AIM: To investigate the expression of connexin43(Cx43)in retina of Sprague Dawley(SD)rats with diabetes mellitus(DM), and the effects of celecoxib, inhibitor of cyclooxygenase 2(COX-2), on expression of Cx43 in retina of them.

METHODS: DM was induced in SD rats by the administration of streptozotocin(STZ). DM rats were divided into two groups: COX-2 treated group(CTG, n=15), and diabetic group(DG, n=15). Normal control group(NCG)consisted of 15 rats was given. Three months' treatment was given after DM development. Sample of retina were made at the end of 3mo. Expression of Cx43 in retina were investigated by immunohistochemistry. Expression of Cx43 mRNA in retina were analyzed by RT-PCR.

RESULTS: Cx43 was expressed in the ganglion cell layer, the nerve fiber layer, the inner plexiform layer, and the pigment epithelium layer of retina with a different degree. Computer image analysis showed that celecoxib had elevated the expression of Cx43 in experimental diabetic rats, gray values were: 0.233±0.025, 0.124±0.014, 0.197±0.021; multiple comparisons found statistically significant difference(P<0.05). Celecoxib had raised the expression of Cx43 mRNA in diabetic rats with real time quantitative PCR. Relative value was 0.635±0.084, 0.110±0.061, 0.367±0.074, multiple comparisons found statistically significant difference(P<0.05).

CONCLUSION: Expression of Cx43 decreases in retina of SD rats with DM. Celecoxib can relieve the decrease of Cx43 expression in retina of them.