Premium
UTP induced inotropic effects in the human atrium
Author(s) -
Neumann Joachim,
Simm Andreas,
Silber Rolf Edgar,
Gergs Ulrich
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.769.10
Subject(s) - inotrope , tachyphylaxis , adenylyl cyclase , receptor , contraction (grammar) , medicine , phospholipase c , endocrinology , atrium (architecture) , chemistry , p2y receptor , agonist , atrial fibrillation
In humans, UTP levels are increased during myocardial infarction. UTP can act via G protein‐coupled P2Y receptors, which are further divided into P2Y 2, 4, 6, 11, 12, 13, 14 receptors. The inotropic effects of UTP in the human heart have hitherto not been studied. Therefore, we looked for contractile effects in isolated electrically driven (1 Hz) atrial preparations from patients undergoing cardiac bypass surgery. In these preparations UTP (cumulatively applied as 10, 30, 100 μM) concentration‐dependently exerted a positive inotropic effect. At 100 μM UTP (the highest concentration investigated) force of contraction was increased by 21 ± 6% of pre‐drug value (n = 10, p < 0.05). The effect of UTP (100 μM), non‐cumulatively applied, was more pronounced (by 53%, n = 7, p < 0.05) and was stable up to 20 min. The effect could be washed out and could be elicited again, arguing against tachyphylaxis. The inotropic effect occurred without changes in time parameters of contraction. The positive inotropic effect of UTP was not attenuated by pre‐incubation with inhibitors of adenylyl cyclase activity (SQ22536, 10 μM) or phospholipase C (U73122, 10 μM). In summary, we describe inotropic effects of UTP on force of contraction in the human atrium, which occur independently of cAMP and IP 3 . The exact receptor subtypes need to be elucidated.