Effect of moxonidine on arrhythmias induced by coronary artery occlusion and reperfusion.
The aim of the present study was to investigate the influence of moxonidine, a representative of I1-imidazoline-receptor agonist, on arrhythmias induced by myocardial ischemia or reperfusion. Acute myocardial infarction was produced by tightening a previously placed loose silk loop around the coronary artery in conscious rats. Moxonidine (0.01, 0.03, or 0.10 mg/kg i.v., 10 min before coronary ligation) significantly decreased the incidence of ventricular tachycardia during the first 15 min of infarction (70 versus 100% in controls), and the number of animals that survived without developing any arrhythmia was increased (15, 20, and 25%, respectively, versus 0%). Reperfusion-induced arrhythmias were produced by releasing a snare after 6 min of myocardial ischemia in anesthetized, artificially ventilated rats. Reperfusion rapidly induced severe dysrhythmias in all of the control animals. Moxonidine pretreatment (0.03 and 0.10 mg/kg) decreased the incidence of ventricular fibrillation (25 and 30% versus 64%) and increased the number of animals that survived without developing any arrhythmia (20 and 25% versus 0%). We conclude that moxonidine offers significant protection against the development of arrhythmias induced by acute regional myocardial ischemia in conscious rats. Moxonidine pretreatment also provides a beneficial effect during reperfusion-induced arrhythmias that appear after a brief period of myocardial ischemia.
Leprán
I
I
Department of Pharmacology, Albert Szent-Györgyi Medical University, Szeged, Hungary.
Papp
J G
JG
D000704:Analysis of Variance; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000188:drug therapy* / Q000209:etiology; D003331:Coronary Vessels / Q000187:drug effects / Q000601:surgery; D004195:Disease Models, Animal; D006339:Heart Rate / Q000187:drug effects; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D054755:Imidazoline Receptors; D008026:Ligation; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000150:complications / Q000188:drug therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011955:Receptors, Drug / Q000187:drug effects; D013610:Tachycardia / Q000188:drug therapy; D014693:Ventricular Fibrillation / Q000517:prevention & control
D000959:Antihypertensive Agents; D007093:Imidazoles; D054755:Imidazoline Receptors; D011955:Receptors, Drug; C043482:moxonidine