The goal of the present study was to determine the specific role of renal medullary HO-1 in the development of Ang II-dependent hypertension in mouse model by IRMI infusion of either a classical metalloporphyrin-based HO inhibitor, stannous mesoporphyrin (SnMP), or the imidazole-dioxolane HO-1 inhibitor, QC-13. The gene discussed is HMOX1; the disease is hypertensive disorder.