| Research Abstract |
The following experiments were done to clarify the role of brown adipose tissue (BAT) in obesity in human. 1) Animal study: BAT, liver and rectal temperatures and resting metabolic rate were measured before and at 30-min intervals for 7 h following the tube feeding of 40 kcal or 85 kcal liquid diet (carbohydrate 11.5%, fat 86.7%, protein 1.8%) or distilled water in Sprague-Dawley rats fasted for 24 h at 33 ﾟC. Forty kcal feeding increased liver temperature within 30 min and after 3h following feeding, whereas, BAT temperature increased only after 3 h. However, 85 kcal feeding resulted in greater increases in two peaks of liver and BAT temperatures, respectively. 2) Human study: The changes of temperature in cervical and interscapular BAT regions were monitored by thermography before and after ingestion a high calorie liquid diet (900 kcal: carbohydrate 50%, fat 30%, protein 16%) in 30 subjects with simple obesity and 30 with normal weight. Temperatures in these regions were increased between 30 and 60 min after diet loading. A correlation was observed between the response in temperatures 30 min after diet loading and basal metabolic rate in obese (r=0.8043, p<0.002) and normal (r=0.3677, p<0.05) subjects. In addition, the resting metabolic rate increased within 30 min and after 3 h following diet loading in the 10 obese subjects tested.
These results suggest that BAT may play a role in obesity not only in rodents, but also in human.
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