Ernst Wertheimer

Interrelation between the various pathways of glucose metabolism in the rat lens

The activity of the hexose monophosphate shunt in the rat lens rose in proportion to the increased concentrations of glucose in the incubating medium. Under the same conditions, lactic acid production increased only up to 50%. Preincubation of the lens with dulcitol caused a depression of both the glycolysis and the hexose monophosphate shunt. The shunt activity was increased in the presence of added insulin when the medium contained 1·0 mg of glucose, or less, per ml, but it was not affected by the presence of 2·0 mg of glucose per ml. Incubation in media containing increasing concentrations of fructose caused a proportional rise in lactic acid production. The addition of pyruvic acid to the medium enhanced the hexose monophosphate shunt, whereas lactic acid depressed it. Some interrelationships between the sorbitol pathway, the hexose monophosphate shunt and the glycolytic pathway in the rat lens are discussed.