Zeta potential response of human erythrocyte membranes to the modulators of Gardos channel activity under low rate β-radiation

OBJECTIVE

Study of human erythrocyte DP response under modification by activators and blockers of the functional state of Ca2+-dependent K+ channels under low rate β-radiation.

MATERIALS AND METHODS

Erythrocytes were isolated from the donor blood. The zeta potential was computed from the value of the cell electrophoretic mobility. The investigated drugs preliminary introduced in cellular suspensions, and then aliquote of 90Sr(NO3)2 solution to get the final activity concentration of 44,4kBq⋅l-1.

RESULTS

The radioisotope radiation of 90Sr/90Y (RR, 15 μGy⋅h-1) increases an absolute value of erythrocyte membranes DP (DPab), and its action is reversible. It specifies the effect is mediated by non-ionizing part of the RR. Dibutyril-cAMP dose-independent increases DPab of erythrocyte membranes in the concentration range of 1-100 мкМ, but RR does not amplify this effect. Anaprilin increases dose-independent DPab in concentrations 10 and 100 μМ. The effect of maximal concentration of anaprilin (100 μМ) decreases by RR. Clotrimazol increases DPab of erythrocyte membranes in the concentration range of 0,1-10 μМ relatively control, while its maximal concentration - decreases, and the minimal level does not reliably influence on this index The action of сlotrimazol on DP in concentrations of 10-100 μМ is abolished by RR, and is not changed in the range of 0,1-1,0 μМ. Nitrendipine raises DPab of erythrocyte membranes in all of range of concentrations, and RR amplifies the effect of the drug.

CONCLUSIONS

1. There is a threshold of the biological action on cells for the ionizing component of radioisotope radiation determined by efficiency of operation their antioxidant system.2. At dose rates below a threshold, the action of ionizing radiation is mediated by its non-ionizing component, and is reversible, and therefore is determined only in the field of radiation.

[Participation of proteinkinase CK2 in regulation of human erythrocytes plasma membrane redox system activity: relative contribution of ca(2+)-dependent and ca(2+)-independent mechanisms of its activation]

Involvement of protein kinase CK2 (2.7.11.1) in modulation of live cells trans-plasma membrane electron transport was first discovered. Using human erythrocytes a decrease of plasma membrane redox system (PMRS) activity is shown under the action of specific protein kinase CK2 inhibitors. Using inhibitory analysis the activity regulation of human erythrocytes PMRS by Ca(2+)-dependent and Ca(2+)-independent mechanisms were investigated. It was shown that functional Ca(2+)-antagonists (nitrendipine and calmidazolium) significantly increased, and functional Ca(2+)-agonists to some extent reduced or did not affect the trans-plasma membrane electron transport in these cells.

[Sodium azide as indirect nitric oxide donor: researches on the rat aorta isolated segments]

A comparative investigations of heme-containing enzymes inhibitors NaN3 and NaCN effects on the rat aorta isolated segments tone has shown that NaN3 in the range of very low concentrations from 10(-9) to 10(-6) M displays pharmacological activity characteristic of nitric oxide (NO) donors, which is inhibited by NaCN. The value of vasodilatation, caused by NaN3, was also decreased in the presence of soluble guanylate cyclase inhibitor ODQ (10(-5) M). It was found that H2O2 injection to physiological solution containing NaN3 and horseradish peroxidase or catalase lead to NO2- accumulation in it, which was blocked by NaCN. The nonenzymic NaN3 oxidization by hydrogen peroxide was not found in control experiments. NaN3 physiological activity dependent on NO-donating properties of this traditional inhibitor of heme-containing enzymes is discussed.

[An enzyme-mediated mechanism of sodium nitroprusside NO-donating activity in the rat aorta]

The mechanisms of NO-mediated physiological activity of sodium nitroprusside (SNP) have been investigated in isolated rat aorta segments. It was shown, that in pretreated with 1.5 mM NaCN aorta segments SNP causes slight vasoconstriction. Heme-oxidizer K3Fe(CN)6 markedly suppressed SNP-induced vasodilatation. Also it was revealed that NaCN inhibits NO2- accumulation, which was observed in buffer solution with SNP after addition of microsomal membranes isolated from rat aorta homogenates. The great importance of cell membranes heme-containing enzymes for display of SNP NO-donating activity and the possibility of SNP-released CN- involvement in suppression of SNP-induced vasodilatation is discussed.

[The effect of nonsteroidal anti-inflammatory agents on erythrocyte osmotic resistance]

Effects of voltaren, surgam and isamben on erythrocyte membrane were studied. Voltaren and suggam, in dmM concentrations were to decrease, but in mM concentrations to increased hypotonic erythrocyte lysis. The role of erythrocyte membrane fluid is discussed with regard to this effect of the drugs, since voltaren or surgam, erythrocyte lysis even in isotonic medium at mM concentrations. In contrast to voltaren and surgam samben as had no effect on erythrocyte lysis in hypotonic or isotonic medium. In this connection, the relationship between membrane lytic effect and ulcerogenic potency of non-steroidal anti-inflammatory drugs is discussed.

[Diadenosine oligophosphates: metabolic pathways and role in regulating the functional activity of cells]

Recent data on the content and biological role of diadenosine oligophosphates in procaryotic and eucaryotic cells, animal tissues and organs are reviewed. The specific ways of their synthesis and dissociation are presented. The role of diadenosine oligophosphates in regulation of cell proliferation and as protectors from cells damage with cytotoxic agents in discussed. The perspectives uses of diadenosine oligophosphates in medicine have been examined. The role of a universal diadenosine oligophosphates system in regulation of cell biological activity is postulated.

[Effects of dephosphorylated core of 2',5'-oligoadenylate (2',5'-ApApA) on the electric activity of snail neurons]

On nervous ganglion of snail Helix pomatia was shown the effect of dephosphorylated core of 2',5'-oligoadenylate (2',5'-ApApA) on pacemaker electrical activity of RPa2 snail neurons. In experiments, solution of 2',5'-ApApA in concentration 5 x 10(-5) mol/l effected snail nervous ganglion in the course of 2 min then it was washed in the course of 2 hours.

[Methods of isolating serum lipoproteins]

The methods of serum lipoproteins separation are considered. Advantages and faults of ultracentrifugation, electrophoresis, precipitation, gel chromatography, immune-specific and filtration methods for isolation of the lipid-protein complexes are briefly characterized. The prospects of the separation methods for investigation of the lipid-protein particle structure and rapid hyperlipoproteinemias screening are discussed.