Kawada A, Kudo T, Kishimoto Y
Asia Oceania J Obstet Gynaecol. 1989 Sep;15(3):291-8. doi: 10.1111/j.1447-0756.1989.tb00191.x.
The concentrations of L-dopa, three catecholamines and 3,4-dihydroxyphenylacetic acid (DOPAC) were measured both in the amniotic fluid and the fetal urine obtained at term elective cesarean section, using high performance liquid chromatography with electrochemical detection. Dopamine was the major compound in the fetal urine, while DOPAC predominated in the amniotic fluid. Monoamine oxidase (MAO) activity was detected in the fetal membranes by the method of Wurthman and Axelrod. MAO activities in the amnion, chorion and decidua were 0.023 +/- 0.003, 0.180 +/- 0.05 and 2.69 +/- 0.66 nmol/mg protein/min (mean +/- SE), respectively. Incubation experiments, using fetal membranes with human amniotic fluid, demonstrated that dopamine in amniotic fluid was metabolized to DOPAC by fetal membranes. Additional incubation experiments with pargyline, a MAO inhibitor, showed that it strongly inhibited the conversion of dopamine into DOPAC. These results suggest that the dopamine in amniotic fluid was metabolized to DOPAC by MAO in the fetal membranes. This mechanism may regulate the dopamine concentration in amniotic fluid.
采用高效液相色谱电化学检测法，对足月选择性剖宫产时获取的羊水和胎儿尿液中左旋多巴、三种儿茶酚胺及3,4 - 二羟基苯乙酸（DOPAC）的浓度进行了测定。多巴胺是胎儿尿液中的主要化合物，而DOPAC在羊水中占主导地位。采用Wurthman和Axelrod的方法检测了胎膜中的单胺氧化酶（MAO）活性。羊膜、绒毛膜和蜕膜中的MAO活性分别为0.023±0.003、0.180±0.05和2.69±0.66 nmol/mg蛋白质/分钟（平均值±标准误）。用人羊水的胎膜进行孵育实验表明，羊水中的多巴胺被胎膜代谢为DOPAC。用MAO抑制剂帕吉林进行的额外孵育实验表明，它强烈抑制多巴胺向DOPAC的转化。这些结果提示，羊水中的多巴胺被胎膜中的MAO代谢为DOPAC。该机制可能调节羊水中的多巴胺浓度。
