(S)-Pramipexole-d₅is intended for use as an internal standard for the quantification of (S)-pramipexole by GC- or LC-MS. (S)-Pramipexole is a dopamine D_2S, D_2L, D₃, and D₄receptor agonist (EC₅₀s = 426.58, 338.84, 2.24, and 128.82 nM, respectively, in a [³⁵S]GTPγS binding assay).¹It is also a partial agonist of α_2A-adrenergic receptors (α_2A-ARs; EC₅₀= 3,548.13 nM). (S)-Pramipexole is selective for dopamine D_2-4receptors (K_is = 954.99, 1,698.24, 12.59, 128.82 nM for D_2S, D_2L, D₃, and D₄receptors, respectively, in a radioligand binding assay) over D₁and D₅receptors (K_is = >10,000 nM for both).²It prevents MPTP-induced decreases in the number of dopaminergic neurons in the substantia nigra pars compacta in common marmosets when administered at a dose of 60 μg/kg per day before, during, and after administration of MPTP.³Formulations containing (S)-pramipexole have been used in the treatment of Parkinson's disease and restless legs syndrome.

1.Newman-Tancredi, A., Cussac, D., Audinot, V., et al.Differential actions of antiparkinson agents at multiple classes of monoaminergic receptor. II. Agonist and antagonist properties at subtypes of dopamine D2-like receptor and α1/α2-adrenoceptorJ. Pharmacol. Exp. Ther.303(2)805-814(2002) 2.Millan, M.J., Maiofiss, L., Cussac, D., et al.Differential actions of antiparkinson agents at multiple classes of monoaminergic receptor. I. A multivariate analysis of the binding profiles of 14 drugs at 21 native and cloned human receptor subtypesJ. Pharmacol. Exp. Ther.303(2)791-804(2002) 3.Iravani, M.M., Haddon, C.O., Cooper, J.M., et al.Pramipexole protects against MPTP toxicity in non-human primatesJ. Neurochem.96(5)1315-1321(2006)