Apocynin decreased p22phox mRNA levels in aorticsegments from aldosterone-salt male Sprague-Dawley (SD) rats and impededp47phox subunit assembly within the membrane complex in human endothelial cellsto inhibit the activity of NAD(P)H oxidase and its production of superoxide.Apocynin prevents and reverses adrenocorticotropic hormone- (ACTH-) inducedhypertension [2, 49], indicating that NAD(P)Hoxidase is a major enzymatic source of superoxide overproduction in rat modelof both naturally occurring and synthetic hypertension. This evidence concerns the gene FMO5 and hypertensive disorder.