Novel neuroprotective effects with O-benzyl derivative of pralidoxime in soman-intoxicated rodents

Eur J Pharmacol. 2005 Oct 3;521(1-3):59-69. doi: 10.1016/j.ejphar.2005.07.033. Epub 2005 Sep 19.

Abstract

Pharmacological properties of oxime reactivators, not related to its ability to regenerate or reactivate nerve agent-inhibited acetylcholinesterase located at nerve synapses, have been reported to be important in protecting against poisoning by the nerve agent soman. Such non-reactivation effects have thus far been associated only with bispyridinium oximes. This study investigated the possibility of creating similar non-reactivation therapeutic effects in the mono-pyridinium ring oxime, pralidoxime (2-PAM) through attachment of alkyl groups of increasing chain length to the oxime functional group. Of the 4 derivatives investigated, only the O-benzyl derivative displayed strong sedative effects in mice and mitigated the development of motor convulsions following soman challenge (1.8 x LD50, subcutaneous). Anticonvulsant effects of this compound were enhanced by co-administration of a non-anticonvulsant dose of atropine sulfate. Administration of equivalent amount of other O-derivatives of pralidoxime failed to elicit similar anticonvulsant actions. Electroencephalographic (EEG) and histopathological studies using the rat model, intoxicated with a lethal dose (1.6 x LD50, s.c.) of soman, confirmed O-benzyl derivative neuroprotective capabilities when used as a pretreatment drug. Microdialysis studies revealed that its neuroprotective effect is related to its ability to attenuate soman-induced increase in acetylcholine.

Publication types

  • Comparative Study

MeSH terms

  • 3,4-Dihydroxyphenylacetic Acid / metabolism
  • Acetylcholine / metabolism
  • Analysis of Variance
  • Animals
  • Anticonvulsants / pharmacology
  • Atropine / pharmacology
  • Benzene Derivatives / chemistry
  • Benzene Derivatives / pharmacology*
  • Cholinesterase Inhibitors / toxicity
  • Cholinesterase Reactivators / pharmacology
  • Corpus Striatum / drug effects
  • Corpus Striatum / metabolism
  • Dopamine / metabolism
  • Drug Synergism
  • Electroencephalography / drug effects
  • Female
  • Homovanillic Acid / metabolism
  • Hydroxyindoleacetic Acid / metabolism
  • Mice
  • Microdialysis
  • Neuroprotective Agents / pharmacology*
  • Oximes
  • Pralidoxime Compounds / chemistry
  • Pralidoxime Compounds / pharmacology*
  • Pyridinium Compounds / chemistry
  • Pyridinium Compounds / pharmacology
  • Rats
  • Rats, Wistar
  • Seizures / mortality
  • Seizures / physiopathology
  • Seizures / prevention & control
  • Serotonin / metabolism
  • Soman / toxicity*
  • Survival Rate
  • Time Factors

Substances

  • Anticonvulsants
  • Benzene Derivatives
  • Cholinesterase Inhibitors
  • Cholinesterase Reactivators
  • Neuroprotective Agents
  • Oximes
  • Pralidoxime Compounds
  • Pyridinium Compounds
  • 3,4-Dihydroxyphenylacetic Acid
  • Serotonin
  • Hydroxyindoleacetic Acid
  • Atropine
  • Soman
  • asoxime chloride
  • Acetylcholine
  • pralidoxime
  • Dopamine
  • Homovanillic Acid