Objective To explore the effect of cold restraint stress on heart and liver of rats,the expression of HSP70 and the levels of CK and ALT in serum was studied. Methods 77 SD rats of 50 days old were randomly divided into 7 groups,namely 0 h,0. 5 h,1. 0 h,1. 5 h,2. 0 h,2. 5 h,3. 0 h group. The cold-restrained rats lasted the corresponding time,then the distributions of HSP70 in heart and liver tissues were examined by means of immunohistochemistry method and the level of CK and ALT in serum was determined. Results (1)The HSP70 expression in heart increased with stress time 1. 5 h group had an obvious increase compared with the 0 h group ( P 0. 05),and after 2. 0 h group,the increase was more significant. (2)The HSP70 expression in liver increased slowly with stress time. Only 3. 0 h group had an obvious increase compared with the 0 h,0. 5h and 1. 0h group (P 0. 05). (3)The level of CK rose quickly at the beginning stage of the stress,then changed smoothly. The level of ALT in serum rose with stress time,during the first 2. 5 h changed smoothly but significantly increased at 2. 5 h group. Conclusion The cold restraint stress could induce the expression of HSP70 in heart and the level of CK in serum markedly increasing in a short time,and increased with stress time,while the expression of HSP70 in liver and the level of ALT in serum had no markedly change in a short time,only after 3 hours the increase became obvious,it suggests that heart is more sensitive to the cold restraint stress,while liver has more powerful resistance.

Objective:To study the dynamic effects of cold restraint stress on HSP70 expression in kidney and serum corticosteroid content in rats,and explore its possible mechanism.Methods:Seventy-seven 50-day-old SD rats were randomly divided into 7 groups,namely 0 h,0.5 h,1.0 h,1.5 h,2.0 h,2.5 h and 3.0 h group.At corresponding restraint stress time,the expression of HSP70 in kidney tissues were tested by means of immunohistochemistry and the level of CORT in serum was also examined.Results:The level of CORT reached its peak in 1.5 h group,but there was no significant difference in other groups.Under the light microscope,the expressions of HSP70 in the nuclei of renal glomerular capillary endothelial cells,in the nuclei and cytoplasm of renal tubular epithelial cells could be observed.The HSP70 expression in kidney increased continuously first,then it was kept in a high level at stress time of 1.5 h,2.0 h and 2.5 h(P0.01),and since then it declined gradually(P0.05).Conclusion:Suitable cold restraint stress can induce the synthetic of HSP70,and it increased with stress time.While excessive cold restraint stress may decreased or block the expressions of HSP70 in kidney.

目的 研究拘束冷应激对大鼠血清中促肾上腺皮质激素(ACTH)、皮质醇(CORT)、肌酸激酶(CK)和丙氨酸转氨酶(ALT)浓度的动态变化及可能的机制.方法 50日龄清洁级大鼠56只,随机分为7组,即0、0.5、1.0、1.5、2.0、2.5和3.0h组.采用拘束冷应激法,在应激相应的时间后,检测大鼠血清中ACTH、CORT、CK、ALT浓度和胃溃疡指数的测定.结果 ①大鼠血清中的ACTH浓度随着应激时间的增加呈现迅速升高的趋势,0.5 h达到最高值,之后又迅速下降,逐渐趋于平缓;②血清中的CORT浓度呈现逐渐升高的趋势.1.5 h达到最高值,之后又迅速下降,逐渐趋于平缓;③血清中的CK和ALT活力显著升高,且随着冷应激时间的增加而递增;④大鼠胃溃疡指数在应激初期呈现迅速升高的趋势,2.5 h时达到最高值.结论 拘束冷应激可使大鼠血清中的ACTH和CORT的浓度上升,至最高值后迅速下降;而血清中CK和ALT的浓度则随着拘束冷应激时间的增加而递增.拘束冷应激导致大鼠发生急性胃溃疡,应激2.5 h时最严重,提示拘束冷应激大鼠模型的造模时间以2.5 h为最佳.