Suppression of retinal blood vessel leakage by inhibition of vascular endothlial growth factor using soluble-Flt in experimental diabetic rats / 眼科新进展

ABSTRACT

Objective　Vascular endothelial growth factor (VEGF) can cause potent vascular permeation. More and more findings have demonstrated that VEGF is increased in the diabetic retinopathy. The objective of this study is to investigate whether blocking the VEGF using soluble-Flt can suppress the retinal blood vessel leakage.Methods　Sprague-Dawley rats weighing approximately 200 grams were made diabetic by injection of streptozotocin (STZ). After the animals were diabetic for 1 week, they were intravenously injected with either PBS+50g*L-1Glycerol, interleukin-6 receptor monoclonal antibody (IL-6R), or soluble-Flt. On the eighth day, Evans blue method was used to check the leakage. Animals treated with citrate sodium buffer and STZ treated non-diabetic animals served as the control group. Results　There was no significant difference of the retinal blood vessel leakage between the two control groups (P>0.05). The retinal blood vessel leakage of 8 day diabetic animals was significantly higher than that of total control groups (P<0.05). The leakage of diabetic animals treated with PBS+Glycerol or IL-6R remains the same (P>0.05). But, the leakage of 25 mg*kg-1 soluble-Flt treated diabetic animals was remarkably lower than that before treatment, PBS+Glycerol treated or IL-6R treated diabetic animals (P<0.000 1), and there was no difference compared with total non-diabetic control groups (P>0.05). Conclusion　This study shows that the VEGF plays a very important role in the onset of the diabetic retinopathy and suggests by suppressing the action of VEGF, the retinal blood vessel leakage at the early stage of diabetic retinopathy could be reduced.