J. Phys. IV France
Volume 107, May 2003
Page(s) 987 - 992

J. Phys. IV France
107 (2003) 987
DOI: 10.1051/jp4:20030464

A prior administration of heavy metals reduces thymus lymphocyte DNA lesions and lipid peroxidation in gamma-irradiated mice

A.N. Osipov1, N.I. Ryabchenko2, B.P. Ivannik2, L.A. Dzikovskaya2, V.I. Ryabchenko2 and G.Ya. Kolomijtseva3

1  Moscow Scientific and Industrial Association Radon, 9/154 Kuusinena Str., 123308 Moscow, Russia
2  Medical Radiology Research Center, Russian Academy of Medical Sciences, Korolev Str. 4, Obninsk, 249020 Kaluga Region, Russia
3  A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, 119899 Moscow, Russia

In the present work we report that a prior injection of Pb, Cd or Zn salt solutions in SHK male mice decreases the effect followed $\gamma$-irradiation on thymus lymphocyte DNA structure and level of lipid peroxidation. It is assumed that the observed phenomenon is caused by activation of protective mechanisms of cells, expression of the genes of antioxidant proteins such as the metallothioneins, etc. Indeed the measurement of malondialdehyde (MDA) in blood plasma showed that the injection of metal salt solutions at median lethal doses a half hour before $\gamma$-irradiation (1 Gy) causes the decrease of the MDA contents at 48 h after irradiation on 100% (Zn), 70% (Cd) and 20% (Pb). However we found that combined exposure of the mice also results to significant decrease of the thymus lymphocytes total number of as compared to the irradiation without metals. The elimination of the cells with high level of DNA lesions and existence at least a subset of cells which would survive the current oxidative stress ( $\gamma$-irradiation) possibly represents one path-way of the survival of individual organism facing stress. ln turn the observed decrease of the lesion levels may be reflection of the cell number change.

© EDP Sciences 2003