MISSING LINKS - CYTOCHROME-P450 ARACHIDONATE PRODUCTS - A NEW CLASS OF LIPID MEDIATORS

Three major enzyme systems-cyclooxygenases, lipoxygenases, and cytochr ome P450 monooxygenases (CYP)-generate biological mediators from arach idonic acid (AA). A distinct profile of arachidonate products characte rizes each venal tubular segment and each section of the venal vascula r tree from arteries to microvessels to veins. The most recent discove ries on renal mechanisms subserved by arachidonate metabolites relate to CYP pathways of AA metabolism. These arachidonate products have pro minent effects on blood vessels and ion transport, including modulatio n and mediation of the actions of vasoactive hormones. The diverse pro perties of these AA metabolites and the wide distribution of the CYP s ystem make them prime candidates for participation in regulatory mecha nisms that affect the circulation and transporting epithelia. CYP-AA p roducts are as important to renal and circulatory control as are nitri c oxide and prostaglandins.