L-3,4-Dihydroxyphenylalanine induces ptosis through a GPR143-independent mechanism in mice

Through its conversion to dopamine by aromatic l-amino acid decarboxylase (aadc),l-3,4-dihydroxyphenylalanine (l-dopa) replenishes depleted brain dopamine in parkinson's disease patients. we recently identified gpr143 as a candidate receptor for l-dopa. in this study,we investigated the behavioral actions of l-dopa in wild type (wt) and gpr143-deficient mice. l-dopa dose-dependently (10–100 mg/kg,i.p.) induced ptosis under treatment with 3-hydroxybenzylhydrazine,a centrally acting aadc inhibitor. this effect was not mimicked by 3-o-methyldopa. l-dopa-induced ptosis in gpr143-deficient mice to a similar extent as in wt mice. these results suggest that l-dopa induces ptosis in a gpr143-independent fashion in mice. © 2016 the authors