Tocopherol level in human fetal and infant liver.

Abstract

This investigation was undertaken to decide if tocopherol is actually depleted in the fetus and newborn infant by measuring liver tocopherol level. First, a reliable assay method was established as follows. The colorimetric values obtained by Emmerie-Engel's principle from liver extracts which were eluted through a floridin column were corrected by using the ratios of the tocopherol band area to the total scanning values of TLC analysis by densitometry carried out simultaneously. The recovery of tocopherol added to the liver homogenate was always greater than 90%, as measured in this procedure. Thus, tocopherol levels were determined in the human fetal, infant and adult liver with this method. The levels were very low in the fetal liver even though they gradually increased throughout fetal life. After birth, a slight elevation in tocopherol levels was observed during infancy when compared with those in fetal life, but they were still one-third or less of the adult level.

Time course of vitamin E repletion in the premature infant

“…Newborn infants have low circulating concentrations of vitamin E (Dju et al 1958;Mino et al 1977). It has been proposed that this is the result of placental impermeability (Wright et al 1951;Dju & Mason, 1952;Cruz et al 1983), and a transient lipoprotein deficiency at birth (Desai et al 1984).…”

“…Knowledge of membrane vitamin E concentration is, therefore, necessary in any study directed towards elucidating the actions of this vitamin. It is generally agreed that low plasma concentrations of vitamin E in preterm infants are associated with low tissue levels (Dju et al 1958;Mino et al 1977). Recently, however, Mino et al (1985), utilizing erythrocyte (RBC) vitamin E concentrations as an indicator of tissue levels, suggested that the frequency of vitamin E deficiency in premature infants may be lower than previously assumed.…”

Tissue α-tocopherol status during late fetal and early neonatal life of the guinea-pig

“…From the few studies available it appears that the human fetus has low tissue concentrations of vitamin E, and these only increase following initiation of feeding at birth (Dju & Mason, 1952;Dju et a[. 1958;Mino et a!. 1977).…”

“…The newborn infant has low circulating levels of vitamin E (Dju et al 1958;Mino et al 1977; Kelly et al 1990b). In term neonates, plasma vitamin E concentrations increase rapidly following the feeding of colostrum which contains high concentrations of vitamin E (Ostrea et al 1986).…”

“…Surprisingly, fetal and maternal lung a-tocopherol concentrations were similar at all time-points considered, whereas fetal liver a-tocopherol status was always considerably greater than maternal liver a-tocopherol content. These results, if representative of the human fetus, suggest that preterm infants may not have tissue a-tocopherol concentrations as low as previously assumed and that during the perinatal period erythrocyte a-tocopherol content is a more accurate indicator of tissue a-tocopherol concentration than plasma a-tocopherol content.Vitamin E: Fetus: Chronic lung disease: Prematurity : Guinea-pigThe newborn infant has low circulating levels of vitamin E (Dju et al 1958;Mino et al 1977; Kelly et al 1990b). In term neonates, plasma vitamin E concentrations increase rapidly following the feeding of colostrum which contains high concentrations of vitamin E (Ostrea et al 1986).…”