Thyroid hormone

German: Schilddrüsenhormon

1 Definition

Thyroid hormones are blood-bound signalling substances (i.e. hormones) that are formed and released by the thyroid gland or that are formed from other organs from primary thyroid hormones.

2 Classification

Thyroid hormones belong to two substance classes and the following subclasses:

• True thyroid hormones based on the thyronamine skeleton
  • Iodothyronines
    • Thyroxine (T4)
    • Triiodothyronine (T3)
    • Reverse-T3
    • Three different diiodothyronines
    • Two different Monoiodothyronines
  • Iodothyroacetats
  • Thyronamines
• Peptide hormone
  • Calcitonin

3 Function

The two iodine-containing amines thyroxine (T4) and triiodthyronine (T3) control metabolic activity and differentiation of and in the organism, calcitonin is involved in regulation of calcium metabolism, but its role seems to be inferior when compared to parathyroid hormone and D-hormone. By contrast, the impact of T4 and T3, whose secretion is controlled by thyrotropic feedback control, is very high.

4 Pathologic conditions and clinical aspects

Overprovision of the organism with thyroid hormones is referred to as thyrotoxicosis, lack of thyroid hormones as Hhypothyroidism.

5 References

• D. S. Cooper, P. W. Ladenson. The Thyroid Gland. In: D. G Gardner und D. Shoback. Greenspan's Basic & Clinical Endocrinology. McGraw-Hill, New York 2011. ISBN 9780071622431. S. 163-226
• P. Kopp. Thyroid Hormone Synthesis. In: L. E. Bravermann, D. S. Cooper. Werner & Ingbar's The Thyroid. Lippincott Williams & Wilkins, Philadelphia 2013. ISBN 9781451120639. S. 48-74
• Mondal S, Raja K, Schweizer U, Mugesh G. Chemistry and Biology in the Biosynthesis and Action of Thyroid Hormones. Angew Chem Int Ed Engl. 2016 Jun 27;55(27):7606-30. doi: 10.1002/anie.201601116. PMID 27226395.