title: Receptors and dormant receptors--messengers and opportunistic ligands.
abstract: On the basis of the question what came first, the messenger or its specific receptor, the relation between the receptor concept and the messenger concept is discussed. Special attention is paid to opportunistic ligands that serve as messenger molecules and to dormant receptors, receptor-like proteins of unknown function. It is concluded that there is no receptor without a messenger and no messenger without a receptor.
authors.forename: E J
authors.initials: EJ
authors.lastname: Ariëns
mesh_terms: D000818:Animals; D006801:Humans; D008024:Ligands; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015290:Second Messenger Systems / Q000502:physiology*
chemical_list: D008024:Ligands; D011956:Receptors, Cell Surface