The Effect Of VEGF On Formation Of Proliferative Diabetic Retinopathy And Expression Of Vitreous TGF-?₁ In Canine

Objective:(1)The impact of VEGF on PDR formation was explored by fundus fluorescein angiography and retinal vascular endothelial cells CD105 immunohistochemistry to detect incidence of 3 groups of canine proliferative diabetic retinopathy.(2)The relative expression of TGF-?1 m RNA in the Vitreous of the 3 groups of dogs was determined by the method of relative fluorescence quantitative PCR,and the effect of VEGF on the expression of TGF-?1.Methods:(1)The Chinese garden canine with the same physical health condition was selected,and the diabetes model was established,which were random Ly divided into S1 group and S2 group(n = 5)in each group.The vitreous cavity of group S1 was injected with VEGF(0.2ug/kg);The vitreous cavity of group S2 was injected with the same amount of saline;Random Ly selected 5 healthy dogs as group S3,the vitreous cavity of group S3 were injected with the same amount of saline,as a blank control group.(2)After vitreous cavity injection,the 3 groups of dogs were examined by fluorescein fundus angiography,and the leakage of blood vessels in the eyes of each group was observed and recorded for 8w.At the end of 8th week,the retina of the same position in the left eye of each group of dogs were collected,and the pathological sections were made for CD105 immunohistochemical staining,the immunohistochemical staining of each group was observed under microscope and recorded.(3)After intravitreal injection of 8w,the vitreous of the left eye of each group was collected for 2 m L,which was stored in the liquid nitrogen.The relative expression of TGF-?1m RNA in dogs in each group was measured by fluorescence quantitative PCR.(4)Finally,the data were analyzed by SPASS analysis software.Results:(1)Fundus fluorescein angiography showed that,one of the test dogs began to appear a slight leakage of blood vessels at the 5th week,fluorescein leakage occurred in all the dogs in group S1 at the 8th week.There was no fluorescent leakage of blood vessels in the group S2 and group S3 in the 8 weeks.(2)Through the optical microscope to observe canine retinal paraffin section,vascular endothelial cells CD105 immunohistochemical staining were positive in group S1,the positive expression rate was 100%;Vascular endothelial cells CD105 immunohistochemical staining in group S2 and S3 were negative,the positive expression rate was 0%.(3)The expression of TGF-?1 m RNA in group S1 was measured significantly higher than that in group S2 and S3 by means of relative fluorescence quantitative PCR method,which was 3.180 times higher than that of group S2(p<0.01),and10.657 times higher than that of group S3(p<0.01).The expression of TGF-?1 m RNA in the vitreous body of group S2 was significantly higher than that of group S3,which was 3.351 times higher than that of group S3(p <0.05).The results showed that expression of TGF-?1m RNA in vitreous body of group S1 was the highest,the next was group S2,group S3 was the lowest.Conclusion:(1)Based on the diabetes model dogs,exogenous injection of VEGF in vitreous body can increase the permeability of retinal blood vessel wall,accelerate vascular leakage,promote the formation of canine proliferative diabetic retinopathy.(2)VEGF can significantly increase the expression of TGF-?1 m RNA in vitreous body,and has a positive regulation effect,and accelerate the formation of retinal neovascularization.