EFFECT OF CHRONIC TREATMENT WITH ICI-D7114, A SELECTIVE BETA(3)-ADRENOCEPTOR AGONIST, ON MACRONUTRIENT SELECTION AND BROWN ADIPOSE-TISSUE THERMOGENESIS IN SPRAGUE-DAWLEY RATS

ICI D7114 is a selective beta(3)-agonist which stimulates brown adipos e tissue thermogenesis. In the present study the effects of 18 days tr eatment with ICI D7114 (2 mg/kg/day orally) on macronutrient selection and brown adipose tissue thermogenesis were investigated in Sprague-D awley rats. The rats were maintained on a free-feeding self-selection paradigm with three pure macronutrient diets of carbohydrate, fat and protein. Treatment with ICI D7114 did not change the macronutrient sel ection or total calories consumed by the rats. To monitore the thermog enic activation of brown adipose tissue the binding of [H-3]CDP to bro wn adipose tissue mitochondria was measured. The treatment with ICI D7 114 increased the binding of GDP both when expressed as total binding per lobe (P < 0.001) and per mg of protein (P < 0.01). It is concluded that ICI D7114, used in doses affecting brown adipose tissue thermoge nesis, does not change the macronutrient selection or total energy int ake in Sprague-Dawley rats.