Amino acid composition of parturient plasma, the intervillous space of the placenta and the umbilical vein of term newborn infants
Braz. j. med. biol. res
; 37(5): 711-717, May 2004. ilus, tab
Article
in English
| LILACS
| ID: lil-357545
Responsible library:
BR1.1
RESUMO
The objective of the present study was to determine the levels of amino acids in maternal plasma, placental intervillous space and fetal umbilical vein in order to identify the similarities and differences in amino acid levels in these compartments of 15 term newborns from normal pregnancies and deliveries. All amino acids, except tryptophan, were present in at least 186 percent higher concentrations in the intervillous space than in maternal venous blood, with the difference being statistically significant. This result contradicted the initial hypothesis of the study that the plasma amino acid levels in the placental intervillous space should be similar to those of maternal plasma. When the maternal venous compartment was compared with the umbilical vein, we observed values 103 percent higher on the fetal side which is compatible with currently accepted mechanisms of active amino acid transport. Amino acid levels of the placental intervillous space were similar to the values of the umbilical vein except for proline, glycine and aspartic acid, whose levels were significantly higher than fetal umbilical vein levels (average 107 percent higher). The elevated levels of the intervillous space are compatible with syncytiotrophoblast activity, which maintain high concentrations of free amino acids inside syncytiotrophoblast cells, permitting asymmetric efflux or active transport from the trophoblast cells to the blood in the intervillous space. The plasma amino acid levels in the umbilical vein of term newborns probably may be used as a standard of local normality for clinical studies of amino acid profiles.
Full text:
Available
Collection:
International databases
Database:
LILACS
Main subject:
Umbilical Veins
/
Chorionic Villi
/
Amino Acids
/
Maternal-Fetal Exchange
Limits:
Female
/
Humans
/
Male
/
Infant, Newborn
/
Pregnancy
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2004
Document type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade de São Paulo/BR