title: Hepatic amino-acid metabolism in liver cirrhosis and in the long-term course after liver transplantation.
abstract: The aim of this study was to investigate the impact of orthotopic liver transplantation (OLT) on plasma levels and splanchnic turnover of key amino acids for muscular (branched-chain amino acids: BCAAs) and hepatic metabolism (aromatic amino acids (AAAs) and methionine) in 48 patients with cirrhosis, 14 patients after OLT, and 46 controls. Also, hepatic amino-acid supply and resting energy expenditure were measured. BCAA levels (no hepatic uptake) decreased in cirrhosis (P<0.001) and were improved, although not normalized, after OLT (P<0.001). AAA and methionine levels were raised in cirrhosis (P<0.001) and normalized after OLT (P<0.001). Hepatic supply of these amino acids increased in patients graded Child B and C and decreased significantly after OLT. Splanchnic uptake of AAAs and methionine increased significantly in Child-B and decreased in Child-C patients. After OLT, splanchnic extraction of AAAs and methionine was as in Child A. Circulating AAAs and methionine correlated with indocyanine-green half-life (r=0.71, P<0.001) and resting energy expenditure (r=0.50, P<0.001), indicating that levels of circulating AAAs and methionine in cirrhosis are determined by hepatic and extra-hepatic metabolic factors. This study demonstrates persistent changes in muscular metabolism of BCAAs after OLT, while the hepatic amino-acid metabolism is normalized due to (1) a significant reduction in the rate of peripheral proteolysis, and (2) improved liver function compared with that in patients with cirrhosis.
authors.affiliation: Department of Gastroenterology and Hepatology, Hanover Medical School, Carl-Neuberg-Strasse 1, 30623 Hanover, Germany.
authors.forename: Uwe J F
authors.initials: UJ
authors.lastname: Tietge
authors.forename: Matthias J
authors.initials: MJ
authors.lastname: Bahr
authors.forename: Michael P
authors.initials: MP
authors.lastname: Manns
authors.forename: Klaus H W
authors.initials: KH
authors.lastname: Böker
mesh_terms: D000328:Adult; D024322:Amino Acids, Aromatic / Q000097:blood*; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008099:Liver / Q000098:blood supply / Q000378:metabolism*; D008102:Liver Circulation; D008103:Liver Cirrhosis / Q000378:metabolism* / Q000601:surgery*; D016031:Liver Transplantation; D008297:Male; D008715:Methionine / Q000097:blood; D008875:Middle Aged
chemical_list: D024322:Amino Acids, Aromatic; D008715:Methionine