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Biomedical subjects

A V Putvinskiĭ

Publications and source records attributed to A V Putvinskiĭ.

16 recordsLinked to original sources
PubMed1987

[Induction of chemiluminescence of peritoneal exudate macrophages after exposure to an electric field].

The effect of the external high voltage electric field pulses on the suspension of rat peritoneal phagocytes has been investigated using chemiluminescent and turbodimetric methods. Single electric field pulses were found to activate macrophages, which was accompanied by a "flash" of chemiluminescence. Subthreshold electric field strength up to 0.8 kV/cm failed to alter macrophage activity. Maximum activation was observed at 2.2 kV/cm; with higher electric field intensity the effect diminished to zero. Drastic changes in light-scattering suspension properties at high electric field intensity indicate irreversible alterations of the barrier function of phagocyte membranes.

Animals↗
PubMedDate not supplied

[Proton permeability and electric breakdown of phospholipid membranes after UV-irradiation].

Lipid peroxidation induced in bilayer lipid membranes (BLM) by UV-irradiation leads to two types of effects: selective in proton permeability and electric breakdown of the membranes. Both phenomena are always observed but the contribution of each in the membrane conductivity increase depends on the lipid nature (degree of unsaturation of fatty acids) and the value of transmembrane applied to BLM or generated by the membrane itself.

Kinetics↗
PubMedDate not supplied

[The effect of continuous millimeter low-intensity radiation on the Na+ ion transport in the frog skin].

Many data on the effect of millimeter (MM) radiation of low intensity (of the order of 1 mVt/cm2) on living organisms were accumulated [1]. The specifics of this effect is first of all manifested in frequency--selective (resonance) pattern of the biological system response and the effect of threshold dependence of exposition time and power of MM radiation. To study the mechanism of this effect it seems perspective to investigate the influence of radiation on the membrane transport. The present work investigated the effect of MM radiation on a comparatively simple and well investigated object--isolated frog skin.

Animals↗
PubMedDate not supplied

[Electric stability of liposome membranes in UV-induced lipid peroxidation].

It has been shown that UV-induced peroxide oxidation of lipids (POL) and its water-soluble products similarly affect the liposomes of egg lecithin and mitochondrial lipids; they decrease the electric stability of the membranes, and aggregation ability of vesicles and increase proton permeability of the membranes. Possible mechanism of the increase of membrane ionic permeability during POL is discussed.

Animals↗
PubMedDate not supplied

[Electrical breakdown of erythrocyte membranes attributed to the diffusion potential difference].

A potential difference of a certain value can be obtained on the erythrocyte membranes if the cells are suspended in isotonic solution of low Cl- concentration. The potential value may be estimated by the pH changes in the medium without buffer. When the chloride membrane potential is high enough the electric breakdown, i.e. a sharp increase i of membrane ionic permeability, is observed.

Animals↗
PubMedDate not supplied

[Mechanism of human blood neutrophil activation by electric field pulses].

High voltage electric field pulses, was shown previously, induced activation of blood neutrophil respiratory burst, registered as increase in luminol-dependent chemiluminescence of cell suspension. The quantitative analysis of this phenomenon by fluorescent probes and radioisotope methods have shown that electric pulse induced neutrophil chemiluminescence is a result of Ca2+ ions entering the cells through reversible pores in plasma membrane. Electric pulse of amplitude 5 kV/cm generates two tens of reversible pores with average diameter nearly 2 nm and lifetime 1 minute. Total amount of calcium penetrating at this conditions from the medium (1 mM Ca2+) into the cells was as high as 1.2 fmole/cell that is nearly 3.6 mM concentration per cell volume. Whereas the increase in the cytoplasmic concentration of free calcium did not exceed 1.3 microM, that is more then 3 order less. Data presented is discussed with relation to possible biological role of electroporation by natural electric fields presented in living systems.

Calcium↗
PubMedDate not supplied

[Decrease in the electrical stability of lipid membranes following UV-irradiation].

The influence of UV-irradiation on the electrical stability of black lipid membranes (BLM) prepared from mitochondrial lipids has been studied. The breakdown voltage of BLM is shown to decrease as a result of photoperoxidation of unsaturated fatty acid chains of phospholipids. It appears reasonable to assume that the UV-radiation induces the dielectric breakdown and alteration of functions of cell membranes (i.e. UV-uncoupling of oxidative phorylation in mitochondria).

Electrochemistry↗