Synthesis of Hsp72 induced by exercise in high temperature

An investigation was undertaken involving the physiological effects of exercise in high temperature and its effect on the induction of heat shock proteins synthesis in peripheral lymphocytes and gastrocnemius. Male Long-Evans rats were employed. Environmental temperature was designed as three conditions: room temperature (26-27 degrees C), middle temperature (30-31 degrees C), and high temperature (36-37 degrees C). Rats were divided into one of three groups and exercised passively in an automatic round treadmill. Body temperature, biochemical changes were determined and the synthesis of heat shock protein 72 were analyzed by SDS-PAGE and immunochemical stain with monoclonal anti-Hsp72 antibody. Those results indicated that the body temperature elevated faster and higher in rats of high-temperature exercise group than those of a house temperature significantly (p < 0.05). Hsp72 could be detected only in lymphocytes from rats exercising in high temperature more than 60 minutes whose body temperatures were elevated above 41 degrees C. The induced Hsp72 appeared in lymphocytes 2 hours after exercise and reached maximally at 16-24 hours and then disappeared gradually. In gastrocnemius, Hsp72 could be detected even before the passive exercise, and its amount changed as in lymphocytes did in all three groups. No difference was found in blood sugar, hematocrit and CK among the three groups of rats. On the basis of above results, we can conclude that Hsp72 is synthesized in the muscle of intact rats, and exercise is a sufficient inducer. For lymphocytes, the presence of Hsp72 can be viewed as a heat stress in exercise.