Connexin-43 Redistribution and Gap Junction Activation During Forced Restraint Protects Against Sudden Arrhythmic Death in Rats

• Unuma Kana

  Department of Forensic Medicine, Graduate School of Medicine, University of Tokyo Research Fellow of the Japan Society for the Promotion of Science (JSPS)

• Shintani-Ishida Kaori

  Department of Forensic Medicine, Graduate School of Medicine, University of Tokyo

• Tsushima Kensuke

  Department of Cardiovascular Medicine, University of Tokyo Hospital

• Shimosawa Tatsuo

  Department of Clinical Laboratory, Faculty of Medicine, University of Tokyo

• Ueyama Takashi

  Departments of Anatomy and Cell Biology, Wakayama Medical University

• Kuwahara Masayoshi

  Department of Comparative Pathophysiology, Graduate School of Agricultural and Life Sciences, University of Tokyo

• Yoshida Ken-ichi

  Department of Forensic Medicine, Graduate School of Medicine, University of Tokyo

Abstract

Background: Connexin-43 (Cx43) expression is reduced or redistributed in heart disease. Restraint or other emotional stressors might cause sudden death in persons with such diseases, but the mechanism of death and its connection to Cx43 during restraint remain unknown. Whether Cx43 distribution or gap junction (GJ) function during restraint is involved in sudden arrhythmic death in rats is addressed in this study. Methods and Results: Male Sprague - Dawley rats underwent immobilization (IMO), and individual electrocardiographic responses were monitored by telemetry. Heart sections were used to examine ventricular Cx43 distribution, and GJ intercellular communication (GJIC) activity was assessed using a dye-transfer assay. IMO induced the translocation of Cx43 into to the GJ-rich fraction, with a peak at 60 min. During IMO, Cx43 immunofluorescence was enhanced at intercalated discs, in association with GJIC activation, and premature ventricular contractions (PVCs) increased. In the presence of the GJ inhibitor, carbenoxolone (0.25 mg·kg^-1·h^-1), IMO induced lethal ventricular tachycardia or fibrillation in 21.7% of rats, in association with QRS prolongation and increased PVCs. Conclusions: IMO causes Cx43 translocation to intercalated discs, thereby reducing vulnerability to lethal arrhythmias via enhancing GJ coupling.  (Circ J 2010; 74: 1087 - 1095)<br>

Journal

• Circulation Journal

  Circulation Journal 74 (6), 1087-1095, 2010

  The Japanese Circulation Society

Keywords

• Arrhythmia
• Connexin-43
• Emotional stress
• Gap junction
• Sudden death

Details

• CRID: 1390282680082370176
• NII Article ID: 10026474454
• NII Book ID: AA11591968
• DOI: 10.1253/circj.cj-09-1019
• ISSN: 13474820
• ISSN: 13469843
• Web Site: http://www.jstage.jst.go.jp/article/circj/74/6/74_CJ-09-1019/_pdf
• Web Site: https://search.jamas.or.jp/link/ui/2010310536
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed