title: Dopamine receptors, motor responses, and dopaminergic agonists.
abstract: Dopamine receptors are widely distributed within the central nervous system with its highest expression in the striatum. Two different families of dopamine receptors have been identified. The D₁ family comprises D₁ and D5 receptors, whereas D₂, D₃, and D₄ receptors form the D₂ family. These 2 families mediate different behavior patterns that are linked to activation of specific transduction pathways. The functional relevance of dopamine receptors derives from the reduced dopamine content found in the striatum of Parkinson disease (PD) patients and the ability of dopamine and dopamine receptors to reverse the motor deficits exhibited by PD patients. During the last 2 decades dopamine receptor agonists have been used either in de novo PD patients to prevent the appearance of dyskinesias or in PD patients with motor fluctuations to reduce the number of daily "off" hours. It seems that all dopamine receptors agonists produce similar motor responses and adverse effects, but data comparing their effectiveness in the treatment of PD are not available. In this article we summarize the main characteristics of dopamine receptors, their structure, their signaling pathways, and the responses mediated by their independent activation. Here is also described the therapeutic value of the different dopamine receptor agonists in the treatment of PD.
authors: Department of Neurology and Neurosurgery, Clínica Universidad de Navarra, Avenida de Pio, Pamplona, Spain. rluquin@unav.es
authors: Ma Rosario
authors: MR
authors: Luquin-Piudo
authors: Pilar
authors: P
authors: Sanz
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000978:Antiparkinson Agents / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use*; D016718:Arachidonic Acid / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D018491:Dopamine Agonists / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use*; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D009043:Motor Activity / Q000187:drug effects*; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011954:Receptors, Dopamine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000978:Antiparkinson Agents; D015220:Calcium Channels; D018491:Dopamine Agonists; D020033:Protein Isoforms; D011954:Receptors, Dopamine; D016718:Arachidonic Acid; D007980:Levodopa; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D004298:Dopamine