Phospholipases A2 are found in most mammalian tissues as well as in venoms of insects and snakes. These contain large amounts of melittin, a peptide of 26 amino acid residues that acts as an activator of phospholipases A2.
When the fatty acid released from the 2-position of glycerol is arachidonic acid, the metabolism thereof by cyclooxygenase or lipoxygenase lead to eicosanoids, among which prostaglandins and leukotrienes, which are mediators of inflammation. This is one of the reasons for the violent inflammatory reactions that accompany snake bites and insect bites. Some isoforms of phospholipases A2 could promote the genesis of atheroma, others would be protective.
