COMPARATIVE ASPECTS OF IONIC CONDUCTANCES IN NERVE AND HEART CELL MEMBRANES

这个项目是关于离子通道的比较分析。 神经和心脏细胞膜以及这些通道与 两种制剂的兴奋性。在过去的一年里，有一位 主要的实验制剂是鱿鱼巨型的轴浆 轴突。先前已发现轴浆中含有细胞器。 它又含有钾和钠离子通道，它们是 实际上与下面的各个离子通道相同 轴膜的兴奋性。这些细胞器似乎与 轴突膜，从而补充轴突中的这些通道。这 该项目的重点是对这些原始观察结果的后续行动。一 主要发现是细胞器可以根据 使用可控孔径、玻璃珠层析法测定大小。一大专业 用这种层析技术得到的细胞器组分接近 玻璃珠柱的50 nm尺寸点，它可能对应于 到顺行的细胞器。这些细胞器还被发现含有 基于电记录的钠和钾离子通道 来自包含在人工脂双层中的通道的电流。

This project is concerned with a comparative analysis of ion channels in nerve and heart cell membranes and the relationship of these channels to excitability in both preparations. During the past year, one of the primary experimental preparations has been the axoplasm from squid giant axons. The axoplasm has been previously shown to contain organelles which, in turn, contain potassium and sodium ion channels that are virtually identical to the respective ion channels underlying excitability in the axolemma. Those organelles appear to fuse with the axonal membrane, thereby replenishing these channels in the axon. This project has focused on a follow-up to these original observations. One major finding has been that the organelles can be separated on the basis of size using control-pore-size, glass bead chromatography. One major organelle fraction obtained with this chromatography technique lies near the 50 nm size point of the glass bead column, which probably corresponds to anterograde organelles. These organelles were also found to contain sodium and potassium ion channels based on recordings of electric currents from channels incorporated in artificial lipid bilayers.