Koh D S, Vogel W
Physiologisches Institut, Justus-Liebig-Universität, Giessen, Germany.
Pflugers Arch. 1993 Mar;422(6):609-13. doi: 10.1007/BF00374009.
A rapid exchange (less than 2 ms) of the bath solution facing a membrane patch is accomplished by driving the tip of a pipette from the bath through a 100-microns oil layer into a small capsule filled with 10 microliters test solution. The microcapsule method can be applied to both excised patch configurations, inside-out and outside-out patches. On and off reactions of Ca(2+)-activated K+ channel activity have been recorded after changing the intracellular Ca2+ concentration using an inside-out patch. A blockade of these K+ channels by external tetraethylammonium ions is demonstrated with an outside-out patch. The blocking kinetics of delayed-rectifier K+ channels by a purified peptide toxin from snake venom, dendrotoxin, could be measured with our microcapsule method. Using tiny volumes of test solutions this method can be helpful in experiments involving scarce or expensive solutions.
通过将移液管尖端从浴槽中穿过100微米的油层，插入一个装有10微升测试溶液的小胶囊中，可实现面向膜片的浴槽溶液的快速交换（小于2毫秒）。微胶囊方法可应用于两种切除膜片配置，即内面向外和外面向外的膜片。使用内面向外的膜片改变细胞内Ca2+浓度后，记录了Ca(2+)激活的K+通道活性的开启和关闭反应。使用外面向外的膜片证明了外部四乙铵离子对这些K+通道的阻断作用。用我们的微胶囊方法可以测量来自蛇毒的纯化肽毒素——树突毒素对延迟整流K+通道的阻断动力学。由于使用的测试溶液体积很小，该方法有助于涉及稀缺或昂贵溶液的实验。
