[Free radical processes in the rat blood during hyperbaric oxygenation and in the posthyperoxic period]. / Svobodno-radikal'nye protsessy v krovi krys pri giperbarooksigenatsii i v postgiperoksicheskii period.

Effects of prolonged action of low-pressure oxygen (0.3 MPa, 5h) on the free-radical oxidation (FRO) intensity were investigated just after oxygen exposure and 1, 3, 7, days after that. The FRO increase against the background of the anti-radical systems depression was shown by means of blood plasma chemiluminescent analysis. Under these conditions SOD activity and the content of diene conjugates and Schiff's bases increase in erythrocyte membranes. The displacement of equilibrium between pro- and antioxidants and antioxidants contents towards the latter took place in blood plasma on the 1st day after oxygen exposure. The erythrocyte SOD activity was raised while catalase activity was diminished. The last one was accompanied with the decrease in erythrocyte membrane diene conjugates amount. The secondary blood plasma and erythrocyte membrane FRO elevation was observed on the 3rd day after the exposure and, it was held on the 7th day after hyperoxia. The FRO increase in post-hyperoxia period was established.

[Dynamics of luminol-dependent chemiluminescence in rat whole blood at different oxygen concentrations]. / Dinamika liuminolzavisimoi khemiliuminestsentsii tsel'noi krovi krys pri razlichnykh kislorodnykh rezhimakh.

Chemiluminescence analysis was used to examine the yeast cell-activation of rat whole blood neutrophilic leukocytes in rats after their pre-exposure to 3-hour hypoxia (9,000 m above sea level) and two-hour hyperoxia (0.3 MPa), as well as their resultant effects. The hypoxia was found to cause a significant (42%) reduction in the length of the latent period, suggesting that it activates the phagocytic activity of neutrophilic leukocytes. At the same time hyperoxia leads to a delayed response of competent cells to yeast cell stimulation. On subsequent exposure to hypoxia and hyperoxia, drastic inhibition of drastic cellular activation occurred, which manifested itself by a 62% increase in the length of the latent period and by a 38% rise in the appearance time of luminescence peak. Thus, the findings suggest that it is essential to bear in mind the fact that phagocytosis can decrease if oxygen is overdosed during hyperbaric oxygenation and in hypoxic states.

[Biochemical composition of a surfactant and its free radical processes in hyperbaric oxygenation and in the post-hyperoxic period]. / Biokhimicheskii sostav surfaktanta i svobodnoradikal'nye protsessy v nem pri giperbarooksigenatsii i v postgiperoksicheskii period.

Monitoring was made to examine the lungs. With this mode of hyperbaric oxygenation (0.3 MPa for 5 hours), rats developed mild oxygen intoxication which alleviated on day 3 and ceased on day 7 after its exposure. At the same time there were profound changes in the surfactant levels of protein, phospholipids, and cholesterol, which became normal on day 7 of postexposure. Chemiluminescence analysis and measurements of lipid peroxidation (PLO) products indicated that PLO rates in the surfactant decreased during hyperbaric oxygenation and remained at low levels within 24 hours of postexposure, whose cause might be activated by the antioxidative systems, as considered by the authors. However, on day 3 PLO enhances and on day 7 a new level of free-radical processes established, which was characterized by higher concentrations of free radicals and enhanced the activity of the antiradical systems.

[Lipid peroxidation intensity during periodic hypoxia and the protective effect of pyrazidole]. / Intensivnost' perekisnogo okisleniia lipidov pri periodicheskoi gipoksii i zashchitnom deistvii pirazidola.

The effect of 3- and 10-day intermittent hypoxia corresponding to the altitude of 5000 m above the sea level (4 hrs daily) has been studied. The increase in the content of brain and lung diene conjugates and Schiff bases indicative of the increase in the rate of lipid peroxidation has been shown to be associated with hypoxia. The activity of superoxide dismutase (SOD) increases in the brain under 3-day hypoxia and decreases considerably in the brain and the lung under 10-day hypoxia in comparison with 3-day hypoxia. Administration of the monoamine oxidase inhibitor pyrazidol normalizes the content of diene conjugates in the lung and that of Schiff bases in the brain under 3-day hypoxia as well as prevents completely the increase in the rate of lipid peroxidation under 10-day hypoxia. The activity of SOD increases in the brain and the lung of pyrazidol-protected animals under 3-day hypoxia. Pyrazidol administration under 10-day hypoxia prevents the SOD activity decrease in the brain. The protective effect of pyrazidol under intermittent hypoxia is discussed.

[Emoxipin correction of disorders of lipid peroxidation as affected by a slight excess of oxygen pressure]. / Korrektsiia émoksipinom narushenii perekisnogo okisleniia lipidov pri deistvii nizkogo izbytochnogo davleniia kisloroda.

The role of the emoxipin (Em.) (2-ethyl-6-methyl-3-oxipyridine) in the correction of the free radical oxidation and allied processes in lung tissues and blood plasma under high-pressure oxygen-prolonged action has been investigated. The studied oxygen exposure (0.3 MPa, 5h) causes the lung stage of oxygen intoxication. It is confirmed by exterior morphological assessment of the lung. The lipid peroxidation increase in lung tissue and blood plasma as well as erythrocyte membranes destabilization result from oxygen exposure. Lipid peroxidation intensity was estimated by determining of content of lipid peroxidation molecular products such as diene conjugates and Shiffs' bases. Erythrocyte membranes stability was evaluated with hemoglobin yield, total iron level and total peroxidase activity in blood plasma. Emoxipin was injected intraperitoneally in a dose 150 mg per 1 kg rats' weight just before the oxygen exposure. Emoxipin is found to improve physiological state of animals and to increase their survival; it normalizes morphology of the lungs and their state; stabilizes erythrocyte membranes injured under oxygen exposure; decreases intensity of lipid peroxidation processes in the lungs and in blood plasma which was previously increased under hyperoxia.

[Free-radical processes in the lung tissue of rats under hyperbaric oxygenation and in the posthyperoxic period]. / Svobodnoradikal'nye protsessy v tkani legkikh krys pri giperbaricheskoi oksigenatsii i v postgiperoksicheskii period.

An increased antioxidation enzyme activity and a low level of the peroxidation products were revealed in exposure to low oxygen pressure and 1 to 7 days after it in rats. The data obtained suggest presence of a powerful antioxidant system in the rat lung.

[The effect of hypoxia on membrane status and lipid peroxidation in rat lungs and blood]. / Vliianie gipoksii na sostoianie membran i perekisnoe okislenie lipidov v legkikh i krovi krys.

A state of lysosomal membranes and lipid peroxidation were studied in rat lungs under hypoxic conditions at the height 9,000 m, 3 hrs. Under these condition content of protein in lungs was decreased by 12% but free activity of lysosomal peptide hydrolases was simultaneously increased by 66%, indicating the lysosomal membranes labilization. At the same time, content of lipid peroxidation products--diene conjugates and Schiff bases, was decreased in lung synchronously with activation of the antioxidant enzymes catalase and superoxide anion dismutase. The lung tissue appears to have more powerful mechanisms of adaptation to deficiency of oxygen as compared with other tissues. Under hypoxic conditions content of protein in blood serum was similar to that of control values, while activity of lysosomal enzymes was increased by 26%, which occurred apparently due to an increase in the rate of lipid peroxidation. Actually, amount of lipid peroxidation products was increased in erythrocyte membranes but activity of SOD was not altered and the activity of catalase--tended to decrease. Thus, one of possible reasons of lipid peroxidation product accumulation in blood may be a lowered activity of the antioxidative enzymes.

[Micro-determination of the intensity of luminol-dependent chemiluminescence of plasma]. / Mikroopredelenie intensivnosti liuminolzavisimoi khemiliuminestsentsii plazmy.

The authors attempted to modify the macro-method for assessment of the intensity of luminol-dependent chemiluminescence by using small volumes of capillary blood, diluted 100-fold. They have demonstrated the compatibility of two methods for blood collection, from the vein and from the finger, on the basis of the rapid test of oxygen intoxication severity and individual sensitivity of the body to hyperoxia in vitro. Use of microvolumes of the sample for analysis will facilitate the clinical application of the test for the selection of the optimal HBO schemes.

[Status of cell membrane enzymes in hypoxia and the protective effect of pyrazidole]. / Sostoianie membrannykh fermentov kletki pri gipoksii i zashchitnyi éffekt pirazidola.

The influence of hypobaric hypoxia simulating the altitude of 9000 m above the sea level during 3 hours on the stability of erythrocyte, lysosomal, and mitochondrial membranes, has been studied. The increase in extra erythrocyte hemoglobin and free iron concentrations and the total peroxidase activity in blood plasma testify to increased permeability of the erythrocyte membrane. An increase in the free activity of acid peptide hydrolases in the soluble fraction and their activity decrease in the lysosomal membrane. The mitochondrial monoamine oxidase activity in the soluble fraction of the brain is suggestive of structural damages to the mitochondrial membrane. Preliminary administration of pyrasidol prior to hypoxia has a stabilizing effect on all types of membrane structures.

[Effects of arginine on properties of the erythrocyte membrane in hypoxia]. / Vliianie arginina na svoistva éritrotsitarnykh membran v usloviiakh gipoksii.

The antioxidant effect of arginine evident from stabilization of membrane structure and properties and activation of oxygen-toxicity-protecting enzymes was demonstrated in hypoxia. The intraperitoneal injection of L-arginine-HCl in a dose of 120 mg per 100 g body mass prevented the increase of microviscosity, membrane permeability and lipid peroxidation products level in hypoxia. At the same time the activity of the antioxidant enzymes--superoxide dismutase and catalase--was increased in red blood cells by 64 and 46%, respectively.

[Effect of arginine and its analogs on the activity of lysosomal and nonlysosomal peptide hydrolases in rat tissues]. / Vliianie arginina i analogov na aktivnost' lizosomal'nykh i nelizosomal'nykh peptid-gidrolaz v tkaniakh krys.

The autolysis intensity and proteolysis activity at pH 4,5, 7,4, 8,5 and lysosomal and nonlysosomal peptide hydrolase activity have been studied in brain and liver tissues of rats. L-arginine has been found to increase the peptide hydrolase activity in neutral and alkaline media in case of autolysis and proteolysis estimation according to the amino nitrogen increase. When the peptide hydrolase activity is estimated according to the increase of folin-positive components its decrease under the action of arginine in neutral and alkaline media has been revealed. Arginine doesn't change the lysosomal peptide hydrolase activity. In both tissues under the influence of arginine the nonlysosomal peptide hydrolase activity defined by amino nitrogen increases, estimated by the folin-positive components--decreases. Arginine shows the specific influence on the nonlysosomal peptide hydrolase activity. The L-arginine analogues (D-arginine, guanidine) and products of the arginase reaction (ornithine and urea) don't exert such an effect on the nonlysosomal proteolysis.

[Biochemical indices of the differentiation of cold stress and adaptation]. / Biokhimicheskie pokazateli differentsirovki kholodovogo stressa i adaptatsii.

Monoamine oxidase, acid peptide-hydrolase activities, intensity of lipid peroxidation in brain and liver tissues, hemoglobin content in blood serum, total peroxidase activity and glucose-6-phosphate dehydrogenase activity were investigated during the cold acclimation within 1-45 days, 4 degrees. Cold stress within 1-3 days destabilized erythrocyte, lysosomal and mitochondrial membranes in the rat tissues studied. At the same time, cold adaptation within 45 days prevented the membrane labilization.

[Effect of arginine on the activity of proteolytic enzymes in the rat brain and liver]. / Vliianie arginina na aktivnost' proteoliticheskikh fermentov v mozgu i pecheni krys.

The influence of arginine on autolysis and proteolysis was studied. Arginine at the concentration of 0.5 and 1.0 microM/ml was added to the incubation mixture. Proteolytic processes were studied in the acid, neutral and alkaline media (pH 4.5; 7.4; 8.5). Autolysis was determined by incubation of the brain and liver homogenates and proteolysis by the use of bovine serum albumin as a substrate. Autolytic and proteolytic activities were calculated as an increase of Folin positive compounds or amino nitrogen in the samples. It was established that the influence in vitro of arginine on the proteolytic processes depended on pH, type of the peptide-hydrolases, to a lesser extent, on the arginine concentration and did not depend on the tissue type. Arginine displayed its regulative action in the brain and liver by the same way. The addition of arginine had an effect on autolysis and proteolysis in the neutral and alkaline media. Determination of autolytic and proteolytic activities by Folin positive compounds has shown that arginine addition into the samples decreased autolysis and proteolysis. At the same time determination of autolysis and proteolysis by amino nitrogen in the presence of arginine has shown that autolytic and proteolytic activities increased.

[Effect of extreme exposure on the intensity of autolysis in the brain and liver of rats]. / Vliianie ékstremal'nykh vozdeistvii na intensivnost' avtoliza v mozge i pecheni krys.

Stress caused by 3-hour cold exposure of the animals (2-4 degrees C) or 7-day starvation is accompanied by the increase of protein autolysis in liver by 21%. At that the intensity of the autolysis in brain leaves unchanged. In spite of the same changes of the autolysis intensity in brain and in liver in cold-exposed and starved animals, the level of pholinpositive compounds in liver and brain of these two groups of animals changes in different ways in comparison with the control one. The level of pholinpositive compounds in liver of cold-exposed aminals lowers by 51%, in liver of starved animals does not change; in brain of cold-exposed animals decreases by 27% and in brain of starved ones increases by 69%. The data obtained show the autonomy of nerve tissue in the metabolic reaction of organism under any stress.

[Concentration of acid proteins in the nuclei of rat hypothalamic neuron and glial cell nuclei during cold adaptation]. / Soderzhanie kislykh belkov v iadrakh neironov i glial'nykh kletok gipotalamusa krys pri kholodovoi adaptatsii.

By means of two-wave length cytospectrophotometry the acid protein content per cell was determined in the nuclei of the neurons and their glial satellite cells of the medial peroptic area and the supraoptic nucleus of the hypothalamus of rats kept at 2--4 degrees C for 1, 3, 7, or 15 days (adaptation to cold). This colling resulted in an initial decrease in the nuclear acid protein content in the whole neuron-neuroglia system of the medail preoptic area with a gradual restoration to the normal by the 15th day of constant cooling. In the glial cells of this area the acid protein content increased temporarily above the control level before the restoration to the normal. A gradual accumulation of acid proteins and its following restoration to the control level was revealed in the neuron-neuroglia system of the supraoptic nucleus. By the 15th day of the adaptation to cold the content of neuronal and glial acid proteins of this nucleus became somewhat lower than in the control.

[Proteolytic processes in rat brain and liver during adaptation to cold]. / Proteoliticheskie protsessy v golovnom mozge i pecheni krys pri adaptatsii k kholodu.

The autolysis and the neutral proteinase activity with respect to protamine in the brain and liver of rats were studied during cold adaptation, on the 1st, 3rd, 7th, 15th, and 45th days in the cold chamber at 2--4 degrees C. A short cold effect (1--3 days) decreases the brain autolysis by 33%, the liver one by 18%. The activity of protamine-lytic peptide-hydrolase diminishes nearly by half both in the brain and in the liver. In cold-adapted rats (45 days) the autolysis increases by 50% in the brain and by 24% in the liver. The activity of neutral peptide-hydrolase remains lowered by 43% in the brain and by 36% in the liver. Thus, only autolytic processes are intensified in cold-adapted animals while the neutral peptide-hydrolase does not participate in the increasing protein catabolism in the brain and liver.