Effect of oxyphenamone on sodium and calcium channels of guinea pig myocardial cells / 药学学报
Acta Pharmaceutica Sinica
;
(12): 410-414, 2004.
Article
in Chinese
| WPRIM
| ID: wpr-302797
ABSTRACT
<p><b>AIM</b>To investigate the mechanism of the positive inotropic effect of oxyphenamone.</p><p><b>METHODS</b>With the patch clamp technique and whole cell recording, the sodium and L type calcium currents of myocytes isolated from ventricular myocardium of adult guinea pigs were studied.</p><p><b>RESULTS</b>5 - 50 micromol x L(-1)-oxyphenamone not only significantly inhibited Na+ current, but also promoted the process of inactivation and prolonged the recovery time of the inactivation. The action of oxyphenamone on L type calcium channel was dual. The inward calcium current was increased with 2 - 10 micromol x L(-1) oxyphenamone but decreased when the concentration of the drug was elevated to 20 - 50 micromol x L(-1).</p><p><b>CONCLUSION</b>The mechanism of the positive inotropic effect of oxyphenamone is neither due to the activation of sodium channel nor entirely depending upon the activation of L type calcium channel. The effects of inhibiting sodium current and, at a high concentration, blocking L type calcium current suggest that oxyphenamone may have an antiarrhythemia action.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Organic Chemicals
/
Pharmacology
/
Cardiotonic Agents
/
Sodium Channels
/
Patch-Clamp Techniques
/
Calcium Channels, L-Type
/
Cell Biology
/
Myocytes, Cardiac
/
Guinea Pigs
/
Heart Ventricles
Limits:
Animals
Language:
Chinese
Journal:
Acta Pharmaceutica Sinica
Year:
2004
Type:
Article
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