Enjalbert A, Arancibia S, Ruberg M, Priam M, Kordon C
J Physiol (Paris). 1980 Jul;76(3):227-31.
In order to identify prolactin regulating factors, the effect of various neuropeptides on prolactin secretion by the adenohypophysis has been tested. 1 degree Histidyl-proline-diketopiperazine (DKP), a major degradation product of TRH in hypothalamus and pituitary, inhibited prolactin secretion from incubated hemipituitaries (Fig. 1) with an apparent affinity of 0.5 nM. Histidyl-prolineamide and histidyl-proline, other degradation products of TRH, had no effect. TSH secretion was not affected under the same conditions. 2 degrees Vasoactive intestinal peptide (VIP) stimulated prolactin secretion in vitro in a dose dependent manner. The secretion of other adenohypophyseal hormones was not affected. This effect is not mediated by a dopaminergic mechanism, since it was not blocked by neuroleptics (Table I). 3 degrees Morphinomimetic peptides had no effect on prolactin secretion in vitro, but blocked the dopamine inhibition of prolactin secretion. The effect of metenkephalin and beta-endorphin was dose dependent and was blocked by naloxone (Fig. 2 and 3). Thse results indicate that specific receptors to various neuropeptides seem to be present on prolactin cells.
为了鉴定催乳素调节因子，已经测试了各种神经肽对腺垂体催乳素分泌的影响。1. 组氨酰 - 脯氨酸二酮哌嗪（DKP）是下丘脑和垂体中促甲状腺激素释放激素（TRH）的主要降解产物，它以0.5 nM的表观亲和力抑制孵育的半垂体分泌催乳素（图1）。TRH的其他降解产物组氨酰 - 脯氨酰胺和组氨酰 - 脯氨酸则没有作用。在相同条件下促甲状腺激素（TSH）的分泌不受影响。2. 血管活性肠肽（VIP）在体外以剂量依赖性方式刺激催乳素分泌。其他腺垂体激素的分泌不受影响。这种作用不是由多巴胺能机制介导的，因为它不受神经安定药的阻断（表I）。3. 阿片样肽在体外对催乳素分泌没有作用，但能阻断多巴胺对催乳素分泌的抑制作用。甲硫脑啡肽和β-内啡肽的作用是剂量依赖性的，并且被纳洛酮阻断（图2和3）。这些结果表明催乳素细胞上似乎存在各种神经肽的特异性受体。
