TH and Huntington disease: On the contrary, in a pharmacological model of HD induced by malonate, Alfinito et al. (2003) observed that intraperitoneal and intrastriatal A1R blockade with the A1R antagonist CPX potentiated the effect of malonate, reducing striatal dopamine levels, tyrosine hydroxylase (TH) content, and GABA levels as well as GABAergic and dopaminergic neuronal loss (Alfinito et al., 2003).