Objective To investigate if insulin can affect the expression of vascular endothelial growth factor (VEGF) in the retina of streptozotocin-induced diabetic rats. Methods A total of 60 male SpragueDawley rats were randomly divided into sodium citrate buffer control group (CIT-CON, n=30) and STZ-induced diabetic group (STZ-DM, n=30). At the 16th week, 24 rats from CIT-CON group at random were randomly divided to group A (sodium citrate buffer control group, n=12) and group B (sodium citrate buffer plus insulin group, n=12). The remaining 6 rats from as CIT-CON group served as negative control. At the same time, 24 rats from STZDM group at random were randomly divided to group C (STZinduced diabetic group, n=12) and group D (STZ-induced diabetic plus insulin group, n=12). The remaining 6 rats from STZ-DM group also served as negative control. 4 IU of insulin was injected subcutaneously to rats of group B and D. Immunohistochemistry, Western blot and Real-time polymerase chain reaction (RT-PCR) were used to measure the expression level of VEGF protein and mRNA respectively. RESULTS Insulin significantly increased the VEGF mRNA (7.71 plusmn;0.25 vs 5.36 plusmn;0.37, t test P lt;0.05) and protein expression (0.4925 plusmn;0.0122 vs 0.4272 plusmn;0.0110, t test P lt;0.05) in the retina of CITCON rats. However, in retina of STZDM rats, insulin had no effect on VEGF mRNA (8.92 plusmn;0.27 vs 9.05 plusmn;0.28, t test, P gt;0.05) and protein expression (0.5152 plusmn;0.0109 vs 0.5099 plusmn;0.0100, t test P gt;0.05). Conclusions Insulin had no effect on VEGF expression in the retina of STZ-DM rats.
Citation： 邬海翔,夏欣,顾青,许迅. Insulin has no effect on vascular endothelial growth factor expression in the retina of streptozotocin-induced diabetic rats. Chinese Journal of Ocular Fundus Diseases, 2009, 25(3): 202-205. doi: Copy