My research interest is studying the role of oxidative stress and endothelin in moderate and severe renovascular hypertension (RVH).The hypothesis being tested is that moderate renovascular hypertension represents a physiological uncoupling between Angiotensin II and fluid retention, which gives prominence to oxidative stress and endothelin in the maintenance of hypertension. In contrast, severe RVH is accompanied by volume depletion that shifts to renin the maintenance of hypertension. Our studies will define these relationships by using a swine model of RVH in which total renal blood flow, intrarenal hemodynamics, gomerular filtration rate, and tubular fluid dynamics are correlated in stented and contralateral kidneys of pigs with RVH, measured by electron beam computerized tomography, with intrarenal oxygenation, estimated by the blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) methodology.