Biopolym. Cell. 1996; 12(4):65-72.
Influence of ionizing radiation on structural organization of liver chromatin in rats of different age
1Mozzhukhina T. G., 1Litoshenko A. Ya.
  1. Gerontology Institute of the Academy of Medical Sciences of Ukraine
    67, Vyshgorodska Str., Kyiv, Ukraine, 04114


Wistar adult (6–8mo) and old (26–28mo) rats were irradiated withX-rays at a dose of 2Gy. The kinetics of release of chromatin fragments (CF) extracted by low-salt buffer from liver nuclei at Ca2+, Mg2+-endonuclease activation, and the features of repressed (RC), transcriptionally active (AC) and matrix-bound (MC) chromatin fractions were evaluated in 1 h and 4 days after irradiation. At «zero time» of endonuclease activation, the content of extracted CF increased in nuclei of intact old rats as compared with adult ones. There was an increase of this parameter in the liver nuclei of adult and old rats in 4 days and 1 h after irradiation accordingly. The release rate of CF cleavaged by activated endonuclease increased in the nuclei of old intact rats in comparison with adult animals, and changes of this rate were observed after the irradiation only in old rat nuclei. The relative amount of RC was greater both in nuclei of intact old animals and in nuclei of irradiated rats. These data testify to the resemblance of age-associated and X-ray-induced reorganization ofchromatin structure and indicate the increased susceptibility of liver chromatin of old rats to ionizing irradiation.


[1] Kristal BS, Yu BP. An emerging hypothesis: synergistic induction of aging by free radicals and Maillard reactions. J Gerontol. 1992;47(4):B107-14.
[2] Litoshenko AIa. The trigger of the aging process--in the nucleus or the mitochondria?. Izv Akad Nauk SSSR Biol. 1992;(4):645-8.
[3] Cutler RG. Superoxide dismutase, longevity and specific metabolic rate. A reply. Gerontology. 1983;29(2):113-20.
[4] Harman D. Free radicals in aging. Mol Cell Biochem. 1988;84(2):155-61.
[5] Gaubatz J, Ellis M, Chalkley R. Nuclease digestion studies of mouse chromatin as a function of age. J Gerontol. 1979;34(5):672-9.
[6] Mozzhukhina TG, Chabanny VN, Levitsky EL, Litoshenko AYa. Age-related changes of supranucleosomal structures and DNA-synthesizing properties of rat liver chromatin. Gerontology. 1991;37(4):181-6.
[7] Straaten H, Weber KJ, Keifer J. Mechanisms of inhibition of gene expression by X-rays and alpha particles. GSI-Rept. 1991. (91): 1.
[8] Mozzhukhina TG, Litoshenko AYa. Relative content and transcriptional activity of liver chromatin fractions of rats of different ages. Biopolym Cell. 1995; 11(2):69-75.
[9] Groves WE, Davis FC Jr, Sells BH. Spectrophotometric determination of microgram quantities of protein without nucleic acid interference. Anal Biochem. 1968;22(2):195-210.
[10] Rusinova GG. A study of DNA repair in the thymocytes of irradiated rats using a spectrofluorometric method. Radiobiologiia. 1990;30(3):405-7.
[11] Moskalyova EY, Ilyushina NA. DNA damage by the ionizing radiation and repair. Itogi nauki i tekhniki. VINITI 1990: (ser Radibiology; vol. 9) 5-113.
[12] Soldatenkov VA, Denisenko MF, Khodarev NN, Votrin II, Filippovich IV. Characteristics of the degradation of thymus lymphocyte DNA in the early periods after irradiation. Radiobiologiia. 1989;29(3):291-5.
[13] Sjakste TG, Sjakste NI. Chemical compounds that damage DNA. Zinatne, Riga, 1991; 152 p.
[14] Roy AK, Chatterjee B. Molecular aspects of aging. Mol Aspects Med. 1985;8(1):1-88.
[15] Malakhova LV, Gaziev AI. Changes in the nuclear proteinase activity of the liver in gamma-irradiated rats. Radiobiologiia. 1988;28(4):447-50.
[16] Gaziev AI, Malakhova LV, Kutsy? MP. Postradiation activation of proteinases associated with the hepatocyte nuclear matrix in rats. Radiobiologiia. 1987;27(2):166-70.
[17] Khanson KP, Komar VYe. Molecular mechanisms of radiation cell death. M. : Atomizdat, 1980. 174 p.
[18] Kruglova NL, Strazhevskaia NB. Mechanism of the radiation effect at the level of the supramolecular structures of eukaryotic DNA. Radiobiologiia. 1987;27(1):24-9.
[19] Zahn RK, Reinm?ller J, Beyer R, Pondeljak V. Age-correlated DNA damage in human muscle tissue. Mech Ageing Dev. 1987;41(1-2):73-114.
[20] Modern biological theries of aging. Eds H. R. Warner etc. New York: Raven press, 1987. 324 p.
[21] Sohal RS. Role of oxydative stress in cellular differentiation and cellular senescence. Age. 1987; 10(3):257-62.
[22] Riabchenko NI, Ivannik BP. Structural organization of chromatin as a factor determining the rate of its endonucleolysis in irradiated and nonirradiated thymocytes. Radiobiologiia. 1987;27(2):155-9.
[23] Chabanny VN, Mozzuchina TG, Litochenko AJ. Der Einflus von hydrocortison auf die strukturellen und funktionellen Eigenschaften des Chromatins der Leber unterchieldlich alter Ratten. Z Alternforsch. 1990; 45(2):77-88.
[24] Macieira-Coelho A. Genome reorganization during cellular senescence. Mech Ageing Dev. 1984;27(2):257-62. Review.