Di Iorio R, Marinoni E, Letizia C, Alò P, Villaccio B, Poverini R, Cosmi E V
Laboratory of Perinatal Medicine and Molecular Biology, 2nd Institute of Obstetrics and Gynecology, University La Sapienza, Rome, Italy.
Am J Obstet Gynecol. 2001 Sep;185(3):697-702. doi: 10.1067/mob.2001.117189.
Circulating adrenomedullin is increased in pregnancy, and placental and fetal membranes participate significantly in its secretion. Recent studies have suggested a potential role for this peptide in the regulation of fetoplacental circulation and placental hormonal secretion. Because adrenomedullin acts also as a uterorelaxant in rats, this study was designed to investigate whether fetoplacental adrenomedullin production changes with human labor, either at term or preterm.
Eighty pregnant women grouped according to gestational age and presence of labor were studied. Adrenomedullin concentrations in plasma, amniotic fluid, and placental tissue extracts were measured by means of radioimmunoassay and immunohistochemistry. In addition, the ability of amnion and chorion-decidua to secrete adrenomedullin was investigated in vitro.
Adrenomedullin concentrations in amniotic fluid were higher in preterm labor, whereas no differences were found in adrenomedullin expression or concentrations in tissues or in maternal and fetal plasma between vaginal delivery or elective cesarean section, both at term and preterm. During term labor (8 patients), maternal plasma adrenomedullin concentration decreased with advancing cervical dilatation, being 173 pg/mL at the beginning of the active stage of labor and 57 pg/mL at the time of delivery. Adrenomedullin concentration in the medium of amnion- and chorion-decidua-cultured cells was higher after vaginal delivery.
These results suggest that a decrease in adrenomedullin production is not involved in the onset of labor in human subjects but rather that it may play a role other than that of a myometrial relaxant in human parturition.
孕期循环中的肾上腺髓质素水平升高，胎盘和胎膜在其分泌中起重要作用。最近的研究表明，这种肽在调节胎儿 - 胎盘循环和胎盘激素分泌方面可能发挥作用。由于肾上腺髓质素在大鼠中也作为子宫松弛剂起作用，本研究旨在调查足月或早产时胎儿 - 胎盘肾上腺髓质素的产生是否随分娩而变化。
对80名根据孕周和分娩情况分组的孕妇进行了研究。通过放射免疫测定和免疫组织化学方法测量血浆、羊水和胎盘组织提取物中的肾上腺髓质素浓度。此外，还在体外研究了羊膜和绒毛膜 - 蜕膜分泌肾上腺髓质素的能力。
早产时羊水中的肾上腺髓质素浓度较高，而在足月和早产时，阴道分娩或择期剖宫产之间的组织、母体和胎儿血浆中的肾上腺髓质素表达或浓度均未发现差异。在足月分娩期间（8例患者），母体血浆肾上腺髓质素浓度随着宫颈扩张而降低，在活跃分娩期开始时为173 pg/mL，分娩时为57 pg/mL。阴道分娩后，羊膜和绒毛膜 - 蜕膜培养细胞培养基中的肾上腺髓质素浓度较高。
这些结果表明，肾上腺髓质素产生的减少与人类分娩的发动无关，而是可能在人类分娩中发挥除子宫肌层松弛剂之外的其他作用。
