Phosphodiesterase PDE3, but not PDE4, reduces β1- and β2-adrenoceptor-mediated inotropic and lusitropic effects in failing ventricle from metoprolol-treated patients
Molenaar, Peter, Christ, Torsten, Hussain, Rizwan I., Engel, Andreas, Berk, Emanuel, Gillette, Katherine T., Chen, Lu, Galindo-Tovar, Alejandro, Ravens, Ursula, Krobert, Kurt A., Levy, Finn Olav, & Kaumann, Alberto J. (2013) Phosphodiesterase PDE3, but not PDE4, reduces β1- and β2-adrenoceptor-mediated inotropic and lusitropic effects in failing ventricle from metoprolol-treated patients. British Journal of Pharmacology, 169(3), pp. 528-538.
Background and purpose
Phosphodiesterases PDE3 and/or PDE4 control ventricular effects of catecholamines in several species but their relative effects in failing human ventricle are unknown. We investigated whether the PDE3-selective inhibitor cilostamide (0.3-1μM) or PDE4 inhibitor rolipram (1-10μM) modified the positive inotropic and lusitropic effects of catecholamines in human failing myocardium.
Right and left ventricular trabeculae from freshly explanted hearts of 5 non-β-blocker-treated and 15 metoprolol-treated patients with terminal heart failure were paced to contract at 1Hz. The effects of (-)-noradrenaline, mediated through β1-adrenoceptors (β2-adrenoceptors blocked with ICI118551), and (-)-adrenaline, mediated through β2-adrenoceptors (β1-adrenoceptors blocked with CGP20712A), were assessed in the absence and presence of PDE inhibitors. Catecholamine potencies were estimated from –logEC50s.
Cilostamide did not significantly potentiate the inotropic effects of the catecholamines in non-β-blocker-treated patients. Cilostamide caused greater potentiation (P=0.037) of the positive inotropic effects of (-)-adrenaline (0.78±0.12 log units) than (-)-noradrenaline (0.47±0.12 log units) in metoprolol-treated patients. Lusitropic effects of the catecholamines were also potentiated by cilostamide. Rolipram did not affect the inotropic and lusitropic potencies of (-)-noradrenaline or (-)-adrenaline on right and left ventricular trabeculae from metoprolol-treated patients.
Conclusions and implications
Metoprolol induces a control by PDE3 of ventricular effects mediated through both β1- and β2-adrenoceptors, thereby further reducing sympathetic cardiostimulation in patients with terminal heart failure. Concurrent therapy with a PDE3 blocker and metoprolol could conceivably facilitate cardiostimulation evoked by adrenaline through β2-adrenoceptors. PDE4 does not appear to reduce inotropic and lusitropic effects of catecholamines in failing human ventricle.
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|Item Type:||Journal Article|
|Keywords:||Human heart failure , β1-and β2-adrenoceptors , phosphodiesterases 3 and 4, noradrenaline and adrenaline , inotropism and lusitropism , metoprolol|
|Subjects:||Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > CARDIOVASCULAR MEDICINE AND HAEMATOLOGY (110200) > Cardiology (incl. Cardiovascular Diseases) (110201)
Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > PHARMACOLOGY AND PHARMACEUTICAL SCIENCES (111500) > Basic Pharmacology (111501)
|Divisions:||Current > Schools > School of Biomedical Sciences
Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
|Copyright Owner:||Copyright 2013 The Authors and The British Pharmacological Society|
|Deposited On:||12 Mar 2014 05:25|
|Last Modified:||30 Jun 2014 14:11|
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