Effect of plastoquinone derivative 10-(6'-plastoquinonyl) decyltriphenylphosphonium (SkQ1) on estrous cycle and 17ß-estradiol level in rats.

Administration of the plastoquinone derivative 10-(6'-plastoquinonyl)decyltriphenylphosphonium (SkQ1) to female Wistar rats with regular estrous cycle once a day for two weeks at doses of 25 nmol/kg (but not 250 nmol/kg) leads to increase in proestrus duration by reducing the phase of diestrus and metestrus. Neither dose caused significant changes in serum 17ß-estradiol level for any stage of the cycle. However, relative elongation of the proestrus stage leads to an increase in average per cycle estradiol levels by 20%.

[Chemiluminescence analysis of oil oxidizing bacteria Actinetobacter calcoaceticus extracts: effects of the extracts on pSoxS-lux biosensor].

A comparative H2O2-luminol- and Fe(II)-induced chemiluminescence analysis of extracts of two strains of marine oil oxidizing bacteria Actinetobacter calcoaceticus cultivated either in the presence or absence of oil was carried out. Effects of these extracts on E. coli MG1655 biosensor (pSoxS-lux) were studied. Activation of H2O2-induced chemiluminescence in the presence of oil was observed. This suggests activation of free radical lipid peroxidation. Aqueous extracts of microorganisms cultivated in the presence of oil were shown to activate reactive oxygen species production (ROS) in Fe(II)-induced chemiluminescence reaction mixture. Acetone-ethanol extracts induced antioxidative systems of both strains. Chemiluminescence analysis in a biological system carried utilizing E. coli MG1655 (pSoxS-lux) revealed that aqueous extracts of the strains cultivated in the absence of oil contained potential antioxidants.

Effect of plastoquinone derivative 10-(6'-plastoquinonyl)decyltriphenylphosphonium (SkQ1) on contents of steroid hormones and NO level in rats.

Introduction of the plastoquinone derivative 10-(6'-plastoquinonyl)decyltriphenylphosphonium (SkQ1) into male Wistar rats once a day for two weeks in doses of 25 and 250 nmol/kg led to elevation of 17ß-estradiol level in blood serum by 33 and 41%, respectively. At the same time, nitrate and nitrite contents in the rat blood serum increased by 49 and 34%, respectively. ESR spectroscopy with diethyldithiocarbamateiron complex as a spin trap showed more than twofold increase in NO production in lungs, but not in blood, liver, and intestines, following the SkQ1 daily introduction at a dose of 25 nmol/kg.

[Influence of infrared cold laser radiation emission on free radical processes in various tissues of rats with circulatory cerebral hypoxia].

Influence of infrared cold laser emission (IRCL) on the dynamic equilibrium between lipid peroxidation and tension of the antioxidant defense system in rat's tissues (blood, brain, retina, cornea) was evaluated in animals with circulatory cerebral hypoxia induced by occlusion of the left carotid artery. Tissues of white rats were examined for IRCL effects on hemiluminescence, malonic dialdehyde, SOD and catalase activities on the background of circulatory cerebral hypoxia. Data of the experiment evidenced an antioxidant effect of posthypoxic IRCL therapy as it reduces intensity of the free radical processes in plasma, cerebral tissues and retina. The experiment demonstrated the IRCL ability to modulate LPO, to stiffen the antioxidant defense system in the event of eye diseases originated from circulatory hypoxia of the ocular analyzer.

[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.

[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.

[Biochemical indicators of oxygen poisoning]. / Biokhimicheskie pokazaniia kislorodnoi intoksikatsii.

Content of extra erythrocyte hemoglobin (EEH), total peroxidase activity (TPA), tseruloplasmin oxidase activity (TOA) and chemiluminescence intensity have been investigated in plasma. The dose-dependent changes of EEN, TPA, TOA are shown in experiments on the animals under hyperbaric oxygen (HBO) pressure (0.2, 0.3, 0.5, 0.7 MPa from 30 min. to 120 min.) and EEH, TPA--under hyperbaric air (1.1 MPa; 4 hours). All these parameters have been studied in patients treated with HBO for the assessment of HBO efficacy in the clinical investigations. These biochemical parameters may be used as informative tests of the functional state of the organism under HBO and hyperbaric air.

[The quantitative assessment of the level of the emotional stability of an operator specialist]. / Kolichestvennaia otsenka urovnia émotsional'noi ustoichivosti spetsialista-operatora.

A methodical approach to appreciation of the emotional stability of specialists-operators was experimentally approved, carrying out standard tests at the simulator of various extreme situations. The authors worked out a quantitative formula for appreciation of emotional stability, making use of the initial data obtained in standard tests carried out by operator in drill, optimum and extreme variants. There is a scale that includes five categories of emotional stability (high, relatively high, middle, relatively low, low). A special methodical approach is recommended to detect emotionally unstable operators (or candidates for these posts), and also for an a priori prognostication of the operators' activities in stress situations.

[Dosimetric characteristics of the prodromal radiation syndrome]. / Dozimetricheskie kharakteristiki prodromal'nogo luchevogo sindroma.

Main symptoms of the prodromal radiation syndrome have been investigated. The results of clinical observations shown that the probability of displaying the prodromal syndrome is a function of radiation dose.