Please use this identifier to cite or link to this item:
https://hdl.handle.net/2440/40231
Citations | ||
Scopus | Web of ScienceĀ® | Altmetric |
---|---|---|
?
|
?
|
Type: | Journal article |
Title: | Block of Na+ and K+ currents in rat ventricular myocytes by quinacainol and quinidine |
Author: | Pugsley, M. Walker, M. Saint, D. |
Citation: | Clinical and Experimental Pharmacology and Physiology, 2005; 32(1-2):60-65 |
Publisher: | Blackwell Publishing Asia |
Issue Date: | 2005 |
ISSN: | 0305-1870 1440-1681 |
Statement of Responsibility: | Michael K Pugsley, Michael JA Walker, David A Saint |
Abstract: | 1. The electrophysiological actions of quinacainol were investigated on sodium (I(Na)), transient outward (i(to)) and sustained-outward plateau (iKsus) potassium currents in rat isolated cardiac myocytes using the whole-cell patch-clamp technique and compared with quinidine. 2. Quinacainol blocked sodium currents in a concentration-dependent manner and with a potency similar to that of quinidine (mean (+/-SEM) EC50 50+/-12 vs 95+/-25 micromol/L for quinidine and quinacainol, respectively). However, quinacainol had a considerably prolonged onset and recovery from block compared with quinidine. 3. Neither quinacainol nor quinidine significantly changed the steady state voltage dependence of activation of sodium currents. Quinidine produced a hyperpolarizing shift in the voltage dependence for sodium current inactivation, but no such shift was observed with quinacainol at doses that produced a substantial current block. 4. Although quinacainol did not effectively block voltage-dependent potassium currents, even at concentrations as high as 1.5 mmol/L, quinidine, at a half-maximal sodium channel-blocking concentration, reduced peak i(to) current amplitude, increased the rate of inactivation of i(to) and blocked iKsus. 5. These results indicate that quinacainol, a quinidine analogue, blocks sodium currents in cardiac myocytes with little effect on i(to) or iKsus potassium currents, which suggests that quinacainol may be exerting class 1c anti-arrhythmic actions. |
Keywords: | Heart Ventricles Myocytes, Cardiac Animals Rats Rats, Wistar Quinidine Quinolines Potassium Channels Sodium Channels Anti-Arrhythmia Agents Potassium Channel Blockers Sodium Channel Blockers Solutions Electrophysiology Membrane Potentials Dose-Response Relationship, Drug Male In Vitro Techniques |
Description: | The definitive version is available at www.blackwell-synergy.com |
DOI: | 10.1111/j.1440-1681.2005.04149.x |
Published version: | http://dx.doi.org/10.1111/j.1440-1681.2005.04149.x |
Appears in Collections: | Aurora harvest Molecular and Biomedical Science publications |
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.