Cyclooxygenase(COX) adds molecular oxygen to arachidonic acids to form PGG₂ and then PGH₂. Inhibition of the cyclo- oxygenase activity of COX is responsible for the anti-inflammatory activity of aspirin and other non-steroidal anti-inflammatory drugs. COX-1 and COX-2 have been extensively characterized and the transcription of both COX-1 and COX-2 genes is highly regulated. Given issues regarding toxicity of both COX-1 and COX-2 inhibitors, there is renewed interest in down-stream enzymes that catalyze production of specific prostanoids. Microsomal PGE synthase (mPGES) produces PGE₂, a major mediator of inflammation. The co-localization of mPGES with COX-2 and their coordinated upregulation in several tissues strongly supports an intergral role for this enzyme in inflammatory reactions. PGD₂ is another major prostaglandin formed in a variety of tissues and involved in many physiological events. Two types of PGD synthase have been reported. One is glutathione (GSH) requiring PGD synthase and the other is GSH-independent PGD synthase.

Lipoxygenases (LOX) are non-heme iron-containing dioxygenases. Arachidonic acid is the most important substrate for most mammalian lipoxygenases, and these enzymes are designated accord-ing to the specific positional oxygenation of arachidonic acid. 5-,8-,12-, and 15-oxygenated deriva-tives of arachidonic acid have all been demonstrated to produce a wide range of physiologically active metabolities. Lipoxygenases catalyze the committed steps in pathways leading to a wide variety of bioactive lipids including hydroxyl- and hydroperoxy-derivatives, as well as leukotrienes.

  The central role of eicosanoids in inflammation and in the etiology of many diseases is now widely recognized. In addition to the COX and LOX pathways, certain cytochromes P450 produce potent epoxy and hydroxyl derivatives of arachidonic acid. Among these, 20-HETE has been extensively studied based on its role in hypertension. Phospholipase A2 (PLA2) enzymes liberate membrane bound arachidonic acid required for all of these pathways. To support ongoing research into the enzymes of eicosanoid metabolism, we also provide ram seminal vesicles (the original source from which purified COX-1 was obtained, and a rich source for many eicosanoid-metabolizing enzymes) as well as seminal vesicle microsomes. We also continue to collaborate with scientists world-wide to develop new assays for eicosanoids and new applications. For example, although PGF2alpha is historically associated with reproductive physiology, Samar Basu and others have clearly demonstrated that 15 keto-dyhydro-PGF2alpha is an excellent biomarker for inflammation.