Sildenafil treatment decreases angiotensin II levels in the stenotic kidney of renovascular hypertensive mice. Panel A: typical photomacrograph showing the atrophy of the clipped (c) kidney and the hypertrophy of the nonclipped (nc) kidney caused by renal artery stenosis in the 2K1C mice compared with the Sham mice. Images were obtained 28 days after the surgery. Scale bar: 5 mm. Panel B: bar graph shows augmented levels of angiotensin II in the stenotic kidneys of the 2K1C group and the reduction of this peptide by sildenafil. Values are the means ± SEM, n = 8 to 10 per group. *p < 0.05 and **p < 0.01 (ANOVA).