中文摘要：

目的：检测半胱氨酸蛋白酶3mRNA在光感受器凋亡大鼠视网膜中的表达，探讨其在光感受器细胞凋亡的发生、发展中的意义。方法：实验于2004—03／12在中山眼科中心眼科学教育部重点实验室完成。选择雌性SD大鼠36只，随机数字表法分为正常对照组6只，N-甲基-N-亚硝脲组30只，后者又分为造模后12h，1，2，3，5d5个时相点．每个时相点6只。正常对照组大鼠经腹腔注射生理盐水；N-甲基-N-亚硝脲组大鼠按体质量一次性腹腔注射N-甲基-N-亚硝脲40mg／kg，分别于造模后12h，1，2，3，5d处死动物，摘除右眼球，立即分离视网膜，提取总RNA，用荧光定量聚合酶链反应法检测视网膜中半胱氨酸蛋白酶3mRNA的含量。结果：纳入动物36只，均进入结果分析。正常对照组、N-甲基-N-亚硝脲组造模后12h，1，2，3，5d5个时相点视网膜中半胱氨酸蛋白酶3mRNA表达量分别为1．52×10^5，18．35×10^5，25．14×10^5，29．25×10^5，13．72×10^5．12．24×10^5。N-甲基-N-亚硝脲腹腔注射后12h视网膜中半胱氨酸蛋白酶3mRNA表达量上升，第2天时最高，达正常对照组表达量的19倍，此后渐下降，第5天表达量仍为正常对照组的8倍。结论：视网膜中半胱氨酸蛋白酶3mRNA表达与光感受器细胞的存亡有关，可作为光感受器细胞凋亡发生、发展的预测指标之一。

英文摘要：

AIM： To detect the expression of caspase-3 mRNA in rats with apoptosis of retinal photoreceptor cells, and investigate the significance of caspase-3 in the occurrence and progress of apoptosis of.photoreceptor cells. METHODS： The experiment was conducted at Zhongshan Ophthalmic Center, Key Laboratory of Ophthalmology by State Ministry of Education from March to December in 2004. Thirty-six female SD rats were selected and stochastically divided into normal control group （n=6） and N-methyl-Nnitrosourea （MNU） group （n=30）. And MNU group was arranged into 5 subgroups based on scheduled times of 12 hours and 1, 2, 3 and 5 days after model establishment, 6 rats for each. Normal saline was injected intraperitoneally to each rat of normal control group, whereas 40 mg/kg MNU was given intraperitoneally to the rest rats according to body mass. At the scheduled time points after model establishment, the rats were sacrificed for enucleating right eyeballs, isolating retina immediately and extracting total RNA. The expression of caspase-3 mRNA was examined by real-time fluorescent quantitative polymerase chain reaction in rat retinas. RESULTS： All 36 rats were involved in the result analysis. The expressions of caspase-3 mRNA in the rat retinas of both groups at scheduled time points of 12 hours and 1, 2, 3 and 5 days after model establishment were 1.52×10^5, 18.35×10^5, 25.14×10^5, 29.25×10^5, 13.72×10^5 and 12.24×10^5 respectively. The expression of caspase-3 mRNA in MNU groups elevated after 12 hours of intraperitoneal injection, and rose to the top at the 24 day, which was 19 times as many as that of normal control. Then it began to decline, and was still 8 times to that of normal control at the fifth day. CONCLUSION： The expression of caspase-3 mRNA is related to apoptosis of photoroceptor cells. Caspase-3 mRNA may be a valuable marker for the occurrence and progress of apoptosis of photoreceptor cells.