Increased phagocytic activity of peripheral blood monocytes after intravenous injection of phospholipase A2 to monkeys

One of the expressions of the activity of phagocytic cells such as monocytes or macrophages in a burst of increased oxidative activity on stimulation. The free oxygen radicals liberated, mainly O−2 and H2O2, lead to chemoluminescence, which is thus a measure of activation. Chemoluminescence also depends on arachidonic acid metabolism, and this depends on phospholipase A2 (PLA2). We modified monocyte activity in monkeys by injecting them i.v. with this enzyme and observed that 30 min after injection, the phagocytic activity of peripheral blood monocytes and the chemoluminescence they emitted was greater than that of controls. We suggest that PLA2 may act as an in vivo immunomodulator in mammals.