Age-related changes in activation and inactivation kinetics of the Na channels in cultured heart muscle from chick embryo

ヒヨコ胚培養心筋細胞でのNaチャネルの活性・不活性化パラメータの加令による変化

Age-related changes in activation and inactivation kinetics of the Na channels in cultured heart muscle from chick embryo

Creators Fujita Takeshi

Creators Ebina Yoshio

Creators Sada Hideaki

Creators Toshitani Hideo

Creators Nakajima Kazuki

Creators Ban Takashi

To investigate age-related changes in Na^+ channel kinetics, ventricular cells obtained from chick embryos of various developmental stages were voltage-clamped with patch pipettes, and the Na^+ current (I_<Na>) together with the membrane potential (V_m) were recorded (16℃). The data stored in VTR as PCM signal was A/D converted and analyzed in terms of Hodgkin-Huxley model. I_<Na> underwent the activation/inactivation sequence in response to change in V_m. While the activation kinetics little changed throughout embryogenesis, the inactivation kinetics was altered with embryonic development. Yet, the density of Na^+ channel per unit membrane area also was drastically increased with development. We discuss the present voltage-clamp data in comparison with those obtained from different tissues and/or animal species.

[ISSN]0372-7661

[NCID]AN00244228