金纳多对RCS鼠视网膜色素变性神经元保护作用

THE PROTECTIVE EFFECTS OF GINATON(EGb761) ON HEREDITARY RETINAL DYSTROPHY IN RCS RATS

目的 探讨金纳多（Ginaton，EGb761）对RCS大鼠视网膜色素变性神经元保护作用的机制。方法 将出生后雄性RCS大鼠48只随机分为给药组和对照组。给药组大鼠从生后7d开始腹腔注射金纳多，每3d注射一次，剂量为100mg／kg。对照组大鼠注射生理盐水，剂量相同。苏木精-伊红染色和TUNEL检测观察EGB761对视网膜色素变性神经元的保护作用。应用免疫组织化学方法检测Caspase-2蛋白的表达。结果 给药组大鼠生后20和25d，感光细胞的数目与对照组大鼠比较明显增加（t=3．32、3．56，P〈0．05）。给药组大鼠生后25d TUNEL检测阳性细胞数目比对照组少，差异有统计学意义（t=3．74，P〈0．05）。生后25～40d，给药组和对照组大鼠在节细胞层和内核层观察到Caspase-2阳性染色。给药组大鼠生后20和25d时内核层Caspase-2阳性细胞数少于对照组（t=2．87，P〈0．05）。结论 在RCS大鼠视网膜变性的早期，EGb761对神经元起保护作用，其作用机制可能与Caspase-2蛋白的低表达有关。

Objective To explore the protective mechanisms of Ginaton （EGb761） on hereditary retinal dystrophy in RCS rats. Methods A total of 48 male RCS rats were randomly divided into treated and control groups. EGb761 100 mg/kg was injected intra-peritoneally, once every three days in treated group, starting from seven days after birth; saline was given to the controls, dose and medication being the same as the treated group. The protective effect of EGb761 against retinal dystrophy was assessed by HE staining and TUNEL. The expression of Caspase-2 was detected by immunohistochemistry. Results The number of photoreceptor in the treated group was more than that in the controls at 20 and 25 days after birth （t=3.32,3.56;P〈0. 05）. Twenty-five days after birth, the number of TUNEL-positive cells of the treated group was obviously less than that of the controls （t=3.74,P〈0.05）. From 25 to 40 days after birth, the Caspase-2-positive cells were seen in the ganglion cell layer and inner nuclear layer in both treated and control groups. The number of positive cells in the inner nuclear layer of treated group was less than that of the control group （t= 2.87, P〈0.05）. Conclusion EGb761 has a protective effect on the early stage of retinal degeneration of RCS rats, its mechanisms may be related to the low expression of Caspase-2.