Sphingolipids Metabolism Following Cerebral Ischemia

It has been well known that ischemic insults induced the hydrolytic breakdown of polyphosphoinositides by calcium-dependent phospholipase C, and diacylglycerol (DAG) was hydrolyzed to free fatty acids (FFAs) by DAG lipase [1, 2, 11, 22, 26]. The composition of FFAs consists mainly of stearic (C18:0) and arachidonic acids (C20:4). These processes are thought to act at early phase of the ischemia. Prolonged ischemia induces the degradation of membrane phospholipids, and the level of various phospholipids decrease at late phase of the ischemia. To determine a therapeutic time window of the ischemic penumbra, it is essential to evaluate the time course of the degradation of glycerophospholipids.