Cytochrome P-450-related arachidonic acid metabolites.
Arachidonic acid (AA) can be metabolized to diverse products that differ widely in their biologic activities. Depending on the cell type, AA can be metabolized by 3 pathways: cyclooxygenase, lipoxygenases, and cytochrome P-450 monooxygenases. Disease states, injury, and stress, will influence the enzymes that regulate the breakdown of AA and may favor the generation of products not usually associated with a tissue. Studies on renal eicosanoid mechanisms (all AA metabolites) can serve as a paradigm for other tissues and organs. Discrete stimulation of renal AA metabolism can occur-localized to specific cells within segments of the nephron; for example, cells of the medullary segment of the thick ascending limb of the loop of Henle (mTALH) have high cytochrome P-450 monooxygenase activity, through which novel AA metabolites are formed. These metabolites have characteristic biologic activities, inhibition of Na+-K+-ATPase activity and relaxation of blood vessels, and can be stimulated by peptide hormones. Cytochrome P-450-dependent monooxygenases are also present in the lung where, in their suggested capacity as oxygen sensors, they generate metabolites of AA that modify pulmonary vasomotion.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D015232:Dinoprostone; D007668:Kidney / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011458:Prostaglandins E / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D001095:Arachidonic Acids; D011458:Prostaglandins E; D016718:Arachidonic Acid; D003577:Cytochrome P-450 Enzyme System; D011451:Prostaglandin-Endoperoxide Synthases; D000254:Sodium-Potassium-Exchanging ATPase; D015232:Dinoprostone