Prenatal aspects of ascorbic acid metabolism in the albino rat.

Transfer of ascorbic acid and/or its derivatives from maternal blood into the fetus was studied during the last week of gestation in the rat. Rats were injected intravenously with [1-14C]-ascorbic acid and the rate of transfer estimated by the concentration and content of label present in placentas and fetuses. At all times studied the concentration of label in the placenta was greater than in the fetus. The highest capacity of the placenta to concentrate label was found on day 15 decreasing to a low at day 19 and again increasing up to day 21. While in the fetuses, the concentration of label per gram of tissue remained remarkably constant throughout the study. The quantity of labeled compounds transferred into the fetus per gram of placental tissue increased between day 15 and day 21 of gestation.