ABSTRACT
Metabolism of [3H]-vitamin D3 in placenta and fetus liver of rats on the 20-21st day of pregnancy was investigated. Biosynthesis in vivo of 25-hydroxyvitamin D3 occurs in placenta and fetus liver and the maximum observed 25-hydroxylation composes 15% in placenta and 13% in the fetus liver. It has been shown, that C-25-hydroxylation of vitamin D3 in the microsomal and mitochondrial fractions of hepatocytes take place. It has been concluded that placenta and fetus liver, although to not very much degree, is able to realize vitamin D3 metabolism independent of mother's organism.
Subject(s)
Calcifediol/biosynthesis , Cholecalciferol/metabolism , Liver/metabolism , Placenta/metabolism , Animals , Female , Gestational Age , Liver/embryology , Microsomes, Liver/metabolism , Mitochondria, Liver/metabolism , Pregnancy , Rats , Rats, WistarABSTRACT
The exchange of vitamin D3 in the liver of pregnant rats has been studied. Incorporation of (3H)-vitamin D3 into the liver of pregnant rats on the 13th and 21st day of pregnancy made up 85% and 90% respectively of the intensity of absorption of the summary label by controlled animals. It is found that the period of exchange of (3H)-cholecalciferol in these animals increases with prolongation of pregnancy. The 25-hydroxylation of vitamin D3 in the liver of rats on the 13th and 21st day of pregnancy significantly decreases and makes up 30% and 50% of its hydroxylation in the nonpregnant rats.
Subject(s)
Cholecalciferol/metabolism , Liver/metabolism , Pregnancy, Animal/metabolism , Animals , Calcifediol/metabolism , Female , Hydroxylation , Pregnancy , Rats , Rats, WistarABSTRACT
Unilateral nephrectomy causes a decrease in provision of vitamin D dihydro derivatives in pregnant rats, which correlated with the development of hypocalcemia and hypophosphatemia as well as with an increased content of parathyroid hormone. Fetuses of these females contained less amount of mineral components and active metabolites of vitamin D. Neonates, being born by these females with the nephrectomy, had vitamin D deficiency, which was manifested as a decrease in content of active vitamin D metabolites and minerals as well as an increase in activity of alkaline phosphatase and in the content of parathyroid hormone.
