Study of Albumin Synthesis in Relation to Urea Synthesis

Abstract

Albumin synthesis in the isolated perfused rabbit liver was simultaneously measured immunologically and by the 14C-CO2 method. Since this 14C method requires the assay of synthesized urea carbon-specific activity, urea synthesis was varied by dietary alterations and by perfusion with alcohol, tryptophan, arginine, and ornithine. Albumin synthesis rates, determined by the two methods agreed well over a 10-fold range of albumin and urea synthesis rates. Perfusion with arginine or ornithine increased albumin synthesis 3-fold compared with fasted control values. These data suggest that, kinetically, arginine can be considered to act as a single precursor pool for albumin and urea synthesis, and support the validity of the 14C-CO2 method in vitro.