【摘要】 目的:观察热休克蛋白HSP70对大鼠IL1β性发热反应的影响,并研究其与脑内精氨酸升压素(AVP)含量变化的关系,以探讨HSP70是否参与热限作用。方法:(1)60只大鼠随机分为热应激(HS)处理组(A组)和经热应激处理前10min加用放线菌酮(CHX)组(B组),Western印迹法观察热应激处理后0、4、8、12、16h各自下丘脑内HSP70的表达水平。(2)24只大鼠随机分为4组:①HS+IL1β组,经热应激处理后,在HSP70表达最高时,向其下丘脑视前区(POA)注射IL1β;②CHX+HS+IL1β组,于应激前10min腹腔注射CHX;③IL1β组,仅注射IL1β;④对照组,仅注射1μl生理盐水。连续观察体温变化指标8h,绘制体温变化曲线。(3)30只大鼠按方法(2)分为4组及HS组(只进行热应激处理,不注射IL1β);测定体温变化曲线中体温高峰时各自脑内AVP含量。结果:(1)各时间点A组HSP70水平均显著高于B组(P<0.01),A组4、8、12、16h的HSP70表达水平显著高于0h,其中12h的表达水平最高(P<0.01)。(2)IL1β注射后15min,体温开始升高,120min达发热高峰。HS+IL1β组各时间点的体温变化指标与IL1β组有显著差异(P<0.05,P<0.01),高表达的HSP70能明显抑制IL1β性发热的幅度。单独注射IL1β120min时VSA中AVP的含量明显高于对照组和HS+IL1β组(P<0.05),而与CHX+HS+IL1β组无显著差异。各组间大鼠体温高峰期下丘脑中AVP的含量均无显著变化。结论:高水平表达的HSP70能抑制IL1β性发热;HSP70对IL1β性发热的抑制作用是否与VSA中AVP含量的变化有关,是否参与了大鼠的热限作用仍待进一步探讨。更多还原

【Abstract】 Objective:To observe the effect of HSP70 on IL-1β-induced febrile response and study its relation with the content of arginine vasopressin(AVP) in the brain,so as to determine whether HSP70 takes part in febrile ceiling. Methods: (1)Sixty rats were equally randomized into 2 groups: heat stress group(group A) and cycloheximide (CHX) pretreated+heat stress group(group B).The rats of the 2 groups were killed on 0,4,8,12 and 16 h after heat stress preconditioning, and HSP70 in the hypothalamus was detected by Western blot. (2)Another 24 rats were equally randomized into 4 groups: HS+IL-1β group was injected with IL-1β into POA at peak time of HSP70 expression after heat stress preconditioning;CHX+HS+IL-1β group was injected with CHX into the abdominal cavity 10 min before heat stress; IL-1β group was injected with IL-1β only, and control group was injected with 1 μl normal saline. Difference of temperature(△T), maximum change of temperature(ΔT max) and thermal response index(TRI) were continously observed for 8 h and the curve of temperature change was plotted. (3)Another 30 rats were equally divided into the above-mentioned 4 groups and HS group(treated with heat stress preconditioning). The content of AVP was measured by radioimmunoassay at the peak temperature. Results: The expression of HSP70 was significantly higher in group A than in group B (P<0.01).HSP70 expression in group A was significantly higher 4,8,12,16 h later than that at 0 h, and the maximum expression was 12 h after heat stress preconditioning(P<0.01).The temperature began to elevate 15 min after the injection of IL-1β and reached the peak 2 h later. The temperature changes were significantly different between HS+IL-1β and IL-1β group(P<0.05,P<0.01),and IL-1β-induced fever was obviously inhibited by high level expression of HSP70. Two hours after injection of IL-1β,AVP content in VSA was significantly higher than that of control and HS+IL-1β groups(P<0.05), but was not significantly different from that of CHX+HS+IL-1β group. The change of AVP content in the hypothalamus was not obvious at peak time of fever in each group.Conclusion: High level expression of HSP70 can inhibit IL-1β-induced fever, and whether this is related to the content change of AVP in VSA and whether this takes part in febrile ceiling in rats need further research.更多还原