糖视明胶囊对糖尿病大鼠视网膜神经细胞凋亡及bcl-2、bax、caspase-3表达的影响

Effects of tangshiming on apoptosis of retinal ganglion cell and expression of bcl-2,bax and caspase-3 in rat with diabetic retinopathy

目的研究糖视明胶囊对糖尿病视网膜病变(DR)神经细胞凋亡的影响。方法将雄性SD大鼠随机分为阴性对照组、模型对照组、糖视明组,采用链脲佐菌素腹腔注射的方法制作大鼠DR模型,末端脱氧核糖核酸介导生物素化脱氧尿嘧啶缺口末端标记法(TUNEL)标记大鼠视网膜凋亡细胞,免疫组织化学SABC法测定bcl-2、bax以及caspase-3的基因表达。结果与阴性对照组比较,模型对照组大鼠视网膜神经细胞凋亡数、caspase-3和bax阳性细胞数显著增加,bcl-2/bax明显下降,糖视明组能明显降低视网膜神经细胞凋亡数、caspase-3和bax阳性细胞数,提高bcl-2阳性细胞数与bcl-2/bax的比值,与模型对照组比较差异有统计学意义。结论糖视明可通过对caspase和bcl-2两大家族的调节抑制细胞凋亡,从而减轻早期DR的程度。

Objective To study the effect of the tangshiming on neuron apoptosis with diabetic retinopathy（DR） in rats. Methods Thirty male SD rats were randomly divided into negative control group,model control group and tangshiming treated group and 10 for each. Diabetes model was established by intraperitoneal injection of 60 mg/kg streptozotocin（STZ）. 0. 5 g/kg tangshiming was given by gastrogavage 4 times per day for 60 consecutive days in the rats of tangshiming treated group, and an equivalent amount of 0.5% CMC-Na was utilized at a same way in the animals of negative control group and model control group. Terminal Deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling（ TUNEL staining） was used to observe neuron apoptosis in retina. The protein expressions of caspase-3, bcl-2 and bax in retina were detected by immunohistochemistry method. Result TUNEL positive cells and caspase-3, bcl-2 and bax immunoreactive neurons in retina and ratio of bcl-2/bax were evidently different among different groups （ F = 171.92,5.91,8.57,110. 15,27.83,respectively,P 〈 0. 01 ）. Compared with the control group, TUNEL positive cells, caspase-3, and bax immunoreactive neurons in retina were increased significantly （ P 〈 0.01 ） , but the ratio of bel-2/bax was obviously decreased （P 〈0.01 ） in model control group. No considerable change was found in bcl-2 level between negative and model control groups （ P 〉 0.05 ）. However, TUNEL positive cells and caspase-3, bcl-2 and bax immunoreactive neurons in retina in tangshiming treated group were significantly decreased and the ratio of bcl-2/bax was significantly increased in comparison with model control group （ P 〈 0.05 - 0. 01 ）. Conclusion The therapeutic effects of tangshiming on diabetic retinopathy can be realized by inhibiting apoptosis.