It is located mainly in adipose tissue and is involved in the regulation of lipolysis and thermogenesis . Some β 3 agonists have demonstrated antistress effects in animal studies, suggesting it also has a role in the central nervous system (CNS). β 3 receptors are found in the gallbladder, urinary bladder, and in brown adipose tissue . Their role in gallbladder physiology is unknown, but they are thought to play a role in lipolysis and thermogenesis in brown fat. In the urinary bladder it is thought to cause relaxation of the bladder and prevention of urination.