Intrinsic Heart Rate
Mostrando 13-24 de 41 artigos, teses e dissertações.
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13. Effect of acute nitric oxide synthase inhibition in the modulation of heart rate in rats
Acute nitric oxide synthase inhibition with N G-nitro-L-arginine methyl ester (L-NAME) on chronotropic and pressor responses was studied in anesthetized intact rats and rats submitted to partial and complete autonomic blockade. Blood pressure and heart rate were monitored intra-arterially. Intravenous L-NAME injection (7.5 mg/kg) elicited the same hypertensi
Brazilian Journal of Medical and Biological Research. Publicado em: 2003-05
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14. Neuroendocrine control of body fluid homeostasis
Angiotensin II and atrial natriuretic peptide (ANP) play important and opposite roles in the control of water and salt intake, with angiotensin II promoting the intake of both and ANP inhibiting the intake of both. Following blood volume expansion, baroreceptor input to the brainstem induces the release of ANP within the hypothalamus that releases oxytocin (
Brazilian Journal of Medical and Biological Research. Publicado em: 2003-02
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15. Effects of aerobic exercise training on heart rate variability during wakefulness and sleep and cardiorespiratory responses of young and middle-aged healthy men
The purpose of the present study was to evaluate the effects of aerobic physical training (APT) on heart rate variability (HRV) and cardiorespiratory responses at peak condition and ventilatory anaerobic threshold. Ten young (Y: median = 21 years) and seven middle-aged (MA = 53 years) healthy sedentary men were studied. Dynamic exercise tests were performed
Brazilian Journal of Medical and Biological Research. Publicado em: 2002-06
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16. Estudo do controle autonomico da frequencia cardiaca em ciclistas e sedentarios
The main purpose of this work was to study the heart rate (HR) control in subjects with different aerobic capacities, during the following situations: resting, Valsalva Maneuver (VM), Respiratory 8inus Arrhythmia (R8A) and Head-up Tilt (HUT). Participated of this cross-sectional study a group of sedentary subjects (8 group), that didn t practice any regular
Publicado em: 2001
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17. Effects of exercise training on autonomic and myocardial dysfunction in streptozotocin-diabetic rats
Several investigators have demonstrated that diabetes is associated with autonomic and myocardial dysfunction. Exercise training is an efficient non-pharmacological treatment for cardiac and metabolic diseases. The aim of the present study was to investigate the effects of exercise training on hemodynamic and autonomic diabetic dysfunction. After 1 week of d
Brazilian Journal of Medical and Biological Research. Publicado em: 2000-06
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18. Heart rate and haemodynamics after autonomic blockade in infants and children.
In order to assess the role of the autonomic system in the age differences in heart rate, propranolol 0.2 mg./kg. and atropine 30 micrograms/kg. were given to 103 infants and children during the course of heart catheterization. Mean control minute heart rate varied from 118 at age 1 year to 81 at age 16 years. Heart rate after drugs was termed intrinsic hear
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19. Relation between QT interval and heart rate. New design of physiologically adaptive cardiac pacemaker.
The relation between QT interval and heart rate has been studied in a group of patients undergoing physiological exercise, in a group undergoing atrial pacing without exercise, and in a group with complete heart block undergoing exercise at a fixed ventricular rate controlled by cardiac pacing. The expected shortening in QT interval during physiological exer
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20. An intrinsic adrenergic system in mammalian heart.
We have identified a previously undescribed intrinsic cardiac adrenergic (ICA) cell type in rodent and human heart. Northern and Western blot analyses demonstrated that ICA cell isolates contain mRNA and protein of enzymes involved in catecholamine biosynthesis. Radioenzymatic catecholamine assays also revealed that the catecholamine profile of adult rat ICA
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21. Failure of dopexamine to maintain haemodynamic improvement in patients with chronic heart failure.
Ten patients with chronic heart failure were given a continuous infusion of dopexamine after an initial stage of dose titration. On the dose selected the cardiac index initially rose by 56%, as a result of an increase in both heart rate and stroke volume index. Systemic vascular resistance fell by 34% and the mean arterial pressure did not change. Within 18
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22. Autonomic blockade by propranolol and atropine to study intrinsic myocardial function in man
Blockade of cardiac autonomic nervous activity by an intravenous injection of 0.2 mg/kg propranolol and 0.04 mg/kg atropine was used with cardiac catheterization to study intrinsic cardiac function in 47 patients with normal hearts and known graded myocardial disease. After blockade, significant hemodynamic abnormalities became apparent at rest in the majori
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23. Baroreflex sensitivity in hypertension during beta-adrenergic blockade.
Baroreceptor function was measured in 18 patients with essential hypertension by plotting the change in pulse interval against a phenylephrine-induced transient rise in systolic blood pressure. The influence of propranolol (160 mg daily for at least 4 weeks) on this function and on heart rate after maximal exercise was studied and correlated with the plasma
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24. Stereoselective renal clearance of pindolol in humans.
In this study, pindolol, a beta-adrenoceptor blocking agent marketed as a racemic mixture, was used as a model compound to investigate stereoselective renal clearance of organic cations in human beings. Six normal subjects received an oral dose of 20 mg racemic pindolol. Heart rate and blood pressure were measured throughout the study. A stereospecific high