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Further evidence for the role of gap junctions in the delayed antiarrhythmic effect of cardiac pacing
- Source :
- Canadian journal of physiology and pharmacology. 93(7)
- Publication Year :
- 2015
-
Abstract
- The objective of this study was to provide evidence that gap junctions are involved in the delayed antiarrhythmic effect of cardiac pacing. Twenty-four dogs were paced through the right ventricle (4 × 5 min, rate of 240 beats/min) 24 h prior to a 25 min occlusion of the left anterior descending coronary artery. Some of these paced dogs were infused with 50 (n = 7) or 100 μmol/L (n = 7) of the gap junction uncoupler carbenoxolone (CBX), prior to and during the occlusion. Ten sham-paced dogs, subjected only to occlusion, served as the controls. Cardiac pacing markedly reduced the number of ectopic beats and episodes of ventricular tachycardia (VT), as well the incidence of VT and ventricular fibrillation during occlusion. The changes in severity of ischaemia and tissue electrical resistance were also less marked compared with the unpaced controls. Pacing also preserved the permeability of gap junctions, the phosphorylation of connexin43, and the structural integrity of the intercalated discs. The closing of gap junctions with CBX prior to and during ischaemia markedly attenuated or even abolished these protective effects of pacing. Conclusion: Our results support the previous findings that gap junctions play a role in the delayed antiarrhythmic effect of cardiac pacing.
- Subjects :
- Male
medicine.medical_specialty
Time Factors
Physiology
Carbenoxolone
Ischemia
Anterior Descending Coronary Artery
Ventricular tachycardia
Dogs
Physiology (medical)
Internal medicine
Occlusion
medicine
Animals
Pharmacology
business.industry
Gap junction
Cardiac Pacing, Artificial
Gap Junctions
Arrhythmias, Cardiac
General Medicine
medicine.disease
Disease Models, Animal
medicine.anatomical_structure
Ventricle
Anesthesia
Ventricular fibrillation
cardiovascular system
Cardiology
Female
business
medicine.drug
Subjects
Details
- ISSN :
- 12057541
- Volume :
- 93
- Issue :
- 7
- Database :
- OpenAIRE
- Journal :
- Canadian journal of physiology and pharmacology
- Accession number :
- edsair.doi.dedup.....bf880280778851e8a6e8d8e233984b92