Dawood M Y, Lauersen N H, Trivedi D, Ylikorkala O, Fuchs F
Acta Endocrinol (Copenh). 1979 Aug;91(4):704-18. doi: 10.1530/acta.0.0910704.
Oxytocin was determined by radioimmunoassay in pregnant baboons throughout gestation, in the foetus at caesarean section, and after oxytocin infusion into the mother and foetus. Serial maternal plasma oxytocin in 6 baboons during pregnancy showed a significant correlation between the gestational age and maternal plasma oxytocin concentrations with a correlation coefficient of r = 0.3185 and P less than 0.005. Seventy-one out of 75 plasma samples (94.7%) during pregnancy had detectable levels of oxytocin. Uterine vein plasma had higher oxytocin concentrations than maternal plasma and amniotic fluid (18.6 +/- 4.6 pg/ml; mean +/0 SE) but lower than umbilical, jugular vein and cardiac blood from the foetus. Foetal pituitary gland contained 5.4--26.1 micrograms oxytocin/g. Regular uterine contractions were established with iv oxytocin of 4--20 mU/min and the plasma oxytocin measured showed a significant correlation with the uterine activity achieved (r = 0.64, P less than 0.001). The disappearance of plasma oxytocin at 179 days gestation gave an apparent half-life of 1.1 and 1.7 min in 2 baboons with a late half-life of 9.9 and 17.3 min, respectively. In one baboon at 171 days gestation, the apparent half-life of oxytocin was 9.9 min. The metabolic clearance rates were calculated to be 3.1, 3.2 and 11.7 ml/kg/min, respectively. The production rates were 97, 74, 390 pg/kg/min, respectively. Oxytocin injected into the umbilical vessel near term showed an increase in oxytocin concentration in maternal and uterine vein plasma and amniotic fluid, suggesting that oxytocin can cross the placenta from the foetal to the maternal side. Our findings indicate that in the baboon (1) oxytocin is present throughout pregnancy, (2) uterine activity can be correlated with plasma oxytocin during oxytocin infusion, (3) foetal circulation has higher oxytocin concentration than maternal blood and (4) oxytocin probably can cross the placenta from the foetus to the mother.
在整个妊娠期对妊娠狒狒进行放射免疫测定来检测催产素，在剖宫产时检测胎儿体内的催产素，并在向母体和胎儿输注催产素后进行检测。6只狒狒在孕期的系列母体血浆催产素显示，孕周与母体血浆催产素浓度之间存在显著相关性，相关系数r = 0.3185，P小于0.005。孕期75份血浆样本中有71份（94.7%）可检测到催产素水平。子宫静脉血浆中的催产素浓度高于母体血浆和羊水（18.6±4.6 pg/ml；均值±标准误），但低于胎儿的脐血、颈静脉血和心脏血。胎儿垂体中催产素含量为5.4 - 26.1微克/克。静脉注射4 - 20 mU/min的催产素可引发规律的子宫收缩，所测血浆催产素与所达到的子宫活动显著相关（r = 0.64，P小于0.001）。在妊娠179天时，血浆催产素的消失在2只狒狒中给出的表观半衰期分别为1.1分钟和1.7分钟，晚期半衰期分别为9.9分钟和17.3分钟。在一只妊娠171天的狒狒中，催产素的表观半衰期为9.9分钟。计算出的代谢清除率分别为3.1、3.2和11.7 ml/kg/min。产生率分别为97、74、390 pg/kg/min。在接近足月时向脐血管注射催产素后，母体和子宫静脉血浆以及羊水中的催产素浓度升高，这表明催产素能够从胎儿侧穿过胎盘到达母体侧。我们的研究结果表明，在狒狒中：（1）整个孕期都存在催产素；（2）在输注催产素期间子宫活动与血浆催产素相关；（3）胎儿循环中的催产素浓度高于母体血液；（4）催产素可能能从胎儿穿过胎盘到达母体。
