Nowak R A, Wiseman B S, Bahr J M
Biol Reprod. 1984 Aug;31(1):67-75. doi: 10.1095/biolreprod31.1.67.
The biological and immunological gonadotropin-releasing hormone (GnRH)-like activities in rabbit fetal placentas collected at Day 18 of gestation were investigated. Both crude and partially purified acid extracts of placental tissue were tested. A similarly prepared liver extract served as a control. Immunological GnRH-like activity, determined through a GnRH radioimmunoassay was 1.3-2.0 pg/mg protein for the crude placental extract, 7.1-9.2 pg/mg protein for the partially purified placental extract and was nondetectable for liver extract. Both the crude and partially purified placental extracts increased (P less than 0.01) luteinizing hormone (LH) release by dispersed rabbit pituitary cells, whereas the liver extract had no effect. The (Ac-D-p-Cl-Phe1,2, D-Trp3, D-Arg6, D-Ala10)-GnRH antagonist was used to determine whether the biological GnRH-like activity in the placental extract was mediated through GnRH receptors. All three doses of antagonist (10, 100 and 1000 ng) suppressed the biological GnRH-like activity in the placental extracts. Molecular sieve chromatography of the partially purified placental extract showed that the immunoreactive GnRH-like factor eluted in the same fractions as the GnRH standard. These data indicate that the rabbit fetal placenta has both immunological and biological GnRH-like activity.
对妊娠第18天采集的兔胎儿胎盘的生物学和免疫学促性腺激素释放激素（GnRH）样活性进行了研究。对胎盘组织的粗提物和部分纯化的酸提取物都进行了检测。同样制备的肝脏提取物用作对照。通过GnRH放射免疫测定法测定的免疫性GnRH样活性，粗胎盘提取物为1.3 - 2.0 pg/mg蛋白质，部分纯化的胎盘提取物为7.1 - 9.2 pg/mg蛋白质，肝脏提取物未检测到。粗胎盘提取物和部分纯化的胎盘提取物均增加（P小于0.01）分散的兔垂体细胞释放促黄体生成素（LH），而肝脏提取物无此作用。使用（Ac - D - p - Cl - Phe1,2, D - Trp3, D - Arg6, D - Ala10）- GnRH拮抗剂来确定胎盘提取物中的生物学GnRH样活性是否通过GnRH受体介导。所有三种剂量的拮抗剂（10、100和1000 ng）均抑制了胎盘提取物中的生物学GnRH样活性。对部分纯化的胎盘提取物进行分子筛色谱分析表明，免疫反应性GnRH样因子与GnRH标准品在相同的馏分中洗脱。这些数据表明兔胎儿胎盘具有免疫和生物学GnRH样活性。
