title: Effects of experimental diabetes on endothelin-induced ventricular arrhythmias in dogs.
abstract: Endothelin-1 (ET-1) is known to have a direct arrhythmogenic effect in the mammalian heart. Diabetes mellitus is accompanied by a series of endothelial and cardiac disfunctions; however, little is known about ET-1-induced direct arrhythmias in diabetes mellitus. Therefore, we infused ET-1 (33 pmol/min) into the left anterior descending coronary artery of 28 mongrel dogs, and measured basic hemodynamic parameters, coronary flow and an electrocardiogram. Diabetes mellitus was induced by alloxan (Group 4) and experiments were carried out 8 weeks later. Metabolically healthy dogs served as controls (Group 2). In a further control group, local hyperglycemia was induced by intracoronary glucose infusion (Group 3). ET-1 infusion induced prolongation of the QT-time and frequency-adjusted QT-time in all groups. Other electrophysiological parameters were comparable between the groups. This was followed by the occurence of ventricular premature beats, coupled extra-beats and later sustained ventricular tachycardia. Most of the experiments were terminated by ventricular fibrillation. The onset of arrhythmias was shorter in diabetic dogs as compared with control and locally hyperglycemic animals (18 +/- 8 minutes versus 24 +/- 8 minutes and 30 +/- 28 minutes, P < 0.05). However, there was no difference in the number of ventricular fibrillations, and the total elapsed time until the termination of the experiments. Therefore, the diabetic heart seems to be more prone to ET-1-induced arrhythmias and this is probably not a result of locally high glucose concentrations.
authors.affiliation: Gottsegen National Institute of Cardiology, Budapest, Hungary. posai@kardio.hu
authors.forename: Ildikó
authors.initials: I
authors.lastname: Pósa
authors.forename: Ferenc
authors.initials: F
authors.lastname: Horkay
authors.forename: Leila
authors.initials: L
authors.lastname: Seres
authors.forename: Réka
authors.initials: R
authors.lastname: Skoumal
authors.forename: Timea
authors.initials: T
authors.lastname: Kováts
authors.forename: Eva
authors.initials: E
authors.lastname: Balogh
authors.forename: Rudolf
authors.initials: R
authors.lastname: de Châtel
authors.forename: Miklós
authors.initials: M
authors.lastname: Tóth
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Kocsis
mesh_terms: D000818:Animals; D001794:Blood Pressure; D003326:Coronary Circulation; D003921:Diabetes Mellitus, Experimental / Q000150:complications* / Q000503:physiopathology; D004285:Dogs; D004562:Electrocardiography; D019332:Endothelin-1 / Q000008:administration & dosage; D005947:Glucose / Q000008:administration & dosage; D006339:Heart Rate; D006439:Hemodynamics; D007263:Infusions, Parenteral; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000139:chemically induced / Q000209:etiology* / Q000503:physiopathology; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000139:chemically induced / Q000209:etiology* / Q000503:physiopathology; D018879:Ventricular Premature Complexes / Q000139:chemically induced / Q000209:etiology* / Q000503:physiopathology
chemical_list: D019332:Endothelin-1; D005947:Glucose