METFORMIN AND BROWN ADIPOSE-TISSUE THERMOGENETIC ACTIVITY IN GENETICALLY-OBESE ZUCKER RATS

The effect of chronic metformin treatment on brown adipose tissue ther mogenetic activity was investigated in young genetically obese Zucker rats. The binding of [H-3]GDP to brown adipose tissue mitochondria, ex pression of uncoupling protein mRNA in brown adipose tissue, weight ga ins and cumulative food intakes were measured in metformin (320 mg/kg orally for 12 days) -treated obese Zucker rats as well as in pair-fed - and in ad libitum - fed control obese rats. The weight gains were id entically reduced in the metformin- and pair-fed control group compare d to the ad libitum - fed rats. Metformin also significantly reduced c umulative food intake. The binding of [H-3]GDP to brown adipose tissue mitochondria and the expression of uncoupling protein mRNA in brown a dipose tissue were not modified by metformin. It is concluded that the weight gain reducing effect of metformin in obese Zucker rats is main ly due to reduced food intake and does not involve an effect of metfor min on brown adipose tissue thermogenetic activity.