CGP 20712 dihydrochloride is a potent and selective antagonist of β1-adrenoceptor with IC50 value of 0.7 nM [1].
β1-adrenoceptor is a G-protein coupled receptor and mediates uncoupling protein-1 (UCP1) gene expression induced by norepinephrine (NE) [2].
CGP 20712 dihydrochloride is a potent and selective β1-adrenoceptor antagonist. In neocortical membranes, CGP 20712 A exhibited affinity for β1-adrenoceptor and β2-adrenoceptor with IC50 values of 0.7 and 6700 nM, respectively [1]. In brown adipocytes, CGP-20712A significantly inhibited UCP1 gene expression induced by NE. However, CGP-20712A had no effect on lipolysis. These results suggested that β1-adrenoceptor mediated UCP1 gene expression [2]. In ventricular membranes from rats, CGP 20712A (300 nM) completely occupied its high-affinity binding sites. In ventricular myocytes isolated from rats, CGP 20712A (10, 100, 1000 nM) didn’t cause the activation of adenylate cyclase mediated by β2-adrenoceptors, which suggested that β2-adrenoceptors were not present on rat ventricular myocytes [3]. In adult rat cardiac myocytes, CGP 20712A inhibited β1-AR-stimulated apoptosis, which was mediated by a cAMP-dependent mechanism [4].
References:
[1]. Dooley DJ, Bittiger H, Reymann NC. CGP 20712 A: a useful tool for quantitating beta 1- and beta 2-adrenoceptors. Eur J Pharmacol, 1986, 130(1-2): 137-139.
[2]. Chaudhry A, Granneman JG. Differential regulation of functional responses by beta-adrenergic receptor subtypes in brown adipocytes. Am J Physiol, 1999, 277(1 Pt 2): R147-153.
[3]. Kitagawa Y, Adachi-Akahane S, Nagao T. Determination of beta-adrenoceptor subtype on rat isolated ventricular myocytes by use of highly selective beta-antagonists. Br J Pharmacol. 1995, 116(1): 1635-1643.
[4]. Communal C, Singh K, Sawyer DB, et al. Opposing effects of beta(1)- and beta(2)-adrenergic receptors on cardiac myocyte apoptosis : role of a pertussis toxin-sensitive G protein. Circulation, 1999, 100(22): 2210-2212.