Molecular Mechanism Responsible for Skeletal Muscle Contraction Induced by Gold Ion.
10.3777/jjsam.42.245
- VernacularTitle:金イオンによる骨格筋の収縮発現機序に関する研究
- Author:
Kenji NIHONYANAGI
;
Toshiharu OBA
- Publication Type:Journal Article
- From:Journal of the Japan Society of Acupuncture and Moxibustion
1992;42(3):245-251
- CountryJapan
- Language:Japanese
-
Abstract:
Effects of external Ca2+ depletion and chemical modification of SH groups in membrane protein on gold-induced contraction were studied to compare with those by silver ion with single toe muscle fiber of frog. Membrane potential and twitch tension were also measured after exposure of fibers to gold ion. In Ringer solution, gold produced phasic (P1) and subsequent tonic (P2) contractions. When Ca2+ was replaced by Mg2+, only P1 was elicited upon gold. Application of 5mM DTT to contracting fibers led to disappear the gold-induced tension rapidly and exponentially. The fiber pretreated with 0.05% H2O2 for 10min responded to occur no gold contraction. In such fibers paralyzed by H2O2, cleavage of SS bonds by DTT restored the responsiveness of fibers to gold ions. Gold ions depolarized the muscle membrane, dose-dependently. Twitch tension was first potentiated upon gold application, and then disappeared. These results indicate that action of gold ion on skeletal muscle is similar to that of Ag+, but the ability of chemical modification of sulfhydryls by gold ion in situ is much lesser than that by Ag+.
