Ikeda H, Greer M A
Am J Physiol. 1983 Jul;245(1):E32-7. doi: 10.1152/ajpendo.1983.245.1.E32.
Five adenohypophyses from donors of the same strain, age, and sex were transplanted under the renal capsule of young adult female rats. At least 3 wk later, enzymatically dispersed cells from eutopic or heterotopic adenohypophyses from the same rat were perifused in vitro in a small chamber. Thyrotropin (TSH) and prolactin (PRL) secretion per 10(6) cells were significantly less from heterotopic than from eutopic cells under all conditions. In cells from euthyroid animals, TRH induced TSH secretion only in the eutopic cells but induced PRL secretion in both eutopic and heterotopic cells. Hypothyroidism increased TRH-induced TSH secretion and content in the cell lysate in both eutopic and heterotopic cells but increased TRH-induced PRL secretion only in the eutopic cells. The increase in TSH secretion induced by hypothyroidism in the heterotopic cells was of borderline statistical significance. The inability of TRH to induce TSH secretion in heterotopic pituitary cells from euthyroid rats may be due to a lower set point for thyroid hormone inhibition of TSH secretion in the heterotopic thyrotrophs. Heterotopic pituitary TSH secretion is probably suppressed by the normal plasma thyroid hormone concentration maintained by the eutopic pituitary and may be stimulated by TRH only in the presence of a subnormal plasma thyroid hormone concentration.
将来自同一品系、年龄和性别的供体的五个腺垂体移植到成年雌性幼鼠的肾被膜下。至少3周后，将来自同一只大鼠的原位或异位腺垂体的酶分散细胞在体外置于一个小室中进行灌流。在所有条件下，每10^6个细胞的促甲状腺激素（TSH）和催乳素（PRL）分泌量，异位细胞均显著低于原位细胞。在甲状腺功能正常动物的细胞中，促甲状腺激素释放激素（TRH）仅诱导原位细胞分泌TSH，但诱导原位和异位细胞分泌PRL。甲状腺功能减退增加了原位和异位细胞中TRH诱导的TSH分泌以及细胞裂解物中的TSH含量，但仅增加了原位细胞中TRH诱导的PRL分泌。甲状腺功能减退在异位细胞中诱导的TSH分泌增加具有边缘统计学意义。甲状腺功能正常大鼠的异位垂体细胞中TRH不能诱导TSH分泌，可能是由于异位促甲状腺细胞中甲状腺激素抑制TSH分泌的设定点较低。异位垂体TSH分泌可能受到原位垂体维持的正常血浆甲状腺激素浓度的抑制，并且可能仅在血浆甲状腺激素浓度低于正常时受到TRH的刺激。
