Salbutamol antagonizes insulin- and sodium mercaptoacetate-induced but not 2-deoxy-D-glucose-induced hyperphagia.
The role of beta-adrenoreceptors in modulating feeding in glucoprivation- and lipoprivation-induced hyperphagias was studied in rats by measuring the efficacy of the selective beta2-adrenoreceptor agonist salbutamol to antagonize the hyperphagic response induced by injection of 2-deoxy-D-glucose (2-DG), insulin, or sodium mercaptoacetate (MA). 2-DG and insulin are blockers of glucose utilization, and their administration stimulates receptor cells that are selectively sensitive to central glucose availability. MA stimulates feeding in rats maintained on a fat-supplemented diet, by blocking fatty acid oxidation at different levels in the metabolic pathway. We found that salbutamol dose-dependently antagonized both the insulin- and MA-induced hyperphagia, with reductions in food intake up to 100% compared with rats treated with insulin or MA alone. On the contrary, salbutamol, even at the highest dose (15 mg/kg, IP), was completely ineffective against 2-DG-induced hyperphagia. The present results support the previously proposed notion that there are different neuronal or humoral circuits underlying the hyperphagic responses to the metabolic stimuli induced by glucoprivation (i.e., 2-DG and insulin administration), and they extend our knowledge on the effects of salbutamol on glucoprivic and lipoprivic control of feeding.
Nisoli
E
E
Department of Pharmacology, Chemotherapy and Medical Toxicology, School of Medicine, University of Milan, Italy.
Garosi
V
V
Blundell
J E
JE
Carruba
M O
MO
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000420:Albuterol / Q000494:pharmacology*; D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology*; D003847:Deoxyglucose / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects*; D005947:Glucose / Q000502:physiology; D007004:Hypoglycemic Agents / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D007329:Insulin Antagonists / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013864:Thioglycolates / Q000037:antagonists & inhibitors* / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D000963:Antimetabolites; D007004:Hypoglycemic Agents; D007328:Insulin; D007329:Insulin Antagonists; D013864:Thioglycolates; C017487:2-mercaptoacetate; D003847:Deoxyglucose; D005947:Glucose; D000420:Albuterol