Selective D2 receptor stimulation induces dyskinesia in parkinsonian monkeys
Luquin M.R., Laguna J., Obeso J.A.
Department of Neurology, University of Navarra, Medical School, Pamplona, Spain
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.
CITATION Ann Neurol. 1992 May;31(5):551-4