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| Registros recuperados: 14 | |
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| Oliveira,P.F.; Dias da Silva,V.J.; Salgado,M.C.O.; Fazan Jr.,R.; Aguiar,C.A.; Salgado,H.C.. |
| The aim of the present study was to evaluate the effect of amiodarone on mean arterial pressure (MAP), heart rate (HR), baroreflex, Bezold-Jarisch, and peripheral chemoreflex in normotensive and chronic one-kidney, one-clip (1K1C) hypertensive rats (N = 9 to 11 rats in each group). Amiodarone (50 mg/kg, iv) elicited hypotension and bradycardia in normotensive (-10 ± 1 mmHg, -57 ± 6 bpm) and hypertensive rats (-37 ± 7 mmHg, -39 ± 19 bpm). The baroreflex index (deltaHR/deltaMAP) was significantly attenuated by amiodarone in both normotensive (-0.61 ± 0.12 vs -1.47 ± 0.14 bpm/mmHg for reflex bradycardia and -1.15 ± 0.19 vs -2.63 ± 0.26 bpm/mmHg for reflex tachycardia) and hypertensive rats (-0.26 ± 0.05 vs -0.72 ± 0.16 bpm/mmHg for reflex bradycardia and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amiodarone; Baroreflex; Bezold-Jarisch reflex; Chemoreflex; Autonomic nervous system; 1K1C hypertension. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000600020 |
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| Cardoso,L.M.; Pedrosa,M.L.; Silva,M.E.; Moraes,M.F.D.; Colombari,E.; Chianca-Jr.,D.A.. |
| Our hypothesis is that iron accumulated in tissue, rather than in serum, may compromise cardiovascular control. Male Fischer 344 rats weighing 180 to 220 g were divided into 2 groups. In the serum iron overload group (SIO, N = 12), 20 mg elemental iron was injected ip daily for 7 days. In the tissue iron overload group (TIO, N = 19), a smaller amount of elemental iron was injected (10 mg, daily) for 5 days followed by a resting period of 7 days. Reflex heart rate responses were elicited by iv injections of either phenylephrine (0.5 to 5.0 µg/kg) or sodium nitroprusside (1.0 to 10.0 µg/kg). Baroreflex curves were determined and fitted to sigmoidal equations and the baroreflex gain coefficient was evaluated. To evaluate the role of other than a direct effect... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Baroreflex; Iron overload; Heart rate; Blood pressure; Iron dextran; Deferoxamine. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000200008 |
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| Buto,M.S.S.; Catai,A.M.; Vassimon-Barroso,V.; Gois,M.O.; Porta,A.; Takahashi,A.C.M.. |
| Frailty is related to a decrease in the physiological reserves, which causes difficulties in maintaining homeostasis. An example of physiological mechanisms for cardiovascular homeostasis is the baroreflex. The aim of this study was to compare baroreflex among frail, prefrail, and nonfrail individuals, in supine and orthostatic positions. Community-dwelling older adults were evaluated and categorized into frail, prefrail, or nonfrail groups, according to frailty phenotype. The RR interval (RRi) and systolic blood pressure (SBP) series were recorded for 15 min in the supine and 15 min in the orthostatic positions. Mean and variance of RRi and SBP, and baroreflex evaluated by phase, gain (α), and coherence (K2) were determined. A two-way repeated measures... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Baroreflex; Autonomic nervous system; Aging; Frailty. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2019000400602 |
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| Farah,V.M.A.; Moreira,E.D.; Pires,M.D.; Irigoyen,M.C.C.; Krieger,E.M.. |
| Baroreflex sensitivity was studied in the same group of conscious rats using vasoactive drugs (phenylephrine and sodium nitroprusside) administered by three different approaches: 1) bolus injection, 2) steady-state (blood pressure (BP) changes produced in steps), 3) ramp infusion (30 s, brief infusion). The heart rate (HR) responses were evaluated by the mean index (mean ratio of all HR changes and mean arterial pressure (MAP) changes), by linear regression and by the logistic method (maximum gain of the sigmoid curve by a logistic function). The experiments were performed on three consecutive days. Basal MAP and resting HR were similar on all days of the study. Bradycardic responses evaluated by the mean index (-1.5 ± 0.2, -2.1 ± 0.2 and -1.6 ± 0.2... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Baroreflex; Baroreceptor; Bradycardia; Tachycardia. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000300018 |
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| The maintenance of arterial pressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-moment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterial pressure (baroreflex), blood volume or chemical composition (mechano- and chemosensitive cardiopulmonary reflexes), and changes in blood-gas composition (chemoreceptor reflex). The importance of the integration of these cardiovascular reflexes is well understood and it... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Arterial pressure; Bezold-Jarisch reflex; Baroreflex; Chemoreflex. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000400014 |
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| Durand,M.T.; Mota,A.L.; Barale,A.R.; Castania,J.A.; Fazan Jr.,R.; Salgado,H.C.. |
| 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) under thiopental anesthesia. 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... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrical stimulation; Arterial pressure; Aortic depressor nerve; Baroreflex; Spontaneously hypertensive rats; Vascular tone. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000500010 |
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| Registros recuperados: 14 | |
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