[3H]Ketanserin labels 5-HT2 receptors and α1-adrenoceptors in human and pig brain membranes

Abstract

The binding characteristics of [3H]ketanserin (a reported selective radioligand for serotonin 5-HT2 receptors) and [125I]BE 2254 (which labels selectively α1-adrenoceptors) were characterized in brain frontal cortex membranes of pig and man. Saturation experiments indicated that both radioligands label apparently a homogeneous class of binding sites in human and pig fontal cortex membranes. Competition experiments with [125I]BE 2254 using 17 agonists and antagonists showed monophasic and steep curves in human and pig frontal cortex membranes. The pharmacological profile of these sites is typical of α1-adrenoceptors. In competition experiments with [3H]ketanserin, most of the tested compounds..