Brown Adipose Tissue
BAT is a thermogenic organ. In contrast to white adipose tissue (WAT), the primary function of BAT is to produce heat by the process of nonshivering thermogenesis (NST). This process is enabled by the presence of the unique mitochondrial protein, UCP1, which functions by uncoupling the process of substrate oxidation from ATP production, releasing the oxidized energy as heat.
The re-emergence of scientific interest in BAT is fueled by its recent rediscovery in adult humans but it is, by no means, a 'new human organ'. Historical reports of its presence date back to 1908 when Bonnot described an interscapular gland in adult cadavers. Brown adipocytes mainly use fatty acids as a substrate, and NST is activated by sympathetic stimulation on cold exposure. It is well known that BAT recruitment is enhanced by cold acclimation but the roles of other physiological and pharmacological agents that can recruit BAT and activate NST are less clear. Although studies have revealed the role of pharmacological agents such as novel β3-adrenoceptor agonists in activating BAT to increase energy expenditure their application to humans is as yet not feasible.
Expert Rev Endocrinol Metab. 2013;8(2):123-125. © 2013 Expert Reviews Ltd.