Involvement of phospholipase A2 in neurodegeneration.

Phospholipases A2 are a heterogeneous class of enzymes that hydrolyse fatty acids from the sn-2 2 position of membrane phospholipids. Prolonged stimulation of phospholipase A2 may damage membrane integrity, not only because of the loss of essential phospholipid from the lipid bilayer but also as a result of an uncontrollable Ca2+ influx. The increased levels of intracellular Ca2+ may be responsible for enhanced lipolysis, proteolysis and DNA fragmentation. This process along with the accumulation of lipid peroxidation products may be associated with neurodegeneration in acute neural trauma (ischemia, head and spinal cord injuries) and neurodegenerative diseases (Alzheimer's disease).