Exercise training effects on vascular reactivity and metabolic parameters of high caloric-fed Wistar rats
© Zanesco et al; licensee BioMed Central Ltd. 2007
Published: 25 July 2007
An impairment of relaxing response to a variety of agonists is observed in vascular smooth muscle from animals submitted to a consumption of high energy diets. This reduction has been associated with endothelial dysfunction. Additionally, the beneficial effect of exercise training on the cardiovascular disease has been associated with improvement of nitric oxide bioavaiability.
The aim of this study was to investigate the preventive effect of exercise training on vascular reactivity of rat aortic rings submitted to hyper caloric diet.
Male Wistar rats were divided into four groups: Sedentary (SD); Trained (TR); Sedentary diet (SDD) and Trained diet (TRD). Trained groups were submitted to physical preconditioning for 4 weeks. After that, the animals were treated with normal chow or cafeteria diet for further 8 weeks concomitantly with exercise. Training sessions consisted of run in a treadmill at intensity between 70–80% VO2max during 60 min, 5 days/week for 12 weeks. After an overnight fasting, rats were sacrificed and serum levels of triglycerides, glucose and plasmatic nitrite/nitrate concentration were measured by commercial kits. Insulin concentration was measured by radioimmune assay. Aortic artery rings were isolated and concentration-response curves to acetylcholine (ACh) in presence or absence of L-NAME and Sodium Nitroprusside (SNP) in presence or absence of ODQ were obtained. The potency (EC50) and maximal responses (Emax) were determined. Expression of eNOS, nNOS and CuZn SOD were detected by Western blotting.
Physical preconditioning improved the endothelium-dependent relaxing responses in aortic artery rings from hyper caloric fed rats and this response appers to be related to an improvement in NO bioavaiability.
Financial Support by FAPESP/CAPES.
This article is published under license to BioMed Central Ltd.