银杏苦内酯B对N-甲基-N-亚硝脲诱导的大鼠视网膜细胞凋亡的抑制作用  

Protective mechanisms of ginkgolide B on rat retinal cell apoptosis induced by N-methyl-N-nitrosourea

作　　者：孟晶[1] 张旭[1] 陈青山 张日佳[1] 丁小燕[3] 

机构地区：[1]暨南大学附属第一医院眼科 [2]医学院流行病学教研室,广东广州510632 [3]中山大学中山眼科中心,广东广州510060

出　　处：《中国病理生理杂志》2012年第4期694-699,共6页Chinese Journal of Pathophysiology

基　　金：广东省医学科研基金资助项目(No.B2009125);建设中医药强省科研课题(No.2010363);广东省科技计划项目(No.2011B031700045)

摘　　要：目的:探讨银杏苦内酯B(GB)对N-甲基-N-亚硝脲(MNU)诱导的大鼠视网膜变性的影响及其机制。方法:建立大鼠视网膜变性模型,应用TUNEL法检测光感受器细胞凋亡,RT-PCR法和免疫组织化学法分别检测MNU作用后不同时间大鼠视网膜中bcl-2和bax mRNA和蛋白的表达。结果:GB治疗组外核层细胞凋亡指数显著低于模型组(P<0.01)。MNU作用后12 h、1 d、2 d、3 d和5 d,bcl-2/bax mRNA模型组为0.36、0.15、0.29、0.42和0.64,GB治疗组为0.98、0.92、0.53、0.45和0.68,显著高于模型组(P<0.01)。GB治疗组Bcl-2蛋白在MNU给药后1 d表达最强,2 d阳性表达下降,3 d后阳性表达消失,模型组未见视网膜Bcl-2阳性表达;GB治疗组Bax蛋白表达显著低于模型组(P<0.01)。结论:银杏苦内酯B能抑制MNU诱导的视网膜光感受器细胞凋亡,可能与上调Bcl-2的表达量,提高Bcl-2/Bax比值有关。AIM： To investigate the protective mechanisms of ginkgolide B（GB） on rat retinal degeneration induced by N-methyl-N-nitrosourea（MNU）.METHODS： The rat retinal degeneration model was made.Photoreceptor cell apoptosis was measured by TUNEL assay.The expression of Bcl-2 and Bax in the different time points in the rat retina after treated with MNU was measured by RT-PCR and immunohistochemical methods.RESULTS： The outer nuclear layer cell apoptotic index in GB treatment group was significantly lower than that in model group（P0.01）.The bcl-2/bax mRNA ratios at scheduled time points of 12 h,1 d,2 d,3 d and 5 d after MNU injection in model control were 0.36,0.15,0.29,0.42 and 0.64,respectively,while the ratios in GB group were 0.98,0.92,0.53,0.45 and 0.68,respectively,larger than those in model control group（P0.01）.No Bcl-2 positive expression was detected at any scheduled time points after MNU injection in model control group.Strong positive Bcl-2 expression was detected in GB group 1 d after MNU injection,decreased at the 2nd day and disappeared at the 3rd day.Compared with model control group,the Bax expression in GB group was significantly decreased（P0.01）.CONCLUSION： Ginkgolide B effectively inhibits the apoptosis of photoreceptor cells.The mechanism of GB action may be related to the increase in the expression of Bcl-2 and the increase in the ratio of Bcl-2/Bax.

关 键 词：N-甲基-N-亚硝脲 银杏苦内酯B 视网膜 细胞凋亡 光感受器细胞 

分 类 号：R363[医药卫生—病理学]