Lack of beneficial effects of intravenous immunoglobulin on depleted levels of dopamine and its metabolites. Catecholamines and indolamine were quantified using HPLC in the striatum of mice. Concentrations of (A) dopamine (DA), (B) homovanillic acid (HVA), and (C) 3,4-dihydroxyphenylacetic acid (DOPAC) remained decreased following MPTP injections and subsequent intravenous immunoglobulin (IVIg) treatment. (D) Concentration of serotonin. (A) to (D) Percentage of control values is indicated for significant variation (vehicle-control or vehicle-IVIg, respectively). Two-way analysis of variance (ANOVA) also revealed lower (B) HVA and (D) serotonin levels in IVIg groups. Values represent mean ± standard error of the mean of 11 to 15 animals per group. Statistical analysis: one-way ANOVA followed by Tukey’s multiple comparison test, ***P <0.001 control-MPTP versus control-vehicle, ###
P <0.001 IVIg-MPTP versus IVIg-vehicle; two-way ANOVA analyses, ∞
P <0.05 IVIg-treated versus control-treated animals.