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1.
Stomatologiia (Mosk) ; 81(4): 54-6, 2002.
Article in Russian | MEDLINE | ID: mdl-12380300

ABSTRACT

Mean doses of ionizing radiation, absorbed by children in the Byelarus Republic, were evaluated by EPR dosimetry of tableted samples of milk teeth enamel. A relationship between the doses absorbed by the children and density of radionuclide contamination of the territory of residence was detected. Based on the mean absorbed doses, doses which can be absorbed during 70 years of life were estimated.


Subject(s)
Dental Enamel/radiation effects , Radioactive Hazard Release , Radioactive Pollutants/adverse effects , Tooth, Deciduous/radiation effects , Absorption , Adolescent , Child , Dental Enamel/metabolism , Dose-Response Relationship, Radiation , Humans , Radiation, Ionizing , Radiometry , Republic of Belarus
2.
Radiats Biol Radioecol ; 40(2): 154-9, 2000.
Article in Russian | MEDLINE | ID: mdl-10819037

ABSTRACT

The fluorescence probe method was used for investigating the physical state of a total lipid phase of a bi-layer and an annular (near-protein) zone of the membrane lipids of lymphocytes in a peripheral blood of rats on the 10th day after a whole-body acute and chronic gamma-exposure to doses of 0.25, 0.5, and 1.0 Gy. It was discovered that exposure to doses of 0.25, 0.5, and 1.0 Gy revealed no reliable distinctions in the parameters of a physical state of the lipid component of membranes within the given period of observation if compared with those of controls. However chronic exposure to the same doses caused the increase in hydrophobicity of the total lipid phase of the membrane bi-layer with no change in the polarity of an annular lipid. The near-protein zone of lipids revealed a local decrease in microviscosity while the fluidity of total lipids of a membrane bi-layer remained unaltered. A detected change of tryptophan fluorescence of the membrane proteins after exposing them to small dosed has also been carried out.


Subject(s)
Cell Membrane/radiation effects , Lymphocytes/radiation effects , Lymphocytes/ultrastructure , Membrane Lipids/radiation effects , Animals , Cell Membrane/chemistry , Dose-Response Relationship, Radiation , Gamma Rays , Lymphocytes/chemistry , Male , Membrane Fluidity/radiation effects , Membrane Lipids/chemistry , Rats , Whole-Body Irradiation
4.
Stomatologiia (Mosk) ; 78(2): 12-4, 1999.
Article in Russian | MEDLINE | ID: mdl-10224900

ABSTRACT

Salivary specimens of 80 children aged 8-14 years from the Stolin District and of 34 children of the city of Minsk are examined by radial immunodiffusion in gel and by enzyme immunoassay. Residents of a region contaminated with radionuclides (soil contamination with 137Cs 185-555 kBq/m2) develop an imbalance in the production and secretion of specific salivary antibodies: the production of IgM in early periods of immune response is suppressed and the level of IgE is increased.


Subject(s)
Ecology , Environmental Exposure/analysis , Immunoglobulins/analysis , Saliva/chemistry , Soil Pollutants, Radioactive/adverse effects , Adolescent , Analysis of Variance , Binomial Distribution , Child , Discriminant Analysis , Environmental Exposure/adverse effects , Environmental Exposure/statistics & numerical data , Humans , Immunodiffusion/statistics & numerical data , Immunoglobulins/radiation effects , Republic of Belarus , Saliva/radiation effects
5.
Radiats Biol Radioecol ; 34(4-5): 651-6, 1994.
Article in Russian | MEDLINE | ID: mdl-7951898

ABSTRACT

Incorporated 137Cs (absorbed dose of 0.26 Gy) causes decrease of myocardial's contractile function and inotropic response to beta-adrenagonists effect, isoproterenol-stimulated adenylate cyclase activity and beta-adrenoreceptors affinity. Adrenergic effects, mediated by alpha-adrenergic structures on heart contractile function, on the contrary, become stronger, that is due to the increase of the receptors' density on sarcolemma surface.


Subject(s)
Cesium Radioisotopes , Myocardial Contraction/radiation effects , Receptors, Adrenergic, alpha/radiation effects , Receptors, Adrenergic, beta/radiation effects , Adenylyl Cyclases/metabolism , Animals , Enzyme Activation/radiation effects , Myocardial Contraction/physiology , Myocardium/enzymology , Rats , Receptors, Adrenergic, alpha/physiology , Receptors, Adrenergic, beta/physiology , Time Factors
6.
Radiats Biol Radioecol ; 33(4): 521-4, 1993.
Article in Russian | MEDLINE | ID: mdl-8401872

ABSTRACT

Chronic gamma-irradiation (1 Gy, 100 mR/hr) increases cell titre in rat thymus and decreases glucose transport activation by phorbol ester. Animals kept in the Chernobyl evacuation zone over a period of 30 days exhibit reduced thymus cellularity and decreased PMA (200 nM) stimulation of glucose uptake by thymus cells.


Subject(s)
Accidents, Occupational , Environmental Exposure , Glucose/pharmacokinetics , Nuclear Reactors , Thymus Gland/radiation effects , Animals , Biological Transport/radiation effects , Male , Models, Biological , Phorbol Esters/pharmacology , Protein Kinase C/metabolism , Rats , Thymus Gland/cytology , Thymus Gland/metabolism , Time Factors
7.
Radiobiologiia ; 33(2): 302-6, 1993.
Article in Russian | MEDLINE | ID: mdl-8502752

ABSTRACT

The influence of incorporated cesium 137 (the absorbed doses of 0.26-0.08 Gy) on the erythrocyte membrane structure has been investigated. It has been shown that chronic internal exposure to gamma radiation causes structural reorganization of erythrocyte membranes at remote postirradiation times (in 3 and 6 months) that influences the annular membrane lipid.


Subject(s)
Cesium Radioisotopes/pharmacology , Erythrocyte Membrane/radiation effects , Animals , Cesium Radioisotopes/blood , Erythrocyte Membrane/metabolism , Erythrocyte Membrane/ultrastructure , Fluorescent Dyes , Gamma Rays , Male , Membrane Lipids/radiation effects , Osmotic Fragility/radiation effects , Rats , Time Factors
9.
Radiobiologiia ; 31(1): 48-51, 1991.
Article in Russian | MEDLINE | ID: mdl-1826176

ABSTRACT

A study was made of Ca2(+)-accumulating ability of plasma membranes of nonstriated cells of rat aorta 3, 10, 30, 180 and 365 days after whole-body gamma irradiation with doses of 0.5, 1.0 and 4.0 Gy. The radiation doses used were shown to cause structural and functional modification of Ca2(+) pump which was a function of dose. The process under study was normalized during the first months following irradiation.


Subject(s)
Calcium/radiation effects , Muscle, Smooth, Vascular/radiation effects , Whole-Body Irradiation , Animals , Aorta/metabolism , Aorta/radiation effects , Calcium/metabolism , Calcium-Transporting ATPases/metabolism , Calcium-Transporting ATPases/radiation effects , Cell Membrane/metabolism , Cell Membrane/radiation effects , Dose-Response Relationship, Radiation , Gamma Rays , Male , Muscle, Smooth, Vascular/metabolism , Rats , Rats, Inbred Strains , Time Factors
10.
Fiziol Zh (1978) ; 36(5): 36-42, 1990.
Article in Russian | MEDLINE | ID: mdl-2176989

ABSTRACT

Results of the authors' studies and data from literature underlie the development of a notion on structural rearrangement of the brain synaptic membranes in aging. Reorganization results in conformational changes of the key membrane-bound enzymes and receptors underlying the age alterations of neuronal functions.


Subject(s)
Aging/pathology , Brain/pathology , Synaptic Membranes/pathology , Animals , Brain/enzymology , Protein Conformation , Receptors, Neurotransmitter/ultrastructure , Synaptic Membranes/enzymology
11.
Radiobiologiia ; 30(1): 54-6, 1990.
Article in Russian | MEDLINE | ID: mdl-2156281

ABSTRACT

Using the fluorescent probe and membrane filtration methods it has been shown that 3 days after gamma-irradiation of rats with a dose of 1 Gy microviscosity of membranes increases and their Ca2(+)-transport function decreases with a simultaneous increase in the affinity of Ca2(+)-pump for calcium. In 15 days, the characteristics under study do not differ from those of the intact controls.


Subject(s)
Muscle, Smooth, Vascular/radiation effects , Animals , Calcium Channels/physiology , Calcium Channels/radiation effects , Calcium Channels/ultrastructure , Cell Membrane/physiology , Cell Membrane/radiation effects , Cell Membrane/ultrastructure , Dose-Response Relationship, Radiation , Gamma Rays , Male , Membrane Fluidity/physiology , Membrane Fluidity/radiation effects , Muscle, Smooth, Vascular/physiology , Muscle, Smooth, Vascular/ultrastructure , Rats , Rats, Inbred Strains , Time Factors , Viscosity
12.
Biull Eksp Biol Med ; 108(10): 433-5, 1989 Oct.
Article in Russian | MEDLINE | ID: mdl-2597755

ABSTRACT

The lipid fluidity in heart sarcoplasmic reticulum membranes prepared from adult (12 mo.) and old (24 mo.) rats has been measured by the fluorescence probe (DPPH) and spin probe (5NS) methods at 22 and 37 degrees C. The lipid fluidity in the old rat membranes is higher than that in the adult rat ones. It has been suggested that this difference is caused by age lowering in reliability of membrane fluidity stabilization systems.


Subject(s)
Lipid Metabolism , Myocardium/metabolism , Sarcoplasmic Reticulum/metabolism , Age Factors , Animals , Cyclic N-Oxides , Diphenylhexatriene , Fluorescent Dyes , Male , Rats , Rats, Inbred Strains , Spin Labels
13.
Biofizika ; 32(3): 438-42, 1987.
Article in Russian | MEDLINE | ID: mdl-3040128

ABSTRACT

Cardiomyocyte plasmalemma membranes of adult (12 months) and old (24-26 months) rats have been studied. Ageing is accompanied with an essential decrease of the content of the membrane protein SH-groups. We have found an increase in the fraction of strongly immobilized spin-labeled SH-groups, a decrease in that of unsaturated lipids, as well as an increase in that of lysophosphatidylcholine in old rats membranes. The pattern of the response of beta-adrenergic receptors to isoproterenol is changed with age. The mobility of spin probe 5NS in the membranes of old rats is lowered at 22.5 degrees C. However there is no statistically significant age difference in the spin-probe mobility at 37 degrees C. Possible role of lysophosphatidylcholine in the stabilization of membrane lipid "fluidity" at physiological temperatures is suggested.


Subject(s)
Aging/metabolism , Myocardium/metabolism , Sarcolemma/metabolism , Animals , Cell Membrane/metabolism , Electron Spin Resonance Spectroscopy , Fatty Acids/metabolism , Male , Membrane Lipids/metabolism , Membrane Proteins/metabolism , Phospholipids/metabolism , Rats , Rats, Inbred Strains , Sulfhydryl Compounds/metabolism
14.
Biofizika ; 29(4): 640-2, 1984.
Article in Russian | MEDLINE | ID: mdl-6091786

ABSTRACT

Below 37 degrees the mobility of lipids in rat brain synaptic membranes evaluated by the spin probe method is higher in old (24-26 months) than in young (5-6 months) animals. The number of ouabain receptors in membranes increases with age, while maximum rate and Km values are not changed. The relation between structural state of membrane and properties of ouabain binding centers is discussed.


Subject(s)
Aging , Brain/metabolism , Synaptic Membranes/metabolism , Animals , Binding Sites , Brain/enzymology , Cell Membrane/metabolism , Lipid Bilayers/metabolism , Rats , Receptors, Drug/metabolism , Sodium-Potassium-Exchanging ATPase/metabolism , Spin Labels , Synaptic Membranes/enzymology , Temperature
15.
Biofizika ; 28(4): 709-11, 1983.
Article in Russian | MEDLINE | ID: mdl-6615913

ABSTRACT

In old rats in contrast to young and mature ones the treatment of synaptic membranes with SH-reagent N-ethylmaleimide, cholinergic agonist carbamylcholine or both of them decreases the specific binding of labeled muscarinic antagonist 3H-quinuclidinylbenzylate. The age related change of receptor conformation with exposure of thiol groups responsible for antagonist binding is suggested.


Subject(s)
Brain/growth & development , Receptors, Muscarinic/metabolism , Synaptic Membranes/metabolism , Aging , Animals , Brain/metabolism , Ethylmaleimide/pharmacology , Kinetics , Quinuclidinyl Benzilate/metabolism , Rats
16.
Biofizika ; 27(4): 650-2, 1982.
Article in Russian | MEDLINE | ID: mdl-6289920

ABSTRACT

In the brain synaptic membranes from old rats (24-26 months) in comparison with the mature ones (6-7 months) an increase was shown in disintegration rate with DDS Na, mobility of 5-, 16-doxyl-stearate spin probes and in thermosensitivity of acetylcholinesterase. The total number of SH-groups decreased. While protein composition remained constant lysophosphatidylcholine and saturated fatty acid content in old animals increased. The age-dependent structural rearrangement of synaptic membranes is suggested.


Subject(s)
Brain/growth & development , Synaptic Membranes/physiology , Aging , Animals , Electron Spin Resonance Spectroscopy , Rats , Sodium Dodecyl Sulfate , Temperature
17.
Biofizika ; 27(1): 156-8, 1982.
Article in Russian | MEDLINE | ID: mdl-6279169

ABSTRACT

Affinity of beta-adrenoreceptors in the rat brain synaptic membranes to agonists isoproterenol and norepinephrine, as well as to antagonist 125I-hydroxybenzylpindolol is lower in young (1 month) and old (24--26 months) than in mature (8--12 months) rats. Desensitization toward isoproterenol is expressed in the young ones only. In the old but not in other groups simultaneous action of isoproterenol and N-ethylmaleimide decreases the following binding of the antagonist while the same agents added separately produced no effect. It is suggested that beta-adrenoreceptors undergo age-related changes in their conformational state due to modification of the membrane environment.


Subject(s)
Brain/growth & development , Receptors, Adrenergic, beta/metabolism , Receptors, Adrenergic/metabolism , Synaptic Membranes/metabolism , Aging , Animals , Benzyl Alcohols/metabolism , Brain/metabolism , Isoproterenol/metabolism , Norepinephrine/metabolism , Pindolol/analogs & derivatives , Pindolol/metabolism , Rats , Substrate Specificity
18.
Biofizika ; 23(5): 821-6, 1978.
Article in Russian | MEDLINE | ID: mdl-698253

ABSTRACT

Studies are presented of the effect of procaine group anesthetics on rat brain synaptosome stability to dodecyl sulfate and on catalytic properties of the membrane bound alkaline phosphatase. The dose curves of detergent stability are characterized by two maxima, one at 3.10(-4) M for tetracaine, 2.10(-6) M for lidocaine and 5.10(-5) M for procaine; the other being at 10(-3) M for all anesthetics. The curves of Vmax and KM versus procaine concentration to exhibit the minimum at 5.10(-7) M and maximum at 3,2.10(-6) M. Procaine at 5.10(-7) M increases enthalpy and enthropy of membraneous alkaline phosphatase. It is suggested that interactions between anesthetics and centers of high affinity lead to synaptosome structural rearrangements, which affect the properties of membraneous enzymes.


Subject(s)
Alkaline Phosphatase , Brain/ultrastructure , Lidocaine/pharmacology , Procaine/pharmacology , Synaptosomes/drug effects , Tetracaine/pharmacology , Animals , Catalysis , Dose-Response Relationship, Drug , In Vitro Techniques , Rats , Sodium Dodecyl Sulfate , Synaptosomes/enzymology , Thermodynamics
20.
Biofizika ; 21(6): 1120-2, 1976 Nov.
Article in Russian | MEDLINE | ID: mdl-1009209

ABSTRACT

d-tubocurarine and procaine have been shown to inhibit the acetylcholinesterase of rat brain homogenate by coupled and non-competitive mechanism respectively, which suggests binding to enzyme peripheral sites. Judging by values of Hill coefficient negative cooperativity in interactions between procaine sites is characteristic of all ages (n=0,8 and 0,53 for young and old rats) while such cooperativity for d-tubocurarine sites appears only at old age (n=1 and 0,6 for young and old animals). Values of Ki changed in opposite directions for each of the substances with aging. Modification of the enzyme membrane microenvironment with aging was suggested as a reason for differences in enzyme allosteric behaviour.


Subject(s)
Aging , Brain/enzymology , Cholinesterase Inhibitors , Procaine/pharmacology , Tubocurarine/pharmacology , Animals , In Vitro Techniques , Rats
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