van Bogaert E C, Gueuning C O, Graff G L
Arch Int Physiol Biochim. 1981 Nov;89(4):303-12. doi: 10.3109/13813458109069480.
Net transfer of 31P and 32P inorganic phosphate form the maternal plasma to the rat chorio-allantoic placenta has been studied after intraperitoneal injection of [32P] ortho-phosphate in primigravid females at the 12th day or late stages of gestation. The concentration and label uptake per unit weight of placenta of the inorganic phosphate (Pi), organic-bound acid-soluble phosphate (POAS) and organic-bound acid-insoluble phosphate (POAIS) fractions are negatively correlated with increasing placental weight, whereas their specific activities are independent of placental weight. The amount and label uptake per whole placenta of the Pi, POAS and POAIS fractions are positively correlated with increasing placental weight. The placental concentrations of inorganic phosphate and calcium are positively related without, however, any marked accumulation of calcium. The growing placenta is thus shown to reduce progressively, on a unit weight basis, both the inorganic phosphate uptake from the maternal plasma and its further incorporation into organic-bound fractions. There is no evidence of a control by the foetal weight, acting per se, on these placental activities.
在妊娠第12天或妊娠后期，给初产雌性大鼠腹腔注射[32P]正磷酸盐后，研究了31P和32P无机磷酸盐从母体血浆向大鼠绒毛尿囊胎盘的净转运。胎盘单位重量的无机磷酸盐（Pi）、有机结合酸溶性磷酸盐（POAS）和有机结合酸不溶性磷酸盐（POAIS）部分的浓度和标记摄取量与胎盘重量增加呈负相关，而它们的比活性与胎盘重量无关。Pi、POAS和POAIS部分的总量和整个胎盘的标记摄取量与胎盘重量增加呈正相关。无机磷酸盐和钙的胎盘浓度呈正相关，然而，钙没有明显的积累。因此，生长中的胎盘在单位重量基础上逐渐减少从母体血浆中摄取的无机磷酸盐及其进一步掺入有机结合部分。没有证据表明胎儿体重本身对这些胎盘活动有控制作用。
