Hepatic macrophage malfunction in rats with obstructive jaundice and its biological significance

The present study was designed to investigate the pathophysiology of obstructive jaundice by analyzing the function of hepatic macrophages and their role in immune responses and homeostasis in rats. The phagocytic index, determined by the rate of disappearance of 51Cr-endotoxin from the peripheral blood after intravenous injection, was increased in obstructive jaundice 2 weeks after bile duct ligation. The superoxide production of isolated hepatic macrophages and peripheral blood monocytes, measured by the superoxide dismutase inhibitable ferricytochrome c reduction method, was increased. Prostaglandin E2 release, measured by RIA, was markedly increased in rats with obstructive jaundice, but there was no significant difference in interleukin-1 release between jaundiced and control rats. The flow-cytometric analysis of surface molecules of hepatic macrophages showed decreased expression of interleukin-2 receptor in rats with obstructive jaundice. Thus, the functions of hepatic macrophages in rats with obstructive jaundice were impaired. This malfunction may disturb the immunoregulatory network and metabolism, although the exact implications of the altered function of hepatic macrophages have not yet been clarified.