title: Influence of beta-adrenergic blockade on glucose-induced thermogenesis in man.
abstract: The role of beta-adrenergically mediated sympathetic nervous activity in the regulation of glucose-induced thermogenesis was examined in healthy male subjects. Respiratory gas exchange was measured continuously, using the ventilated hood technique, under conditions of hyperinsulinemia and hyperglycemia (glucose clamp technique, insulin infusion 1 mU/kg per min, glucose levels 125 mg/dl above basal) before and after beta-adrenergic blockade (i.v. propranolol, 3-mg bolus plus 0.1 mg/min for 2 h). After 2 h of insulin and glucose infusion in series 1, glucose uptake had increased to 23.5 +/- 2.3 mg/kg per min and insulin concentration to 199 +/- 21 microU/ml. Simultaneously, the energy expenditure had risen by 0.39 +/- 0.05 kcal/min above basal. After propranolol administration, glucose uptake did not change, while energy expenditure fell significantly, to a level 0.28 +/- 0.04 kcal/min above basal. The glucose-induced thermogenesis (GIT) was 6.5 +/- 0.3% before and 4.6 +/- 0.5% (P less than 0.02) after propranolol. In series 2, insulin and glucose infusion was continued for 4 h without propranolol administration. Glucose uptake rose (+12%) and insulin levels increased (+40%) between the 2nd and 4th h but energy expenditure and GIT remained unchanged. Subjects in series 3 received saline infusion alone for 3 h, at which time propranolol administration as in series 1 was added during a further 2-h period. No changes in energy expenditure were seen during saline or propranolol infusion. These data demonstrate the presence of a beta-adrenergically mediated sympathetic nervous component in glucose-induced thermogenesis in healthy human subjects. This factor may be of importance in the regulation of normal body weight in man.
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000328:Adult; D001481:Basal Metabolism / Q000187:drug effects; D001833:Body Temperature Regulation / Q000187:drug effects*; D004734:Energy Metabolism / Q000187:drug effects; D005947:Glucose / Q000008:administration & dosage* / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism; D006946:Hyperinsulinism / Q000378:metabolism; D007328:Insulin / Q000097:blood; D008297:Male; D011433:Propranolol / Q000008:administration & dosage*
chemical_list: D000319:Adrenergic beta-Antagonists; D007328:Insulin; D011433:Propranolol; D005947:Glucose