Receptor discrimination and control of agonist-antagonist binding. Tallarida, Ronald J. Temple University School of Medicine, Philadelphia, PA 19140
APStracts 2:0095E, 1995.
The law of mass action is the common model for the interaction of agonist and antagonist compounds with cellular receptors. Parameters of the interaction, obtained from both functional and radioligand binding studies, allow discrimination and sub-typing of receptors and aid in understanding specific mechanisms . This article reviews the theory and associated mathematical models and graphical transformations of data that underlie the determination of receptor parameters. The main theory assumes that agonist and antagonist compounds bind to cells that have a fixed number of receptors and provides the framework for obtaining drug-receptor parameters from data and their graphical transformations. Conditions that produce a change in receptor number, a newer concept in pharmacology, can have an important effect on the parameter values derived in the usual way. This review concludes with a discussion of the quantitative study of receptor-mediated feedback control of endogenous ligands, a very new topic with potentially important implications for understanding antagonist effectiveness, loss of control and chaos in regulated mass-action binding.

Received 6 October 1994; accepted in final form 20 March 1995.
APS Manuscript Number E415-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on  2 May 1995.