高眼压下大鼠视网膜HSP70表达与显微结构变化

目的 研究高眼压下大鼠视网膜热休克蛋白70(HSP70)的表达规律及其高眼压下视网膜电子显微镜下结构变化。方法 本实验分为2部分,第1部分将大鼠右眼制成高眼压模型,维持1h 110mmHg(1mmHg=0.133kPa)高眼压,按观察时间分为4组,每组6只大鼠,分别在4、18、24、48h后摘除眼球,同时每组均有4只大鼠作为对照只灌注,不加压,运用免疫组织化学方法,研究高眼压下大鼠视网膜HSP70的表达规律,第2部分分为免疫组和电镜组,其中免疫组中按高眼压维持时间不同,将动物分为3组,每组6只大鼠,高眼压维持时间分别为:0.5、1.5、2.5h,高眼压去除后,使其生存18h后,摘除眼球,每组也有4只大鼠只灌注不加压。电镜组中动物分组、高压眼作用时间、动物生存时间、对照组设计均与免疫组相一致,其中动物分组均随机分组。结果 高眼压后18h视网膜各层HSP70的表达有显著增高(P<0.01),到24h均有下降,但仍接近18h(细胞内层节段除外)。在本实验的高眼压范围内,电子显微结构变化提示;视网膜视细胞层对高眼压有较强的耐受性,HSP70在此范围高眼压下,视网膜各层内的表达随高眼压作用时间的延长无显著性差异(P>0.05)。结论 高眼压下大鼠视网膜各层HSP70的表达显著增高与视细胞的显微结构变化相一致。

HSP70 expression in rat retina in intraocular hypertension with the changes in ultra structure of retina

Aim To study the expression of heat shock protein 70 (HSP70) in rat retina with intraocular hypertension and its relation with retinal microscopic structure. Methods The research was conducted in 2 sections. In one section, 24 rats, on which intraocular hypertension had been induced in the right eyes, were divided into 4 groups (6 in each) and the eyeballs in each group were extracted respectively 4, 18, 24, 48h after induction of intraccular hypertensioa In each group, four rats were used as control, on which only perfusing was conducted at various times (0.5, 1.5, 2.5h) after induction of intraocular hypertension. In the other section, the rats were divided into immunochemical group and electron microscopy group. In the immunochemical group, the rats were divided into 3 groups (6 in each), with intraocular hypertension maintained for 0.5, 1.5, 2.5h respectively. Eyeball was extracted 18 hours after removal of intraocular hypertension. In the microscope group, the experiment design was the same. Results The HSP70 was expressed in every layer of normal rat retina. The greatest increase occurred at 18 hours after intraocular hypertension in all layers, with a particularly dramatic increase in the photoreceptor inner segments (P<0.01). By 24h, the expression of HSP 70 had decreased, but it was still close to that at 18h except in the inner segments. The photoreceptor cells appeared to be the retinal cells which exhibited a vigorous heat shock response. Conclusion The expression in all layers of rat retina with intraocular hypertension increases significantly, which is consistent with the changes in microscopic structure of photoreceptor cells.