Inhibition of Adherence and Phagocytosis of Zymosan Particles by Mouse Peritoneal Macrophages with Hydrocortisone

Abstract

The relationships between adherence of zymosan and phagocytosis by macrophages with the release of 6-keto-prostaglandin F_1α (6KF_1α) and thromboxane B₂ (TXB₂), the stable endometabolites PGI₂ and TXA₂ respectively, from macrophages were investigated with mouse peritoneal macrophages. Zymosan-induced release of 6KF_1α and TXB₂ was inhibited by indomethacin, an inhibitor of cyclo-oxygenase, and by hydrocortisone, an inducer of the inhibitor of phospholipase A₂. Although release of 6KF_1α and TXB₂ was significantly enhanced by the interaction of attachment of zymosan particles to cell membranes, the interaction was inhibited by hydrocortisone, not by indomethacin. From these results it is suggested that phospholipase A₂ participates in the interaction of zymosan particles with cell membranes for the release of 6KF_1α and TXB₂.