Mediation by nitric oxide of the indirect effects of adenosine on calcium current in rabbit heart pacemaker cells

British Journal of Pharmacology
Y ShimoniW R Giles

Abstract

1. Adenosine (ADO) is a potent negative chronotropic agent in the mammalian myocardium. We have used single myocytes from rabbit sino-atrial node (SAN) to examine whether nitric oxide (NO) is a significant mediator of the effects of ADO on the pacemaker activity, or the underlying Ca2+ and K+ currents. 2. SAN pacemaker cells were isolated from rabbit hearts by enzymatic dispersion, and Ca2+ and K+ currents were recorded by the nystatin-perforated patch voltage clamp method. ADO was applied in the presence of the beta-adrenoceptor agonist, isopremaline (Iso) to mimic the adrenergic tone which the SAN is subjected to in vivo. 3. Control experiments confirmed that isolated SAN cells responded to ADO (10-100 microM) with the expected (i) small increase in background inwardly rectifying K+ current, IK-ADOi and (ii) pronounced decrease in L-type Ca2+ current, ICa-L. These effects were mimicked by a selective A1 purinoceptor agonist, N6-cyclopentyladenosine (CPA, 10 microM); and were inhibited following bath application of the antagonist, DPCPX (10 microM), which selectively blocks A1 purinoceptors. DMPX (10 microM), a blocker of A2 purinoceptor, had no effect on the actions of ADO. 4. A nitric oxide synthase inhibitor, L-NMMA (100 mi...Continue Reading

References

Dec 1, 1992·Trends in Pharmacological Sciences·K A RudolphiB B Fredholm
Jan 1, 1992·Neuron·D S Bredt, S H Snyder
Jun 1, 1992·The American Journal of Medicine·A C RankinB A McGovern
Nov 1, 1991·Pacing and Clinical Electrophysiology : PACE·L Belardinelli, B B Lerman
Jul 1, 1990·Physiological Reviews·R A Olsson, J D Pearson
Jun 1, 1987·The Journal of Physiology·R Fischmeister, H C Hartzell
Aug 1, 1988·The Journal of General Physiology·R Horn, A Marty
Jul 1, 1989·Progress in Cardiovascular Diseases·L BelardinelliR M Berne
Nov 1, 1988·The Journal of Physiology·L BelardinelliA West
Oct 1, 1982·Pflügers Archiv : European journal of physiology·G Isenberg, U Klockner
Jul 1, 1995·The Journal of General Physiology·X HanW R Giles
Mar 1, 1994·Pflügers Archiv : European journal of physiology·R C LeviM P Gallo
Jan 1, 1995·Annual Review of Pharmacology and Toxicology·M E Olah, G L Stiles
Jan 1, 1993·Proceedings of the National Academy of Sciences of the United States of America·J L BalligandT Michel
Aug 18, 1993·Biochimica Et Biophysica Acta·H H SchmidtU Walter
Mar 1, 1995·FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology·L BelardinelliM Srinivas
Apr 15, 1994·The Journal of Physiology·X HanW R Giles
Sep 1, 1994·Cardiovascular Research·G KabellL Belardinelli
May 1, 1993·Cardiovascular Research·J Parratt
Jan 1, 1993·Physiological Reviews·H IrisawaW Giles
Jan 1, 1993·Cardiovascular Research·A Pelleg, L Belardinelli
Jan 1, 1996·Pflügers Archiv : European journal of physiology·A E MartynyukA C Rankin
Dec 1, 1995·British Journal of Pharmacology·H NawrathH Oelert

❮ Previous
Next ❯

Citations

Nov 1, 1983·Comprehensive Psychiatry·D J Safer
Jun 28, 2005·Progress in Biophysics and Molecular Biology·Matteo E MangoniJoël Nargeot
Jun 19, 1997·The American Journal of Cardiology·J C Shryock, L Belardinelli
Oct 19, 2001·British Journal of Pharmacology·P NieriM C Breschi
May 30, 1998·Proceedings of the National Academy of Sciences of the United States of America·X HanR A Kelly
Mar 23, 2010·Journal of Biomedical Science·Yung-Kuo LinShih-Ann Chen
May 23, 2014·The Journal of Sexual Medicine·Linda VignozziMario Maggi
Oct 1, 1998·Journal of Cardiac Failure·M A Arstall, R A Kelly
Dec 19, 2001·Microscopy Research and Technique·W BlochB K Fleischmann
Jul 16, 2008·Physiological Reviews·Matteo E Mangoni, Joël Nargeot

❮ Previous
Next ❯

Related Concepts

Related Feeds

Cardiac Electrophysiology

Cardiac electrophysiology is the study of electrical activities of the heart and includes the assessment, diagnosis, and treatment of cardiac events. Find the latest research on cardiac electrophysiology here.