[Changes of thioredoxin mRNA level in neurons insulted by sodium azide]

Oxidative stress has been considered to be associated with many neurodegenerative diseases, while mitochondrial damage is one of the important reasons that aggravate oxidative stress. Sodium azide (NaN3) is a specific inhibitor of mitochondrial cytochrome c oxidase (COX), which can be used to mimic neuronal damage induced by mitochondrial deficiency. In this experiment, the neurotoxic effects of NaN3 on cultured primary neurons were detected by means of cell viability measurement (MTT assay) and morphological observation, and an in vitro model of neuronal injury induced by NaN3 were established. Further the changes of thioredoxin mRNA level in cultured neurons insulted by NaN3 were analyzed by semiquantitative RT-PCR in order to explore the role of Trx, an important redox regulatory protein, in the process of neuronal injury. It was found that cultured neurons could be damaged by NaN3 in a dose- and time-dependent manner and the expression of Trx decreased during certain dose (0-32mmol/L) and time (0-4hr) of NaN3 treatment. The above data suggest that decreased the expression of Trx may be associated with oxidative stress induced by neuronal respiratory chain injury, which could impair neuronal protective mechanism.