Human placental growth hormone
Human placental growth hormone
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DOI：
10.1016/s0002-9378(97)70103-0
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发表时间：
1997-12-01
影响因子：
9.8
通讯作者：
Evain-Brion, D
中科院分区：
文献类型：
--
作者：
Alsat, E;Guibourdenche, J;Evain-Brion, D
胎盘生长激素是GH-V基因的产物，在人胎盘的合体滋养层中特异性表达。胎盘生长激素与垂体生长激素有13个氨基酸的区别。它具有高的促生长和低的催乳活性。通过特异性单克隆抗体进行的测定显示，在母体循环中，从15至20周到足月，胎盘生长激素逐渐取代垂体生长激素，垂体生长激素变得无法检测。它由胎盘以非脉动方式分泌。这种持续分泌似乎对妊娠期的生理调节，特别是对母体胰岛素样生长因子-I水平的控制具有重要意义。胎盘生长激素分泌在体外和体内都受到葡萄糖的抑制，并且在宫内生长受限的妊娠中母体循环中显著减少。胎盘生长激素似乎对胎儿生长没有直接影响，因为这种激素在胎儿循环中检测不到。然而，生理作用也可能包括通过自分泌或旁分泌机制对胎盘发育的直接影响，如该组织中存在特异性生长激素受体所示。
Placental growth hormone is the product of the GH-V gene specifically expressed in the syncytiotrophoblast layer of the human placenta. Placental growth hormone differs from pituitary growth hormone by 13 amino acids. It has high somatogenic and low lactogenic activities. Assays by specific monoclonal antibodies reveal that in the maternal circulation from 15 to 20 weeks up to term placental growth hormone gradually replaces pituitary growth hormone, which becomes undetectable. It is secreted by the placenta in a nonpulsatile manner. This continuous secretion appears to have important implications for physiologic adjustment to gestation and especially in the control of maternal insulin-like growth factor-I levels. Placental growth hormone secretion is inhibited by glucose in vitro and in vivo and is significantly decreased in the maternal circulation in pregnancies with intrauterine growth restriction. Placental growth hormone does not appear to have a direct effect on fetal growth because this hormone is not detectable in the fetal circulation. However, the physiologic role might also include a direct influence on placental development through an autocrine or paracrine mechanism, as suggested by the presence of specific growth hormone receptors in this tissue.