ACE and Hypertension: By using captopril (ACE inhibitor), compound 21 (AT2 receptor agonist), fenoldopam (D1 receptor agonist), PD123319 (AT2 receptor antagonist), L-NMMA (NOS inhibitor), indomethacin (COX inhibitor), and icatibant (B2 receptor antagonist), they showed a complex and intricate interaction and relationship between Ang II, Ang-(1-7), dopamine, BK, NO, PGs, and cyclooxygenase systems in the kidney that, beyond regulation of physiological hemodynamic of kidney, participates in the development of hypertension.