[Correlation of tissue respiration and some mitochondria stereometric characteristics of the lung tissue in different modifications of hypoxic hypoxia].

In experiments on the adult white laboratory rats the correlation of tissue respiration and some morpho- and stereometric characteristics of mitochondria in lung tissue under breathing by air and gas mixture with 7% O2 in N2 was investigated. The following agents were used as modulators: indomethacin, a blockator of cyclooxygenase way of arachidonic acid metabolism; quercetin and linoleil of hydroxamic acid, blockators of lipooxygenase way ofarachidonic acid metabolism; taurine, an antihypoxant and energy source under hypoxic conditions; lipin-antihypoxant with significant membrane protective effect. It was shown, that the respiration intensity of tissue homogenate, not only of its mitochondrial fraction, closely connected with structural organization of mitochondria. It was demonstrated that changes of O2 concentration in gas mixture lead to the alteration of interrelation between O2 consumption and stereometric characteristics of mitochondria: in normoxia the intimate correlation was established with number of mitochondria and its total surface; in hypoxia such correlation was established with mitochondria diameter and number of structurally damage organelles. Pharmacological modulation factors play in this process not so significant role.

[Effect of intermittent hypoxic hypoxia on energy supply of rat skeletal muscle during adaptation to physical load].

The experiment, on Wistar male rats was carried out to investigate influence of endurance training (swimming with load 7.0 +/- 1.3% body weight, 30 min a day, during 4 weeks) and additional intermittent hypoxic training (12% O2 in N2 - 15 min, 21% O2 - 15 min, 5 sessions a day, during the first 2 weeks) on the following parameters: ADF-stimulated mitochondrial respiration, lactate/pyruvate ratio, succinate dehydrogenase activity, and lipid peroxidation in skeletal muscle. The next oxidation substrates were used: 1 mmol/l succinate and 1 mmol/l alpha-ketoglutarate as well as the next inhibitor succinate dehydrogenase 2 mmol/l malonate. It was shown that physical work combined with intermittent hypoxic training led to the increase of mitochondrial respiration effectiveness in muscle energy supply under alpha-ketoglutarate oxidation in comparison with succinate oxidation as well as to the decrease of succinate dehydrogenase activity and lipid peroxidation. The study suggested that these changes may correct mitochondrial dysfunction under intensive muscular work.

[Effect of intermittent hypoxic training on indices of adaptation to hypoxia in rats during physical exertion]. / Vplyv interval'noho hipoksychnoho trenuvannia na pokaznyky adaptatsiï shchuriv do hipoksiï navantazhennia.

The aim of this study was to investigate physical endurance, maximal oxygen uptake, oxygen partial pressure, and pH in blood and skeletal muscle as well as the muscle metabolic parameters (lactate and pyruvate concentration, lactate/pyruvate and NAD/NADH ratios, succinate dehydrogenase activity, ADP-stimulated mitochondrial respiration) under various regimen of combination of endurance training with intermittent hypoxic training (IHT) in adult Wistar rats. It was shown that physical endurance, maximal oxygen uptake, and muscle PO2 (PmO2) were maximally increased in those animals who simultaneously underwent endurance training and IHT. The same animals demonstrated the minimal decrease in PmO2, blood and muscle pH under testing intensive physical workload. The latter led to the lesser shifts in metabolic parameters in the muscle of rats adapted both to IHT and endurance training than in rats adapted to endurance training only. The combined effects of IHT and adaptation to load hypoxia resulted in an increase of the role of NADH - oxidation pathway in the mitochondrial energy production.

[Effect of N-oxidized pyridine derivatives on lipid peroxidation in the livers of rats]. / Vplyv N-okysnenykh pokhidnykh pirydynu na kysnezalezhni protsesi v tkanyni pechinky shchuriv.

Effects of N-oxide 2,6-dimetilpyridine (ivin) on the intensity of lipid peroxidation (in vivo and in vitro), microsomal hydroxylation and secretion of the bile (in vivo) were investigated. It has been shown that the preparation did not act significantly on the rate of lipid peroxidation in the liver homogenates both in vivo (5 mg/100 g, 4 weeks) and in vitro (10(-6)-10(-2) mol, incubation). Ivin did not change the activity of the microsomal hydroxylation (hexenal), but stimulated the excretion of biliary organic and inorganic components. The role of NO as a transmitter for effects of N-oxide 2,6-dimetilpyridine and the possibility of its influence on the processes under exploration via the modification of the structure of a biomembrane have being discussed to be one of the basic mechanisms.

[Disturbances in biliary secretion during tissue hypoxia and attempts at their corrections]. / Porushennia protsesiv zhovchovydilennia pry tkanynnii hipoksiï ta sproby ïkh korektsiï.

In acute experiments on rats in vivo the stimulating effects of hydrophilic cholic acids (CA and UDCA) on the bilification and their inhibiting by rotenone have been shown. The secretion of CA and UDCA under rotenone have been determined to be activated. The mechanisms of the influence of the cholic acids on the secretory function of the hepatocytes have being discussed. It has been concluded that NADH-dehydrogenase link in the respiratory chain is not involved in the activating effects by CA and UDCA.

[A mathematical model of the physiological estrous cycle in outbred rats]. / Matematicheskaia model' fiziologicheskogo éstral'nogo tsikla besporodnykh krys.

The mathematical model of the physiological estrous cycle of the laboratory rat was developed. The data on physiological concentration of the hormones, participating in the estrous cycle regulation and admittances on the growth and selection of the ovarian follicles made the base of the model. The developed system of differentiated equations allowed to reproduce quiet precisely the duration of the estrous cycle phases, to follow up the behaviour of the apparent cohort of the growing ovarian follicles during several cycles. The model is a base for the studying of the effect of the different factors on the estrous cycle.

[Effect of liposomes on tissue respiration in animals with acute hypoxic hypoxia]. / Vplyv liposom na stan tkanynnoho dykhannia u tvaryn pry hostrii hipoksychnii hipoksii.

Introduction of liposomas has been studied in experiments on Wistar rats for its effect on oxygen demand by tissues of the brain great hemispheres, lungs, liver and femoral muscle under acute hypoxic hypoxia due to inhalation by an animal of gas mixtures containing of 6.7-7.1% of O2. It is shown that after introduction of phospholipid liposomes as a lipin preparation against a background of acute and grave forms of hypoxic hypoxia the oxygen demand of tissues remains practically at the level of control values. This proves absence of the tissue oxygen debt that usually develops at hypoxic states. It is concluded that the organism tissues in the presence of liposomas do not practically suffer from the oxygen deficiency and introduction of lipin may be effective to prevent from development of the secondary tissue hypoxia.

[Activation mechanisms of lipid peroxidation in rat's tissue in various types of hypoxia]. / Osoblyvosti mekhanizmiv intensyfikatsii perekysnogo okyslennia lipidiv u tkanynakh shchuriv pry gipoksii riznogo typu.

The mechanisms of lipid peroxidation (LP) intensification in the rat myocardium, brain and liver were studied under hypoxic hypoxia and hemic hypoxia. The level of intensification depends on the type of hypoxia and is characterized by tissue specificity. It is shown that LP is activated by hypoxia. This activation is more pronounced under hemic hypoxia associated with more marked catecholamine accumulation, deficiency of the antioxidant glutathione system, decrease of the cytochrome c-oxidase activity. The level of lipid peroxides was higher in the rat liver under both types of hypoxia.

[Some mechanisms of antihypoxic action of taurine]. / Deiaki mekhanizmy antygipoksychnoi dii taurinu.

It is shown that preliminary taurine treatment prevents the disturbances of energy metabolism in the brain, heart and liver tissues of Wistar rats with acute hypoxic hypoxia. Administration of taurine restored to normal the parameters of adenine pool: the concentration of ATP increased within the cytoplasm, while that of ADP and AMP diminished; mitochondrial respiration proceeded more rapidly; the concentrations of pyruvate and malate decreased; isocitrate dehydrogenase activity, P/O and NAD/NADH ratios increased. Taurine treatment resulted in a decreased level of lipid peroxides in the rat tissues with hypoxia. The role of intracellular calcium content and biomembranes structure changes as the mechanisms of taurine action on energy metabolism and lipid peroxidation is discussed.

[The characteristics of the effect of inert gases on tissue respiration in vivo]. / Osoblyvosti vplyvu inertnykh gaziv na tkanynne dykhannia in vivo.

Helium-oxygen and argon-oxygen gaseous mixtures have been studied for their effect on tissue respiration. It is shown that 1-hour exposition of animals induces an increase in the oxygen consumption of the liver tissue (more essential in the presence of helium in the gaseous mixture).

[New paths in the pathogenetic correction of hemic hypoxia]. / Novi shliakhy patohenetychnoï korektsiï hemichnoï hipoksiï.

It is stated that prophylactic administration of ional (dibunol) and taurine to rats exerts an antihypoxic effect in case of acute hemic hypoxia. It is expressed in a decrease of methemoglobin level in blood, increase of pO2, in the skeletal muscles, normalization of the structure of hematoparenchymatous barriers, prevention or decrease in a fall of the rate of oxygen consumption by tissues.

[The effect of inert gases on the intensity of lipid peroxidation in the rat liver]. / Vliianie inertnykh gazov na intensivnost' perekisnogo okisleniia lipidov v pecheni krys.

The presence of helium and argon in gas mixtures increases the peroxidation rate of lipids in homogenates and has no influence on this index in the mitochondrial and microsomal fractions of the rat liver. An assumption is advanced that the realization of effects of the inactive gases in question is realized via the plasma membranes of cells.

[Effect of replacement of air nitrogen by inert gases on oxygen consumption by the liver tissues in albino rats on various fatty diets]. / Vliianie zameny azota vozdukha inertnymi gazami na potreblenie kisloroda tka'niu pecheni belykh krys, nakhodivshikhsia na raznykh zhirovykh dietakh.

The effects of helium and argon, inert gases, on oxygen consumption have been studied on liver tissue of white rats who were delivered different fatty products plus to basic food). It is shown that the effects of helium and argon on the tissue respiration depend on the nature of fatty products. The role of membrane structure in realization of the influence of inert gases on tissue respiration is under discussion.

[Effect of helium and argon on the oxygen uptake by lymphocytes]. / Vliianie geliia i argona na potreblenie kisloroda limfotsitami.

The effect of inert helium and argon gases on the tissue respiration has been studied on lymphocyte suspensions of white rats. It is shown that normoxic helium-oxygen mixture induces almost a two-fold increase of the O2 uptake by lymphocytes as compared with the control (air). No deviations in the value of the studied parameter are revealed in case of replacement of nitrogen from air by argon. Significance of the membrane structure in realization of effects of inert gases is under discussion.

[Effect of starvation on respiratory reactivity in inbred rats]. / Vliianie golodaniia na reaktivnost' dykhaniia u inbrednykh krys.

The 5-day starvation, with water ad libitum, decreased the reactivity of the respiration system to acute hypoxic hypoxia (11% O2) in spontaneously hypertensive (SH) rats and had no such effect in Krushinskii-Molodkina (KM) rats. The difference in the responses of KM and SH rats to starvation and the action of hypoxic gas mixture shows that the respiratory system reactivity has an obvious genetic component.