[Sar1, Ile8]-Angiotensin II (TFA) has multiple effects on vascular smooth muscle, including contraction of normal arteries and hypertrophy or hyperplasia of cultured cells or diseased vessels. [Sar1, Ile8]-Angiotensin II (TFA) activates both the NADPH and NADH oxidases, and stimulates superoxide anion formation in vascular smooth muscle cells.