The effect of electromagnetic radiation on indexes of antioxidant defense in rat erythrocytes and blood plasma

Цель исследования - изучение влияния электромагнитного излучения дециметрового диапазона на показатели антиоксидантной защиты в эритроцитах и плазме крови крыс. Методика. Эксперименты выполнены на крысах находившихся под влиянием электромагнитного поля дециметрового диапазона в течение 3-х мес. Проведен хемилюминесцентный анализ эритроцитов и плазмы крови животных. Интенсивность свободно радикального окисления в эритроцитах и плазме крови оценивали по показателям: максимальной интенсивности хемилюминесценции (Imax); светосуммы (S); светосуммы после максимального значения хемилюминесценции S(imax); коэффициентам Zlmax и Dec. Спектрофотометрически определяли содержание восстановленного глутатиона в эритроцитах. В плазме крови определяли содержание церулоплазмина, меди и железа. Анализ этих показателей был проведен в динамике исследования через 30, 60 и 90 сут. Результаты. Длительное (в течение 3 мес) нахождение животных в условиях действия электромагнитного поля приводит к изменениям показателей хемилюминесценции эритроцитов. Изменение показателей Imaх, S, Simax свидетельствует о нарушении процессов свободнорадикального окисления. В эритроцитах периферической крови крыс при этом установлено повышение содержания глутатиона. В плазме крови выявлено увеличение концентрации церулоплазмина и меди, снижение содержания железа. Заключение. Длительное нахождение животных в условиях действия электромагнитного поля приводит к нарушению равновесия в прооксидантно-антиоксидантной системе в эритроцитах. Антиоксиданты глутатион и церулоплазмин являются мишенью для действия электромагнитного излучения дециметрового диапазона. Установлено влияние длительного электромагнитного излучения на показатели минерального обмена: снижение содержания железа и увеличение содержания меди в плазме крови. The aim of the research was to study the effect of decimeter-range electromagnetic radiation on indexes of antioxidant defense in rat erythrocytes and blood plasma. Methods. Experiments were performed on rats exposed to decimeter-range electromagnetic field for three mos. Chemiluminescent analysis of erythrocytes and blood plasma was performed. Intensity of free-radical oxidation in erythrocytes and plasma was evaluated by parameters of maximum chemiluminescence intensity (Imax), light sum (S), the light sum after the maximum chemiluminescence value (imax), and ZImax and Dec coefficients. The content of reduced glutathione in peripheral blood erythrocytes and the plasma contents of ceruloplasmin, iron and copper were measured spectrophotometrically at 30, 60, and 90 days. Results. A long-term exposure of animals to the electromagnetic field for 3 mos. led to changes in chemiluminescent parameters of erythrocytes. The changes in Imax, S, and Simax indicated impairment of free-radical oxidation processes. The content of glutathione was increased in peripheral blood erythrocytes. The plasma contents of ceruloplasmin and copper were increased whereas the content of iron was decreased. Conclusion. The long-term exposure of animals to the electromagnetic field results in an imbalance of the erythrocyte pro-/antioxidant system. The antioxidants glutathione and ceruloplasmin are targets for the decimeter-range electromagnetic radiation. The study demonstrated the effect of long-term electromagnetic radiation on indexes of mineral metabolism evident as a decrease in the content of iron and an increase in the content of copper in the blood plasma.

The role of the dehydration stage in the post-hypertonic hemolysis of mammalian erythrocytes

The aim of this study was to assess the level of damage to mammalian erythrocytes under post-hypertonic shock depending on the concentration of NaCl in the dehydration medium and to determine the effect of hypertonic NaCl solutions on the condition of mammalian erythrocytes by flow cytometry. To achieve this goal, spectrophotometric and cytometry research methods were used. The data obtained showed that post-hypertonic lysis of mammalian erythrocytes depends on the concentration of NaCl in the dehydration medium. The most sensitive to the effects of post-hypertonic shock are rat erythrocytes, the least sensitive are rabbit cells. Cytometry studies revealed significant changes in the histograms of the distribution of erythrocytes of all mammalian species with increasing salt concentration in the dehydration medium. These changes are species-specific and are probably related to changes in cell volume and morphology. The data revealed a relationship between the level of post-hypertonic hemolysis and the values of such indicators as the median distribution and the coefficient of variation. Thus, an increase in the sensitivity of mammalian erythrocytes to post-hypertonic shock with increasing salt concentration in dehydration medium was usually accompanied by a decrease in the median cell division, and higher values of the coefficient of variation are characteristic of mammalian erythrocytes resistant to post-hypertonic shock.

Impact of membranetropic compounds on the sensitivity of mammalian erythrocytes to the posthypertonic shock action

The effect of cationic trifluoperazine (TFP) and nonionic decyl-β,D-glucopyranoside (DGP) on the sensitivity of human, rabbit and rat erythrocytes to the action of posthypertonic shock (PHS) at 0 °C was studied in this research. Trifluoperazine shows a high antihemolytic activity under conditions of PHS of human and animal erythrocytes at slight differences of values of effective concentrations. The value of antihemolytic activity of TFP for human and rabbit erythrocytes is ~ 60 %, and for rat cells the efficiency of this compound is approximately 1.4 times higher. The values of antihemolytic activity of DGP under PHS conditions of human and rat erythrocytes are comparable and amounts to 62 and 66 %, respectively. Significant differen­ces of this parameter (72 %) were found for rabbit cells compared with human erythrocytes. It was found that the size of plateau (the range of concentrations of amphiphilic compounds within the minimum level of erythrocyte hemolysis was observed) cationic TFP and nonionic DGP are significantly different. Thus, TFP has a narrow plateau (100–200 μmol/L), while DGP has a rather wide one (400–1600 μmol/L). In addition, a shift of the plateau concentrations of DGP to the region of higher values compared with TFP is observed, which is probably due to the fact that the value of the critical micelle concentration DGP is higher than TFP. Moreover, a shift of plateau concentrations of DGP to the region of higher values compared with TFP is observed, that is probably due to the fact that the value of the critical micelle concentration DGP is higher than TFP one. It was established that under PHS conditions of human erythrocyte, both compounds (TFP and DGP) show a commensurate antihemolytic activity. At the same time, for rabbit cells, DGP is more effective compared with TFP, and for rat erythrocytes, on the contrary, the efficiency of TFP is higher than DGP. This may be due to differences in the phospholipid composition of mammalian erythrocyte membranes. The results suggest that under PHS conditions the efficacy of membrane-tropic compounds is most likely due to their ability to incorporate into membrane to the defect formation areas, and thus significantly increase the critical hemolytic volume of cells, as a result, prevent their destruction.

Basic components of glutathion system in rat erythrocytes under conditions of toxic damage on the background of an alimental protein lack

The article is devoted to the study of the main components of the glutathione system under conditions of toxic damage against the background of nutritional protein deficiency: the content of reduced and oxidized glutathione with the determination of the GSH/GSSG ratio, the activity of glutathione-dependent enzymes – glutathione peroxidase, glutathione transferase, glutathione reductase, and glucose-6-phosphate dehydrogenase. The concentration of reduced glutathione in the erythrocyte hemolysate was studied using Elman's reagent after deproteinization of the samples. Glutathione transferase activity was determined by the rate of formation of glutathione S conjugates by reacting reduced glutathione with a substrate of 1-chloro-2.4-dinitrobenzene. Glutathione peroxidase activity was evaluated by the formation of oxidized glutathione. The activity of glutathione reductase in erythrocytes was determined by the method, is based on measuring the oxidation rate of NADPH+H+, which is recorded by decreasing absorption at a wavelength of 340 nm. A decrease in the ratio of GSH/GSSG in rat erythrocytes under conditions of toxic damage against a nutritional deficiency of protein is indicated by a functional shift in the thiol-disulfide balance towards increased use of the reduced form of glutathione for antioxidant protection. It was established that toxic damage is a key factor in reducing the level of glutathione transferase against the background of an increase in glutathione peroxidase activity in rat erythrocytes, the activation of which probably prevents the progression of LPO processes. At the same time, under conditions of toxic damage, against the background of alimentary protein deficiency, a decrease in glutathione reductase and glucose-6-phosphate dehydrogenase activity is observed, which leads to blocking of the first stage of glucose-6-phosphate metabolism in the pentose phosphate cycle, resulting in a decrease in the amount of NADPH and, accordingly reduced glutathione.

The B Subunit of PirABvp Toxin Secreted from Vibrio parahaemolyticus Causing AHPND Is an Amino Sugar Specific Lectin

Vibrio parahaemolyticus (Vp) is the etiological agent of the acute hepatopancreatic necrosis disease (AHPND) in Penaeus vannamei shrimp. Vp possesses a 63–70 kb conjugative plasmid that encodes the binary toxin PirAvp/PirBvp. The 250 kDa PirABvp complex was purified by affinity chromatography with galactose-sepharose 4B and on a stroma from glutaraldehyde-fixed rat erythrocytes column, as a heterotetramer of PirAvp and PirBvp subunits. In addition, recombinant pirB (rPirBvp) and pirA (rPirAvp) were obtained. The homogeneity of the purified protein was determined by SDS-PAGE analysis, and the yield of protein was 488 ng/100 μg of total protein of extracellular products. The PirABvp complex and the rPirBvp showed hemagglutinating activity toward rat erythrocytes. The rPirAvp showed no hemagglutinating capacity toward the animal red cells tested. Among different mono and disaccharides tested, only GalNH2 and GlcNH2 were able to inhibit hemagglutination of the PirABvp complex and the rPirBvp. Glycoproteins showed inhibitory specificity, and fetuin was the glycoprotein that showed the highest inhibition. Other glycoproteins, such as mucin, and glycosaminoglycans, such as heparin, also inhibited the activity. Desialylation of erythrocytes enhanced the hemagglutinating activity. This confirms that Gal or Gal (β1,4) GlcNAc are the main ligands for PirABvp. The agglutinating activity of the PirABvp complex and the rPirBvp is not dependent on cations, because addition of Mg2+ or Ca2+ showed no effect on the protein capacity. Our results strongly suggest that the PirBvp subunit is a lectin, which is part of the PirA/PirBvp complex, and it seems to participate in bacterial pathogenicity.