Concentration Dependent Inhibition of Hepatic Gluconeogenesis by Insulin

The rate of gluconeogenesis from Ul-14C-alanine was determined at physiological insulin concentrations in the isolated rat liver perfused with a non-recirculating medium. There was a significant negative relationship between gluconeogenesis and the insulin concentration over the range of 10-500 μU/ml. Increasing the insulin concentration to 1000 μU/ml did not result in any further reduction of gluconeogenesis. Insulin did not alter the gluconeogenic response of the liver to increasing substrate concentrations in these perfusions.