AIM:To investigate the changes of retinal histology and oxidative stress in diabetic retinopathy and its reversal by pyruvate in diabetic rats.

METHODS:Eighty Wistar rats were divided into 3 groups: control group(20 rats), model group(30 rats)and treatment group(30 rats). After streptozotocin(STZ)induced diabetes mellitus in the model group and the treatment group, the treatment group received 2% pyruvate in diet and drinking. The changes of body weight and blood glucose were observed and the changes of glutathione peroxidase(GSH-PX), malonie dialdehyde(MDA), and Na⁺-K⁺-ATPase levels of retinal tissue and retinal ultrastructure were investigated in three groups at 12wk after occurrence of diabetes.

RESULTS:Compared with control group, the body weight of the model group were significantly decreased, the activities of GSH-PX and ATP in the retina of diabetic rats were significantly lower, the MDA was signigicantly higher and significant changes occurred in retinal ultrastructure. Compared with model group, the blood glucose of the treatment group had no significant changes. However, the activities of GSH and ATP in the retina of diabetic rats were higher, the MDA was lower and the retinal ultrastructure was comparatively mild.

CONCLUSION:Pyruvate can alleviate oxidatie stress reaction, improve the energy metabolism of retina, and delay the development of retinopathy.