|（1.School of Physical Education，South China Normal University，Guangzhou 510006，China；2.Department of Physical Education，Huaihua University，Huaihua 418008，China）
Abstract: The purpose of this study was to examine the effcet of acute exercise and acute exercise after hyperther-mic treatment on hsp70 and oxidative stress markers SOD and MDA At the same time, we investigated hsp70 re-sponse changes to exercise.Adult male SD rats were divided into eight groups: normothermic sedentary (Norm sed), normothermic exercise 0 h (Norm Exe 0 h), normothermic exercise 3 h(Norm Exe 3 h), normothermic exercise 24 h (Norm Exe 24 h), heat stress sedentary (Heat Sed), heat stress exercise 0 h (Heat Exe 0 h), heat stress exercise 3 h (Heat Exe 3 h), heat stress exercise 24 h (Heat Exe 24 h). The rats were heated until the rectal temperature reached (41.5±0.5) ℃ for 15 min in oven.Then the rats of Heat Sed were at rest under the normal temperature for 24 h.The rats were killed according to specified time after acute treadmill running (velocity is 25 m/min, gradient is 0°, time is 60 min) and quadriceps femories were sampled to analyze HSP70, SOD, MDA.The results were as follows: HSP70 content had no significant change immediately postexercise(P>0.05), HSP70 content increased significantly After 3 h (P<0.05), and it returned to the basal level at 24 h(P>0.05). The HSP70 content is higher in Heat Sed than Norm Sed during the process(P<0.05)；SOD activity in quadriceps femories elevated significantly immediately after an acute exercise in both Seds(P<0.05). Its activity decreased after 3 h(P<0.05) and returned the basal level at 24 h. The SOD activity is higher in Heat Sed than Norm Sed during the process(P<0.05)；(4)MDA content increased immediately postexercise(P<0.05). Its content decreased, but still higher than Norm Exe 0 h Sed, after 3 h(P<0.05). Its content renuned the basal level at 3 h in Heat sed.MDA content returned the basal level at 24 h in Nrom sed. Compared with Norm sed, the MDA is eliminated more easily in Heat Sed(P<0.05). These finds demonstrated acute ecercise induced the expression of HSP70 and acute exercise after hyperthermic treatment can produce a cumulative effect of HSP70 .HSP70 is expressed largely by hyperthermic treatment may increase antioxidant capacity and re-duce oxidative stress damage caused by the exercise.
Key words: exercise biochemistry；HSP70；SOD；MDA；quadriceps femoryafteries；acute exercise