Increased small conductance calcium-activated potassium channel ( SK2 channel ) current in atrial myocytes of patients with persistent atrial fibrillation
10.3760/cma.j.issn.0253-3758.2011.02.013
- VernacularTitle:持续性心房颤动患者心房肌细胞小电导钙激活钾通道电流的增强
- Author:
Miao-Ling LI
1
;
Tao LI
;
Ming LEI
;
Xiao-Qiu TAN
;
Yan YANG
;
Tai-Peng LIU
;
Jie PEI
;
Xiao-Rong ZENG
Author Information
1. 泸州医学院
- Keywords:
Atrial fibrillation;
Ion channels;
Patch-clamp techniques;
Apamin
- From:
Chinese Journal of Cardiology
2011;39(2):147-151
- CountryChina
- Language:Chinese
-
Abstract:
Objective To compare the amplitude of the SK2 current (small conductance calciumactivated potassium channel ) in human atrial myicytes with or without persistent atrial fibrillation(AF).Methods Right atrial appendage was obtained from 15 patients with sinus rate (SR) and 7 patients with AF underwent surgical valve replacement. Single myocyte was isolated by enzymatic dissociation method and the SK2 channel current density was recorded using whole-cell patch clamp techniques to detect the changes.Immunofluorescence was used to observe SK2 channel protein distribution on right atrial appendage. Results Using the whole cell patch-clamp recording techniques, an inward rectifier K+ mix currents could be obtained from both SR (n = 15 ) and AF (n =7 ) samples, IK1 mix currents density in single myocyte of AF group was significantly increased than in SR group [( - 16. 42 ±5.32) pA/pF vs ( -6. 59 ±2. 24) pA/pF,P ＜0. 01], which could be partially inhibited by apamin (100 nmol/L). The apamin-sensitive current was obtained by subtraction of the currents before and after treatment with apamin. SK2 current density was significantly increased in AF group than that of SR group [( - 9. 81 ± 2. 54) pA/pF vs ( - 3.67 ± 0. 37)pA/pF,P ＜ 0. 01]. SK2 channel protein was evidenced with immunofluorescence method in right atrial appendage from AF group and SR group. Conclusion SK2 channel protein and current were present in atrial myocytes. The SK2 current density was significantly increased in AF group than in SR group suggesting that the increase of SK2 current might contribute to the electrical remodeling in AF patients.
