Characterization of beta-adrenoceptor subtypes in rabbit mononuclear leukocytes

Computer analysis of [125I]iodocyanopindolol competition studies using the relatively selective beta 1-adrenoceptor antagonist, ICI 89406, and the beta 2-selective antagonist, ICI 118551, on rabbit mononuclear leukocyte plasmalemmal preparations favored a two-site model indicating that both beta 1- and beta 2-adrenoceptor subtypes were present in approximately equal numbers. In contrast, similar studies performed on rabbit cardiac sarcolemma favored a one site model consistent with the presence of beta 1-adrenoceptors. Consequently, rabbit mononuclear leukocytes may provide a useful model for studying selective modulatory mechanisms of beta 1- and beta 2-adrenoceptors.