Effects of repeated potassium iodide administration on genes involved in synthesis and secretion of thyroid hormone in adult male rat

Mol Cell Endocrinol. 2018 Oct 15;474:119-126. doi: 10.1016/j.mce.2018.02.017. Epub 2018 Feb 26.


Background: A single dose of potassium iodide (KI) is recommended to reduce the risk of thyroid cancer during nuclear accidents. However in case of prolonged radioiodine exposure, more than one dose of KI may be necessary. This work aims to evaluate the potential toxic effect of repeated administration of KI.

Methods: Adult Wistar rats received an optimal dose of KI 1 mg/kg over a period of 1, 4 or 8 days.

Results: hormonal status (TSH, FT4) of treated rats was unaffected. Contrariwise, a sequential Wolff-Chaikoff effect was observed, resulting in a prompt decrease of NIS and MCT8 mRNA expression (-58% and -26% respectively), followed by a delayed decrease of TPO mRNA expression (-33%) in conjunction with a stimulation of PDS mRNA expression (+62%).

Conclusion: we show for the first time that repeated administration of KI at 1 mg/kg/24h doesn't cause modification of thyroid hormones level, but leads to a reversible modification of the expression of genes involved in the synthesis and secretion of thyroid hormones.

Keywords: Potassium iodide; Repeated prophylaxis; Thyroid gland; Thyroid hormones; Wolff-chaikoff effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport / drug effects
  • Gene Expression Regulation / drug effects*
  • Iodine / urine
  • Male
  • Pituitary Gland / drug effects
  • Pituitary Gland / metabolism
  • Potassium Iodide / administration & dosage*
  • Potassium Iodide / pharmacology*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats, Wistar
  • Thyroid Gland / drug effects
  • Thyroid Gland / metabolism
  • Thyroid Hormones / biosynthesis*
  • Thyroid Hormones / blood


  • RNA, Messenger
  • Thyroid Hormones
  • Potassium Iodide
  • Iodine