Beta-adrenergic receptors are different in subpopulations of human circulating lymphocytes.

Mononuclear leucocytes (MNL) were isolated from blood of 11 healthy blood donors. Lymphocyte subsets were sorted in a Cytofluorograf after direct (B cells) or indirect immunofluorescence labeling with monoclonal antibodies directed against the phenotypes of T-, T helper (Th)- and T suppressor (Ts) cells. The sorted cells were incubated with (+/-)125iodocyanopindolol ([125I]CYP) for the determination of beta-adrenergic receptors. Beta-adrenergic receptors on B cells were increased two-fold (3700 sites/cell, p less than 0.004) and had a lower affinity (dissociation constant KD 40pM, p less than 0.03) when compared with T cells (1400 sites/cell, KD 17pM). Receptors on Th- and Ts cells showed a similar binding capacity, but Ts cells had a slightly higher [125I]CYP binding affinity (KD 13 pM) than Th cells (KD 27 pM, p less than 0.02). The different densities and affinities of beta-adrenergic receptors in human lymphocyte subsets, as assessed by antagonist binding should be considered in the interpretation of receptor alterations of unfractionated MNL, which may occur simultaneously to changes of the blood leucocyte distribution.