Inotropy and L-type Ca 2+ current, activated by β 1- and β 2-adrenoceptors, are differently controlled by phosphodiesterases 3 and 4 in rat heart

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Torsten Christ - , Universitätsklinikum Carl Gustav Carus Dresden (Autor:in)
  • Alejandro Galindo-Tovar - , Universitätsklinikum Carl Gustav Carus Dresden (Autor:in)
  • Marcus Thoms - , Universitätsklinikum Carl Gustav Carus Dresden (Autor:in)
  • Ursula Ravens - , Universitätsklinikum Carl Gustav Carus Dresden (Autor:in)
  • Alberto J. Kaumann - , University of Cambridge (Autor:in)

Abstract

Background and purpose: β 1- and β 2- adrenoceptors coexist in rat heart but β 2-adrenoceptor-mediated inotropic effects are hardly detectable, possibly due to phosphodiesterase (PDE) activity. We investigated the influence of the PDE3 inhibitor cilostamide (300 nmol·L -1) and the PDE4 inhibitor rolipram (1 ̄mol·L -1) on the effects of (-)-catecholamines. Experimental approach: Cardiostimulation evoked by (-)-noradrenaline (ICI118551 present) and (-)-adrenaline (CGP20712A present) through β 1- and β 2-adrenoceptors, respectively, was compared on sinoatrial beating rate, left atrial and ventricular contractile force in i/ated tissues from Wistar rats. L-type Ca 2+-current (I Ca-L) was assessed with whole-cell patch clamp. Key results: Rolipram caused sinoatrial tachycardia. Cilostamide and rolipram did not enhance chronotropic potencies of (-)-noradrenaline and (-)-adrenaline. Rolipram but not cilostamide potentiated atrial and ventricular inotropic effects of (-)-noradrenaline. Cilostamide potentiated the ventricular effects of (-)-adrenaline but not of (-)-noradrenaline. Concurrent cilostamide + rolipram uncovered left atrial effects of (-)-adrenaline. Both rolipram and cilostamide augmented the (-)-noradrenaline (1 ̄mol·L -1) evoked increase in I Ca-L. (-)-Adrenaline (10 ̄mol·L -1) increased I Ca-L only in the presence of cilostamide but not rolipram. Conclusions and implications: PDE4 blunts the β 1-adrenoceptor- mediated inotropic effects. PDE4 reduces basal sinoatrial rate in a compartment distinct from compartments controlled by β 1- and β 2-adrenoceptors. PDE3 and PDE4 jointly prevent left atrial β 2-adrenoceptor-mediated inotropy. Both PDE3 and PDE4 reduce I Ca-L responses through β 1-adrenoceptors but the PDE3 component is unrelated to inotropy. PDE3 blunts both ventricular inotropic and I Ca-L responses through β 2-adrenoceptors.

Details

OriginalspracheEnglisch
Seiten (von - bis)62-83
Seitenumfang22
FachzeitschriftBritish journal of pharmacology
Jahrgang156
Ausgabenummer1
PublikationsstatusVeröffentlicht - Jan. 2009
Peer-Review-StatusJa

Externe IDs

PubMed 19133992

Schlagworte

ASJC Scopus Sachgebiete

Schlagwörter

  • β - and β -adrenoceptors, (-)-adrenaline, (-)-noradrenaline, Calcium current, Phosphodiesterases, Rat atrium, Sinoatrial node, Ventricle