| In Vitro | In vitro activity: Pardoprunox (formerly known as SLV-308, DU-126891 or SME-308) is novel & potent dopamine D2/5-HT1A receptor agonist that has the potential for the treatment of Parkinson's disease. Pardoprunox acts by binding to dopamine D(2), D(3), and D(4) receptors and 5-HT(1) (A) receptors and is a partial agonist at dopamine D(2) and D(3) receptors and a full agonist at serotonin 5-HT(1) (A) receptors. At cloned human dopamine D(2,L) receptors, SLV308 acted as a potent but partial D(2) receptor agonist (pEC(50) = 8.0 and pA(2) = 8.4) with an efficacy of 50% on forskolin stimulated cAMP accumulation. At human recombinant dopamine D(3) receptors, SLV308 acted as a partial agonist in the induction of [(35)S]GTPgammaS binding (intrinsic activity of 67%; pEC(50) = 9.2) and antagonized the dopamine induction of [(35)S]GTPgammaS binding (pA(2) = 9.0). SLV308 acted as a full 5-HT(1) (A) receptor agonist on forskolin induced cAMP accumulation at cloned human 5-HT(1) (A) receptors but with low potency (pEC(50) = 6.3).
Kinase Assay: Pardoprunox also binds to D4 (pKi = 7.8), α1-adrenergic (pKi = 7.8), α2-adrenergic (pKi = 7.4), and 5-HT7 receptors (pKi = 7.2) with lower affinity. Pardoprunox acts as a potent but partial D(2) receptor agonist (pEC50 = 8.0 and pA2 = 8.4) with an efficacy of 50% on forskolin stimulated cAMP accumulation. At human recombinant dopamine D3 receptors, Pardoprunox acts as a partial agonist in the induction of [35S]GTPgammaS binding (intrinsic activity of 67%; pEC(50) = 9.2) and antagonized the dopamine induction of [35S]GTPgammaS binding (pA2 = 9.0). Pardoprunox acts as a full 5-HT1A receptor agonist on forskolin induced cAMP accumulation at cloned human 5-HT1A receptors but with low potency (pEC50 = 6.3)
Cell Assay: |
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| In Vivo | Pardoprunox induces contralateral turning behaviour in rats with unilateral 6-hydroxydopamine-induced lesions of the substantia nigra pars compacta (SNpc) (MED=0.03mg/kg; po). In MPTP-treated common marmosets, Pardoprunox dose-dependently increases locomotor activity (MED=0.03mg/kg; po) and decreases motor disability (MED=0.03mg/kg; po). In contrast Pardoprunox attenuated novelty-induced locomotor activity (MED=0.01mg/kg; po), (+)-amphetamine-induced hyperlocomotion (MED=0.3mg/kg; po) and apomorphine-induced climbing (MED=0.6mg/kg; po) in rodents. Pardoprunox also induces 5-HT1A receptor-mediated behaviours, including flat body posture and lower lip retraction (MED=0.3mg/kg; po). Collectively, these findings demonstrate that Pardoprunox possesses dopamine D2/3 partial agonist effects, 5-HT1A agonist effects and reduces parkinsonism in animal models. functional D2 receptor partial agonist activity and is effective in experimental models predictive of efficacy in PD |
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