Seki K, Wada S, Nagata N, Nagata I
Department of Obstetrics and Gynecology, National Defense Medical College, Saitama, Japan.
Gynecol Obstet Invest. 1994;37(2):83-6. doi: 10.1159/000292530.
To evaluate whether parathyroid hormone-related protein (PTHrP) plays any role in calcium metabolism during pregnancy and the perinatal period, we measured parathyroid hormone (PTH), immunoreactive PTHrP and calcium in maternal serum of women during pregnancy and puerperium, and in maternal and cord serum at delivery. Serum PTH levels in pregnant women were lower than those in nonpregnant women (p < 0.01). However, serum PTHrP levels were similar in the two groups of women. Cord serum total and ionic calcium levels were higher, and cord serum PTH levels were lower compared to maternal values (p < 0.01). Cord serum PTHrP levels were higher than maternal values, and umbilical arterial levels were higher than umbilical venous levels (p < 0.01). Higher levels of PTHrP in umbilical arterial blood than in umbilical venous blood suggest that the main source of cord blood PTHrP may be the fetus. PTHrP is reported to stimulate placental calcium transfer from mother to fetus in animals. The elevated cord blood PTHrP level in association with the decreased PTH level suggests that stimulation of placental calcium transfer by PTHrP may also be operative in humans.
为了评估甲状旁腺激素相关蛋白（PTHrP）在妊娠和围产期钙代谢中是否发挥作用，我们测定了妊娠和产褥期妇女母血中甲状旁腺激素（PTH）、免疫反应性PTHrP和钙的水平，以及分娩时母血和脐血中的这些指标。孕妇血清PTH水平低于非孕妇（p < 0.01）。然而，两组女性的血清PTHrP水平相似。与母血相比，脐血总钙和离子钙水平较高，而脐血PTH水平较低（p < 0.01）。脐血PTHrP水平高于母血，且脐动脉水平高于脐静脉水平（p < 0.01）。脐动脉血中PTHrP水平高于脐静脉血，这表明脐血PTHrP的主要来源可能是胎儿。据报道，PTHrP可刺激动物胎盘将钙从母体转运至胎儿。脐血PTHrP水平升高而PTH水平降低表明，PTHrP对胎盘钙转运的刺激作用在人类中可能也起作用。
