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ABSTRACT: Erythrocyte membrane potential was recorded via measurement of pH of the incubation medium in presence ofprothonophore. The increase of intracellular calcium concentration in presence of calcium ionophore A23187 and addition of the artificial redox-system ascorbate-phenazine methosulfate led to membrane hyperpolarization due to opening of Ca(2+)-activated potassium channels that are regulated by multiple signaling pathways. The opening of the Ca(2+)-activated potassium channels in presence of artificial redox-system ascorbate-phenazine methosulfate is mediated at least by two mechanisms including an increase in affinity of channels to calcium ions and involvement of the protein SH-groups and the components of the respiratory circuit which have beer found in erythrocyte membrane.
Rossiĭskii fiziologicheskiĭ zhurnal imeni I.M. Sechenova / Rossiĭskaia akademiia nauk 05/2006; 92(4):461-70.
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ABSTRACT: Insulin decreased A23187-induced hyperpolarization of the erythrocyte membrane in healthy donors. These data indicate that insulin plays a role in the regulation of Ca(2+)-activated potassium channels in human erythrocytes. However, insulin had little effect on hyperpolarization response of cells induced by artificial ascorbate--phenazine methosulfate donor-acceptor system. Addition of insulin to cell suspension from patients with type 2 diabetes mellitus did not modulate hyperpolarization of the erythrocyte membrane induced by A23187 or ascorbate-phenazine methosulfate, which reflects impairment of regulatory mechanisms for Ca(2+)-activated potassium channels in erythrocytes.
Bulletin of Experimental Biology and Medicine 12/2005; 140(5):499-501. · 0.27 Impact Factor
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ABSTRACT: Increase in intracellular Ca2+ concentration caused by calcium ionophore A23187 or ascorbate+phenazine methosulphate electron donor system added to erythrocyte suspension induced similar shifts in erythrocyte membrane potential. These processes are most likely mediated by Ca2+-activated potassium channels. Changes in the osmolarity of the incubation medium produced opposite effects on membrane hyperpolarization induced by A23187 or ascorbate+phenazine methosulphate in erythrocyte isolated from healthy donors, which attests to the existence of different mechanisms of regulation of Ca2+-activated potassium channels. There was no difference in the volume-dependent changes of potassium permeability in cells from patients with type II diabetes mellitus combined with arterial hypertension induced by application A23187 or electron-donor system.
Bulletin of Experimental Biology and Medicine 02/2004; 137(1):24-6. · 0.27 Impact Factor
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ABSTRACT: Increase in intracellular Ca2+ concentration caused by calcium ionophore A23187 or ascorbate+phenazine methosulphate electron donor system added to erythrocyte suspension induced similar shifts in erythrocyte membrane potential. These processes are most likely mediated by Ca2+-activated potassium channels. Changes in the osmolarity of the incubation medium produced opposite effects on membrane hyperpolarization induced by A23187 or ascorbate+phenazine methosulphate in erythrocyte isolated from healthy donors, which attests to the existence of different mechanisms of regulation of Ca2+-activated potassium channels. There was no difference in the volume-dependent changes of potassium permeability in cells from patients with type II diabetes mellitus combined with arterial hypertension induced by application A23187 or electron-donor system.
Bulletin of Experimental Biology and Medicine 12/2003; 137(1):24-26. · 0.27 Impact Factor
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ABSTRACT: We studied the effect of changes in erythrocyte volume and irreversible thermal denaturation of cytoskeleton proteins and lipid matrix on activity of Ca(2+)-activated K+ channels in erythrocytes of alcoholic and patients with II type diabetes mellitus. Changes in Ca(2+)-dependent potassium permeability of erythrocyte membrane in alcoholic patients and patients with II type diabetes mellitus are related to modification of cytoskeleton, rather than to changes in lipid matrix.
Bulletin of Experimental Biology and Medicine 11/2002; 134(4):345-8. · 0.27 Impact Factor
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Biulleten' eksperimental'noĭ biologii i meditsiny 02/1999; 127(1):77-80.
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ABSTRACT: In patients with lung cancer and malignant tumors of the head and neck, erythrocyte hyperpolarization associated with the
opening of Ca2+-activated potassium channels develops with lower rate and amplitude compared with that in healthy donors. Restoration of
normal membrane potential is Ca2+-ATPase-dependent. The rate of restoration is significantly higher in patients with tumors. Two groups with different hyperpolarization
response and their dynamics during chemotherapy were identified in patients with lung cancer. Ca2+-induced erythrocyte hyperpolarization and its dynamics during cytostatic therapy depend on tumor localization and histological
type.
Bulletin of Experimental Biology and Medicine 12/1998; 127(1):69-72. · 0.27 Impact Factor
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I V Petrova,
E A Stepovaia,
I B Sokolova,
V E Gol'dberg,
N Iu Chasovskikh,
K G Koreshkova,
N G Bazhenova,
M V Kolosova,
M B Baskakov,
V V Novitskiĭ,
M A Medvedev
Biulleten' eksperimental'noĭ biologii i meditsiny 09/1997; 124(8):195-8.
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V V Novitskiĭ,
N Iu Chasovskikh,
E A Stepovaia,
V E Gol'dberg,
Z D Kitsmaniuk,
M V Kolosova,
A N Mikhaĭlenko,
K G Koreshkova,
N G Bazhenova, I V Petrova,
I B Sokolova
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ABSTRACT: Scanning electron microscopy of the relief of the surface of peripheral red blood cells in patients with tumors of the head and neck (cancer of the tongue, larynx, and fundal buccal mucosa) of stages II-III and with stages III-IV lung cancer revealed similar changes, characterized by a manifest drop in the count of discocytes and increased share of transitional, prehemolytic, and degenerative forms of cells.
Klinicheskaia laboratornaia diagnostika 09/1997;
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Biulleten' eksperimental'noĭ biologii i meditsiny 07/1997; 123(6):653-5.
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I. V. Petrova,
E. A. Stepovaya,
I. B. Sokolova,
V. E. Gol'dberg,
N. Yu. Chasovskikh,
K. G. Koreshkova,
N. G. Bazhenova,
M. V. Kolosova,
M. B. Baskakov,
V. V. Novitskii,
M. A. Medvedev
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ABSTRACT: Characteristics of changes in the membrane potential induced by increased Ca2+ inward current in patients with lung cancer are presented. Both the amplitude and the rate of hyperpolarization induced by
opening of Ca2+-activated potassium channels are markedly decreased in erythrocytes from patients in comparison with healthy donors. Under
conditions of moderate Ca2+ inward current, hyperpolarization is followed by restoration of the membrane potential. This process is more rapid in cancer
patients. It is shown that the parameters of hyperpolarization, in their dynamics during antitumor therapy depend on the type
of lung cancer.
Bulletin of Experimental Biology and Medicine 01/1997; 124(2):795-797. · 0.27 Impact Factor
