Effects of fasting and refeeding on energetic metabolism of cold acclimated rats.
In rats acclimated at 5 degrees C or 28 degrees C (thermal neutrality), overnight fasting induced decreases in body and brown adipose tissue (BAT) weights and led to a larger decrease in resting metabolism (RM) in the 5 degrees C rats than in the 28 degrees C group. Refeeding significantly enhanced RM (diet-induced thermogenesis) in a greater extent in 5 degrees C than in 28 degrees C rats. This effect was inhibited by propranolol (beta adrenergic receptor antagonist) in 28 degrees C but was only halved in 5 degrees C rats. The capacity for nonshivering thermogenesis as determined by norepinephrine infusion was reduced by fasting only in 28 degrees C group; it remained unchanged in cold acclimated rats despite the large lipid utilization induced by fasting.
Bertin
R
R
Laboratoire d'Adaptation Energétique à l'Environnement, Ecole Pratique des Hautes Etudes, Paris, France.
De Marco
F
F
Portet
R
R
D000064:Acclimatization / Q000502:physiology*; D002001:Adipose Tissue, Brown / Q000502:physiology; D000818:Animals; D001833:Body Temperature Regulation / Q000502:physiology; D003080:Cold Temperature; D004435:Eating; D004734:Energy Metabolism / Q000502:physiology*; D005215:Fasting; D009638:Norepinephrine / Q000494:pharmacology; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000502:physiology
D009638:Norepinephrine