石磺神经元中两个电压激活通道和一个乙酰胆碱激活通道的离子选择性

The ionic selectivity of two voltage activated channels and an acetylcholine activated channel in an Onchidium neuron.

Edwards C, Sawada M, Kato M, Akaike N, Shimizu M, Oomura Y

Comp Biochem Physiol C Comp Pharmacol. 1982;72(2):387-90. doi: 10.1016/0306-4492(82)90109-5.

Abstract

The selectivities of the ion channels underlying the action potential and the hyperpolarizing response to acetylcholine of the GH cell of Onchidium have been analysed. 2. The rising phase of the action potential is due to an increase in the permeability of the membrane to both Na+ and Ca2+. The Na+ channel is permeable to Li+ and is somewhat permeable to formamidinium, guanidinium and ammonium ions. The Ca2+ channel is permeable to Sr2+ and Ba2+, but not to Mn2+ and Mg2+. 3. The Cl- channel operated by ACh is permeable to chlorate, but not to formate and propionate ions. 4. The selectivities of these channels are similar to those of a number of other channels in other organisms.

摘要

分析了石磺GH细胞动作电位和对乙酰胆碱超极化反应所涉及的离子通道的选择性。2. 动作电位的上升期是由于膜对Na⁺和Ca²⁺的通透性增加所致。Na⁺通道对Li⁺有通透性，对甲脒离子、胍离子和铵离子也有一定通透性。Ca²⁺通道对Sr²⁺和Ba²⁺有通透性，但对Mn²⁺和Mg²⁺没有通透性。3. 由乙酰胆碱激活的Cl⁻通道对氯酸盐有通透性，但对甲酸盐和丙酸盐离子没有通透性。4. 这些通道的选择性与其他生物中的许多其他通道相似。