诱导型热休克蛋白70在大鼠视网膜的表达及其对视网膜缺血再灌注损伤的保护作用

目的　检测锌离子诱导的HSP70 在大鼠视网膜的表达及HSP70 对视网膜缺血再灌注损伤的保护作用。方法　生理盐水前房加压灌注制作视网膜缺血再灌注 (RIR)损伤模型 ,腹腔注射硫酸锌诱导HSP70 表达 ,作为实验组 ;腹腔注射HSP表达抑制剂 -Quercetin(槲皮素 ) ,为实验对照组 ;另取大鼠不行任何处理作正常对照组。不同时间段作视网膜HSP70 免疫组化染色 ,视网膜病理 (HE)染色、神经节细胞 (RGCs)计数 ,视网膜透射电镜观察 ,比较各组差异。结果　实验组在注射硫酸锌后 10h即见视网膜节细胞层有HSP70 阳性表达 ,16h达高峰 ,7d后仍呈弱阳性表达 ,HSP70 主要在RGCs胞浆表达 ;正常对照组及实验对照组均呈阴性表达。RIR后实验组和实验对照组均有RGCs损失 ,其中RIR后 2 4h ,实验组RGCs计数多于实验对照组且有统计学意义 (P <0 .0 5 ) ,RIR后 3d、7d差异有显著性 (P <0 .0 1) ;透射电镜观察显示实验组损伤轻于实验对照组。结论　腹腔注射锌离子可诱导大鼠视网膜的HSP70 表达 ,腹腔注射槲皮素可抑制此作用 ,HSP70 主要在RGCs胞浆表达 ;HSP70 能提高RGCs对RIR损伤的耐受性

Expression of HSP70 Induced by Zinc in Rat Retina and its Protective Abilityin Retina Ischemic Reperfusion Injury

Objective To examine the expression of HSP 70 induced by zinc in rat retina and its protective ability in retina ischemic-reperfusion(RIR) injury.Methods Retina ischemic-reperfusion was induced in rat by acute elevated intraocular pressure through normal saline intracameral perfusion.The HSP 70 was induced by zinc sulfate intraperitoneal injection,the rats in control group were injected with zinc sulfate and HSP expression inhibitor-Quercetin(Q).The expression of HSP 70 was observed by immuno-histochemistry method.In different time after RIR,the histological and ultrastructural changes were observed.The number of retinal ganglion cells (RGCs) was counted and compared in different groups.Results The positive stain of HSP 70 in rat retinas of group Zn was observed at the 10th hour after being injected with zinc,and reached the peak at the 16th hour;until the 7th day,weak positive stain could still be observed.HSP 70 expressed mostly in cytoplasm of RGC.In normal control group and group Q+Zn,the stain of HSP 70 was negative.The number of RGCs decreased after RIR in both group Q+Zn+RIR and group Zn+RIR.The number of RGCs in group Zn+RIR is significantly more than that in group Q+Zn+RIR at the 24th hour post RIR(P<0.05),and much significantly at the 3rd day and the 7th day post RIR(P<0.01).The retina ultrastructural injury in group Zn+RIR was slighter than that in group Q+Zn+RIR.Conclusion Zinc injected intraperitoneally can induce the expression of HSP 70 in rat retina and quercetin can inhibit the expression.HSP 70 express mostly in cytoplasm of RGC.HSP 70 protect RGCs against RIR injury.