Journal of analytical toxicology

Assay of chicken brain neurotoxic esterase activity using leptophosoxon as the selective neurotoxic inhibitor.

PMID 7278155


Hen brain microsomal preparation has phenyl valerate-hydrolyzing activity associated with neurotoxic esterase activity. Part of that activity is due to paraoxon-insensitive esterases and a sub-part of this is sensitive to neurotoxic organophosphates, i.e., mipafox and leptophosoxon. This neurotoxic agent sensitive esterase activity is referred to as neurotoxic esterase (NTE). Because of the commercial unavailability and high toxicity of mipafox, which is usually used as the selective inhibitor for assaying NTE, leptophosoxon was used as an alternative to mipafox. Results indicated that the NTE fraction of hen brain microsomal PV-hydrolyzing activity is the same target for either mipafox or leptophosoxon. The inhibitory effect of leptophosoxon against that fraction was much higher than that of mipafox. The availability of leptophos/leptophosoxon makes this assay very useful for screening organophosphorus esters for neurotoxic effects.