Positron emission tomography evaluation of oxime countermeasures in live rats using the tracer O-(2-[¹⁸ F]fluoroethyl)-O-(p-nitrophenyl)methylphosphonate [¹⁸ F]-VXS.

ABSTRACT: Oxime antidotes regenerate organophosphate-inhibited acetylcholinesterase (AChE). Although they share a common mechanism of AChE reactivation, the rate and amount of oxime that enters the brain are critical to the efficacy, a process linked to the oxime structure and charge. Using a platform based on the organophosphate [¹⁸ F]-VXS as a positron emission tomography tracer for active AChE, the in vivo distribution of [¹⁸ F]-VXS was evaluated after an LD₅₀ dose (250 μg/kg) of the organophosphate paraoxon (POX) and following oximes as antidotes. Rats given [¹⁸ F]-VXS tracer alone had significantly higher radioactivity (two- to threefold) in the heart and lung than rats given LD₅₀ POX at 20 or 60 min prior to [¹⁸ F]-VXS. When rat

SUBMITTER: Hayes TR 

PROVIDER: S-EPMC7677195 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature