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ID 30799
JaLCDOI
FullText URL
Author
Secilmis, Ata
Atci, Serare
Yaktubay, Naciye
Karatas, Yusuf
Gocmen, Cemil
Singirik, Ergin
Dikmen, Atilla
Baysal, Firuz
Abstract

 The aim of the study was to investigate whether Na+ channels play a role in the twitch component of the response of the isolated frog rectus abdominis to Ca2+-free Ringer solution with 0.2 mM Na2EDTA by using tetrodotoxin and some other well known drugs that exhibit a blocking action on Na+ channels. In the presence of 5 x 10-7 M tetrodotoxin, the twitch component, measured isotonically, disappeared. Although 10-7 M d-tubocurarine was found to be ineffective, a complete blockage of twitch amplitude was observed at 5 x 10-6 M concentration of the drug. The inhibitory action of d-tubocurarine on twitch response was not antagonized by 10-6 and 10-5 M carbachol. Propranolol (10-6 - 10-5 M), lidocaine (2 x 10-6 - 10-5 M), quinine (10-6 - 2 x 10-5 M) and quinidine (10-6 - 2 x 10-5 M) inhibited maximal twitch amplitude in a concentration dependent manner. These findings strongly suggest that activation of tetrodotoxin sensitive Na+ channel may play a primary role at twitch generation during exposure of the frog rectus abdominis to Ca2+-free Ringer solution with Na2 EDTA.

Keywords
tetrodotoxin
Ca<sup>2+</sup>-free medium with Na<sub>2</sub> EDTA
isolated frog rectus abdominis
Na<sup>+</sup> channel blocking activity
Amo Type
Article
Published Date
1997-06
Publication Title
Acta Medica Okayama
Volume
volume51
Issue
issue3
Publisher
Okayama University Medical School
Start Page
115
End Page
120
ISSN
0386-300X
NCID
AA00508441
Content Type
Journal Article
language
英語
File Version
publisher
Refereed
True
PubMed ID
Web of Sience KeyUT