Action of Thyroid Hormones
Thyroid hormone is produced in the thyroid gland by the use of iodine from food.
Thyroid hormones are critical determinants of brain and somatic development in infants and of
metabolic activity in adults (Davis et al., 2018). They affect the function of virtually every organ
system. Thyroid hormone biosynthesis and secretion are maintained within narrow limits by a
regulatory, mechanism that is very sensitive to minute changes in circulating hormone
concentrations. Third hormones acts through modifying gene transcription in virtually all tissues
to alter rates of protein synthesis and substrate turnover, when it is in the form of
triiodothyronine (T3). Thyroid hormone is recognized to occur through direct binding of thyroid
receptor to DNA, but can be due to indirect binding of TR to DNA or even without DNA binding
(Minakhina et al., 2020). Thyroid hormones affects every cell and all the organs of the body.
They regulate the rate at which calories are burned, hence affecting weight loss or weight gain.
They can also slow down or speed up the heartbeat, and can raise or lower body temperature.
Thyroid hormones also influence the rate at which food moves through the digestive tract. They
control the way muscle contracts and the rate at which dying cells are replaced.
References
Davis,(P.(J., Leonard,(J.(L., Lin,(H., Leinung,(M., & Mousa,(S.(A. (2018). Molecular basis of
Nongenomic actions of thyroid hormone.(Vitamins and Hormones, 67-
96.(https://doi.org/10.1016/bs.vh.2017.06.001
Minakhina,(S., Bansal,(S., Zhang,(A., Brotherton,(M., Janodia,(R., De Oliveira,(V., Tadepalli,(S.,
& Wondisford,(F.(E. (2020). A direct comparison of thyroid hormone receptor protein
levels in mice provides unexpected insights into thyroid hormone action.(Thyroid,(30(8),
1193-1204.(https://doi.org/10.1089/thy.2019.0763
