Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-6-3
pubmed:abstractText
A rat model was used to investigate whether high oral doses of vitamin A lead to fetal malformations and to what extent retinyl esters (RES) are transferred from the mother to the fetuses. Retinol and RES concentrations in plasma behave similarly in rats and humans. When high concentrations of vitamin A are administered, plasma retinol concentrations remain relatively constant, whereas plasma RES increased in parallel with the dose. To achieve an elevation from approximately 150 to > 1525 nmol x L(-1) in the experimental group before mating, female Ibm: RORO (spf) rats were fed a maintenance diet enriched with 15.2 x 10(3) retinol equivalents (RE) x kg(-1) at the start and increased stepwise to 52.5 x 10(3) for a total of 8 mo. A parallel subgroup was maintained to measure progress in experimental rats without interference by blood taking. Rats of the control group received the basal diet analyzed to contain 4.5 x 10(3) RE x kg(-1). Before mating the mean body weights of experimental and control rats were not significantly different. All-trans, 13-cis, 4-oxo-all-trans and 5,6-epoxy-all-trans retinoic acid (RA) concentrations were determined in maternal and fetal plasma. With high vitamin A intake, 4-oxo- and 5,6-epoxy RA concentrations were significantly higher in the fetuses than in their mothers. Although these high intakes of vitamin A by the rat dams resulted in high maternal and fetal plasma concentrations of vitamin A and its metabolites, fetal malformations were not observed. This may be due to the fact that circulating RES are not teratogenic and that after crossing the placental barrier, they are stored mainly in fetal liver.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-3166
pubmed:author
pubmed:issnType
Print
pubmed:volume
126
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
973-83
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Long-term administration of high dose vitamin A to rats does not cause fetal malformations: macroscopic, skeletal and physicochemical findings.
pubmed:affiliation
Department of Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't