Functional Roles of the P450 Arachidonic Acid Monooxygenase

Functional Roles of the P450 Arachidonic Acid Monooxygenase 

Recent reviews provide excellent and detailed descriptions of the biological roles attributed to the products and enzymes of the AA monooxyge-nase . We address here what we considered to be the two most relevant issues, and for which a more or less generalized consensus exists regarding their potential physiological importance. 

Because of their physiological and pathophysiological implications, the vasoactive properties of EETs and 20-HETE are under extensive scrutiny. The consensus is that EETs (5,6-and 11,12-EET in particular) and 20-HETE are powerful vasodilators and vasoconstrictors of small diameter vascular beds, respectively , and that these actions are associated with their ability to inactivate (20-HETE) or activate (EETs) Ca -activated vascular smooth muscle K channels  

It has been proposed that an EET-mediated hyper-polarization event is required to complete the vasodilatory response of vascular smooth muscle cells to hormones such as, for example, bradykinin 128 -pjje identification of 11,12-EET as an EDHF 2 , and of 20-HETE as an anti-EDHF molecule - - are supported by the demonstration of hormonally controlled 20-HETE and EET biosynthesis by isolated vascular smooth 

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