Regulation of Prostaglandin Synthesis in Human Vascular Cells (original) (raw)

Metabolism of arachidonic acid in the vascular wall proceeds mainly by way of the cyclooxygenase pathway to prostaglandins; a major prostaglandin product of large vessels is prostacyclin (PGI,), a potent vasodilator and inhibitor of platelet activation. Synthesis of PGI, is regulated by the activities of the enzymes cyclooxygenase (prostaglandin H (PGH) synthase) and PGI, synthase and, to a lesser degree, by the activity of phospholipases A2 and C. Because of the large pool of substrate, namely, arachidonic acid, in the cells, substrate availability infrequently is rate-limiting.