Liver albumin synthesis increases in free ribosomes during the acute-phase reaction

Albumin concentration in the blood, and its synthesis by the liver, decrease in the rat during the acute-phase response to inflammation. In this paper we show that 24 hours after turpentine treatment free ribosomes from rat liver double their albumin synthesis and release preproalbumin in the cytosol. albumin mRNA from free polysomes, tested in reconstructed systems in vitro, directs the synthesis of preproalbumin which is correctly processed in the presence of microsomal membranes. Albumin mRNA in the free ribosomal fraction decreases in amount, but it is mainly associated with the heavier polysomal fraction. These data favor the hypothesis of a more, efficient utilization of the reduced amount of albumin mRNA, concurrent with failure of translational arrest of the nascent chain and with the release of unprocessed product in the cytosol.