title: [The positive inotropic effect after washout of acetylcholine in isolated rabbit hearts].
abstract: OBJECTIVE
  To study the regular pattern and mechanism of positive inotropic effect after washout of ACh (rebound of myocardial contractile force) in isolated rabbit hearts.
  
  
  METHODS
  The changes of myocardial contractile force after perfusion and washout of ACh were observed in isolated Langendorff perfused rabbit hearts.
  
  
  RESULTS
  Maximum rebound rate induced by ACh of 10(-8)-10(-3) mol/L were 2.20% +/- 1.70%, 6.71% +/- 3.40%, 9.18% +/- 3.54%, 14.16% +/- 3.27%, 4.37% +/- 5.86% and 1.03% +/- 6.86%, respectively. Compared with the ACh of 10(-5) mol/L in control group, adrenaline enhanced rebound of myocardial contractile force, maximum rebound rate in adrenaline group was 29.25% +/- 5.83% (P < 0.05), propranolol reduced rebound, and maximum rebound rate in propranolol group was 5.15% +/- 4.45% (P < 0.05), we had not detected rebound of myocardial contractile force in 800 s after addition ACh in verapamil group.
  
  
  CONCLUSIONS
  In isolated rabbit heart, positive inotropic effect after washout of ACh has relevance to the activities of calcium current channel and beta-adrenergic receptor. Perhaps there are some different aspects in the mechanism of positive inotropic effect between perfusion of high concentration and after washout of ACh.
authors.affiliation: Division of Electrophysiology, Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Ministry of Education, Shihezi University School of Medicine, Shihezi 832002, China.
authors.forename: Hai-Jian
authors.initials: HJ
authors.lastname: Luo
authors.forename: Feng-Jie
authors.initials: FJ
authors.lastname: Zhang
authors.forename: Jun-Qiang
authors.initials: JQ
authors.lastname: Si
authors.forename: Rui-Rui
authors.initials: RR
authors.lastname: Yang
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.forename: Wei-Jian
authors.initials: WJ
authors.lastname: Gao
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects* / Q000502:physiology*; D011817:Rabbits
chemical_list: D002316:Cardiotonic Agents; D000109:Acetylcholine