Sampson S R, Bannett R R, Shainberg A
J Neurosci Res. 1982;8(4):595-601. doi: 10.1002/jnr.490080404.
The effect of thyroxine (T4) was studied on the transmembrane resting potential (Em) of rat skeletal muscle cells in culture. In agreement with previous studies, we found the Em of developing muscle cells to increase with age from Day 3 to Day 7 or 8, at which time a plateau is reached. The values of Em we obtained (-65 to -75 mV) were 15-20 mV higher than those (-50 to -55 mV) reported by others. Treatment of mature myotubes with T4 resulted in a significant increase in resting Em. There was only a slight difference between T4-treated and control cells with regard to the relation between extracellular K+ concentration and resting Em. Within 20-30 min of exposure to ouabain (10(-4)--10(-3)M) resting Em of both T4-treated and control cells had fallen to about the same value. This effect was reversible. Thus, T4 stimulates the activity of an electrogenic Na/K-ATPase in the membrane of cultured skeletal muscle cells.
研究了甲状腺素（T4）对培养的大鼠骨骼肌细胞跨膜静息电位（Em）的影响。与先前的研究一致，我们发现发育中的肌肉细胞的Em在第3天到第7天或第8天随年龄增加，此时达到平台期。我们获得的Em值（-65至-75 mV）比其他人报道的值（-50至-55 mV）高15 - 20 mV。用T4处理成熟肌管导致静息Em显著增加。在细胞外K +浓度与静息Em的关系方面，T4处理的细胞与对照细胞之间只有轻微差异。在暴露于哇巴因（10（-4）- 10（-3）M）20 - 30分钟内，T4处理的细胞和对照细胞的静息Em都降至大致相同的值。这种效应是可逆的。因此，T4刺激培养的骨骼肌细胞膜中一种生电的Na / K - ATP酶的活性。
