title: Dopamine D3 receptor as a therapeutic target for antipsychotic and antiparkinsonian drugs.
abstract: The cloning of the gene for the D3 receptor and subsequent identification of its distribution in brain and pharmacology allowed for serious consideration of the possibility that it might be a target for drugs used to treat schizophrenia and Parkinson's disease (PD). That is because it is highly expressed in limbic regions of the brain, exhibits low expression in motor divisions, and has pharmacologic similarity to the D2 receptor. Thus, antipsychotics that were presumed to block D2 receptors also had high affinity for the D3 receptor. Dopamine agonists used to treat the clinical symptoms of PD also have high affinity for the D3 receptor, and two D3 receptor-preferring agonists were found to be effective for treatment of PD. Many compounds achieving high potency and selectivity are now available, but few have reached clinical testing. Recent findings with respect to the anatomy of this receptor in human brain, altered expression in schizophrenia and PD, and biological models to study its function support the proposal that it is a target for development of drugs to alleviate symptoms in neuropsychiatric and neurologic disorders. Because of distinct aspects of regulation of the D3 receptor, it represents a unique target for therapeutic intervention in schizophrenia without high potential for unintended side effects such as tardive dyskinesia. It may also be that D3 receptor agonists can provide neuroprotective effects in PD and can modify clinical symptoms that D2 receptor-preferring agonists cannot provide.
authors.affiliation: Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 10515 West Santa Fe Drive, Sun City, AZ 85351, USA. Jeff.Joyce@sunhealth.org
authors.forename: J N
authors.initials: JN
authors.lastname: Joyce
mesh_terms: D000818:Animals; D000978:Antiparkinson Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001921:Brain / Q000187:drug effects* / Q000502:physiology; D016503:Drug Delivery Systems; D006801:Humans; D010300:Parkinson Disease / Q000235:genetics; D017448:Receptors, Dopamine D2 / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D050637:Receptors, Dopamine D3; D012559:Schizophrenia / Q000235:genetics
chemical_list: D000978:Antiparkinson Agents; D014150:Antipsychotic Agents; C493593:DRD3 protein, human; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3