PLA 2 catalyzes the hydrolysis of the sn-2 acylester bond of phospholipids, yielding a free fatty acid and a lysophospholipid. Arachidonic acid is a precursor molecule for important lipid mediators such as leukotrienes, prostaglandins and thromboxanes, collectively called eicosanoids. The level of free arachidonic acid in the cell is usually low since the majority of arachidonic acid is esterified at the sn-2 position of phospholipids. Mammalian cells contain several different PLA 2 enzymes, each capable of releasing arachidonic acid from phospholipids. Both eicosanoids and PAF are involved in inflammatory reactions.
Atherosclerosis is a disease of large and medium-sized arteries.
The athersosclerotic plaque exhibits some features similar to those of chronic inflammation. Furthermore, PLA 2 enzymes have been implicated in the pathogenesis of atherosclerosis. Both healthy and diseased airteries possessed substantial PLA 2 activity and expressed sPLA 2 group IIA protein. The expression of cPLA 2 in atherosclerotic plaques indicate that this enzyme is associated with the inflammatory component of atherosclerosis. PLA 2 has been reported to play a pivotal role in leukotriene synthesis.