Effect of genetic deletion and pharmacological antagonists of P2X
receptors on the level of DA and its metabolites in the striatum and animal survival after in vivo MPTP treatment. Wild-type (WT) and P2X7 -/- (KO) mice were treated with saline or with MPTP in doses indicated in the legend (4 × 10-20 mg/kg i. p.) and sacrificed 72 h later. A, B, C and E. Striatal samples were analyzed using HPLC and the amount of (A, E) dopamine (DA) 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), (B) norepinephrine (NE), 3-methoxityramine (3-MT) and (C) 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) is expressed in nmol/mg protein (n = 5-8). D. Survival curves of WT and P2X7 -/- (KO) mice subjected to in vivo MPTP (4 × 20 mg/kg i.p.) treatment (n = 16/group). E. Effect of Brilliant blue G (BBG, 50 mg/kg i.p.) pretreatment on the level of DA and its metabolites in the striatum of WT mice after in vivo MPTP (4 × 20 mg/kg) treatment. BBG was injected 18 h before the first MPTP injection. Asterisks indicate significant differences from the corresponding saline-injected mice or between WT and KO mice as indicated (*P < 0.05, ** P < 0.01, *** P < 0.01).