[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.

[The effect of pyrazidole on monoamine level in hypobaric hypoxia]. / Vliianie pirazidola na soderzhanie monoaminov pri gipobaricheskoi gipoksii.

Increase of serotonin content and decrease in 5-hydroxyindolyl acetic acid (5-HIAA) were observed under hypoxic conditions (9,000 m, 3 hrs) which correlated with inhibition of monoamine oxidase A. Administration of the monoamine oxidase inhibitor pyrazidole caused the more pronounced increase of serotonin levels and decrease of 5-HIAA in control animals as well as in hypoxic animals. The catecholamines increased in hypoxia, pretreatment with pyrazidole prevented this increase. Preliminary administration of pyrazidole also increased the content of blood catecholamines, which reduced in hypoxia. Pyrazidole exhibited the antistress effect as the drug inhibited a decrease in adrenal ascorbic acid levels in hypoxic conditions.

[The effect of pyrazidol on animal status and on the monoamine level in periodic hypobaric hypoxia]. / Vliianie pirazidola na sostoianie zhivotnykh i soderzhanie monoaminov pri periodicheskoi gipobaricheskoi gipoksii.

The effects of 3 and 10-day intermittent hypoxia corresponding to the altitude 5000 m, during 4 hrs a day, were studied. Daily administration of pyrazidol exerted a normalising effect on the plasma total peroxidase activity, extra erythrocyte hemoglobin concentration and adrenal ascorbic acid content. Unprotected rats developed a 2-fold reduction of the body mass under the 10-day hypoxia. Administration of pyrazidol normalises catecholamines content in the hypothalamus and brain cortex in the 3-day hypoxia, prevents a monoamine content decrease in the hypothalamus and adrenals in the 10-day hypoxia, promotes a serotonin increase in the brain areas. Adrenal norepinephrine content was twice as large in the protected animals than in unprotected those. An adaptogenic role of pyrazidol under conditions of an intermittent hypoxia is discussed.

[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 pyrazidol on resistance of animals to hypobaric hypoxia]. / Vliianie pirazidola na ustoichivost' zhivotnykh k gipobaricheskoi gipoksii.

The influence of monoamine oxidase type A inhibitor pyrazidol on rats sensitivity to hypobaric hypoxia was investigated. Preliminary pyrazidol administration shows evident protective effect under hypoxia. It increases animals survival at the altitude of 12,000 m above the sea level, prevents lungs affection and erythrocyte membrane destabilization at the altitude of 9,000 m during 3 hours. Plasma total peroxidase activity, extraerythrocyte hemoglobin concentration and free iron content were used as the indexes of erythrocyte membrane stability reflecting the organism state under stress effects.

[The use of pyrazidol during treatment using hyperbaric oxygenation therapy]. / Ispol'zovanie pirazidola pri lechenii metodom giperbarooksigenoterapii.

The effect of pyrazidol on the efficiency of hyperbaric oxygenation (HBO) was investigated. Pyrazidol administration before HBO procedure reduced the intensity of lipid peroxidation in the blood plasma and decreased destabilization of erythrocyte membranes. Exoerythrocyte hemoglobin concentration, total peroxidase activity and glucose-6-phosphate dehydrogenase activity were used as the indexes of membrane stability. The patients pretreated with pyrazidol bore HBO much better than other patients.

[Effect of polyamines on indices of oxygen toxicity in rats]. / Vliianie poliaminov na pokazateli kislorodnoi intoksikatsii u krys.

The intraperitoneal administration of polyamines to rats before hyperbaric oxygenation decreases the rate of development of hyperoxic convulsions, prevents lung edema and stabilizes blood cell membranes.

[Monoamine oxidase activity and brain levels of histamine and polyamines in various extreme exposures]. / Monoaminoksidaznaia aktivnost' i soderzhanie gistamina i poliaminov mozga pri nekotorykh ékstremal'nykh vozdeistviiakh.

The activity and kinetic properties of monoaminoxidase, the level of histamine and polyamines are studied under three extreme factors--hyperoxia, hypoxia and cold stress. The similarity of the metabolic responses of the organism to the investigated extreme factors is shown. All studied parameters indicate that the selected regime of hyperoxia has the most negative effect on the organism; hypoxia has the slightest effect and cold stress takes an intermediate position.

[Effect of clorgyline on the intensity of lipid peroxidation and on erythrocyte membrane stability in hyperoxia]. / Vliianie khlorgilina na intensivnost' perekisnogo okisleniia lipidov i stabil'nost' éritrotsitarykh membran pri giperoksii.

Administration of monoamine oxidase type A inhibitor clorgyline to rats before hyperoxia prevented oxygen-induced increase in diene conjugate and Shiff's base brain and plasma levels in hyperoxia. This was due to antioxidative effect of clorgyline which resulted in stabilization of blood cellular membranes. Clorgyline had a normalizing effect on extraerythrocyte hemoglobin level, total peroxidase activity and glucose-6-phosphate dehydrogenase activity in the serum.

[Monoamine oxidase activity and effect of clorgyline on the polyamine level during hyperoxia in rats]. / Monoaminoksidaznaia aktivnost' i vliianie khlorgilina na uroven' poliaminov pri giperoksii u krys.

During hyperoxia monoamine oxidase type A acquires the ability to deaminate polyamines and histamine. A preliminary injection of clorgyline (a monoamine oxidase type A inhibitor) before hyperoxic exposure leads to a significant removal of oxygen seizures and prevents changes in the cerebral spermidine and histamine content observed in the unprotected animals. The data confirm the important role of modification of catalytic properties in monoamine oxidase in the mechanism of oxygen intoxication.

[Links in the histamine metabolism in the brain of rats with sequential exposure to low- and high-pressure oxygen]. / Nekotorye zven'ia obmena gistamina v mozge krys pri posledovatel'nom deistvii nizkogo i vysokogo davleniia kisloroda.

Histamine content and diamine oxidase activity in rat brain under hyperbaric oxygenation have been studied. Under 0,3 MPa histamine level decreases in brain of more sensitive rats, but it does not change in brain of more resistant animals in comparison with the control ones. High oxygen pressure (0,7 MPa) causes a significant increase of histamine concentration. Diamine oxidase activity decreases under hyperoxia. Under the consequent action of high and low pressure (0,3 MPa during 1 h and 0,7 MPa) convulsions in rats begin later and alterations of histamine content in brain are less than under 0,7 MPa oxygen action only. The role of histamine at compensate reaction and cause of increasing resistance of animals to hyperoxia are discussed.

[Monoamine oxidase and diamine oxidase activity of the tissues of rats in the convulsive phase of oxygen poisoning]. / Aktivnost' monoaminoksidazy i diaminoksidazy v tkaniakh krys v sudorozhnuiu fazu kislorodnoi intoksikatsii.

Monoamine oxidase type A activity with substrate serotonine and type B with substrate p-nitrophenylethylamine decreases is rats' brain, liver, heart and blood during oxygen convulsions. Substrate specificity of the enzyme type A alters in all tissues studied. Diamine oxidase activity decreases in brain, lungs and liver approximately in 2 times and increases in blood at 48%. Histamine content increases in all tissues in 3-4 times, in blood--in 12 times. The role of observed changes in the mechanism of oxygen intoxication is discussed.

[Age and the role of certain mediators in the sensitivity of animals to hyperbaric oxygenation]. / Rol' nekotorykh mediatorov v vozrastnoi chuvstvitel'nosti zhivotnykh k giperbaricheskoi oksigenatsii.

Dynamics of biologically active brain peptides: N-acetyl-1-aspartat-1-glutamat (NAAG) and homocarnosine (gamma-aminobutyric-1-histidine), aminoacids and their derivatives GABA, histidine and histamine, in the blood of rats and rabbits of different age under hyperoxia was studied. Exposure of animals to 4 atm of oxygen considerably decreased NAA and NAAG contents in the brain of 21 and 30-day old rats and induced the 85% and 47% decrease of homocarnosine and GABA contents respectively in the brain of 30-day old rabbits. Brain histidine and blood histamine contents increased in 14, 21 and 30-day old rabbits.