The effects of chronic treatment with the beta 3-adrenergic receptor agonist CGP-12177 on uncoupling protein (UCP) synthesis in interscapular brown adipose tissue (IBAT), various white fat depots and skeletal muscle have been examined in the mouse (daily injection for 15 days at a dose of 0.5 mg/kg). The treatment increased the IBAT UCP content and led to the expression of UCP in inguinal white adipose tissue. The increase in IBAT UCP content took place in the absence of tissue hypertrophy, and despite the increase in total body UCP content, no changes in body weight were observed after the treatment. The results confirm that ectopic expression of UCP in non-BAT tissues can be induced after chronic adrenergic stimulation.