【摘要】 目的观察银杏叶提取物(EGB)对糖尿病大鼠视网膜神经节细胞凋亡的影响,探讨EGB防治糖尿病性视网膜病变的作用机制。方法选择健康成年W istar大鼠50只,随机分成正常对照组、模型组、低剂量EGB组、中剂量EGB组、高剂量EGB组。腹腔内注射链脲佐菌素(STZ)诱发大鼠糖尿病。低、中和高剂量EGB组分别给予EGB溶液50,100和200 mg.kg-1.d-1,灌胃给药,模型组和正常组均灌胃等体积0.9%氯化钠溶液,均连续12周。制备大鼠视网膜石蜡切片行末端脱氧核苷酸转移酶介导的dUTP缺口末端标记(TUNEL)法,检测视网膜神经节细胞凋亡指数(AI),并对染色结果行计算机图像分析。电镜观察各组神经节细胞的超微结构变化。结果模型组大鼠神经节细胞AI比正常对照组显著增加(P<0.01),中、高剂量EGB组神经节细胞AI与模型组比较明显减少(P<0.01),低剂量EGB组神经节细胞AI与模型组比较差异无显著性(P>0.05)。中、高剂量EGB组神经节细胞超微结构的损害明显减轻。结论EGB可以通过抑制视网膜神经节细胞的凋亡来减轻糖尿病性视网膜病变。更多还原

【Abstract】 Objective To survey the effect of the extract of ginkgo biloba leaves(EGB)on the apoptosis of retinal ganglion cells in diabetic rats and to approach the mechanisms underlying the effect of the drug in the prevention and treatment of diabetic retinopathy. Methods 50 healthy adult male Wistar rats were randomly divided into 5 equal groups: ①control group,②model group,③low-dose EGB treatment group,④ medium-dose EGB treatment group and ⑤ high-dose EGB treatment group.A model of experimental diabetes was formed in each of the rats of group ② to group ⑤ by a single intraperitoneal injection of streptozotocin(STZ).RATS of group ③,④ and ⑤ were given each 50,100 and 200 mg·kg-1 EGB administered by gastrogavage q.d.respectively,for 12 consecutive weeks.Animals of group ① and group ② were given each an equivalent amount of 0.9% sodium chloride solution q.d.by the same route for 12 weeks as well.Paraffin sections of the retina were prepared and the apoptosis indexes(AI) of the ganglion cells determined with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling(TUNEL)method and the results were analyzed in a computer-picture system.Ultrastructural changes in the ganglion cells were examined under the electron microscope. Results The AI of the ganglion cells in rats of group ②(the model group) was apparently higher than that in rats of group①(the control group)(P<0.01).The ganglion cell AIs in rats of group ④(treated with medium-dose EGB) and group ⑤(treated with high-dose EGB) were significantly lower than that in rats of group②(P<0.01).However,the difference between the ganglion cell AI in rats of group ③(treated with low-dose EGB) and that in rats of group ② was insignificant(P>0.05).Lesions in the ultrastructure of the retinal ganglion cells in rats of group ④ and group ⑤ were trifling as compared with those in rats of group ②. Conclusion EGB was shown to exert its curative effect in the treatment of diabetic retinopathy possibly by inhibiting apoptosis of the retinal ganglion cells.更多还原