title: Acceleration of contraction by beta-adrenoceptor stimulation is greater in ventricular myocytes from failing than non-failing human hearts.
abstract: Myocytes from failing human ventricle contract and relax more slowly than those from non-failing. This has been suggested to result from the lowering of basal cyclic AMP level in failing myocardium, and the consequent withdrawal of a tonic lusitropic effect. We present data to support this hypothesis by demonstrating that the acceleration of contraction and relaxation by beta-adrenoceptor stimulation is greater in myocytes from failing than non-failing heart. This is despite the desensitisation of the inotropic effect of isoprenaline in the same failing cells. Following beta-adrenoceptor stimulation, speeds of contraction and relaxation are normalised in myocytes from failing heart, with final values not significantly different from non-failing.
authors.affiliation: National Heart & Lung Institute, Dept. Cardiac Medicine, London, UK.
authors.forename: S E
authors.initials: SE
authors.lastname: Harding
authors.forename: L A
authors.initials: LA
authors.lastname: Brown
authors.forename: F
authors.initials: F
authors.lastname: del Monte
authors.forename: C H
authors.initials: CH
authors.lastname: Davies
authors.forename: P
authors.initials: P
authors.lastname: O'Gara
authors.forename: G
authors.initials: G
authors.lastname: Vescovo
authors.forename: D G
authors.initials: DG
authors.lastname: Wynne
authors.forename: P A
authors.initials: PA
authors.lastname: Poole-Wilson
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D001706:Biopsy; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D006333:Heart Failure / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*; D013268:Stimulation, Chemical; D016276:Ventricular Function
chemical_list: D000318:Adrenergic beta-Agonists; D011943:Receptors, Adrenergic, beta; D000242:Cyclic AMP; D007545:Isoproterenol; D002118:Calcium