β3 Receptors: Role in cardiometabolic disorders

Abstract

Pharmacological and molecular approaches have shown that an atypical β-adrenoceptor (AR), called β3-AR, that is distinct from β1-ARs and β2-ARs, exists in some tissues in heterogeneous populations such as β3a-ARs and β3b-ARs. β3-ARs belong to a superfamily of receptors linked to guanine nucleotide binding proteins (G proteins). The β3-AR gene contains two introns whereas the β1-AR and β2-AR genes are intronless, leading to splice variants. β3-ARs can couple to Gi and Gs and they are reported to be present in brown adipose tissue, vasculature, the heart, among other tissues. β3-ARs cause vasodilation of microvessels in the islets of Langerhans and may participate in the pathogenesis of cardiac failure, during which modification of β1-AR and β2-AR expression occurs. The development of β3-AR agonists has led to the elaboration of promising new drugs, including antiobesity and antidiabetic drugs. This article reviews the various pharmacological actions of β3-ARs and their clinical implications for diabetes and cardiovascular diseases. © 2011, SAGE Publications. All rights reserved.