PT - JOURNAL ARTICLE AU - R T Bennett AU - R D Jones AU - A H Morice AU - C F C Smith AU - M E Cowen TI - Vasoconstrictive effects of endothelin-1, endothelin-3, and urotensin II in isolated perfused human lungs and isolated human pulmonary arteries AID - 10.1136/thx.2003.011197 DP - 2004 May 01 TA - Thorax PG - 401--407 VI - 59 IP - 5 4099 - http://thorax.bmj.com/content/59/5/401.short 4100 - http://thorax.bmj.com/content/59/5/401.full SO - Thorax2004 May 01; 59 AB - Background: Urotensin II (UII) has been identified as a ligand for the orphan receptor GPR14 through which it elicits potent vasoconstriction in humans and non-human primates. The pulmonary vasculature is particularly sensitive; human UII (hUII) exhibits a potency 28 times that of endothelin (ET)-1 in isolated pulmonary arteries obtained from cynomolgus monkeys. However, hUII induced vasoconstriction in isolated human intralobar pulmonary arteries is variable, possibly as a result of location dependent differences in receptor density or because it is only uncovered by disease dependent endothelial dysfunction. Methods: The vasoactivity of both hUII and gobi UII (gUII) in comparison with ET-1 and ET-3 was studied in isolated perfused lung preparations (n = 14) and isolated intralobar pulmonary arteries (n = 40, mean diameter 548 (27) μm) obtained from 17 men of mean (SE) age 67 (2) years and eight women of mean (SE) age 65 (3) years with a variety of vascular diseases. Results: ET-1 (10 pM–100 nM) and ET-3 (10 pM–30 nM) elicited vasoconstriction in the lung preparations, inducing comparable increases in pulmonary arterial pressure of 24.8 (4.5) mm Hg and 14.5 (4.9) mm Hg, respectively, at 30 nM (p = 0.13). Similarly, ET-1 (10 pM–300 nM) and ET-3 (10 pM–100 nM) caused marked vasoconstriction in isolated pulmonary arteries, inducing maximal changes in tension of 4.36 (0.26) mN/mm and 1.54 (0.44) mN/mm, respectively, generating −logEC50 values of 7.67 (0.04) M and 8.08 (0.07) M, respectively (both p<0.05). However, neither hUII nor gUII (both 10 pM–1 μM) had any vasoactive effect in either preparation. Conclusion: UII does not induce vasoconstriction in isolated human pulmonary arterial or lung preparations and is therefore unlikely to be involved in the control of pulmonary vascular tone.