Biochemical states of zinc incorporated in the liver of mice treated with a radioelement after irradiation with a sublethal dose of gamma-rays
Izumo, Y.; Ogata, H.
Comptes Rendus des Seances de la Societe de Biologie et de ses Filiales 183(6): 564-570
1989
ISSN/ISBN: 0037-9026 PMID: 2534961 Document Number: 340303
Radioresistance has been observed in mice which have received an inorganic zinc 24 hours prior to gamma irradiation with a sublethal dose. In order to elucidate the mechanism of radioresistance, the biochemical states of the metal in filtrate extracted from the homogenated liver of the animal which have received an injection of zinc under the form of 65Zn as tracer 24 hours post irradiation, were analyzed and compared with those of non-irradiated (control) mice. Two peaks of radioactivity: P-1 and P-2, having molecular weight of about 45,000 and 20,000-25,000 respectively, were revealed by Sephadex G-75 separation. The radioactivity of P-2 (39%) from the irradiated mice is lower than that from the controls (46%). Chromatography of P-2 from control animals through DEAE-Sephadex A-50 revealed the existence of a large radioactive peak (P-U). Chromatography of P-2 from irradiated animals did not show any P-U peak. This P-U peak is composed principally from 2 to 3 proteins with a molecular weight of 12,000 to 26,000. Proteins of the P-U peak provoke a protection effect against the lethal effect of gamma-rays when they are injected into mice after irradiation.