Transcriptional regulation of cytochrome c oxidase subunits in rat brain following sodium arsenite exposure

Oxidative stress-mediated mitochondrial dysfunction is considered the major mechanism of arsenic-induced neurotoxicity. With the present study, the regulation of the 13 subunits of cytochrome c oxidase in rat brain following arsenic exposure was evaluated. Rats were exposed to sodium arsenite (2.5 mg/kg b.wt., by gavage) for 12 weeks. The mRNA expression of the subunits was analysed using reverse transcription polymerase chain reaction. The mRNA expression of all the mitochondria-encoded subunits and selective nuclear-encoded subunits was downregulated. Analysis of mRNA expression of nuclear respiratory factor-1 and nuclear respiratory factor-2 also showed downregulation.