title: [The effect of hypoxia-early reoxygenation on persistent sodium current in single ventricular myocytes of guinea pig].
abstract: OBJECTIVE
  To investigate the effect of hypoxia/early reoxygenation on persistent sodium current (I(Na.P)) in single ventricular myocytes of guinea pig and discuss its role and significance during this pathological condition.
  
  
  METHODS
  The whole cell patch clamp technology was used to record this current and study its change under the condition of hypoxia/reoxygenation model.
  
  
  RESULTS
  (1) With 0.5 Hz, 1 Hz and 2 Hz pulse frequency, the current density gap between the first and the eighth pulse of I(Na.P) was (0.021 +/- 0.014) pA/ pF, (0.097 +/- 0.014) pA/pF and (0.133 +/- 0.024) pA/pF (P < 0.01) respectively. (2) Depolarization with membrane holding potential of -150 - -80 mV respectively, I(Na.P) density attenuated gradually. (3) The amplitude of I(Na.P) was increased consistently with the prolongation of hypoxia time during hypoxia. (4) I(Na.P) was (0.500 +/- 0.125) pA/pF, (1.294 +/- 0.321) pA/pF and (0.988 +/- 0.189) pA/pF (P < 0.01, vs normoxia, respectively) during normoxia, hypoxia after 15 min and reoxygenation after 5 min, respectively.
  
  
  CONCLUSIONS
  These results indicate that I(Na.P) has great significance in arrhythmogenesis and calcium-overload, which causes the following postischemia and post hypoxia myocardial damage.
authors.affiliation: Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and Technology, Wuhan 430080, China.
authors.forename: Xian-Pei
authors.initials: XP
authors.lastname: Wang
authors.forename: Ji-Hua
authors.initials: JH
authors.lastname: Ma
authors.forename: Pei-Hua
authors.initials: PH
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D015687:Cell Hypoxia; D006168:Guinea Pigs; D006352:Heart Ventricles; D008564:Membrane Potentials; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D012964:Sodium / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism*
chemical_list: D015222:Sodium Channels; D012964:Sodium; D010100:Oxygen; D002118:Calcium