AIM:To observe the protective effect of pigment epithelium derived factor(PEDF)on retinal ganglion cells(RGCs)after acute injury of optic nerve in rats.

METHODS: Totally 60 healthy female SD rats were randomly divided into three groups: blank group, model group and experimental group, 20 rats in each group. Acute injury model of optic nerve in rats are established by crushing optic nerve. After the model of optic nerve injury was made successfully in model group, the rats were injected with balanced salt solution 5μL into vitreous cavity, and at 1 and 2wk later respectively they were injected again. In experimental group, after the model of optic nerve injury was made successfully, immediately the rats were injected with the PEDF 5μL into vitreous cavity, also at 1 and 2wk later respectively they were injected again. To observe the retinal morphologic changes and count the number of retinal ganglion cells, the specimen was given HE staining and observed under light microscope. The immunohistochemical semi quantitative method was used to detect the expression of Bcl-2 and Bax to observe the effect of PEDF on the optic nerve after injury.

RESULTS: Cell morphology of ganglion cells in experimental group was better and the number of RGCs was much more, comparing with the model group by HE staining. The expression of Bcl-2 and Bax in the experimental group was significantly different with that in the blank group and the model group(P<0.05). The expression of Bcl-2 increased and the expression of Bax decreases in the experimental group compared with the model group.

CONCLUSION: PEDF can inhibit or weak the apoptosis of RGCs cells after optic nerve injury and alleviate the injury of optic nerve by increasing the expression of Bcl-2 protein or decreasing the expression of Bax protein.