Kinetics of placental lactogen in mid- and late-gestation ovine fetuses.
Kinetics of placental lactogen in mid- and late-gestation ovine fetuses.
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妊娠中期和晚期绵羊胎儿胎盘催乳素的动力学。
DOI：
10.1677/joe.0.1330095
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
A. Bell
中科院分区：
文献类型：
--
作者：
P. Schoknecht;W. B. Currie;A. Bell
胎盘催乳素（PL）在整个妊娠期间存在于胎儿血浆中，PL受体存在于许多类型的胎儿细胞上。在这项研究中，PL进入胎儿循环的进入率估计通过注射125I标记的绵羊PL到两个中期和四个晚期妊娠胎儿。在这两个年龄段，PL似乎分布到两个身体池。一个样本池的半衰期较短（约9 min），分布容积约为体重的8%，而第二个样本池的半衰期较长（约45 min），分布容积仅为体重的4%。第一个样本池可能是血浆，但第二个样本池的生理特性未知。PL的有效半衰期约为15分钟，肝脏被认为是可能的主要降解部位。这些估计值在妊娠晚期通过测量胎儿血浆中PL浓度来证实，以响应连续输注未标记的PL。本研究中估计的动力学参数可用于确定以可预测的方式改变胎儿血浆中PL浓度所需的外源性激素的量。
Placental lactogen (PL) is found in fetal plasma throughout gestation, and PL receptors occur on many types of fetal cells. In this study, the entry rate of PL into the fetal circulation was estimated by injection of 125I-labelled ovine PL into two mid- and four late-gestation fetuses. At both ages, PL appears to be distributed into two body pools. One pool has a rapid half-life (approximately 9 min) and a volume of distribution approximately 8% of body weight, while the second pool has a longer half-life (approximately 45 min) and a distribution volume only 4% of body weight. The first pool is presumably blood plasma, but the physiological identity of the second pool is unknown. The effective half-life of PL is approximately 15 min, and the liver is suggested as a probable major site of degradation. These estimates were confirmed in late gestation by measuring fetal plasma concentrations of PL in response to a continuous infusion of unlabelled PL. The kinetic parameters estimated in this study can be used to determine the quantity of exogenous hormone required to alter PL concentration in fetal plasma in a predictable manner.