caa a22 4500 46907955X CHVBK 20180323132946.0 cr unu---uuuuu 170328e19920401xx s 000 0 eng 10.1007/BF00176614 doi (NATIONALLICENCE)springer-10.1007/BF00176614 A 5-HT4-like receptor in human left atrium [Elektronische Daten] [Louise Sanders, Alberto Kaumann] Summary: The effects of 5-hydroxytryptamine (5-HT) on left atrial preparations obtained from 5 patients with terminal heart failure who were undergoing heart transplant surgery were investigated. The preparations were paced under isometric conditions. In the presence of (−)-pindolol I pmol/l (to block β-adrenoceptors) and cocaine 6 gmol/l (to block tissue uptake of 5-HT) 5-HT increased contractile force with a pEC50 of 7.0. The maximum effect of 5-HT amounted to 24.5% of that caused by a maximally effective concentration of (−)-isoprenaline (200 μmol/l) and 25% of that caused by 6.75 mmol/l CaCl2. The, effects of 5-HT were competitively antagonised by 3α-tropanyl-1H-indole-3-carboxylate (ICS 205-930) with a pKB of 6.8. The effects of 5-HT on cyclic AMP levels and cyclic AMP-dependent protein kinase activity were also studied using left atrial tissues from one of the patients; 5-HT increased the cyclic AMP content and stimulated the kinase. The results are consistent with the existence of a human left atrial 5-HT receptor which is similar to the recently identified human right atrial 5-HT receptor that resembles the 5-HT4 receptor. The left atrial 5-HT4-like receptor is functional in tissues obtained from patients with terminal heart failure. Springer-Verlag, 1992 Human left atrium nationallicence 5-Hydroxytryptamine nationallicence Positive inotropism nationallicence 5-HT4 receptor nationallicence Heart failure nationallicence Sanders Louise Clinical Pharmacology Unit, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, CB2 2QQ, Cambridge, UK aut Kaumann Alberto Clinical Pharmacology Unit, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, CB2 2QQ, Cambridge, UK aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/4(1992-04-01), 382-386 0028-1298 345:4<382 1992 345 210 https://doi.org/10.1007/BF00176614 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00176614 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sanders Louise Clinical Pharmacology Unit, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, CB2 2QQ, Cambridge, UK aut NATIONALLICENCE 700 1- Kaumann Alberto Clinical Pharmacology Unit, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, CB2 2QQ, Cambridge, UK aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/4(1992-04-01), 382-386 0028-1298 345:4<382 1992 345 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer