Cobalamin binding proteins in the human fetus.
Cobalamin binding proteins are synthesized by the fetus from at least 16-19 gestational weeks. Cerebrospinal fluid contained transcobalamin with size and isoelectric points identical to adult transcobalamin. The unsaturated cobalamin-binding capacity in the fetal cerebrospinal fluid was comparable to adult levels, that is 0.01-0.04 nmol/l, median 0.03 nmol/l, n = 4. The unsaturated cobalamin-binding capacity in serum was low compared to adult values (0.02-0.04 nmol/l, median 0.03 nmol/l, n = 4). The unsaturated cobalamin-binding capacity in at term umbilical cord serum was alike for arterial and venous blood. The values obtained was 0.14-1.03 nmol/l, median 0.66 nmol/l, n = 22, which was two thirds of the corresponding values in maternal serum: In the amniotic fluid haptocorrin, intrinsic factor and transcobalamin were identical with the adult binders regarding the size and the isoelectric point.
Hansen
M
M
Department of Medicine and Haematology, Gentofte Hospital, University of Copenhagen, Denmark.
Høgdall
C K
CK
Kryger-Baggesen
N
N
D005333:Fetus / Q000502:physiology*; D006801:Humans; D007526:Isoelectric Point; D008970:Molecular Weight; D014155:Transcobalamins / Q000097:blood / Q000134:cerebrospinal fluid / Q000502:physiology*; D014805:Vitamin B 12 / Q000378:metabolism
D014155:Transcobalamins; D014805:Vitamin B 12