Biopolymers and cell. 2009; 25 (3): 234 - 239

Genotoxicity estimation of tumor growth in organisms preliminary irradiated at low doses

M. M. Marchenko, G. P. Kopylchuk, I. O. Shmarakov, L. V. Blynda

Aim. To determine a level of nuclear DNA stability in the liver and blood lymphocytes of an organism with Guerin’s carcinoma, developing at low doses irradiation background. Methods. Single cell DNA microelectrophoresis, electrophoresis of total and fragmented DNA, spectrophotometer titration of DNA complexes with pironin G. Results. The damage of nuclear DNA in the liver and blood lymphocytes at the initial stages after preliminary irradiation at low doses (daily dose 36.12×10–4 Kl/kg) has mono- directional character, mostly expressed in the blood lymphocytes by increasing of 10–50 kb, 2 kb and less DNA fragments amount. At the same time, nuclear DNA damage induced by radiation in the liver and blood lymphocytes of the organism with the developing tumor manifests itself by a high rate of destructivity at the terminal stages of Guerin’s carcinoma growth only, mostly revealed in the liver of irradiated rats with tumor. Conclusions. The observed instability of nuclear DNA in the lymphocytes and liver may reduce their adequate functioning that could promote oncogenesis in the irradiated organism, and also cause an increase of drugs genotoxicity at the efforts of malignant growth elimination.

Key words: nuclear DNA, liver, lymphocytes, genotoxicity.