Abstract
Depression of the reticuloendothelial system (RES) was observed in rats following operative trauma consisting of laparotomy and jejunal enterotomy. This RES depression was manifested as a significant impairment in the phagocytic clearance of intravenously injected blood-borne test colloid mediated by a decline in hepatic Kupffer cell phagocytosis. Reticuloendothelial systemic host defense depression was correlated with a significant decline in bioassayable and im-munoreactive opsonic a2SB glycoprotein concentration over a 1–3 hr postoperative period with rebound elevation in opsonic activity by 24 hr postsurgery. Intravenous administration of purified opsonic a“SB glycoprotein at the end of the operation prevented postoperative opsonic deficiency and restored normal hepatic RES phagocytic function. These studies coupled with previous observations in patients following surgery or after severe multiple trauma suggest that reticuloendothelial depression during and after operation mediated by opsonic deficiency may lead to a precarious imbalance between systemic host defense and the dissemination of blood-borne foreign and effete particulate matter such as injured platelets, fibrin microaggregates and immune complexes. Immunoreactive serum opsonic α2SB glycoprotein determinations may serve as a valuable index of hepatic RE clearance capacity and opsonin therapy may potentially be a selective means to augment systemic host defense.