Effect of citalopram on ouabain-induced arrhythmia in isolated guinea-pig atria.
The effect of citalopram (CTP) a selective serotonin reuptake inhibitor agent was studied on ouabain-induced arrhythmia in spontaneously beating isolated guinea-pig atria. CTP (2-32 microg/ml) produced a dose-dependent decrease in the force of contractions (7-62%), and in the rate of contractions (11-72%). Pre-administration of the atria with CTP inhibited the ouabain-induced arrhythmia in isolated atria. Ouabain alone (1.2 microg/ml) produced arrhythmia at 4.5 min, and asystole at 20.7 min. Pretreatment with CTP (8 microg/ml) significantly increased the time of onset of arrhythmia to 9.5 min. In addition CTP prolonged the beating of atria (survival time) to more than 56 min, and inhibited the occurrence of asystole. These findings indicate that CTP produces direct cardiac action, probably due to the inhibition of cardiac Na(+) and Ca(2+) channels. Moreover our results suggest that CTP may reduce the membrane conductance through inhibition of ionic channels which decrease ouabain-induced arrhythmia.
Pousti
Abbas
A
Department of Pharmacology, Tehran University of Medical Sciences, Tehran, Iran. drpousti@yahoo.com
Malihi
Golrokh
G
Naghibi
Bijan
B
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000503:physiopathology*; D015283:Citalopram / Q000009:adverse effects / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D010042:Ouabain; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects / Q000494:pharmacology*
D015283:Citalopram; D010042:Ouabain; D017367:Selective Serotonin Reuptake Inhibitors