Selective D2 receptor stimulation induces dyskinesia in parkinsonian monkeys.
Stimulation of D1 striatal receptors has been proposed as the main mechanism mediating levodopa-induced dyskinesia in Parkinson's disease. We used (+)-PHNO, a selective D2 agonist, as the only treatment in 6 cynomolgus monkeys made parkinsonian by repeated 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine administration. All animals developed choreic dyskinesia after a mean treatment period of 12.8 days (range, 1-29). Administration of the D1 antagonist SCH-23390 1 hour before administration of (+)-PHNO did not change the dyskinesia. These results indicate that drug-induced dyskinesia in a primate model of Parkinson's disease is not solely induced by D1 receptor activation.
Luquin
M R
MR
Department of Neurology, University of Navarra, Medical School, Pamplona, Spain.
Laguna
J
J
Obeso
J A
JA
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D015259:Dopamine Agents; D004305:Dose-Response Relationship, Drug; D005260:Female; D008252:Macaca fascicularis; D008297:Male; D009069:Movement Disorders / Q000209:etiology*; D010078:Oxazines; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000150:complications*; D011954:Receptors, Dopamine / Q000502:physiology*; D017448:Receptors, Dopamine D2
D001552:Benzazepines; D015259:Dopamine Agents; D010078:Oxazines; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; C042631:naxagolide