Dobutamine as selective β1-adrenoceptor agonist in in vivo studies on human thermogenesis and lipid utilization

Abstract

The use of dobutamine as selective β1-adrenoceptor agonist in in vivo studies on human thermogenesis and lipid utilization was investigated in 20 men. At 2.5, 5, and 10 μg ⋅ kg−1 ⋅ min−1, dobutamine induced significant increases in energy expenditure, lipid oxidation, and lipolysis. The β1-adrenoceptor antagonist atenolol (bolus: 42.5 μg/kg, infusion: 1.02 μg ⋅ kg−1 ⋅ min−1) blocked all dobutamine-induced effects on thermogenesis and lipid utilization. All parameters remained at levels comparable to those during saline infusion. The dose of atenolol used did not inhibit β2-adrenoceptor-specific changes in energy expenditure, lipid oxidation, and lipolysis during salbutamol infusion (85 ng ⋅ kg−1 ⋅ min−1). This indicates that atenolol was specific for β1-adrenoceptors and did not camouflage concomitant β2-adrenoceptor stimulation during dobutamine infusion. Therefore, we conclude that dobutamine can be used as a selective β1-adrenoceptor agonist at dosages ≤10 μg ⋅ kg−1 ⋅ min−1in in vivo studies on human thermogenesis and lipid utilization.