How experimental conditions can influence the effects of toxins binding to "site 3" on sodium channel - electrophysiological observations

• Autorzy: Dabrowski M. , Nowak W. , Jankowska M. , Stankiewicz M.
• Języki publikacji: EN

Abstrakty

EN

Toxins binding to “site 3” on Na channel inhibit the inactivation of channel and often induce the plateau action potentials (AP). Effects of scorpion toxin LqhαIT and sea anemone toxin ATX II were observed on insect axonal preparation. Duration of AP increased progressively with time after toxin application. Time of plateau AP development was shorter in higher toxin concentration and length of AP was bigger. Although extension of plateau AP decreased with high frequency stimulation (HFS), the effect of HFS was depressed by higher toxin concentration (10-6 M). Elevated Ca2+ concentration has been determined as another factor which induced limitation of plateau AP duration. Modifications of sodium current under toxins correspond well to all observations done in current-clamp configuration. Toxin-induced late sodium current had smaller amplitude with high frequency depolarizing pulse application – such an effect was partially eliminated by increased toxin concentration. High Ca2+ concentration diminished current modification induced by toxins. The electrophysiological data were additionally compared with data obtained by theoretical binding calculations using ligand docking to all atom ion channel model. Supported by MNiSW (grant N N303 320637); Dąbrowski M. is a beneficiary of PhD grant: Project No POKL.04.01.01-00-081/10

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2012
• Tom: 72
• Numer: 2
• Opis fizyczny: p.199

Twórcy

autor

Dabrowski M.

• Institute of Physics, N.Copernicus University, Torun, Poland
• Institute of General and Molecular Biology, N.Copernicus University, Torun, Poland

autor

Nowak W.

• Institute of Physics, N.Copernicus University, Torun, Poland

autor

Jankowska M.

• Institute of General and Molecular Biology, N.Copernicus University, Torun, Poland

autor

Stankiewicz M.

• Institute of General and Molecular Biology, N.Copernicus University, Torun, Poland

Uwagi

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