Immune complex metabolism and Fc receptors of the liver sinusoidal cells in various pathological states.

Abstract

To clarify the pathobiology of the Fc receptors in the liver sinusoidal endothelium, the Fc receptors were studied by applying peroxidase-antiperoxidase IgG complexes as a ligand to frozen tissue sections from human cirrhotic livers, rat cirrhotic livers induced with CC14, rat regenerating livers after 70 per cent hepatectomy, livers of NZB/WF1 mice and livers of the mice injected intracutaneously with complete Freund's adjuvant (CFA). The Fc receptors showed a focal absence and the length of the Fc receptor-positive portions of the sinusoids in unit area decleased to about 50% and 60% of the normal value in the advanced cirrhosis in man and rats, respectively. The delayed blood clearance and decreased hepatic uptake of 125I-labeled BSA-antiBSA IgG comlexes were seen in the cirrhotic rats. The Fc receptor activity, estimated by staining intensity of the Fc receptors, was considerably decreased is the regenerating livers for 7 days after hepatectomy. The 5-week-to 9-month-old NZB/WF1 mice showed higher Fc receptor activity than control NZW mice. The Fc receptor activity in the CFA injected mice gradually increased until 4 week after administration. The hyperplasia or absence of Kupffer cell was found in these conditions, associated with increase and decrease of Fc receptor activity, but the causative relationship between Kupffer cell number and Fc receptor activity could not be found.