RESUMO
The body's immunological responses were examined in thyroid damage caused by the incorporation of varying 131I doses. The in-take of 131I in doses of 37, 74, and 148 KBc/g body weight caused reductions in the murine blood concentrations of thyroxin following 30, 60, and 180 days. The blood levels of triiodothyronine decreased 180 days after administration of 131I in a dose of 74 KBc/g body weight and 30, 60, and 180 days after incorporation of the radioisotope in a dose of 148 KBk/g body weight. Decreased concentrations of the both hormones were followed by the suppression of a humoral immune response to sheep red blood cells, diminished cell-mediated immunity in the mixed culture of lymphocytes. The inhibition of immune responses was correlated with the changes in the level of triiodothyronine.