Endothelin receptors in the brain modulate autonomic responses and arrhythmogenesis during acute myocardial infarction in rats

Publication date: Available online 14 November 2019Source: Life SciencesAuthor(s): Panagiotis Lekkas, Marianthi Kontonika, Evgenia S. Georgiou, Vassileios La Rocca, Eleni-Taxiarchia Mouchtouri, Iordanis Mourouzis, Constantinos Pantos, Theofilos M. KolettisAbstractAimsEndothelin has been implicated in various processes in the brain, including the modulation of sympathetic responses. The present study examined the pathophysiologic role of brain endothelin-receptors in the setting of acute myocardial infarction, characterized by high incidence of ventricular tachyarrhythmias.Main methodsWe investigated the effects of intracerebroventricular administration of antagonists of endothelin-receptors ETA, ETB, or both, during a 24 h-observation period post-coronary ligation in (n = 70) rats. Continuous recording was performed via implanted telemetry transmitters, followed by arrhythmia-analysis and calculation of autonomic indices derived from heart rate variability. The regional myocardial electrophysiologic properties were assessed by monophasic action potentials and multi-electrode recordings.Key findingsSympathetic-activity was decreased and vagal-activity was enhanced after intracerebroventricular ETA-receptor blockade, thus attenuating regional myocardial repolarization inhomogeneity. As a result, the incidence of ventricular tachyarrhythmias was markedly lower in this group. Such effects were also observed after intracerebroventricular blockade of ETB-, or both, ETA- and E...
Source: Life Sciences - Category: Biology Source Type: research