[The role of lens epithelium in cataract formation in diabetic rats]

This study was designed to evaluate the changes and the role of lens epithelium in sugar cataract formation, in regard to the fact that the highest level of aldose reductase is found in this layer of lens. By light and electron microscopy, we examined the histological changes of central epithelium in lens of rats made diabetic with streptozotocin (STZ) with or without AL1576, an aldose reductase inhibitor, at varying periods of time ranging from 5 to 40 days after intraperitoneal injection of STZ. Also, we examined Na-K-ATPase activity in lens epithelium of rats with diabetes, diabetes plus AL1576 and normal controls at the time of 30 days. The results showed that the first detectable abnormalities occurred after 15 days of STZ injection and were limited to the lens epithelium; cell edema, intracellular vacuoles and extention of rough endoplasmic reticulum pool were remarkable; that AL1576 could prevent almost all of the lesion mentioned above; and that Na-K-ATPase activity in lens epithelium of rats with diabetes increased at the time of 30 days. The findings suggest that lens epithelium may play an important role in sugar cataractogenesis.