Background Mitochondria are the primary sites for ROS production within cells,Tempol(4-Hydroxy 2,2,6,6,tetramethyl piperidine)is a classic compounds targeting ROS scavengers in mitochondria.Objective To investigate the effects of Tempol on aortic function and remodeling in renovascular hypertensive rats.Methods The 2 kindey 1 clip hypertensive model was established in 24 male Wista rats and randomized to untreated hypertensive rats(n=6) or treated with Tempol(1 mmol/L) in drinking water(n=6) for 8 weeks.BP blood plasma angiotensinⅡ(AngⅡ),nitric oxide(NO),8-iso-PGF_(2?) level were determined.Isometric tension change of aortic rings were recorded;RT-PCR were used to measure the expression of NADPH p22 phox mRNA of aorta.Results Hypertensive rats had highter BP,AngⅡ,8-iso-PGF_(2?),media wall,media wall/lumen(W/L)(P