Problems of Radiation Medicine and Radiobiology

V. V. Zhirnov¹, I. N. Iakovenko¹, V. M. Voitsitskiy², S. V. Khyzhnyak², О. G. Zubrikova-Chugainova³,
V. A. Gorobetz³

¹Institute of Bioorganic Chemistry & Petrochemistry of National Academy of Sciences of Ukraine., 1 Murmanska St., Kyiv, 02660, Ukraine
²National University of Life and Environmental Sciences of Ukraine, 15 Heroyiv Oborony St., Kyiv, 03041, Ukraine
³Public institution "Institute of Heart" of the Ministry of Health of Ukraine, 5A Bratyslavska St., Kyiv, 02660, Ukraine

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 44.4 kBq•l^-1.
Results. The radioisotope radiation of ⁹⁰Sr/⁹⁰Y (RR, 15 mGy•h^-1) increases an absolute value of erythrocyte membranes DP (DPab), and its action is reversible. It specifies the effect is mediated by nonionizing part of the RR. Dibutyril-cAMP dose-independent increases DPab of erythrocyte membranes in the concentration range of 1–100 μМ, but RR does not amplify this effect. Anapriline increases dose-independent DPab in concentrations 10 and 100 mМ. The effect of maximal concentration of anapriline (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 effectivity of operation their antioxidant system.
2. At dose rates below a threshold, the action of ionizing radiation is mediated by its nonionizing component, and is reversible, and therefore is determined only in the field of radiation.

Key words: Gardos channel, zeta potential, β-radiation, strontium-90, human erythrocytes, biomembranes.

Problems of radiation medicine and radiobiology. 2015;20:490-499.