L. V. Grubska¹, V. M. Voitsitskiy², S. V. Khyzhnayk³

¹Іnstitute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Kyiv;
²National University of Life and Environmental Sciences of Ukraine, Kyiv;
³Taras Shevchenko Kyiv National University, Ukraine;
е-mail: hsv@univ.kiev.ua

The influence of ionizing radiation with low absorbed dose rate (55 mGy·min^-1) in 1, 12 and 24 hours after irradiation in doses of 0.1; 0.5 and 1.0 Gy on functional state of the electron transfer  chain of the rat small intestine mitochondria was investigated by assessment of the oxygen consumption rate. The uncoupling of oxidation and phosphorylation, a decrease of phosphorylation rate and inhibition of ATP hydrolysis reactions were established in mitochondria in dependence on the irradiation dose and time interval after irradiation. The functional peculiarities of the oxidation-phosphorylation coupling sites of the mitochondrial electron transfer chain were detected.