Expression of vascular endothelial growth factor and injury of retinal cells in early diabetic retinopathy by electromicroscope / 西安交通大学学报(医学版)

ABSTRACT

Objective To study the effects of vascular endothelial growth factor(VEGF) in early stage diabetic retinopathy and their mechanisms,so as to guide the clinical work theoretically.Methods Thirty-six SD rats were randomly divided into four groups.Nine rats were used as normal controls(M Group).Streptozocin were injected intraperitoneally to induce diabetes for 1 month(M1 Group),2 months(M2 Group),and 3 months(M3 group).At the experimental ends of each group,the rats were over anesthetized and their eyeballs were extracted to make digest preparation.Immunofluorescence were used to investigate the expression of VEGF on retinal blood vessels.Transmission electromicroscopy was used to observe the histology of the retinal vessels.Results VEGF immunofluorescence showed an expression rate of 56% in M2 group and 89% in M3 group.Transmission electromicroscopy showed no change in M Group.However,it showed swelling of endothelial cells,finger like process into the capillary cavity,uneven distribution of heterochromatin in pericytes in M1 Group.Obvious fragmental thickening and splitting of basement membrane,swelling and deformation,finger like process to the capillary cavity,and concentration and margination of heterochromatin in endothelial cells,and swelling and deformation of rough surfaced endoplasmic reticulum and mitochondrion in pericytes were observed in M2 and M3 groups,especially in the latter.Conclusion The expression of VEGF proteins in the retinas of diabetic rats increases with the progression of diabetes.It proves that VEGF plays an important role in the occurrence and development of early diabetic retinopathy.