Effects of stretch on transient outward potassium and inward rectifier po-tassium current in cultured neonatal rat atrial myocytes
10.3969/j.issn.1000-4718.2014.08.026
- VernacularTitle:牵张刺激对乳大鼠心房肌细胞瞬时外向钾电流和内向整流钾电流的影响
- Author:
Yanan XU
;
Long YANG
;
Tianhe YANG
;
Chunyu DENG
;
Lin LUO
;
Zhifang QIN
;
Qian TANG
;
Jun YANG
- Publication Type:Journal Article
- Keywords:
Stretch;
Atrial myocytes;
Patch-clamp techniques;
Potassium current;
Action potential
- From:
Chinese Journal of Pathophysiology
2014;(8):1489-1492
- CountryChina
- Language:Chinese
-
Abstract:
[ABSTRACT]AIM:Toinvestigatetheeffectsofmechanicalstretchontransientoutwardpotassiumcurrent(Ito), inward rectifier potassium current ( IK1 ) and action potential duration ( APD) of cultured neonatal rat atrial myocytes . METHODS:Neonatal rat atrial myocytes were isolated and cultured on silicone sheeting with or without stretch for 24 h. The silicone membrane area was increased by 12%in stretched group.The cells without stretch served as control .Ito, IK1 and APD were recorded by the technique of whole-cell patch clamp.RESULTS:Compared with control group, Ito density in stretched myocytes was significantly reduced [(1.6 ±0.4) pA/pF vs (12.1 ±2.9) pA/pF, P<0.01], whereas IK1 density was increased [(-10.8 ±0.8) pA/pF vs (-8.8 ±0.9) pA/pF, P<0.01].The APDs at 50%and 90%levels of repolarization ( APD50 and APD90 ) in the stretched cells were obviously decreased than those in non-stretched cells [(10.5 ±1.4) ms vs (15.5 ±2.4) ms, (30.0 ±2.8) ms vs (56.3 ±3.6) ms, P<0.01].CONCLUSION: Stretch stimulation leads to the reduction of Ito density, the increase in IK1 density and the shortness of APD in cultured rat atrial neonatal myocytes , which may contribute to atrial electrical remodeling induced by pressure overload .
