Koenig R J, Smith R J
J Clin Invest. 1985 Aug;76(2):878-81. doi: 10.1172/JCI112046.
L6 cells have been investigated as a potential tissue culture model for the study of thyroid hormone effects on skeletal muscle metabolism. Differentiated L6 myotubes contained high-affinity triiodothyronine (T3) receptors with a Kd of 3 X 10(-10) M and a maximal binding capacity of 24 fmol T3/100 micrograms DNA. Undifferentiated cells contained receptors with the same Kd, but the binding capacity was reduced by at least a factor of three. Sarcoplasmic reticulum vesicle calcium pumping was demonstrated in L6 cell homogenates. The Vmax for calcium pumping was increased 2.5-fold when T3 was present in the culture medium, but the Kd was unchanged. L6 cells contained high affinity thyroid hormone receptors and were thyroid hormone responsive. These cells may be useful as a tissue culture model for studying the effects of thyroid hormones on skeletal muscle metabolism. In addition, the increase in T3 receptor number with the differentiated state suggests this as a model system for studying regulation of T3 receptor number and the role of T3 in the induction or maintenance of the differentiated state.
L6细胞已被作为一种潜在的组织培养模型进行研究,用于探讨甲状腺激素对骨骼肌代谢的影响。分化的L6肌管含有高亲和力的三碘甲状腺原氨酸(T3)受体,解离常数(Kd)为3×10⁻¹⁰ M,最大结合容量为24 fmol T3/100微克DNA。未分化的细胞含有具有相同Kd的受体,但结合容量至少降低了三分之一。在L6细胞匀浆中证实了肌浆网囊泡的钙泵作用。当培养基中存在T3时,钙泵的最大反应速度(Vmax)增加了2.5倍,但Kd不变。L6细胞含有高亲和力的甲状腺激素受体,且对甲状腺激素有反应。这些细胞可能作为一种组织培养模型,用于研究甲状腺激素对骨骼肌代谢的影响。此外,随着分化状态T3受体数量的增加,表明这是一个用于研究T3受体数量调节以及T3在诱导或维持分化状态中作用的模型系统。