Ovine Hepatic Metabolism 1. The Effect of Portal Amino Acid Concentration on the Metabolism of Glucose and Urea

摘要

The study was designed to address the hepatic response (urea and glucose production, glycogen synthesis, and oxygen consumption) to physiological changes in Amino Acid (AA) concentrations. To elucidate this objective, Four South African Mutton Merino Wethers weighing 23-33 Kg were used and the caudate lobe of the liver of mean weight 18.70?1.5 g was perfused with modified Krebs-Henseleit medium. Mixtures of amino acids representing Low Nitrogen (LN), High Nitrogen (HN = 3 X LN) and LN or HN plus either extra alanine, lysine, or glutamine, were perfused at a flow rate ranging from 65-100 ml/min. The data indicates an increase in hepatic urea production and a 20-240% decrease in glucose production in response to high amino acid mixture. The inhibition of glucose production was inhibited by 22% for the HN infusion and further 20% by added alanine, lysine or glutamine. However, the addition of amino acid did not affect urea production and the oxygen consumption.