Consulta: creatorFacets:"Salgado,H.C."
Registros recuperados: 10
Data/hora: 16/06/2024 04:22:59

Hemodynamic responses to acute aortic coarctation in conscious sinoaortic denervated rats
Provedor de dados: 56
Autores: Fazan Jr.,R.; Machado,B.H.; Salgado,H.C.
The hemodynamic responses to acute (45 min) partial aortic constriction were studied in conscious intact (N = 7) or sinoaortic denervated (SAD) adult male Wistar rats (280-350 g, N = 7) implanted with carotid and femoral arterial catheters, a pneumatic cuff around the abdominal aorta and a pulsed Doppler flow probe to measure changes in aortic resistance. In addition, the hypertensive response and the reflex bradycardia elicited by total (N = 8) vs partial (N = 7) aortic constriction (monitored by maintenance of the pressure distal to the cuff at 50 mmHg) were compared in two other groups of intact rats. Intact rats presented a smaller hypertensive response (26 to 40% above basal level) to partial aortic constriction than SAD rats (38 to 58%). The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hypertension; Aortic coarctation; Doppler flowmetry; Aortic resistance; Reflex bradycardia; Sinoaortic denervation.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001000018

Acute effect of amiodarone on cardiovascular reflexes of normotensive and renal hypertensive rats
Provedor de dados: 56
Autores: 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

Ovariectomy does not affect the cardiac sympathovagal balance of female SHR but estradiol does
Provedor de dados: 56
Autores: Dias,D.P.M.; Oliveira,M.; Salgado,H.C.; Fazan Jr.,R.
The low incidence of cardiovascular diseases, including hypertension, in premenopausal women has led to the conclusion that ovarian hormones may have a protective effect on the cardiovascular system. We evaluated the effects of ovariectomy and/or estradiol on sympathovagal balance and heart rate variability (HRV) in female spontaneously hypertensive rats (SHR) with tachycardia and compared them to Wistar rats (12 weeks old; N = 8-12). Ovariectomy (OVX) and/or estradiol (10 µg/kg) did not affect basal arterial pressure in either rat strain, but estradiol increased basal heart rate (HR) in OVX SHR (454 ± 18 vs 377 ± 9 bpm). HR changes elicited by methylatropine and propranolol were used to evaluate the sympathovagal balance. Ovariectomy did not affect the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Estrogen; SHR; Heart rate variability; Hypertension; Sympathovagal balance.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010001000008

Does acute hyperglycemia alter rat aortic depressor nerve function?
Provedor de dados: 56
Autores: Huber,D.A.; Carmo,J.M. do; Castania,J.A.; Fazan Jr,R.; Salgado,H.C.
Because it is not known where in the reflex arch, i.e., afference, central nervous system or efferences, hyperglycemia affects baroreflex function, the present study examined the effect of short-term (30 min) hyperglycemia on aortic depressor nerve function measured by a mean arterial pressure vs aortic depressor nerve activity curve, fitted by sigmoidal regression, or by cross-spectral analysis between mean arterial pressure and aortic depressor nerve activity. Anesthetized male Wistar rats received an intravenous bolus (0.25 mL) injection, followed by 30 min of infusion (1 mL/h) of 30% glucose (N = 14). Control groups received a bolus injection and infusion of 0.9% saline (N = 14), or 30% mannitol (N = 14). Glucose significantly increased both blood...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pressoreceptors; Hyperglycemia; Arterial pressure; Spectral analysis.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001100017

Reflex control of arterial pressure and heart rate in short-term streptozotocin diabetic rats
Provedor de dados: 56
Autores: Dall'Ago,P.; Silva,V.O.K.; De Angelis,K.L.D.; Irigoyen,M.C.; Fazan Jr.,R.; Salgado,H.C.
Impaired baroreflex sensitivity in diabetes is well described and has been attributed to autonomic diabetic neuropathy. In the present study conducted on acute (10-20 days) streptozotocin (STZ)-induced diabetic rats we examined: 1) cardiac baroreflex sensitivity, assessed by the slope of the linear regression between phenylephrine- or sodium nitroprusside-induced changes in arterial pressure and reflex changes in heart rate (HR) in conscious rats; 2) aortic baroreceptor function by means of the relationship between systolic arterial pressure and aortic depressor nerve (ADN) activity, in anesthetized rats, and 3) bradycardia produced by electrical stimulation of the vagus nerve or by the iv injection of methacholine in anesthetized animals. Reflex...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Baroreflex; Baroreceptors; Streptozotocin; Vagus nerve.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000700013

Chronic converting enzyme inhibition normalizes QT interval in aging rats
Provedor de dados: 56
Autores: Silva,V.J. Dias da; Ferreira Neto,E.; Salgado,H.C.; Fazan Júnior,R.
The aim of the present study was to investigate the effects of converting enzyme inhibition by captopril on ECG parameters in aged rats. Four-month-old male rats received captopril dissolved in tap water (0.5 mg/l) or tap water for 2 or 20 months. At the end of treatment, under anesthesia, RR and PR interval, P wave and QRS duration, QT and corrected QT interval were measured in all animals. On the following day, chronic ECG (lead II) recordings were performed to quantify supraventricular (SVPB) or ventricular premature beats (VPB). After sacrifice, the hearts were removed and weighed. RR interval was similar in young and untreated aged rats, but significantly larger in aged rats treated with captopril. P wave and QRS length did not differ among groups. PR...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aging; Electrocardiogram; Captopril; Rats.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000900003

Acute and chronic electrical activation of baroreceptor afferents in awake and anesthetized subjects
Provedor de dados: 56
Autores: Durand,M.T.; Fazan Jr.,R.; Salgado,M.C.O.; Salgado,H.C.
Electrical stimulation of baroreceptor afferents was used in the 1960's in several species, including human beings, for the treatment of refractory hypertension. This approach bypasses the site of baroreceptor mechanosensory transduction. Chronic electrical stimulation of arterial baroreceptors, particularly of the carotid sinus nerve (Hering's nerve), was proposed as an ultimate effort to treat refractory hypertension and angina pectoris due to the limited nature of pharmacological therapy available at that time. Nevertheless, this approach was abandoned in the early 1970's due to technical limitations of implantable devices and to the development of better-tolerated antihypertensive medications. More recently, our laboratory developed the technique of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carotid sinus nerve; Aortic depressor nerve; Hemodynamics; Baroreceptor stimulation; Refractory hypertension.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000100009

Morphometric analysis of the phrenic nerve in male and female Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR)
Provedor de dados: 56
Autores: Rodrigues,A.R.; Ferreira,R.S.; Salgado,H.C.; Fazan,V.P.S.
Ventilatory differences between rat strains and genders have been described but the morphology of the phrenic nerve has not been investigated in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. A descriptive and morphometric study of the phrenic nerves of male (N = 8) and female (N = 9) SHR, and male (N = 5) and female (N = 6) WKY is presented. After arterial pressure and heart rate recordings, the phrenic nerves of 20-week-old animals were prepared for epoxy resin embedding and light microscopy. Morphometric analysis performed with the aid of computer software that took into consideration the fascicle area and diameter, as well as myelinated fiber profile and Schwann cell nucleus number per area. Phrenic nerves were generally...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Phrenic nerve; Sexual dimorphism; Morphometry; Spontaneously hypertensive rats; Wistar-Kyoto rats; Asymmetry.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000600012

Effect of different anesthetic agents on left ventricular systolic function assessed by echocardiography in hamsters
Provedor de dados: 56
Autores: Tanaka,D.M.; Romano,M.M.D.; Carvalho,E.E.V.; Oliveira,L.F.L.; Souza,H.C.D.; Maciel,B.C.; Salgado,H.C.; Fazan-Júnior,R.; Simões,M.V.
Determination of left ventricular ejection fraction (LVEF) using in vivo imaging is the cardiac functional parameter most frequently employed in preclinical research. However, there is considerable conflict regarding the effects of anesthetic agents on LVEF. This study aimed at assessing the effects of various anesthetic agents on LVEF in hamsters using transthoracic echocardiography. Twelve female hamsters were submitted to echocardiography imaging separated by 1-week intervals under the following conditions: 1) conscious animals, 2) animals anesthetized with isoflurane (inhaled ISO, 3 L/min), 3) animals anesthetized with thiopental (TP, 50 mg/kg, intraperitoneal), and 4) animals anesthetized with 100 mg/kg ketamine plus 10 mg/kg xylazine injected...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Echocardiography; Anesthetics; Systolic function; Hamsters.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2016001000602

Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats
Provedor de dados: 56
Autores: 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