Modulation in vivo of β-adrenergic-receptor subtypes in rat brown adipose tissue by the thermogenic agonist Ro 16-8714

Abstract

The number of β3-adrenergic receptors (AR) in plasma membranes from interscapular brown adipose tissue (IBAT) was decreased by 62% in lean Zucker rats treated with the thermogenic β-adrenergic agonist Ro 16-8714 as compared with controls after 72 h of treatment. The loss of β3-AR number was preceded by a 93%, decrease in the steady-state level of AR mRNA at 30 h. Similar results were obtained in obese (fa/fa) Zucker rats. Ro 16-8714 had no effect on the number of β1- and β2 ARs in IBAT. This is the first report to demonstrate that the β3-AR in IBAT can be specifically down-regulated in vivo by exposure to a thermogenic agonist.