Kimitsuki T, Nakagawa T, Hisashi K, Tsuji K, Komune S, Komiyama S
Department of Otorhinolaryngology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Acta Otolaryngol. 1998 Jan;118(1):70-3. doi: 10.1080/00016489850155152.
The concentration of intracellular calcium ion ([Ca2+]i) was altered in the same hair cell dissociated from a chick cochlea by the intrapipette perfusion technique. At a membrane potential of -40 mV, the elevation of [Ca2+]i generated outward-going currents within 60 sec when the intrapipette solution was based on KCl. In controls, at membrane potentials more positive than -50 mV, outward K+ currents were observed and at large positive potentials, the outward K+ current decreased, showing an N-shaped I-V relationship. This outward K+ current was increased by elevation of [Ca2+]i and was partially suppressed by a TEA-containing extracellular solution. We suggest that the Ca2+ increased by the intrapipette perfusion technique operates directly inside the cell membrane and activates Ca(2+)-activated K+ currents.
通过微量移液管灌注技术，在从鸡耳蜗分离出的同一个毛细胞中改变细胞内钙离子浓度（[Ca2+]i）。当微量移液管溶液以氯化钾为基础时，在 -40 mV 的膜电位下，[Ca2+]i 的升高在 60 秒内产生外向电流。在对照实验中，当膜电位比 -50 mV 更正时，观察到外向钾电流，而在大的正电位时，外向钾电流减小，呈现 N 形的电流-电压关系。这种外向钾电流随着 [Ca2+]i 的升高而增加，并被含有四乙铵的细胞外溶液部分抑制。我们认为，通过微量移液管灌注技术增加的 Ca2+ 在细胞膜内直接起作用，并激活钙激活钾电流。
