2-Octyl-4H-1,3,2-benzodioxaphosphorin 2-oxide labelled with tritium in the octyl and aryl moieties

Localization of [3H]octylphosphonyl-labeled neuropathy target esterase by chicken nervous tissue autoradiography

Neuropathy target esterase (NTE) undergoes phosphorylation and aging as the initial steps in organophosphorus (OP)-induced delayed neuropathy (OPIDN). Localization of NTE is an important step in characterizing the mechanism of OPIDN. Earlier histochemical immunoreactivity or esterase assays localized NTE in areas of the brain and spinal cord rich in neuronal cell bodies and in the dorsal root ganglion. We use a more direct and quantitative autoradiographic approach of forming phosphorylated and aged [3H]octylphosphonyl-NTE on treatment with the highly potent [octyl-3H]octyl-4H-1,3,2-benzodioxaphosphorin 2-oxide to determine NTE as the labeling site resistant to the non-neuropathic paraoxon and sensitive to the neuropathic mipafox. NTE is observed in the cerebral cortical layer, some layers of the optic tectum, the gray matter of the spinal cord and the sensory neurons of the dorsal root ganglion to a higher extent than in adjacent areas.