Abstract: To study the effect of osthole on isolated pulmonary arteries by using force-electricity transducers,pulmonary arteries isolated from human beings and healthy SD rats and mesenteric arteries from SD rats were cut into rings (about 3 mm in length) and observed the response of artery contraction to different doses of osthole. The results showed that osthole (10⁹-10⁵ mol/L) relaxed phenylephrine precontrated isolated pulmonary arteries of both human beings and rats in a dose-dependent manner,but not mesenteric arteries and normal pulmonary arteries.Therefore,osthole relaxed human and rat isolated pulmonary arteries in a dose-dependent manner and was tissue specific.

Key words: osthole, pulmonary arterial hypertension, pulmonary arterial rings