Two-Week, but Not 1-Week, Hypoxic Exposure Enhances Nitric Oxide-Mediated Basal Tone Regulation in Rat Resistance Pulmonary Arteries

We measured internal diameter (ID) changes in resistance and conduit pulmonary arteries of 1- and 2-week hypoxic rats and normoxic control rats in response to nitric oxide synthase (NOS) inhibitors in vivo. At 2 weeks of hypoxic exposure, the ID reduction as a result of NOS inhibition was enhanced within the resistance arteries, but not at 1 week of hypoxia.