[Alpha-lipoic--dihydrolipoic acids--active bioantioxidant and bioregulatory system]

alpha-Lipoic (LA) acid (thioctic acid) is an intramolecular disulfide that may be simply endogenically turned into dithiol. Dihydrolipoic acid (DHLA)/ LA and DHLA are bioantioxidants. They are synthesized in the body and taken with diet. Water- and lipide-soluble LA is highly-effective against the reactive oxygen species. LA (DHLA) protect the biomembranes, mitochondria from oxidative stresses of various kinds. LA, DHLA and lipoamide function as cofactors of polyenzyme mitochondrial complexes of 2-oxoacid dehydrogenases, of glycin decarboxylases and of some other enzymes. LA (DHLA) is ubiquinone reactivator and synergist by vitamin A, C, E. LA optimizes glucose metabolism, it is effective in insulin-resistant diabetes and its complications, in neutopathies and neurodegenerative diseases.

[Role of oxidative stress in pathogenesis of atherosclerosis and ischemic heart disease]

New views concerning the role of oxidative stress in pathogenesis of atherosclerosis and ischaemic heart disease have been summarized in literature review, possible approaches to their pharmacologic correction taking into account metabolic imbalances caused by oxidative stress have been considered here.

[Decrease of mutagenic action of cyclophosphamide by buckwheat melanin preparation]

Melanins are polyphenolic pigments of plants, animals and microbes with antioxidant and antiradiation activity. Water-soluble melanin from buckwheat is experienced as antimutagenic means (0.01-10 mg/kg per os) for cyclophosphamide (20 mg/kg i.p.) in the 3 series of experiments. The frequency of chromosome aberrations in the cells of mice bone marrow after mutagene is reduced 2-6 times once under influence of melanin.

[Selenium: the biological role and antioxidant activity]

Selenium is essential trace element, sulphur analogue with high chemical activity, component of some selenoproteins and enzymes: glutathione peroxidase and other peroxidases, blood and tissue proteins. As to their biological action mechanism selenium and its compounds are antioxidants. Selenium is active immunomodulator, much more potent anti-oxidant than vitamins E, C and A, beta-carotene, but much more toxic. It takes part in thyroxine conversion to triiodethyronine in thyroid hormone biosynthesis. As sperm antioxidant selenium protected its motility and fertility. Selenium is a serious factor of biological and antioxidant protection of vascular endothelium, of low-density lipoproteins, protection of DNA, chromosomes. As food component selenium is an exceptional agent of protection from atherosclerosis, coronary ischemic disease and cancer. Some hydrobionts, liver, kidney, meal, corn and garlic, onion, cabbage, broccoli are dietary products with high content of selenium.

[Metallothioneins: the structure and mechanisms of action]

Metallothioneins (MT)--4 groups (MT-I, II, III and IV) of low molecular mass (approximately 6.5 kDa, 61-62 amino acid residues) cytosol proteins. They are rich in sulphur--20 residues for cysteine, are found in cytosol and nuclei of eucaryotic cells. MT-I and MT-II are found in all animal tissues, MT-III and MT-IV--in the brain. The functions of MT are regulation and control of redox-homeostasis, thioldisulphide equilibrium in the cell in synergism with GSH. MT molecule involve two domains, alpha and beta. MT gene promoter have response elements to metals (MRE), to glucocorticoids (GRE) and to oxidative agents, electrophilic compounds and xenobiotics (ARE). Expression and synthesis of MT are induced for heavy metals (Zn, Cu, Cd and so Hg, Pb, As, Ni, Ag a.o.); glucocorticoids and other stress-hormones and cytokines; free radicals, peroxides, cancerogens and antitumor drugs, UV and ionizing radiation. Zn and partially Cu are physiological inductors of MT. Other inductors act more or less actively as stress-agents. Zinc stabilizes MT molecule, enhances some of their functional activities as a scavenger of metal ions, of free radicals, toxins and xenobiotics. MT are exceptional protection agents for embryo and adult from Cd and other heavy metals, from ionizing radiation, cancerogens, alkylating and DNA-linked agents, from oxidative stress. MT realizes negative control of immune system functions, of transcription factor NF-kB activity. The use of genetic engineering achievements (transgenic mice with defective MTF-1-genes and MT-overexpressing genes) enlarge the possibilities of MT study and application.

[Propofol--new highly effective intravenous anesthetic]

A review is presented of revelant medical literature concerning potentialities of a new intravenous anaesthetic propofol that has come into widespread use as a means of inducing and maintaining anaesthesia, short-term and long-term sedation. Propofol allows an extremely prompt induction of anaesthesia and postanaesthetic recovery to be achieved, with the depth of anaesthesia easily controlled.

[Effect of hypergravity on the oxidative-antioxidative status of rats]

The adaptogenic and antioxidant properties of new Ukrainian plant drug "Poliphytolum" was investigated on the model of stress, which was caused of hypergravitation 2 and 5 N.m2/kg2 action. It was established that hypergravitation makes typical stressory disturbances in oxidative homeostasis. The normalization action of "Polyphytolum" on lipid peroxidation is more strong in liver, spleen and blood, and less more--in brain. It may be caused of low level the drug in the brain tissue.

[Effect of splenosid on lipid peroxidation process and glutathione antioxidant system in rats exposed to fractionated radiation]

The dynamics of lipid peroxidation, antioxidant glutathione system condition in blood and viscerals (brain, heart, liver, spleen) of rats which were fractionally irradiated (10 fractions) in the total dose 1.0 Gy and oxidative homeostasis increase of primary and secondary lipid peroxidation products and glutathione system disturbances were established in the irradiated rats. The administration of splenosid diminished the disturbances of oxidative homeostasis but does not completely normalize the latter. The administration of splenosid during the irradiation course and after its finishing is more effective than only during the irradiation course.

[Antioxidant and biological activity of melatonin]

Neurohormone melatonin controls the circadian rhytmicity of some biological processes, unites the functions of nervous, endocrine and immune systems. Melatonin is a powerful bioantioxidant, capable to be dissolved in water and lipids, runs through membranes and barriers, accumulates in cell nuclei and protects DNA from oxidative stress. Melatonin displays immunomodulating, radioprotective and antitumor activities.

[Melanin: structure, biosynthesis, biological functions]

Melanins are the group of natural black pigments. The structure of melanin macromolecules is irregular network arising from phenolic precursors in consequence of enzymatic and autooxidation. Melanin is stable polyradical, contain some semiquinone radicals and accumulate the exogene radicals and other active oxygen species, heavy metals, electrophyl toxic compounds. Some this properties determine the antioxidant, antitoxic, antiradiation and antitumour activity of melanins. On the base of natural melanins is possible creation of some effective prophylactic and curative preparations.

[Stress in the etiology of radiation injury. Role of regulatory mechanisms]

Radiation damage as stress is regarded in the review. The place of lipid peroxidation in the starting of stress reaction and the possibility of the application of antioxidants and thymus preparations as factors which lower the hardness of radiation damage are considered.

[Mechanism of the antistressor and antiradiation action of plant phenol compounds]

The article analyses critically the date from literature as well as own date concerning appropriateness and mechanisms of antiradiation, capillary strengthening and antistress effect of plant phenolic compounds. Knowledge on antioxidant effect as the most fundamental mechanism being in the basic of the above mentioned biologic effects of plant phenolic compounds is grounded.

[Biochemical mechanisms of acquired radioresistance of tumor tissue]

The level of lipoperoxidation products in radioresistant tumour is 3 times lower and superoxide dismutase activity--3.5 times higher than in the intact tumour. That is an evidence of high stability. The level of lipoperoxidation products in the brain and liver of rats with radioresistant variant of Guerin carcinoma is essentially less and catalase activity--considerably higher, than in the rats with intact tumour. This evidences for the corresponding increase of antioxidant protection of the organisms in the process of acquiring the tumour radioresistance.

[Thiol group content in blood serum and in tumor tissue of rats with intact and radioresistant variants of Guerin carcinoma]

Interrelation between the formation of the secondary acquired radioresistance of Guerin carcinoma cells and dynamics of content of thiol groups in the tumour tissue and blood serum of rats have been studies. It is established that the tumour tissue and normal tissues (blood serum) of rats with Guerin's carcinoma respond to the fractional radiation action and to repeated courses of radiation therapy by the reactive increase of the number of free non-protein thiol groups and by the decrease of the content of protein thiols. The use of local superhigh-frequency-hypothermia in the pattern of treatment of the Guerin carcinoma strain resistant to irradiation is accompanied by the increase of the reaction capacity of non-protein thiol groups of the tumour tissue. At the same time the level of general thiol groups in the blood serum decreases while their reactivity increases.

[Correction of radiation injuries caused by low-intensity irradiation using antioxidants]

The appearance of active oxygen form beginning and lipid peroxidation's activation (side by side with DNA injury) play the leading role in the mechanism of radiation injury. It is expedient to use antioxydants as prophylactic and early pathogenetic therapy remedies. The paper includes the survey of data from literature about usage of different classes of antioxidants (enzymes, vitamins, thiols and other) during prolonged low intensive radiation action.

[Dynamics of lipid peroxidation in blood and organs of rats after irradiation at low doses and the effect of antioxidants]

A study was made of the dynamics of lipid peroxidation (LPO) in rats after the whole-body 1.0 Gy X-irradiation (ten fractions of 0.1 Gy at a 24-hour interval; 0.425 R/min) and the possibility of correction LPO with alpha-tocopherylacetate, ascorbic acid and catechin complex by means of a single and combined administration. The accumulation of primary and secondary LPO products in blood, radiosensitive (spleen and mucosa of small intestine) and radioresistant (brain) organs is established. The administration of mentioned antioxidants diminishes the content LPO products, but does not completely normalize the latter. Administration of antioxidant complex was most effective.

[The antistressor action of dibunol in surgical stress in lung cancer patients]

Dibunol (butylhydroxytoluene) in 1-g capsules was given to lung cancer patients, 4 g for two days and 4 g for one day before surgery. The level of stress was evaluated by the blood levels of cortisole, by the daily urinary concentrations of 17-keto- and 17-ketogenic steroids, and by the blood levels medium-weight molecular peptides and toxic indices 1, 3, 5-7 days of postsurgery. The antistress action of the agent appeared as twofold decreased blood cortisol and urinary 17-KS and 17-KGS 1 day after surgery, returning to the baseline on day 3 (while there was no normalization even on day 7 if dibunol was not given), and as significantly declined intoxication indices.

[Radiation protective effect of low molecular weight thymus preparations]

The antiradiation efficiency of low molecular thymic preparations (vilosen, thymogen) was determined. The therapeutic activity of thymic preparations is due to their influence on basic radiation injury syndromes (hemopoietic, gastrointestinal, immunodepressive). The protective mechanisms and perspectives of thymic preparations using in pathogenic therapy of radiation diseases are discussed.

[The prevention of surgical stress in lung cancer patients with the antioxidant dibunol]

Dibunol was administered 48 and 24 hours before the operation at a dose of 4 g using capsules of 1 g each, in lung cancer patients. Stress severity was judged from the blood content of hydrocortisone, 17-keto- and 17-ketogenic steroids in 24-h urine, the content of mid-molecular weight peptides and indicators of intoxication before the operation and at 1, 3 and 5-7 day following it. Stress-protective effect of dibunol was manifested by almost 2-fold reduction in the blood hydrocortisone, urine 17-KS and 17-KGS/24 h levels following the operation, and by return of these parameters to baseline level at day 3 (whilst without dibunal no normalization occurred even at day 5-7), as well as by an appreciable lowering of the parameters characterizing intoxication.

[The effect of low doses of long-term internal irradiation on the ultrastructure and intensity of lipid peroxidation in rat brain and blood]

Rats were administered with the mixture of 137Cs and 85Sr for 30, 56 and 90 days. Dynamic of ultrastructural changes of lipid peroxidation has been studied in cerebrum and blood. Maximum biochemical changes have been detected after radionuclide administration for 30 days (increase in spontaneous chemiluminescence intensity and quantity of TBA-active products). Under further administration lipid peroxidation parameters as well as radionuclide content in blood and organs were sufficiently stable, while ultrastructural changes were in progress during the influence.

[Prooxidant link of oxidative homeostasis under low doses of ionizing radiation of low intensity]

Peculiarities of the processes of lipids peroxidation under effect of ionizing radiation in small doses and its low intensity have been considered. Data from literature concerning the threshold doses of lipids peroxidation activation have been generalized.

[Oxygen-dependent processes in the irradiated organism]

Interaction of oxygen with the X-rayed tissues, chemical substances and elements is one of the main mechanism of radioactive damage. Radiosensibilization by oxygen (oxygen effect) is most highly exhibited under the action of high and moderate radiation doses. However there is only scanty investigations and information about oxygen-dependent processes under low doses of internal and external radiation due to their intricate character. Radiation exerts also a great influence on oxygen metabolism and oxygen consumption level. Oxygen takes active part in post-radiation recovery both at the level of molecules, organelles, cells, tissues, organs and the organism on the whole. The partial pressure of oxygen and its content have a great influence on the action of radioprotectors, anti-radiation therapy and healing methods. Long-term influence of hypoxia at high altitude evokes adaptation changes, stimulates recovery processes in an X-rayed organism, increases resistance to radiation and other noxious factors.

[Pro-oxidant and antioxidant homeostasis in guinea pigs following fractionated x-ray irradiation at low doses and the correction of disorders with an antioxidant complex]

The state of pro-oxidant-antioxidant homeostasis in guinea pigs exposed to whole-body fractionated X irradiation (5 fractions of 0.2 Gy at a 24 hr interval, up to total dose of 1.0 Gy, at a dose rate of 0.425 R/min) and a possibility of its disturbance correction with the complex of vitamins C, E and P was studied. Accumulation of primary and secondary lipid peroxidation products, decrease of the ascorbic acid content, increase of the content of its oxidized forms (dehydroascorbic acid and diketogulonic acid) in radiosensitive (spleen and small intestine) and radioresistant organs were found. Antioxidant complex administration reduced the disturbances of pro-oxidant-antioxidant homeostasis, but did not provide complete normalization.

[Effect of ionizing radiation on central nervous system]

Main properties of ionizing radiation as a factor affecting the organism are described. Data on molecular and cellular mechanisms of the radiation injury of the central nervous system, impacts of the radioactive irradiation on the vascular system of the brain adn on a hematoencephalitic barrier, a system effect of radiation on the brain are discussed.

[Radioprotective effect of Corynebacterium michiganense polysaccharide]

Antiradiation activity of polysaccharide isolated from phytopathogenic coryneform bacteria Corynebacterium michiganense has been established. It is shown that the introduction of polysaccharide immediately or 2 h after irradiation with the lethal dose promotes maximum survivability of experimental animals (30 and 20%, respectively).

[Effectiveness of correcting radiation injuries of the thymic endocrine function by T-activin in conditions of reduced postradiation hypercorticism reaction]

T-activin administered to rats after exposure to whole-body 1.5 Gy neutron- and 6 Gy X-radiation increases considerably the thymosin-like serum activity, accelerates cellularity restoration in the thymus and spleen, but does not influence the survival rate. Ionol administered prior to X-irradiation reduces the postirradiation hypercorticism reaction and the indirect effect of radiation on lymphoid organs which it is responsible for. The combined injection of ionol and T-activin increases the thymosin-like serum activity and spleen cellularity to the highest possible level and increases the survival rate of rats from 24 to 64 per cent and the lifespan up to 6 days.

[The triboluminescence of the blood and the brain cellular elements in rats exposed to X irradiation in doses causing bone marrow, intestinal and cerebral syndromes]

Triboluminescence of blood and brain cells (neurons and neuroglia) in bone marrow, intestinal and cerebral radiation syndromes has been investigated. Dynamics of triboluminescence intensity of neurons and glial cells after irradiation (0.013, 0.31 and 3.87 C/kg) is the same with that of blood triboluminescence.

[Interaction of very low density lipoproteins (VLDL) with macrophages and their triboluminescence in hypercholesterolemia]

Accumulation of cholesterol esters and triglycerides in peritoneal mice macrophages in the course of their interaction with lipoproteins of very low density (VLDL) is shown to grow considerably under conditions of hypercholesterolemia. A decrease of triboluminescence intensity characterizing the surface charge has been revealed at hypercholesterolemia both in VLDL and in the blood plasma. It is supposed that the triboluminescence method may be used for testing of the atherosclerotic process development.

[The use of ceruloplasmin in combination with adjuvant polychemotherapy in stomach cancer]

Ceruloplasmin as a modulator was used for the first time in the clinical practice in 30 patients with gastric cancer in the course of postoperative intraabdominal adjuvant chemotherapy. It was established that ceruloplasmin was well tolerated by the patients and its use during polychemotherapy is accompanied by normalization of the levels of natural ceruloplasmin and iron in the blood serum that are usually reduced in patients with gastric cancer, reduces activation of lipid peroxidation and improves the course of postoperative period. Ceruloplasmin possesses a week immunomodulating action in polychemotherapy which is expressed in the increase of the percentage content of T-lymphocytes. Use of ceruloplasmin tended to improve the functional state of the cardiovascular system.

[Triboluminescence of the blood in mice during immunization and the administration of thymic hormonal factors]

Triboluminescence (TrL) is optical radiation, arising at the expense of energy of free radical oxidation (in mechanochemical influence) and electrophysical processes in the cell membranes of blood. Under the influence of immunization a decrease of cell membrane polarization is observed. Administration of thymic agents (vilosen and tactivin) into intact and immunized animals decreases the TrL intensity as well, that could be considered as manifestation of their antioxidant effects.

[Dynamics of the indices of lipid peroxidation in the blood and radiosensitive organs of rats exposed to total and local x-irradiation]

There are variations in the radiation response of lipid peroxidation (LPO) indices. The initial rise of spontaneous chemiluminescence (SCL) immediately after whole-body irradiation (8 Gy) is followed by its rapid drop below the initial level. A considerable increase of the LPO level in the blood, spleen and thymus occurs 24 hr or 2 days after irradiation. The decrease on day 7 is followed by the increase on day 14. The periods of LPO inhibition (15 to 60 min and 7 days after irradiation) correspond to two waves of the hypersecretion of catecholamines and glucocorticoids that have antioxidant activity. With local irradiation of rat skin (a single exposure to 50 Gy) the SCL and malondialdehyde intensity peaks in blood serum are the same as those observed after whole-body irradiation, whereas in the spleen and thymus, these indices regularly decrease. There are peculiarities in the dynamics of triboluminescence in rat blood and organs that is attributed, in addition to LPO, to the effect of radiation on the electric parameters of tissues.

[Postradiation changes in the functioning of the systems of lipid peroxidation and phospholipase hydrolysis in the cellular formations of the brain]

A study was made of the effect of irradiation with lethal and superlethal doses on lipid peroxidation and endogenous phospholipase hydrolysis in the enriched fractions of neurons and glia. Severe and irreversible changes occurred in a lipid membrane component of both neuronal and glial fractions of the brain under the effect of ionizing radiation.

[Radiobiology and the lessons of Chernobyl]

The Chernobyl accident has marked the beginning of a new stage of radiobiology development and revealed scantiness of old concepts. One should (1) search for effective protectors against the long-term influence of low-level radiation and means of removal of radionuclides using criteria that differ principally from those used previously in selecting among nontoxic antioxidants, immunomodulators, and adaptogens; (2) study systematically the synergism of low doses of harmful agents and review the hygienic standardization system with due regard for the risk from their combinations; (3) consider comprehensively, on the basis of the experimental and clinical experience, the problem of "hot" particles and remote consequences of their influence on the respiratory and digestive systems; (4) study independently the problem of chronic stress as a combination of radiation effects and psycho-emotional consequences of the accident and living in the exposed areas; (5) consider it inadmissible to include in the B category the population of the districts influenced by the accident and to use the concept: "35 rads during the lifetime" in standardizing the radiation load; (6) organize a comprehensive analysis of the Chernobyl accident consequences for public health within the contaminated areas as well as for animals and plants using a single approved methodology and programme, the principle of "other equal conditions" being provided.

[The ability of peripheral blood lymphocytes to repair DNA and the survival of rats]

Individual and group differences were revealed in the capacity of rat peripheral blood lymphocytes of DNA repair in response to the DNA damaging test-effect of irradiation in vitro. The survival rate of rats irradiated with a dose inducing 50-per cent death was in a definite relationship with the repair capacity of blood lymphocyte DNA in each animal individual prior to irradiation.

[The role of lipid peroxidation in the mechanism of stress]

A concept on the mechanism of stress response is substantiated proceeding from the data available in literature and obtained from the author's research made on the radiation stress model. The conception envisages that products of lipid peroxidation (LPO) appear as primary (under direct effect of a stress factor on tissues) and secondary (as a consequence of high- and long-term catecholamine++) mediators. Mobilization of stress-realizing systems in that process is regarded as an adequate response of the auto-oxidative++ system to the primary activation of LPO. Transformation of catecholamines into the factor of LPO stimulation (secondary) is a result of an increase in the relative role of the quinoid way to transform catecholamines in the case of their high concentration. Radical intermediates of the quinoid metabolism appear as LPO initiators. An important pathogenetic role of LPO activation in the stress mechanism substantiates expedience to use antioxidants as agents for prophylaxis and early treatment of stress-factor injuries.

[Antioxidant effect of the antineoplastic antibiotic obtained from a plant of the family Asteraceae]

Antitumour antibiotic from a plant of the family Asteracea has been studied for the biochemical mechanism of its action. Redox processes were tested by the method of spontaneous chemiluminescence determining the intensity of freely radical oxidation of membrane cell phospholipids. It was established that the antibiotic under study stabilized the indices of spontaneous chemiluminescence up to the normal level.

[Comparative action of X-rays and fast neutrons on thymus endocrine function]

Whole-body exposure of rats to X-rays (4, 6 and 8 Gy) and neutron radiation (1, 1.5 and 2 Gy) causes a dose-dependent inhibition of endocrine function of thymus and death of its lymphoid cells. Shielding of thymus somewhat reduces the degree and duration of inhibition of thymus hormone secretion.

[An experimental analysis of the interrelation of the kinetics of spontaneous blood serum chemiluminescence and of the kinetics of the tumor process]

On the material of 5 strains of transplanted rat tumours (sarcoma 45, carcinoma Guérin, carcinosarcoma Walker, lymphosarcoma Pliss, erythromyelosis Shvets) and also mice tumours induced by Moloney and Rauscher viruses and on the models of chemical carcinogenesis of rats: lung (intratracheal injection of 3,4-benz(a)pyrene), breast (DMBA) and liver DENA) was shown that tumorous processes of various origin are accompanied by either elevation or inhibition of blood serum spontaneous chemiluminescence (SChL). In all investigated cases the extreme points of SChL curve coincide with the moment of change of tumour growth kinetics.

[Intensity of triboluminescence of rat blood during total gamma-irradiation]

Rat blood triboluminescence resulting from the effect of triboelectrization and activation of free-radical oxidation was studied 15 min to 14 days following gamma-irradiation with doses of 1, 2, 4, 6, 8. and 16 Gy at an original device (triboluminometer TPA-1) in standard conditions of luminescence generation with a contact of the blood sample with a rotating cylinder. Triboluminescence of blood decreased 1-3 days following irradiation and was restored up to the initial level after 7-14 days. Triboluminescence intensity somewhat increased 1-3 days following 1 Gy irradiation.

[Reliability of autoregulatory mechanisms of biosystems as affected by ionizing radiation]

Reliability of biosystems in processes of adaptation and homeostasis after whole-body irradiation of rats with different doses was determined in terms of the stochastic process theory developed for the autoregulatory systems with random parameters. Fluctuations in the rate of spontaneous chemiluminescence of blood serum and accumulation of lipid peroxidation products by erythrocyte membranes of rat blood were taken as the initial material. The analysis of fluctuations of peculiar parameters permitted to predict the adaptability of the system and to make timely corrections.

[The problem of peroxidation in radiobiology]

A hypothesis is validated concerning the products of free radical oxidation of lipids and the phenol compounds as a mediator unit of the stress-syndrome. The data are reviewed on activation of peroxidation under the effect of radiation, cytochemical agents, etc., secondarily stimulating the neurohumoral system function of homeostasis regulation. With the emotional-algesic and cold-stresses, the regulatory system stimulation is of primary, reflex, nature, but it secondarily promotes the peroxidation activation. The radiotoxins (of the quinoid and lipid nature) appearing in tissues under the effect of ionizing radiation, are similar in structure and mechanism of action to peroxidation activation products formed under the effect of other stress-agents.

[Comparative study of chemiluminescence and resistance of serum and its components after radiation exposure]

Kinetics of spontaneous chemiluminescence (CL) and electrochemiluminescence (ECL) and resistance of blood serum and its protein, lipid and carbohydrate components under the effect of X-rays (3 to 1622 Gy) and the indirect effect of radiation initiated by the addition of hydrogen peroxide (1.5 X 10(-5)-1.5%) was studied to estimate the contribution of each of the serum components to cumulative changes in the kinetics of free radical oxidation initiated by the effect of radiation. There was a parametric dependence between the absorbed dose, the rate of ECL and the resistance of blood serum and its components. As the absorbed dose or hydrogen peroxide concentration increased ECL contribution to the cumulative luminescence signal regularly decreased. Changes in CL and ECL of blood serum induced by ionizing radiation and H2O2 were qualitatively similar. The kinetics of free radical oxidation of blood serum initiated by irradiation was determined integrally (according to CL and ECL parameters) by a complex of changes in its components.

[Inhibition of the endocrine function of the rat thymus by x-irradiation]

Whole-body X-irradiation of rats caused inhibition of endocrine function of thymus. The effect was a function of radiation dose and time after irradiation. 72 h following irradiation with doses of 6 and 8 Gy the thymus hormone content of blood serum fell down the level registered in the thymectomized animals. Cellularity of the thymus and spleen concurrently decreased. The kinetics of spontaneous chemiluminescence of blood serum, thymus and spleen cells characterized the hypersecretion of glucocorticoids in response to radiation activation of lipid peroxidation in radiosensitive rat organs.

[Effect of extreme factors and adaptation to high-altitude conditions on peroxidation indices of serum lipids]

High and low temperatures, physical exercises and acute hypoxia are studied for their effect on indices of peroxide lipid oxidation in highly trained persons under alpine conditions (2100-5600 m). Temperature effects (-15 degrees C and +100 degrees C, for 30 minutes) as well as their combination with acute hypoxy cause an increase (by 10-30%) of malonic dialdehyde and a decrease (by 46-70%) of spontaneous chemoluminescence of blood serum in nonadapted people. Adaptation to alpine conditions in combination with physical exercises and low-caloric diet decreases shifts of these indices, considerably increasing the organism stability to the action of such extreme stress agents as high and low temperatures and acute hypoxy.

[Radiosensitivity of thymocytes and bone marrow cells of the lymphoid series based on data from a study of the kinetics of spontaneous chemiluminescence]

Two peaks of spontaneous chemiluminescence (SHL), registered at a time of mass cell death (minutes 5 and 55), were detected in a suspension of intact thymocytes during a complement-depending cytotoxic test (CDCT) with anti-theta-serum. The second peak disappeared in suspensions irradiated with doses of 4, 6, 8 and 10 Gy; as the dose increased the first peak appeared at earlier times after irradiation (1-2 min), and cells died more rapidly. As to intact bone-marrow cells of a lymphoid series, a stimulatory effect of thymosin on the theta-antigen expression was detected during CDCT with a reference to the increased quantum yield of SCL. After irradiation of the suspension (6 and 8 Gy) cells died more rapidly and SCL peak appeared earlier. When CDCT was conducted 15 min after irradiation of rats (6 Gy) incubation with thymosin influenced the appearance of the peak at earlier times after irradiation.