[Role of iodothyronine-deiodinase in thyroid hormone mechanisms in animal and human cells]. / Rol' iodotyronin-deiodynaz u mekhanizmakh diï tireoïdnykh hormoniv u klitynakh tvaryn ta liudyny.

New data concerning molecular structure, localization and functions of iodothyronine deiodinases in animal and human organisms are reviewed in the article. Mechanisms of 5- and 5'-deiodination of thyroid hormones by intracellular iodothyronine deiodinases are considered, the role of these enzymes in the processes of biologically active iodothyronine formation and thyroid hormone inactivation are shown. The data which suggest functioning iodothyronine-5'-deiodinases in the cells of haemopoietic and lymphopoietic systems, and connection between the rate of enzyme expression and cell differentiation level are adduced. Participation of thyroid hormones and other factors in the regulation of expression and functional activities of iodothyronine-5'-deiodinases in the cells is discussed. The important role of iodothyronine deiodinases in mechanisms of optimization of intracellular thyroid status in altered physiological state of organism, during ontogenesis and in pathological conditions is considered.

[The effect of thyroxine on the enzymatic activity of the energy metabolism and antioxidant system in the neutrophilic granulocytes of piglets]. / Vplyv tyroksynu na aktyvnist' fermentiv enerhetychnoho obminu ta antyoksydantnoï systemy v neitrofil'nykh hranulotsytakh porosiat.

The influence of thyroxine on activity of enzymes of energy metabolism (hexokinase, phosphofructokinase, pyruvate kinase, laktate dehydrogenase, glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase, cytochrome-c oxidase) and antioxidative system (glutathione peroxidase, glutathione reductase, superoxide dismutase) of neonatal piglet neutrophils was investigated. It has been found, that after durable injections of hormone (4 mg/kg body weight) the increase of glycolytic enzymes activities as well as aerobic energy pathway catalyzers took place. Simultaneously the augmentation of superoxide dismutase reaction occurred after the thyroxine treatment. Such effect might represent an important link in compensatory mechanism, which prevents the destructive action of reactive oxygen species.

[The influence of cortisol on several links of metabolism in myeloid cells and leukocytes]. / Vplyv hidrokortyzonu na deiaki lanky metabolizmu v miieloïdnykh klitynakh i leikotsytakh.

The influence of cortisol on the activity of enzymes that catalyze several stages of energy metabolism, proteolysis and antioxidant system in the bone marrow myeloid cells, neutrophils and lymphocytes of 7-10-day aged piglets was investigated. It was established that durable hormone administration (40 mg per kg body weight every 12 hours during 3 days) caused the decrease in the initial stages of glycolysis and pentose phosphate way intensities, as well as inhibition of cytochrome-c oxidase and antioxidant enzymes activities in the cells of mentioned populations. Such effects of cortisol on the intracellular metabolism may represent the important link in the mechanisms of glucocorticoid inhibition of myeloid cells and circulating leucocytes functional activities.

[Characteristics of some stages of energy metabolism and antioxidant system in bone marrow myeloid cells and leukocytes from piglets]. / Kharakterystyka okremykh lanok enerhetychnoho metabolizmu ta antyoksydantnoï systemy v miieloïdnykh klitynakh kistkovoho mozku i leikotsytakh porosiat.

The age changes of enzymes of activity catalyzing several links of energy metabolism (hexokinase, phosphofructokinase, pyruvate kinase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase, cytochrome c-oxidase) and antioxidant system (superoxide dismutase and glutathione reductase) in bone marrow myeloid cells and blood leukocytes of pig in the 10-day period after birth were investigated. The bone marrow cells and leukocytes of the new born piglets were characterized by low intensity of oxidative steps of energy metabolism as well as by low activity of antioxidant enzymes. In the period of neonatal adaptation reorganization of energy metabolism, particularly, intensification of oxidative processes in the investigated cells occurred. It included the pentose phosphate way and cytochrome c-oxidase activation. During the neonatal period of development the functional activity of antioxidant enzymes in the investigated cells of piglets increased.

[The age-related changes in the antioxidant system enzymes of the erythroid cells of swine at the early stages of postnatal development]. / Vikovi zminy aktyvnosti fermentiv antyoksydantnoï systemy v erytroïdnykh klitynakh svynei na rannikh stadiiakh postnatal'noho rozvytku.

The age changes of energy metabolism and antioxidative system enzymes activity in "young", "mature" and "old" erythroid cells of 0-, 1-, 3-, 5-, 10-days old piglets were studied. The essential increase of superoxide dismutase and glutathione peroxidase activities in pig erythrocytes during three days of postnatal life was established. The rise of glucose-6-phosphate dehydrogenase and NADPH-dependent glutathione reductase activities was observed in piglets erythrocytes in the period from 5 to 10 days after birth. The discovered changes of enzymatic activity were particularly characteristic of the "young" cells. It is supposed that this mechanism is essential in erythrocyte membrane structures stabilization in the period of early postnatal adaptation of animals.

[Biochemical role of selenium]. / Biokhimichna rol' selenu.

The molecular mechanisms of selenium regulation of biochemical functions in animal and human tissues are presented in review. It is shown, that in spite of high toxicity selenium is an essential nutrient for people and animals. Taking into account deficit of this microelement in fodder it is necessary to use the selenium compounds in rations of domestic animals and poultry. The study of properties and characteristics of selenoproteins is important in discovering selenium role in regulation of cellular growth processes, the protective effect of this element in prevention of toxic action of heavy metals, xenobiotics and bacterial toxins on organism and anticarcinogenic effect of selenium.

[Activity of enzymes of glycolysis in pig erythrocytes in the neonatal period]. / Aktyvnist' deiakykh fermentiv hlikolizu erytrotsytiv porosiat u neonatal'nomu periodi.

The age changes of 2,3-DPG concentration, 2,3-diphosphoglycerate mutase, hexokinase and pyruvate kinase activities in pigs erythroid cells during the first 10 days after birth have been investigated for study of the mechanism of blood oxygen-transport function regulation at the early stages of postnatal adaptation. It was established, that there are age peculiarities in young, mature and old erythrocytes metabolism in piglets during the transition to postnatal development. It was shown that the rise of 2,3-DPG, the allosteric effector of hemoglobin oxygen affinity level, is due to the increased activities of 2,3-diphosphoglycerate mutase and hexokinase after birth, that is particularly characteristic of the young pigs erythrocytes.

[The effect of starvation during an early postnatal period on carbohydrate metabolism in the swine brain]. / Vplyv goloduvannia u rannii postnatal'nyi period na obmin vugkevodiv u golovnomu mozku svynei.

Metabolism of carbohydrates in the brain of 110-day-feti, newborns (before taking the colostrum), 1-day-old and 5-day-old piglets, grown under sows or starved for 24 hours has been studied. Examination of brain slices with the use of 1-14C glucose and 6-14C glucose and determination of the glycolysis-limiting enzymes activity have shown that glycolysis is the main pathway of glucose utilization in the central nervous system of pigs during the transition from prenatal to postnatal development. The major portion of NADPH in the brain of new born piglets is supplied by dehydrogenases of the pentose-phosphate pathway. The increased activities of NADP-dependent malate and citrate dehydrogenases are found in the cytoplasm of astrocytes during the neonatal period. The decreased intensity of glycolysis and pentose-phosphate pathway in the brain of 1-day-old piglets is associated with the increased rate of malate and isocitrate oxidation. Starvation for 24 hours causes changes in the carbohydrate metabolism rates in the brain of piglets. The pentose-phosphate pathway rate increases by 70-80 per cent in the brain structures of piglets of the both groups. Besides, the iso-CDG activity also rises in the brain of 5-day-old animals. The high level of oxidation-reduction processes in the brain of older piglets at active glycolysis is supposed to be one of the peculiarities of energy metabolism in the central nervous system of animals which are resistant to starvation.