运动训练对不同功能状态下大鼠骨骼肌一氧化氮含量及一氧化氮合酶活性的影响

Influence of exercise training on content of nitric oxide and activity of nitricoxide synthase in skeletal muscles of rats at different functional status

目的:观察大鼠在不同功能状态运动训练下骨骼肌一氧化氮含量及一氧化氮合酶活性的变化情况,探讨运动训练对机体自由基代谢的影响。方法:实验于2003-04/06在曲阜师范大学体育科学院生理实验室完成。选取雄性Wistar大鼠56只,随机分为2组,即对照组和训练组,每组28只。训练组大鼠进行8周的跑台训练,训练时间40～60min,每周6d。训练结束后,各组大鼠分别在圆形塑料桶中进行2d适应性游泳,每天15min。第3天,两组大鼠分别于安静状态、定量负荷运动(尾部负重,在塑料桶中游泳,迫使大鼠不断游动40min)后、力竭运动(尾部负重,在塑料桶中游泳,迫使大鼠不断游动,至大鼠沉入水面下10s不能自主浮出水面,且放在平板上无法完成翻正反射为止)后即刻、力竭运动24h后麻醉处死,每个时相点7只大鼠。分别测定各组大鼠不同时相点骨骼肌中一氧化氮含量和一氧化氮合酶活性。结果:56只大鼠全部进入结果分析,无脱失。①各组大鼠不同时相点骨骼肌中一氧化氮含量比较:安静状态下,训练组大鼠骨骼肌中一氧化氮含量显著高于对照组(t=-2.42,P<0.05)。与安静状态相比,对照组大鼠在定量负荷运动后骨骼肌中一氧化氮含量显著升高(t=-4.60,P<0.01)。②各组大鼠不同时相点骨骼肌中一氧化氮合酶活性比较:安静状态下,训练组大鼠骨骼肌中一氧化氮合酶活性显著高于对照组(t=-2.81,P<0.05)。与安静状态相比,对照组大鼠在定量负荷运动后、力竭运动后即刻以及力竭运动恢复24h后骨骼肌中一氧化氮合酶活性显著升高(t=-2.56,-2.25,-2.51,P<0.05)。结论:运动训练能够提高大鼠安静状态下骨骼肌中一氧化氮的含量和一氧化氮合酶的活性,但运动训练不同功能状态下一氧化氮含量与一氧化氮合酶活性的变化不甚一致,说明体内一氧化氮含量除受一氧化氮合酶活性的制约外,可能还受其他因素的影响。

AIM： To observe the changes of nitric oxide content and nitricoxide synthase （NOS） activity in rats＇ skeletal muscles at exercise training of different sports appearance, and discuss the effect of movement training on organism free radical metabolism. METHODS： The experiment was conducted in the Physiological Laboratory of Physical Education Sciences Academy of Qufu Normal University between April and June 2003. Totally 56 male Wistar rats were selected and randomly divided into 2 groups： control group and training group with 28 rats in each group. The rats in the training group were doing 8-week treadmill training for 40-60 minutes for 6 days. After training, the rats in each group were doing 2-day adaptive swimming in round plastic bucket, 15 minutes every day. At the 3^rd day, the rats were killed at resting state, fixed quantitative load exercise （weight loading at tail, swimming in plastic bucket, the rats were urged to swim for 40 minutes continuously）, exhausted exercise （weight loading at tail, swimming in plastic bucket, the rats were forced to swim, till the rats sunk into water for 10 s and could not emerge by them-selves, and unable to do righting reflex on flat plate） immediately, at 24 hours after exhausted exercise, 7 rats in each phase. Content of nitric oxide and activity of NOS in skeletal muscle of rats of each group were detected at different phase. RESULTS： Totally 56 rats were involved in the analysis of result, without drop out. （1）Comparison of content of nitric oxide in skeletal muscle of rats in each group at different phase： The content of nitric oxide in skeletal muscles of rats in the training group was obviously higher than that in the control group （t= -2.42,P 〈 0.05）. The content of nitric oxide in skeletal muscles of rats in the control group after fixed quantitative load exercise markedly in creased as compared with that in resting state （t= -4.60,P 〈 0.01 ）. （2） Comparison of activity of NOS in skeletal muscle of rats in each group： The activity in rats of the training group under resting state was remarkably higher than that of the control group （t= -2.81 ,P 〈 0.05）. Compared with the resting state, the activity of NOS in skeletal muscle after fixed quantitative load exercise, immediately after exhausted exercise and 24 hours after exhausted exercise distinctly increased （t=-2.56,-2.25, -2.51 ,P 〈 0.05）. CONCLUSION： The exercise training can improve the content of nitric oxide and the activity of NOS in skeletal muscles of rats in resting state, but the changes of the content of nitric oxide and the activity of NOS are different in different functional status of exercise training, which suggests that the content of nitric oxide is not only limited by the activity of NOS, but also by other factors.