Delorme A C, Marche P, Garel J M
J Dev Physiol. 1979 Jun;1(3):181-94.
During the perinatal period, calcium metabolism is stressed. As intestinal Ca-binding protein is considered as a molecular expression of the hormonal effect of 1,25-dihydroxycholecalciferol (1,25(OH)2D3), Ca-binding protin measurements may document the vitamin D roles during this period. We describe the variations of Ca-binding protein concentrations in the rat during the last 5 days of gestation, in the maternal duodenum, placentas, fetal membranes and fetal intestines. We also report intestinal Ca-binding protein changes from birth until weaning. The evolution of the maternal intestinal Ca-binding protein, which increases on day 19.5 of gestation, is consistent with that of calcium intestinal absorption and may be explained by increased 1,25(OH)2D3 production. Placental Ca-binding protein rises from day 17.5 until the end of gestation, and may be related to the profile of calcium transfer from mother to fetuses. It is noteworthy that the placental Ca-binding protein is predominantly found in the fetal part of the organ where materno-fetal exchanges occur. The yolk sac synthesizes substantial amounts of Ca-binding protein. In the fetal membranes, Ca-binding protein plateaus from day 17.5 until day 20.5 and decreases on day 21.5. The Ca-binding protein presence in the fetal placenta and in the yolk sac may suggest that these tissues are also targets for vitamin D. In the fetus the intestinal Ca-binding protein s is detected as early as day 17.5 of gestation and increases markedly during the last day of gestation. From birth and during the first 3 weeks of postnatal life, the intestinal Ca-binding protein concentration does not change. It undergoes a sharp rise just at the time of weaning. We have also shown that the specific distribution of Ca-binding protein along the intestine is acquired during intrauterine life and does not change with sucking or weaning. The two main changes of intestinal Ca-binding protein, observed just before birth and at weaning, may reflect the intestinal maturation and/or variations in vitamin D metabolism.
在围产期，钙代谢面临压力。由于肠钙结合蛋白被视为1,25 - 二羟胆钙化醇（1,25(OH)₂D₃）激素作用的分子表达，测量钙结合蛋白可能有助于揭示该时期维生素D的作用。我们描述了妊娠最后5天大鼠母体十二指肠、胎盘、胎膜和胎儿肠道中钙结合蛋白浓度的变化。我们还报告了从出生到断奶期间肠道钙结合蛋白的变化。母体肠道钙结合蛋白在妊娠第19.5天增加，其变化与肠道钙吸收一致，可能是由于1,25(OH)₂D₃生成增加所致。胎盘钙结合蛋白从第17.5天开始升高直至妊娠结束，可能与钙从母体向胎儿的转运情况有关。值得注意的是，胎盘钙结合蛋白主要存在于发生母胎物质交换的器官的胎儿部分。卵黄囊合成大量钙结合蛋白。在胎膜中，钙结合蛋白从第17.5天到第20.5天保持稳定，在第21.5天下降。胎儿胎盘和卵黄囊中存在钙结合蛋白可能表明这些组织也是维生素D的作用靶点。在胎儿中，早在妊娠第17.5天就可检测到肠道钙结合蛋白，在妊娠最后一天显著增加。从出生到出生后3周，肠道钙结合蛋白浓度没有变化。在断奶时会急剧上升。我们还表明，钙结合蛋白沿肠道的特定分布在子宫内生活期间就已形成，不会因吸吮或断奶而改变。在出生前和断奶时观察到的肠道钙结合蛋白的两个主要变化，可能反映了肠道成熟和/或维生素D代谢的变化。
