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。
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（△Tmax） 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.
出处
《第二军医大学学报》
CAS
CSCD
北大核心
2005年第8期881-884,共4页
Academic Journal of Second Military Medical University
基金
国家自然科学基金(30270198).
