Metabolic response to various β-adrenoceptor agonists in β _3-adrenoceptor knockout mice: Evidence for a new β-adrenergic receptor in brown adipose tissue

摘要

Theβ_3-adrenoceptor plays an important role in the adrenergic response of brown and white adipose tissues (BAT and WAT). In this study, in vitro metabolic responses to β-adrenoceptor stimulation were compared in adipose tissues ofβ_3-adrenoceptor knockout and wild type mice. The measured parameters were BAT fragment oxygen uptake (MO_2) and isolated white adipocyte lipolysis. In BAT of wild type mice(-)-norepinephrine maximally stimulated MO_2 4.1±0.8 fold. Similar Maximal stimulations were obtained with β_1-, β_2- orβ_3-adrenoceptor selective agonists (dobutamine 5.1±0.3, terbutaline 5.3±0.3 and CL 316,243 4.8±0.9 fold, respectively); in BAT ofβ_3-adrenoceptor knockout mice, the β_1- and β_2-responses were fully conserved.