Walz W, Hertz L
J Cereb Blood Flow Metab. 1984 Jun;4(2):301-4. doi: 10.1038/jcbfm.1984.42.
An intense K+ accumulation in primary cultures of astrocytes, occurring when external K+ was increased from 5.4 to 54 mM, was investigated. This increase resulted in a doubling of the K+ content within 10 s. Thirty percent of the accumulation was inhibited by furosemide (2 mM). This drug had no effect on the unidirectional influx of K+ at 5.4 mM K+, but when the extracellular K+ concentration was increased, there appeared to be a furosemide-sensitive component of the influx. This component increased with increasing external K+ levels, reaching 44% of the total influx at 72 mM. These results show that astrocytes exhibit an intense furosemide-sensitive K+ accumulation which is activated by K+ levels resembling those occurring in the extracellular compartment during pathological events. Previous studies on a furosemide-sensitive Cl- pump in cultured astrocytes suggest that this accumulation might be via KCl cotransport, which in other systems is involved in volume control.
研究了原代培养星形胶质细胞中强烈的钾离子蓄积现象，该现象发生于细胞外钾离子浓度从5.4 mM增加到54 mM时。这种增加导致钾离子含量在10秒内翻倍。30%的蓄积被呋塞米（2 mM）抑制。该药物对5.4 mM钾离子浓度下钾离子的单向流入没有影响，但当细胞外钾离子浓度增加时，似乎存在一个对呋塞米敏感的流入成分。该成分随着细胞外钾离子水平的升高而增加，在72 mM时达到总流入量的44%。这些结果表明，星形胶质细胞表现出强烈的对呋塞米敏感的钾离子蓄积，这种蓄积由类似于病理事件期间细胞外间隙中出现的钾离子水平激活。先前对培养星形胶质细胞中对呋塞米敏感的氯离子泵的研究表明，这种蓄积可能是通过氯化钾共转运，而在其他系统中，氯化钾共转运参与了体积调节。
