大鼠脑神经末梢颗粒中钠转运的研究。

Studies on sodium transport in rat brain nerve-ending particles.

作者信息

Ling C M, Abdel-Latif A A

机构信息

Illinois State Pediatric Institute, Department of Psychiatry University of Illinois College of Medicine, USA.

出版信息

J Neurochem. 1968 Aug;15(8):721-9. doi: 10.1111/j.1471-4159.1968.tb10316.x.

DOI:10.1111/j.1471-4159.1968.tb10316.x

PMID:18561483

Abstract

(1) Nerve-ending particles isolated from crude mitochondrial preparations from rat brain by discontinuous Ficoll density gradient ultracentrifugation were shown to possess a Mg2+ and energy-dependent transport system for Na+. (2) Ouabain or iodoacetate plus cyanide exerted an inhibitory effect on the outflux but not the influx of Na+. (3) When K+ was added to a medium containing particles loaded with Na+ (22Na), an immediate release of Na+ from these particles was observed; this suggests the existence of a Na+-K+ exchange transport system. (4) The K+ effect was inhibited by 10(-4) M-ouabain only at low (about 3.3 mM), but not at high (20 mM), K+ concentrations. (5) The uptake and release of Na+ by the nerve-ending particles were found to be temperature-dependent. (6) Only nerve-ending particles with intact synaptosomal membranes were found to transport Na+ actively.

摘要

(1) 通过不连续的菲可密度梯度超速离心从大鼠脑粗线粒体制剂中分离出的神经末梢颗粒，被证明具有一种依赖镁离子和能量的钠离子转运系统。(2) 哇巴因或碘乙酸加氰化物对钠离子外流有抑制作用，但对钠离子内流无抑制作用。(3) 当向含有负载钠离子（22Na）的颗粒的培养基中加入钾离子时，观察到这些颗粒立即释放钠离子；这表明存在钠离子 - 钾离子交换转运系统。(4) 仅在低（约3.3 mM）钾离子浓度下，而非高（20 mM）钾离子浓度下，10(-4) M哇巴因可抑制钾离子效应。(5) 发现神经末梢颗粒对钠离子的摄取和释放依赖于温度。(6) 仅发现具有完整突触体膜的神经末梢颗粒能主动转运钠离子。