Willoughby J O, Menadue M F, Liebelt H J
Centre for Neuroscience, Flinders University of South Australia, Bedford Park.
Neuroendocrinology. 1988 Jan;47(1):83-7. doi: 10.1159/000124895.
Prolactin concentrations were measured in plasma in unanaesthetized male rats chronically prepared with venous and intracerebral cannulae, before and after treatment with bilateral intracerebral injections of serotonin and fenfluramine. Serotonin 1, 5, and 10 nmol injected in the medial basal hypothalamus caused dose-related rises in prolactin concentrations. The secretion of prolactin was blocked by metergoline (2.5 mg/kg i.p.) and only partially by ketanserin (2.0 mg/kg i.v.). The 5-HT 1A agonist 8-OH-DPAT potently stimulated prolactin at doses of 1 and 5 nmol. Fenfluramine 10 and 100 nmol also caused increases in plasma prolactin when injected in the basal hypothalamus. Prolactin secretion was also evoked by serotonin injections in the preoptic/anterior hypothalamic area, but the response was not blocked by serotonin receptor antagonists. It is concluded that activation of 5-HT 1A receptors on or near prolactin-regulating neurons in the arcuate nucleus causes secretion of prolactin. The effectiveness of fenfluramine in increasing plasma prolactin suggests that endogenous serotonin released from terminals in the basal hypothalamus may mediate prolactin secretion physiologically.
在未麻醉的、长期植入静脉和脑内套管的雄性大鼠中，在双侧脑内注射血清素和芬氟拉明治疗前后，测量血浆中的催乳素浓度。在内侧基底下丘脑注射1、5和10 nmol血清素会导致催乳素浓度呈剂量相关升高。催乳素的分泌被美替拉酮（2.5 mg/kg腹腔注射）阻断，而酮色林（2.0 mg/kg静脉注射）仅部分阻断。5-HT 1A激动剂8-OH-DPAT在1和5 nmol剂量时能有效刺激催乳素分泌。在基底下丘脑注射10和100 nmol芬氟拉明也会导致血浆催乳素升高。在视前区/下丘脑前部注射血清素也能诱发催乳素分泌，但该反应未被血清素受体拮抗剂阻断。结论是，弓状核中催乳素调节神经元上或其附近的5-HT 1A受体激活会导致催乳素分泌。芬氟拉明增加血浆催乳素的有效性表明，从基底下丘脑终末释放的内源性血清素可能在生理上介导催乳素分泌。
