A stimulator of sGC; stimulates recombinant sGC in a concentration-dependent manner in vitro by up to 73-fold at 100 μM or by up to 112-fold when used in combination with DEA NONOate; has no effect on phosphodiesterases PDE1-9 and PDE11 at ≤3 μM; reduces pulmonary and systemic arterial pressure at 1 and 10 mg/kg in a rabbit model of acute PAH induced by U-46619; inhibits increases in right ventricular systolic pressure, right heart hypertrophy, and pulmonary artery muscularization in hypoxia-induced mouse and monocrotaline-injected rat models of chronic PAH at 10 mg/kg