Modulation of the macrophage hepatocytotoxicity and plasminogen activator activity of activated macrophages from guinea pigs by serum components from normal human and patients with liver diseases.

Activated macrophages (m phi) exhibited cytotoxic effects on isolated liver cells and produced plasminogen activator (PA) in vitro. A high molecular weight fraction of normal human serum (Fr-1) was shown to reduce the m phi-mediated hepatocytotoxicity and enhance the PA activity of activated m phi. Conversely, a lower molecular weight fraction of serum (Fr-3) was found to enhance the hepatotoxic potential and decrease the PA activity of activated m phi. Although similar effects were seen with serum fraction prepared from patients with acute hepatitis, somewhat different influences were observed with serum components from patients with chronic active hepatitis or liver cirrhosis: Fr-1 from patients with chronic active hepatitis was less active in reducing m phi-mediated hepatocytotoxicity, and and Fr-3 was more active in enhancing it, in comparison with fractions from individuals or patients with active hepatitis. Fr-3 from patients with liver cirrhosis was shown to be remarkably less active in enhancing m phi-mediated hepatocytotoxicity. Furthermore, Fr-1 from patients with liver cirrhosis reduced PA activity, Fr-3 was less active in decreasing such activity. These findings suggest that the serum components may regulate m phi-mediated hepatocytotoxicity as well as PA secretion of activated m phi. Our studies also suggested the possibility that relative doses of these serum components may differ in various pathological conditions of the liver.