Arachidonic acid stimulates the formation of 1,2-diacylglycerol and phosphatidic acid in human platelets. Degree of phospholipase C activation correlates with protein phosphorylation, platelet shape change, serotonin release, and aggregation - Siess, W; Siegel, F L; Lapetina, E G (J Biol Chem, 1983)