Albumin synthesis and catabolism following partial hepatectomy in the rat. The effects of amino acids and adrenocortical steroids on albumin synthesis after partial hepatectomy

Abstract

Plasma albumin levels were measured in partially hepatectomized, sham operated and control rats. The levels fell in both the partially hepatectomized and sham operated groups; while the latter group returned to normal within a few days, the low plasma albumin in the partially hepatectomized animals was sustained. Albumin synthesis rates in the isolated perfused rat liver were measured in the three groups of animals at varying intervals after partial hepatectomy. There was a significant depression of albumin synthesis rate in terms of both liver and whole animal weights when compared to the sham operated and control animals. This depression was almost completely reversed by the addition of arginine, asparagine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, tryptophan and valine added together to 10 times their normal plasma concentrations. The addition of hydrocortisone had no effect on the albumin synthesis rate after partial hepatectomy. Studies in vivo in the three groups of animals (partially hepatectomized, sham operated and control animals) revealed a fall in the albumin catabolic rate after partial hepatectomy coinciding with the fall in the albumin synthesis rate. An hypothesis whereby the amino acids may have their stimulatory effect is proposed.