首页 | 本学科首页   官方微博 | 高级检索  
     


Hydrogen currents through aconitine-modified sodium channels in the nerve fiber membrane
Authors:G. N. Mozhaeva  A. P. Naumov
Abstract:Ionic currents through aconitine-modified sodium channels of the Ranvier node membrane were measured by a voltage clamp method in an external medium free from sodium ions. A shift of pH of the solution below 4.6 led to the appearance of inward ionic currents, whose kinetics and activation region were characteristic of aconitine-modified sodium channels at low pH. These currents were blocked by the local anesthetic benzocaine in a concentration of 2 mM. Experiments with variation of the concentration of Ca++, Tris+, TEA+, and choline+ in acid sodium-free solutions showed that these cations make no appreciable contribution to the inward current. It is concluded that the inward currents observed under these conditions are carried by H+ (or H3O+) through aconitine-modified sodium channels. From the shifts of reversal potentials of the ionic currents the relative permeability (PH/PNa) for H+ was determined: 1059 ± 88. The results agree with the view that the aconitine-modified sodium channel is a relatively wide water pore, and that movement of H+ through it is limited by its binding with an acid group.Institute of Cytology, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 14, No. 5, pp. 508–516, September–October, 1982.
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号