MADOPAR-INDUCED DYSKINESIA IN 1-METHYL-4-PHENYL-1,2,3,6-TETRAHYDROPYRIDINE (MPTP) HEMIPARKINSONIAN MONKEY MODEL

Infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) into the right common carotid artery produced hemiparkinsonian syndrome on contralateral limbs in 5 rhesus monkeys. The hemiparkinsonian syndrome produced responded to madopar medication and the circling motion changed from toward the MPTP-treated side to away from the MPTP-treated side. Long term use of madopar developed a peak-dose dyskinesia of the face and limbs at the contralateral side. The toxic effect of MPTP was confirmed biochemically by reduction of nigrostriatal DA and histologically by degeneration of nigral neurons on the MPTP-treated side. It is concluded that this hemiparkinsonian monkey model will be of value in the elucidation of the neural mechanism underlying L-DOPA or DA agonists induced dyskinesia in Parkinson’s disease and in the search for newer methods of treatment which would produce less dyskinesia.