摘要
目的 :研究人类小肠上皮细胞 (Intestine40 7cell lines)膜上钙激活性钾通道的分子生物学特征及其电生理学特性。方法 :用 RT- PCR方法检测培养的人类小肠上皮细胞膜上钙激活性钾通道的表达形式 ,用膜片钳的全细胞记录及单通道记录法探讨了该通道的电生理学特点。结果 :RT- PCR证实该细胞系有 interm ediate- conductance(IK)钙激活性钾通道表达 ,而没有 large- conductance(BK)和 small- conductance(SK)钙激活性钾通道的表达。电生理学研究表明 ,Ionom ycin引导的全细胞电流显示该钙激活性钾电流具有内向整流性并可被特异度 IK钙激活性钾通道阻断剂 clotrimazole所抑制 ,但特异度 SK钙激活性钾通道阻断剂 apam in对该电流无明显抑制作用。单通道记录法证实该通道的电导为 30± 2 p S,通道活性对细胞内 Ca2 +浓度有明显依赖性。结论 :分子生物学和电生理研究证实了人类小肠上皮细胞膜上有 IK钙激活性钾通道 。
The physilogical significance of the Caa?a(c)2+-activated K + channels has been described in a various tissues especially in epithelial cells. Due to their sensitivity to Caa?a(c)2+, these channels are very important elements in the coupling of intracellular Caa?a(c)2+ signaling to the electrical properties of the cells. This study was aimed at identifying the molecular identity for the K + channels in Intestine 407 cells. RT-PCR demonstrated that expression of an intermediatea2conductance Caa?a(c)2+-activated K + channels, whole-cell recordings demonstrated a inward rectify K + channel. Single channel data shown that its single channel conductance was 30±2 pS and its activity properties are consistent with intermediatea2conductance Caa?a(c)2+-activated K + channel in human erythrocytes.
出处
《心脏杂志》
CAS
2002年第1期7-12,共6页
Chinese Heart Journal
