Effect of Thioacetamide-Induced Sublethal Hepatic Cell Injury On Protein Synthesis. ∗

Abstract

Summary

Electron microscopic and radiochemical studies were performed in mild sublethal hepatic cell injury (cloudy swelling) produced by small peroral doses of thioacetamide. Azurophilia, ribosomes and polyribosomes decreased or disappeared in injured cells at 5 1/2 hours. At 48 hours the cells in the outer portion of the lobule contained a marked increase in ribosomes and polyribosomes, while centrally located cells continued to show evidence of the earlier injury. At 5 1/2 hours after thioacetamide there was a decreased uptake of the label from administered C¹⁴-L-leucine in serum albumin and in total hepatic protein while it was increased in the hepatic RNA-protein. These findings were interpreted to indicate that incorporation of amino acid into hepatic RNA-protein is not measurably impaired by mild injury due to thioacetamide, but that synthesis or secretion of serum albumin is impaired. At 48 hours, amino acid incorporation in total hepatic protein was decreased in thioacetamide treated animals, but the incorporation in hepatic RNA-protein and in serum protein did not differ from controls. The interpretation of results at 48 hours was complicated by the joint presence of persistently injured centrilobular liver cells and peripherally located liver cells which contained an increased number of ribosomes.