title: Indirectly acting agonists. A model for the functional interaction of released endogenous double agonists.
abstract: A theoretical model is presented to describe the functional interaction of an endogenous double agonist released by an indirectly acting agonist. The model takes into account the functional interaction of a released double (dualistic) agonist and describes both functional synergism and antagonism. It was shown that receptor density plays an important role in determining the profiles of concentration-effect curves and that it is necessary that the model should incorporate a parameter which describes receptor density. The model predicted that the shape of the concentration-effect curves may be sigmoid or bell-shaped. The theoretical predictions are comparable with experimental results.
authors.affiliation: Department of Pharmacology, Potchefstroom University for C.H.E., Republic of South Africa.
authors.forename: D P
authors.initials: DP
authors.lastname: Venter
mesh_terms: D000818:Animals; D004347:Drug Interactions; D004357:Drug Synergism; D007700:Kinetics; D008297:Male; D008432:Mathematical Computing; D008954:Models, Biological; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000502:physiology*; D014439:Tyramine / Q000494:pharmacology; D014649:Vas Deferens / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D011956:Receptors, Cell Surface; D014439:Tyramine