A study of three enzymes acting on glucose in the lens of different species.

1. The activities of three enzymes which act on glucose, namely hexokinase, aldose reductase and glucose dehydrogenase, were measured in extracts of eye lens from cow, calf, rabbit, rat and guinea pig, and in human cataractous lenses. 2. The K(m) (glucose) of these three enzymes in extracts of cow lens was found to be 0.12mm, 28mm and 690mm respectively. 3. The physiological importance of hexokinase, aldose reductase and glucose dehydrogenase in the lens of normal and diabetic animals is discussed.