STUDY ON THE EFFECT OF IODINE EXCESS ON CATHEPSINS IN RAT THYROID CELLS / 营养学报

ABSTRACT

Objective: To explore the effect of iodine overdose on cathepsin B and D in thyroidcell line (FRTL). Method: The cells were treated with potassium iodide (0, 1, 5, 10, 50 and 100mmol/L). After treatment 6, 12, 24, 48 and 72 hours, the cells were collected. The activities of cathepsin B (CB) and cathepsin D (CD) were assayed by fluorospectrophotometry and Lowry, respectively. The mRNA levels of CB and CD were determined with real-time PCR. Results: After 12 and 24 hours, the activities of CB and CD, treated by 50mmol/L potassium iodide were decreased significanty. The mRNA levels of CB and CD of 50mmol/L potassium iodide group were decreased significanty after treatment 24 hours. Conclusion: The decreased activities of CB and CD were one of reasons of thyroid colloid retention resulted from iodine excess.