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(P<0.01)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(P<0.01). Conclusion:Insulin can protect from the apoptosis of corneal alkali burn through increasing the expression of Bcl-2.