The effect of the alpha 2-adrenoceptor agonist, guanfacin, on energy expenditure, intake and deposition in rats.
The effect of guanfacin on the energy expenditure, food intake and body composition of female Wistar rats at maintenance was studied. Rats on a restricted food intake (about 75% of ad libitum), treated for 6 days with twice-daily injections of guanfacin.HCl (0.5 mg/kg) showed large reductions in energy expenditure (30%, p < 0.001) compared to control animals but no significant differences in liveweight gain, dry mass gain, or gains in total body energy content, protein, fat and ash. The treated group had a lower intake of metabolizable energy (9%, p = 0.01) partially due to a lower intake of food. However, this lower intake of energy did not fully account for the lowered energy expenditure in the treated animals. The unaccounted lowered energy expenditure was not due to changes in the diurnal pattern of energy expenditure since continuous indirect calorimetry with rats fed ad libitum, over 3 days, showed that twice-daily injections of guanfacin (0.5 mg/kg per injection) achieved a sustained decrease in energy expenditure. The lack of an increased growth rate of rats treated with guanfacin was attributed to behavioural changes; to a decreased food intake and to other, unknown, factors related to energy expenditure.
Gazzola
C
C
Queensland Department of Primary Industries, Tropical Beef Centre, Australia.
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001823:Body Composition / Q000187:drug effects*; D001827:Body Height / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D004435:Eating / Q000187:drug effects*; D004734:Energy Metabolism / Q000187:drug effects*; D005260:Female; D016316:Guanfacine / Q000008:administration & dosage / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
D000316:Adrenergic alpha-Agonists; D016316:Guanfacine