Expression and distribution of redox regulatory protein, thioredoxin after metabolic impairment by 3-nitropropionic acid in rat brain.

Thioredoxin (TRX) is a small, multifunctional protein with a redox-active site and multiple biological functions that include reducing activity for reactive oxygen intermediates. We assayed TRX by immunohistochemical methods in the rat brain after intraperitoneal injection of 3-nitropropionic acid (3-NP), an irreversible inhibitor of succinate dehydrogenase. Systemic administration of 3-NP produced lateral striatal, hippocampal CA1 and CA3 lesions in the present study. The immunoreactivity for TRX was enhanced in hippocampal CA3, dentate gyrus and lateral striatum, but not detected in hippocampal CA1 subfield after 3-NP intoxication. The data suggest that TRX may play an important role in the pathogenesis of 3-NP neurotoxicity.