葛根素对遗传性视网膜色素变性rd小鼠的干预作用及其抗凋亡机制研究

目的观察葛根素对视网膜色素变性rd小鼠外核层细胞和视网膜光感受器外段的病理、超微结构、凋亡和Bcl-2表达的影响,探讨葛根素对rd小鼠的干预作用和干预机制。方法rd新生小鼠随机分为2组,实验组和对照组。实验组小鼠从出生时腹腔注射葛根素80mg.kg-1,每天2次,至生后35d,对照组同时注射等量生理盐水。分别在用药后当日和3、7、14、21、28、35d取眼球,固定后,常规病理和电镜观察。用TUNEL方法检测视网膜光感受器细胞的凋亡,用免疫组化方法测定Bcl-2在视网膜的表达。结果病理结果显示,经葛根素治疗后14、21、28、35d,rd小鼠光感受器细胞层数与未用药的对照组相比较明显增加,P<0.01。电镜结果显示,葛根素可减缓rd小鼠光感受器细胞及其外段盘膜部位线粒体的病变,减少盘膜和外界膜的破坏。rd小鼠经葛根素药物治疗后d7、14、21、28、35,光感受器细胞的凋亡率比未用药的对照组明显减少,P<0.01;d3、7、14、21、28、35,Bcl-2在视网膜外核层及光感受器细胞外段的表达明显增强,P<0.05或P<0.01。结论葛根素可延缓rd小鼠视网膜外核层细胞和视网膜光感受器外段损伤。

Interventional effect and anti-apoptosis mechanism of the puerarin on the rd mice

Aim To observe the interventional effect and interventional mechanism of puerarin on retinal outer nuclear layer cell and photoreceptor outer segment in rd mice. Methods The rd mice were randomly divided into 2 groups, experimental group and control group. Between from postnatal 0 to 35 day, puerarin was injected by intraperitoneal twice a day. At different time postnatal 0, 3, 7, 14, 21, 28, 35 d, mice were sacrificed. Eyeballs were immediately enucleated and fixed. Routine pathological examination and electron-microscopic examination were done. The apoptosis of the outer nuclear layer cell apoptosis was detected by TUNEL technigue and the immunohistochemistry method was used to detect Bcl-2 expression in the retina. Results Results from light microscopy showed that the layer number of retinal outer nuclear layer with puerarin therapy was increased in 14, 21, 28, 35 d in rd mice, compared with control group. Results from electron-microscope showed that puerarin could reduce lesions occurrence in the photoreceptor cells and the destruction in disc member, mitochondrion,and outer limiting membrane in the photoreceptor outer segment were decreased in rd mice by the comparison with control group. Compared with control group, apoptotic cell numbers of the apoptotic outer nuclear layer cells were obviously reduced after 7,14,21,28 d and 35 d, and the Bcl-2 expression in the matrix of retinal photoreceptors and photoreceptor outer segments were obviously increased after 3, 7,14,21,28 d and 35 d in experimental group in rd mice. Conclusions Puerarin could postpone lesion occurrence of retinal outer nuclear layer cell and photoreceptor outer segment.