![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
CH Follmer, M Aomine, JZ Yeh and DH Singer
Department of Pharmacology, Northwestern University Medical School, Chicago, Illinois.
Sodium current (INa) block by amiodarone (AMI) was investigated in isolated single Purkinje and ventricular myocardial cells using the single suction-pipette voltage-clamp technique. AMI produced marked resting block that was enhanced at low holding potentials, findings consistent with a shift in the steady-state INa availability curve to more negative potentials (-16 +/- 3 mV). Resting block was not associated with any change in the time course of INa decay during a depolarizing clamp step. AMI also produced use-dependent block in conjunction with increases in rate (0.5-5.0 Hz) and pulse duration (2- 200 msec). These changes are consistent with a slowing of the recovery from inactivation of the sodium channel. Brief depolarizing pulses produced little use-dependent block, suggesting that the onset of drug- induced block is slow. Thus, AMI blocks INa and shifts the availability curve in isolated myocytes, both of which contribute to the net tonic block. The results suggest that both rested state and inactivated state sodium channel block are factors in AMI's antiarrhythmic efficacy.
This article has been cited by other articles:
|
|
 |
|
  D. Celestino, E. Medei, S. Moro, M. V. Elizari, and S. Sicouri Acute In Vitro Effects of Dronedarone, an Iodine-Free Derivative, and Amiodarone, on the Rabbit Sinoatrial Node Automaticity: A Comparative Study Journal of Cardiovascular Pharmacology and Therapeutics, September 1, 2007; 12(3): 248 - 257. [Abstract] [PDF]
|
|
|
|
 |
|
 N. Yamashita, T. Kaku, T. Uchino, S. Isomoto, H. Yoshimatsu, and K. Ono Short- and Long-Term Amiodarone Treatments Regulate Cav3.2 Low-Voltage-Activated T-type Ca2+ Channel through Distinct Mechanisms Mol. Pharmacol., May 1, 2006; 69(5): 1684 - 1691. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Macianskiene, S. Viappiani, K. R. Sipido, and K. Mubagwa Slowing of the Inactivation of Cardiac Voltage-Dependent Sodium Channels by the Amiodarone Derivative 2-Methyl-3-(3,5-diiodo-4-carboxymethoxybenzyl)benzofuran (KB130015) J. Pharmacol. Exp. Ther., January 1, 2003; 304(1): 130 - 138. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Omichi, S. Zhou, M.-H. Lee, A. Naik, C.-M. Chang, A. Garfinkel, J. N. Weiss, S.-F. Lin, H. S. Karagueuzian, and P.-S. Chen Effects of amiodarone on wave front dynamics during ventricular fibrillation in isolated swine right ventricle Am J Physiol Heart Circ Physiol, March 1, 2002; 282(3): H1063 - H1070. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. G. Cosio and E. Delpon New Antiarrhythmic Drugs for Atrial Flutter and Atrial Fibrillation: A Conceptual Breakthrough at Last? Circulation, January 22, 2002; 105(3): 276 - 278. [Full Text] [PDF]
|
|
|
|
|
|
F. Aimond, L. Beck, P. Gautier, O. K. Chérif, J.-M. Davy, P. Lorente, D. Nisato, and G. Vassort Cellular and In Vivo Electrophysiological Effects of Dronedarone in Normal and Postmyocardial Infarcted Rats J. Pharmacol. Exp. Ther., January 1, 2000; 292(1): 415 - 424. [Abstract] [Full Text]
|
|
|
|
 |
|
 J. Merot, F. Charpentier, J.-M. Poirier, G. Coutris, and J. Weissenburger Effects of chronic treatment by amiodarone on transmural heterogeneity of canine ventricular repolarization in vivo: interactions with acute sotalol Cardiovasc Res, November 1, 1999; 44(2): 303 - 314. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. F. Bosch, G.-R. Li, R. Gaspo, and S. Nattel Electrophysiologic Effects of Chronic Amiodarone Therapy and Hypothyroidism, Alone and in Combination, on Guinea Pig Ventricular Myocytes J. Pharmacol. Exp. Ther., April 1, 1999; 289(1): 156 - 165. [Abstract] [Full Text]
|
|
|
|
|
|
Fuhua Chen, S. Naim, W. F. Friedman, T. S. Klitzner, and G. T. Wetzel Age-Dependent Changes in the Effects of Amiodarone on Rabbit Cardiac Myocyte Contractions Journal of Cardiovascular Pharmacology and Therapeutics, January 1, 1999; 4(1): 23 - 32. [Abstract] [PDF]
|
|
|
|
|
|
D. F. Gray, A. S. Mihailidou, P. S. Hansen, K. A. Buhagiar, N. L. Bewick, H. H. Rasmussen, and D. W. Whalley Amiodarone Inhibits the Na+-K+ Pump in Rabbit Cardiac Myocytes after Acute and Chronic Treatment J. Pharmacol. Exp. Ther., January 1, 1998; 284(1): 75 - 82. [Abstract] [Full Text]
|
|
|
|
|
|
I. Kodama, K. Kamiya, and J. Toyama Cellular electropharmacology of amiodarone Cardiovasc Res, July 1, 1997; 35(1): 13 - 29. [Full Text] [PDF]
|
|
 |
 |
 |
|
 |
 |
 |
