Hydroxyl radical formation in phagocytic cells of the rat

Abstract

Polymorphonuclear leukocytes (PMN) and macrophages, harvested from the peritoneum and lung, release superoxide .**GRAPHIC**. and hydrogen peroxide (H2O2) during phagocytosis. These 2 agents are thought to react with each other to produce a highly active oxidative substance known as hydroxyl radical (OH.cntdot.). These radicals are apparently generated by phagocytic cells of the rat. The findings were based on an assay where ethylene gas is generated from methional by the action of this radical. Ethylene generation was inhibited by superoxide dismutase, catalase and scavengers of OH.cntdot.. Of the cells examined, PMN generated the most ethylene from methional, exhibiting a 4-fold increase during phagocytosis. Pulmonary and peritoneal macrophages caused smaller amounts of this gas to be formed. Regardless of cell type, an intact cell was required for ethylene generation. Zymosan appeared to be the most effective particle for all cells in ethylene formation from methional, although opsonization was critical only for PMN. Ethylene generation was dependent on cell concentration to an extent and increased with time.