|
|
|
| Registros recuperados: 10 | |
|
| |
|
|
| Farah,V.M.A.; Moreira,E.D.; Ushizima,M.; Cestari,I.A.; Irigoyen,M.C.; Krieger,E.M.. |
| To assess the role of angiotensin II in the sensitivity of the baroreflex control of heart rate (HR) in normotensive rats (N = 6) and chronically hypertensive rats (1K1C, 2 months, N = 7), reflex changes of HR were evaluated before and after (15 min) the administration of a selective angiotensin II receptor antagonist (losartan, 10 mg/kg, iv). Baseline values of mean arterial pressure (MAP) were higher in hypertensive rats (195 ± 6 mmHg) than in normotensive rats (110 ± 2 mmHg). Losartan administration promoted a decrease in MAP only in hypertensive rats (16%), with no changes in HR. During the control period, the sensitivity of the bradycardic and tachycardic responses to acute MAP changes were depressed in hypertensive rats (~70% and ~65%, respectively)... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Baroreflex sensitivity; Losartan; Angiotensin II; Renal hypertension. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001200014 |
| |
|
|
| Lopes,H.F.; Silva,H.B.; Consolim-Colombo,F.M.; Barreto Filho,J.A.S.; Riccio,G.M.G.; Giorgi,D.M.A.; Krieger,E.M.. |
| Although a slightly elevated office blood pressure (BP) has been reported in several studies, little is known about the prolonged resting blood pressure, heart rate (HR) and baroreflex sensitivity (BRS) of prehypertensive subjects with a family history of hypertension. Office blood pressure, prolonged resting (1 h) BP and HR were measured in 25 young normotensives with a positive family history of hypertension (FH+) and 25 young normotensives with a negative family history of hypertension (FH-), matched for age, sex, and body mass index. After BP and HR measurements, blood samples were collected for the determination of norepinephrine, plasma renin activity and aldosterone levels, and baroreflex sensitivity was then tested. Casual BP, prolonged resting BP... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heart rate; Blood pressure; Baroreflex sensitivity; Family history of hypertension. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000100007 |
| |
|
| |
|
|
| 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 |
| |
|
|
| Silva,G.J.J.; Ushizima,M.R.; Lessa,P.S.; Cardoso,L.; Drager,L.F.; Atala,M.M.; Consolim-Colombo,F.M.; Lopes,H.F.; Cestari,I.A.; Krieger,J.E.; Krieger,E.M.. |
| The autonomic nervous system plays an important role in physiological and pathological conditions, and has been extensively evaluated by parametric and non-parametric spectral analysis. To compare the results obtained with fast Fourier transform (FFT) and the autoregressive (AR) method, we performed a comprehensive comparative study using data from humans and rats during pharmacological blockade (in rats), a postural test (in humans), and in the hypertensive state (in both humans and rats). Although postural hypotension in humans induced an increase in normalized low-frequency (LFnu) of systolic blood pressure, the increase in the ratio was detected only by AR. In rats, AR and FFT analysis did not agree for LFnu and high frequency (HFnu) under basal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fast Fourier transform; Autoregressive model; Hypertension; SHR; Pharmacological blockade; Tilt test. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000400012 |
| |
|
|
| Fernandes,T.L.; Piratello,A.C.; Farah,V.; Fiorino,P.; Moreira,E.D.; Irigoyen,M.C.; Krieger,E.M.. |
| We determined the sympathetic and parasympathetic control of heart rate (HR) and the sensitivity of the cardiopulmonary receptors after selective carotid and aortic denervation. We also investigated the participation of the autonomic nervous system in the Bezold-Jarish reflex after selective removal of aortic and carotid baroreceptors. Male Wistar rats (220-270 g) were divided into three groups: control (CG, N = 8), aortic denervation (AG, N = 5) and carotid denervation (CAG, N = 9). AG animals presented increased arterial pressure (12%) and HR (11%) compared with CG, while CAG animals presented a reduction in arterial pressure (16%) and unchanged HR compared with CG. The sequential blockade of autonomic effects by atropine and propranolol indicated a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carotid denervation; Aortic denervation; Bezold-Jarish reflex. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010000700011 |
| |
|
| |
|
|
| Lopes,H.F.; Consolim-Colombo,F.M.; Barreto-Filho,J.A.S.; Riccio,G.M.G.; Negrão,C.E.; Krieger,E.M.. |
| Malignant hypertension seems to be the consequence of very high blood pressure. Furthermore, an increase in sympathetic and renin-angiotensin system activity is considered to be the main mechanisms producing malignant hypertension. In the present study, 10 offspring of malignant hypertensive (OMH) parents (age 28 ± 5 years, 7 males, 3 females, 2 white and 8 non-white) and 10 offspring of normotensive (ONT) parents (age 28 ± 6 years, 2 males, 8 females, 3 white and 7 non-white) were evaluated. The OMH group had significantly higher (P < 0.05) casual blood pressure (125 ± 10/81 ± 5 mmHg) compared with ONT (99 ± 13/67 ± 5 mmHg). The increase in blood pressure was greater in OMH (Δ SBP = 17 ± 2 vs Δ SBP = 9 ± 1 mmHg in ONT) during cold pressor testing, but... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Malignant hypertension; Offspring of malignant hypertensive parents; Sympathetic activity; Microneurography. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008001000003 |
| |
|
| |
| Registros recuperados: 10 | |
|
|
|
