PATCH-CLAMP STUDIES IN HUMAN MACROPHAGES - SINGLE-CHANNEL AND WHOLE-CELL CHARACTERIZATION OF 2 K+ CONDUCTANCES
PATCH-CLAMP STUDIES IN HUMAN MACROPHAGES - SINGLE-CHANNEL AND WHOLE-CELL CHARACTERIZATION OF 2 K+ CONDUCTANCES
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DOI：
10.1007/bf01871932
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发表时间：
1988-07-01
影响因子：
2.4
通讯作者：
MCKINNEY, LC
中科院分区：
文献类型：
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作者：
GALLIN, EK;MCKINNEY, LC
使用全细胞和单通道膜片钳记录技术研究了培养不同时间的人外周血单核细胞。全细胞记录显示，向外的K电流在电位bbb20 mV时激活，向内的K电流在电位负至-60 mV时存在。激活向外电流的电压阶跃引起的尾电流在EK附近反转，表明向外电流是由K电导引起的。宏观外向电流的I-V曲线与这些细胞中存在的大电导（对称K为240 pS）钙激活K通道的平均单通道I-V曲线相似。TEA和charybdotoxin阻断了全细胞向外电流和单通道电流。切除和细胞附着的单通道数据显示，新鲜分离的单核细胞中不存在钙激活的K通道，但在培养> 7天的巨噬细胞斑块中，有85%的斑块存在钙激活的K通道。培养bb70天的人巨噬细胞中只有35%表现出全细胞内向电流。向内电流被外钡阻挡，并随着[K]o的增大而增大。向内整流的单通道电流，电导为28ps，存在于细胞中，表现出向内的全细胞电流。这些单通道电流与J774中详细描述的电流相似。1细胞。
Human peripheral blood monocytes cultured for varying periods of time were studied using whole-cell and single-channel patch-clamp recording techniques. Whole-cell recordings revealed both an outward K current activating at potentials > 20 mV and an inwardly rectifying K current present at potentials negative to -60 mV. Tail currents elicited by voltage steps that activated outward current reversed near EK, indicating that the outward current was due to a K conductance. The I-V curve for the macroscopic outward current was similar to the mean single-channel I-V curve for the large conductance (240 pS in symmetrical K) calcium-activated K channel present in these cells. TEA and charybdotoxin blocked the whole-cell outward current and the single-channel current. Excised and cell-attached single-channel data showed that calcium-activated K channels were absent in freshly isolated monocytes but were present in > 85% of patches from macrophages cultured for > 7 days. Only 35% of the human macrophages cultured for > 7 days exhibited whole-cell inward currents. The inward current was blocked by external barium and increased when [K]o increased. Inward-rectifying single-channel currents with a conductance of 28 pS were present in cells exhibiting inward whole-cell currents. These single-channel currents are similar to those described in detail in J774. 1 cells.