胰岛素在兔角膜碱烧伤后抗凋亡作用的初步研究

Preliminary study about anti-apoptosis activity after application of the insulin in a rabbit model of corneal alkali burn

目的:研究胰岛素(Insulin,INS)对兔角膜碱烧伤后角膜组织细胞凋亡及Bcl-2表达的影响。方法:建立兔Ⅱ度角膜碱烧伤动物模型,球结膜下分别注射生理盐水(B组)和INS(C组),正常兔眼做对照(A组)。用药后不同时间点取材,应用光镜、电镜及细胞凋亡原位末端标记法(TUNEL)分别检测角膜组织凋亡细胞,免疫组化法观察Bc1-2蛋白的表达和变化。结果:正常角膜上皮细胞层仅有极少量凋亡细胞,基质层及内皮细胞层几乎无凋亡细胞,Bcl-2蛋白主要表达在上皮层,基质层及内皮层亦有少量表达。C组在第7、14d角膜TUNEL染色阳性细胞明显少于B组(P<0.01),Bcl-2蛋白表达明显多于B组(P<0.01)。结论:INS可能通过增加Bcl-2蛋白表达抑制碱烧伤角膜组织细胞凋亡。

Objective：Toexplore the effectofinsulin（INS） administration on the expression of Bcl-2 protein and the apoptosis of corneal histiocytes following rabbit model of corneal alkali burn.Methods：to establishⅡdegree rabbit model of corneal alkali burn,and respectively to inject normal saline（B group）,INS（C group）in the subconjunction each day,and the normal rabbit eyes as controls（A group）.The different time after operation the corneal samples were remove and fixed.the apoptosis of corneal histiocytes were detected by light microscope,electron microscope and transferase-mediated dUTP-digoxigenin nick and labeling assay（TUNEL）,the expression and alteration of Bcl-2 protein using immunohistochemisty.Results：The TUNEL positive cells were present slightly in the epithelium of normal comea and not present onstroma and endothelium.Bcl-2 were expressed mainly on the normal corneal epithelium,a lower number of Bcl-2 expression on stroma and endothelium.The TUNEL positive cells of group C was stgnificantly lower than that（P0.01）in group B,and the expression of Bcl-2 in group C was markedly increased on the 7th day and the 14th day in comparison with group B（P0.01）. Conclusion：Insulin can protect from the apoptosis of corneal alkali burn through increasing the expression of Bcl-2.