Mast cell degranulation - a mechanism for the anti-arrhythmic effect of endothelin-1?

S.K. Walsh, K.A. Kane, C.L. Wainwright

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8 Citations (Scopus)

Abstract

The aim of this study was to investigate whether the previously reported anti-arrhythmic effect of endothelin-1 (ET-1) is mediated by degranulation of cardiac mast cells prior to myocardial ischaemia. Male Sprague-Dawley rats received either ET-1 (1.6 nmol·kg−1) in the presence or absence of disodium cromoglycate (DSCG; 20 mg·kg−1·h−1) prior to coronary artery occlusion (CAO). In separate experiments rats were given compound 48/80 (50 µg·kg−1) to compare the effects of ET-1 with those of a known mast cell degranulator. Ischaemia-induced ventricular arrhythmias were detected through continuous monitoring of a lead I electrocardiogram. After 30 min of CAO, the hearts were removed and mast cell degranulation determined by histological analysis. A parallel series of sham groups were performed to determine the direct effects of ET-1 and compound 48/80 on mast cell degranulation in the absence of ischaemia. ET-1 and compound 48/80 both exerted profound anti-arrhythmic effects, significantly reducing the total number of ventricular ectopic beats (P < 0.001) and the incidence of ventricular fibrillation (P < 0.05). These anti-arrhythmic effects were abolished by concomitant DSCG infusion prior to CAO. In sham animals ET-1 and compound 48/80 both induced mast cell degranulation (P < 0.001), an effect which was abolished by DSCG, confirming their ability to induce degranulation of mast cells. These results demonstrate for the first time that when given prior to ischaemia ET-1 mediates its anti-arrhythmic effects, at least in part, via cardiac mast cell degranulation.
Original languageEnglish
Pages (from-to)716-723
Number of pages7
JournalBritish Journal of Pharmacology
Volume157
Issue number5
DOIs
Publication statusPublished - Jul 2009

Keywords

  • mast cell degranulation
  • endothelin-1
  • myocardial ischaemia
  • arrhythmias

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