Peshin J, Ornoy A, Menczel J
Isr J Med Sci. 1976 Mar;12(3):248-56.
Pregnant rats were treated with 44, 88 and 176 Medical Research Council munits of thyrocalcitonin (TCT) twice daily during days 10 to 21 of gestation. Nonpregnant rats received the same treatment for 12 days. Administration of TCT to the pregnant rats increased the ash and calcium content of fetal bones and decreased the phosphorus content. The diaphyses were short and contained many persisting enchondral trabeculae and a reduced number of osteoclasts. TCT reduced the fetal intestinal alkaline phosphatase activity but elevated the intestinal calcium-binding protein content. In the pregnant and nonpregnant rats, treatment with TCT resulted in hypocalcemia and hypophosphatemia, and increased the calcium-binding protein content of the duodenal mucosa. In the fetuses, the calcium-binding protein content and alkaline phosphatase activity were higher in the jejunum and ileum than in the duodenum, and were much higher than the values found in adult animals. Our findings indicate that TCT passes through the rat placenta and affects the fetal skeleton and calcium metabolism directly, resulting primarily in decreased bone resorption.
在妊娠第10至21天，给怀孕大鼠每日两次注射44、88和176医学研究委员会单位的甲状腺降钙素（TCT）。未怀孕大鼠接受相同治疗12天。给怀孕大鼠注射TCT会增加胎儿骨骼的灰分和钙含量，并降低磷含量。骨干短小，含有许多持续存在的软骨内小梁，破骨细胞数量减少。TCT降低了胎儿肠道碱性磷酸酶活性，但提高了肠道钙结合蛋白含量。在怀孕和未怀孕大鼠中，TCT治疗导致低钙血症和低磷血症，并增加了十二指肠黏膜的钙结合蛋白含量。在胎儿中，空肠和回肠中的钙结合蛋白含量和碱性磷酸酶活性高于十二指肠，且远高于成年动物中的值。我们的研究结果表明，TCT可穿过大鼠胎盘并直接影响胎儿骨骼和钙代谢，主要导致骨吸收减少。
