Objective: To disclose the relationship between the deposition of advanced glycosylation end products (AGE) in the retinal vascular tissues and damage of retinal vessels in diabetic retinopathy.
Methods: Sixteen SD rats aged 2 months were divided into 4 groups, with 4 rats in each group. Rats in normal group received no treatment. Diabetes was induced by AGE in the diabetes group. Rat serum albumin (RSA, 40 mg/kg weight) was administered daily to healthy non-diabetic rats through tail veins for 2 weeks (RSA group). AGE-modified RSA was injected to rats in another group at the same route and dosage (AGE-RSA group). The number of pericytes in retinal capillary vessels was counted 2 weeks later.
Results: After two weeks continuous AGE treatment, the average amount of pericytes of capillary vessel per 10 microscope visual field (x 100 magnification) in AGE group (4.31 +/- 0.34) was significantly less than that of RSA group (5.80 +/- 0.48) (P < 0.01). Meanwhile, in the AGE-RSA group, AGE were identified in the retinal vascular tissues by immunohistochemical staining.
Conclusion: Injection of exogenous AGE into healthy rats induces vascular changes resembling those find in the diabetic retinopathy. AGE might be one of the independent pathogenic factors in the occurrence of diabetic retinopathy.