耐力训练上调SD大鼠主动脉AMPK和eNOS表达并改善血管内皮功能

Endurance Training Upregulated Aorta AMPK and eNOS Expression and Improved Vascular Endothelium Function in SD Rats

目的:观察长期耐力训练对大鼠主动脉AMPK和eNOS表达、NO含量以及内皮依赖性血管舒张反应的影响,探讨耐力训练改善血管内皮功能的可能机理。方法:30只SD大鼠随机分为对照组(n=15)和运动组(n=15)。运动组进行为期8周的跑台运动,对照组保持安静状态。实验结束后,实时荧光定量PCR测定主动脉AMPK、eNOS mRNA水平,western blot检测主动脉AMPK、eNOS总蛋白及磷酸化蛋白水平,硝酸还原酶法检测主动脉与血浆NO含量,离体血管张力记录法测定乙酰胆碱(Ach)诱发的内皮依赖性血管舒张反应,递增负荷运动实验测定大鼠力竭运动时间。结果:与对照组比较,运动组大鼠力竭时间延长(P<0.01),胸主动脉对各浓度(10~6 mol/L^10~9 mol/L)Ach的舒张百分比升高(均为P<0.01),主动脉与血浆NO含量升高(均为P<0.01),主动脉AMPKα、eNOS mRNA、总蛋白以及磷酸化蛋白水平均显著升高(均为P<0.01)。结论:长期耐力训练上调主动脉AMPK和eNOS活性和表达量,促进NO产生,从而改善了血管内皮功能并提高运动耐力。

Objective：To observe the effects of long-term endurance training on expression of AMPK and eNOS of aorta, content of NO and response of endothelium-dependent vasodilatation in rats and to explore the possible mechanism of exer- cise-induced vascular endothelium function improvement. Methods： Thirty SD rats were randomly divided into control group （n = 15 ） and exercise group （n = 15 ）. Rats in exercise group performed an 8-week treadmill exercise while those in control group retained their own daily activity. After experiment, aortic AMPK and eNOS mRNA were determined by real- time fluorescent quanfitation PCR, total and phosphorylated protein of AMPK and eNOS by western blot, and NO in aorta and plasma by method of nitrate reductase, the response of endothelium-dependent vasodilatation was treated with acetyl- choline （Ach） and evaluated by isolated vascular tension records system and exhaust time by incremental treadmill test. Results ： Exhausting time was prolonged （ P 〈 0. 01 ）, relaxation percentage of thoracic aorta to Ach （ 10 - 6 mol/L ~ 10 ~ 9 mol/L） was elevated （ all P 〈 0. 01 ）, NO in aorta and plasma was raised （both P 〈 0. 01 ）, and aortic AMPKa and eNOS mRNA,total protein and phosphorylated protein level increased （all P 〈 0.01 ）. Conclusion： Long-tern aerobic exercise training upregulated activity and gene expression of AMPK and eNOS, and promoted NO production in vessel, thus impro- ving vascular endothelium function and enhancing exercise tolerance.