title: Ketanserin inhibits digoxin-induced arrhythmias in the anaesthetized guinea-pig.
abstract: Digoxin inhibits the membrane-bound ATPase enzyme, resulting in a rise in intracellular sodium and activated outward potassium current, predisposing to arrhythmias. In this study, the effect of ketanserin, thought to block outward potassium currents, was investigated on digoxin-induced arrhythmias. Twenty-four guinea-pigs were studied in four groups (control, ketanserin 0.5 mg/kg, ketanserin 1 mg kg, ketanserin 2 mg/kg). Under pentobarbital anaesthesia (40 mg/kg), 15 min after injection of saline or ketanserin, digoxin (0.6 mg/kg) was administered through the jugular vein. Carotid artery blood pressure and electrocardiogram (ECG) were recorded. The time for the onset of the first arrhythmia and incidence of ventricular tachycardia (VT), ventricular fibrillation (VF), and premature ventricular contraction (PVC) were determined. Arrhythmias were scored according to the MacLeod scale. Ketanserin produced minor haemodynamic effects and lacked, by itself, arrhythmogenic effects at the doses studied. However, it increased the time for the onset of the first digoxin-induced arrhythmia and decreased the incidence of VT, VF and PVC. We conclude that ketanserin inhibits digoxin-induced arrhythmias in guinea-pigs.
authors.affiliation: Department of Pharmacology, Karadeniz Technical University Medical School, Trabzon, Turkey.
authors.forename: N I
authors.initials: NI
authors.lastname: Kalyoncu
authors.forename: R
authors.initials: R
authors.lastname: Ozyavuz
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000517:prevention & control*; D001794:Blood Pressure / Q000187:drug effects*; D004077:Digoxin / Q000037:antagonists & inhibitors*; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000187:drug effects; D004791:Enzyme Inhibitors; D005260:Female; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects; D007275:Injections, Intravenous; D007650:Ketanserin / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male
chemical_list: D000959:Antihypertensive Agents; D004791:Enzyme Inhibitors; D004077:Digoxin; D007650:Ketanserin