title: A model for agonists acting directly as well as indirectly.
abstract: A theoretical model is presented to describe the receptor interaction of a drug which possesses indirect as well as direct pharmacological action. Sets of theoretical log concentration-effect curves predicted by this model are presented. The model predicts that the shape of the log concentration-effect curves may be sigmoid (S-shaped), biphasic (bell-shaped) or composed of a combination of two sigmoid curves, joined together by a plateau. The theoretical predictions are comparable with the results obtained from an experimental study.
mesh_terms: D000818:Animals; D066298:In Vitro Techniques; D008297:Male; D008433:Mathematics; D008954:Models, Biological; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D051381:Rats; D011955:Receptors, Drug / Q000187:drug effects*; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D011955:Receptors, Drug