Dietary Arginine Deficiency Alters Flux of Glutamine and Urea Cycle Intermediates across the Portal-Drained Viscera and Liver of Rats

The effect of an arginine-deficient diet on net flux of amino acids across the portal-drained viscera and across the liver was studied in rats. Blood was obtained after food deprivation and 1 and 2 h after a meal of a 1.0% arginine control diet or an arginine-deficient diet containing 3.4% glutamate. The arginine-deficient diet decreased net portal-drained viscera flux of arginine and increased net portal-drained viscera flux of ornithine and proline. However, net portal-drained viscera flux of citrulline (0.35±0.05)mol/min) was not influenced by diet; of this rate, 46% (0.16)mol/min) bypassed the liver and was available for extrahepatic arginine synthesis