Simamura Eriko, Shimada Hiroki, Shoji Hiroki, Otani Hiroki, Hatta Toshihisa
Department of Anatomy I, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
Congenit Anom (Kyoto). 2011 Jun;51(2):47-54. doi: 10.1111/j.1741-4520.2011.00316.x.
Melanocortins, adrenocorticotropic hormone (ACTH) and α-, β-, and γ-melanocyte-stimulating hormone (MSH) are produced in the placenta and secreted into embryos/fetuses. ACTH concentrations are higher in fetal plasma than in maternal plasma and peak at mid-gestation in rats, whereas ACTH production starts in the anterior lobe of the fetal pituitary at later stages. Melanocortin receptors (MC1-5R), receptors for ACTH and α-, β- and γ-MSH, are expressed in various adult organs. The specific function of these receptors has been well examined in the hypothalamic-pituitary-adrenocortical (HPA) axis and the HPA axis-like network in the skin, and anti-inflammatory effects for white blood cells have also been investigated. MC2R and/or MC5R are also expressed in the testis, lung, kidney, adrenal, liver, pancreas, brain and blood cells at different stages in mouse and rat embryos/fetuses. Melanocortins in embryos and fetuses promote maturation of the HPA axis and also contribute to the development of lung, testis, brain and blood cells. Recently, a unique ACTH function was revealed in fetuses: placental ACTH, which is secreted by the maternal leukemia inhibitory factor (LIF), and induces LIF secretion from fetal nucleated red blood cells. Finally, the maternal LIF-placental ACTH-fetal LIF signal relay regulates the LIF level and promotes neurogenesis in fetuses, which suggests that ACTH acts as a signal transducer or effector for fetal development in the maternal-fetal signal pathway.
促黑素、促肾上腺皮质激素（ACTH）以及α-、β-和γ-黑素细胞刺激素（MSH）在胎盘中产生并分泌到胚胎/胎儿体内。胎儿血浆中的ACTH浓度高于母体血浆，在大鼠妊娠中期达到峰值，而ACTH的产生在妊娠后期才开始于胎儿垂体前叶。促黑素受体（MC1 - 5R），即ACTH以及α-、β-和γ-MSH的受体，在多种成体器官中表达。这些受体的具体功能已在下丘脑-垂体-肾上腺皮质（HPA）轴以及皮肤中类似HPA轴的网络中得到充分研究，同时也对白细胞的抗炎作用进行了研究。MC2R和/或MC5R在小鼠和大鼠胚胎/胎儿的不同阶段，也在睾丸、肺、肾、肾上腺、肝脏、胰腺、脑和血细胞中表达。胚胎和胎儿体内的促黑素促进HPA轴的成熟，也有助于肺、睾丸、脑和血细胞的发育。最近，在胎儿中发现了ACTH的一种独特功能：由母体白血病抑制因子（LIF）分泌的胎盘ACTH，可诱导胎儿有核红细胞分泌LIF。最后，母体LIF - 胎盘ACTH - 胎儿LIF信号传递调节LIF水平并促进胎儿神经发生，这表明ACTH在母胎信号通路中作为胎儿发育的信号转导器或效应器发挥作用。
