Ogino M, Kinoshita K, Satoh K, Mizuno M, Sakamoto S
Endocrinol Jpn. 1983 Oct;30(5):631-5. doi: 10.1507/endocrj1954.30.631.
The present study was undertaken to assess the metabolism of radiolabeled pregnenolone in the placenta throughout pregnancy in organ culture. The product generated from pregnenolone was only progesterone regardless of the weeks of gestation. The amount of progesterone formed by the placenta was 5.60 +/- 0.15 x 10(-11) moles/mg protein/hour in the 1st trimester (n = 4), 6.47 +/- 0.09 x 10(-11) moles/mg protein/hour in the 2nd trimester (n = 3) and 7.72 +/- 0.25 x 10(-11) moles/mg protein/hour in the 3rd trimester (n = 6). The increase in the formation of progesterone as gestation advanced was statistically significant. The increase in the placental weight throughout pregnancy was in proportion to the rise in maternal plasma levels of progesterone. These data indicate that the manifold increase in progesterone in the maternal circulation as gestation advances mainly reflects the increase in the functional mass of the placenta rather than the increased rate of production of progesterone in the placenta.
本研究旨在通过器官培养评估整个孕期胎盘内放射性标记孕烯醇酮的代谢情况。无论妊娠周数如何，孕烯醇酮产生的产物均仅为孕酮。胎盘产生孕酮的量在孕早期为5.60±0.15×10⁻¹¹摩尔/毫克蛋白/小时（n = 4），孕中期为6.47±0.09×10⁻¹¹摩尔/毫克蛋白/小时（n = 3），孕晚期为7.72±0.25×10⁻¹¹摩尔/毫克蛋白/小时（n = 6）。随着妊娠进展孕酮生成量的增加具有统计学意义。整个孕期胎盘重量的增加与母体血浆孕酮水平的升高成比例。这些数据表明，随着妊娠进展母体循环中孕酮大量增加主要反映了胎盘功能质量的增加，而非胎盘孕酮产生速率的提高。
