RESUMEN
Objective:To observe any effect of regular aerobic exercise on cardiac remodeling in spontaneously hypertensive rats (SHR) and explore the mechanism of endothelial nitric oxide synthase (eNOS) uncoupling.Methods:Thirty 6-week-old healthy male SHR were divided into a sedentary group and an exercise group, each of 15. Another ten age- and sex-matched Wistar-Kyoto rats were set as a normal control group. The animals in the normal control and sedentary groups were fed quietly in their cages, and those in the exercise group performed moderate intensity treadmill exercise for 8 weeks (5 times per week). Forty-eight hours after the last training, echocardiography was applied to document cardiac structure and function in both groups. Wheat germ agglutinin staining and Picrosirius Red staining were used to obtain the cardiomyocyte cross sectional areas (CSAs) and interstitial collagen volume fractions (CVFs) of all of the mice. The rates of cardiomyocyte apoptosis were measured using TUNEL staining, and myocardial tetrahydrobiopterin (BH4) content was measured using high-performance liquid chromatography. Total eNOS, eNOS dimer and eNOS monomer protein expression in the myocardia were detected using western blotting.Results:Compared with the normal control group, the left ventricular wall thickness (LVWT), myocardial CSA, CVF, apoptosis of cardiomyocytes and eNOS monomer levels were significantly higher in the sedentary group, on average. But the end-diastolic diameter (LVEDD) and ejection fraction (LVEF) of the left ventricle and the levels of eNOS dimer and myocardial BH4 and the eNOS dimer/monomer ratio tended to be lower. Comparing the exercise group with the sedentary group, the average LVEDD, LVEF, eNOS dimer, eNOS dimer/monomer ratio and myocardial BH4 content were significantly higher in the exercise group, but the myocardial CVF, cardiomyocyte apoptosis and eNOS monomer levels were significantly lower. LVWT and CSA were not significantly different. There were no significant differences in the total eNOS protein levels among the three groups.Conclusion:Regular aerobic exercise might improve cardiac remodeling in cases of spontaneous hypertension regulating eNOS uncoupling, at least in rats.
RESUMEN
Objective:To explore the effect of regular aerobic exercise on oxidative stress, inflammatory reaction and apoptosis with a rat model of colitis.Methods:Forty-five C57BL/6 mice were randomly divided into a control group, a model group and a model exercise group, each of 15. Colitis was induced in the rats of the model and model exercise groups through administration of 3.5% sodium dextran sulfate. The control group and the model group were kept quiet in their cages, while the model exercise group performed voluntary wheel running for 8 weeks after the successful modelling. Any histopathological changes in the colon tissue were observed after hematoxylin and eosin staining. Oxidative stress, inflammatory reaction and apoptosis were measured from colon tissue homogenates.Results:Compared with the control group, the average expression of the tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6 and prostaglandin E2 (PGE2) as well as levels of reactive oxygen species (ROS), malondialdehyde (MDA) and nitric oxide (NO) and inducible nitric oxide synthase (iNOS) and Caspase-3 activity and the protein expression of cyclooxygenase 2 (COX2), nuclear factor kappa B (NF-κB) p65, apoptosis inducing factor (AIF), cytochrome c (Cyt C) and Bax had all increased significantly in the other two groups, while the levels of IL-10 and glutathione (GSH), the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) and the protein expression of Bcl-2 protein had decreased significantly in the model group. Compared with the model group, the average content of TNF-α, IL-1 β, IL-6, PGE2, ROS, MDA and NO, the activity of iNOS and Caspase-3 and the protein expression of COX2, NF-κB p65, AIF, CytC and Bax had decreased significantly, while that of IL-10 and GSH, the activity of SOD and GPx and the protein expression of Bcl-2 protein had increased significantly in the model exercise group.Conclusion:Regular aerobic exercise has a protective effect against colitis through improving oxidative stress, inflammation and apoptosis, at least in rats.