中文摘要：

目的：研究分离培养的大鼠骨髓间充质干细胞（BMSCs）膜表面离子通道的表达，为研究干细胞在分化过程中离子通道变化奠定基础。方法：采用Percoll分离液体外分离法，体外培养出能稳定传代的大鼠BMSCs，利用膜片钳技术记录BMSCs的离子电流。通过设定不同的实验程序，记录通道电流的幅度、激活和失活电流的峰值与时程、离子通道的选择性、Ⅰ—Ⅴ曲线。利用各种通道阻滞剂对记录到的电流进行鉴定、分析。结果：培养的细胞接种后24h开始贴壁，传代后细胞呈漩涡状。流式细胞术检测培养的细胞CD71、CD44呈阳性，CD34、CD45阴性，证实其为大鼠BMSCs。利用膜片钳技术在大鼠BMSCs上记录到延迟整流钾电流，并且在24％的BMSCs中发现了对河豚毒素（TTX）敏感的钠电流，在25％的BMSCs中记录到L-型电压依赖型钙电流。RT-PCR法证实BMSCs存在SCN5A、Kv4．3和CACNA1C3种通道。结论：记录到的离子电流具有兴奋细胞的特点。

英文摘要：

Objective To investigate the expression of ionic channels of the rat bone marrow mesenchymal stem cells （BMSCs） and provide the basis for the change of ionic channels in the process of differentiation of stem cells. Methods The full marrow from Wistar rats was isolated by Percoll eentrifugation and passaged repeatedly. The membrane currents of BMSCs were recorded with the whole-cell patch clamp technique. The current amplitude of pathway, peal value and time course of activation and deactivation, selectivity of ions pathway, Ⅰ-Ⅴ curve were recorded. The currents were identified and analyzed by using various channel blockers. Results The cells began to stick in 24 h and arranged in whirlpool shape after passenger culture. They were positive for CD71, CD44, and negative for CD34, CD45 by flow cytometry, which improved that the cultured cells were BMSCs. The functional ion channels were characterized in cultured rat BMSCs with whole-cell patch clamp and reverse transcription polymerase chain reaction （RT-PCR） techniques. Three types of outward currents were found in BMSCs, including a delayed rectifier K^＋ current （IKDR）, in addition, tetrodotoxin-sensitive sodium current （INa. TTX） and nifedipine-sensitive L-type Ca^2＋ current （ICa. L） were detected in 24% and 25% BMSCs. Moreover, RT-PCR result revealed the molecular evidence of mRNA for the functional ionic currents, including SCNSA, Kv4.3 and CACNA1C. Conclusion The currents are consistent with the characteristics of excitable cell membrane.