Effect of adrenomedullin on placental and ovarian function

肾上腺髓质素（AM）是近年来从人嗜铬细胞瘤中分离到的一种新的血管舒张肽。AM被发现可以调节心血管系统，这表明AM在控制孕妇的血流方面也具有重要作用。本研究的目的是探讨AM可能参与人类母体循环和胎盘功能在怀孕期间。妊娠期母体血浆循环和胎盘功能中的AM浓度采用放射免疫分析法（RIA），用抗人AM兔血清测定孕妇血浆中AM浓度。母体血浆中的免疫反应性（ir）-AM水平在孕早期为3.4 * 0.7 fmol/ml（平均值 * SEM），孕中期为3.3 * 1.1，孕晚期为7.3 * 2.8。4.1* 产后早期为1.9，非妊娠期为3.0 * 0.4。孕晚期Ir-AM水平显著高于其他各期。血浆雌二醇（E2）、孕酮浓度。(P)用放免法测定人胎盘催乳素（hPL）和人绒毛膜促性腺激素（hCG）。本研究采用免疫组化和北方印迹法检测胎盘组织中AM的表达，探讨AM与胎盘功能的关系。以克隆的人AM互补DNA为探针，发现AM在足月羊膜中的免疫组化定位及AM mRNA在人胎盘组织中的表达，证实了AM在妊娠期母体血浆中的免疫反应性，提示AM在母体循环和胎盘发育中具有AM的生理功能。

Adrenomedullin (AM) is a noved vasolelaxtant peptide recently isolated from human phenochromocytoma. AM is found to regulate the cardiovascular system, suggesting that AM has also an important role in the control of blood flow in pregnant women. The present study was undertaken to investigate the possible involvement of AM in human maternal circulation and in placental function during pregnancy. AM concentrations in maternal plasma circulation and in placental function during pregnancy. AM concentrations in maternal plasma were measured by a highly sensitive and specific radioimmunoassay (RIA) for AM using anti-human AM rabbit serum. Immunoreactive (ir)-AM levels in maternal plasma were 3.4 * 0.7 fm ol/mI (mean * SEM) in the first trimester, 3.3 * 1.1 in the second trimester, 7.3 * 2.8 in the third trimester. 4.1 * 1.9 in early puerperium and 3.0 * 0.4 in non-pregnant periods. Ir-AM level in the third trimester was significantly greater than those in other periods. Plasma concentrations of estradio1 (E2), progesterone .(P), human placental lactogen (hPL) and human chorionic gonadotropin (hCG) were also measured by RIA kits. Significant correlations have been demonstrated between the concentrations of ir-AM and those of E2, P.IIPL.So we examined the expression of AM at placenta by using immunohistochemistry and Northern blot analysis in order to demonstrate the correlation between AM and placental function. We found the immunohisrochemical location of AM in the amnion at term and the expression of AM mRNA in human placental tissues using cloned human AM complementary DNA as probe.The present study is the report demonstrating the immunoreactivity of hAM in maternal plasma during pregnancy, and suggesting the AM possesses the physiologic functions of AM in the maternal circulation and in the development of placenta.