Fernandes-Costa F, Metz J
Br J Haematol. 1979 Dec;43(4):625-30. doi: 10.1111/j.1365-2141.1979.tb03795.x.
Transcobalamins I, II and III (TCI, TCII, TCIII) were purified from human serum, saturated with 57Co-vitamin B12 (57Co-B12), and injected into pregnant rabbits. Whole body retention of the 57Co-B12 averaged 91% and was similar for each of the three vitamin B12 binders. A maximum of 62% of the injected 57Co-B12 was found in fetal tissues when the vitamin was injected bound to TCII, but only 6--7% when bound to TCI or TCIII. Thus TCII is responsible for the delivery of vitamin B12 to the fetus.
从人血清中纯化出钴胺素I、II和III（TCI、TCII、TCIII），用57钴 - 维生素B12（57Co - B12）饱和后，注射到怀孕兔子体内。57Co - B12在全身的保留率平均为91%，三种维生素B12结合蛋白的保留率相似。当维生素与TCII结合注射时，在胎儿组织中发现最多62%的注射57Co - B12，但与TCI或TCIII结合时仅为6 - 7%。因此，TCII负责将维生素B12输送到胎儿体内。
