游泳训练对糖尿病大鼠主动脉血管内皮依赖性舒张功能的改善及机制

Effects of swimming training on endothelium-dependent vasodilation function of aorta in diabetic rats and its mechanisms

目的:观察游泳训练对糖尿病大鼠血管内皮依赖性舒张功能的影响及其可能机制。方法:40只健康雄性SD大鼠随机分为正常对照组(CG),糖尿病对照组(DCG),糖尿病游泳组(DSG)。游泳训练8周后,取胸主动脉,离体灌流法检测其对乙酰胆碱(ACh)诱导的内皮依赖性舒张反应,及其对硝普钠(SNP)诱导的非内皮依赖性舒张反应。并测定血清一氧化氮(NO)浓度及血清葡萄糖、胰岛素、总胆固醇、甘油三酯、氧化应激状态(超氧化物歧化酶,谷胱甘肽过氧化物酶,丙二醛)。结果:糖尿病组大鼠胸主动脉对ACh诱导的舒张反应明显减弱(P<0.05);游泳运动能明显改善糖尿病胸主动脉内皮依赖性舒张反应;各组对SNP诱导的非内皮依赖性舒张反应无显著差异。糖尿病组的NO浓度低于正常组(P<0.05),游泳运动显著提高了糖尿病大鼠的NO浓度。与糖尿病组相比,糖尿病游泳组大鼠血糖、胰岛素敏感性、脂质代谢改善,同时氧化应激状态显著降低。结论:游泳运动能明显改善糖尿病大鼠胸主动脉对ACh诱导的内皮依赖性舒张反应,其机制可能是通过降低血糖,降低氧化应激,增加NO的生物活性来实现的。

Objective： To investigate the effects of swimming training on endothellum-aepenclent vasoaliauon runcuon of aorta in diabetic rats and to explore it＇s possible mechanism. Method：Forty male SD rats were assigned into normal control group（CG）, diabetic control group（DCG） and diabetic swimming group（DSG）. After 8 weeks swimming, aortic rings were isolated for recording vascular tension in vitro; end othelium-dependent dilation induced by acetylcholine （ACh） and endothelium-independent dilation induced by sodium nitroprusside（SNP） were measured. The serum NO levels were determined by Griess reaction. The serum glucose, insulin, total cholesterol（TC）, triglycerides（TGs）, malondialdehyde（MDA）, glutathione peroxidase（GSH-Px）, superoxide-dismutase（SOD） were detected. Result： In diabetic group endothelium-dependent vasodilation reaction of aorta induced by Ach was significantly weakened（P〈0.05）. In diabetic swimming group endothelium-dependent vasodiation reaction of aorta could be amelibrated significantly. However, the endothelium-independent vasodilation reactions induced by SNP were not significantly different in aorta of all groups（P〉0.05）. The NO levels of diabetic group were significantly lower（P〈0.05）, In diabetic swimming group NO levels improved significantly（P〈0.05）. Compared with diabetic group, in-diabetic swimming group glycaemia and insulin showed amelioration, accompanied by remarkable reduction of oxidative stress. Conclusion： Swimming can improve the aortic endothelium-dependent vasodilation reaction in diabetic rats, which involved the improvement of hyperglycemia, the reduction of oxidative stress, and increasing NO bioavailability. Author＇s address The Sport College of Shi Jia Zhuang College, Hebei, Shijiazhuang, 050035.