EFFECTS OF AN ALDOSE REDUCTASE INHIBITOR, SNK-860, ON THE HISTOPATHOLOGICAL CHANGES OF RETINAL TISSUES IN A STREPTOZOTOCIN-INDUCED DIABETICRAT MODEL

In order to clarify the mechanism of retinal tissue damage in diabetes mellitus, the effects of the inhibition of aldose reductase on the pa thologic changes in the retina of streptozotocin-induced diabetic (STZ -diabetic) rats were examined histologically and histochemically. The STZ-diabetic animals were maintained with and without peroral administ ration of an aldose reductase inhibitor, SNK-860, and their retinas we re examined microscopically after 12 months. Several abnormal changes observed; folding and edema in the retina, loss of pericytes in the re tinal capillary walls, and thickening of basement membranes in the ret inal capillaries, were significantly inhibited by SNK-860. Some of the se changes were similar to those that had been previously noted in dia betic and galactosemic rats. These data suggest that the enhanced poly ol metabolism may be involved in the diabetic changes of the retina.