0000000000323805
AUTHOR
R. K. B. Pearce
Alterations in striatal neuropeptide mRNA produced by repeated administration of L-DOPA, ropinirole or bromocriptine correlate with dyskinesia induction in MPTP-treated common marmosets
Chronic administration of L-DOPA to MPTP-treated common marmosets induces marked dyskinesia while repeated administration of equivalent antiparkisonian doses of ropinirole and bromocriptine produces only mild involuntary movements. The occurrence of dyskinesia has been associated with an altered balance between the direct and indirect striatal output pathways. Using in situ hybridisation histochemistry, we now compare the effects of these drug treatments on striatal preproenkephalin-A (PPE-A) and adenosine A(2a) receptor mRNA expression as markers of the indirect pathway and striatal preprotachykinin (PPT) mRNA and preproenkephalin-B (PPE-B, prodynorphin) mRNA expression as markers of the d…
Both Short- and Long-Acting D-1/D-2 Dopamine Agonists Induce Less Dyskinesia than l-DOPA in the MPTP-Lesioned Common Marmoset (Callithrix jacchus)
Abstract The current concept of dyskinesia is that pulsatile stimulation of D-1 or D-2 receptors by l -DOPA or short-acting dopamine agonists is more likely to induce dyskinesia compared to long-acting drugs producing more continuous receptor stimulation. We now investigate the ability of two mixed D-1/D-2 agonists, namely pergolide (long-acting) and apomorphine (short-acting), to induce dyskinesia in drug-naive MPTP-lesioned primates, compared to l -DOPA. Adult common marmosets ( Callithrix jacchus ) were lesioned with MPTP (2 mg/kg/day sc for 5 days) and subsequently treated with equieffective antiparkinsonian doses of l -DOPA, apomorphine, or pergolide for 28 days. l -DOPA, apomorphine, …