Article révisé par les pairs
Résumé : Pharmacological drugs activate cellular functions by binding to specific receptors. Experimental observations have shown that, in many systems, the drug effect is half-maximally elicited at drug concentrations far lower than those required for saturating half the receptors. In the case of the β-adrenergic system, such a discrepancy can be correlated with the efficacy of agonists in activating the adenylate cyclase. It is shown in this paper that, within the framework of the model describing the receptor-adenylate cyclase interaction, the experimentally observed discrepancy between binding and activation is a direct consequence of the structure of the system and is, in fact, an index of the drug efficacy.