Effect of an intravitreal injection of bevacizumab on the expression of VEGF and CD34 in the retina of diabetic rats

Abstract

To evaluate the efficacy of intravitreal injection of bevacizumab as a preventive intervention of vascular endothelial cell proliferation in the retina of diabetic rats. Fifty-four streptozotocin-induced diabetic Wistar rats were injected intravitreally with 3 µL (25 mg/mL) of bevacizumab into left eyes and 3 µL of saline into the right eyes. Immunohistochemistry and enzyme-linked immunosorbent assays for CD34 and VEGF were used to assess retinal angiogenesis, and transmission electron microscopy was used to evaluate the ultrastructure of retinal capillaries. Retinal expression of VEGF was inhibited 1 week and 1 month after injection (P < 0.01, paired t-test), and the expression of CD34 was not obviously inhibited until 2 months after injection (P < 0.05, paired t-test). Using multiple comparisons between the left eyes of bevacizumab-treated rats, the VEGF expression before injection was higher than at 1 week or 1 month after injection (P < 0.05, Dunnett's t-test), and similar to 2 months after injection (P > 0.05, Dunnett's t-test). The amount of VEGF expression was higher 2 months after injection than 1 week or 1 month after injection, and also higher 1 week after injection compared with 1 month after injection (P < 0.05, Student-Newman-Keuls test). CD34 expression decreased more significantly 2 months after injection compared with before injection, 1 week or 1 month after injection (P < 0.05, Dunnett's t-test). A single intraocular injection of bevacizumab may be beneficial as a therapy for preventing retinal vascular endothelial cell growth in the eyes of diabetic rats.