运动对胰岛素抵抗大鼠内皮依赖性血管舒张功能干预效应的研究

Effect of exercise on endothelial-dependent vasodilatation in insulin-resistant rats

目的 探讨运动对高脂膳食诱导胰岛素抵抗 (IR)大鼠内皮依赖性血管舒张功能(EDVR)的干预效应及其发生机制。 方法 特殊高脂膳食喂养 4周 ,建立 IR动物模型。游泳运动前后以钳夹技术观察 IR大鼠胰岛素敏感性、大鼠离体主动脉条对乙酰胆碱 (Ach)依赖性血管舒张功能的反应及其大鼠主动脉的一氧化氮合成酶 -一氧化氮 -环岛苷酸 (NOS- NO- c GMP)环功能状态。 结果 (1 )运动后 IR大鼠葡萄糖输注率 (GIR)显著高于非运动 IR大鼠 (P<0 .0 5 ) ,正常大鼠运动前后GIR水平无明显变化。(2 ) IR大鼠运动后离体主动脉条对 Ach依赖性血管舒张功能反应显著改善 ,最大舒张反应升高达 1 9.4 3% (P<0 .0 1 ) ,正常大鼠运动后离体主动脉条对 Ach依赖性血管舒张功能反应也明显改善 ,最大舒张反应升高达 1 4 .78% (P<0 .0 5 )。 (3) IR大鼠运动后主动脉 NO及 c GMP水平增加 (P<0 .0 5 )。大鼠主动脉条对 Ach依赖性血管舒张反应与 NO浓度呈显著负相关 (r=- 0 .6 4 9,P<0 .0 5 )。 结论 运动能改善 IR大鼠胰岛素敏感性及内皮依赖性血管舒张功能 ,运动可增加 IR大鼠主动脉 NO及 c GMP水平 ,提示运动是一个从改善血管内皮功能入手 ,干预治疗

Objective To investigate the effect of exercise on endothelial dependent vasodilatation in insulin resistant rats. Methods IR rat model was created by high fatty diet and IR was evaluated with golden standard clamp forceps technique. After swimming for 4 weeks insulin sensitivity was evaluated, the function of Ach dependent vasodilatation of isolated aorta of IR and normal rats was estimated, and the functional status of NOS NO cGMP cycle of rat aorta was researched. Results (1) After swimming for 4 weeks GIR of the IR rats was obviously higher than non exercise IR rats ( P <0.05). (2) After swimming for 4 weeks the response of IR rat aorta to Ach dependent vasodilatation increased markedly. The maximum dilating response increased by 19.43%( P <0.01). The response of normal rat ex aorta to Ach dependent vasodilatation increased markedly too, and its maximum dilating response increased by 14.78% ( P <0.05). (3) After swimming for 4 weeks the concentrations of NO and cGMP in the aorta of IR rats were increased than those of non exercise rats(p<0.05). Significant negative correlation was also observed between the response of rat aorta to the function of Ach dependent vasodilatation and the level of NO ( r=-0.649, P <0.05). Conclusion Exercise increases insulin sensitivity and improves endothelial function of IR rats created by high fatty diet. The change of endothelial function in IR rats was related to the disequilibrium of NO cGMP cycle.