Brown Adipose Tissue (BAT) is a very interesting substance in humans. It is well-known in animals, and babies, where it acheives non-shivering thermogenesis. Wiki actually explains it rather better, and has some pictures!
Trouble is, there was quite a long period in which BAT was ignored in adult humans. Even to the point of suggesting that we adults don't have any BAT.
At heart, though, this is an inkling as to how thyroid hormones actually affect body temperature and particularly the ability to cope with cold.
Mol Cell Endocrinol. 2017 Jan 12. pii: S0303-7207(17)30015-1. doi: 10.1016/j.mce.2017.01.011. [Epub ahead of print]
Thyroid hormones and browning of adipose tissue.
Weiner J1, Hankir M1, Heiker JT1, Fenske W1, Krause K2.
1Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany.
2Department of Endocrinology and Nephrology, University Hospital, Leipzig, Germany. Electronic address: Kerstin.email@example.com.
Thyroid hormone (TH) disorders are associated with profound changes in whole body energy metabolism. A major TH target is thermogenic brown adipose tissue (BAT), which can be stimulated directly through thyroid hormone receptors (TRs) expressed in brown adipocytes and indirectly, through TRs expressed in hypothalamic neurons. White adipose tissue (WAT) adopts BAT characteristics by a diverse range of stimuli in a process referred to as browning. It is now understood that TH also induce WAT browning through peripheral and central mechanisms. In this review, we discuss evidence from animal and human studies that TH disorders are associated with changes in both BAT thermogenesis and WAT browning, thereby influencing body temperature and body weight regulation.
Copyright © 2017. Published by Elsevier B.V.