Effects of sodium selenite on apoptosis of thyrocytes in rats with experimental autoimmune thyroiditis

WANG Tingting; YAN Shengli; MA Ruixin; LI Chengqian; QI Yuqin

Abstract：Objective To investigate the effects of sodium selenite on the apoptosis in thyroid tissues of rats with autoimmune thyroiditis. Methods Wistar rats were divided into three groups: normal control, experimental autoimmune throiditis (EAT) group,and selenium prophylaxis EAT group. EAT model was established by high-dose iodine intake and pig thyroglobulin injection. Rats in se-lenium prophylaxis EAT group were given a certain amount of sodium selenite (0.2mg/kg) by intragastric administration. The levels of autoantibodies (TgAb and TmAb), changes of histology of thyroid and apoptosis of thyroid cells were detected by Radioimmunoassay,HE staining, and TUNEL, respectively. Results At the end of the experiment, the levels of TgAb in normal control, EAT group, and selenium prophylaxis EAT group were (6.94±1.13 ) %, (36.24±3.64 ) %, ( 17.23±2.90 ) %, respectively; while the levels of TmAb in the three groups were (5.96±1.40) %, (27.12±5.06) %, (15.98±2.45) %, respectively. In selenium prophylaxis EAT group, the levels of autoantibodies became much lower, the lymphocytes in thyroid were fewer, and the follicles were better, as com-pared with EAT group (P<0.05). The number of apoptotic thyroid cells were fewer in selenium prophylaxis EAT group than that in EAT group (P<0.05). Conclusion Sodium selenite can inhibit the production of autoantibodies in EAT rats, therefore protect the thyroid of rats, whose effects may be practiced through suppressing the apoptosls of thyroid cells.