An easy method for the determination of active concentrations of cholinesterase reactivators in blood samples: Application to the efficacy assessment of non quaternary reactivators compared to HI-6 and pralidoxime in VX-poisoned mice

Chem Biol Interact. 2017 Apr 1:267:11-16. doi: 10.1016/j.cbi.2016.03.009. Epub 2016 Mar 10.

Abstract

Organophosphorus nerve agents, like VX, are highly toxic due to their strong inhibition potency against acetylcholinesterase (AChE). AChE inhibited by VX can be reactivated using powerful nucleophilic molecules, most commonly oximes, which are one major component of the emergency treatment in case of nerve agent intoxication. We present here a comparative in vivo study on Swiss mice of four reactivators: HI-6, pralidoxime and two uncharged derivatives of 3-hydroxy-2-pyridinaldoxime that should more easily cross the blood-brain barrier and display a significant central nervous system activity. The reactivability kinetic profile of the oximes is established following intraperitoneal injection in healthy mice, using an original and fast enzymatic method based on the reactivation potential of oxime-containing plasma samples. HI-6 displays the highest reactivation potential whatever the conditions, followed by pralidoxime and the two non quaternary reactivators at the dose of 50 mg/kg bw. But these three last reactivators display equivalent reactivation potential at the same dose of 100 μmol/kg bw. Maximal reactivation potential closely correlates to surviving test results of VX intoxicated mice.

Keywords: Blood clearance; Cholinesterase; Organophosphorus-nerve agents; Oxime; Reactivation.

MeSH terms

  • Acetylcholinesterase / chemistry
  • Acetylcholinesterase / metabolism
  • Animals
  • Blood Chemical Analysis / methods*
  • Blood-Brain Barrier / drug effects*
  • Blood-Brain Barrier / metabolism
  • Chemical Warfare Agents / toxicity*
  • Cholinesterase Reactivators / blood*
  • Erythrocytes / cytology
  • Erythrocytes / enzymology
  • Half-Life
  • Humans
  • Injections, Intraperitoneal
  • Male
  • Mice
  • Organothiophosphorus Compounds / toxicity*
  • Oximes / metabolism
  • Oximes / pharmacology*
  • Pralidoxime Compounds / metabolism
  • Pralidoxime Compounds / pharmacology*
  • Protective Agents / metabolism
  • Protective Agents / pharmacology
  • Pyridinium Compounds / metabolism
  • Pyridinium Compounds / pharmacology*

Substances

  • Chemical Warfare Agents
  • Cholinesterase Reactivators
  • Organothiophosphorus Compounds
  • Oximes
  • Pralidoxime Compounds
  • Protective Agents
  • Pyridinium Compounds
  • VX
  • Acetylcholinesterase
  • asoxime chloride
  • pralidoxime