Effect of Dietary Restriction with and without Excess Leucine on Hepatic Tryptophan Oxygenase, 3-Hydroxyanthranilate Oxygenase and Leucine Aminotransferase in Rats

Abstract

Tryptophan oxygenase (EC 1.13.1.12), 3-hydroxyanthranilate oxygenase (EC 1.13.1.6) and leucine aminotransferase (EC 2.6.1.6) activities were determined in livers of rats subjected to different dietary restrictions, with and without excess leucine. The activities of all three enzymes were significantly increased with undernutrition in animals not receiving excess leucine. Excess leucine with moderate undernutrition (50% ad libitum intake) further induced this effect while excess leucine with severe restriction (25% ad libitum intake) acted in the opposite direction.