Stimulation of phospholipase A2 activity by oxygen-derived free radicals in isolated brain capillaries

An exogenous free radical generating system added to isolated brain capillaries induces degradation of phospholipids. This inductive effect reflects increased phospholipase activities as measured by fatty acid composition of various phospholipid fractions. The correlation of phospholipid degradation with stimulation of phospholipases was further investigated by using cationic amphiphilic agents, which are known to be phospholipase A2 inhibitors. The breakdown of phospholipids was inhibited by the pretreatment of isolated capillaries with these drugs.