The effect of hypoxia-early reoxygenation on persistent sodium current in single ventricular myocytes of guinea pig.
- Author:
Xian-Pei WANG
1
;
Ji-Hua MA
;
Pei-Hua ZHANG
;
Jun LI
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Calcium; metabolism; Cell Hypoxia; Guinea Pigs; Heart Ventricles; Membrane Potentials; Myocytes, Cardiac; metabolism; physiology; Oxygen; metabolism; Patch-Clamp Techniques; Sodium; metabolism; Sodium Channels; metabolism
- From: Chinese Journal of Applied Physiology 2006;22(1):16-20
- CountryChina
- Language:Chinese
-
Abstract:
AIMTo 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.
METHODSThe 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.
CONCLUSIONThese results indicate that I(Na.P) has great significance in arrhythmogenesis and calcium-overload, which causes the following postischemia and post hypoxia myocardial damage.
