Effect of acute cold-exposure on norepinephrine turnover and thermogenesis in brown adipose tissue and metabolic rate in MSG-induced obese mice.

Mice treated neonatally with monosodium-L-glutamate (MSG) are known to develop into obese adults without hyperphagia, which are characterized by the reduced levels in the resting metabolic rate (RMR) and the thermogenesis of brown adipose tissue (BAT) in the thermoneutral environment. The present study revealed that an acute cold-exposure (5 degrees C, 1 h) of these animals resulted in the increase in norepinephrine turnover and mitochondrial-5'-diphosphate (GDP) binding in the interscapular BAT as well as the guanosine RMR, suggesting a normal thermogenic responsiveness of BAT to cold.