Kanzaki Y, Obara H, Yoshioka T
Acta Obstet Gynecol Scand. 1977;56(5):459-61. doi: 10.3109/00016347709155011.
Alkaline phosphatase was brought into solution from microsomal fractions of placentas of varying gestational age by using gradually increasing concentrations of proteinase papain. When the activity of the soluble alkaline phosphatase (S) was compared with that of the non-soluble residue (R), the S/R ratio rose as pregnancy progressed. The electrophoretic pattern showed that in serum from pregnant women the papain-soluble alkaline phosphatase corresponded to the heat-stable one. These results indicate that the cytoplasmic membrane of the trophoblast changes with the growth of the placenta so that this enzyme is easily dissolved by papain. It is probable that alkaline phosphatase molecules easily enter the maternal blood stream in late pregnancy.
通过使用逐渐增加浓度的木瓜蛋白酶，从不同孕周胎盘的微粒体组分中提取出碱性磷酸酶。当将可溶性碱性磷酸酶（S）的活性与不溶性残渣（R）的活性进行比较时，随着妊娠进展，S/R比值升高。电泳图谱显示，孕妇血清中的木瓜蛋白酶可溶性碱性磷酸酶与热稳定的碱性磷酸酶相对应。这些结果表明，滋养层细胞膜随胎盘生长而变化，使得这种酶易于被木瓜蛋白酶溶解。在妊娠后期，碱性磷酸酶分子很可能容易进入母体血流。
