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The placental transport of [ 3 H] vitamin K 1 in rats
Author(s) -
Hamulyák Karly,
De Boervanden Berg Marian A. G,
Thijssen Henk H. W.,
Hemker H. Coenraad,
Vermeer Cees
Publication year - 1987
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1987.tb06863.x
Subject(s) - fetus , vitamin , medicine , microsome , endocrinology , pyruvate carboxylase , vitamin k deficiency , chemistry , biology , enzyme , pregnancy , biochemistry , genetics
Summary. In this paper we describe the placental transport of [ 3 H]vitamin K 1 in pregnant rats during the first 24 h after the oral administration of the vitamin. Vitamin K 1 in the fetal livers ranged from 0.13% (3 h) to 2% (24 h) of the values found in the corresponding maternal livers. In spite of the low placental transfer of vitamin K, we found no accumulation of coagulation factor precursors in the fetal rat liver microsomes as could be expected in vitamin K deficiency. Moreover, we could not demonstrate any difference between adult and fetal rat liver microsomes with regard to the sensitivity for warfarin. From these results we conclude that a substantial placental barrier exists for the transport of pharmacological amounts of vitamin K 1 but that under physiological conditions sufficient vitamin K 1 appears to be present in the fetal liver to ensure a full carboxylation reaction. The vitamin K‐dependent carboxylase activity rate of adult and fetal rat liver microsomes was comparable, indicating that the newborn rat has an adequate carboxylating system.