Effects Of High Temperature Pretreatment On HSP70,Anti-oxidative Systems And Ca～(2+)ATPase Of Hippocampal Gyrum In Rats Acute Exercise

Heat shock protein is a cell endogenous protector protein. Heat stress can induce the generous HSP70 express, acquired tolerance of the organism, enhance the sequentia tolerance of the second stimulate. Generous research confirmed, exercise can induce the HSP70 express of the organism, and the express of HSP70 could be induced in different part of the organism.The purpose of the study was to observe the HSP70 change of hippocampal in rats after different acute exercises, and the HSP70 changed immediate postexercise;After heat shock pretreatment, HSP70 changed in exercise, at the same time detected the SOD,MDA,Ca²⁺-ArPase level in hippocampal to approach the organism protection of the express of HSP70 by heat shock pretreatment.Adult male SD rats were divided into six groups:normothermic sedentary(NS),normothermic 15m/minexercise(NS15),normothermic 27m/min exercise(NS27), heat shock pretreatment sedentary(HS),heat shock pretreatment 15m/min exercise(HSl5),heat shock pretreatment 27m/min exercise(HS27).The normothermic groups didn' t carry out the heat shock pretreatment, the heat shock pretreatment groups rats restored 24 hours after the heat shock pretreatment in room temperature, then all the exercise groups did the acute exercise and sampled after the exercise instantly to determine the SOD, MDA and Ca²⁺-iTPase, while the sedentary groups determine the SOD, MDA and Ca²⁺-iTPase sampled directly, and compare all the groups.Results:(1)No matter normothermic sedentary groups or heat shock pretreatment sedentary groups, in invariably degree, HSP70 expression in hippocampal increased while the intensity increased, but only the HS27 had significant with NS(P＜0.05).The content of HSP70 in hippocampal in heat shock pretreatment groups were higher than normothermic groups(P＜0.05).(2) Though the SOD activity in hippocampal had upgrade tendency after exercise, there were no significant different in normothermic sedentary groups or heat shock pretreatment sedentary groups(P＞0.05).The SOD activity in hippocampal in heat shock pretreatment groups were higher than normothermic groups(P＜0.01).(3)No matter normothermic sedentary groups or heat shock pretreatment sedentary groups, the value of MDA in hippocampal in every exercise groups had no significant different(P＞0.05).Compared to normothermic sedentary groups, the value of MDA in hippocampal of heat shock pretreatment sedentary groups had decrease tendency(P＞0.05).(4) In invariably degree, the Ca²⁺-ATPase activity in hippocampal of both normothermic sedentary groups or heat shock pretreatment sedentary groups decreased while the exercise intensity increase (P＜0.05) .The Ca²⁺-ATPase activity in hippocampal in heat shock pretreatment groups were higher than normothermic groups(P＜0.05).Conclusion:(l)Compared to NS, the HSP70 content of NS15 had upgrade tendency, and NS27 was higher than NS significantly (P＜0.05).Result confirmed that acute exercise induced the increase of HSP70 content, and the HSP70 expression was related to exercise intensity.(2)Heat shock pretreatment could step to induce the HSP70 expression, the HSP70 content of heat shock pretreatment groups were all higher than the same intensity normothermic sedentary groups significantly(P＜0.05).The double stimulate of heat shock pretreatment and exercise had additive effect to HSP70 expression in hippocampal,while the intensity was larger, the additive effect was larger.(3)Heat shock pretreatment can strengthen the SOD activity very significantly(P＜0.01).Compared to the same intensity normothermic sedentary groups, the value of MDA has decrease tendency(P＞0.05).Result cued that, heat shock pretreatment could elevate the antioxidase of hippocampal, to oppose the free radical injure.(4)One time different intensity acute exercise induced the depress of the Ca²⁺-ATPase activity in hippocampal, and depressed by the increase of the intensity, cued that hippocampal might be injured, while the intensity larger, the injury is heavier(P＜0.05).Heat shock pretreatment caused that the Ca²⁺-ATPase activity in hippocampal in HS27 upgraded significantly than NS27.