南方医科大学学报2011，Vol.31Issue(3)：490-494,5.
小电导钙激活钾通道在人心房肌细胞中的表达及功能
Expression and functional role of small conductance Ca2+-activated K+ channels in human atrial myocytes
摘要
Abstract
To investigate the expression and functional role of the small conductance Ca2 +-activated K+ channels in human atrial myocytes. Methods We collected the right atrial appendage tissues from 8 patients with congenital heart defect with sinus rhythm undergoing open-heart surgery. Immunohistochemistry was performed to identify the expression of 3 isoforms of SK channel (SKI, SK2 and SK3). Using the classical two-step enzymatic isolation method, perforated patch clamp and conventional voltage-clamp techniques were performed to record the action potentials (Aps) and the whole-cell Ca2+-activated K+ current (Ik. C.) in the single atrial myocyte. We compared the changes in action potential duration (APD) before and after the application of a specific SK channels blocker apamin (100 nmol/L). Results Human atrial myocytes showed positivity for all the SKI, SK2 and SK3 isoform channels. Patch-clamp recording confirmed the presence of Ik,ca, and apamin significantly prolonged APD at 90% repolarization (APD90), but produced no obvious effect on APD50. Conclusion The three isoforms of SK channels are all expressed in human atrial myocytes. SK channels play a prominent role in the late phase of repolarization in human atrial myocytes, which is distinct from their functional roles in neurons where they mediate the process of afterhyperpolarization following Aps.关键词
小电导钙激活钾通道/人/心房肌细胞/膜片钳Key words
small conductance Ca2+-activated K+ channels/ human/ atrial myocytes/ patch-damp technique分类
医药卫生引用本文复制引用
于涛,吴若彬,郭惠明,邓春玉,郑少忆,邝素娟..小电导钙激活钾通道在人心房肌细胞中的表达及功能[J].南方医科大学学报,2011,31(3):490-494,5.基金项目
广东省自然科学基金(8151008002000017) （8151008002000017）
