Tabei T, Ochiai K, Terashima Y, Takanashi N
Department of Obstetrics and Gynecology, Sekishindo Hospital, Kawagoe, Japan.
Am J Obstet Gynecol. 1991 Mar;164(3):896-900. doi: 10.1016/0002-9378(91)90536-z.
Inhibin levels were measured by a double antibody heterologous radioimmunoassay in the peripheral serum of 75 pregnant women throughout gestation and in serum from the umbilical vein and artery, which was obtained at the time of delivery. For reference, samples were obtained from 20 nonpregnant women in the early (days 0 to 3), mid (days 4 to 8), and late (days 9 to 14) luteal or follicular phase. Maternal serum levels of inhibin (mean +/- SEM) in early (6 to 12 weeks) gestation (36.4 +/- 2.6 U/ml, n = 36) were significantly (p less than 0.01) higher than those in serum from nonpregnant women in the mid (23.9 +/- 2.5 U/ml, n = 19) or late (11.3 +/- 0.6 U/ml, n = 19) luteal phase. Inhibin levels in maternal serum fell to 15.9 +/- 1.4 U/ml (n = 24) in mid (14 to 20 weeks) gestation and then gradually increased during late (21 to 40 weeks) gestation to peak levels of 49.4 +/- 5.1 U/ml (n = 9) at 36 to 37 weeks. Inhibin levels declined in parallel with human chorionic gonadotropin concentrations during the first trimester (r = 0.587 at p less than 0.01). Significant positive correlations (p less than 0.001) were observed between serum levels of inhibin and 17 beta-estradiol (r = 0.560), progesterone (r = 0.648), and human placental lactogen (r = 0.715) during mid and late (20 to 40 weeks) gestation. Inhibin levels in umbilical vein serum (38.5 +/- 1.3 U/ml, n = 5) were not different from those in umbilical artery serum (39.4 +/- 3.6 U/ml) but were significantly (p less than 0.01) lower than those in maternal serum (50.9 +/- 5.3 U/ml), which was obtained at the time of delivery. By day 5 of puerperium, serum levels of inhibin in the maternal vein were extremely low (2.3 +/- 0.1 U/ml, n = 7); these levels were nearly one fifth lower than follicular phase levels of 10.9 +/- 3.4 U/ml (n = 38). We propose that maternal inhibin in early gestation is secreted from the corpus luteum of pregnancy but that increasing inhibin levels during mid and late gestation result from inhibin that is produced by the placenta. The lack of an umbilical arterial-venous gradient for inhibin and the higher levels of inhibin in maternal serum argue against a fetal source of inhibin in the maternal circulation. The physiologic function of inhibin that is produced by the corpus luteum and by the placenta remains to be determined.
采用双抗体异源放射免疫分析法测定了75例孕妇整个孕期外周血清以及分娩时脐静脉和脐动脉血清中的抑制素水平。作为对照，采集了20例处于黄体期或卵泡期早期（第0至3天）、中期（第4至8天）和晚期（第9至14天）的非孕妇的样本。妊娠早期（6至12周）孕妇血清中抑制素水平（均值±标准误）为36.4±2.6 U/ml（n = 36），显著高于处于黄体期中期（23.9±2.5 U/ml，n = 19）或晚期（11.3±0.6 U/ml，n = 19）的非孕妇血清水平（p＜0.01）。妊娠中期（14至20周）孕妇血清中抑制素水平降至15.9±1.4 U/ml（n = 24），随后在妊娠晚期（21至40周）逐渐升高，在36至37周时达到峰值49.4±5.1 U/ml（n = 9）。妊娠早期，抑制素水平与人类绒毛膜促性腺激素浓度呈平行下降（r = 0.587，p＜0.01）。妊娠中期和晚期（20至40周），血清抑制素水平与17β - 雌二醇（r = 0.560）、孕酮（r = 0.648）和人胎盘催乳素（r = 0.715）之间存在显著正相关（p＜0.001）。脐静脉血清中抑制素水平（38.5±1.3 U/ml，n = 5）与脐动脉血清中抑制素水平（39.4±3.6 U/ml）无差异，但显著低于分娩时孕妇血清中抑制素水平（50.9±5.3 U/ml）（p＜0.01）。产后第5天，产妇静脉血清中抑制素水平极低（2.3±0.1 U/ml，n = 7）；这些水平比卵泡期水平10.9±3.4 U/ml（n = 38）低近五分之一。我们认为，妊娠早期孕妇体内的抑制素由妊娠黄体分泌，但妊娠中期和晚期抑制素水平升高是由胎盘产生的抑制素所致。抑制素在脐动脉 - 静脉中无梯度差异以及孕妇血清中抑制素水平较高，这表明母体循环中的抑制素并非来源于胎儿。由黄体和胎盘产生的抑制素的生理功能仍有待确定。
