Effect of clonidine and atropine on rest tremor in the MPTP monkey model of parkinsonism.
The purported alpha 2-adrenergic agonist clonidine was found to inhibit rest tremor at doses of 0.023-0.1 mg/kg in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine monkey model of parkinsonism. The effect was dose dependent, but sedation and reduced mobility were observed. Atropine at doses of 0.1-1 mg/kg also reduced tremor in a dose-dependent fashion, but side-effects in the form of agitation, dilated pupils, and dry mouth were seen. When the two drugs were combined, however, we saw a significant potentiation of the antitremor effect. We could even abolish tremor with doses of atropine and clonidine that by themselves were without effect. The side-effects were almost eliminated by the combination.
Gomez-Mancilla
B
B
Centre de Recherche en Neurobiologie, Hôpital de l'Enfant-Jésus, Québec, Canada.
Boucher
R
R
Bédard
P J
PJ
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D000818:Animals; D001285:Atropine / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D003000:Clonidine / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D004195:Disease Models, Animal; D004576:Electromyography; D005260:Female; D008252:Macaca fascicularis; D009132:Muscles / Q000187:drug effects; D010302:Parkinson Disease, Secondary / Q000188:drug therapy / Q000503:physiopathology*; D013997:Time Factors; D014202:Tremor / Q000188:drug therapy* / Q000503:physiopathology
D001285:Atropine; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D003000:Clonidine