Figure 3

Prodynorphin deficiency enhances MPTP- or MA-induced decreases in TH expression and DA level. Dyn^+/+ and Dyn^−/− received MPTP (15 or 20 mg/kg, i.p.) or MA (5 or 7 mg/kg, i.p.) as described in Figure 1. TH expression and DA and its metabolites were examined 7 days after the last treatment with MPTP or MA. Quantification of TH expression was performed as shown in A and B. The levels of dopamine (DA; C, D) and its metabolites, 3,4-hydroxyphenylacetic acid (DOPAC; E, F) and homovanillic acid (HVA; G, H), were determined by HPLC. The turnover rate was evaluated using the ratio of (DOPAC + HVA)/DA (I, J). Each value is mean ± S.E.M of eight mice. *P <0.05, **P < 0.01, ***P < 0.001 vs. respective saline group, #P <0.05, ##P <0.01, ###P <0.001 vs. MPTP- or MA-treated Dyn^+/+ (two-way ANOVA followed by post-hoc Tukey HSD test or pairwise comparison with paired t-test).