摘要
目的 通过低 G重复暴露的预适应作用 ,来诱导热休克蛋白 70 (HSP70 )表达 ,以探讨预刺激的适宜强度。 方法 SD大鼠 80只 ,随机分为正常对照组 (5只 )和 +4 Gz重复暴露 (+4 Gz/3min,3次 / d) 1d、3d和 5 d组 (每组 2 5只 ) ,分别于暴露后 6 h、1d、2 d、4d和 6 d处死取脑 ,做冰冻切片 ,进行免疫组织化学染色 ,观察 HSP70的表达水平。 结果 各实验组 +4 Gz/ 3m in重复暴露后HSP70在皮层、海马、丘脑和丘脑下部等部位的表达均有明显的时相特点。暴露后 6 h各部位均有轻中度的 HSP70阳性反应 ,暴露后 1d表达至峰值 ,2～ 3d后开始明显减弱。从表达部位看 ,HSP70阳性反应在顶叶皮层、梨状皮层和丘脑下部表达较强 ,丘脑次之 ,海马较弱。各组 HSP70表达峰值虽均在暴露后 1d,但暴露 1d组 2 d后强度明显减弱 ,而暴露 3～ 5 d组在 2 d后仍然维持较高水平 ,即除海马外 ,各脑区在暴露后第 6天仍有较高的表达 ,均未恢复至正常对照水平。 结论 多天低 G重复暴露诱导的 HSP70表达较 1d重复暴露组的表达更强 。
Objective To explore the suitable intensity of repeated low +G z adaptation exposure in order to induce the highest heat shock protein 70(HSP70) expression in rat brain. Methods Eighty SD male rats were randomly divided into control group (5 rats), +4 G z exposures (+4 G z/3 min,3 times/day) one day, three days and five days group (each group 25 rats). The expression levels of HSP70 in rat brain were measured by immunohistochemistry staining 6 hours, 1 day, 2 days, 4 days, 6 days after last exposure. Results The HSP70 expression levels after repeated +4 G z exposures had obvious phasic characteristics in cortex, hippocampus, thalamus and hypothalamus. The expression level of HSP70 6 hours after exposure was weak, it reached peak value 1 day after exposure, and began lowering down 2 or 3 days after the exposures. The expression level of HSP70 was strongest in parietal cortex, piriform cortex and hypothalamus, strong in thalamus, and relatively weak in hippocampus. In all 3 experimental groups, the HSP70 expression reached peak value 1 day after last exposure, but it was obviously weakened 2 days after exposures in 1 day group, while in 3 days and 5 days group it maintained on a high level and it did not return to normal value 6 days after last exposure. Conclusion The results indicated that the level of HSP70 expression after repeated +4 G z exposures for several days were stronger, and its sustaining time was longer than those of single day exposure group.
出处
《中华航空航天医学杂志》
CSCD
2002年第3期152-155,共4页
Chinese Journal of Aerospace Medicine
基金
国家自然科学基金资助项目 ( 3980 0 15 8)
