[The effect of antioxidants on in vivo and in vitro methemoglobin formation in erytrocytes of patients with Parkinson`s disease].

Methemoglobin formation was examined in erytrocytes of 16 patients with Parkinson`s disease (PD) (stage 3-4 by the Hoehn and Yahr scale). The patients receiving levodopa-containing drugs (madopar, nakom) were also treated with intramuscular injections of mexidol (daily dose 100 mg/day) for 14 days. Control group included 12 clinically healthy persons. The erythrocyte methemoglobin content was determined by electronic paramagnetic resonance (EPR) using the EPR signal intensity with g-factor 6.0. The methemoglobin content was significantly higher in erythrocytes of PD patients than in healthy donors. The complex therapy with mexidol normalized the methemoglobin content in erythrocytes of PD patients. Incubation in vitro of erythrocytes of donors and PD patients with acrolein increased the methemoglobin content, while incubation with carnosine normalized the methemoglobin content in erythrocytes of PD patients. Prophylactic (i.e. before acrolein addition) and therapeutic administration of carnosine to the incubation system with acrolein decreased the methemoglobin content to its initial level. Results of this study suggest that inclusion of the antioxidants mexidol and carnosine in the scheme of basic therapy of PD may reduce side effects associated with methemoglobinemia.

[The most important stages of the mechanism of action in vivo of carcinogen diethylnitrosoamine and its effect on the synthesis of RNA, proteins, DNA, and deoxyribonucleotides].

The mechanisms of nitric oxide (NO) generation from exogenous and endogenous sources, induced by the addition of the carcinogen diethylnitrosoamine (DENA) to rat organism have been studied. Within 15 h after the addition of DENA, the carcinogen itselt acts as an exogenous NO donor. The products of protein degradation (the process induced by DENA) act as endogenous donors of NO. It was shown that the generation of nitric oxide from diethylnitrosoamine leads to deep hemic and tissue hypoxia and induces the inactivation of oxygen-dependent enzymes, including ribonucleotide reductase, and the inhibition of ATP synthesis. Under these conditions, the protein synthesis and as a consequence the synthesis of deoxyribonucleotides and DNA are strongly suppressed; i.e., diethylnitrosoamine produces the effect similar to the action of the antibiotic cycloheximide, an inhibitor of translation. The administration of cycloheximide to the animal organism also led to the appearance of a considerable amount of nitric oxide in the blood. It is assumed that nitric oxide initiates (on the administration of the carcinogen) or at least enhances (on the administration of cycloheximide) the blockage of the synthesis of the protein, deoxyribonucleotides, and DNA. In response to the disturbance of protein synthesis, the complex of enzymes is activated that accomplish the utilization of the degradation products of proteins, including the inducible form of NO synthase.

Effect of delta sleep-inducing peptide on macromolecule biosynthesis in brain tissue of stressed rodents.

For evaluation of the nature of adaptogenic properties of delta sleep-inducing peptide we studied the effect of this substance on macromolecule biosynthesis in the brain of rats and mice exposed to burn injury and psychoemotional stress, respectively. Anabolic activity of delta sleep-inducing peptide depended on the purpose of adaptation corresponding to the type of stress.

[The mechanisms of nitric oxide production from exogenous and endogenous NO-donating compounds and its effect on deoxyribonucleotide and DNA synthesis].

The mechanisms of exogenous nitric oxide (NO) production through in vivo biotransformation of nitro-, nitroso- and amino-containing substances were discussed. In addition, the mechanisms of production and cellular sources of endogenous NO, appearing in the blood and tissues after the exposure to various DNA-damaging factors, have been considered. Considerable quantities of endogenous NO were detected in the body in the first hours after translation inhibition by cycloheximide or animal exposure to superlethal radiation doses, i.e., after the exposure to factors inducing destructive processes. The time and dose dependences of exogenous and endogenous NO production have been established. NO produced after a single or repeated administration of NO-donating compounds as well as endogenous NO proved to inhibit deoxyribonucleotide (dNTP) and DNA synthesis in animal tissues. Nonspecific compensatory responses to disturbed protein homeostasis included cyclic production of endogenous NO. The maximum levels of nitrosyl complexes were registered when the rate of protein synthesis decreased. The role of polyamines in the induction of macromolecule biosynthesis is discussed and NO production from these arginine-rich compounds is proposed. NO is released at the stage of polyamine inactivation. The inactivation mechanism includes the hydroxylation of aminogroups by NO synthase, the formation of nitroso intermediates, and their denitrosation with NO release.

[Interaction of delta sleep-inducing peptide and its analogues with cellular membranes: a structure-function analysis].

The possibility of a correlation between the membrane properties of the delta sleep-inducing peptide (DSIP) and its analogues and their biological activity in vivo was examined by a comparative study of the membrane effects of these peptides. The peptides exhibiting biological activity in vivo were shown to cause a statistically reliable disordering of lipids in thrombocyte plasma membranes similar to the effect of DSIP. The membrane effect of the D-Val2, D-Tyr2, and Tyr1, Pro2 analogues of DSIP had the same bimodal dose dependence characteristic of natural DSIP. Only a slight nonspecific lipid disordering was registered for Trp-Asp-Ala-Ser-Gly-Glu, a biologically inactive hexapeptide analogue. These results indicate a correlation between the biological activity of the peptides during in vivo tests and their membrane properties in vitro. The structure-function relationship was studied within the group of DSIP analogues examined in vitro. The DSIP modeling effect, especially pronounced under the action of stress factors, was suggested to be directly associated with the ability of DSIP to change the dynamic structure of biological membranes.

[Anabolic effect of natural and synthetic antioxidants]. / Anabolicheskii éffekt prirodnykh i sinteticheskikh antioksidantov.

The order of responses of cell systems of organs and changes in the content of some proteins of mouse and dog blood in response to addition of natural (alpha-tocopherol) and synthetic (ionol) antioxidants was studied at the whole-body level using ERP spectroscopy, radioisotope analysis, and chemiluminescence technique. Responses were evaluated by the temporary and concentration-dependence changes in the activity of ribonucleotide reductase and the rate of protein and DNA synthesis in organs of mice, as well as by the changes in the pools of Fe3+ -transferrin and Cu2+ -ceruloplasmin in blood and the antiradical activity of blood plasma of dogs and mice. During the first 24 h of exposure to alpha-tocopherol, the activity ribonucleotide reductase in bone marrow rapidly increased, whereas the activity of this enzyme and the rate of DNA synthesis in the thymus and spleen were suppressed by 30-50% compared to the control. The changes in these parameters had a phase mode with maxima on days 2-3 and 6-8. The stimulatory effect of the antioxidant on the processes of synthesis was concentration-dependent. We found that the optimal stimulation of the synthesis of deoxyribonucleotides, DNA, and protein was achieved by single administration of alpha-tocopherol at a dose of 20 mg per dog with an average weight of 15 kg and 17 mg/kg in the case of mice. Single or repetitive administration of higher doses of alpha-tocopherol was either ineffective or even suppressed the synthesis of DNA and deoxyribonucleotides. Ionol administered at a dose of 60 mg/kg increased DNA and protein synthesis in mouse organs in 2-4 and 1.2-1.5 times, respectively, compared to the control. It was also shown that single and repetitive administration of alpha-tocopherol to dogs increased the pool of Fe3+ -transferrin and Cu2+ -ceruloplasmin in blood in 2-3 times and by 20-30%, respectively, compared to the control. It is suggested that changes in Fe3+ -transferrin pool in peripheral blood may be used for evaluation of the stimulatory effect of antioxidants on the synthesis of macromolecules in organs and for the determination of dependence of this effect on the concentration of antioxidants.

[Interaction of delta-sleep-inducing peptide with cell membranes in vitro]. / Vzaimodeistvie del'ta-son-indutsiruiushchego peptida s kletochnymi membranami in vitro.

The effect of delta-sleep-inducing peptide (DSIP) on erythrocytic membranes of human donor blood was studied by the spin label and spin probe methods. The spin-labeled derivative of DSIP containing the N-terminal residue of 1-oxyl-2,2,5,5-tetramethylpyrroline-3-carboxylic acid was synthesized. An analysis of the ESR spectra of the spin-labeled DSIP derivative recorded after its incubation with a human erythrocyte suspension at 37 degrees C revealed a decrease in the rotational correlation time (tau c) and molecular order parameter (S) in comparison with the control solutions of the peptide in phosphate buffer (pH 7.4). The application of paramagnetic probes, 5-, 12-, and 16-doxylstearic acids and 3-doxylandrostanol, demonstrated that the introduction of DSIP in an erythrocytic suspension significantly increased the mobility of the hydrophobic area of the membrane bilayer both at a depth of 20-22 A and in the subsurface area (4-6 A). The dependence of these effects on the DSIP concentration was shown to have the form of a curve with well-defined extremes. The maximal disordering of membrane lipids was observed at peptide concentrations of 10(-9) and 10(-6) M. These results suggested that DSIP significantly affected the structure of plasmatic membranes in vitro by changing the physical state of their lipid components.

[Changes in the rate of protein biosynthesis in the organs of mice under the action of the delta sleep-inducing peptide and psychoemotional stress]. / Izmeneniia skorosti biosinteza belkov v organakh myshei pri deistvii del'ta-son-indutsiruiushchego peptida i psikhoémotsional'nogo stressa.

The effects of delta-sleep-inducing peptide (DSIP) and its analogs (ID-6 and ID-12) on the protein synthesis rate in the mouse brain, liver, and spleen were studied with special reference to mechanisms underlying the adaptogenic action of DSIP. Time-related changes of the protein synthesis rate were estimated in the mouse organs after a single intraperitoneal injection of the peptide (120 mg/kg body weight) and the psycho-emotional stress with or without preliminary (1 h before) injection of the peptide. After DSIP administration, the protein biosynthesis was activated and the dynamics of stress-induced changes of biosynthesis were modified. The data obtained suggest that the mechanisms underlying the DSIP adaptogenic action involve its modulatory effect on the regulatory system of protein biosynthesis.

[Changes in the intensity of free-radical reactions in the organs of rats under hypokinetic stress and with protection by the delta sleep-inducing peptide and its tyrosine-containing analog]. / Izmeneniia intensivnosti svobodnoradikal'nykh reaktsii v organakh krys pri gipokineticheskom stresse i zashchite del'ta-son-indutsiruiushchim peptidom i ego tirozinsoderzhashchim analogom.

Dynamics of the hypokinesia-induced changes of free radical and malonic dialdehyde content in brain, the changes of respiratory chain state and superoxide dismutase activity in liver of rats has been studied using ESR technique and biochemical methods. The effect of the preliminary injection of DSIP and its analogue ID-2 on these dynamics has also been studied. Using a model system constants of the interaction between DSIP or ID-2 and O2-. have been determined. The data point to the antioxidant effect of the administration of the peptides before hypokinesia. This suggests that the effect involves in mechanisms of the anti-stress action of these peptides.

[Detection of new metabolic paramagnetic centers in the lung tissue by ESR method]. / Obnaruzhenie metodom EPR novykh metabolicheskikh paramagnitnykh tsentrov v tkaniakh legkogo.

An ESR signal with g = 2.0025 and delta H = 0.2 mT was recorded at 77 K in lung tissues of guinea-pigs, mouse and rats. The signal intensity changed in the lung tissues of animals exposed to some chemicals. A relationship between new paramagnetic centres and the lung surfactant system is suggested to exist.

[Lipoxygenase activation during the development of adaptation reactions in the body]. / Aktivatsiia lipoksigenza pri razvitii adaptatsionnykh reaktsii v organizme.

Lipoxygenase activation was studied in the liver and subcutaneous connective tissue of starving mice by ESR technique. The data obtained were discussed from the view-point of possible participation of lipoxygenase activation in organism adaptation reactions.

[Changes in lipoxygenase activity in developing granulation tissue during aseptic wound healing in rats]. / Izmenenie aktivnosti lipoksigenaz v oblasti formirovaniia granuliatsionnoi tkani pri zazhivlenii asepticheskoi rany u krys.

Activation of lipoxygenases was found during development of granulation tissue in full-layer skin wound simulated in 100 Wistar rats and studied by means of electron paramagnetic resonance and high pressure liquid chromatography. Maximal activation of lipoxygenases within 2 and 6 days corresponded to two phases of wound healing: inflammation phase and phase of fibroblast proliferation during formation of the granulation tissue.

[Radiation-induced free radicals in DNA, DNA level in tissues and tissue radiosensitivity]. / Radiatsionno-indutsirovannye svobodnye radikaly DNK, soderzhanie DNK v tkaniakh i tkanevaia radiochuvstvitel'nost'.

Radiochemical yields (G-values) of H-adducts of thymine bases of DNA (TH) in frozen (77 K) gamma-irradiated mouse and rat tissues were measured. The content of DNA and the number of TH radicals formed in DNA mass of 10(12)D at a dose of 1 Gy (beta parameter) were determined for each of the studied tissue. It was shown that beta parameter, which indicated DNA in situ radiosensitivity, was different for different tissues: it was higher for radiosensitive tissues. The possible causes of the effect observed are discussed.

[Effect of ionol on oxygenase level in proliferating animal tissues]. / Vliianie ionola na soderzhanie oksigenaz v proliferiruiushchikh tkaniakh zhivotnykh.

It has been shown by low temperature ESR-spectroscopy that BHT (butylated hydroxytoluene) decreases the content of Fe2+ . . . O2 complexes being active centres of oxygenase type enzymes in loose connective tissue, regenerating liver and also in tumor and liver of tumor bearing mice. This effect is closely related to BHT presence in animal tissues.

[Free-radical disorders in the tissues of mice exposed to gamma irradiation and neutrons in vitro. The radiochemical yields]. / Svobodnoradikal'nye narusheniia v tkaniakh myshei pri deistvii gamma-oblucheniia i neitronov in vitro. Radiatsionno-khimicheskie vykhody.

The ESR method was used to study free-radical disturbances in tissues of mouse liver and spleen exposed in vitro to gamma-radiation and fission neutrons. It was shown that both types of radiation induced damages to basic chemical components of the cell, namely, DNA, lipids, proteins, and water. The radiochemical yields of each radical registered were obtained and RBE of neutrons were evaluated with a reference to the formation in tissues of radicals of each type. Membrane lipids were shown to be markedly injured by neutrons.

[Comparative study of the ESR spectra of normal and regenerating liver tissue in mice]. / Sravnitel'noe izuchenie spektrov EPR tkanei normal'noi i regeneriruiushchei pecheni myshei.

Low temperature ESR spectra of gamma-irradiated samples of mouse liver regenerating after partial hepatectomy were studied. As compared to ESR spectra of gamma-irradiated samples of health animals liver, in regenerating liver samples new ESR signals from paramagnetic centres S(2.0005) and S(2.0025) were revealed; these signals were earlier recorded by the authors in gamma-irradiated samples of hepatoma 22a. It is concluded that the paramagnetic centres S(2.0005) and S(2.0025) are typical of proliferating tissues of different ethiology.