Itoh H, Sagawa N, Hasegawa M, Inamori K, Ueda H, Kitagawa K, Nanno H, Ihara Y, Kobayashi F, Mori T
Department of Gynecology and Obstetrics, Kyoto University Faculty of Medicine, Japan.
J Clin Endocrinol Metab. 1994 Jul;79(1):176-82. doi: 10.1210/jcem.79.1.8027223.
We previously reported the massive secretion of brain natriuretic peptide (BNP) from human amnion cells and suggested the possible role of BNP in the maintenance of human pregnancy. In this study, to elucidate the regulatory mechanism of BNP secretion from amnion cells, we measured the BNP level in the culture medium of amnion cells by RIA after incubation in the presence of various substances. Among the agents examined, cortisol (1 x 10(-7) to 1 x 10(-6) mol/L), dexamethasone (1 x 10(-8) to 1 x 10(-6) mol/L), and epidermal growth factor (EGF; 2 x 10(-11) to 2 x 10(-8) mol/L) inhibited BNP secretion from the cultured amnion cells in a dose-dependent manner. By contrast, transforming growth factor-beta (TGF beta; 4 x 10(-11) to 4 x 10(-9) mol/L) caused a 3- to 5-fold increase in BNP secretion. TGF beta-augmented BNP secretion was abolished by the addition of cortisol or EGF to the culture medium. Moreover, in this study, we revealed the presence of bioactive TGF beta in human amniotic fluid (approximately 4 x 10(-10) mol/L). The present finding of tight regulation of BNP secretion from amnion cells by cortisol, EGF and TGF beta, all at the concentrations physiologically present in human amniotic fluid, implies a physiological role of BNP secretion from amnion cells in the pregnant uterus.
我们先前报道了人脑膜细胞大量分泌脑钠肽（BNP），并提示BNP在维持人类妊娠中可能发挥的作用。在本研究中，为阐明羊膜细胞分泌BNP的调节机制，我们在各种物质存在的情况下孵育后，通过放射免疫分析法（RIA）测定了羊膜细胞培养基中的BNP水平。在所检测的试剂中，皮质醇（1×10⁻⁷至1×10⁻⁶mol/L）、地塞米松（1×10⁻⁸至1×10⁻⁶mol/L）和表皮生长因子（EGF；2×10⁻¹¹至2×10⁻⁸mol/L）以剂量依赖的方式抑制培养的羊膜细胞分泌BNP。相比之下，转化生长因子-β（TGF-β；4×10⁻¹¹至4×10⁻⁹mol/L）使BNP分泌增加3至5倍。向培养基中添加皮质醇或EGF可消除TGF-β增强的BNP分泌。此外，在本研究中，我们发现人羊水（约4×10⁻¹⁰mol/L）中存在生物活性TGF-β。目前发现，皮质醇、EGF和TGF-β在人羊水生理浓度下对羊膜细胞分泌BNP进行严格调控，这意味着羊膜细胞分泌BNP在妊娠子宫中具有生理作用。
