Evidence for cold-induced but not for diet-induced thermogenesis in adult dogs.
Rats often exhibit diet-induced thermogenesis when overfed, which has been linked to activation of the sympathetic nervous system. In the present study, adult dogs housed at 22 degrees C were fed 150 or 200% of maintenance intake for 4 wk or 6 d, respectively. The overfed dogs gained body weight without an increase in 24-h energy expenditure or activation of the sympathetic nervous system, as assessed by norepinephrine release to plasma and urinary norepinephrine excretion. Acclimation to cold (3 degrees C for 4 wk) increased energy expenditure 38%, norepinephrine apparent release to plasma 64% and urinary norepinephrine excretion 42%. This cold-induced thermogenesis did not, however, switch to diet-induced thermogenesis when dogs were removed from the cold and fed 150% of maintenance. In conclusion, no evidence was found for diet-induced thermogenesis in adult dogs.
D000818:Animals; D001833:Body Temperature Regulation; D002153:Calorimetry, Indirect; D003080:Cold Temperature; D004032:Diet; D004285:Dogs; D004734:Energy Metabolism; D004837:Epinephrine / Q000652:urine; D005260:Female; D006799:Housing, Animal; D009638:Norepinephrine / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000502:physiology; D013696:Temperature; D013997:Time Factors
D009638:Norepinephrine; D004837:Epinephrine