Prolactin: A Pleiotropic Neuroendocrine Hormone

Abstract

The neuroendocrine control of prolactin secretion is unlike that of any other pituitary hormone. It is predominantly inhibited by the hypothalamus and, in the absence of a regulatory feedback hormone, it acts directly in the brain to suppress its own secretion. In addition to this short‐loop feedback action in the brain, prolactin has been reported to influence a wide range of other brain functions. There have been few attempts to rationalise why a single hormone might exert such a range of distinct and seemingly unrelated neuroendocrine functions. In this review, we highlight some of the original studies that first characterised the unusual features of prolactin neuroendocrinology, and then attempt to identify areas of new progress and/or controversy. Finally, we discuss a hypothesis that provides a unifying explanation for the pleiotrophic actions of prolactin in the brain.

Prolactin secretion patterns: basic mechanisms and clinical implications for reproduction

“…The surges occur autonomously every day at around 0300 and 1700 h for 10-14 days (Egli et al 2004). For a comparable figure on multiple modes of prolactin secretion, see also Grattan & Kokay (2008).…”

“…To illustrate the additional phases of pregnancy, more sophisticated mathematical models are necessary, similar to the ones we published earlier ). These models have been developed further and also take into account the termination of the oscillatory PRL secretion pattern that is based on a sustained increase in DA release associated with the onset of placental lactogen secretion (Grattan & Kokay 2008). The models, however, do not simulate the hyperprolactinemia situation of late pregnancy and lactation, which are most likely due to diminished responsiveness of the tuberoinfundibular DA (TIDA) neurons to PRL feedback (Arbogast & Voogt 1996).…”

“…More than 300 biological functions, for example immune functions, osmoregulation, reproduction, and behavior, have been described so far, and its pleiotropic features are unique (Freeman et al 2000, Grattan & Kokay 2008.…”

Современные Подходы К Диагностике И Лечению Гиперпролактинемии

“…Примечательно, что при отсутствии овуляции на фоне повышенного уровня пролактина не-редко наблюдается снижение концентрации эстрадиола, однако сохраняется нормальный уровень ФСГ и ЛГ. Исследования показали, что нарушение секреции ритма гонадотропных рилизинг-гормонов может быть главной причи-ной бесплодия при гиперпролактинемии [35]. Высказываются также предположения о том, что пролактин снижает чувствительность тка-ни яичников к действию гонадотропинов.…”

La prolactine et son fragment 16 kDa dans les tissus de mammifères

“…Localisation L'hypophyse antérieure est le principal site de production de la PRL [3], qui est aussi exprimée dans l'hypothalamus, les noyaux pré-optiques, paraventriculaires, périventriculaires et arqués [5] (Figure 1). Des formes clivées, PRL 14 kDa et 16K, ont été détectées dans les granules sécrétoires de l'adénohypophyse [6].…”