RESUMEN
Physical fitness is closely related to cardiovascular health. We examined the effects of estradiol, angiotensin-converting enzyme inhibitor, exercise training, and their combination on exercise capacity as well as skeletal muscle fiber type and capillarity in old female rats. Twelve-month-old female Wistar-Kyoto rats were allocated to six groups: control (C), treatment with 17 beta-estradiol (0.025 mg/kg/dose, i.p. twice a week) (Est), perindopril (2 mg/kg/day) (Per), exercise training on a treadmill (15 m/min, 10 grade incline, 60 min/day, 5 days/week) (Exe), and combinations of a drug and exercise training (Exe+Est and Exe+Per). Following 6-month interventions, the rats were submitted to a stepwise exercise test on a treadmill. Moreover, fiber type and capillarity in both the soleus and gastrocnemius muscles were examined. Exercise capacity, capillary density, and the percentage of type I fiber significantly increased in Exe, Exe+Est, and Exe+Per compared to C. There were no significant differences in exercise capacity, capillary density, and percentage of type I fiber among C, Est, and Per. The combination of exercise training and perindopril further increased capillary density in both the soleus and gastrocnemius muscles, and the percentage of type I fiber in the gastrocnemius muscle compared to exercise training alone. We found that in old female rats, chronic treatment with estradiol or perindopril affected neither untrained exercise capacity nor exercise capacity acquired as a result of exercise training. However, we found that perindopril promotes adaptive changes of skeletal muscle in response to exercise such as increases in capillary density and the percentage of type I fiber.
Asunto(s)
Envejecimiento/efectos de los fármacos , Envejecimiento/fisiología , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Estradiol/farmacología , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/fisiología , Condicionamiento Físico Animal/fisiología , Animales , Presión Sanguínea , Composición Corporal/efectos de los fármacos , Composición Corporal/fisiología , Femenino , Modelos Animales , Músculo Esquelético/irrigación sanguínea , Perindopril/farmacología , Esfuerzo Físico/efectos de los fármacos , Esfuerzo Físico/fisiología , Ratas , Ratas Endogámicas WKYRESUMEN
Favorable effects of exercise training on cardiovascular prognosis have been reported repeatedly in patients with diabetes mellitus type 2 (DM2). However, little is known about the cardiovascular rehabilitation effects in diabetic patients with coronary artery disease (CAD). This study has evaluated the benefits of combined aerobic-resistance training in two groups of patients--diabetics and non-diabetics--after percutaneous coronary intervention (PCI). Changes in exercise capacity parameters, resting cardiovascular and anthropometrical parameters were evaluated in 77 patients who completed 12-weeks of combined aerobic-resistance training: 32 patients with DM2 (DM) and 45 patients without DM2 (NDM). Significant improvements in exercise capacity (total peak workload [W(peak)], peak workload per kg of body weight [W(peak)/kg], total peak oxygen uptake [VO(2peak)], peak oxygen uptake per kg of body weight [VO(2peak)/kg]) were found in both DM and NDM (p < 0.01 and p < 0.001, respectively). The decrease in resting heart rate (HR(rest)), resting systolic (SBP(rest)) resting diastolic (DBP(rest)) blood pressures, body weight (BW) and BMI in the DM group was not statistically significant. However, there was a statistically significant decrease in SBP(rest), BW and BMI in the NDM group. In conclusion, this study demonstrated similar beneficial effects of combined cardiovascular training on exercise capacity in patients with or without type 2 diabetes mellitus. Our results suggest that the combined cardiac training is well tolerated and useful in secondary prevention in patients with DM2 and CAD.
Asunto(s)
Síndrome Coronario Agudo/fisiopatología , Síndrome Coronario Agudo/rehabilitación , Diabetes Mellitus Tipo 2/fisiopatología , Terapia por Ejercicio , Ejercicio Físico/fisiología , Terapia Combinada , Diabetes Mellitus Tipo 2/rehabilitación , Femenino , Humanos , Masculino , Persona de Mediana Edad , DescansoRESUMEN
We examined the effects of antihypertensive drugs, exercise training, and combinations thereof on insulin sensitivity (IS), and the association between this relation and sympathetic activity, muscle fiber composition, and capillary density in spontaneously hypertensive rats (SHR). Six-week-old male SHR were allocated to 7 groups: a control group (C), and groups treated with azelnidipine (Aze) (a calcium channel blocker), olmesartan (Olm) (an angiotensin II type 1 receptor blocker), exercise training (Exe), and combinations of drugs and exercise training (Aze+Exe, Olm+Exe, and Olm+Aze+Exe). At age 18 weeks, IS and sympathetic activity were evaluated by an euglycemic hyperinsulinemic glucose clamp technique and power spectral analysis of systolic blood pressure, respectively. After the experiments, capillary density and muscle fiber composition in soleus muscle were examined. Aze or Exe alone significantly increased IS associated with a significant reduction in sympathetic activity. Olm alone tended to increase IS with little change in sympathetic activity. Aze, Olm, or Exe significantly increased the capillary density and percentage of insulin-sensitive type I fiber. A combination of Aze and Exe or a combination of Olm and Exe tended to increase IS compared with each drug therapy alone. There were significant correlations between IS and sympathetic activity, capillary density, and the percentage of type I fiber in all the rats. We found that Aze improved IS more substantially compared with Olm in SHR. We also found that Aze, Olm, Exe, and combinations thereof improved IS, probably through the modulation of sympathetic activity or capillarity and muscle fiber type in skeletal muscles.
Asunto(s)
Antihipertensivos/farmacología , Ácido Azetidinocarboxílico/análogos & derivados , Dihidropiridinas/farmacología , Hipertensión/fisiopatología , Imidazoles/farmacología , Resistencia a la Insulina/fisiología , Condicionamiento Físico Animal/fisiología , Tetrazoles/farmacología , Animales , Antihipertensivos/uso terapéutico , Ácido Azetidinocarboxílico/farmacología , Ácido Azetidinocarboxílico/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Terapia Combinada , Dihidropiridinas/uso terapéutico , Modelos Animales de Enfermedad , Quimioterapia Combinada , Frecuencia Cardíaca/efectos de los fármacos , Hipertensión/terapia , Imidazoles/uso terapéutico , Insulina/fisiología , Masculino , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/patología , Ratas , Ratas Endogámicas SHR , Análisis de Regresión , Sistema Nervioso Simpático/efectos de los fármacos , Sistema Nervioso Simpático/fisiopatología , Tetrazoles/uso terapéuticoRESUMEN
OBJECTIVE: Physical fitness is closely related with cardiovascular health. We examined the effects of angiotensin-converting enzyme inhibitor, exercise training and their combination on exercise capacity as well as skeletal muscle fiber type and capillarity in spontaneously hypertensive rats (SHR). METHODS: Seven-week-old male SHR were allocated to four groups: sedentary control (C), treatment with perindopril (3 mg/kg per day) (Per), exercise training on a treadmill (EX), and their combination (Per + EX). Following 8-week interventions, rats were submitted to a stepwise exercise test on a treadmill. After experiments, fiber type and capillarity in soleus muscle were examined. RESULTS: Exercise capacity significantly increased in Per compared with in C. Combination of exercise training and perindopril further increased exercise capacity compared with perindopril alone, whereas there was no significant difference in exercise capacity between EX and Per + EX. Capillary density increased similarly in Per and EX compared with in C. Combination of exercise training and perindopril further increased capillary density compared with exercise training alone. The percentage of type I fiber increased only in Per + EX. CONCLUSIONS: We found that in growing SHR, chronic treatment with perindopril enhances untrained exercise capacity, while it does not affect acquired exercise capacity as a result of exercise training. We also found that perindopril promotes adaptive changes of skeletal muscle in response to exercise such as increases in capillary density and percentage of type I fiber.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Hipertensión/fisiopatología , Músculo Esquelético/fisiología , Perindopril/farmacología , Condicionamiento Físico Animal/fisiología , Animales , Prueba de Esfuerzo , Hipertensión/genética , Lactatos/farmacología , Masculino , Músculo Esquelético/efectos de los fármacos , Aptitud Física/fisiología , Ratas , Ratas Endogámicas SHRRESUMEN
In men, exercise training attenuates age-related reduction in baroreflex sensitivity, which is related to cardiovascular health. It is unknown, however, if this holds true for post-menopausal women. We examined the effects of exercise training on baroreceptor-heart rate (HR) reflex sensitivity in ovariectomized (OVX) and sham-operated (SO) Wistar-Kyoto rats. At the age of 8 weeks, OVX and SO rats were assigned to either sedentary or exercise-trained group. Exercise training was performed on a treadmill 5 days per week. At the age of 20 weeks, baroreflex sensitivity in response to increases in blood pressure (BRSinc) and decreases in blood pressure (BRSdec) were evaluated by injections of phenylephrine and sodium nitroprusside, respectively. Both BRSinc and BRSdec were significantly reduced in sedentary OVX rats compared with sedentary SO rats. Exercise training decreased resting HR and BRSdec, but had no effect on BRSinc in SO rats. In OVX rats, exercise training decreased resting HR but modified neither BRSdec nor BRSinc. We conclude that withdrawal of female sex hormones in normotensive female rats is associated with reduced baroreflex sensitivity in response to both increase and decrease in blood pressure and that exercise training fails to modulate the decline of BRSinc associated with withdrawal of female sex hormones. To maintain high level of BRSinc in post-menopausal women, hormone replacement therapy may be needed.
Asunto(s)
Barorreflejo/fisiología , Ovario/fisiología , Condicionamiento Físico Animal/fisiología , Envejecimiento/fisiología , Animales , Presión Sanguínea/efectos de los fármacos , Bradicardia/fisiopatología , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Menopausia/fisiología , Modelos Animales , Nitroprusiato/farmacología , Ovariectomía , Fenilefrina/farmacología , Ratas , Ratas Endogámicas WKY , Taquicardia/fisiopatologíaRESUMEN
The enantioselectivity of the self-assembled monolayer (SAM) of homocysteine formed on the (111)-oriented gold surface was investigated. We analyzed the redox behavior of 3,4-dihydroxyphenylalanine (DOPA), which is an electrochemically active chiral molecule, by means of cyclic voltammetry at a gold electrode modified with one enantiomeric form of homocysteine. It was demonstrated that the homocysteine SAM of one enantiomeric form blocked the redox reaction of only one enantiomer of DOPA, with cross inversion for the other enantiomer, in acidic solution.
Asunto(s)
Técnicas Biosensibles/métodos , Dihidroxifenilalanina/química , Dopaminérgicos/química , Oro/química , Homocistina/química , Electroquímica , Electrodos , Concentración de Iones de Hidrógeno , Oxidación-Reducción , Propiedades de SuperficieRESUMEN
The aim of this study was to investigate whether electrical stimulation of skeletal muscles could represent a rehabilitation alternative for patients with chronic heart failure (CHF). Thirty patients with CHF and NYHA class II-III were randomly assigned to a rehabilitation program using either electrical stimulation of skeletal muscles or bicycle training. Patients in the first group (n = 15) had 8 weeks of home-based low-frequency electrical stimulation (LFES) applied simultaneously to the quadriceps and calf muscles of both legs (1 h/day for 7 days/week); patients in the second group (n = 15) underwent 8 weeks of 40 minute aerobic exercise (3 times a week). After the 8-week period significant increases in several functional parameters were observed in both groups: maximal VO2 uptake (LFES group: from 17.5 +/- 4.4 mL/kg/min to 18.3 +/- 4.2 mL/kg/min, P < 0.05; bicycle group: from 18.1 +/- 3.9 mL/kg/min to 19.3 +/- 4.1 mL/kg/min, P < 0.01), maximal workload (LFES group: from 84.3 +/- 15.2 W to 95.9 +/- 9.8 W, P < 0.05; bicycle group: from 91.2 +/- 13.4 W to 112.9 +/- 10.8 W, P < 0.01), distance walked in 6 minutes (LFES group: from 398 +/- 105 m to 435 +/- 112 m, P < 0.05; bicycle group: from 425 +/- 118 m to 483 +/- 120 m, P < 0.03), and exercise duration (LFES group: from 488 +/- 45 seconds to 568 +/- 120 seconds, P < 0.05; bicycle group: from 510 +/- 90 seconds to 611 +/- 112 seconds, P < 0.03). These results demonstrate that an improvement of exercise capacities can be achieved either by classical exercise training or by home-based electrical stimulation. LFES should be considered as a valuable alternative to classical exercise training in patients with CHF.
Asunto(s)
Ciclismo/fisiología , Terapia por Estimulación Eléctrica/métodos , Terapia por Ejercicio/métodos , Insuficiencia Cardíaca/rehabilitación , Músculo Esquelético/fisiología , Presión Sanguínea , Enfermedad Crónica , Tolerancia al Ejercicio/fisiología , Femenino , Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Calidad de Vida , Volumen Sistólico/fisiologíaRESUMEN
1. Low-voltage electrical stimulation (LVES) in skeletal muscle at a level far below the threshold of muscle contraction has been reported to promote local angiogenesis. However, the mechanism underlying the promotion of local angiogenesis by LVES has not been fully elucidated. In the present study, we evaluated whether angiogenic factors, such as vascular endotherial growth factor (VEGF), hepatocyte growth factor (HGF) and fibroblast growth factor (FGF), as well as other disadvantageous factors, such as inflammation (interleukin (IL)-6) and hypoxia (hypoxia-inducible factor (HIF)-1alpha), contribute to the local angiogenesis produced by LVES. 2. We completely excised bilateral femoral arteries of male Sprague-Dawley rats. After the operation, electrodes were implanted onto the centre of the fascia of the bilateral tibialis anterior (TA) muscles, tunnelled subcutaneously and exteriorized at the level of the scapulae. The right TA muscles of rats were stimulated continuously at a stimulus frequency of 50 Hz, with a 0.1 V stimulus strength and no interval, for 5 days. The left TA muscles served as controls. 3. We found that both VEGF and HGF protein were significantly increased by LVES in stimulated muscles compared with control. The VEGF level of the LVES group was 89.10 +/- 17.19 ng/g, whereas that of the control group was 65.07 +/- 12.88 ng/g, as determined by ELISA (P < 0.05). The HGF level of the LVES and control groups was 8.52 +/- 1.96 and 5.80 +/- 2.14 ng/g, respectively (P < 0.05). In contrast, there was no difference in FGF, IL-6 and HIF-1alpha between the LVES and control groups. 4. These results suggest that LVES in a hindlimb ischaemia model of rats increases not only VEGF, but also HGF, production, which may be the main mechanism responsible for the angiogenesis produced by LVES.
Asunto(s)
Proteínas Angiogénicas/metabolismo , Factor de Crecimiento de Hepatocito/metabolismo , Isquemia/metabolismo , Músculo Esquelético/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Estimulación Eléctrica , Ensayo de Inmunoadsorción Enzimática , Miembro Posterior , Inmunohistoquímica , Masculino , Músculo Esquelético/irrigación sanguínea , Ratas , Ratas Sprague-Dawley , Regulación hacia ArribaRESUMEN
A single bout of dynamic exercise increases baroreflex sensitivity (BRS) in spontaneously hypertensive rats (SHR). We examined whether change in hemodynamics (increases in blood pressure and heart rate) associated with dynamic exercise contribute to the post-exercise modulation of BRS. SHR aged 12 weeks were chronically instrumented with a carotid artery catheter and jugular vein catheter. They were then allocated to three groups submitted to 40 min of 1) running on a treadmill at 12 m/min (Run), 2) concomitant infusion of isoproterenol and a relatively high dose of phenylephrine (Iso+Phe(high)), or 3) concomitant infusion of isoproterenol and a relatively low dose of phenylephrine (Iso+Phe(low)). Arterial pressure and heart rate were continuously recorded throughout the experiments. BRS estimated by heart rate responses to phenylephrine injection and systolic blood pressure-low frequency power amplitude (SBP-LFamp) evaluated by power spectral analysis of SBP, a marker of sympathetic activity, were examined before and after running (Run group), or administration of drugs (Iso+Phe(high) or Iso+Phe(low) groups). BRS increased significantly from 1.4 to 1.9 bpm/mmHg after running, but not after administration of Iso+Phe(high) or Iso+Phe(low). Blood pressure and SBP-LFamp significantly decreased in each of the Run, Iso+Phe(high) and Iso+Phe(low) groups. These results suggest that hemodynamic change alone does not contribute to post-exercise modulation of BRS, while hemodynamic change or sympathetic activation during exercise contributes to post-exercise hypotension associated with a reduction of sympathetic activity.
Asunto(s)
Barorreflejo/fisiología , Hipertensión/fisiopatología , Condicionamiento Físico Animal/fisiología , Animales , Presión Sanguínea/fisiología , Cardiotónicos , Frecuencia Cardíaca , Isoproterenol , Masculino , Fenilefrina , Ratas , Ratas Endogámicas SHRRESUMEN
BACKGROUND: This study was designed to evaluate the effects of low-frequency electrical stimulation (LFES) on muscle strength and blood flow in patients with advanced chronic heart failure (CHF). METHODS AND RESULTS: Patients with CHF (n=15; age 56.5 +/- 5.2 years; New York Heart Association III - IV; ejection fraction 18.7 +/- 3.3%) were examined before and after 6 weeks of LFES (10 Hz) of the quadriceps and calf muscles of both legs (1 h/day, 7 days/week). Dynamometry was performed weekly to determine maximal muscle strength (F(max); N) and isokinetic peak torque (PT(max); Nm); blood flow velocity (BFV) was measured at baseline and after 6 weeks of LFES using pulsed-wave Doppler velocimetry of the right femoral artery. Six weeks of LFES significantly increased F(max) (from 224.5 +/- 96.8 N to 340.0 +/- 99.4 N; p<0.001), and also PT(max) (from 94.5 +/- 41.5 Nm to 135.3 +/- 28.8 Nm; p<0.01). BFV in the femoral artery increased after 6 weeks from 35.7 +/- 15.4 cm/s to 48.2 +/- 18.1 cm/s (p<0.05); BFV values at rest before and after 6 weeks of LFES did not differ significantly. CONCLUSIONS: LFES may improve muscle strength and blood supply, and could be recommended for the treatment of patients with severe CHF.
Asunto(s)
Circulación Coronaria/fisiología , Estimulación Eléctrica , Insuficiencia Cardíaca/fisiopatología , Corazón/fisiopatología , Resistencia al Corte , Biomarcadores/sangre , Velocidad del Flujo Sanguíneo , Índice de Masa Corporal , Proteína C-Reactiva/análisis , Enfermedad Crónica , Femenino , Insuficiencia Cardíaca/sangre , Insuficiencia Cardíaca/terapia , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/fisiopatología , Función Ventricular IzquierdaRESUMEN
1. We investigated whether chronic suppression of the renin-angiotensin system, which is known to be associated with reductions in microvascular density and vasodilator responsiveness of skeletal muscle, could affect exercise capacity in normotensive rats. 2. Rats were placed on normal rat chow, normal rat chow with captopril (100 mg/kg per day) or a high-salt diet (HS; 4%) for 4 weeks. Following these interventions, rats with indwelling carotid artery catheters were submitted to stepwise increasing exercise on a motor treadmill at a speed of 10, 20 and 30 m/min for 4 min while blood lactate was measured. 3. Blood lactate after exercise at a speed of 20 m/min was significantly higher and the duration during which rats were able to run at a speed of 30 m/min was significantly shorter in captopril-treated rats and rats fed an HS diet compared with control rats. 4. We conclude that chronic treatment with captopril or HS diet could reduce the exercise capacity in inactive normotensive rats, probably through chronic inhibition of the renin-angiotensin system.
Asunto(s)
Presión Sanguínea/efectos de los fármacos , Captopril/administración & dosificación , Prueba de Esfuerzo/efectos de los fármacos , Cloruro de Sodio Dietético/administración & dosificación , Animales , Presión Sanguínea/fisiología , Prueba de Esfuerzo/métodos , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
The purpose of this study was to examine the effects of chronic exercise training and angiotensin-converting enzyme (ACE) inhibition on peroxisome proliferator-activated receptor gamma (PPAR gamma) expression in fat and skeletal muscle in fructose-fed spontaneously hypertensive rats (SHR). SHR were fed a fructose-rich diet over 16 weeks of either exercise training (Ex group: 20 m/min, 0% grade, 60 min/day, 5 days/week), ACE inhibitor administration (TM group: temocapril, 10 mg/kg/day), or a combination of both treatments (TM+Ex group). The systolic blood pressure was reduced exclusively in the temocapril-treated groups. Serum leptin level was positively correlated with the ratio of epididymal fat weight to body weight (p<0.001). Exercise training significantly upregulated the PPARgamma expression in all tissues, which was attenuated by temocapril. PPARgamma expression was significantly upregulated in skeletal muscles in the Ex group, and temocapril administration attenuated this effect in the Ex+TM group. The level of PPARgamma protein was significantly higher in the extensor digitorum longus muscle than in the soleus muscle. Both TM and Ex prevented the fructose diet-induced transitions of fiber type. These data suggested that PPARgamma expression is tissue-specific, and that alterations in PPARgamma expression in the skeletal muscle induced by either or both treatments may have contributed to reducing the fat mass via the regulation of metabolic homeostasis. Changes in muscle morphology were independent of PPARgamma expression, and the higher proportion of type I fiber might also explain some of the beneficial impact of exercise and ACE inhibition on energy metabolism.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Músculo Esquelético/metabolismo , Esfuerzo Físico/fisiología , Receptores Citoplasmáticos y Nucleares/metabolismo , Tiazepinas/farmacología , Factores de Transcripción/metabolismo , Tejido Adiposo/metabolismo , Animales , Epidídimo , Fructosa/farmacología , Corazón/anatomía & histología , Resistencia a la Insulina , Masculino , Fibras Musculares de Contracción Lenta/citología , Fibras Musculares de Contracción Lenta/metabolismo , Músculo Esquelético/citología , Músculo Esquelético/efectos de los fármacos , Tamaño de los Órganos , Ratas , Ratas Endogámicas SHRRESUMEN
BACKGROUND: Exercise training or beta-blocker decreases high blood pressure (BP) and improves abnormal baroreflex function associated with hypertension. This study was undertaken to examine whether the effects of exercise training are additive to beta-blocker in spontaneously hypertensive rats (SHR). METHODS: At 5 weeks of age, SHR were allocated to four groups: sedentary control, exercise training, treatment with moderate dose of bisoprolol, and their combination. Systolic BP was monitored by the tail-cuff method under restrained conditions. Sigmoidal mean arterial pressure (MAP)-heart rate (HR) reflex curves were obtained in rats at 17 weeks of age under quiet conditions before and after atenolol to ensure sympathetic blockade and to determine the vagal component of gain. After studying baroreflex function, intrinsic HR was obtained by additional administration of atropine. RESULTS: Before atenolol, both exercise training alone and bisoprolol alone lowered resting MAP and HR, and decreased upper plateau (maximal tachycardia) and lower plateau (maximal bradycardia), resulting in decreased sympathetic component of HR range (upper plateau - intrinsic HR) and increased vagal component of HR range (intrinsic HR - lower plateau). After atenolol, both exercise training alone and bisoprolol alone increased the gain of vagal component. Exercise training had no additive effect on any parameters to bisoprolol except for systolic BP and HR measured by the tail-cuff method. CONCLUSIONS: Exercise training and bisoprolol have similar effects concerning resting hemodynamics and baroreflex function in SHR. Although additive effects of exercise training to bisoprolol are not evident under quiet, nonstressful conditions, some additive effects may be obtained under stress such as restrain.
Asunto(s)
Antagonistas Adrenérgicos beta/farmacología , Barorreflejo/efectos de los fármacos , Bisoprolol/farmacología , Presión Sanguínea/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Condicionamiento Físico Animal , Animales , Atenolol/farmacología , Barorreflejo/fisiología , Presión Sanguínea/fisiología , Peso Corporal , Frecuencia Cardíaca/efectos de los fármacos , Hipertensión/patología , Hipertensión/fisiopatología , Hipertrofia Ventricular Izquierda/patología , Masculino , Ratas , Ratas Endogámicas SHR , Cola (estructura animal)RESUMEN
The aim of this study was to evaluate the effects of moderate-intensity regular exercise and/or an angiotensin converting enzyme (ACE) inhibition on tumor necrosis factor-alpha (TNF-alpha) and glucose and lipid metabolism parameters. Spontaneously hypertensive rats (SHRs) were fed a fructose-rich diet during 16 weeks of either exercise training (Ex group: 20 m/min, 0% grade, 60 min/day, 5 days/week), administration of an ACE inhibitor (TM group: temocapril, 10 mg/kg/day), or a combination of both (TM+Ex group). The systolic blood pressure was reduced exclusively in the TM and TM+Ex group. Epididymal fat pads (EPI) weighed less in the TM+Ex group than in the single-treatment (TM) group. The serum leptin level was significantly and directly correlated with the EPI weight (p < 0.001). The TNF-alpha content per gram of EPI was the highest in the TM+Ex group. In addition, the EPI TNF-alpha level was negatively correlated with both the EPI weight and the serum leptin level (p < 0.001, respectively). In contrast, the TNF-alpha level of skeletal muscles was identical among the groups. The extensor digitorum longus had a significantly higher abundance of TNF-alpha protein than the soleus muscle. These data indicate that the local TNF-alpha expression is tissue-specific, and that upregulation of TNF-alpha in EPI by exercise training and/or ACE inhibition may have contributed to the reduction in fat cell volume via the induction of apoptosis and/or the regulation of metabolic homeostasis.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Fructosa/administración & dosificación , Hipertensión/sangre , Leptina/sangre , Actividad Motora/fisiología , Tiazepinas/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Animales , Presión Sanguínea , Dieta , Epidídimo , Miembro Posterior , Hipertensión/patología , Masculino , Músculo Esquelético/metabolismo , Miocardio/patología , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Endogámicas SHR , Sístole , Regulación hacia ArribaRESUMEN
We examined the effect of estrogen on pressor responses to an alpha1-adrenoreceptor agonist (phenylephrine) in conscious female Wistar-Kyoto rats. At the age of 11 weeks, rats underwent ovariectomy or a sham procedure. At the age of 15 weeks, ovariectomized (OVX) rats received intramuscular injection of estradiol valerate (EV) 5 microg (OVX+EV 5 microg group; n = 6), EV 25 microg (OVX+EV 25 microg group; n=7), or placebo (OVX group; n = 8), and sham-operated rats received placebo (sham group; n = 8). After 4 days, dose-pressor response curves to phenylephrine were examined under the condition where the renin-angiotensin, vasopressin and autonomic nervous systems were pharmacologically blocked. Ovariectomy shifted the dose-pressor response curve to phenylephrine leftward with a significantly decreased log ED50 (microg/kg) (the dose needed to reach 50% of the maximal response) (sham: 0.81 +/- 0.04; OVX: 0.57 +/- 0.05; p < 0.05). Supplementation with EV 25 mircog, but not EV 5 microg, reversed the dose-pressor response curve to phenylephrine in OVX rats to the level of the curve in sham-operated rats with a significantly increased log ED50 (microg/kg) (OVX+xEV 5 microg: 0.47 +/- 0.05; OVX+EV 25 microg: 0.75 +/- 0.08). These results suggest that the physiological level of estrogen seen in intact female rats attenuates pressor responses to alpha1-adrenoreceptor agonist, while supplementation with a moderate dose of estrogen is needed to restore such effects of physiological-level estrogen within a short-term period after chronic estrogen withdrawal.