Thermogenic response to glucagon in cold-acclimated mice

Heat production after injection of glucagon and norepinephrine was measured in warm- and cold-acclimated mice. Glucagon and norepinephrine in a dose of 100 microgram/100 g caused a marked increase in oxygen consumption. Heat production after administration of glucagon and norepinephrine was significantly potentiated by cold acclimation. A significant positive correlation was observed between the increase in oxygen consumption after injection of glucagon or norepinephrine and the weight of brown adipose tissue in warm- and cold-acclimated mice. These findings indicate that glucagon is a calorigenic hormone in mice and its effect is potentiated by cold acclimation possibly due to an activation of thermogenic mechanism(s) in brown adipose tissue.