Recent advances in knowledge about beta-adrenergic receptors: application to clinical cardiology.

The properties of beta-adrenergic receptors in the cardiovascular system have been studied in the past by two experimental approaches, which can be termed pharmacologic and biochemical. In the pharmacologic approach, the nature of a drug interaction with receptors is deduced from alterations in the physiologic properties of the tissue caused by administration of various concentrations of the drug. Many important concepts about beta-adrenergic receptors have come from such indirect pharmacologic studies. The biochemical approach directly assesses the interaction of drugs with beta-adrenergic receptors by studying the binding of radiolabeled antagonists and agonists with the receptor. This relatively new approach has provided a large amount of new information regarding the intrinsic properties of beta-adrenergic receptors and modification of these properties by physiologic stresses, administration of drugs and disease states. The biochemical approach has also been applied recently to the study of beta-adrenergic receptors in human beings. In the future, substantial clinically relevant new information regarding the nature of beta-adrenergic receptors in physiologic and pathologic conditions should result from application of a combination of the biochemical and physiologic approaches to studies in human beings.