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

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 x 10(-9)M 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 Kd (dissociation constant) for the high affinity site can be competed for with classical adrenergic ligands, is reversible and does not display cooperative interactions.