Physical training ameliorates chronic alcohol-induced hypertension and aortic reactivity in rat

Abstract

Aims: The aim of this study was to investigate the interactive effect of physical training and chronic ethanol ingestion on changes in blood pressure (BP) and aortic reactivity response in rats. Methods: Male Fisher rats were divided into four groups of seven animals each and treated as follows: (i) control (5% sucrose, orally) daily for 12 weeks; (ii) ethanol (4 g kg-1, orally) daily for 12 weeks; (iii) exercise training on treadmill followed by sucrose daily for 12 weeks; (iv) exercise training on treadmill followed by ethanol daily for 12 weeks. The body weight and BP were recorded every week. The animals were anaesthetized with pentobarbital after 12 weeks; blood and thoracic aorta were isolated and analysed for ethanol and reactivity response using tissue bath technique, respectively. Results: The data show that exercise training significantly lowered the weight gain 6-12 weeks in ethanol-treated rats compared to ethanol alone or control rats. The systolic and mean BP significantly elevated 6-12 weeks, whereas diastolic BP elevated 8-12 weeks after ethanol ingestion. Exercise training lowered the BP close to the normal control values in ethanol fed rats. Blood ethanol level significantly elevated in ethanol group but decreased in exercise plus alcohol group. Aortic contractile response to phenylephrine in ethanol or control groups was attenuated by training with or without intact endothelium. Ethanol significantly reduced the aortic relaxation response to acetylcholine whereas training enhanced the relaxation response with intact endothelium. The relaxation responses to adenosine and sodium nitroprusside in the aortic ring segments of rats with or without endothelium were decreased in ethanol group which were attenuated by exercise training. Conclusions: Physical training attenuates the chronic ethanol-induced hypertension via reduction of body weight, clearance of ethanol, and augmentation of the aortic endothelial relaxation response in rats. © 2006 Oxford University Press.