Dose-dependent pressor and renal vasoconstrictor effects of iv infusion of increasing concentrations of ANG II, ANG III, and ANG IV. All three ANG peptides increased mean arterial pressure (MAP) and decreased renal cortical blood flow (CBF) in a dose-dependent fashion, exhibiting potency in the order: ANG II > ANG III > ANG IV. ANG II and ANG III also decreased renal medullary blood flow (MBF) at higher doses, whereas ANG IV had no effect. P < 0.05 vs. baseline ANG IV response (*), vs. baseline ANG III response (+), and vs. baseline ANG II response (#).