The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.

Animals↗

PubMedDate not supplied

[Effect of thyroxine on the lactate dehydrogenase isoenzyme composition of chicken tissues in ontogeny].

Using disc electrophoresis in polyacrylamide gel, studies have been made on the content of isoenzymes of lactate dehydrogenase in the mitochondria and cytoplasm from the brain, heart and liver after thyroxine administration to embryonal, early postnatal and adult hens. After this administration, the isoenzymic composition becomes more complex, redistribution of separate isozymes being observed in ontogenesis. The level of aerobic form of LDH increases at early stages of ontogenesis, that of anaerobic ones--in adult birds. Basing on their different functional role due to the presence of H- and M-subunits, it may be suggested that thyroxine administration results in a compensatory increase of the oxidative or glycolytic processes at the corresponding stages of ontogenesis, these changes reflecting phylogenetic peculiarities of the formation of the hormonal control of lactate dehydrogenase in tissues of birds.

Animals↗

PubMedDate not supplied

[Progress of nutrition hygiene in the Armenian SSR in the past 50 years].

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Armenia↗

PubMedDate not supplied

[Alpha-ketoglutarate carboxylation in brain and liver subcellular fractions of the hen during ontogeny].

Studies have been made of the role of NADPH and NADH in carboxylation of alpha-ketoglutarate to isocytrate in the cytoplasm and mitochondria of the brain and liver in ontogenesis of hens. In both fractions of the liver, the reaction in the presence of NADPH is more intensive than that in the presence of NADH, being more intense in the cytoplasm than in mitochondria; during embryogenesis, the rate of the reaction increases up to hatching, decreasing at later stages of ontogenesis. No significant changes in the rate of carboxylation were observed during ontogenesis in the presence of NADH. In the brain, the reaction rate in the presence of NADH is higher than that in the liver, being lower in the presence of NADPH. In contrast to that in the liver, NADPH-dependent reaction in the brain is more intensive in mitochondrial fraction. The rate of both reactions, after the initial increase in embryogenesis, decreases at early postnatal stages, except NAD-dependent reaction which is sharply increased in brain cytoplasm of adult hens.

Animals↗

PubMedDate not supplied

[Intracellular distribution of NADP-dependent isocitrate dehydrogenase activity in the tissues of chickens in ontogeny].

The distribution of activity of NAD . P-dependent isocitrate dehydrogenase in the chick liver and brain cytoplasm and mitochondria was studied during ontogenesis. A marked increase of its activity was found in both liver fractions during embryogenesis, with the predominance in mitochondria; the major part of its activity during postembryonic development is localized in the cytoplasm. In the brain tissues where this enzyme is less active in both the factions its activity increased to a greater extent in the mitochondria and exceeded markedly that in the cytoplasm.

Aging↗