Effect of Ag+ on membrane permeability of perfused Helix pomatia neurons

Györi, J; Kiss, T; Shcherbatko, AD; Belan, PV; Tepikin, AV; Osipenko, ON; Salánki, J

HERO ID

225171

Reference Type

Journal Article

Year

1991

Language

English

PMID

1665853

HERO ID 225171
In Press No
Year 1991
Title Effect of Ag+ on membrane permeability of perfused Helix pomatia neurons
Authors Györi, J; Kiss, T; Shcherbatko, AD; Belan, PV; Tepikin, AV; Osipenko, ON; Salánki, J
Journal Journal of Physiology
Volume 442
Page Numbers 1-13
Abstract 1. Isolated, non-identified neurons were voltage clamped using the internal perfusion technique. 2. Ions of Ag+ (1-100-mu-M) introduced into the bathing solution activated a steady-state inward current (I(Ag)) in the soma. The effect of Ag+ was reversible when the concentration of Ag+ was less than 75-mu-M or the time of alication was shorter than 10 min. 3. I(Ag) was observed both in the presence and absence of Na+ ions in the extracellular saline. It could also be activated when Cs+ ions were substituted for Na+ ions. 4. The current-voltage characteristics were linear in the voltage range - 100 to 0 mV. The revrsal potential in control saline was an average of 1.19 +/- 5.1 mV. 5. The application of Ag+ ions induces an elevation of intracellular free Ca2+ concentration by 10-20 times in both Ca2+-containing and Ca2+-free extracellular salines, as revealed by Fura-2 measurements. 6. Agents that increase the intracellular free Ca2+ concentration ([Ca2+]i), like thymol, caffeine and dinitrophenol, increased the amplitude of I(Ag). The effect was additive. Ruthenium Red, which blocks the release of Ca2+ from intracellular stores, decreased the Ag+ effect. 7. It is concluded that extracellularly applied Ag+ ions increase the cytoplasmic free Ca2+ concentration, which in turn activates non-specific cationic channels. 8. Ag+ ions in 1-10-mu-M concentration were able to decrease the voltage-activated Ca2+ current amplitude. This decrease, however, was due to the increase of [Ca2+]i which caused Ca2+-dependent inactivation.
Pmid 1665853
Url http://jp.physoc.org/content/442/1/1
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword SARCOPLASMIC-RETICULUM; MOLLUSCAN NEURONS; SKELETAL-MUSCLE; CATION CHANNELS; CALCIUM CURRENT; SNAIL NEURONS; CA-2+ RELEASE; INWARD; CA; CONDUCTANCE
Is Qa No