模拟失重大鼠心肌与血管组织的热应激诱导HSP70表达

刘春　 张立藩　 余志斌　 倪鹤鹦　

摘　要：为研究模拟失重是否可引起大鼠心肌与血管组织HSP70的诱导表达发生改变,用尾部悬吊大鼠模型模拟失重,以研究失重对生理的影响。用Northern杂交与Western印迹分析检测4周模拟失重大鼠热应激后并在室温下恢复1h(SUS-H₁)或2h(SUS-H₂)心肌、血管组织HSP70表达的变化。结果表明,热应激后,各组大鼠心肌组织的HSP72mRNA表达均显著增加,但SUS-H₂大鼠心肌组织的表达显著低于CON-H₂组;各组大鼠心肌组织HSP72表达也均显著增加,但SUS-H₁与SUS-H₂大鼠的表达与相应对照组相比,则仅呈降低趋势。基底动脉血管组织的HSP72mRNA与HSP72诱导表达均显著增高;而在股动脉则两者仅呈降低趋势。上述结果提示:模拟失重可导致大鼠心肌发生类似衰老的心肌改变;身体前、后部血管组织HSP70的诱导表达变化可能与血管的分化性适应方向一致。
关键词：模拟失重;热休克蛋白;Northern杂交;Western印迹分析;心肌;动脉
分类号：Q494; R852.22　文献标识码：A

Heat stress-induced HSP70 expression in heart and vessels of simulated weightless rats

LIU Chun（Department of Aerospace Physiology, the Fourth Military Medical University, Xi′an 710032）　
ZHANG Li-Fan（Department of Aerospace Physiology, the Fourth Military Medical University, Xi′an 710032）　
YU Zhi-Bin（Department of Aerospace Physiology, the Fourth Military Medical University, Xi′an 710032）　
NI He-Ying（Department of Aerospace Physiology, the Fourth Military Medical University, Xi′an 710032）　

Abstract：To examine the effect of simulated weightlessness on inducible HSP70 expression in the heart and vessel tissues of rats, a tail-suspension rat model was used to simulate weightlessness. HSP72 mRNA and HSP70 expression in heart and vessel tissues of both simulated weightless and control rats exposed to heat stress (ambient temperature, Ta=43℃) and recovered at Ta of 25℃ for 1 h (CON-H₁, SUS-H₁) or 2 h (CON-H₂, SUS-H₂) were analyzed using Northern blot and Western blot. The expression of HSP72 mRNA in the myocardium significantly decreased in SUS-H₂, as compared with that of CON-H₂ rats. The amount of HSP72 in the myocardium tended to decrease in both SUS-H₁ and SUS-H₂ groups, as compared with the corresponding control groups, but the differences were not statistically significant. The levels of inducible HSP70 expression in the vessels were related with their anatomical locations, for that the expression of both HSP72 mRNA and HSP72 significantly increased in basilar arteries, whereas it showed a slight decline in femoral arteries. The blunted HSP70 expression in myocardium suggests that simulated weightlessness may induce myocardial changes similar to those in aging. However, the HSP70 expression changes in arteries are in accord with the trend of differential adaptation changes in vessels to simulated weightlessness.
Keywords：simulated weightlessness; heat shock protein; Northern blot; Western blot; myocardium; artery

基金项目：This work was supported by the National Natural Science Foundation of China (No.39670800) and the Defence Medical Fund (98Z083).
作者单位：刘春（第四军医大学航空航天生理学教研室, 西安 710032）　
　　　　　张立藩（第四军医大学航空航天生理学教研室, 西安 710032）　
　　　　　余志斌（第四军医大学航空航天生理学教研室, 西安 710032）　
　　　　　倪鹤鹦（第四军医大学航空航天生理学教研室, 西安 710032）　

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收稿日期：2000年8月3日

修稿日期：2000年11月16日