Post-irradiation Restoration of Somatic Cell Chromosomes in Mammals

Abstract

The influence of thyroxine and its deficiency (thyroidectomy) on the frequency of chromosome aberrations in regenerating liver cells of irradiated and unirradiated rats was investigated. Thyroxine and thyroidectomy both produce chromosome damage but also have a significant effect on the amount of radiation-induced chromosome damage. Thyroxine given daily for a period of 2 months after irradiation reduced the amount of chromosome damage to the control (unirradiated) level. This is achieved either as a direct effect on repair of damage or indirectly by increasing cell-proliferation rate. Thyroidectomy increases the frequency of radiation-induced chromosome damage.