Characteristics of Adrenergic Binding Sites Associated with Murine Lymphocytes Isolated from Spleen

Abstract

Beta-adrenergic binding sites have been identified and characterized on murine lymphocytes. The binding sites are of two distinct classes, a high affinity class which has an apparent dissociation constant of about 1 × 10⁻⁹M and numbers about 500 sites per cell, and a higher capacity binding class that appears to be more characteristic of a non-specific binding site. The binding of a beta-adrenergic radioligand at concentrations about equal to the K_d (dissociation constant) for the high affinity site can be competed for with classical adrenergic ligands, is reversible and does not display cooperative interactions.