Amino Acid Kinetics During the Anhepatic Phase of Liver Transplantation

Alanine and glutamine are interorgan nitrogen/carbon carriers for ureagenesis and gluconeogenesis, which are mainly but not necessarily only hepatic. The liver is central to alanine and glutamine metabolism, but most organs can produce and use them. We studied amino acid kinetics after liver removal to depict initial events of liver failure and to provide a model to study extra-hepatic gluconeogenesis and nitrogen disposal in hu-mans. We measured amino acid kinetics with [5,5,5-2H3] leucine and [3-13C]alanine or [1,2-13C2]glutamine tracers in 21 subjects during and after the anhepatic phase of liver transplantation: 12 were at 7 months posttrans-plantation, and 7 were healthy control subjects. An-hepatic leucine kinetics, including proteolysis, was unchanged. Alanine plasma and whole-body content