Sasaki A, Shinkawa O, Yoshinaga K
Department of Internal Medicine, Wakayanagi Hospital, Miyagi Prefecture, Japan.
J Clin Invest. 1989 Dec;84(6):1997-2001. doi: 10.1172/JCI114390.
To clarify the physiological role of placental corticotropin-releasing hormone (CRH), we measured plasma CRH, ACTH, and cortisol throughout pregnancy. Cerebrospinal fluid (CSF) CRH levels and ACTH responsiveness to synthetic CRH were also quantified in pregnant and nonpregnant women. Maternal plasma CRH levels, which increased progressively during pregnancy, correlated well with both ACTH and cortisol in early labor, delivery, and postpartum samples, and also with cortisol levels in samples before labor. CSF CRH levels in term pregnant women did not differ from those of nonpregnant women. CRH infusion that attained similar plasma CRH levels to those found in late pregnancy elicited significant ACTH release in vivo and regular CRH test provoked normal ACTH response during early pregnancy but no response during late pregnancy. We concluded that: (a) maternal pituitary-adrenal axis correlates well with plasma CRH levels, which are high enough to provoke ACTH release from maternal pituitary; (b) hypothalamic CRH secretion in term pregnant women is not exaggerated; and (c) maternal pituitary is responsive to synthetic CRH in early but not late pregnancy, suggesting that maternal pituitary-adrenal axis is already activated by high circulating CRH. Placental CRH may be an important stimulator of the maternal pituitary-adrenal axis during pregnancy.
为阐明胎盘促肾上腺皮质激素释放激素（CRH）的生理作用，我们在整个孕期测量了血浆CRH、促肾上腺皮质激素（ACTH）和皮质醇水平。还对孕妇和非孕妇的脑脊液（CSF）CRH水平以及ACTH对合成CRH的反应性进行了定量分析。孕期母体血浆CRH水平逐渐升高，在分娩早期、分娩时及产后样本中与ACTH和皮质醇均显著相关，在分娩前样本中也与皮质醇水平相关。足月孕妇的脑脊液CRH水平与非孕妇无差异。静脉输注CRH使血浆CRH水平达到妊娠晚期水平时，可在体内引起显著的ACTH释放，常规CRH试验在妊娠早期可诱发正常的ACTH反应，但在妊娠晚期无反应。我们得出以下结论：（a）母体垂体-肾上腺轴与血浆CRH水平显著相关，血浆CRH水平足以促使母体垂体释放ACTH；（b）足月孕妇下丘脑CRH分泌并未增加；（c）母体垂体在妊娠早期对合成CRH有反应，但在妊娠晚期无反应，提示母体垂体-肾上腺轴已被循环中高水平的CRH激活。胎盘CRH可能是孕期母体垂体-肾上腺轴的重要刺激物。
