Prostaglandins: The prostaglandins are a member of the eicosanoid family. The prostaglandins were first identified in human semen and were thought to be a product of the prostate. However, this was found to be incorrect as they were synthesized in the seminal vesicles. The prostaglandins have a broad array of effects including inflammation, vasodilation, effects on smooth muscle, pain, fever and GI protection. Arachadonic acid is the primary precursor for all the eisosanoids and for the prostaglandins in particular. There are several forms of cylcooxygenase that convert arachadonic acid into an intermediary products: PGG2 and PGH2. These products are then converted to the prostaglandins ( PGE₂, PGF_2a, PGD₂) as well as the prostacylcins (PGI₂, 6-oxo-PGF_1a ) and thromboxanes.