Dual action of d-tubocurarine on large-conductance Ca2+-activated K+ channels from rat brain reconstituted into planar lipid bilayer.
- Author:
Sungkwon CHUNG
1
;
Jung Hoon SHIN
Author Information
1. Department of Physiology, Chung-Ang University College of Medicine, Seoul 156-756, Korea.
- Publication Type:Original Article
- Keywords:
Ca2+-activated k+Channel;
d-Tubocurarine;
Planar lipid bilayer
- MeSH:
Animals;
Binding Sites;
Brain*;
Lipid Bilayers*;
Molar;
Potassium Channels, Calcium-Activated*;
Rats*;
Tubocurarine*
- From:The Korean Journal of Physiology and Pharmacology
1998;2(5):549-553
- CountryRepublic of Korea
- Language:English
-
Abstract:
Using the planar lipid bilayer method, we investigated the effect of d-tubocurarine (dTC) on the extracellular side of large-conductance Ca2+-activated K+ channel from rat brain. When the initial open probability (Po) of the channel was relatively high, dTC decreased channel activity in a concentration dependent manner. In contrast, when the initial Po was lower, sub-micro molar dTC increased channel activity by destabilizing the closed states of the channel. Further addition of dTC up to micro molar range decreased channel activity. This dual effect of dTC implicates that there exist at least two different binding sites for dTC.
