Human albumin synthesis via an albumin precursor in liver tissue slices

A percursor of plasma albumin on man was identified in liver obtained from cadaver renal transplant donors. After 30 incubation with 14C-(U) leucine, most of the labeled immunoreactive albumin was identified as proalbumin, as was evident from its characteristic elution profile on DEAE cellulose 52. After an additional 30 min incubation with unlabeled leucine (60 min total), no precursor form could be identified and the label coeluted with serum albumin. These data strongly suggest that human albumin is initially synthesized in a precursor form and is subsequently transformed into serum albumin.