Alteration of radiosensitivity in metallothionein induced mice and a possible role of Zn-Cu-thionein in GSH-peroxidase system.

Based upon the observation that the mice injected with metallothionein (MT) inducing metals e.g. Cd(3mg/kg), Mn(10mg/kg) of Zn(20mg/kg) 24 hours prior to irradiation showed a marked tolerance against lethal damage due to LD50(30) level radiation and that the levels of MT in liver were elevated to three to twenty fold, i.e. 80-500 micrograms/g liver in these mice, it was assumed that the alteration of zinc turnover which accompanies the synthesis of metallothionein will correlate with a protection mechanism against radiation. Reviewing the biochemical protection mechanism of organisms against various environmental factors as well as various aspects of biological function of metals, the obtained results were discussed and it was tentatively hypothesized the role of zincthionein which could work in the glutathione peroxidase system. Finally the obtained biochemical evidences in vitro are presented.