This study aimed at investigating the gene expression profile in basal ganglia of hexa-valence chromium exposed rat based on cDNA array analysis. For cDNA array, Sprague-Dawley male rats (300 ± 25 g) were administrated with 15 mg/kg B.W/day of potassium dichromate by gavage (0.3 ml) dissolved in saline for 10 days (n=5). For dose-related gene expression analysis, rats were administrated with 0, 1, 5 mg/kg B.W/day of potassium dichromate for 10 days. Control rats were administrated with equal volume of saline (n=5). For cDNA array analysis, RNA samples were extracted from brain tissue and reverse-transcribed in the presence of [α³²P]-dATP. Membrane sets of the Atlas array II and Toxicology array kits were hybridized with cDNA probe sets. RT-PCR and Northern blot hybridization methods were employed for validation and assessment of the dose-related gene expression profile, respectively. Among the 2352 cDNAs, 43 genes showed significant (>two-fold) changes in expression. 22 genes were up-regulated and 21 genes were down-regulated in the 15 mg/kg B.W/day hexa-valence chromium treated group than control. According to the Northern blot hybridization analysis, heat shock protein 47, neurodegeneration associated protein 1 and pituitary specific growth factor 1a genes were up-regulated, but Gamma-aminobutyl-acid a1 subunit, neuroligin2, brain calcium-transporting plasma membrane type ATPase genes were down-regulated even in the low-dose of hexa-valence chromium exposed group (1 mg/kg B.W/day) than control. Genes that detected in this study may be closely related to the hexa-valence chromium-induced neurotoxicity in the rat basal ganglia and addition study of these genes can give some more useful information about the neuro-toxic mechanism by hexa-valence chromium.

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