title: [Effects of overexpression of beta2-adrenoceptor on contraction in cardiac myocytes isolated from failure hearts of rats].
abstract: OBJECTIVE
  To investigate the role of overexpression of beta2-adrenoceptor on contraction in cardiac myocytes isolated from failure hearts of rats and primarily analyses its mechanisms.
  
  
  METHODS
  Primarily cultured cardiac myocytes were infected with adenovirus containing the sequence for human beta2-adrenoceptors. The expression of beta2-adrenoceptors was tested by Western blot. The contraction amplitudes induced by isoprenaline stimulation were measured.
  
  
  RESULTS
  Overexpression of beta2-adrenoceptor increased the content in failure cardiac myocytes. The contraction amplitudes in failure cardiac myocytes were lower than that in the control (P < 0.01). Overexpression of beta2 adrenoceptor improved the contraction of failure cardiac myocytes (P < 0.01, Failure+ Adv.Beta2 group vs. Failure group). Selective beta2-adrenoceptor antagonist ICI 118,551 partially reversed the effects (P < 0.05, Failure+ Adv.beta2 + ICI group vs Failure + Adv.beta2 group), but the contraction amplitudes in this Failure +/- Adv.beta2 + ICI 118,551 group were still higher than that in only heart failure group (P < 0.05). Selective beta1 adrenoceptor antagonist CGP20712A completely inhibited the effects of overexpression of beta2 adrenoceptor on contraction amplitude in failure cardiac myocytes.
  
  
  CONCLUSIONS
  Overexpression of beta2-adrenoceptors improves the contraction of cardiac myocytes isolated from failure hearts of rats. The effect is related to beta1-adrenoceptor.
authors.affiliation: Department of Physiology, Xuzhou Medical College, Xuzhou 221002, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Sun
authors.forename: Ai-min
authors.initials: AM
authors.lastname: Chang
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xin-wei
authors.initials: XW
authors.lastname: Jiang
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D006333:Heart Failure / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction; D032383:Myocytes, Cardiac / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics / Q000378:metabolism*
chemical_list: C553443:ADRB2 protein, human; D000319:Adrenergic beta-Antagonists; D007093:Imidazoles; D018343:Receptors, Adrenergic, beta-2; C049763:CGP 20712A; D007545:Isoproterenol