SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

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)...

Blood flow measurements in rats using four color microspheres during blockade of different vasopressor systems

Palavras-chave: Baroreflex sensitivity; Losartan; Angiotensin II; Renal hypertension.

Ano: 2000

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001200014

De Angelis,K.; Gama,V.M.; Farah,V.A.M.; Irigoyen,M.C..

The use of colored microspheres to adequately evaluate blood flow changes under different circumstances in the same rat has been validated with a maximum of three different colors due to methodological limitations. The aim of the present study was to validate the use of four different colors measuring four repeated blood flow changes in the same rat to assess the role of vasopressor systems in controlling arterial pressure (AP). Red (150,000), white (200,000), yellow (150,000), and blue (200,000) colored microspheres were infused into the left ventricle of 6 male Wistar rats 1) at rest and 2) after vasopressin (aAVP, 10 µg/kg, iv), 3) renin-angiotensin (losartan, 10 mg/kg, iv), and 4) sympathetic system blockade (hexamethonium, 20 mg/kg, iv) to determine...

Cardiovascular control in experimental diabetes

Palavras-chave: Colored microspheres; Arterial pressure; Sympathetic system; Renin-angiotensin; Vasopressin; Local blood flow measurement.

Ano: 2005

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000100018

De Angelis,K.; Schaan,B.D.; Maeda,C.Y.; Dall'Ago,P.; Wichi,R.B.; Irigoyen,M.C..

Several studies have reported impairment in cardiovascular function and control in diabetes. The studies cited in this review were carried out from a few days up to 3 months after streptozotocin administration and were concerned with the control of the circulation. We observed that early changes (5 days) in blood pressure control by different peripheral receptors were maintained for several months. Moreover, the impairment of reflex responses observed after baroreceptor and chemoreceptor stimulation was probably related to changes in the efferent limb of the reflex arc (sympathetic and parasympathetic), but changes also in the central nervous system could not be excluded. Changes in renal sympathetic nerve activity during volume expansion were blunted in...

Dynamic resistance training decreases sympathetic tone in hypertensive ovariectomized rats

Palavras-chave: Experimental diabetes; Arterial pressure; Autonomic control; Baroreflex; Chemoreflex; Cardiopulmonary reflex; Exercise training.

Ano: 2002

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000900010

Effect of carotid and aortic baroreceptors on cardiopulmonary reflex: the role of autonomic function

Shimojo,G.L.; Palma,R.K.; Brito,J.O.; Sanches,I.C.; Irigoyen,M.C.; De Angelis,K..

The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and resistance-trained hypertensive ovariectomized (RTHO). Resistance exercise training was performed on a vertical ladder (5 days/week, 8 weeks) at 40-60% maximal load. Direct arterial pressure was recorded. Vagal and sympathetic tones were measured by heart rate (HR) responses to methylatropine (3 mg/kg, iv) and propranolol (4 mg/kg, iv). Ovariectomy resulted in additional increases in blood pressure in hypertensive rats and was associated...

Tipo: Info:eu-repo/semantics/report

Palavras-chave: Resistance exercise training; Menopause; Hypertension; Sympathetic tone; Blood pressure.

Ano: 2015

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000600523

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...

Effect of exercise training and carvedilol treatment on cardiac function and structure in mice with sympathetic hyperactivity-induced heart failure

Palavras-chave: Carotid denervation; Aortic denervation; Bezold-Jarish reflex.

Ano: 2010

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010000700011

Medeiro,A.; Vanzelli,A.S.; Rosa,K.T.; Irigoyen,M.C.; Brum,P.C..

The present investigation was undertaken to study the effect of β-blockers and exercise training on cardiac structure and function, respectively, as well as overall functional capacity in a genetic model of sympathetic hyperactivity-induced heart failure in mice (α2A/α2CArKO). α2A/α2CArKO and their wild-type controls were studied for 2 months, from 3 to 5 months of age. Mice were randomly assigned to control (N = 45), carvedilol-treated (N = 29) or exercise-trained (N = 33) groups. Eight weeks of carvedilol treatment (38 mg/kg per day by gavage) or exercise training (swimming sessions of 60 min, 5 days/week) were performed. Exercise capacity was estimated using a graded treadmill protocol and HR was measured by tail cuff. Fractional shortening was...

Effect of trolox C on cardiac contracture induced by hydrogen peroxide

Palavras-chave: Heart failure; Exercise training; Carvedilol treatment; Ventricular function; Cardiac remodeling; Α2A/α2CArKO mice.

Ano: 2008

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000900012

Belló-Klein,A.; Oliveira,A.R.; Miranda,M.F.S.; Irigoyen,M.C.; Homem-de-Bittencourt Jr.,P.I.; Llesuy,S.; Belló,A.A..

Hydrogen peroxide (H2O2) perfused into the aorta of the isolated rat heart induces a positive inotropic effect, with cardiac arrhythmia such as extrasystolic potentiation or cardiac contractures, depending on the dose. The last effect is similar to the "stone heart" observed in reperfusion injury and may be ascribed to lipoperoxidation (LPO) of the membrane lipids, to protein damage, to reduction of the ATP level, to enzymatic alterations and to cardioactive compounds liberated by LPO. These effects may result in calcium overload of the cardiac fibers and contracture ("stone heart"). Hearts from male Wistar rats (300-350 g) were perfused at 31oC with Tyrode, 0.2 mM trolox C, 256 mM H2O2 or trolox C + H2O2. Cardiac contractures (baseline elevation of the...

Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

Palavras-chave: Trolox C; "stone heart"; Free radicals; Hydrogen peroxide.

Ano: 1997

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001100013

Franco,O.S.; Paulitsch,F.S.; Pereira,A.P.C.; Teixeira,A.O.; Martins,C.N.; Silva,A.M.V.; Plentz,R.D.M.; Irigoyen,M.C.; Signori,L.U..

Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist)...

Effects of exercise training on autonomic and myocardial dysfunction in streptozotocin-diabetic rats

Palavras-chave: Electric stimulation therapy; Vascular endothelium; Alpha-1 adrenergic receptors; Mechanical pain.

Ano: 2014

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2014000500411

De Angelis,K.L.D.; Oliveira,A.R.; Dall'Ago,P.; Peixoto,L.R.A.; Gadonski,G.; Lacchini,S.; Fernandes,T.G.; Irigoyen,M.C..

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 diabetes induction (streptozotocin, 50 mg/kg, iv), male Wistar rats (222 ± 5 g, N = 18) were submitted to exercise training for 10 weeks on a treadmill. Arterial pressure signals were obtained and processed with a data acquisition system. Autonomic function and intrinsic heart rate were studied by injecting methylatropine and propranolol. Left ventricular function was assessed in hearts perfused in vitro...

Exercise training prevents increased intraocular pressure and sympathetic vascular modulation in an experimental model of metabolic syndrome

Palavras-chave: Experimental diabetes; Exercise training; Arterial pressure; Autonomic control; Myocardial contractility.

Ano: 2000

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000600004

Castro,E.F.S.; Mostarda,C.T.; Rodrigues,B.; Moraes-Silva,I.C.; Feriani,D.J.; De Angelis,K.; Irigoyen,M.C..

The present study aimed to study the effects of exercise training (ET) performed by rats on a 10-week high-fructose diet on metabolic, hemodynamic, and autonomic changes, as well as intraocular pressure (IOP). Male Wistar rats receiving fructose overload in drinking water (100 g/L) were concomitantly trained on a treadmill for 10 weeks (FT group) or kept sedentary (F group), and a control group (C) was kept in normal laboratory conditions. The metabolic evaluation comprised the Lee index, glycemia, and insulin tolerance test (KITT). Arterial pressure (AP) was measured directly, and systolic AP variability was performed to determine peripheral autonomic modulation. ET attenuated impaired metabolic parameters, AP, IOP, and ocular perfusion pressure (OPP)...

Familial history of hypertension-induced impairment on heart rate variability was not observed in strength-trained subjects

Palavras-chave: Fructose; Exercise training; Intraocular pressure; Autonomic modulation.

Ano: 2015

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000400332

Santa-Rosa,F.A.; Shimojo,G.L.; Sartori,M.; Rocha,A.C.; Francica,J.V.; Paiva,J.; Irigoyen,M.C.; De Angelis,K..

Family history of hypertension is an important predictive factor for hypertension and is associated with hemodynamic and autonomic abnormalities. Previous studies reported that strength training might reduce arterial blood pressure (AP), as well as improve heart rate variability (HRV). However, the benefits of strength training in the offspring of hypertensive parents have not been fully evaluated. Here, we analyzed the impact of strength training on hemodynamics and autonomic parameters in offspring of hypertensive subjects. We performed a cross-sectional study with sedentary or physically active offspring of normotensives (S-ON and A-ON) or hypertensives (S-OH and A-OH). We recorded RR interval for analysis of HRV. AP was similar between groups....

Hemodialysis improves endothelial venous function in end-stage renal disease

Palavras-chave: Family history; Arterial blood pressure; Cardiac autonomic modulation; Sympathetic modulation; Strength training.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2018001200605

Silva,A.M.V.; Signori,L.U.; Plentz,R.D.M.; Moreno Jr.,H.; Barros,E.; Belló-Klein,A.; Schaan,B.D.; Irigoyen,M.C..

The objective of the present study was to determine the acute effect of hemodialysis on endothelial venous function and oxidative stress. We studied 9 patients with end-stage renal disease (ESRD), 36.8 ± 3.0 years old, arterial pressure 133.8 ± 6.8/80.0 ± 5.0 mmHg, time on dialysis 55.0 ± 16.6 months, immediately before and after a hemodialysis session, and 10 healthy controls matched for age and gender. Endothelial function was assessed by the dorsal hand vein technique using graded local infusion of acetylcholine (endothelium-dependent venodilation, EDV) and sodium nitroprusside (endothelium-independent venodilation). Oxidative stress was evaluated by measuring protein oxidative damage (carbonyls) and antioxidant defense (total radical trapping...

Oxidative stress in the latissimus dorsi muscle of diabetic rats

Palavras-chave: End-stage renal disease; Hemodialysis; Oxidative stress; Vascular endothelium.

Ano: 2008

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000600008

De Angelis,K.L.D.; Cestari,I.A.; Barp,J.; Dall'Ago,P.; Fernandes,T.G.; Homem de Bittencourt,P.I.; Belló-Klein,A.; Belló,A.A.; Llesuy,S.; Irigoyen,M.C..

The purpose of the present study was to investigate the effects of experimental diabetes on the oxidant and antioxidant status of latissimus dorsi (LD) muscles of male Wistar rats (220 ± 5 g, N = 11). Short-term (5 days) diabetes was induced by a single injection of streptozotocin (STZ, 50 mg/kg, iv; glycemia >300 mg/dl). LD muscle of STZ-diabetic rats presented higher levels of thiobarbituric acid reactive substances (TBARS) and chemiluminescence (0.36 ± 0.02 nmol/mg protein and 14706 ± 1581 cps/mg protein) than LD muscle of normal rats (0.23 ± 0.04 nmol/mg protein and 7389 ± 1355 cps/mg protein). Diabetes induced a 92% increase in catalase and a 27% increase in glutathione S-transferase activities in LD muscle. Glutathione peroxidase activity was...

Parasympathetic dysfunction is associated with insulin resistance in fructose-fed female rats

Palavras-chave: Streptozotocin-diabetes; Latissimus dorsi muscle; Oxidative stress; Catalase; Glutathione.

Ano: 2000

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001100016

Brito,J.O.; Ponciano,K.; Figueroa,D.; Bernardes,N.; Sanches,Í.C.; Irigoyen,M.C.; De Angelis,K..

The objective of the present study was to identify metabolic, cardiovascular and autonomic changes induced by fructose overload administered in the drinking water of rats for 8 weeks. Female Wistar rats (200-220 g) were divided into 2 groups: control (N = 8) and fructose-fed rats (N = 5; 100 mg/L fructose in drinking water for 8 weeks). The autonomic control of heart rate was evaluated by pharmacological blockade using atropine (3 mg/kg) and propranolol (4 mg/kg). The animals were submitted to an intravenous insulin tolerance test (ITT) and to blood glucose measurement. The fructose overload induced a significant increase in body weight (~10%) and in fasting glycemia (~28%). The rate constant of glucose disappearance (KITT) during ITT was lower in...

Pleiotropic effects of simvastatin in physically trained ovariectomized rats

Palavras-chave: Female rats; Fructose; Blood pressure; Insulin resistance; Parasympathetic nervous system.

Ano: 2008

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000900010

Bernardes,N.; Brito,J.O.; Fernandes,T.G.; Llesuy,S.F.; Irigoyen,M.C.; Belló-Klein,A.; De Angelis,K..

This study tested the hypothesis that simvastatin treatment can improve cardiovascular and autonomic functions and membrane lipoperoxidation, with an increased effect when applied to physically trained ovariectomized rats. Ovariectomized rats were divided into sedentary, sedentary+simvastatin and trained+simvastatin groups (n = 8 each). Exercise training was performed on a treadmill for 8 weeks and simvastatin (5 mg/kg) was administered in the last 2 weeks. Blood pressure (BP) was recorded in conscious animals. Baroreflex sensitivity was evaluated by the tachycardic and bradycardic responses to BP changes. Cardiac vagal and sympathetic effects were determined using methylatropine and propranolol. Oxidative stress was evaluated based on heart and liver...

Reduced cortical renal GLUT1 expression induced by angiotensin-converting enzyme inhibition in diabetic spontaneously hypertensive rats

Palavras-chave: Menopause; Exercise training; Simvastatin; Autonomic function; Oxidative stress.

Ano: 2013

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000500447

Souza,M.S.; Machado,U.F.; Okamoto,M.; Bertoluci,M.C.; Ponpermeyer,C.; Leguisamo,N.; Azambuja,F.; Irigoyen,M.C.; Schaan,B.D..

Diabetes in spontaneously hypertensive rats is associated with cortical renal GLUT1 and GLUT2 overexpression. Our objective was to evaluate the effect of the angiotensin-converting enzyme blockade on cortical renal GLUT1 and GLUT2 expression, urinary albumin and urinary TGF-β1. Streptozotocin, 50 mg/kg, or citrate buffer (N = 16) was administered as a single injection into the tail vein in adult spontaneously hypertensive rats (~260 g). Thirty days later, these diabetic spontaneously hypertensive rats received ramipril by gavage: 0.01 mg·kg-1·day-1 (D0.01, N = 14), 1 mg·kg-1·day-1 (D1, N = 9) or water (D, N = 11) for 15 days. Albumin and TGF-β1 (24-h urine), direct arterial pressure, renal tissue angiotensin-converting enzyme activity (fluorometric assay),...

Reflex control of arterial pressure and heart rate in short-term streptozotocin diabetic rats

Palavras-chave: Angiotensin-converting enzyme inhibition; Diabetes mellitus; Diabetic nephropathy; Glucose transporter proteins; Hypertension; Streptozotocin.

Ano: 2008

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008001100004

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...

Relationship between cardiovascular dysfunction and hyperglycemia in streptozotocin-induced diabetes in rats

Palavras-chave: Baroreflex; Baroreceptors; Streptozotocin; Vagus nerve.

Ano: 2002

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000700013

Schaan,B.D.; Dall'Ago,P.; Maeda,C.Y.; Ferlin,E.; Fernandes,T.G.; Schmid,H.; Irigoyen,M.C..

Streptozotocin (STZ)-induced diabetes in rats is characterized by cardiovascular dysfunction beginning 5 days after STZ injection, which may reflect functional or structural autonomic nervous system damage. We investigated cardiovascular and autonomic function, in rats weighing 166 ± 4 g, 5-7, 14, 30, 45, and 90 days after STZ injection (N = 24, 33, 27, 14, and 13, respectively). Arterial pressure (AP), mean AP (MAP) variability (standard deviation of the mean of MAP, SDMMAP), heart rate (HR), HR variability (standard deviation of the normal pulse intervals, SDNN), and root mean square of successive difference of pulse intervals (RMSSD) were measured. STZ induced increased glycemia in diabetic rats vs control rats. Diabetes reduced resting HR from 363 ± 12...

Time course of changes in heart rate and blood pressure variability in streptozotocin-induced diabetic rats treated with insulin

Palavras-chave: Diabetes; Streptozotocin; Heart rate variability; Rats; Autonomic nervous system; Arterial pressure variability.

Ano: 2004

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004001200016

Schaan,B.D.; Maeda,C.Y.; Timm,H.B.; Medeiros,S.; Moraes,R.S.; Ferlin,E.; Fernandes,T.G.; Ribeiro,J.P.; Schmid,H.; Irigoyen,M.C..

Autonomic neuropathy is a frequent complication of diabetes associated with higher morbidity and mortality in symptomatic patients, possibly because it affects autonomic regulation of the sinus node, reducing heart rate (HR) variability which predisposes to fatal arrhythmias. We evaluated the time course of arterial pressure and HR and indirectly of autonomic function (by evaluation of mean arterial pressure (MAP) variability) in rats (164.5 ± 1.7 g) 7, 14, 30 and 120 days after streptozotocin (STZ) injection, treated with insulin, using measurements of arterial pressure, HR and MAP variability. HR variability was evaluated by the standard deviation of RR intervals (SDNN) and root mean square of successive difference of RR intervals (RMSSD). MAP...

Tonic and reflex cardiovascular autonomic control in trained-female rats

Palavras-chave: Diabetes mellitus; Streptozotocin; Insulin; Autonomic nervous system.

Ano: 1997

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000900006

Sanches,I.C.; Sartori,M.; Jorge,L.; Irigoyen,M.C.; De Angelis,K..

The effects of exercise training on cardiovascular and autonomic functions were investigated in female rats. After an aerobic exercise training period (treadmill: 5 days/week for 8 weeks), conscious female Wistar (2 to 3 months) sedentary (S, N = 7) or trained rats (T, N = 7) were cannulated for direct arterial pressure (AP) recording in the non-ovulatory phases. Vagal (VT) and sympathetic tonus (ST) were evaluated by vagal (atropine) and sympathetic (propranolol) blockade. Baroreflex sensitivity was evaluated by the heart rate responses induced by AP changes. Cardiopulmonary reflex was measured by the bradycardic and hypotensive responses to serotonin. Resting bradycardia was observed in T (332 ± 7 bpm) compared with S animals (357 ± 10 bpm), whereas AP...