Sekizawa A, Ishikawa H, Morimoto T, Hirose K, Suzuki A, Saito H, Yanaihara T, Arai Y, Oguchi K
Department of Obstetrics and Gynecology, School of Medicine, Showa University, Tokyo, Japan.
Acta Obstet Gynecol Scand. 1996 May;75(5):423-7. doi: 10.3109/00016349609033347.
To study the role of decidual monoamine oxidase (MAO)-A and -B activities before delivery, the relationship between MAO activity in fetal membranes and catecholamine (CA) concentration in amniotic fluid (AF) was determined.
Fetal membranes and AF were obtained at the time of elective Cesarean section (CS group, n = 11) and Cesarean section due to fetal distress without labor pains (FD group, n = 5). MAO-A and -B activities were radiometrically measured using 14C-5-hydroxytriptamine for MAO-A substrate and 14C-benzylamine for MAO-B substrate. CA concentrations in AF were measured by high performance liquid chromatograph with an electro-chemical detector.
Both MAO-A and -B activities in decidua obtained from CS were significantly lower than those obtained from FD. Both norepinephrine (NE) and epinephrine (EP) concentrations were significantly lower in the CS group than the FD group. A significant positive correlation between decidual MAO-A activity and NE concentration in AF was observed. No significant correlation was observed between MAO-B activity and the concentration of NE in AF. There was no correlation between EP concentrations and MAO activities.
These results suggest that CA concentration in AF may be related to the activity of MAO in fetal membranes, determined by certain physiological processes during pregnancy. It has been suggested that metabolism of monoamines in fetal membranes also plays an important role in reducing monoamine influx into maternal myometrium from the AF.
为研究分娩前蜕膜单胺氧化酶（MAO）-A和-B活性的作用，确定胎膜中MAO活性与羊水（AF）中儿茶酚胺（CA）浓度之间的关系。
在择期剖宫产时获取胎膜和羊水（CS组，n = 11）以及因胎儿窘迫行剖宫产且无宫缩时获取胎膜和羊水（FD组，n = 5）。使用14C-5-羟色胺作为MAO-A底物、14C-苄胺作为MAO-B底物，通过放射测定法测量MAO-A和-B活性。采用高效液相色谱仪电化学检测器测量AF中的CA浓度。
CS组蜕膜中的MAO-A和-B活性均显著低于FD组。CS组去甲肾上腺素（NE）和肾上腺素（EP）浓度均显著低于FD组。观察到蜕膜MAO-A活性与AF中NE浓度之间存在显著正相关。未观察到MAO-B活性与AF中NE浓度之间存在显著相关性。EP浓度与MAO活性之间无相关性。
这些结果表明，AF中的CA浓度可能与胎膜中MAO的活性有关，这由孕期特定生理过程决定。有人提出，胎膜中单胺的代谢在减少单胺从AF流入母体子宫肌层方面也起重要作用。
