Specific β ₂ AR Blocker ICI 118,551 Actively Decreases Contraction Through a G _i -Coupled Form of the β ₂ AR in Myocytes From Failing Human Heart

• Haibin Gong

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

• Hong Sun

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

• Walter J. Koch

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

• Thomas Rau

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

• Thomas Eschenhagen

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

• Ursula Ravens

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

• Jürgen F. Heubach

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

• Dawn L. Adamson

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

• Sian E. Harding

  From the National Heart and Lung Institute, Imperial College School of Medicine, London, UK; Department of Experimental Surgery (W.J.K.), Duke University Medical Center, Durham, NC; Institute of Pharmacology (T.R., T.E.), University of Erlangen, Germany; and Institut fur Pharmakologie und Toxikologie (U.R., J.F.H.), Universitat Carl Gustav Carus, Dresden, Germany.

抄録

Background — We have observed direct (noncatecholamine-blocking) negative inotropic effects of the selective β 2 -adrenoceptor (AR) antagonist ICI 118,551 in myocytes from failing human ventricle. In this study we characterize the effect in parallel in human myocytes and in myocytes from animal models where β 2 ARs or G i proteins are overexpressed. Methods and Results — Enzymatically isolated, superfused ventricular myocytes were exposed to βAR agonists and antagonists/inverse agonists, and contraction amplitude was measured. ICI 118,551 decreased contraction in ventricular myocytes from failing human hearts by 45.3±4.1% (n=20 hearts/31 myocytes, P <0.001) but had little effect in nonfailing hearts (4.9±4%, n=5 myocytes/3 hearts). Effects were significantly larger in patients classified as end-stage. Transgenic mice with high β 2 AR number and increased G i levels had normal basal contractility but showed a similar negative inotropic response to ICI 118,551. Overexpression of human β 2 AR in rabbit myocytes using adenovirus potentiated the negative inotropic effect of ICI 118,551. In human, rabbit, and mouse myocytes, the negative inotropic effects were blocked after treatment of cells with pertussis toxin to inactivate G i , and overexpression of G i α 2 induced the effect de novo in normal rat myocytes. Conclusions — We hypothesize that ICI 118,551 binding directs the β 2 AR to a G i -coupled form and away from the G s -coupled form (ligand-directed trafficking). ICI 118,551 effectively acts as an agonist at the G i -coupled β 2 AR, producing a direct negative inotropic effect. Conditions where β 2 ARs are present and G i is raised (failing human heart, TGβ 2 mouse heart) predispose to the appearance of the negative inotropic effect.

収録刊行物

• Circulation

  Circulation 105 (21), 2497-2503, 2002-05-28

  Ovid Technologies (Wolters Kluwer Health)

キーワード

• Physiology (medical)
• Cardiology and Cardiovascular Medicine

詳細情報

• CRID: 1360011145075165824
• NII論文ID: 30022666763
• DOI: 10.1161/01.cir.0000017187.61348.95
• ISSN: 15244539
• ISSN: 00097322
• Web Site: https://www.ahajournals.org/doi/full/10.1161/01.CIR.0000017187.61348.95
• データソース種別:
  • Crossref
  • CiNii Articles