Hepatic thermogenesis relation to food intake in the conscious rat

It is well known that the body temperature increases during food intake. However, probably because of high thermal conduction within the body, it is rather difficult to determine the main organ that is the source of participates heat production in association with food intake. Our study revealed that increased temperature in the liver during food intake was more predominant than that in the other parts of the abdomen. To further confirm this, we attempted to measure the temperature of both the liver and blood in the portal vein, simultaneously. The temperature of the liver was always higher than that of the portal blood. This implies that hepatic thermogenesis is continuous. The difference between these two temperatures may indicate whether or not hepatic thermogenesis contributes to the increase in body temperature during food consumption. It becomes apparent that the participation of thermogenesis of the liver, along with that of the brown adipose tissue in body temperature increase, is influenced by the composition of food, such as high or low protein in the diet.