中文摘要：

背景：视网膜色素变性是非炎症性、双侧进行性的视网膜变性，其特征是光感受器细胞因发生凋亡而丢失，最终导致失明。中药黄芪在阻止该病的进程上显示出了良好的前景。 目的：观察黄芪对N-甲基-N-亚硝脲致SD大鼠视网膜损伤的保护作用。 设计：随机对照动物实验。 单位：新乡医学院药学院。 材料：实验于2004—03／12在中山大学中山眼科中心药理实验室完成。雌性SD大鼠114只，由中山大学中山医学院动物中心提供，N-甲基-N-亚硝脲为美国Sigma公司产品，黄芪注射液为成都地奥九泓制药厂生产（生产批号：国药准字Z99060535，2mL／支，主要成分为黄芪）。 方法：选用雌性SD大鼠114只，30只用于视网膜层形态学分析；30只用于细胞凋亡检测；54只用于胞核内核因子κBp65活性的检测。采用抽签法随机分组，每组6只。于大鼠生后47d，分别经腹腔注射不同剂量的黄芪（2．5．5和10g／kg），1次／d，除对照组外，其余组的大鼠同时于生后50d腹腔注射N-甲基-N-亚硝脲60mg／kg。在N-甲基-N-亚硝脲处理不同时间后处死动物，取眼球，视网膜形态学分析测量周边视网膜的总厚度，TUNEL试剂盒检测光感受器细胞凋亡，转录因子试剂盒分析核因子κBp65的活性。 主要观察指标：各组视网膜厚度、凋亡指数和胞核内核因子κBp65的活性比较。结果：黄芪可剂量依赖性地显著增加周边视网膜总厚度和降低N-甲基-N-亚硝脲引起的光感受器细胞凋亡指数。黄芪注射液10g／kg还可时间依赖性地上调视网膜细胞胞核内核因子κBp65的活性。但其对N-甲基-N-亚硝脲引起的中心视网膜损伤无明显的保护作用。 结论：黄芪通过上调视网膜细胞胞核内核因子KBp65的活性，抑制光感受器细胞凋亡，从而部分地保护N-甲基-N-亚硝脲引起的视网膜损伤。

英文摘要：

BACKGROUND： Retinitis pigmentosa （RP） is a non-inflammatory, bilaterally progressive, retinal degeneration characterized by loss of photoreceptor cells via an apoptotic mechanism, and it eventually leads to blindness. Research shows that the traditional Chinese medicines of Astragalus has great prospect on blocking the progression of RP disease. OBJECTIVE： To observe the protective effect of Astragalus on N-methyl-N-nitrosourea （MNU）-induced retinal damage in Sprague-Dawley （SD） rats and provide the optimal treatment for RP in humans. DESIGN： Randomized controlled experiment. SETTING： School of Pharmaceutical Sciences, Xinxiang Medical College. MATERIALS ：The experiment was completed in Pharmacological Laboratory of Zhongshan Ophthalmic Centre, Sun Yat-sen University between March to December 2004. Totally 114 female SD rats were purchased from the Animal Center of Zhongshan Medical College, Sun Yat-sen University. MNU was purchased from Sigma Company of America. Astragalus inje.ction was purchased from Chengdu Diao Jiuhong Pharmaceutical Factory （Batch No. Z99060535, 2 mL/ampoule, main ingredient： Astragalus）. METHODS： Among 114 rats, 30 were for morphometric analysis of retinal layers, 30 were for detection of apoptosis and 54 were for detection of NFKB p65 activity. All of them were randomly divided into different groups and each group had 6 rats. Astragalus at doses of 2.5, 5 and 10 g/kg were injected intraperitoneally into 47-day rats once a day. Meanwhile, a single intraperitoneal injection of 60 mg/kg MNU was given to 50-day rats in model and Astragalus groups. At different intervals after MNU treatment, the animals were sacrificed. Retinal damage was evaluated based on retinal thickness, the apoptotic index of the photoreceptor cells was detected by TUNEL labeling and the DNA-binding activity of NF-κB p65 was analyzed according to transcription factor assay kit. MAIN OUTCOME MEASURES： Comparison of retinal thickness, apoptotic index and the activity of nuclear NF