Abstract
The utilization of amino acids for gluconeogenesis by rat liver develops in postnatal life, reaching maximum activity at the 5th day. The activity of aspartate transaminase shows a similar trend in post-natal development and the increased activity appears to be due to the soluble enzyme. The activity of alanine transaminase is low in foetal and postnatal rat liver and increases in activity at about the 20th day. Aspartate, glutamate and alanine make a major contribution to gluconeogenesis in the postnatal rat liver.