Phospholipase A2 ( EC 3.1.1.4 , PLA2 ) belongs to a family of enzymes that catalyze the hydrolysis of an ester linkage in the sn-2 position of glycerophospholipids free fatty acids ( TC) , including arachidonic acid (AA ) and lysophospholipids . These compounds may act as secondary messengers in the central nervous system ( CNS). Under physiological conditions, cPLA2 is responsible for the level of KT in cell membranes , stability and fluidity of the membranes and transport processes . CPLA2 activation is caused by an increase in intracellular calcium ion concentration , and phosphorylation of the enzyme protein kinase C ( PKC ) , MAP kinase ( mitogen - acitvated protein kinase) , protein kinase -dependent cGMP ( PKG ) and possibly other kinases . KA excessively released can further be metabolized to bioactive eicosanoids , accompanied by the formation of free radicals , especially O2 - , resulting in neuronal degeneration . In Parkinson's disease (PD ) and other neurodegenerative diseases has been observed activation of phospholipase A2 ( PLA2 ), an increase of AA , the induction of COX -2 (cyclooxygenase 2 ) and an increase in prostaglandin synthesis . The above- mentioned changes cause neurotoxic effects in the brain , and suggest their role in the pathogenesis of Parkinson's disease .