PDF(Pubmed)
Abstract：
Serum prolactin (PRL) levels exhibit a gradual rise both in male and female rats from birth to adulthood, with females consistently displaying higher levels compared to age-matched males. This pattern has traditionally been attributed to the development and maturation of endocrine and neuroendocrine networks responsible for regulating PRL synthesis and secretion. However, the effect of dopamine (DA), which acts as an inhibitory factor on lactotroph function, also increases from birth to puberty, particularly in females. Nonetheless, the secretion of PRL remains higher in females compared to males. On the other hand, the observed sex differences in serum PRL levels during early postnatal development cannot be attributed to the influence of estradiol (E2). While serum E2 levels gradually increase after birth, only after 45 days of life do the disparities in E2 levels between females and males become evident. These observations collectively suggest that neither the maturation of hypothalamic DA regulation nor the rise in E2 levels can account for the progressive and sustained elevation in serum PRL levels and the observed sexual dimorphism during postnatal development. This review highlights the importance of recent discoveries in animal models that shed light on inhibitory mechanisms in the control of PRL secretion within the pituitary gland itself, that is intrapituitary mechanisms, with a specific emphasis on the role of transforming growth factor β1 and activins in PRL secretion.
摘要：
从出生到成年，雄性和雌性大鼠的血清催乳素（PRL）水平逐渐升高，与年龄匹配的男性相比，女性始终表现出更高的水平。传统上，这种模式归因于负责调节PRL合成和分泌的内分泌和神经内分泌网络的发育和成熟。然而,多巴胺（DA）的作用，作为催乳功能的抑制因子，从出生到青春期也会增加，尤其是女性。尽管如此，与男性相比，女性的PRL分泌仍然较高。另一方面,在出生后早期发育过程中观察到的血清PRL水平的性别差异不能归因于雌二醇（E2）的影响。而出生后血清E2水平逐渐升高，只有在生命45天后，女性和男性之间的E2水平差异才变得明显。这些观察结果共同表明，下丘脑DA调节的成熟或E2水平的升高都不能解释血清PRL水平的进行性和持续升高以及产后发育过程中观察到的性二态性。这篇综述强调了最近在动物模型中发现的重要性，这些发现阐明了垂体自身内PRL分泌控制的抑制机制。这是垂体内机制，特别强调转化生长因子β1和活化素在PRL分泌中的作用。
