Alloxan Diabetes and Demonstrated Direct Action of Insulin on Metabolism of Isolated Perfused Rat Liver

¹ From the Departments of Radiation Biology and Biochemistry, School of Medicine and Dentistry, University of Rochester, Rochester, New York

The direct effect of insulin was studied in intact surviving livers removed from normal and alloxan-diabetic rats and perfused for 4 hours with rat blood containing acetate-1-C¹⁴. Changes due to diabetes per se were a) decreased lipogenesis from acetate, b) increased ureogenesis, and c) increased incorporation of acetate into carbohydrate. The positive effects of insulin consisted of an at least partial correction of the depressed lipogenesis characteristic of diabetes and of fasting, and a net removal of glucose from the perfusate after the 1st hour. The action of insulin was inhibited in most of the experiments with ketotic liver donors, and also in many experiments in which the operative procedure was accompanied by excessive trauma. Insulin administration depressed gluconeogenesis from acetate and lowered ketogenesis in experiments with alloxan diabetic donors.