Glycosidases of the crystalline lens. II. Alterations in diabetic cataracts.

Six glycosidases were determined in: (1) lenses of alloxan-diabetic rats; (2) rabbit lenses incubated in high-glucose media in vitro; and (3) human senile cataracts, diabetic senile cataracts, and autopsy lenses. In diabetic rat lenses, the activities of /3-glucosaminidase, fi-galactosidase, and P-fucosidase increased with cataract progression as compared to control lenses. Glycosidase activities, however, did not differ in human diabetic cataracts (patients with normal blood glucose levels) as compared to human senile cataracts or autopsy lenses. Incubation of rabbit lenses in high-glucose Tyrode's media did not affect the glycosidase activities as compared to rabbit lenses incubated in normal Tyrode's media.