Rats on a normal diet were administered physiological doses of [3H]retinyl acetate or [3H]retinol orally for 5 days to label endogenous retinoid pools. The kidney retinoids were extracted and separated by DEAE-Sephadex into neutral and acidic fractions. All-trans-retinoic acid and 5,6-epoxyretinoic acid were isolated and unequivocally identified by chromatographic analysis, chemical derivatizat...

Vitamin A can have different effects on developing and regenerating limbs depending on the mode of administration. Previous work has demonstrated the differential effect of retinol palmitate on limb development and regeneration in Xenopus laevis. The purpose of the present investigation was to determine the effects of vitamin A on limb development and regeneration in Xenopus when administered b...

Vitamin A can have different effects on developing and regenerating limbs depending on the mode of administration. Previous work has demonstrated the differential effect of retinol palmitate on limb development and regeneration in Xenopus laevis. The purpose of the present investigation was to determine the effects of vitamin A on limb development and regeneration in Xenopus when administered b...

We report successful vitamin A supplementation by inhalation of retinyl palmitate in a placebo-controlled pilot study in twenty-five preschool children (2-5 years of age) in the rural district of Gondar, Ethiopia. Preschool children (n 161) were randomly selected from 220 households. Out of this cohort, twenty-five children were randomly assigned to each of two treatment groups: one receiving r...

In this work, we evaluate the lung retinoids content to study the possible difference between male and female mice during prenatal development and to comprehend if the vitamin A metabolism is similar in both genders. The study occurred between developmental days E15 and E19, and the retinol and retinyl palmitate lung contents were determined by HPLC analysis. We established two main groups: the...

We describe the use of HPLC with muitiwavelength detection to measure retinol, a-tocopherol, Iutein/zeaxanthin, f3-cryptoxanthin, lycopene, a-carotene, trans-p-carotene, /3-carotene, and the linoleate, oleate, palmitate, and stearate esters of retinol in a single 200L serum sample. The method is sensitive enough to detect individual retinyl esters in fasting serum from a nonhyperlipidemic popul...

BACKGROUND Retinol is a lipid-soluble essential nutrient that is stored as retinyl esters in lipid droplets of hepatic stellate cells. Patatin-like phospholipase domain-containing 3 (PNPLA3), through its retinyl-palmitate lipase activity, releases retinol from lipid droplets in hepatic stellate cells in vitro and ex vivo. We have shown that the genetic variant I148M (rs738409) reduces the PNPLA...

The mechanism of the intestinal esterification of retinol has been obscure. Recently, an acyl-Coenzyme A (CoA):retinol acyltransferase (ARAT) was found in rat intestinal microsomes, and experiments were therefore conducted to determine whether a corresponding enzyme exists in human small intestine. When microsomes were incubated with [3H]retinol and palmitoyl-CoA, or retinol and [1-14C]palmitoy...

Vitamin A and other retinoids are known to have an effect on biological membranes. We measured the effects of retinol, retinoic acid and retinyl palmitate on in vitro osmotic fragility, spontaneous hemolysis and membrane microviscosity of human red blood cells (RBC)., Incorporation of retinol into the erythrocyte membrane was also studied. The effect of large doses of retinol on adenosine dinuc...

PURPOSE Interphotoreceptor retinoid-binding protein(IRBP) is a four-repeat protein found in the interphotoreceptor space. Each repeat can bind retinoids and fatty acids. The purpose of this study was to examine the effects of the single amino acid substitution, G239T, versus the wild type sequence of human IRBP Repeat 1, on ligand binding at equilibrium, ligand off rates, and protection of reti...