亚低温对大鼠局灶性脑缺血后HSP70 mRNA表达影响

①目的观察亚低温对大鼠局灶性脑缺血后热休克蛋白70(HSP70)mRNA表达的影响。②方法取成年健康Wistar大鼠145只,应用线栓法建立大脑中动脉闭塞(MCAO)再灌注模型,随机分为健康对照组、假手术组、缺血再灌注对照组(H0)、缺血后即刻亚低温组(H1)、缺血再灌注后亚低温组(H2)。采用原位杂交方法检测各组脑组织HSP70mRNA表达。③结果H0组HSP70mRNA表达于缺血再灌注2h出现,24h明显,48h减少,72h降到最低。H1和H2组HSP70mRNA阳性表达6~48h明显,72h、7d额叶皮质仍有HSP70mRNA表达,较H0组表达增多,差异有显著性(F=96.72~716.59,q=11.95~124.73,P<0.001)。H1组与H2组比较,前者HSP70mRNA表达更为明显,差异有显著性(q=7.56~60.49,P<0.001)。④结论亚低温治疗后脑组织HSP70mRNA表达增多,缺血后即刻亚低温的作用优于缺血再灌注后。

INFLUENCE OF MODERATE HYPOTHERMIA ON EXPRESSION OF HSP70 mRNA FOLLOWING FOCAL ISCHEMIA IN RATS

Objective To observe the effects of moderate hypothermia on the expression of HSP70 mRNA in focal model of transient cerebral ischemia in rats. Methods One hundred and forty-five adult rats were randomly divided into five groups: normal control group, sham-operated group, ischemia reperfusion group(H0), ischemia hypothermia group(H1), and ischemia reperfusion hypothermia (H2) group. Koizumi's ischemia/reperfusion model was used. The expression of HSP70 was measured by in situ hybridization. Results In H0 group, the expression of HSP70 emerged at 2 h after reperfusion and peaked at 24 h. In H1 and H2 groups, the positive expression of HSP70 increased significantly during 6-48 h, especially in the cortex of the frontal lobe at 3 d and 7 d, the difference was significant as compared with H0 (F=96.72-716.59, q=11.95-124.73,P<0.001). The expression of HSP70 mRNA in H1 was more obvious than in H2 (q=7.56-60.49, P<0.001). Conclusion The expression of HSP70 is increased by hypothermia, immediate hypothermia after ischemia is superior to reperfusion.