Kuromi H, Gonoi T, Hasegawa S
Brain Res. 1981 Jun;227(3):369-79. doi: 10.1016/0165-3806(81)90074-2.
We examined the trophic effects of a partially purified trophic substance from mouse spinal cord extract on the tetrodotoxin (TTX)-sensitivity of action potentials and on acetylcholine-sensitivity of rat skeletal myotubes in 7- and 8-day-old cultures. Many myotubes grown in control medium generate action potentials in the presence of TTX (10(-6) M). The addition of fraction E (Fr.E) from a Biogel P2 column, which exhibited trophic activity on adult denervated muscle in organ culture, decreased TTX-resistivity of action potentials of myotubes in cell culture. The trophic substance was also effective when further purified by paper chromatography and electrophoresis. The response to iontophoretically applied acetylcholine of Fr.E-treated myotubes was much more reduced by D-tubocurarine (10(-7) g/ml) than those of control cultured myotubes. No difference in morphological differentiation, protein synthesis, creatine phosphokinase activity or specific binding of [125I]alpha-bungarotoxin was observed between control and Fr.E-treated cultures. These results suggest that the trophic substance in Fr.E may be involved in the normal development of TTX-sensitive sodium channels and of acetylcholine receptor properties.
我们研究了从小鼠脊髓提取物中部分纯化的营养物质对7日龄和8日龄培养物中动作电位的河豚毒素（TTX）敏感性以及大鼠骨骼肌管乙酰胆碱敏感性的营养作用。许多在对照培养基中生长的肌管在存在TTX（10⁻⁶ M）的情况下产生动作电位。添加来自Biogel P2柱的组分E（Fr.E），其在器官培养中对成年去神经肌肉表现出营养活性，降低了细胞培养中肌管动作电位的TTX抗性。当通过纸色谱和电泳进一步纯化时，该营养物质也有效。与对照培养的肌管相比，用D - 筒箭毒碱（10⁻⁷ g/ml）处理的Fr.E处理的肌管对离子导入应用的乙酰胆碱的反应降低得更多。在对照和Fr.E处理的培养物之间，未观察到形态分化、蛋白质合成、肌酸磷酸激酶活性或[¹²⁵I]α - 银环蛇毒素的特异性结合有差异。这些结果表明，Fr.E中的营养物质可能参与了TTX敏感钠通道和乙酰胆碱受体特性的正常发育。
