Effect of vitamin A on the antioxidant system of the chick during early postnatal development.

1. The effect of increasing vitamin A doses on the concentrations of vitamins A, E, ascorbic acid and carotenoids in the liver and blood plasma of the neonatal chick were investigated. 2. In the 1st experiment 75 d-old chickens were divided into 3 equal groups and in the 2nd experiment 100 d-old chickens were divided into 5 groups. Retinyl acetate in corn oil (1.72; 4.30; 8.60 or 17.2 mg) was intubated directly into the crop daily during the first 5 d after hatch. 3. The intubation of vitamin A increased its accumulation in the liver, with a plateau at about 6,000 microg/g, and was associated with inhibition of vitamin E and carotenoid utilisation from the liver during postnatal development. 4. Moderate amounts of vitamin A intubation increased ascorbic acid concentration in the liver, kidney, brain and plasma. A further increase in vitamin A intubation had an adverse effect on ascorbic acid concentrations in the plasma and brain. 5. The 2 highest inputs of vitamin A decreased glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities in the chicken liver and brain. 6. It is concluded that the effect of vitamin A on development of the antioxidant system in the neonatal chick is dose-dependent and an excess of vitamin A can compromise the antioxidant defence system.

Effect of supplementing the hen's diet with vitamin A on the accumulation of vitamins A and E, ascorbic acid and carotenoids in the egg yolk and in the embryonic liver.

1. The effect of a range of supplementations of vitamin A to the laying hen on the concentration of vitamins A, E, ascorbic acid and carotenoids in the maternal liver, the egg yolk and the embryonic liver were investigated. 2. Four groups of 25 Rhode Island Red hens were fed on standard layer-breeder diets with concentrations of supplemented vitamin A ranging from 0 to 120 micrograms/g retinol equivalents from 28 weeks of age. After 3 months, the concentration of vitamin A in the maternal liver was found to be greatly enhanced in proportion to the increasing rates of supplementation with the vitamin. However, the concentration of vitamin E in the maternal liver was markedly reduced by high dietary contents of vitamin A. 3. The concentration of vitamin A in the yolk of the hens' eggs was markedly increased by the dietary supplementation. However, the concentration of both vitamin E and carotenoids in the yolks were significantly reduced by high dietary contents of vitamin A. 4. The concentration of vitamin A in the liver of the embryo and the day old chick was greatly increased by the high concentrations of maternal vitamin A provision. However, the concentration of vitamin E, carotenoids and ascorbic acid in the embryonic/neonatal liver were significantly reduced by high contents of vitamin A in the maternal diet. 5. The susceptibility of the embryonic/neonatal liver to lipid peroxidation was significantly increased as a result of high provisions of maternal vitamin A. 6. It is concluded that excessive provision of vitamin A to the laying hen results in an adverse effect on vitamin E, carotenoids and ascorbic acid in the embryonic/neonatal liver and can compromise the antioxidant status of the progeny.

[Vitamins E and C as components of the antioxidant system in avian and mammalian embryos]. / Vitaminy E i C kak komponenty antioksidantnoi sistemy émbrionov ptits i mlekopitatiushchikh.

New information about functional properties and peculiarities of alpha-tocopherol and ascorbic acid interaction in birds embryos organism with providing of adequate antioxidant status in embryogenesis and early ontogeny are given. Some characteristics of these natural antioxidants action in different embryonal tissues on the inhibition of lipids peroxidation processes depending on their level in the organism are shown.

[Characteristics of the composition of fluorescent lipopigments of the liver and brain in rats of various ages]. / Osobennosti sostava fliuorestsiruiushchikh lipopigmentov pecheni i mozga krys raznogo vozrasta.

Spectral characteristics of the lipid liver and brain extracts were studied in experiments on rats of different age (1, 3, 12, 24 months). The aim of the experiments was to study age peculiarities of the lipopigments composition by means of thin-layer and liquid chromatography. Different fractions of lipids which differ in spectral absorption and fluorescence were extracted. Proceeding from the results obtained certain conclusions may be derived: the processes of structural recombination of the whole lipid constituents are accompanied by the age accumulation of lipofuscin; the process of accumulation of lipofuscin is not monotonous and has pronounced age peculiarities; the formation of the lipid-pigment complex is tissue-specific.

[Practical aspects of using silufol sheets to analyze fat-soluble vitamins]. / Prakticheskie aspekty ispol'zovaniia plastinok silufol dlia analiza zhirorastvorimykh vitaminov.

The authors studied the mobility of the fat-soluble vitamins, A, D, K1 and beta-carotene in organic solvents and their mixtures on silufol plates, the influence of the chromatography conditions and the chamber saturation with the solvent vapors on the Rf values of fat-soluble vitamins, as well as the rate of beta-carotene tocopherol (vitamin E) and phylloquinone (vitamin K1) destruction under the effect of the day and ultra-violet light. The data obtained are presented. Phylloquinone and carotene proved to be most destroyed, while tocopherol was more resistant under the same conditions. Silufol plates can be used for the control of the production of vitamins, their analysis in varying biological objects, as well as in biochemistry, medicine and pharmaceutics.