The monoamine reuptake inhibitor BTS 74 398 fails to evoke established dyskinesia but does not synergise with levodopa in MPTP-treated primates.
Long-term treatment of Parkinson's disease (PD) with levodopa (L-dopa) induces dyskinesia that, once established, is provoked by each dose of L-dopa or a dopamine (DA) agonist. In contrast, monoamine reuptake inhibitors may reverse motor deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated primates without provoking established involuntary movements. We now examine whether the potent monoamine reuptake blocker BTS 74 398 induces established dyskinesia in MPTP-treated common marmosets primed previously with L-dopa and whether co-administration of BTS 74 398 with L-dopa potentiates motor behaviour and dyskinesia induced by acute L-dopa treatment. Administration of BTS 74 398 (2.5, 5.0, or 10.0 mg/kg, p.o.) in MPTP-treated common marmosets increased locomotor activity and reduced motor disability in a dose-related manner but did not provoke involuntary movements. BTS 74 398 (2.5, 5.0, or 10.0 mg/kg p.o.) co-administered with a threshold dose of L-dopa (2.5 mg/kg p.o.) did not evoke a motor response or induce dyskinesia. Similarly, concomitant administration of BTS 74 398 (5.0 mg/kg p.o.) with a submaximal L-dopa dose (12.5 mg/kg p.o.) did not potentiate the motor response produced by L-dopa alone and there was no alteration in the dyskinesia provoked by L-dopa challenge. BTS 74 398 reverses motor abnormalities in MPTP-treated marmosets without evoking established dyskinesia but no additive improvement occurs when administered in combination with L-dopa. The lack of synergy with L-dopa may suggest different sites of drug action.
Hansard
Matthew J
MJ
Neurodegenerative Disease Research Centre, Guy's, King's and St. Thomas' School of Biomedical Sciences, King's College, London, United Kingdom.
Smith
Lance A
LA
Jackson
Michael J
MJ
Cheetham
Sharon C
SC
Jenner
Peter
P
D000818:Animals; D000978:Antiparkinson Agents / Q000494:pharmacology*; D002144:Callithrix; D002230:Carbidopa / Q000494:pharmacology; D002722:Chlorobenzenes / Q000494:pharmacology*; D003503:Cyclobutanes / Q000494:pharmacology*; D004298:Dopamine / Q000502:physiology; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004409:Dyskinesia, Drug-Induced / Q000503:physiopathology*; D007980:Levodopa / Q000494:pharmacology*; D008124:Locomotion / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D009048:Motor Skills / Q000187:drug effects* / Q000502:physiology; D009460:Neurologic Examination / Q000187:drug effects; D020734:Parkinsonian Disorders / Q000503:physiopathology*; D004856:Postural Balance / Q000187:drug effects / Q000502:physiology; D013239:Stereotyped Behavior / Q000187:drug effects / Q000502:physiology
D000978:Antiparkinson Agents; C488846:BTS 74 398; D002722:Chlorobenzenes; D003503:Cyclobutanes; D018765:Dopamine Uptake Inhibitors; D007980:Levodopa; D002230:Carbidopa; D004298:Dopamine