers, theorists, and researchers have suggested many methods and mechanisms for taming power: through affiliation and love, intellect and reason, responsibility, religion and values, democratic political structures, and separation of powers. Historical examples and social science research suggest that each has some success, but also that each is vulnerable to being hijacked by power itself. I therefore introduce generative historical consciousness (GHC) as a concept and measure that might help to secure the benefits of power while protecting against its outrages and excesses. I conclude by discussing the role that GHC may have played in the peaceful resolution of the Cuban Missile Crisis of 1962.

  1. Conscious sedation: a dying practice?

    Science.gov (United States)

    Manickam, Palaniappan; Kanaan, Ziad; Zakaria, Khalid

    2013-07-28

    Sedation practices vary according to countries with different health system regulations, the procedures done, and local circumstances. Interestingly, differences in the setting in which the practice of gastroenterology and endoscopy takes place (university-based vs academic practice) as well as other systematic practice differences influence the attitude of endoscopists concerning sedation practices. Conscious sedation using midazolam and opioids is the current standard method of sedation in diagnostic and therapeutic endoscopy. Interestingly, propofol is a commonly preferred sedation method by endoscopists due to higher satisfaction rates along with its short half-life and thus lower risk of hepatic encephalopathy. On the other hand, midazolam is the benzodiazepine of choice because of its shorter duration of action and better pharmacokinetic profile compared with diazepam. The administration of sedation under the supervision of a properly trained endoscopist could become the standard practice and the urgent development of an updated international consensus regarding the use of sedative agents like propofol is needed.

  2. Making CSB + -Trees Processor Conscious

    DEFF Research Database (Denmark)

    Samuel, Michael; Pedersen, Anders Uhl; Bonnet, Philippe

    2005-01-01

    Cache-conscious indexes, such as CSB+-tree, are sensitive to the underlying processor architecture. In this paper, we focus on how to adapt the CSB+-tree so that it performs well on a range of different processor architectures. Previous work has focused on the impact of node size on the performance...... of the CSB+-tree. We argue that it is necessary to consider a larger group of parameters in order to adapt CSB+-tree to processor architectures as different as Pentium and Itanium. We identify this group of parameters and study how it impacts the performance of CSB+-tree on Itanium 2. Finally, we propose...... a systematic method for adapting CSB+-tree to new platforms. This work is a first step towards integrating CSB+-tree in MySQL’s heap storage manager....

  3. Consciousness and stereoscopic environmental imaging

    Science.gov (United States)

    Mason, Steve

    2014-02-01

    The question of human consciousness has intrigued philosophers and scientists for centuries: its nature, how we perceive our environment, how we think, our very awareness of thought and self. It has been suggested that stereoscopic vision is "a paradigm of how the mind works" 1 In depth perception, laws of perspective are known, reasoned, committed to memory from an early age; stereopsis, on the other hand, is a 3D experience governed by strict laws but actively joined within the brain―one sees it without explanation. How do we, in fact, process two different images into one 3D module within the mind and does an awareness of this process give us insight into the workings of our own consciousness? To translate this idea to imaging I employed ChromaDepth™ 3D glasses that rely on light being refracted in a different direction for each eye―colors of differing wavelengths appearing at varying distances from the viewer resulting in a 3D space. This involves neither calculation nor manufacture of two images or views. Environmental spatial imaging was developed―a 3D image was generated that literally surrounds the viewer. The image was printed and adhered to a semi-circular mount; the viewer then entered the interior to experience colored shapes suspended in a 3D space with an apparent loss of surface, or picture plane, upon which the image is rendered. By focusing our awareness through perception-based imaging we are able to gain a deeper understanding of how the brain works, how we see.

  4. Partial baroreceptor dysfunction and low plasma nitric oxide bioavailability as determinants of salt-sensitive hypertension: a reverse translational rat study

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Pérez, A.S.; López-Rodríguez, J.F.; Calvo-Turrubiartes, M.Z. [Integrative Physiology Laboratory, Department of Physiology and Biophysics, San Luis Potosí (Mexico); Saavedra-Alanís, V.M. [Molecular Biology Laboratory, Department of Biochemistry, San Luis Potosí (Mexico); Llamazares-Azuara, L. [Autonomous University of San Luis Potosí, Renal Laboratory, Faculty of Medicine, San Luis Potosí (Mexico); Rodríguez-Martínez, M. [Integrative Physiology Laboratory, Department of Physiology and Biophysics, San Luis Potosí (Mexico)

    2013-10-02

    This study determined whether clinical salt-sensitive hypertension (cSSHT) results from the interaction between partial arterial baroreceptor impairment and a high-sodium (HNa) diet. In three series (S-I, S-II, S-III), mean arterial pressure (MAP) of conscious male Wistar ChR003 rats was measured once before (pdMAP) and twice after either sham (SHM) or bilateral aortic denervation (AD), following 7 days on a low-sodium (LNa) diet (LNaMAP) and then 21 days on a HNa diet (HNaMAP). The roles of plasma nitric oxide bioavailability (pNOB), renal medullary superoxide anion production (RMSAP), and mRNA expression of NAD(P)H oxidase and superoxide dismutase were also assessed. In SHM (n=11) and AD (n=15) groups of S-I, LNaMAP-pdMAP was 10.5±2.1 vs 23±2.1 mmHg (P<0.001), and the salt-sensitivity index (SSi; HNaMAP−LNaMAP) was 6.0±1.9 vs 12.7±1.9 mmHg (P=0.03), respectively. In the SHM group, all rats were normotensive, and 36% were salt sensitive (SSi≥10 mmHg), whereas in the AD group ∼50% showed cSSHT. A 45% reduction in pNOB (P≤0.004) was observed in both groups in dietary transit. RMSAP increased in the AD group on both diets but more so on the HNa diet (S-II, P<0.03) than on the LNa diet (S-III, P<0.04). MAP modeling in rats without a renal hypertensive genotype indicated that the AD*HNa diet interaction (P=0.008) increases the likelihood of developing cSSHT. Translationally, these findings help to explain why subjects with clinical salt-sensitive normotension may transition to cSSHT.

  5. Influence of age, body mass index, and blood pressure on the carotid intima-media thickness in normotensive and hypertensive patients.

    Science.gov (United States)

    Honzikova, Natasa; Labrova, Ruzena; Fiser, Bohumil; Maderova, Eva; Novakova, Zuzana; Zavodna, Eva; Semrad, Borivoj

    2006-10-01

    We investigated whether body mass index and blood pressure have an additive influence on the carotid intima-media thickness (IMT). In 27 patients treated for hypertension (47.2+/-8.7 years) and 23 normotensive subjects (44.1+/-8.1 years), 24-h recording of blood pressure was performed. The carotid IMT was determined by ultrasonography and baroreflex sensitivity by a spectral method from 5-min recordings of blood pressure. Significant differences between hypertensive and normotensive subjects were observed for carotid IMT (0.60+/-0.08 vs. 0.51+/-0.07 mm; pmass index (pinfluenced by either age or body mass index. Baroreflex sensitivity decreased with age (pinfluence of age and body mass index on the development of carotid IMT is essential only in normotensive subjects. In hypertensive subjects the influence of blood pressure predominates, as documented by a comparison of the carotid IMT between hypertensive and normotensive subjects.

  6. Tritium excretion after intravenous administration of tritium labelled adrenaline and noradrenaline and digital vascular reactivity to adrenaline and noradrenaline in normotensive and labile hypertensive subjects.

    Science.gov (United States)

    De Guia, D; Mendlowitz, M; Vlachakis, N D; Gitlow, S E; Nissenbaum, M

    1980-01-01

    1. The 24-h urinary excretion of tritium after tritiated adrenaline administration and digital vascular reactivity to exogenously administered adrenaline and noradrenaline were measured in ten normotensive and in twenty-eight labile essential hypertensive subjects. Tritiated noradrenaline excretion and apparent noradrenaline secretion rate were also measured in ten and eleven of these subjects, respectively. 2. Despite overlapping, the mean 24-h tritium excretion after 3H-adrenaline administration as well as reactivity to adrenaline were significantly greater in the hypertensive than in the normotensive subjects, whether or not they had increased responsiveness to noradrenaline. Significant correlation, however, was observed between tritium excretion of adrenaline and reactivity to adrenaline in both labile hypertensive and normotensive subjects. These measurements were also both significantly correlated with percentage variability in systolic and diastolic blood pressure in the labile hypertensive subjects. 3. No significant correlation was observed between adrenaline as against noradrenaline measurements, whether physiological or biochemical, in either hypertensive or normotensive subjects.

  7. Effect of changes in dietary sodium and potassium on blood pressure and cellular electrolyte handling in young normotensive subjects.

    Science.gov (United States)

    Weissberg, P L; West, M J; Kendall, M J; Ingram, M; Woods, K L

    1985-10-01

    In a study on 22 normotensive male subjects, a change in dietary sodium intake from 29.6 +/- 6.0 to 332.5 +/- 13.9 mmol/day (mean +/- s.e.m.), over 7 days, was associated with a significant rise in supine and standing systolic blood pressure and a fall in sodium pump activity. Intracellular sodium remained constant, while intracellular potassium fell. These changes appeared to be reversed by the addition of potassium (96 mmol/day) to the high sodium diet. The 12 subjects with a family history of essential hypertension, as determined by measurement of parental blood pressure, did not differ in their response from those whose parents were normotensive.

  8. Effect of soy nuts on adhesion molecules and markers of inflammation in hypertensive and normotensive postmenopausal women.

    Science.gov (United States)

    Nasca, Melita M; Zhou, Jin-Rong; Welty, Francine K

    2008-07-01

    Recently, it was shown that substituting soy nuts for nonsoy protein in a therapeutic lifestyle change (TLC) diet lowered systolic and diastolic blood pressure by 9.9% and 6.8%, respectively, in postmenopausal women with hypertension and by 5.2% and 2.9%, respectively, in normotensive postmenopausal women. In this study, to examine mechanisms for these reductions, markers of inflammation were measured, including soluble vascular cell adhesion molecule-1, soluble intercellular adhesion molecule-1, C-reactive protein, interleukin-6, and matrix metalloproteinase-9. Sixty healthy postmenopausal women (48 normotensive and 12 with hypertension) were randomized in a crossover design to a TLC diet alone or a TLC diet in which 0.5 cups of soy nuts (25 g soy protein and 101 mg aglycone isoflavones) replaced 25 g of nonsoy protein daily. Each diet was followed for 8 weeks. Compared with the TLC diet alone, levels of soluble vascular cell adhesion molecule-1 were significantly lower on the soy diet in women with hypertension (623.6 +/- 153.8 vs 553.8 +/- 114.4 ng/ml, respectively, p = 0.003), whereas no significant differences were observed in normotensive women. Soy nuts were associated with a trend toward reduction in C-reactive protein in normotensive women. No effect on levels of soluble intercellular adhesion molecule-1, interleukin-6, or matrix metalloproteinase-9 was observed. In conclusion, the reduction in soluble vascular cell adhesion molecule-1 with soy nuts in women with hypertension suggests an improvement in endothelial function that may reflect an overall improvement in the underlying inflammatory process underlying atherosclerosis.

  9. The occurrence of left ventricular hypertrophy in normotensive individuals in a community setting in North-East Trinidad

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    Mungrue K

    2011-07-01

    Full Text Available Romel Bacchus, Kristianna Singh, Ijaz Ogeer, Kameel MungrueDepartment Paraclinical Sciences, Public Health and Primary Care Unit, Faculty of Medical Sciences, University of the West Indies, EWMSC, Mt Hope TrinidadObjective: The purpose of this study is to determine primarily the occurrence of left ventricular hypertrophy (LVH in normotensive Trinidadians.Design and methods: Enrolment into the study required participants to have normal blood pressure (≤140/90 using the JNC 7 (The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure classification, free of type 2 diabetes, as well as no existing LVH. Upon entry into the study, participants were first screened for LVH using a standard 12-lead electrocardiogram (ECG, using the Sokolow–Lyon index and the Cornell index. ECHO was used to confirm or refute the diagnosis of LVH.Results: A total of 209 patients met the criteria for entry into the study. Of these, 63.6% had LVH using Cornell criteria and 68.2% using LVH by Sokolow–Lyon criteria. Subsequently, ECHO confirmed the diagnosis in 2.9% using American Society of Echocardiography criteria and 1.5% using World Health Organization criteria. Thus the estimated prevalence of LVH in normotensive individuals was approximately 3%.Conclusion: The estimated prevalence of LVH in normotensive individuals appears to be relatively high if an ECG is the single investigation performed, which is common in our setting and may also be common in the developing world. However, using ECHO, the prevalence of LVH approaches a value similarly reported in the literature. Therefore, these findings raise two important issues: 1 the use of criteria such as the Cornell and Sokolow–Lyon voltage criteria established in the developed world from populations of vastly different ethnic backgrounds may not be widely applicable, and 2 all individuals suspected of having LVH should have an ECHO

  10. Effect of Soy Nuts on Adhesion Molecules and Markers of Inflammation in Hypertensive and Normotensive Postmenopausal Women

    Science.gov (United States)

    Nasca, Melita M.; Zhou, Jin-Rong; Welty, Francine K.

    2011-01-01

    Recently, we showed that substituting soy nuts for non-soy protein in a therapeutic lifestyle change (TLC) diet lowered systolic and diastolic blood pressure 9.9% and 6.8%, respectively, in hypertensive postmenopausal women and 5.2% and 2.9%, respectively, in normotensive postmenopausal women. To examine mechanisms for these reductions, we measured markers of inflammation including soluble vascular cell adhesion molecule (sVCAM-1), soluble intercellular adhesion molecule (sICAM-1), C-reactive protein (CRP), interleukin-6 (IL-6) and matrix metalloproteinase-9 (MMP-9). Sixty healthy postmenopausal women (48 normotensive and 12 hypertensive) were randomized in a crossover design to a TLC diet alone or a TLC diet in which one-half cup soy nuts (25 g soy protein and 101 mg aglycone isoflavones) replaced 25 g of non-soy protein daily. Each diet was followed for 8 weeks. Compared to the TLC diet alone, levels of sVCAM-1 were significantly lower on the soy diet in hypertensive women (623.6±153.8 ng/ml versus 553.8±114.4 ng/ml, respectively, p=0.003) whereas no significant differences were observed in normotensive women. Soy nuts were associated with a trend toward reduction in CRP in normotensive women. No effect on levels of sICAM-1, IL-6 or MMP-9 was observed. In conclusion, the reduction in sVCAM-1 with soy nuts in hypertensive women suggests an improvement in endothelial function which may reflect an overall improvement in the underlying inflammatory process underlying atherosclerosis. PMID:18572041

  11. A mathematical model of embodied consciousness.

    Science.gov (United States)

    Rudrauf, David; Bennequin, Daniel; Granic, Isabela; Landini, Gregory; Friston, Karl; Williford, Kenneth

    2017-09-07

    We introduce a mathematical model of embodied consciousness, the Projective Consciousness Model (PCM), which is based on the hypothesis that the spatial field of consciousness (FoC) is structured by a projective geometry and under the control of a process of active inference. The FoC in the PCM combines multisensory evidence with prior beliefs in memory and frames them by selecting points of view and perspectives according to preferences. The choice of projective frames governs how expectations are transformed by consciousness. Violations of expectation are encoded as free energy. Free energy minimization drives perspective taking, and controls the switch between perception, imagination and action. In the PCM, consciousness functions as an algorithm for the maximization of resilience, using projective perspective taking and imagination in order to escape local minima of free energy. The PCM can account for a variety of psychological phenomena: the characteristic spatial phenomenology of subjective experience, the distinctions and integral relationships between perception, imagination and action, the role of affective processes in intentionality, but also perceptual phenomena such as the dynamics of bistable figures and body swap illusions in virtual reality. It relates phenomenology to function, showing the computational advantages of consciousness. It suggests that changes of brain states from unconscious to conscious reflect the action of projective transformations and suggests specific neurophenomenological hypotheses about the brain, guidelines for designing artificial systems, and formal principles for psychology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Assessing levels of consciousness with symbolic analysis.

    Science.gov (United States)

    Lee, UnCheol; Blain-Moraes, Stefanie; Mashour, George A

    2015-02-13

    'Covert consciousness' is a state in which consciousness is present without the capacity for behavioural response, and it can occur in patients with intraoperative awareness or unresponsive wakefulness syndrome. To detect and prevent this undesirable state, it is critical to develop a reliable neurobiological assessment of an individual's level of consciousness that is independent of behaviour. One such approach that shows potential is measuring surrogates of cortical communication in the brain using electroencephalography (EEG). EEG is practicable in clinical application, but involves many fundamental signal processing problems, including signal-to-noise ratio and high dimensional complexity. Symbolic analysis of EEG can mitigate these problems, improving the measurement of brain connectivity and the ability to successfully assess levels of consciousness. In this article, we review the problem of covert consciousness, basic neurobiological principles of consciousness, current methods of measuring brain connectivity and the advantages of symbolic processing, with a focus on symbolic transfer entropy (STE). Finally, we discuss recent advances and clinical applications of STE and other symbolic analyses to assess levels of consciousness. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  13. Evaluation of left ventricular structures in normotensive and hypertensive subjects by two-dimensional echocardiography: Anthropometric correlates in hypertension

    Directory of Open Access Journals (Sweden)

    Mr. Agbo Julius Amaechi

    2008-07-01

    Full Text Available This study was conducted with the objective to establish a nomogram for some left ventricular structures and their alterations in hypertension. Correlations between left ventricular structures and anthropometric variables in hypertension were also established. A sample of 320 normotensive and 80 hypertensive subjects were studied. Echocardiograhic end diastolic diameter, posterior wall thickness and septal wall thickness were obtained. Subject height, weight, age and blood pressures were obtained. Blood pressures were measured in sitting position. The values of left ventricular mass (LVM, left ventricular mass index (LVMI and left relative wall thickness (RWT were computed. Parametric tests were conducted. Tests were two tailed with P < 0.05 indicating statistical significance. Normal values of left ventricular structures were established; LVM: 63.72g – 336.18g, LVMI: 38.16g/m – 222.64g/m, and RWT: 0.25 – 0.52. Significant differences (P < 0.05 were established in LVM, LVMI and RWT between normotensive and hypertensive subjects. Positive and significant correlations were noted between these variables and systolic blood pressure in hypertensive subjects. A simple linear regression of RWT on Body surface area gives RWT = - 0.058 BSA + 0.475 in normotensive subjects. Normal values of left ventricular structures and a linear regression model have been established which could be used in the assessment of morbidity in hypertension.

  14. Impediment of the progressions of microalbuminuria and hyperlipidemia in normotensive type 2 diabetes by low-dose ramipril.

    Science.gov (United States)

    Vongterapak, S; Dahlan, W; Nakasatien, S; Anuntakulnatee, T; Suppanich, M; Kittipoom, W; Surasingchaidet, C; Tamwiwat, C; Tepkasetkul, M; Bunnag, P; Ongphiphadhanakul, B; Rajatanavin, R; Himathongkam, T

    1998-09-01

    In a randomized, double-blind, placebo-controlled study, we investigated in normotensive type 2 diabetics with microalbuminuria the effect of ramipril, an ACE inhibitor, on urine albumin excretion and serum lipids. A total of 1,882 patients were screened for urine microalbumin consecutively by dipstick test, Rapi Tex-Albumin test and RIA. The final 28 normotensive and microalbuminuric patients were assigned to receive either ramipril (1.25 mg/d, n = 16) or placebo (n = 12) for 12 weeks. Throughout the study, both groups had no changes in blood pressure, fasting plasma glucose, HbA1C, serum creatinine and electrolytes and no difference in creatinine clearance. At week 12 only the placebo group showed the significant increment of urine albumin excretion and triacylglycerol (30.6 +/- 38.3 to 39.0 +/- 19.7 and 167 +/- 64 to 208 +/- 77 mg/dl, respectively) but the decrement of HDL-cholesterol (46 +/- 16 to 35 +/- 6 mg/dl). During a 3 month period, increased urine albumin excretion was observed in normotensive type 2 diabetes with microalbuminuria who received only placebo. We conclude that ramipril may arrest the progression of albumin excretion and had favorable effects on serum lipids. Ramipril was safe and well-tolerated without untoward side effects during the study period.

  15. Classification of high-risk with cardiac troponin and shock index in normotensive patients with pulmonary embolism.

    Science.gov (United States)

    Ozsu, Savas; Erbay, Muge; Durmuş, Zerrin Gürel; Ozlu, Tevfik

    2017-02-01

    Accurate risk stratification of normotensive patients with acute pulmonary embolism (PE) require further investigation. We aimed to develop a simple model using clinical (shock index) and laboratory findings (cardiac Troponin, echocardiography) to assess the risk of 30-day mortality in normotensive patients with acute PE. In this retrospective study, 489 normotensive patients with acute PE diagnosed objectively. The primary end-point was defined as a all cause 30-day mortality. Shock index was calculated on admission. The primary end-point occurred in 67 (13.7%, 95% CI 10.7-16.8) patients with acute PE. Predictors of complications included elevated cardiac troponin (OR 1.7, 95% CI 1.3-2.2) and shock index (OR 1.3, 95% CI 1.1-1.5) by multivariable analysis. Risk index point was created based on OR. The model identified stages (stage I: 0-1 point, stage II: 2 points and stage III: 3 point) with 30-day mortality rates of 4.3, 19 and 38.6 %, respectively. The shock index and cardiac troponin can be safely used in combination to determine intermediate risk in patients with PE in emergency departmant. The study provided observations that will require prospective validation before the proposed risk score is adopted in clinical practice.

  16. Effect of low-dose valsartan on proteinuria in normotensive immunoglobulin A nephropathy with minimal proteinuria: a randomized trial.

    Science.gov (United States)

    Jo, Young-Il; Na, Ha-Young; Moon, Ju-Young; Han, Sang-Woong; Yang, Dong-Ho; Lee, Sang-Ho; Park, Hyeong-Cheon; Choi, Hoon-Young; Lim, So-Dug; Kie, Jeong-Hae; Lee, Yong-Kyu; Shin, Sug-Kyun

    2016-03-01

    Immunoglobulin A nephropathy (IgAN) is a generally progressive disease, even in patients with favorable prognostic features. In this study, we aimed to investigate the antiproteinuric effect and tolerability of low-dose valsartan (an angiotensin II receptor blocker) therapy in normotensive IgAN patients with minimal proteinuria of less than 0.5 to 1.0 g/day. Normotensive IgAN patients, who had persistent proteinuria with a spot urine protein-to-creatinine ratio of 0.3 to 1.0 mg/mg creatinine, were recruited from five hospitals and randomly assigned to either 40 mg of valsartan as the low-dose group or 80 mg of valsartan as the regular-dose group. Clinical and laboratory data were collected at baseline, and at 4, 8, 12, and 24 weeks after valsartan therapy. Forty-three patients (low-dose group, n = 23; regular-dose group, n = 20) were enrolled in the study. Proteinuria decreased significantly not only in the regular-dose group but also in the low-dose group. The change in urine protein-to-creatinine ratio at week 24 was -41.3% ± 26.1% (p proteinuria without causing any intolerability in normotensive IgAN patients with minimal proteinuria.

  17. Conscious motor processing and movement self-consciousness: two dimensions of personality that influence laparoscopic training.

    Science.gov (United States)

    Malhotra, Neha; Poolton, Jamie M; Wilson, Mark R; Fan, Joe K M; Masters, Rich S W

    2014-01-01

    Identifying personality factors that account for individual differences in surgical training and performance has practical implications for surgical education. Movement-specific reinvestment is a potentially relevant personality factor that has a moderating effect on laparoscopic performance under time pressure. Movement-specific reinvestment has 2 dimensions, which represent an individual's propensity to consciously control movements (conscious motor processing) or to consciously monitor their 'style' of movement (movement self-consciousness). This study aimed at investigating the moderating effects of the 2 dimensions of movement-specific reinvestment in the learning and updating (cross-handed technique) of laparoscopic skills. Medical students completed the Movement-Specific Reinvestment Scale, a psychometric assessment tool that evaluates the conscious motor processing and movement self-consciousness dimensions of movement-specific reinvestment. They were then trained to a criterion level of proficiency on a fundamental laparoscopic skills task and were tested on a novel cross-handed technique. Completion times were recorded for early-learning, late-learning, and cross-handed trials. Propensity for movement self-consciousness but not conscious motor processing was a significant predictor of task completion times both early (p = 0.036) and late (p = 0.002) in learning, but completion times during the cross-handed trials were predicted by the propensity for conscious motor processing (p = 0.04) rather than movement self-consciousness (p = 0.21). Higher propensity for movement self-consciousness is associated with slower performance times on novel and well-practiced laparoscopic tasks. For complex surgical techniques, however, conscious motor processing plays a more influential role in performance than movement self-consciousness. The findings imply that these 2 dimensions of movement-specific reinvestment have a differential influence in the learning and updating

  18. Changes in blood pressure indices in normotensive adults after the consumption of lemongrass tea

    Institute of Scientific and Technical Information of China (English)

    Christopher Ekpenyong; Eme Osim

    2016-01-01

    Objective:To accurately evaluate the effect of lemongrasses tea (LGT) on blood pressure (BP) indices in normal humans. Methods:A total of 105 participants were sub-divided into 3 groups with 35 in each group and they were administered with LGT prepared from 2, 4 or 8 g of the lemongrass leaf powder (LP) for 30 days, respectively. They were evaluated for various BP indices and other clinical and biochemical parameters at days 0, 10 and 30 after the administration of LGT using standard methods. Results:At day 10, systolic blood pressure and diastolic blood pressure (DBP) were lower than baseline levels. The mean arterial pressure was slightly reduced, while pulse pressure and heart rate (HR) significantly increased in subjects administered with LGT prepared from 4 or 8 g of the LP. At day 30, systolic blood pressure and DBP remained decreased in participants administered with LGT prepared from 4 g of the LP. DBP normalized in participants administered with LGT prepared from 4 g of the LP. The mean arterial pressure and HR decreased further in participants administered with LGT prepared from 8 g of the LP, but HR normalized in subjects treated with LGT prepared from 4 g of the LP. Pulse pressure almost returned to baseline level. Conclusions:Ingestion of LGT may be associated with decreased BP indices in normotensive humans due to its varied bioactive constituents and their activities.

  19. Changes in blood pressure indices in normotensive adults after the consumption of lemongrass tea

    Directory of Open Access Journals (Sweden)

    Christopher Ekpenyong

    2016-10-01

    Full Text Available Objective: To accurately evaluate the effect of lemongrasses tea (LGT on blood pressure (BP indices in normal humans. Methods: A total of 105 participants were sub-divided into 3 groups with 35 in each group and they were administered with LGT prepared from 2, 4 or 8 g of the lemongrass leaf powder (LP for 30 days, respectively. They were evaluated for various BP indices and other clinical and biochemical parameters at days 0, 10 and 30 after the administration of LGT using standard methods. Results: At day 10, systolic blood pressure and diastolic blood pressure (DBP were lower than baseline levels. The mean arterial pressure was slightly reduced, while pulse pressure and heart rate (HR significantly increased in subjects administered with LGT prepared from 4 or 8 g of the LP. At day 30, systolic blood pressure and DBP remained decreased in participants administered with LGT prepared from 4 g of the LP. DBP normalized in participants administered with LGT prepared from 4 g of the LP. The mean arterial pressure and HR decreased further in participants administered with LGT prepared from 8 g of the LP, but HR normalized in subjects treated with LGT prepared from 4 g of the LP. Pulse pressure almost returned to baseline level. Conclusions: Ingestion of LGT may be associated with decreased BP indices in normotensive humans due to its varied bioactive constituents and their activities.

  20. Normotensive sepsis is associated with increased lipid peroxidation products in skeletal muscle

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    Lam, C.; Fox, G.; Neal, A.; Webb, C.; Rutledge, F.; Myers, M.; Sibbald, W. (Victoria Hospital/UWO, London, Ontario (Canada))

    1990-02-26

    Reactive oxygen species (ROS) have been implicated in the development of sepsis-induced multiple systems organ failure, possibly through biomembrane lipid perioxidation (BLP) which produces a loss of cell integrity and function. The authors examined the hypothesis that ROS activity contributes to non-pulmonary cell injury in hyperdynamic sepsis by measuring BLP products in skeletal muscle. The authors measured systemic flow (Q) by thermodilution and Q-gastrocnemius by the radioactive microsphere technique in 10 awake sheep, 48 hours following (i) the induction of hyperdynamic sepsis by cecal ligation and perforation or (ii) sham laparotomy. The animals were then anesthetized and biopsies from the gastrocnemius muscle were taken and flash frozen in liquid nitrogen for the determination of BLP products, which included conjugated dienes (CD), malondialdehyde (MDA), and acid-soluble sulfhydryls (SH). At the 48 hours study, Q was increased in the septic compared to the sham group while mean BP and Q-gastrocnemius were not different between the groups. Both CD and SH were significantly increased in the septic group. It was concluded that normotensive sepsis in this animal model produces evidence of increased ROS mediated BLP in non-pulmonary organs distant from the site of inflammation.

  1. Association between Salt Intake and Albuminuria in Normotensive and Hypertensive Individuals

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    Arsalan Khaledifar

    2013-01-01

    Full Text Available Background. There is a little published data regarding the association between salt intake and albuminuria as an important alarm for progression of cardiovascular and renal dysfunction. We aimed to assess this relationship to emphasize the major role of restricting salt intake to minimize albuminuria and prevent these life-threatening events. Methods. The study population comprised 820 individuals. Participants were assigned to groups as follows: normal albuminuria, slight albuminuria, and clinical albuminuria. Daily salt intake was assessed on the basis of 24-hour urinary sodium excretion, since urinary sodium excretion largely equals sodium intake. Results. In normotensive participants, the mean level of urine albumin was higher in those who had higher amounts of salt intake with a significantly upward trend (the mean urinary albumin level in low-salt-diet group, in medium-salt-intake group, and in high-salt-intake group was 42.70±36.42, 46.89±38.91, and 53.38±48.23, resp., (P=0.017. There was a significant positive correlation between 24-hour urinary sodium secretion and the level of urine albumin (beta = 0.130, P<0.001. The amount of salt intake was significantly associated with urine albumin concentration (beta = 3.969, SE = 1.671, P=0.018. Conclusion. High salt intake was shown to be associated with higher level of microalbuminuria even adjusted for potential underlying risk factors.

  2. How far cardio metabolic and psychological factors affect salt sensitivity in normotensive adult population?

    Science.gov (United States)

    Sadeghi, Masoumeh; Roohafza, Hamidreza; Pourmoghaddas, Masoud; Behnamfar, Omid; Pourmoghaddas, Zahra; Heidari, Ebrahim; Mahjoor, Zahra; Mousavi, Mehdi; Bahonar, Ahmad; Sarrafzadegan, Nizal

    2017-01-01

    AIM To evaluate the prevalence of salt sensitivity and the impact of cardiometabolic and psychological characteristics on salt sensitivity in normotensive population. METHODS Of all participants, anthropometric measurements and fasting venous blood samples were collected, and study questionnaires were completed. Salt Sensitivity was defined based on the difference in mean arterial pressure with infusion of 2 L of normal saline followed by a low sodium diet and administration of three doses of oral furosemide the day after. RESULTS Of 131 participants, 56 (42.7%) were diagnosed with salt sensitivity. Crude and age and sex adjusted regression analysis showed that low-density lipoprotein cholesterol and depression were positively associated with salt sensitivity (OR = 1.02, 95%CI: 1.01-1.04 and OR = 1.15, 95%CI: 1.00-1.34, respectively). CONCLUSION The high prevalence of salt sensitivity and its significant relation with prevalent risk factors necessitates considering its reduction actions at the population level and the need for further research. PMID:28163836

  3. The effect of nifedipine on renal function in normotensive cyclosporin-A-treated renal allograft recipients.

    Science.gov (United States)

    McNally, P G; Walls, J; Feehally, J

    1990-01-01

    Intrarenal vasoconstriction is a characteristic feature of CsA nephrotoxicity. The influence of nifedipine, a dihydropyridine calcium channel blocker and potent renal vasodilator, on renal haemodynamics was investigated in 11 cyclosporin A (CsA)- and 9 azathioprine (Aza)-treated normotensive long-term renal allograft recipients. Baseline Cr51-EDTA clearance and effective renal plasma flow (ERPF) were similar in both groups. Nifedipine 20 mg twice daily for 28 days significantly increased Cr51-EDTA clearance (+14.8%) in the CsA group; however, ERPF, renal vascular resistance (RVR), and filtration fraction did not change. Nifedipine did not influence renal haemodynamics in the azathioprine group. The increase in Cr51-EDTA clearance in the CsA group did not correlate with baseline renal function, CsA dose or whole blood levels, donor age, duration of graft, or renal functional reserve capacity. This study suggests that nifedipine confers a beneficial effect on renal haemodynamics in long-term CsA-treated renal allograft recipients and appears to improve renal function by a non-haemodynamic mechanism.

  4. A narrative method for consciousness research.

    Science.gov (United States)

    Díaz, José-Luis

    2013-01-01

    Some types of first-person narrations of mental processes that constitute phenomenological accounts and texts, such as internal monolog statements, epitomize the best expressions and representations of human consciousness available and therefore may be used to model phenomenological streams of consciousness. The type of autonomous monolog in which an author or narrator declares actual mental processes in a think aloud manner seems particularly suitable for modeling streams of consciousness. A narrative method to extract and depict conscious processes, operations, contents, and states from an acceptable phenomenological text would require three subsequent steps: operational criteria for producing and/or selecting a phenomenological text, a system for detecting text items that are indicative of conscious contents and processes, and a procedure for representing such items in formal dynamic system devices such as Petri nets. The requirements and restrictions of each of these steps are presented, analyzed, and applied to phenomenological texts in the following manner: (1) the relevance of introspective language and narrative analyses to consciousness research and the idea that specific narratives are of paramount interest for such investigation is justified; (2) some of the obstacles and constraints to attain plausible consciousness inferences from narrative texts and the methodological requirements to extract and depict items relevant to consciousness contents and operations from a suitable phenomenological text are examined; (3) a preliminary exercise of the proposed method is used to analyze and chart a classical interior monolog excerpted from James Joyce's Ulysses, a masterpiece of the stream-of-consciousness literary technique and, finally, (4) an inter-subjective evaluation for inter-observer agreement of mental attributions of another phenomenological text (an excerpt from the Intimate Journal of Miguel de Unamuno) is presented using some mathematical tools.

  5. A narrative method for consciousness research

    Directory of Open Access Journals (Sweden)

    José-Luis eDíaz

    2013-11-01

    Full Text Available Some types of first person narrations of mental processes that constitute phenomenological parliaments and texts, such as internal monologue statements, epitomize the best expressions and representations of human consciousness available and therefore may be used to model phenomenological streams of consciousness. The type of autonomous monologue in which an author or narrator declares actual mental processes in a think aloud manner seems particularly suitable for modeling streams of consciousness. A narrative method to extract and depict conscious processes, operations, contents, and states from an acceptable phenomenological text would require three subsequent steps: operational criteria for producing and/or selecting a phenomenological text, a system for detecting text items that are indicative of conscious contents and processes, and a procedure for representing such items in formal dynamic system devices such as Petri nets. The requirements and restrictions of each of these steps are presented, analyzed, and applied to phenomenological texts in the following manner: (1 The relevance of introspective language and narrative analyses to consciousness research and the idea that specific narratives are of paramount interest for such investigation is justified; (2 Some of the obstacles and constraints to attain plausible consciousness inferences from narrative texts and the methodological requirements to extract and depict items relevant to consciousness contents and operations from a suitable phenomenological text are examined; (3 A preliminary exercise of the proposed method is used to analyze and chart a classical interior monologue excerpted from James Joyce’s Ulysses, a masterpiece of the stream-of-consciousness literary technique and, finally, an inter-subjective evaluation for inter-observer agreement of mental attributions of another phenomenological text (an excerpt from the Intimate Journal of Miguel de Unamuno is presented using some

  6. Nonlinear analysis of renal autoregulation in rats using principal dynamic modes

    DEFF Research Database (Denmark)

    Marmarelis, V Z; Chon, K H; Holstein-Rathlou, N H

    1999-01-01

    and collected in normotensive and hypertensive rats for two levels of pressure forcing (as measured by the standard deviation of the pressure fluctuation). The PDMs are computed from first-order and second-order kernel estimates obtained from the data via the Laguerre expansion technique. The results...

  7. Quantum reality explains mystical powers of consciousness

    Directory of Open Access Journals (Sweden)

    Michael Mensky

    2014-11-01

    Full Text Available Mystical powers of consciousness, including the direct vision of truth and management a reality, are believed to exist. Various directions of spiritual knowledge, including world religions, deal with these phenomena. Many people are persuaded that mystical events cannot be explained by scientific methods, that they contradict to science. Suggested by the present author Quantum Concept of Consciousness, or Extended Everett Concept, proves that mystical powers have their origin from what is known in quantum mechanics as quantum reality, and therefore are inherent part of science. Therefore, the “mystical” aspect in the sphere of consciousness is a common part of science and spiritual knowledge.

  8. The cognitive approach to conscious machines

    CERN Document Server

    Haikonen, Pentti O

    2003-01-01

    Could a machine have an immaterial mind? The author argues that true conscious machines can be built, but rejects artificial intelligence and classical neural networks in favour of the emulation of the cognitive processes of the brain-the flow of inner speech, inner imagery and emotions. This results in a non-numeric meaning-processing machine with distributed information representation and system reactions. It is argued that this machine would be conscious; it would be aware of its own existence and its mental content and perceive this as immaterial. Novel views on consciousness and the mind-

  9. What about pain in disorders of consciousness?

    Science.gov (United States)

    Schnakers, C; Chatelle, C; Demertzi, A; Majerus, S; Laureys, S

    2012-09-01

    The management and treatment of acute pain is very difficult in non-communicative patients with disorders of consciousness (i.e., vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious state), creating an ethical dilemma for caregivers and an emotional burden among both relatives and caregivers. In this review, we summarize recent findings about the neural substrates of nociception and pain in VS/UWS patients as well as recent behavioral assessment methods of nociception specifically designed for patients in altered states of consciousness. We will finally discuss implications for pain treatment in these patients.

  10. HOW COULD CONSCIOUS EXPERIENCES AFFECT BRAINS?

    OpenAIRE

    Velmans, Professor Max

    2002-01-01

    In everyday life we take it for granted that we have conscious control of some of our actions and that the part of us that exercises control is the conscious mind. Psychosomatic medicine also assumes that the conscious mind can affect body states, and this is supported by evidence that the use of imagery, hypnosis, biofeedback and other ‘mental interventions’ can be therapeutic in a variety of medical conditions. However, there is no accepted theory of mind/body interaction and this has had...

  11. Can a machine be conscious? How?

    OpenAIRE

    Harnad, Stevan

    2003-01-01

    A "machine" is any causal physical system, hence we are machines, hence machines can be conscious. The question is: which kinds of machines can be conscious? Chances are that robots that can pass the Turing Test -- completely indistinguishable from us in their behavioral capacities -- can be conscious (i.e. feel), but we can never be sure (because of the "other-minds" problem). And we can never know HOW they have minds, because of the "mind/body" problem. We can only know how they pass the Tu...

  12. The "conscious pilot"-dendritic synchrony moves through the brain to mediate consciousness.

    Science.gov (United States)

    Hameroff, Stuart

    2010-01-01

    Cognitive brain functions including sensory processing and control of behavior are understood as "neurocomputation" in axonal-dendritic synaptic networks of "integrate-and-fire" neurons. Cognitive neurocomputation with consciousness is accompanied by 30- to 90-Hz gamma synchrony electroencephalography (EEG), and non-conscious neurocomputation is not. Gamma synchrony EEG derives largely from neuronal groups linked by dendritic-dendritic gap junctions, forming transient syncytia ("dendritic webs") in input/integration layers oriented sideways to axonal-dendritic neurocomputational flow. As gap junctions open and close, a gamma-synchronized dendritic web can rapidly change topology and move through the brain as a spatiotemporal envelope performing collective integration and volitional choices correlating with consciousness. The "conscious pilot" is a metaphorical description for a mobile gamma-synchronized dendritic web as vehicle for a conscious agent/pilot which experiences and assumes control of otherwise non-conscious auto-pilot neurocomputation.

  13. Science of the conscious mind.

    Science.gov (United States)

    Ascoli, Giorgio A; Samsonovich, Alexei V

    2008-12-01

    Human beings have direct access to their own mental states, but can only indirectly observe cosmic radiation and enzyme kinetics. Why then can we measure the temperature of far away galaxies and the activation constant of kinases to the third digit, yet we only gauge our happiness on a scale from 1 to 7? Here we propose a radical research paradigm shift to embrace the subjective conscious mind into the realm of objective empirical science. Key steps are the axiomatic acceptance of first-person experiences as scientific observables; the definition of a quantitative, reliable metric system based on natural language; and the careful distinction of subjective mental states (e.g., interpretation and intent) from physically measurable sensory and motor behaviors (input and output). Using this approach, we propose a series of reproducible experiments that may help define a still largely unexplored branch of science. We speculate that the development of this new discipline will be initially parallel to, and eventually converging with, neurobiology and physics.

  14. Consciousness as a State of Matter

    CERN Document Server

    Tegmark, Max

    2014-01-01

    We examine the hypothesis that consciousness can be understood as a state of matter, "perceptronium", with distinctive information processing abilities. We explore five basic principles that may distinguish conscious matter from other physical systems such as solids, liquids and gases: the information, integration, independence, dynamics and utility principles. If such principles can identify conscious entities, then they can help solve the quantum factorization problem: why do conscious observers like us perceive the particular Hilbert space factorization corresponding to classical space (rather than Fourier space, say), and more generally, why do we perceive the world around us as a dynamic hierarchy of objects that are strongly integrated and relatively independent? Tensor factorization of matrices is found to play a central role, and our technical results include a theorem about Hamiltonian separability (defined using Hilbert-Schmidt superoperators) being maximized in the energy eigenbasis. Our approach g...

  15. Industrial Application Of Environmentally Conscious Design

    DEFF Research Database (Denmark)

    McAloone, Timothy Charles

    This book is an adaptation of the author’s PhD thesis, in which he explored environmentally conscious design in the electrical/electronics industry sector. In this new and rapidly evolving field, existing research has not yet sought to understand the causes of success and the problems experienced...... when companies have integrated environmental considerations into the design process.In the context of advanced practitioners of environmentally conscious design in the Western European and North American electrical/electronics industry sector, it is shown that:- the timing of environmental decisions...... in the design process is key to environmentally conscious design;- the environmental profile of a product is affected the most in the very early stages of the design process, particularly in the pre-specification stage, where tools for environmentally conscious design decision-making are lacking...

  16. The merit of synesthesia for consciousness research

    Directory of Open Access Journals (Sweden)

    Tessa Marije Van Leeuwen

    2015-12-01

    Full Text Available Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant to identify the mental and physiological processes that subserve synesthetic experience. In the present work we suggest several reasons why synesthesia has merit for research on consciousness. We first review the research on the dynamic and rapidly growing field of the studies of synesthesia. We particularly draw attention to the role of semantics in synesthesia, which is important for establishing synesthetic associations in the brain. We then propose that the interplay between semantics and sensory input in synesthesia can be helpful for the study of the neural correlates of consciousness, especially when making use of ambiguous stimuli for inducing synesthesia. Finally, synesthesia-related alterations of brain networks and functional connectivity can be of merit for the study of consciousness.

  17. The merit of synesthesia for consciousness research

    NARCIS (Netherlands)

    Leeuwen, T.M. van; Singer, W.; Nikolic, D.

    2015-01-01

    Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant

  18. The Merit of Synesthesia for Consciousness Research.

    Science.gov (United States)

    van Leeuwen, Tessa M; Singer, Wolf; Nikolić, Danko

    2015-01-01

    Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant to identify the mental and physiological processes that subserve synesthetic experience. In the present work we suggest several reasons why synesthesia has merit for research on consciousness. We first review the research on the dynamic and rapidly growing field of the studies of synesthesia. We particularly draw attention to the role of semantics in synesthesia, which is important for establishing synesthetic associations in the brain. We then propose that the interplay between semantics and sensory input in synesthesia can be helpful for the study of the neural correlates of consciousness, especially when making use of ambiguous stimuli for inducing synesthesia. Finally, synesthesia-related alterations of brain networks and functional connectivity can be of merit for the study of consciousness.

  19. [Nursing education: integrating gender equity consciousness].

    Science.gov (United States)

    Tzeng, Ya-Ling; Shih, Hsin-Hsin; Yang, Ya-Ling

    2011-12-01

    Gender sensitivity influences the way a nurse handles the nursing process and can influence both patient care and public perception of the nursing profession. Nurses unaware of the influences of gender are unable to perform holistic nursing, the practice of which centers on patient-centered care. Education is essential to promote gender consciousness. Providing scenario-based education to apply gender consciousness can help nursing students integrate gender and nursing care concepts and improve nursing care quality. In addition to raising attention to this important issue, this article makes comprehensive suggestions on how to apply gender concepts in nursing education. These suggestions include requiring instructors to consider and assess their own gender consciousness in order to enhance positive gender consciousness; reviewing teaching materials to identify and remove content tainted by sexual discrimination, and emphasizing gender education in the nursing education curriculum.

  20. Mythology, Weltanschauung, symbolic universe and states of consciousness

    OpenAIRE

    2016-01-01

    This article investigates whether different religious (mythological) worldviews can be described as alternative and altered states of consciousness (ASCs). Differences between conscious and unconscious motivations for behaviour are discussed before looking at ASCs, Weltanschauung and symbolic universes. Mythology can be described both as Weltanschauung and symbolic universe, functioning on all levels of consciousness. Different Weltanschauungen constitute alternative states of consciousness. ...

  1. Tess's Female Consciousness in Tess of the D'Urbervilles

    Institute of Scientific and Technical Information of China (English)

    郭丽英

    2016-01-01

    Tess of the D'Urbervilles is the representative work of Thomas Hardy, an outstanding realistic writer in the nineteenth century's literary world. In his work, Hardy has created a new image filled with female consciousness,Tess. This paper just focuses on the study of Tess's female consciousness, from the following aspects: consciousness of self-reliance, consciousness of protest.

  2. Altered states of consciousness in small animals.

    Science.gov (United States)

    Platt, Simon

    2014-11-01

    Impaired states of consciousness can be relatively easily identified, although it can occasionally be difficult to assess whether there is a pure disorder of wakefulness or awareness. Regardless, such impairments represent dysfunction of the brainstem and or cerebrum. Acute and severe impairments of consciousness can require immediate assessment, in part currently performed using the modified Glasgow coma scoring system, and emergency stabilization. The prognosis is always guarded and highly sensitive to the underlying etiology. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Brain, conscious experience and the observing self

    DEFF Research Database (Denmark)

    Baars, Bernard J.; Ramsøy, Thomas; Laureys, Steven

    2003-01-01

    stimulus identification as such. What is the role of those regions? Parietal cortex support the 'first person perspective' on the visual world, unconsciously framing the visual object stream. Some prefrontal areas select and interpret conscious events for executive control. Such functions can be viewed...... as properties of the subject, rather than the object, of experience - the 'observing self' that appears to be needed to maintain the conscious state...

  4. The Merit of Synesthesia for Consciousness Research

    OpenAIRE

    van Leeuwen, Tessa M.; Singer, Wolf; Nikolić, Danko

    2015-01-01

    Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant to identify the mental and physiological processes that subserve synesthetic experience. In the present work we suggest several reasons why synesthesia has merit for research on consciousness. We ...

  5. George Herbert Mead on consciousness: antidote to Cartesian absurdities?

    DEFF Research Database (Denmark)

    Willert, Søren

    The article explicates George Herbert Mead's theory of consciousness as presented in Mind, Self and Society. According to Mead, the term consciousness may refer to three different sets of phenomena: (1) the environment as implied by our goal-directed action; Mead names this consciousness aspect...... experience; it is shared by humans and subhuman animals alike; (2) consciousness of environmental experience; Mead names this consciousness aspect awareness; it is exclusively human; (3) the peculiar sensed qualities attaching to consciousness, equalling what is today named qualia. Descartes......-inspired psychology makes the third consciousness aspect all-important. Within Mead's framework for a darwinistically inspired psycholgy, it becomes theoretically insignificant....

  6. The neurophysical basis of mind and consciousness

    Science.gov (United States)

    Beichler, James

    2012-04-01

    A living body is just a complex pattern of energetic particle exchanges to physicists when compared to the biochemical processes studied by chemists and biologists. New research has centered more upon the electric, magnetic and electromagnetic characteristics of life. It is easy to model mind and consciousness as the electric and magnetic counterparts of living organisms. Mind is an extremely complex electric scalar field pattern and consciousness is the corresponding magnetic vector potential field pattern. As humans, we may have the most complex and advanced mind and consciousness known, but all living organisms display mind and consciousness at various lower levels than our human mind and consciousness. Mind and consciousness have mistakenly become associated with the brain and no other part of the body because of the dense concentration of neurons in the brain. A strict study of the magnetic vector potential field patterns associated with neural microtubules, neurons and neural nets demonstrates how thoughts and streams of thought originate in the brain and are stored magnetically. Microtubules, which act as magnetic induction coils, are the primary structural bio-unit used for building, storing and retrieving memories in the mind.

  7. What kind of consciousness is minimal?

    Science.gov (United States)

    Kotchoubey, Boris; Vogel, Dominik; Lang, Simone; Müller, Friedemann

    2014-01-01

    A comparison between unitary and non-unitary views on minimal consciousness. First, unitary (all-or-none) and non-unitary (gradual or continuous) models of consciousness are defined as they have been developed in both philosophy and neurophysiology. Then, the implications of these ideas to the notion the minimally conscious state (MCS) are discussed. Review and analysis of theoretical conceptions and empirical data. Both kinds of models are compatible with the actual definitions of MCS. Although unitary views may seem to contradict the description of the MCS in 'Neurology' 2002, the apparent contradiction can easily be solved. Most recent data, particularly those obtained using fMRI and concerning learning, emotional responsiveness and pain and suffering, speak for non-unitary models. Most evidence speaks for non-unitary models of minimal consciousness. If these models are correct, patients with MCS may have, in addition to temporal fluctuations, a lower level of consciousness compared with fully conscious individuals. A still lower level could characterize patients diagnosed as unresponsive wakefulness syndrome (UWS). From this point of view, therefore, the difference between UWS and MCS is gradual rather than qualitative. However, due to methodological limitations of the available studies, the evidence for non-unitary models cannot be regarded as definite.

  8. The function of consciousness in multisensory integration.

    Science.gov (United States)

    Palmer, Terry D; Ramsey, Ashley K

    2012-12-01

    The function of consciousness was explored in two contexts of audio-visual speech, cross-modal visual attention guidance and McGurk cross-modal integration. Experiments 1, 2, and 3 utilized a novel cueing paradigm in which two different flash suppressed lip-streams cooccured with speech sounds matching one of these streams. A visual target was then presented at either the audio-visually congruent or incongruent location. Target recognition differed for the congruent versus incongruent trials, and the nature of this difference depended on the probabilities of a target appearing at these respective locations. Thus, even though the lip-streams were never consciously perceived, they were nevertheless meaningfully integrated with the consciously perceived sounds, and participants learned to guide their attention according to statistical regularities between targets and these unconsciously perceived cross-modal cues. In Experiment 4, McGurk stimuli were presented in which the lip-streams were either flash suppressed (4a) or unsuppressed (4b), and the McGurk effect was found to vanish under conditions of flash suppression. Overall, these results suggest a simple yet fundamental principle regarding the function of consciousness in multisensory integration - cross-modal effects can occur in the absence of consciousness, but the influencing modality must be consciously perceived for its information to cross modalities.

  9. Sleep neuroimaging and models of consciousness

    Directory of Open Access Journals (Sweden)

    Enzo eTagliazucchi

    2013-05-01

    Full Text Available Human deep sleep is characterized by reduced or absent sensory activity, responsiveness to stimuli and conscious awareness. Given its ubiquity and reversible nature, it represents an attractive paradigm to study the neural changes which accompany the loss of consciousness in humans. In particular, the deepest stages of sleep can serve as an empirical test for the predictions of theoretical models relating the phenomenology of consciousness with underlying neural activity. A relatively recent shift of attention from the analysis of evoked responses towards spontaneous (or ``resting state'' activity has taken place in the neuroimaging community, together with the development of tools suitable to study distributed functional interactions. In this review we focus on recent functional Magnetic Resonance Imaging (fMRI studies of spontaneous activity during sleep and their relationship with theoretical models for human consciousness generation, considering the global workspace theory, the information integration theory and the dynamical core hypothesis. We discuss the venues of research opened by these results, emphasizing the need to extend the analytic methodology in order to obtain a dynamical picture of how functional interactions change over time and how their evolution is modulated during different conscious states. Finally, we discuss the need to experimentally establish absent or reduced conscious content, even when studying the deepest sleep stages.

  10. Intuitive decisions on the fringes of consciousness

    Directory of Open Access Journals (Sweden)

    Mark C. Price

    2008-01-01

    Full Text Available Decision making research often dichotomises between more deliberative, cognitive processes and more heuristic, intuitive and emotional processes. We argue that within this two-systems framework (e.g., Kahneman, 2002 there is ambiguity over how to map the System 1/System 2 axis, and the notion of intuitive processing, onto the distinction between conscious and non-conscious processes. However the convergent concepts of experience-based metacognitive judgements (Koriat, 2007 and of fringe consciousness (Mangan, 1993 can clarify intuitive processing as an informative extit{conscious feeling} without conscious access to the antecedents of the feeling. We stress that these intuitive feelings can be used to guide behaviour in a controlled and contextually sensitive manner that would not be permitted by purely non-conscious influences on behaviour. An outline is provided for how to empirically recognise these intuitive feelings. This is illustrated with an example from research on implicit learning where intuitive feelings may play an important role in peoples' decisions and judgements. Finally we suggest that our approach to understanding intuitive feelings softens rather than reinforces the two-systems dichotomy.

  11. [Recovery of consciousness: process-oriented approach].

    Science.gov (United States)

    Gusarova, S B

    2014-01-01

    Traditionally psychological neurorehabilitation of neurosurgical patients is provided subject to availability of clear consciousness and minimal potential to communicate verbally. Cognitive and emotional disorders, problems in social adaptation, neurotic syndromes are normally targets in such cases. We work with patients having survived severe brain damage being in different states of consciousness: vegetative state, minimal state of consciousness, mutism, confusion, posttraumatic Korsaroff syndrom. Psychologist considers recovery of consciousness as the target besides traditional tasks. Construction of communication with patient is central part of such job, where the patient remains unable to contact verbally, yet it is impossible to consider potential aphasia. This is a non-verbal "dialogue" with patient created by psychologist with gradual development and involving other people and objects of environment. Inline with modern neuroscientific achievements demonstrating ability to recognize by patients with severe brain injury (A. Owen, S. Laureys, M. Monti, M. Coleman, A. Soddu, M. Boly and others) we base upon psychological science, on psychotherapeutic approaches containing instruments inevitable to work with patients in altered states of consciousness and creation of non-verbal communication with patient (Jung, Reich, Alexander, Lowen, Keleman, Arnold and Amy Mindell, S. Tomandl, D. Boadella, A. Längle, P. Levin etc). This article will include 15 years of experience to apply Process-oriented approach by A. Mindell to recovery of consciousness of neurosurgical patients based on work with "minimal signals" (micro moves, breath, mimic reactions etc.), principle of feedback, psychosomatic resonance, empathy.

  12. Is Your Gut Conscious? Is an Extraterrestrial?

    Science.gov (United States)

    Vos Post, Jonathan

    2011-10-01

    This paper speculates on questions intending to be taken scientifically rather than metaphysically: "Can the human gut (enteric nervous system) be conscious?"; "Can your immune system think?"; "Could consciousness be coded in DNA?"; "What do we mean when asserting that an Extraterrestrial is Thinking, or is Conscious? We explore through reference to theory, experiment, and computational models by Christof Koch (Caltech), Barbara Wold (Caltech), and Stuart Kauffman (University of Calgary, Tampere University of Technology, Santa Fe Institute). We use a tentative new definition of thinking, designed to be applicable for humans, cetecea, corvids, artificial intelligences, and extraterrestrial intelligences of any substrate (i.e. Life as We Do Not Know It): "Thinking is the occurrence, transformation, and storage in a mind or brain (or simulation thereof) of information-bearing structures (representations) of one kind or another, such as thoughts, concept, percepts, ideas, impressions, notions, rules, schemas, images, phantasms, or subpersonal representations." We use the framework for Consciousness developed by Francis Crick and Christof Koch. We try to describe scientific goals, but discuss Philosophy sufficient to avoid naïve philosophical category errors (thus are careful not to conflate thought, consciousness, and language) Penrose, Hameroff, and Kauffman speculate (differently) that CNS consciousness is a macroscopic quantum phenomenon. Might intestinal, immune system, or genetic regulatory network dynamics exhibit emergent cooperative quantum effects? The speculations are in the context of Evolution by Natural Selection, presumed to operate throughout the Cosmos, and recent work in the foundations of Computational Biology and Quantum Mechanics.

  13. Antihypertensive responses elicited by central moxonidine in rats: possible role of nitric oxide.

    Science.gov (United States)

    Moreira, Thiago Santos; Takakura, Ana Carolina Thomaz; Sato, Monica Akemi; Menani, José Vanderlei; Colombari, Eduardo

    2006-06-01

    In the present study, we investigated the effects of pretreatment with NG-nitro-L-arginine methyl ester (L-NAME) (nitric oxide synthase inhibitor) injected intravenously (IV) on the hypotension, bradycardia, and vasodilation produced by moxonidine (alpha2-adrenergic/imidazoline receptor agonist) injected into the fourth brain ventricle (4th V) in rats submitted to acute hypertension that results from baroreflex blockade by bilateral injections of kynurenic acid (kyn, glutamatergic receptor antagonist) into the nucleus of the solitary tract (NTS) or in normotensive rats. Male Wistar rats (n=5 to 7/group) anesthetized with IV urethane (1.0 g kg(-1) of body weight) and alpha-chloralose (60 mg kg(-1) of body weight) were used. Bilateral injections of kyn (2.7 nmol 100 nL(-1)) into the NTS increased baseline mean arterial pressure (148 +/- 11 mm Hg, vs. control: 102 +/- 4 mm Hg) and baseline heart rate (417 +/- 11 bpm, vs. control: 379 +/- 6 bpm). Moxonidine (20 nmol microL(-1)) into the 4th V reduced mean arterial pressure and heart rate to similar levels in rats treated with kyn into the NTS (68 +/- 9 mm Hg and 359 +/- 7 bpm) or in control normotensive rats (66 +/- 7 mm Hg and 362 +/- 8 bpm, respectively). The pretreatment with L-NAME (25 micromol kg, IV) attenuated the hypotension produced by moxonidine into the 4th V in rats treated with kyn (104 +/- 6 mm Hg) or in normotensive rats (95 +/- 8 mm Hg), without changing bradycardia. Moxonidine into the 4th V also reduced renal, mesenteric, and hindquarter vascular resistances in rats treated or not with kyn into the NTS and the pretreatment with L-NAME IV reduced these effects of moxonidine. Therefore, these data indicate that nitric oxide mechanisms are involved in hypotension and mesenteric, renal, and hindquarter vasodilation induced by central moxonidine in normotensive and in acute hypertensive rats.

  14. Neurotoxicity and toxicokinetics of norfloxacin in conscious rats%诺氟沙星在清醍大鼠的神经毒性和毒代动力学

    Institute of Scientific and Technical Information of China (English)

    张莉蓉; 王永铭; 陈斌艳; 程能能

    2003-01-01

    目的:研究诺氟沙星(norfloxacin,NFLX)在清醒大鼠的神经毒性和毒代动力学.方法:大鼠随机分为4组,分别ivNS,NFLX 50,100和200 mg/kg.连续记录自由活动大鼠的脑电图(EEG).用微生物法测定血清中NFLX浓度,检测菌为大肠杆菌441102.结果:(1)NFLX各组大鼠均出现痫样放电,并伴有局部抽搐、全身强直痉挛发作的行为学改变,呈剂量依赖性.脑电相对总功率增加(P<0.05).(2)NFLX的药时曲线符合二室模型,CL,Vc和T1/2β与给药剂量无关,Cmax和AUC0→∞呈剂量依赖性.(3)脑电总功率的增加与剂量、Cmax和AUCo→∞呈正相关(r分别为0.88,0.92,0.94).结论:本研究为量化诺氟沙星的中枢兴奋作用提供了可行的方法,与AUC0→∞相关的脑电相对总功率的变化可作为中枢毒性效应判定和预测的一项客观指标.%AIM: To study the neurotoxicity and toxicokinetics of norfloxacin (NFLX) in freely moving rats. METHODS:Rats were assigned randomly to four treatment groups that received a single iv dose of 50, 100, 200 mg/kg ofNFLX and 0.9 % saline, respectively. Electroencephalogram (EEG) was continuously recorded with a computer-ized system in freely moving rats. Venous blood samples were collected for determination of the NFLX concentra-tion by microbioassay method with Escherichia coli 441102 as the test strain. Toxicokinetic parameters weredetermined from serum concentration-time data with the 3p97 program. RESULTS: (1) The epileptiform dis-charges appeared in all NFLX groups with different latent periods, accompanied with limb twitching and clonic-tonic seizures. The relative total power of the EEG increased. (2) Drug serum concentration-time curves ofdifferent doses conformed to a two-compartmental model. The values of clearance, volume of distribution, andterminal half-life were dose-independent, while maximum serum concentrations (Cmax) and the areas under theconcentration-time curve (AUC0→∞) of NFLX increased with dosage. (3

  15. Gestation dependant changes in angiogenic factors and their associations with fetal growth measures in normotensive pregnancy.

    Directory of Open Access Journals (Sweden)

    Deepali Sundrani

    Full Text Available BACKGROUND: Earlier studies indicate that altered angiogenesis at birth is associated with poor birth outcome in women with preeclampsia. Now, we hypothesize that the progressive gestation dependant changes in markers of angiogenesis will be more useful to predict birth weight early even in a normotensive pregnancy. This study for the first time examines the association of gestation dependant changes in the levels of maternal angiogenic factors in addition to their levels in cord with birth weight. METHOD: Ninety two pregnant women were followed at three different time points: 16-20 weeks, 26-30 weeks and at delivery during pregnancy. Plasma levels of angiogenic and anti angiogenic factors were determined by commercial enzyme-linked immunosorbent assay (ELISA kits. RESULTS: Maternal plasma VEGF levels increased (p<0.01 till the second time point and decreased (p<0.05 up to delivery while plasma sFlt-1 levels increased (p<0.01 at delivery. PlGF levels peaked (p<0.01 at second time point and decreased (p<0.01 at delivery. Cord plasma VEGF levels were higher (p<0.01 and sFlt-1 levels were lower (p<0.01 as compared to maternal values at all time points. Maternal plasma VEGF levels at first time point and PlGF levels at delivery were positively (p<0.05 and p<0.01 respectively, while sFlt-1/PlGF ratio at delivery was negatively associated (p<0.05 with birth weight. CONCLUSION: Levels of pro- and anti-angiogenic factors may be differentially regulated across gestation. Maternal VEGF levels at early gestation (16-20 weeks may be predictive of birth weight in healthy term pregnancies.

  16. ECG is an inefficient screening-tool for left ventricular hypertrophy in normotensive African children population

    Directory of Open Access Journals (Sweden)

    Giuseppe Di Gioia

    2016-09-01

    Full Text Available Background Left ventricular hypertrophy (LVH is a marker of pediatric hypertension and predicts development of cardiovascular events. Electrocardiography (ECG screening is used in pediatrics to detect LVH thanks to major accessibility, reproducibility and easy to use compared to transthoracic echocardiography (TTE, that remains the standard technique. Several diseases were previously investigated, but no data exists regarding our study population. The aim of our study was to evaluate the relationship between electrocardiographic and echocardiographic criteria of LVH in normotensive African children. Methods We studied 313 children (mean age 7,8 ± 3 yo, in north-Madagascar. They underwent ECG and TTE. Sokolow-Lyon index was calculated to identify ECG-LVH (>35 mm. Left ventricle mass (LVM with TTE was calculated and indexed by height2.7 (LVMI2.7 and weight (LVMIw. We report the prevalence of TTE-LVH using three methods: (1 calculating percentiles age- and sex- specific with values >95th percentile identifying LVH; (2 LVMI2.7 >51 g/m2.7; (3 LVMIw >3.4 g/weight. Results 40 (13% children showed LVMI values >95th percentile, 24 children (8% an LVMI2.7 >51 g/m2.7 while 19 children (6% an LVMIw >3.4 g/kg. LVH-ECG by Sokolow-Lyon index was present in five, three and three children respectively, with poor values of sensitivity (ranging from 13 to 16%, positive predictive value (from 11 to 18% and high values of specificity (up to 92%. The effects of anthropometrics parameters on Sokolow-Lyon were analyzed and showed poor correlation. Conclusion ECG is a poor screening test for detecting LVH in children. In clinical practice, TTE remains the only tool to be used to exclude LVH.

  17. Systemic and regional hemodynamic effects of enalaprilat infusion in experimental normotensive sepsis

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    L. Rahal

    Full Text Available Angiotensin-converting enzyme inhibitors have been shown to improve splanchnic perfusion in distinct shock states. We hypothesized that enalaprilat potentiates the benefits of early fluid resuscitation in severe experimental sepsis, particularly in the splanchnic region. Anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live Escherichia coli over a period of 30 min. Thereafter, two interventions were performed: fluid infusion (normal saline, 32 mL/kg over 30 min and enalaprilat infusion (0.02 mg kg-1 min-1 for 60 min in randomized groups. The following groups were studied: controls (fluid infusion, N = 4, E1 (enalaprilat infusion followed by fluid infusion, N = 5 and E2 (fluid infusion followed by enalaprilat infusion, N = 5. All animals were observed for a 120 min after bacterial infusion. Mean arterial pressure, cardiac output (CO, portal vein blood flow (PVBF, systemic and regional oxygen-derived variables, and lactate levels were measured. Rapid and progressive reductions in CO and PVBF were induced by the infusion of live bacteria, while minor changes were observed in mean arterial pressure. Systemic and regional territories showed a significant increase in oxygen extraction and lactate levels. Widening venous-arterial and portal-arterial pCO2 gradients were also detected. Fluid replacement promoted transient benefits in CO and PVBF. Enalaprilat after fluid resuscitation did not affect systemic or regional hemodynamic variables. We conclude that in this model of normotensive sepsis inhibition of angiotensin-converting enzyme did not interfere with the course of systemic or regional hemodynamic and oxygen-derived variables.

  18. Post-plyometric exercise hypotension and heart rate in normotensive individuals: influence of exercise intensity.

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    Arazi, Hamid; Asadi, Abbas; Rahimzadeh, Mehdi; Moradkhani, Amir-Hossein

    2013-12-01

    The purpose of this study was to compare the effects of high, moderate and low intensity plyometric exercise on the post-exercise systolic and diastolic blood pressure and heart rate responses. Ten healthy normotensive men (age, 21.1±0.9 years; height, 175.8±6 cm; and body mass, 69.1±13.6 kg) volunteered to participate in this study and were evaluated for three non-consecutive days in depth jump exercise from 20-cm box (low intensity [LI]), 40-cm box (moderate intensity [MI]) and 60-cm box (high intensity [HI]) for 5 sets of 20 repetitions. After each exercise session, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured every 10 min for a period of 90 min. No significant differences were observed among post-exercise SBP, DBP and HR when the protocols (LI, MI and HI) were compared. The LI and HI protocols showed greater reduction in SBP at 40(th)-70(th) min of post-exercise (~9%), whereas the LI and MI protocols indicated greater reduction in DBP at 10(th)-50(th) min of post exercise (~10%). In addition, the change in the DBP for HI was not significant and the increases in the HR were similar for all intensities. It can be concluded that a plyometric exercise (PE) can reduce SBP and DBP post-exercise and therefore we can say that PE has significant effects for reducing BP and HR or post-exercise hypotension.

  19. Dietary Sodium Consumption Predicts Future Blood Pressure and Incident Hypertension in the Japanese Normotensive General Population.

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    Takase, Hiroyuki; Sugiura, Tomonori; Kimura, Genjiro; Ohte, Nobuyuki; Dohi, Yasuaki

    2015-07-29

    Although there is a close relationship between dietary sodium and hypertension, the concept that persons with relatively high dietary sodium are at increased risk of developing hypertension compared with those with relatively low dietary sodium has not been studied intensively in a cohort. We conducted an observational study to investigate whether dietary sodium intake predicts future blood pressure and the onset of hypertension in the general population. Individual sodium intake was estimated by calculating 24-hour urinary sodium excretion from spot urine in 4523 normotensive participants who visited our hospital for a health checkup. After a baseline examination, they were followed for a median of 1143 days, with the end point being development of hypertension. During the follow-up period, hypertension developed in 1027 participants (22.7%). The risk of developing hypertension was higher in those with higher rather than lower sodium intake (hazard ratio 1.25, 95% CI 1.04 to 1.50). In multivariate Cox proportional hazards regression analysis, baseline sodium intake and the yearly change in sodium intake during the follow-up period (as continuous variables) correlated with the incidence of hypertension. Furthermore, both the yearly increase in sodium intake and baseline sodium intake showed significant correlations with the yearly increase in systolic blood pressure in multivariate regression analysis after adjustment for possible risk factors. Both relatively high levels of dietary sodium intake and gradual increases in dietary sodium are associated with future increases in blood pressure and the incidence of hypertension in the Japanese general population. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  20. Enhanced assymetrical noradrenergic transmission in the olfactory bulb of deoxycorticosterone acetate-salt hypertensive rats.

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    Abramoff, Tamara; Guil, María J; Morales, Vanina P; Hope, Sandra I; Soria, Celeste; Bianciotti, Liliana G; Vatta, Marcelo S

    2013-10-01

    The ablation of olfactory bulb induces critical changes in dopamine, and monoamine oxidase activity in the brain stem. Growing evidence supports the participation of this telencephalic region in the regulation blood pressure and cardiovascular activity but little is known about its contribution to hypertension. We have previously reported that in the olfactory bulb of normotensive rats endothelins enhance noradrenergic activity by increasing tyrosine hydroxylase activity and norepinephrine release. In the present study we sought to establish the status of noradrenergic activity in the olfactory bulb of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Different steps in norepinephrine transmission including tyrosine hydroxylase activity, neuronal norepinephrine release and uptake were assessed in the left and right olfactory bulb of DOCA-salt hypertensive rats. Increased tyrosine hydroxylase activity, and decreased neuronal norepinephrine uptake were observed in the olfactory bulb of DOCA-salt hypertensive rats. Furthermore the expression of tyrosine hydroxylase and its phosphorylated forms were also augmented. Intriguingly, asymmetrical responses between the right and left olfactory bulb of normotensive and hypertensive rats were observed. Neuronal norepinephrine release was increased in the right but not in the left olfactory bulb of DOCA-salt hypertensive rats, whereas non asymmetrical differences were observed in normotensive animals. Present findings indicate that the olfactory bulb of hypertensive rats show an asymmetrical increase in norepinephrine activity. The observed changes in noradrenergic transmission may likely contribute to the onset and/or progression of hypertension in this animal model.