title: Influence of thyroid hormone on diet-induced thermogenesis in the rat.
abstract: Energy balance and brown adipose tissue (BAT) metabolism were studied in rats maintained on stock or 'cafeteria' diet, and injected with either saline or triiodothyronine (T3, 10 micrograms/100 g b.wt./d) for 14 d. Cafeteria-fed rats showed large increases in metabolizable energy intake, energy expenditure and BAT mass, Na+, K+-ATpase activity and mitochondrial GDP binding. In stock fed rats, T3 also stimulated energy intake, metabolic rate and BAT mass and Na+, K+-ATPase activity, but did not affect GDP binding. Hyperthyroidism potentiated the effects of cafeteria feeding on energy expenditure and BAT mass, but BAT Na+, K+-ATPase activity was only slightly higher than that of the euthyroid cafeteria rats, and GDP binding was similar for both groups. These results confirm the involvement of BAT in diet-induced thermogenesis and show that this is potentiated by hyperthyroidism. The data also suggest that thyroid thermogenesis may result, at least partly, from stimulation of BAT.
mesh_terms: D002001:Adipose Tissue, Brown / Q000033:anatomy & histology / Q000378:metabolism; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D004032:Diet; D004734:Energy Metabolism / Q000187:drug effects*; D006153:Guanosine Diphosphate / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014284:Triiodothyronine / Q000494:pharmacology*
chemical_list: D014284:Triiodothyronine; D006153:Guanosine Diphosphate; D000254:Sodium-Potassium-Exchanging ATPase