Factors influencing the acute effect of food on oxygen consumption in the rat.
The rise in resting oxygen consumption (VO2) during the 2-3 h following intragastric feeding (50 kJ [12 kcal]) was significantly greater in hyperphagic cafeteria-fed rats and hyperthyroid rats, but was markedly reduced in 3-day fasted and genetically-obese Zucker rats, compared to their respective stock-fed controls. In control and hyperthyroid animals this response was almost completely abolished by administration of propranolol. In another group of rats, resting VO/ was elevated by 8 per cent after 12 h of cafeteria feeding and was maximally increased by 20 per cent after 2.5 days on the diet. In rats previously cold-adapted (15 days at 5 degrees C) the maximal response (20 per cent) to cafeteria feeding was seen after only 12 h on the diet. These results suggest that the acute thermic response to food involves a sympathetic activation of thermogenesis, similar to that induced by chromic hyperphagia and cold-exposure, and can be influenced by genetic background plane of nutrition and thyroidal status.
D000222:Adaptation, Physiological; D000818:Animals; D003080:Cold Temperature; D004435:Eating; D004734:Energy Metabolism; D005247:Feeding Behavior / Q000502:physiology; D008297:Male; D009765:Obesity / Q000503:physiopathology; D010101:Oxygen Consumption / Q000187:drug effects; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011924:Rats, Zucker; D013997:Time Factors; D014284:Triiodothyronine / Q000494:pharmacology
D014284:Triiodothyronine; D011433:Propranolol