RESUMO
OBJECTIVE: To study the impact of N' N-methylene-bis on thyroglobulin produced by FRTL-5 cells, and to explore the potential of using FRTL-5 cells to screen environmental thyroid hormone disruptors in vitro. METHODS: The FRTL-5 cells were treated with 0.1, 1.0 and 10.0 microg/mL N'N-methylene-bis for 48 hours, respectively. The concentrations of thyroglobulin in the medium of the treated cells were detected by radioimmunoassay. The expression of thyroid peroxidases in the FRTL-5 cells was assessed by enzyme cytochemistry technique. The ultrastructure of the cells was also observed. RESULTS: The FRTL-5 cells treated with 0.1 and 1.0 microg/mL of N' N-methylene-bis produced less thyroglobulin than the controls (P < 0.05). No thyroglobulin was detected with the cells treated with 10.0 microg/mL of N' N-methylene-bis. No difference in the expression of thyroid peroxidases was found between the treated cells and the controls. The treated cells had expanded rough endoplasmic reticulum. CONCLUSION: N' N-methylene-bis disrupts the bio-function of thyroid by damaging the rough endoplasmic reticulum of thyroid follicular cells. FRTL-5 cells can be used for screening thyroid hormone disruptors in vitro.
