Studies on diabetic cataract in rats induced by streptozotocin. II. Biochemical examinations of rat lenses in relation to cataract stages.

Biochemical examinations of streptozotocin-induced diabetic cataracts in rats were performed and related to different stages of lens opacifications. Sorbitol levels in lenses showed maximum accumulation at stages I-III and began to decrease from stage IV. Glucose levels indicated a relatively constant accumulation, but became higher between stage V and VI. Fructose levels increased less significantly from stage I-IV, and slightly decreased thereafter. Inositol was not detectable from stage I. The sodium-potassium ratio (Na/K) increased slowly from stage I-IV, and rose remarkably at stage V. Hydration of the lenses showed no change between stage I and IV, and after stage V it rose markedly.