预热处理对大鼠急性运动股四头肌保护作用的实验研究

The Study of Previous Heat Treatment on Protection in Rat Quadriceps Femoryafteries after an Acute Exercise

目的:通过观察预热处理前后大鼠急性运动股四头肌热休克蛋白70(HSP70)、超氧化物歧化酶(SOD)、丙二醛(MDA)的变化,探讨预热处理诱导HSP70表达对运动机体的保护作用.方法:三月龄雄性SD大鼠随机分为室温安静组、室温运动后即刻组、室温运动后3 h组、预热处理安静组、预热处理运动后即刻组、预热处理运动后3 h组.预热处理组进行热暴露处理后,室温恢复24 h后,运动组大鼠进行一次急性运动,运动后即刻和3h进行取样,对股四头肌HSP70的含量、SOD活性、MDA含量进行测试.结果:(1)预热处理安静组HSP70含量明显高于室温安静组(P<0.05)(2)室温组运动后即刻股四头肌HSP70有上升的趋势,但与安静组比较没有显著性的差异,预热处理组运动后即刻HSP70的含量与预热处理安静组比较有显著性的差异,运动后3 h,两组HSP70的表达都明显增加.(3)运动后即刻股四头肌SOD的活性明显升高,3 h后其活性降低,但与安静组比较仍具有显著性差异.在变化过程中预热处理组SOD活性高于室温组.(4)运动后即刻股四头肌MDA的含量明显升高,3 h后减少,在运动后前3 h,预热处理组MDA的清除比室温组迅速,有显著性差异.以上结果表明预热处理诱导HSP70的大量表达可提高运动时SOD活性,降低MDA的含量.提示HSP70可能会提高机体的抗氧化能力,减少自由基对机体的损害,对运动机体具有一定的保护作用.

The purpose of this study was to test the hyperthermic treatment on free radical metabolism in rat quadriceps femories by comparing heat shock protein70 （HSP70）, superoxide dismutase （SOD）, Malonldehyde （MDA） during the same condition after an acute exercise. Adult （3 months old） SD rats were divided into six groups： normothermic sedentary （Norm sed）, normothermic exercise Oh （Norm Exe Oh）, normothermic exercise 3h （Norm Exe 3h）, heat stress sedentary （Heat Sed）, heat stress exercise Oh （Heat Exe Oh）, heat stress exercise 3h （Heat Exe 3h）, .The rats were heated until the rectal temperature reached 42℃ for 15 min. Then the rats of Heat Sed were at rest under the normal temperature for 24h. Norm sed and Heat Sed were killed immediately, Norm Exe and Heat Exe ran on a treadmill for one hour. The rats were killed quadriceps femories were sampled to analyze HSP70, SOD, MDA. The results were as follows： （1） hsp70 content in HS were significantly higher than those in NS （P 〈 0.05） ; （2） HSP70 content remained unchanged immediately pestexereise for Norm sed, compared with Norm sed, HSP70 content increased significantly immediately.postexercise in Heat Sed, After 3h, HSP70 content both increased significantly; （3） SOD activity in quadriceps femories elevated significantly immediately after an acute exercise. Its activity decreased after 3h; （4） MDA content increased immediately postexercise. Its content decreased after 3h. Compared with Norm sed, the MDA is eliminated more easily in Heat Sed. These finds demonstrated HSP70 was probably involved in eliminating free radicals and improving antioxidative ability when exercise stress.