ObjectivesTo investigate the expression of E-selectin of adhesive molecule in microvessels in rats′ retina with diabetic retinopathy (DR) at the early, middle, and late phase.MethodsNinety Sprague Dawley (SD) male rats were randomly divided into normal control group (6, 9, and 12 months subgroups with 10 rats in each subgroup) and streptozotocin (STZ) DR group (6, 9, 12 months subgroups with 20 rats in each subgroup). The DR model was set up by one-off celiac injection with STZ at a dose of 60 mg/kg. The rats were executed according to the different time points, and the eyeballs were removed and the digested stretched preparations of retinal microvessels were made. E-selectin of adhesive molecule in microvessels was revealed by EnVision immunohistochemical staining, and the expression of E-selectin in retinal microvessels and the morphological changes were analyzed and observed by Leica-Q550W computer image analytical equipment. The relativity between degree of impairment of DR and expression of E-selectin was detected.ResultsMorphological changes: hyperplasia of endotheliocytes and decreased pericytes were found in 6month DR group; irregularly arranged retinal capillary networks, obviously thickened basilar membrane, many aggregation and adhesion of leucocytes to capillary walls, large areas of acellular capillaries, and opoptosis of endotheliocytes and pericytes were found in 9-and 12-month DR group. Results of quantitative analysis: there was no expression of E-selectin in normal control group, while expression of E-selectin with different degree in each DR group was found. There was significance difference among DR subgroups (Plt;0.01), and the highest expression was found in 6-and 12-month DR group.ConclusionsThe expression of adhesive molecule in microvessels in rats' retina increases as the disease course of DR extends, and has positive correlation with the degree of impairment of microvessels in DR. (Chin J Ocul Fundus Dis, 2005,21:318-321)