蝾螈胚胎表皮细胞膜的静息电位,输入电阻与其兴奋性的关系

用微电极细胞内记录技术研究了东方蝾螈胚胎表皮细胞膜的静电位、输入电阻与其兴奋性的关系，在兴奋性形成期间正常胚胎表皮细胞的静息膜电位逐渐增大，膜的输入电阻逐渐减小。与不显示兴奋性的离体非典型胚胎表皮细胞相比，显示兴奋性的膜电位较高，膜电阻较低。用葡萄糖处理非典型表皮，在兴奋性出现同时，细胞膜超极化，膜电阻减小。用哇巴因处理表皮囊泡，在兴奋性消失同时，细胞膜去极化。结果表明，细胞能量供应不足所造成的膜

THE RELATION OF RESTING POTENTIAL AND INPUT RESISTANCE TO EXCITABI-LITY OF MEMBRANE IN THE EPIDERMAL EMBRYONIC CELLS OF CYNOPS ORIENTALIS

The relation of resting potential (RP) and input resistance (Rin) to excitability of membrane in the epidermal embryonic cells of Cynops orientalis was investigated with intracellular recording technique. During formation of excitability of the cells in embryonic epiderms in vivo (stages 23-28 epiderms) their RP gradually increased and their Rin gradually decreased. The excitable cells in atypical embryonic epiderms cultured in vitro reveal larger values of RP and smaller values of Rin than those of non-excitable cells. During treatment of atypical epiderms with 100 mmol/L glucose the cells became excitable and, at the same time, their membrane was hyperpolarized, their,Rin obviously decreased. During treatment of epidermal vesicles with 0. 1-1 mM ouabain the cells became non-excitable and, at same time, their membrane was depolarized. The results indicate that the bad electrical properties caused by insufficiency of energy supply in the cells might lead to disapearence of excitability of the cells in most atypical epiderms cultured in vitro. It is possible that the exogeneous energy supply caused apearence of excitability of the cells in atypical epiderms through improvement of electrical properties of membrane.