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Cardiostimulant effects of urotensin‐II in human heart in vitro
Author(s) -
Russell Fraser D,
Molenaar Peter,
O'Brien Donalee M
Publication year - 2001
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0703811
Subject(s) - contractility , urotensin ii , medicine , contraction (grammar) , cardiology , muscle contraction , inotrope , endocrinology , chemistry , receptor
The effects of the recently identified human peptide urotensin‐II (hU‐II) were investigated on human cardiac muscle contractility and coronary artery tone. In right atrial trabeculae from non‐failing hearts, hU‐II caused a concentration‐dependent increase in contractile force (pEC 50 =9.5±0.1; E max =31.3±4.8% compared to 9.25 m M Ca 2+ ; n =9) with no change in contraction duration. In right ventricular trabeculae from explanted hearts, 20 n M hU‐II caused a small increase in contractile force (7.8±1.4% compared to 9.25 m M Ca 2+ ; n =3/6 tissues from 2 out of 4 patients). The peptide caused arrhythmic contractions in 3/26 right atrial trabeculae from 3/9 patients in an experimental model of arrhythmia and therefore has less potential to cause arrhythmias than ET‐1. hU‐II (20 n M ) increased tone (17.9% of the response to 90 m M KCI) in 7/7 tissues from 1 patient, with no response detected in 8/8 tissues from 2 patients. hU‐II is a potent cardiac stimulant with low efficacy. British Journal of Pharmacology (2001) 132 , 5–9; doi: 10.1038/sj.bjp.0703811