Decreased tyrosine hydroxylase protein and dopamine transporter levels in the mouse striatum following MPTP treatment. 125I-RTI-121 specific binding to dopamine transporter (DAT) was measured with receptor binding autoradiography and showed a remarkable decrease following MPTP treatment without any effect of intravenous immunoglobulin (IVIg). (A) Representative autoradiograms and (B) quantification. Statistical analysis: mean ± standard error of the mean (SEM; n = 11 to 15/group). One-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison test, ***P <0.001 control-MPTP versus control-vehicle, ###
P <0.001 IVIg-MPTP versus IVIg-vehicle. Striatal tyrosine hydroxylase (TH) protein level was also decreased following MPTP intoxication. (C) Representative Western blot of TH in MPTP-mice treated with IVIg or vehicle. (D) Densitometric quantification of the Western blots. Data presented as mean ± SEM (n = 11 to 15/group). Statistical analysis: one-way ANOVA followed by Dunnett’s multiple comparison test. ***P <0.001, *P <0.05 versus control-vehicle. Besides the downregulating effect of MPTP, a significant IVIg-induced decrease of TH in the striatum of mice was observed in vehicle-treated mice (*P <0.05 vs. control-vehicle) and was further evidenced using two-way ANOVA analyses in both vehicle and MPTP groups (∞
P <0.05 IVIg vs. control). Percentage of control values is indicated for significant variation (vehicle-control vs. MPTP-control or vehicle-IVIg vs. MPTP-IVIg, respectively).