Effects of Goniopora toxin on the membrane currents of bullfrog atrial muscle

Mami Noda, Ikunobu Muramatsu, Motohatsu Fujiwara

研究成果: ジャーナルへの寄稿記事

7 引用 (Scopus)

抄録

The effects of Goniopora toxin (GPT), isolated from the Goniopora species, on the action potential and membrane currents of bullfrog atrial muscle were studied using the double sucrose-gap method. GPT at concentrations above 10 nmol/l prolonged the duration of the action potential and sometimes induced arrhythmias. The prolongation was also induced in the presence of Ca channel blockers (Mn or verapamil). These effects were not reversed by continuous superfusion of GPT-free solution, but were rapidly antagonized by tetrodotoxin (1 μmol/l). The resting potential was not affected by GPT. Voltage clamp experiments revealed that sustained inward current flows following the fast sodium current upon depolarization, in the presence of GPT. The current was elicited by the toxin in Mn-treated fibers and abolished in the presence of TTX. The delayed outward current (Ix) was slightly reduced; the background K current (IK1), inward background current (Ib) and slow inward current (Islow) were not altered by GPT. These results suggest that GPT acts on sodium channels to give rise to a prolonged sodium current which is in turn responsible for the prolongation of the action potential.

元の言語英語
ページ(範囲)75-80
ページ数6
ジャーナルNaunyn-Schmiedeberg's Archives of Pharmacology
327
発行部数1
DOI
出版物ステータス出版済み - 3 1 1984
外部発表Yes

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Rana catesbeiana
Muscles
Membranes
Action Potentials
Sodium
Sodium Channels
Tetrodotoxin
Verapamil
goniopora toxin
Membrane Potentials
Sucrose
Cardiac Arrhythmias

All Science Journal Classification (ASJC) codes

  • Pharmacology

これを引用

Effects of Goniopora toxin on the membrane currents of bullfrog atrial muscle. / Noda, Mami; Muramatsu, Ikunobu; Fujiwara, Motohatsu.

:: Naunyn-Schmiedeberg's Archives of Pharmacology, 巻 327, 番号 1, 01.03.1984, p. 75-80.

研究成果: ジャーナルへの寄稿記事

Noda, Mami ; Muramatsu, Ikunobu ; Fujiwara, Motohatsu. / Effects of Goniopora toxin on the membrane currents of bullfrog atrial muscle. :: Naunyn-Schmiedeberg's Archives of Pharmacology. 1984 ; 巻 327, 番号 1. pp. 75-80.
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