Contractile responses to human urotensin‐II in rat and human pulmonary arteries: effect of endothelial factors and chronic hypoxia in the rat

Abstract

Responses to human urotensin‐II (hU‐II) were investigated in human and rat pulmonary arteries. Rat pulmonary arteries: hU‐II was a potent vasoconstrictor of main pulmonary arteries (2–3 mm i.d.) (pEC₅₀, 8.55±0.08, n=21) and was ∼4 fold more potent than endothelin‐1 [ET‐1] (Pmax was considerably less (∼2.5 fold, PPPmax was enhanced ∼1.5 fold in the presence of N^ω‐nitro‐L‐arginine methylester (L‐NAME, 100 μM, PPBritish Journal of Pharmacology (2000) 130, 201–204; doi:10.1038/sj.bjp.0703314