Radioligand Binding Studies of Adrenergic Receptors: New Insights into Molecular and Physiological Regulation

Abstract

The advent of direct radioligand binding studies has altered the entire complexion of the experimental approach to the study of adrenergic recep­ tors. The first successful direct binding studies of ,8-adrenergic receptors were reported in 1974 (1-3) and those of a.-adrenergic receptors only in 1976 (4-6). Nonetheless, the application of these methods over the past several years has led to rapid progress in a number of areas. In this article we review some of the highlights of this progress. It has not been our goal to be encyclopedic or all-encompassing. Rather, we have deliberately se­ lected several areas for more extensive coverage. These choices have been, obviously, subjective ones. In general we have focused on studies that provide new insights into factors that appear to regulate the function of the adrenergic receptors, either at a physiological or biochemical level. Only material related to a.and ,8-adrenergic receptors published through the end of 1978 has been systematically considered. Several radioligand antagonists have bee n widely used to study the ,8adrenergic receptors in a variety of tissue systems. These are (-) PH]