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1.
Biofizika ; 59(5): 862-70, 2014.
Article in Russian | MEDLINE | ID: mdl-25730966

ABSTRACT

The influence of biologically relevant anions (succinate, acetate, citrate, chloride, bicarbonate, hydroorthophosphate, dihydroorthophosphate, nitrite, nitrate) on the formation of hydrogen peroxide and hydroxyl radicals in water was studied under the effect of non-ionizing radiation: heat, laser light with a wavelength of 632.8 nm, corresponding to the maximum absorption of molecular oxygen, and electromagnetic radiation of extremely high frequencies. It has been established that various anions may both inhibit the formation of reactive oxygen species and increase it. Bicarbonate and sulfate anions included in the biological fluids' and medicinal mineral waters have significant, but opposite effects on reactive oxygen species production. Different molecular mechanisms of reactive oxygen species formation are considered under the action of the investigated physical factors involving these anions, which may influence the biological processes by signal-regulatory manner and provide a healing effect in physical therapy.


Subject(s)
Acids/chemistry , Hot Temperature , Light , Reactive Oxygen Species/chemistry , Water/chemistry , Anions/chemistry
2.
Biofizika ; 56(4): 688-95, 2011.
Article in Russian | MEDLINE | ID: mdl-21950072

ABSTRACT

Using the alkaline single cell gel electrophoresis technique (comet assay), changes in chromatin structure of peripheral blood leukocytes and peritoneal neutrophils have been studied in mice exposed to low-intensity extremely high-frequency electromagnetic radiation (42.2 GHz, 0.1 mW/cm2, 20 min at 1 h after induction of inflammation) against the background of the systemic inflammatory process. It was revealed that the exposure of mice with the developing inflammation leads to a pronounced decrease in the level of DNA damage to peripheral blood leukocytes and peritoneal neutrophils. It is supposed that the changes in the chromatin structure of lymphoid cells have a genoprotective character in the inflammatory process and can underlie the mechanisms of realization of antiinflammatory effects of the electromagnetic radiation.


Subject(s)
Chromatin/metabolism , Lymphocytes/metabolism , Microwaves , Peritonitis/metabolism , Animals , Inflammation/chemically induced , Inflammation/metabolism , Inflammation/therapy , Male , Mice , Mice, Inbred BALB C , Neutrophils/metabolism , Peritonitis/chemically induced , Peritonitis/therapy , Short-Wave Therapy
3.
Biofizika ; 55(4): 645-51, 2010.
Article in Russian | MEDLINE | ID: mdl-20968076

ABSTRACT

Changes in T cell subsets and expression of cytokine genes in thymocytes and splenocytes after exposure of BAL/c mice to low-intensity extremely high-frequency electromagnetic radiation (42.2 GHz, 0.1 mW/cm2, exposure duration 20 min) under normal conditions and in systemic inflammation were studied using flow cytometry and the methods of reverse transcription and real-time polymerase chain reaction. It was found that the number of CD4+ and CD8+ T cells statistically significantly increased in the thymus and considerably decreased in the spleen of exposed animals. Apparently, the exposure of animals leads to an intensification of the host defense, by activating the T-cellular immunity. As for effector functions, the increased expression of IL-1beta and IFNgamma genes in thymocytes and essentially enhanced expression of IL-1beta, IL-10, and TNFalpha genes in splenocytes were observed in mice exposed against the background of a progressive inflammatory process. The experimental data obtained specify that the directed (anti-inflammatory) response of an organism to a specific combination of effective exposure parameters of electromagnetic radiation can be realized by the activation of particular immunocompetent cells and changes in the cytokine profile.


Subject(s)
Lymphocytes/radiation effects , Microwaves , Spleen/radiation effects , Systemic Inflammatory Response Syndrome/pathology , Animals , Cytokines/biosynthesis , Lymphocytes/cytology , Lymphocytes/metabolism , Male , Mice , Mice, Inbred BALB C , Spleen/cytology , Spleen/metabolism , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/metabolism , T-Lymphocytes/radiation effects
4.
Biofizika ; 54(6): 1128-36, 2009.
Article in Russian | MEDLINE | ID: mdl-20067195

ABSTRACT

The influence of different exposure regimes of low-intensity extremely high-frequency electromagnetic radiation on the growth rate of solid Ehrlich carcinoma in mice has been studied. It was shown that, at an optimum repetition factor of exposure (20 min daily for five consecutive days after the tumor inoculation), there is a clearly pronounced frequency dependence of the antitumor effect. The analysis of experimental data indicates that the mechanisms of antitumor effects of the radiation may be related to the modification of the immune status of the organism. The results obtained show that extremely high-frequency electromagnetic radiation at a proper selection of exposure regimes can result in distinct and stable antitumor effects.


Subject(s)
Carcinoma, Ehrlich Tumor/radiotherapy , Microwaves/therapeutic use , Animals , Carcinoma, Ehrlich Tumor/pathology , Male , Mice , Neoplasm Transplantation
5.
Biofizika ; 52(5): 947-52, 2007.
Article in Russian | MEDLINE | ID: mdl-17969932

ABSTRACT

A pronounced anti-inflammatory effect of high peak-power pulsed electromagnetic radiation of extremely high frequency was shown for the first time in a model of zymosan-induced footpad edema in mice. Exposure to radiation of specific parameters (35, 27 GHz, peak power 20 kW, pulse widths 400-600 ns, pulse repetition frequency 5-500 Hz) decreased the exudative edema and local hyperthermia by 20% compared to the control. The kinetics and the magnitude of the anti-inflammatory effect were comparable with those induced by sodium diclofenac at a dose of 3 mg/kg. It was found that the anti-inflammatory effect linearly increased with increasing pulse width at a fixed pulse repetition frequency and had threshold dependence on the average incident power density of the radiation at a fixed pulse width. When animals were whole-body exposed in the far-field zone of radiator, the optimal exposure duration was 20 min. Increasing the average incident power density upon local exposure of the inflamed paw accelerated both the development of the anti-inflammatory effect and the reactivation time. The results obtained will undoubtedly be of great importance in the hygienic standardization of pulsed electromagnetic radiation and in further studies of the mechanisms of its biological action.


Subject(s)
Edema/radiotherapy , Fever/radiotherapy , Radiation , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Diclofenac/pharmacology , Dose-Response Relationship, Radiation , Edema/chemically induced , Fever/chemically induced , Inflammation/chemically induced , Inflammation/radiotherapy , Male , Mice , Zymosan/toxicity
6.
Biofizika ; 52(6): 1087-92, 2007.
Article in Russian | MEDLINE | ID: mdl-18225661

ABSTRACT

The capability of high peak-power pulsed electromagnetic radiation of extremely high frequency (35,27 GHz, pulse widths of 100 and 600 ns, peak power of 20 kW) to excite acoustic waves in model water-containing objects and muscular tissue of animals has been experimentally shown for the first time. The amplitude and duration of excited acoustic pulses are within the limits of accuracy of theoretical assessments and have a complex nonlinear dependence on the energy input of electromagnetic radiation supplied. The velocity of propagation of acoustic pulses in water-containing models and isolated muscular tissue of animals was close to the reference data. The excitation of acoustic waves in biological systems under the action of high peak-power pulsed electromagnetic radiation of extremely high frequency is the important phenomenon, which essentially contributes to the understanding of the mechanisms of biological effects of these electromagnetic fields.


Subject(s)
Acoustics , Microwaves , Models, Biological , Water/chemistry , Gelatin/chemistry
7.
Biofizika ; 51(6): 1055-68, 2006.
Article in Russian | MEDLINE | ID: mdl-17175917

ABSTRACT

The anti-inflammatory effect of low-intensity extremely high-frequency electromagnetic radiation (EHF EMR, 42.0 GHz, 0.1 mW/cm2) was compared with the action of the known anti-inflammatory drug sodium diclofenac and the antihistamine clemastine on acute inflammatory reaction in NMRI mice. The local inflammatory reaction was induced by intraplantar injection of zymosan into the left hind paw. Sodium diclofenac in doses of 2, 3, 5, 10, and 20 mg/kg or clemastine in doses of 0.02, 0.1, 0.2, 0.4, and 0.6 mg/kg were injected intraperitoneally 30 min after the initiation of inflammation. The animals were whole-body exposed to EHF EMR for 20 min at 1 h after the initiation of inflammation. The inflammatory reaction was assessed over 3 - 8 h after the initiation by measuring the footpad edema and hyperthermia of the inflamed paw. Sodium diclofenac in doses of 5 - 20 mg/kg reduced the exudative edema on the average by 26% as compared to the control. Hyperthermia of the inflamed paw decreased to 60% as the dose of was increased diclofenac up to 20 mg/kg. EHF EMR reduced both the footpad edema and hyperthermia by about 20%, which was comparable with the effect of a single therapeutic dose of diclofenac (3 - 5 mg/kg). The combined action of diclofenac and the exposure to the EHF EMR caused a partial additive effect. Clemastine in doses of 0.02-0.4 mg/kg it did not cause any significant effects on the exudative edema, but in a dose of 0.6 mg/kg it reduced edema by 14 - 22% by 5 - 8 h after zymosan injection. Clemastine caused a dose-dependent increase in hyperthermia of inflamed paw at doses of 0.02-0.2 mg/kg and did not affect the hyperthermia at doses of 0.4 and 0.6 mg/kg. The combined action of clemastine and EHF EMR exposure caused a dose-dependent abolishment of the anti-inflammatory effect of EHF EMR. The results obtained suggest that both arachidonic acid metabolites and histamine are involved in the realization of anti-inflammatory effects of low-intensity


Subject(s)
Inflammation/radiotherapy , Microwaves/therapeutic use , Animals , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Clemastine/therapeutic use , Diclofenac/therapeutic use , Inflammation/chemically induced , Inflammation/drug therapy , Male , Mice , Mice, Inbred Strains
8.
Radiats Biol Radioecol ; 46(6): 713-8, 2006.
Article in Russian | MEDLINE | ID: mdl-17323700

ABSTRACT

The radioprotective effects of guanosine and of inosine on bone marrow cells of mice exposed to acute X-rays (1.5 Gy) were studied by using the micronuclear test. The guanosine and inosine (riboxine) decrease the frequency of micronucleated polychromatic erythrocytes and significantly recover erythropoiesis. Also, radioprotective effects of the guanosine and of the inosine on the irradiated leucocytes of mice were tested by the alkaline comet assay. Was shown that purine ribonucleosides diminish quantity of DNA damage and activates repair processes in leucocytes under irradiation of blood and animals. The reactive oxygen species induced by ionizing radiation perform essential role in DNA damaging. Using a sensitive method of enhanced chemiluminescence in a peroxidase-luminol-p-iodophenol system for quantitative measurement of hydrogen peroxide and coumarin-3-carboxylic acid for quantitative measurement of hydroxyl radicals we have shown that guanosine and inosine essentially decrease the yield of hydrogen peroxide and hydroxyl radicals in X-ray-irradiated water. The results obtained indicate that radioprotective properties of guanosine and inosine (riboxine) in the blood cells are operative at the genome level.


Subject(s)
Blood Cells/radiation effects , Guanosine/physiology , Inosine/physiology , Radiation-Protective Agents/pharmacology , Animals , Blood Cells/drug effects , Comet Assay , DNA Damage/drug effects , Dose-Response Relationship, Radiation , Guanosine/pharmacology , Hydrogen Peroxide/metabolism , Hydroxyl Radical/analysis , Hydroxyl Radical/metabolism , Inosine/pharmacology , Leukocytes/drug effects , Leukocytes/radiation effects , Luminescence , Mice , Mice, Inbred Strains , Micronucleus Tests , Water , Whole-Body Irradiation , X-Rays
9.
Biofizika ; 50(5): 773-9, 2005.
Article in Russian | MEDLINE | ID: mdl-16248149

ABSTRACT

Using the method of enhanced chemiluminescence in a peroxidase-luminol-p-iodophenol system, we found the formation of reactive oxygen species (in equivalent of hydrogen peroxide concentration) in 1 mM phosphate buffer under the exposure to high peak-power pulsed electromagnetic radiation of extremely high frequencies (37 GHz, peak power 20 kW, pulse width 400 ns, repetition rate 500 Hz). The results obtained show that the formation of hydrogen peroxide in aqueous solutions under the action of electromagnetic radiation is the result of the summary influence of heat and thermoacoustic waves excited in the solutions.


Subject(s)
Electromagnetic Fields , Hydrogen Peroxide/chemistry , Hydroxyl Radical/chemistry , Water/chemistry , Dose-Response Relationship, Radiation , Hot Temperature , Oxidation-Reduction
10.
Bull Exp Biol Med ; 137(4): 364-6, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15452603

ABSTRACT

Low-intensity ultrahigh frequency electromagnetic radiation (42 GHz, 100 microW/cm(2)) reduces the severity of inflammation and inhibits production of active oxygen forms by inflammatory exudate neutrophils only in mice with inflammatory process. These data suggest that some therapeutic effects of electromagnetic radiation can be explained by its antiinflammatory effect which is realized via modulation of functional activity of neutrophils in the focus of inflammation.


Subject(s)
Electromagnetic Fields , Inflammation , Microwaves , Animals , Inflammation/chemically induced , Male , Mice , Reactive Oxygen Species/metabolism , Whole-Body Irradiation , Zymosan/administration & dosage , Zymosan/immunology
11.
Radiats Biol Radioecol ; 43(1): 87-92, 2003.
Article in Russian | MEDLINE | ID: mdl-12677665

ABSTRACT

Using a comet assay technique, it was shown for the first time that low-intensity extremely high-frequency electromagnetic radiation (EHF EMR) in vivo causes oppositely directed effects on spatial organization of chromatin in cells of lymphoid organs. In 3 hrs after single whole-body exposure of NMRI mice for 20 min at 42.0 GHz and 0.15 mW/cm2, an increase by 16% (p < 0.03 as compared with control) and a decrease by 16% (p < 0.001) in fluorescence intensity of nucleoids stained with ethidium bromide were found in thymocytes and splenocytes, respectively. The fluorescence intensity of stained nucleoids in peripheral blood leukocytes was not changed after the exposure. The exposure of cells of Raji hunan lymphoid line and peripheral blood leukocytes to the EHF EMR in vitro induced a decrease in fluorescence intensity by 23% (p < 0.001) and 18% (p < 0.05), respectively. These effects can be determined by changes in a number of physiological alkali-labile sites in DNA of exposed cells. We suggested that the effects of low-intensity EHF EMR on the immune system cells are realized with the participation of neuroendocrine and central nervous systems.


Subject(s)
Chromatin/radiation effects , Electromagnetic Fields , Spleen/cytology , Spleen/radiation effects , T-Lymphocytes/radiation effects , Thymus Gland/radiation effects , Animals , Cells, Cultured , Comet Assay , DNA/radiation effects , Fluorescence , Humans , Leukocytes/radiation effects , Male , Mice , Radiation Dosage , Spleen/metabolism , Thymus Gland/metabolism , Time Factors
12.
Radiats Biol Radioecol ; 42(5): 533-45, 2002.
Article in Russian | MEDLINE | ID: mdl-12449822

ABSTRACT

Low-intensity of electromagnetic radiation of extremely high frequencies (EHF EMR) is effectively used in medical practice for diagnostics, prevention and treatment of a broad spectrum of diseases of different etiology. However, in spite of existence of many hypotheses about mechanisms of EHF EMR effects on the molecular and cellular levels of organization of living systems, there is not conception that could explain all diversity of the EHF-therapy effects from unified approach. In our opinion, the problem of determination of mechanisms of EHF EMR effects on living organism is divided into two basic tasks: first, determining subcellular structures which can receive radiation, and, second, studying physiological reactions of the organism which are caused by radiation. It is obviously, that investigation of functions of single cells and subcellular elements can not entirely explain therapeutic effects and mechanisms of EHF EMR influence on multicellular organism on the whole. Plenty of functional relationships between organs and systems of organs should be taken into account. In the present review, a realization of the EHF-therapy effects due to the influence on immune system functions and start of system mechanisms of maintenance of the homeostasis on the organism level is hypothesized. Potential targets for EHF EMR acception on the level of different systems of the organism are analysed. The material is formed so that functional relations between immune system and other regulatory systems (nervous and endocrine systems) are traced.


Subject(s)
Electromagnetic Fields , Homeostasis/radiation effects , Immune System/radiation effects , Adaptation, Physiological , Animals , Antigen-Antibody Complex/radiation effects , Catecholamines/blood , Cells, Cultured , Endocrine System/radiation effects , Gamma Rays , Humans , Mice , Mice, Inbred BALB C , Radiation Dosage , Rats , Skin/radiation effects , Spleen/radiation effects , Syndrome , T-Lymphocytes/immunology , T-Lymphocytes/radiation effects , Thymus Gland/radiation effects , Time Factors
13.
Biofizika ; 47(4): 759-68, 2002.
Article in Russian | MEDLINE | ID: mdl-12298218

ABSTRACT

Using experimental and theoretical methods of dosimetry, the energy absorption of extremely high-frequency electromagnetic radiation (EHF EMR) in the skin of laboratory rats was analyzed. Specific absorption rate (SAR) in the skin was determined on the basis of both microthermometric measurements of initial rates of temperature rise in rat skin induced by the exposure and microcalorimetric measurements of specific heat of the skin. Theoretical calculations of SAR in the skin were performed with consideration for dielectric parameters of rat skin obtained from the measurements of the standing wave ratio upon reflection of electromagnetic waves from the skin surface and for the effective area of stationary overheating measured by infrared thermography. A numerical method was developed to determine electromagnetic wave energy reflected, absorbed, and transmitted in the model of flat layers. The algorithm of the method was realized in a computer program and used to calculate SAR in the skin on the basis of the complex dielectric constant of rat skin. The SAR values obtained from experimental measurements, theoretical calculations and numerical analysis are in good mutual correspondence and make about 220-280 W/kg at a frequency of 42.25 GHz and a power of 20 mW at the radiator output. The results obtained can be used for dosimetric supply of biomedical experiments on studying the physicochemical mechanisms of the biological effects of EHF EMR.


Subject(s)
Electromagnetic Fields , Skin Physiological Phenomena/radiation effects , Skin/radiation effects , Animals , Electric Conductivity , Radiometry/methods , Rats , Rats, Wistar , Skin/chemistry , Temperature
14.
Biofizika ; 47(1): 71-7, 2002.
Article in Russian | MEDLINE | ID: mdl-11855293

ABSTRACT

The dynamics of leukocyte number and functional activity of peripheral blood neutrophils under whole-body exposure of healthy mice to low-intensity extremely-high-frequency electromagnetic radiation (EHF EMR, 42.0 GHz, 0.15 mW/cm2, 20 min daily) was studied. It was shown that the phagocytic activity of peripheral blood neutrophils was suppressed by about 50% (p < 0.01 as compared with the sham-exposed control) in 2-3 h after the single exposure to EHF EMR. The effect persisted for 1 day after the exposure, and then the phagocytic activity of neutrophils returned to the norm within 3 days. A significant modification of the leukocyte blood profile in mice exposed to EHF EMR for 5 days was observed after the cessation of exposures: the number of leukocytes increased by 44% (p < 0.05 as compared with sham-exposed animals), mostly due to an increase in the lymphocyte content. The supposition was made that EHF EMR effects can be mediated via the metabolic systems of arachidonic acid and the stimulation of adenylate cyclase activity, with subsequent increase in the intracellular cAMP level. The results indicated that the whole-body exposure of healthy mice to low-intensity EHF EMR has a profound effect on the indices of nonspecific immunity.


Subject(s)
Electromagnetic Fields , Animals , Dose-Response Relationship, Radiation , Hepatitis, Animal/pathology , Leukocytes/cytology , Leukocytes/radiation effects , Male , Mice
15.
Biofizika ; 46(4): 661-75, 2001.
Article in Russian | MEDLINE | ID: mdl-11558378

ABSTRACT

A theoretical analysis of the dependence of cell response to modulated electromagnetic fields on the parameters of modulating signals was performed on the basis of the model for calcium-dependent membrane-associated intracellular signaling systems. Expressed amplitude-frequency "windows" in the response of the nonlinear system to external influence were shown to depend on the effective time during which the amplitude of the influencing signal exceeded some threshold value, which is determined by the properties of the system. The presence of negative values in the influencing signal, i.e. the variations in the rate of some process around the inherent value, played an important role for the effect characteristics. The response of the nonlinear system to external influence strongly depended on the waveform of the modulating signal which is determined not only by frequency spectrum, but also by the initial phase of each frequency component. To ensure a regime for the optimal effect, the rates of increase and drop in the modulating signal amplitude should be synchronized with dynamic processes in the biological object being exposed.


Subject(s)
Electromagnetic Fields , Signal Transduction , Algorithms , Calcium Signaling , Cell Membrane , Models, Biological , Nonlinear Dynamics
16.
Biofizika ; 46(4): 753-60, 2001.
Article in Russian | MEDLINE | ID: mdl-11558390

ABSTRACT

The modification of indices of the humoral immune response to thymus-dependent antigen (sheep erythrocytes) after a whole-body exposure of healthy mice to low-intensity extremely-high-frequency electromagnetic radiation was studied. Male NMRI mice were exposed in the far-field zone of horn antenna at a frequency of 42.0 GHz and energy flux density of 0.15 mW/cm2 under different regimes: once for 20 min, for 20 min daily during 5 and 20 successive days before immunization, and for 20 min daily during 5 successive days after immunization throughout the development of the humoral immune response. The intensity of the humoral immune response was estimated on day 5 after immunization by the number of antibody-forming cells of the spleen and antibody titers. Changes in cellularity of the spleen, thymus and red bone marrow were also assessed. The indices of humoral immunity and cellularity of lymphoid organs changed insignificantly after acute exposure and series of 5 exposures before and after immunization of the animals. However, after repeated exposures for 20 days before immunization, a statistically significant reduction of thymic cellularity by 17.5% (p < 0.05) and a decrease in cellularity of the spleen by 14.5% (p < 0.05) were revealed. The results show that low-intensity extremely-high-frequency electromagnetic radiation with the frequency and energy flux density used does not influence the humoral immune response intensity in healthy mice but influences immunogenesis under multiple repeated exposures.


Subject(s)
Antibody Formation/radiation effects , Microwaves , Animals , Antibody-Producing Cells , Bone Marrow/immunology , Cell Count , Electromagnetic Fields , Male , Mice , Spleen/immunology , Thymus Gland/immunology
17.
Biofizika ; 46(6): 1096-102, 2001.
Article in Russian | MEDLINE | ID: mdl-11771285

ABSTRACT

It was shown by light and electron microscopy that local exposure of the projection of the MC-8 lao-gun acupuncture point in rat pad to low-intensity (0.05 mW/cm2) extremely high-frequency (42.0 GHz) electromagnetic radiation caused a degranulation of derma mast cells. It was suggested that the response of skin mast cells is an important amplifying mechanism in the chain of events leading to a systemic response of the organism to low-intensity electromagnetic radiation.


Subject(s)
Cell Degranulation , Mast Cells/radiation effects , Microwaves , Skin/cytology , Animals , Male , Mast Cells/physiology , Mast Cells/ultrastructure , Microscopy, Electron , Rats , Rats, Wistar , Skin/ultrastructure
18.
Biofizika ; 45(2): 299-312, 2000.
Article in Russian | MEDLINE | ID: mdl-10776544

ABSTRACT

Frequency-dependent modifications of intracellular free calcium concentration ([Ca2+]i) in neutrophils exposures to modulated extremely high frequency electromagnetic radiation were analyzed using a special mathematical model for [Ca2+]i oscillations. The model took into account the activation of Ca2+ influx into the cell by cytosolic Ca2+ and Ca(2+)-induced Ca2+ release from intracellular stores. The calcium channels of plasma membrane were chosen as a target for the influence of harmonic signal and additive noise in the model. The model simulation showed that in response to modulating signal, the rise in [Ca2+]i, has frequency dependence and phase dependence in relation to the moment of chemical stimulation. The phase-frequency dependence of the effect was observed at a certain sequence of delivery of chemical stimulus and modulating signal to the cell. At intensities of modulating signals exceeding the threshold, a rise in [Ca2+]i, reaching a level of more than 50% of the initial level, was observed at a frequency of about 1 Hz and in the phase range of 0.3-2.5 radians. The effect was found only at high intensities of chemical stimulus. The additive noise introduced into the system modified qualitatively and quantitatively the phase-frequency characteristics of the cell response to the modulating signal. An increase in noise intensity resulted in a displacement of the average frequency of the band of rise in [Ca2+]i, and then the emergence of a set of bands with a greater Q-factors. The analysis of dynamics of the nonlinear system in terms of the stability theory showed that, as the intensity of chemical stimulus increases, the system transits by means of a series of bifurcations from regular driving to chaotic, and then to oscillations, induced by a modulating harmonic signal. The boundary of the transition of oscillations from chaotic to induced ones corresponds to a specific "threshold" of the intensity of chemical stimulus for the significant rise in [Ca2+]i in response to the modulating signal. The results of the model analysis are in good correspondence with the experimental data obtained earlier, namely, with the effects of modulated extremely high-frequency electromagnetic radiation on neutrophils, which were observed only in the presence of Ca2+ in extracellular medium and at high concentrations of calcium ionophore A23187. Thus, as the characteristic frequency of the quasi-periodic process of calcium signalling in the cell coincides with the frequency of external field, a narrow-band rise in [Ca2+]i is observed, which can result in a modification of the functional activity of the cell.


Subject(s)
Microwaves , Neutrophils/radiation effects , Animals , Calcium/metabolism , Calcium Channels/metabolism , Cell Membrane/metabolism , Cell Membrane/radiation effects , Models, Biological , Neutrophils/metabolism , Neutrophils/ultrastructure
20.
Biofizika ; 42(5): 1097-105, 1997.
Article in Russian | MEDLINE | ID: mdl-9410037

ABSTRACT

Direct and modulate effects of platelet activating factor (PAF), its structural analogues and ATP on primary and second processes at peritoneal neutrophils and P388D1 cells activation has been studied. The effect of compounds was evaluated on changes in Ca2+ transport and generation of reactive oxygen species. It was shown, that the synthetic analogues of MS series interact with PAF receptor, mobilize Ca2+ from thapsigargin-dependent intracellular stores and inhibit Ca2+ response on PAF in both types of cells. Unlike PAF the analogues do not induce the formations of reactive oxygen species in neutrophils and inhibit the PMA-induced respiratory burst. The activation of pyrinoreceptor of P388D1 cells by exogenous ATP does not inhibit PAF induced Ca2+ rise in cytoplasm, though partly releases Ca2+ from the same store.


Subject(s)
Leukemia P388/metabolism , Macrophages, Peritoneal/drug effects , Neutrophils/drug effects , Platelet Activating Factor/pharmacology , Signal Transduction , Adenosine Triphosphate/pharmacology , Animals , Calcium/metabolism , Luminescent Measurements , Macrophages, Peritoneal/metabolism , Mice , Neutrophils/metabolism , Peritoneal Cavity/cytology , Platelet Activating Factor/analogs & derivatives , Reactive Oxygen Species/metabolism , Respiratory Burst/drug effects , Tetradecanoylphorbol Acetate/pharmacology , Tumor Cells, Cultured
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