Soluble Guanylate Cyclase Redox State and Usefulness of Nitric Oxide-Enhancing Drugs in Monocrotaline-Induced Pulmonary Hypertensive Rats

Background: The heme moiety of soluble guanylate cyclase (sGC), an important target of nitric oxide (NO), exists as a mixed configuration: the reduced, oxidized, and heme-free form. Since NO can activate only the first configuration, a change from the NO-sensitive reduced form to the NO-insensitive oxidized/heme-free form results in reduced NO bioavailability. This study was carried out to investigate whether disruption of the sGC redox equilibrium is seen in pulmonary hypertension (PH) and whether treatment with NO-enhancing drugs can halt the disease progression.