[Effects of ethylenethiourea on synthesis and secretion of thyroglobulin and iodide uptake of FRTL-5 cells].

To investigate the effects of ethylenethiourea (ETU) on thyroglobulin (TG) secretion and iodide uptake of FRTL-5 cells. FRTL-5 cells were treated with 30, 150 and 270 microg/ml ETU, the cytotoxicity was tested by MTT and 3H-TdR, the synthesis and secretion of TG were analyzed by radioimmunoassay (RIA) and immunocytochemical method (ICC), the influence of ETU on tg and nis gene was determined by RT-PCR, and the iodide uptake of FRTL-5 cells was examined by isotopic tracer method. There is no significant cytotoxicity of ETU on FRTL-5 cells. The concentration of TG in the culture was decreased at 150 microg/ml and 270 microg/ml of ETU, and the concentration of TG and the transcription of tg gene in the cells were not obviously changed. The transcription of nis gene was markedly decreased at all dosages of ETU, but the iodide uptake of FRTL-5 cells was significantly decreased at 150 microg/ml and 270 microg/ml of ETU. The secretion of TG of FRTL-5 cells may be depressed by ETU, and the synthesis of TG could not be markedly changed. The transcription of nis gene could also be influenced by all dosages of ETU, but the iodide uptake of FRTL-5 cells was changed only at high levels of ETU.