Fernández-Ruiz J J, Cebeira M, Agrasal C, Tresguerres J A, Bartke A, Esquifino A I, Ramos J A
J Endocrinol. 1987 Apr;113(1):45-9. doi: 10.1677/joe.0.1130045.
It was recently reported that anterior pituitary tissue transplanted to an ectopic site contains measurable amounts of dopamine and noradrenaline. To examine the possibility of local catecholaminergic control of prolactin secretion from ectopic pituitaries, pituitary grafted and sham-operated female rats were submitted to several pharmacological treatments modifying catecholamine synthesis. Administration of a single dose of alpha-methyl-p-tyrosine (alpha-MPT) significantly reduced dopamine content in the graft, while noradrenaline content was not modified. Similar changes in the contents of dopamine and noradrenaline after alpha-MPT administration were observed in the hypothalamus and in the in-situ pituitary in both grafted and sham-operated rats. Plasma concentrations of prolactin were increased in both grafted and sham-operated rats after administration of alpha-MPT. A single injection of L-3,4-dihydroxyphenylalanine (L-DOPA) increased dopamine content in the ectopic pituitary gland without altering the noradrenaline content, and produced similar effects in the hypothalamus and in-situ pituitary of grafted and control rats. Plasma prolactin concentrations were decreased by L-DOPA in both pituitary grafted and control rats. Administration of DL-treo-dihydroxyphenylserine (DOPS) increased noradrenaline content in the ectopic pituitary and reduced plasma prolactin concentrations in pituitary grafted rats. In contrast, injection of DOPS to control rats increased both hypothalamic noradrenaline content and plasma prolactin concentrations. These results suggest that dopamine and noradrenaline present in the ectopic pituitary tissue have a role in mediating prolactin release from pituitary transplants.
最近有报道称，移植到异位部位的垂体前叶组织含有可测量的多巴胺和去甲肾上腺素。为了研究异位垂体催乳素分泌的局部儿茶酚胺能控制的可能性，将移植垂体和假手术的雌性大鼠进行了几种改变儿茶酚胺合成的药理学处理。给予单剂量的α-甲基-对-酪氨酸（α-MPT）可显著降低移植组织中的多巴胺含量，而去甲肾上腺素含量未改变。在移植和假手术大鼠的下丘脑和原位垂体中，给予α-MPT后多巴胺和去甲肾上腺素含量也出现了类似变化。给予α-MPT后，移植和假手术大鼠的血浆催乳素浓度均升高。单次注射L-3,4-二羟基苯丙氨酸（L-DOPA）可增加异位垂体中的多巴胺含量，而不改变去甲肾上腺素含量，并在移植和对照大鼠的下丘脑和原位垂体中产生类似作用。L-DOPA可降低移植垂体和对照大鼠的血浆催乳素浓度。给予DL-苏式-二羟基苯丝氨酸（DOPS）可增加异位垂体中的去甲肾上腺素含量，并降低移植垂体大鼠的血浆催乳素浓度。相反，向对照大鼠注射DOPS可增加下丘脑去甲肾上腺素含量和血浆催乳素浓度。这些结果表明，异位垂体组织中存在的多巴胺和去甲肾上腺素在介导垂体移植催乳素释放中起作用。
