Estradiol decreases iodide uptake by rat thyroid follicular FRTL-5 cells

• Main Authors: Furlanetto T.W., Nunes Jr. R.B., Sopelsa A.M.I., Maciel R.M.B.
• Format: Article
• Language: English
• Published: Associação Brasileira de Divulgação Científica 2001-01-01
• Series: Brazilian Journal of Medical and Biological Research
• Subjects: iodide uptake; estradiol; thyroid; follicular cells
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000200015

Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 ± 0.370 to 2.085 ± 0.364 pmol I-/µg DNA at 1 ng/ml (P<0.02), to 1.970 ± 0.302 pmol I-/µg DNA at 10 ng/ml (P<0.003), and to 2.038 ± 0.389 pmol I-/µg DNA at 100 ng/ml (P<0.02). In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 ± 0.408 to 7.312 ± 0.506 pmol I-/µg DNA (P<0.02). A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis.