| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Biophysical Journal 70: 1700-1708 (1996)
© 1996 the Biophysical Society
Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA.
ABSTRACT
Lidocaine is a widely used local anesthetic and antiarrhythmic drug that is believed to exert its clinically important action by blocking voltage-gated Na+ channels. Studies of Na+ channels from different species and tissues and the complexity of the drug-channel interaction create difficulty in understanding whether there are Na+ channel isoform specific differences in the affinity for lidocaine. Clinical usage suggests that lidocaine selectively targets cardiac Na+ channels because it is effective for the treatment of arrhythmias with few side effects on muscle or neuronal channels except at higher concentrations. One possibility for this selectivity is an intrinsically higher drug-binding affinity of the cardiac isoform. Alternatively, lidocaine may appear cardioselective because of preferential interactions with the inactivated state of the Na+ channel, which is occupied much longer in cardiac cells. Recombinant skeletal muscle (hSkM1) and cardiac sodium channels (hH1) were studied under identical conditions, with a whole-cell voltage clamp used to distinguish the mechanisms of lidocaine block. Tonic block at high concentrations of lidocaine (0.1 mM) was greater in hH1 than in hSkM1. This was also true for use-dependent block, for which 25-microM lidocaine produced an inhibition in hH1 equivalent to 0.1 mM in the skeletal muscle isoform. Pulse protocols optimized to explore inactivated-state block revealed that hSkM1 was five to eight times less sensitive to block by lidocaine than was hH1. The results also indicate that relatively more open-state block occurs in hSkM1. Thus, the cardiac sodium channel is intrinsically more sensitive to inhibition by lidocaine.
This article has been cited by other articles:
![]() |
J.-F. Desaphy, A. D. E. Luca, M. P. Didonna, A. L. George Jr, and D. C. Camerino Different flecainide sensitivity of hNav1.4 channels and myotonic mutants explained by state-dependent block J. Physiol., January 15, 2004; 554(2): 321 - 334. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. De Luca, S. Talon, M. De Bellis, J.-F. Desaphy, G. Lentini, F. Corbo, A. Scilimati, C. Franchini, V. Tortorella, and D. C. Camerino Optimal Requirements for High Affinity and Use-Dependent Block of Skeletal Muscle Sodium Channel by N-Benzyl Analogs of Tocainide-Like Compounds Mol. Pharmacol., October 1, 2003; 64(4): 932 - 945. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Hilber, W. Sandtner, O. Kudlacek, B. Schreiner, I. Glaaser, W. Schutz, H. A. Fozzard, S. C. Dudley, and H. Todt Interaction between Fast and Ultra-slow Inactivation in the Voltage-gated Sodium Channel. DOES THE INACTIVATION GATE STABILIZE THE CHANNEL STRUCTURE? J. Biol. Chem., September 27, 2002; 277(40): 37105 - 37115. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. G. Mujtaba, S.-Y. Wang, and G. K. Wang Prenylamine Block of Nav1.5 Channel is Mediated via a Receptor Distinct from That of Local Anesthetics Mol. Pharmacol., August 1, 2002; 62(2): 415 - 422. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Li, I. L. Ennis, G. F. Tomaselli, and E. Marban Structural Basis of Differences in Isoform-Specific Gating and Lidocaine Block between Cardiac and Skeletal Muscle Sodium Channels Mol. Pharmacol., January 1, 2002; 61(1): 136 - 141. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-F. Desaphy, A. De Luca, P. Tortorella, D. De Vito, A. L. George Jr., and D. Conte Camerino Gating of myotonic Na channel mutants defines the response to mexiletine and a potent derivative Neurology, November 27, 2001; 57(10): 1849 - 1857. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. De Luca, F. Natuzzi, J.-F. Desaphy, G. Loni, G. Lentini, C. Franchini, V. Tortorella, and D. C. Camerino Molecular Determinants of Mexiletine Structure for Potent and Use-Dependent Block of Skeletal Muscle Sodium Channels Mol. Pharmacol., February 1, 2000; 57(2): 268 - 277. [Abstract] [Full Text] |
||||
![]() |
T. Weiser, Y. Qu, W. A. Catterall, and T. Scheuer Differential Interaction of R-Mexiletine with the Local Anesthetic Receptor Site on Brain and Heart Sodium Channel alpha -Subunits Mol. Pharmacol., December 1, 1999; 56(6): 1238 - 1244. [Abstract] [Full Text] |
||||
![]() |
R. A. Li, R. G. Tsushima, K. Himmeldirk, D. S. Dime, and P. H. Backx Local Anesthetic Anchoring to Cardiac Sodium Channels : Implications Into Tissue-Selective Drug Targeting Circ. Res., July 9, 1999; 85(1): 88 - 98. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. R. Balser Structure and function of the cardiac sodium channels Cardiovasc Res, May 1, 1999; 42(2): 327 - 328. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C Makielski, J. Limberis, Z. Fan, and J. W Kyle Intrinsic lidocaine affinity for Na channels expressed in Xenopus oocytes depends on {alpha} (hH1 vs. rSkM1) and {beta}1 subunits Cardiovasc Res, May 1, 1999; 42(2): 503 - 509. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-F. Desaphy, A. De Luca, S. Pierno, P. Imbrici, and D. C. Camerino Partial Recovery of Skeletal Muscle Sodium Channel Properties in Aged Rats Chronically Treated with Growth Hormone or the GH-Secretagogue Hexarelin J. Pharmacol. Exp. Ther., August 1, 1998; 286(2): 903 - 912. [Abstract] [Full Text] |
||||
![]() |
R. L. Sah, R. G. Tsushima, and P. H. Backx Effects of local anesthetics on Na+ channels containing the equine hyperkalemic periodic paralysis mutation Am J Physiol Cell Physiol, August 1, 1998; 275(2): C389 - C400. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Liu, R. B. Melchert, and R. H. Kennedy Inhibition of L-Type Ca2+ Channel Current in Rat Ventricular Myocytes by Terfenadine Circ. Res., August 19, 1997; 81(2): 202 - 210. [Abstract] [Full Text] |
||||
![]() |
A. De Luca, S. Pierno, F. Natuzzi, C. Franchini, A. Duranti, G. Lentini, V. Tortorella, H. Jockusch, and D. C. Camerino Evaluation of the Antimyotonic Activity of Mexiletine and Some New Analogs on Sodium Currents of Single Muscle Fibers and on the Abnormal Excitability of the Myotonic ADR Mouse J. Pharmacol. Exp. Ther., July 1, 1997; 282(1): 93 - 100. [Abstract] [Full Text] |
||||
![]() |
D. W. Wang, K. Yazawa, A. L. George Jr., and P. B. Bennett Characterization of human cardiac Na+ channel mutations in the congenital long QT syndrome PNAS, November 12, 1996; 93(23): 13200 - 13205. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |