Application Of Perfusion Fluid In The Pathogenesis And Surgical Treatment Of Diabetic Retinopathy

[Objective] To investigate the expression of Fas, FasL and caspase-8 in the retina of diabetic rats and the effects of aminoguanidine . To study the pathogenesis of diabetic retinopathy and the therapeutical effect of ami noguani dine in early diabetic retinopathy . [ Method ] 24 Wister rats were randomly divided into diabetic mel 1 i tus (DM) group and aminoguanidine (AG) group . Six rats were used as control. Diabetes was induced in male rats by the intraperitoneal injection of streptozotocin (STZ) at a dose of 60 mg/kg . Age-matched control rats received buffer alone. Diabetes was characterized by an increase in blood glucose (>16.65 mmol/1) at 24 ~ 48 hour. The animals of aminoguanidine group receive aminoguanidine at a dose of 1 g/1 in drinking water . Diabetes and aminoguanidine groups are subdivided into 1DM, 3DM, 6DM, 1AG, 3AG, 6AG groups according to the course of disease. The expression of Fas, FasL and caspase-8 was studied by strept avidin-biotin complex (SABC) immunohistochemistry. [ Result] No Fas positive cells were observed in the normal retina. Positive expression of Fas gradually increased in 3DM group and 6DM group . In 3 DM group, positive expression of Fas was found in vascular endothelial cells , pericytes and ganglion cell layer. In 6 DM group , positive expression of Fas increase and extend to inner nuclear layer, outer nuc'ir layer and pigment epithelium layer. The positive expression of FasL is low in the normal retina. No caspase-8 positive cells were observed in the normal retina . In 3DM group , the expression of FasL and caspase-8 increase in endothelial cells, pericytes and ganglion cell layer of retina. In 6 DM group , positive expression of FasL and caspase-8 increase and extend to inner nuclear layer , outer nuclear layer and pigment epithelium layer. Aminoguanidine ameliorated the apoptosis in retinal tissue. In SAG and 6AG groups, the expression of Fas, FasL and caspase-8 were reduced in comparison with 3DM and 6DM groups (P<0. 05) . [ Conclusion ] Diabetes elevated the expression of Fas and FasL in the retina. Diabetes elevated the expression of caspase-8 in theretina . Fas, FasL and caspase-8 may have a role in the early events of the diabetic retinal apoptotic pathway. Aminoguanidine may cure diabetic retinopathy through its inhibition on the expression of Fas, FasL and caspase-8 in early diabetic retinopathy.