title: [Effects of cardioplegia with tetrodotoxin on intracellular sodium overload of ischemia/reperfusion cardiomyocytes].
abstract: OBJECTIVE
  To investigate the effects of polarizing cardioplegia solution with sodium channel inhibitor tetrodotoxin (TTX) on intracellular free Na+ concentration ([Na+]i) in isolated cardiomyocytes of rat.
  
  
  METHODS
  Ventricular myocytes with beating were isolated from adult rat hearts by enzymatic dissociation, randomly created in group base, group STH2 (contrast group of ischemia/reperfusion) and group TFX (treated group). Both Group STH2 and group TTX were arrested by St. Thomas No. 2 cardioplegia solution and TTX cardioplegia solution respectively, the arrest/re-beating cell model imitating MIRI being established, and imaged by laser scanning confocal microscopy (LSCM) for measuring [Na+]i of cardiomyocytes in different period. The morphology of cardiomyocytes was observed under the inverted microscope.
  
  
  RESULTS
  [Na+]i of cardiomyocytes in both group TTX and group STH2 after re-beating was higher than that in group base (P < 0.01), and [Na+]i in group TTX was lower than that in group STH2 (P < 0.01). During arrest, the elevation of [Na+]i in group TTX was lower than that in group STH2. During arrest, the elevation of [Na+]i in group TTX was lower than that in group STH2. Morphologically, after re-beating, the ratio of active cardiomyocytes with normal form in group TTX was higher than that in group STH2 (P < 0.01).
  
  
  CONCLUSIONS
  Contrast depolarized cardioplegia solution, TTX cardioplegia solution could alleviate ischemia reperfusion injury and intracellular Na+ overload of cardiomyocytes.
authors.affiliation: Department of Cardiothoracic Surgery, the Second People's Hospital of Yibin City, Sichuan 644000, China.
authors.forename: Chao-Kun
authors.initials: CK
authors.lastname: Yang
authors.forename: Shuang-Qiang
authors.initials: SQ
authors.lastname: Yang
authors.forename: Song-Tao
authors.initials: ST
authors.lastname: Tan
mesh_terms: D000818:Animals; D002314:Cardioplegic Solutions / Q000494:pharmacology; D015687:Cell Hypoxia; D002478:Cells, Cultured; D005260:Female; D006324:Heart Arrest, Induced; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D026941:Sodium Channel Blockers / Q000494:pharmacology*; D013779:Tetrodotoxin / Q000494:pharmacology*
chemical_list: D002314:Cardioplegic Solutions; D026941:Sodium Channel Blockers; D013779:Tetrodotoxin; D012964:Sodium