Lewis M, Yeo P P, Green E, Evered D C
J Endocrinol. 1977 Sep;74(3):405-14. doi: 10.1677/joe.0.0740405.
Diced quarter anterior pituitaries from mature females Wistar rats were cultured in synthetic medium with or without added serum. Using each culture as its own control, the thyrotrophin-releasing hormone (TRH) dose-thyrotrophin (TSH) response characteristics of both media were similar; significant TSH secretion being stimulated at TRH doses around 1-5 X 10(-9) mol/l. During days 1-3 of culture, basal TSH secretion fell significantly but TRH responsiveness was unchanged. Neither tri-iodothyronine (T3) nor thyroxine (T4) influenced basal TSH secretion. In both culture media inhibition of TRH responsiveness was demonstrated with concentrations of T3 and T4 within the ranges 1-5 X 10(-12) to 1-5 X 10(-9) mol/l for T3 and 6-5 X 10(-10) to 6-5 X 10(-7) mol/l for T4. Equivalent inhibition was accompanied by similar T3 concentrations whether T3 or T4 supplements were used, suggesting that T4 itself has no feedback action. The similar concentrations of T3 required to inhibit TRH responsiveness in media either with or without serum suggest that the pituitary is responsive not only to free but also to total thyroid hormone concentrations, since serum-free medium contains no thyroid hormone-binding protein.
将成年雌性Wistar大鼠的垂体前叶切成四分之一大小的小块，在添加或不添加血清的合成培养基中培养。以每种培养物自身作为对照，两种培养基中促甲状腺激素释放激素（TRH）剂量-促甲状腺激素（TSH）反应特性相似；在TRH剂量约为1-5×10^(-9)mol/L时，可显著刺激TSH分泌。在培养的第1-3天，基础TSH分泌显著下降，但TRH反应性未改变。三碘甲状腺原氨酸（T₃）和甲状腺素（T₄）均不影响基础TSH分泌。在两种培养基中，当T₃浓度在1-5×10^(-12)至1-5×10^(-9)mol/L范围内，T₄浓度在6-5×10^(-10)至6-5×10^(-7)mol/L范围内时，均可证明TRH反应性受到抑制。无论使用T₃还是T₄补充剂，等效抑制均伴随着相似的T₃浓度，这表明T₄本身没有反馈作用。在有血清或无血清的培养基中，抑制TRH反应性所需的T₃浓度相似，这表明垂体不仅对游离甲状腺激素浓度有反应，而且对总甲状腺激素浓度也有反应，因为无血清培养基中不含甲状腺激素结合蛋白。
