Intracerebroventricular endothelin receptor-A blockade in rats decreases phase-II ventricular tachyarrhythmias during acute myocardial infarction

Physiol Res. 2019 Oct 25;68(5):867-871. doi: 10.33549/physiolres.934135. Epub 2019 Aug 19.

Abstract

Endothelin alters central sympathetic responses, but the resultant effects on arrhythmogenesis are unknown. We examined ventricular tachyarrhythmias after endothelin receptor-A blockade in the brain of Wistar rats with acute myocardial infarction. For this aim, BQ-123 (n=6) or phosphate-buffered saline (n=6) were injected intracerebroventricularly. After 10 min, the left coronary artery was ligated, followed by implantation of telemetry transmitters. Electrocardiography and voluntary activity (as a surrogate of acute left ventricular failure) were continuously monitored for 24 h. Infarct-size was similar in the two groups. There were fewer episodes of ventricular tachyarrhythmias of shorter average duration in treated rats, leading to markedly shorter total duration (12.3+/-8.9 s), when compared to controls (546.2+/-130.3 s). Voluntary activity increased in treated rats during the last hours of recording, but bradyarrhythmic episodes were comparable between the two groups. Endothelin receptor-A blockade in the brain of rats decreases the incidence of ventricular tachyarrhythmias post-ligation, without affecting bradyarrhythmic episodes. These findings call for further research on the pathophysiologic role of endothelin during acute myocardial infarction.

MeSH terms

  • Animals
  • Cerebral Ventricles / drug effects*
  • Cerebral Ventricles / metabolism
  • Cerebral Ventricles / physiopathology
  • Disease Models, Animal
  • Endothelin A Receptor Antagonists / administration & dosage*
  • Injections, Intraventricular
  • Myocardial Infarction / complications
  • Myocardial Infarction / drug therapy*
  • Myocardial Infarction / metabolism
  • Myocardial Infarction / physiopathology
  • Peptides, Cyclic / administration & dosage*
  • Rats, Wistar
  • Receptor, Endothelin A / drug effects*
  • Receptor, Endothelin A / metabolism
  • Tachycardia, Ventricular / etiology
  • Tachycardia, Ventricular / metabolism
  • Tachycardia, Ventricular / physiopathology
  • Tachycardia, Ventricular / prevention & control*
  • Ventricular Premature Complexes / etiology
  • Ventricular Premature Complexes / metabolism
  • Ventricular Premature Complexes / physiopathology
  • Ventricular Premature Complexes / prevention & control*

Substances

  • Endothelin A Receptor Antagonists
  • Peptides, Cyclic
  • Receptor, Endothelin A
  • cyclo(Trp-Asp-Pro-Val-Leu)