Reawakened interest in type III iodothyronine deiodinase in critical illness and injury

Nat Clin Pract Endocrinol Metab. 2008 Mar;4(3):148-55. doi: 10.1038/ncpendmet0727. Epub 2008 Jan 22.


Thyroid hormones influence gene expression in virtually all vertebrate tissues. Precise regulation of the active endogenous ligand, 3,5,3'-triiodothyronine (T(3)), is achieved by the sequential removal of iodine moieties from the thyroid hormone molecule. Type III iodothyronine deiodinase (D3) is the major inactivating enzyme terminating the action of T(3) and preventing activation of the prohormone, thyroxine (T(4)). Recent studies have revealed the induction of high D3 activity in diverse animal models of tissue injury including starvation, cryolesion, cardiac hypertrophy, infarction, and chronic inflammation. By analyzing serum and tissues taken from hospitalized patients at the time of death, investigators have also documented the robust induction of D3 activity in several human tissues that normally have none, including the liver and skeletal muscle, and shown clinically relevant consequences to systemic thyroid status. These studies reveal a novel role of D3 in the tissue response to injury and in the derangement of thyroid hormone homeostasis commonly observed during critical illness.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Critical Illness*
  • Euthyroid Sick Syndromes / blood
  • Euthyroid Sick Syndromes / metabolism
  • Euthyroid Sick Syndromes / pathology
  • Humans
  • Iodide Peroxidase / blood
  • Iodide Peroxidase / metabolism*
  • Thyroid Hormones / blood
  • Thyroid Hormones / metabolism*
  • Wounds and Injuries / enzymology*


  • Thyroid Hormones
  • iodothyronine deiodinase type III
  • Iodide Peroxidase