title: Recent advances in drug action and therapeutics: relevance of novel concepts in G-protein-coupled receptor and signal transduction pharmacology.
abstract: OBJECTIVE
  During especially the past two decades many discoveries in biological sciences, and in particular at the molecular and genetic level, have greatly impacted on our knowledge and understanding of drug action and have helped to develop new drugs and therapeutic strategies. Furthermore, many exciting new drugs acting via novel pharmacological mechanisms are expected to be in clinical use in the not too distant future.
  In this educational review, these concepts are explained and their relevance illustrated by examples of drugs used commonly in the clinical setting, with special reference to the pharmacology of G-protein-coupled receptors. The review also addresses the basic theoretical concepts of full and partial agonism, neutral antagonism, inverse agonism and protean and ligand-selective agonism, and the relevance of these concepts in current rational drug therapy. Moreover, the mechanisms whereby receptor signalling (and eventually response to drugs) is fine-tuned, such as receptor promiscuity, agonist-directed trafficking of receptor signalling, receptor trafficking, receptor 'cross-talk' and regulators of G-protein signalling (RGSs) are discussed, from theory to proposed therapeutic implications.
  
  
  CONCLUSIONS
  It is concluded that the understanding of molecular receptor and signal transduction pharmacology enables clinicians to improve their effective implementation of current and future pharmacotherapy, ultimately enhancing the quality of life of their patients.
authors.affiliation: Division of Pharmacology, School of Pharmacy, Potchefstroom University for CHE, Potchefstroom, South Africa. fklcbb@puk.ac.za
authors.forename: C B
authors.initials: CB
authors.lastname: Brink
authors.forename: B H
authors.initials: BH
authors.lastname: Harvey
authors.forename: J
authors.initials: J
authors.lastname: Bodenstein
authors.forename: D P
authors.initials: DP
authors.lastname: Venter
authors.forename: D W
authors.initials: DW
authors.lastname: Oliver
mesh_terms: D002450:Cell Communication / Q000502:physiology; D019204:GTP-Binding Proteins / Q000502:physiology*; D017629:Gap Junctions / Q000502:physiology; D004364:Pharmaceutical Preparations; D043562:Receptors, G-Protein-Coupled / Q000819:agonists / Q000502:physiology*
chemical_list: D004364:Pharmaceutical Preparations; D043562:Receptors, G-Protein-Coupled; D019204:GTP-Binding Proteins