ROLE OF NONPARENCHYMAL LIVER-CELLS IN ACTIVATION OF PROTEIN-SYNTHESIS IN HEPATOCYTES ON STIMULATION OF THE MONONUCLEAR PHAGOCYTE SYSTEM BY LIPOPOLYSACCHARIDE

The rate of protein synthesis in hepatocytes was found to significantly depend on the functional state of non-parenchymal (NP) liver cells, Kupffer cells in particular. Stimulation of these cells in vivo with lipopolysaccharide (LPS), zymosan, or dextran sulfate resulted in a 1.5-2.0-fold increase in the rate oi [C-14]leucine incorporation into hepatocyte protein. A similar effect was observed in a mixed culture of hepatocytes and NP cells isolated from the liver of LPS-stimulated rats, as well as in the presence of incubation medium from NP cells cultured previously with high-density lipoproteins (MDL), LPS, and hydrocortisone. Apoprotein A-1 (the principal protein component of HDL) is suggested to be involved in the enhanced gene expression in hepatocytes on stimulation of resident liver macrophages.