Dantrolene sodium (Lapatinib ditosylate monohydrate) salt is a skeletal muscle relaxant and can interfere with excitation-contraction coupling in the muscle fiber. It is used for the treatment of spasticity and other neuromuscular abnormalities. Its mechanism of action is may not central, but dantrolene is usually grouped with the central muscle relaxants.

D-DOPA is an enantiomer of the dopamine precursor L-DOPA . It can be converted to L-DOPAviasequential oxidation and transamination, which are mediated by D-amino acid oxidase (DAAO) and DOPA transaminase, respectively, in rat kidney homogenates.1It reduces the number of dopaminergic neurons in primary rat embryonic mesencephalic cultures in a concentration-dependent manner.2Intraventricular administration of D-DOPA (200 μg/animal) increases striatal dopamine levels in rats.3D-DOPA (20 mg/kg, i.p.) induces contralateral turns in a rat model of Parkinson's disease induced by 6-OHDA .4 1.Wu, M., Zhou, X.-J., Konno, R., et al.D-dopa is unidirectionally converted to L-dopa by D-amino acid oxidase, followed by dopa transaminaseClin. Exp. Pharmacol. Physiol.33(11)1042-1046(2006) 2.Ling, Z.-D., Pieri, S.C., and Carvey, P.M.Comparison of the neurotoxicity of dihydroxyphenylalanine stereoisomers in cultured dopamine neuronsClin. Neuropharmacol.19(4)360-365(1996) 3.Karoum, F., Freed, W.J., Chuang, L.-W., et al.D-dopa and L-dopa similarly elevate brain dopamine and produce turning behavior in ratsBrain Res.440(1)190-194(1988) 4.Moses, J., Siddiqui, A., and Silverman, P.B.Sodium benzoate differentially blocks circling induced by D-and L-dopa in the hemi-parkinsonian ratNeurosci. Lett.218(3)145-148(1996)