Splanchnic bed utilization of leucine and phenylalanine in humans

A refinement of methods to trace the fates of dietary amino acids was investigated by comparing differences in the sequestration of phenylalanine and leucine. These amino acids have different fates, as phenylalanine is oxidized in the liver and leucine by extrahepatic tissues. The moethod used in the study allowed the determination of the differential fates of enterally versus intravenously administered tracers, thus giving better estimates of kinetic parameters of amino acid and protein metabolism.