Importance of the Reactivation of Fosdrin-inhibited Acetylcholinesterase in Brain and Diaphragm invivo for the Therapeutic Efficacy of Oximes Against Fosdrin-induced Intoxication of Rats

Summary

Background.
The composition of the causal antidotal therapy of subjects, poisoned with organophosphorusinsecticides, has not been satisfactorily solved till now in spite of the knowledge of the basic mechanism of actionof these toxic substances. The purpose of this study is to evaluate which of currently used or perspectiveacetylcholinesterase reactivators seems to be the most efficacious to protect poisoned subjects.Methods and Results. In experiments on white laboratory rats, the reactivating efficacy of selected acetylcholin-esterase reactivators (oximes), administered at equimolar doses, was evaluated in target tissue of toxic effects oforganophosphorus insecticides (diaphragm, brain) and compared with their therapeutic efficacy in the case ofprophylactic administration with the help of the evaluation of mean efficacy dose of oximes, possible to protect ratsexposed to supralethal dose of organophosphorus insecticide fosdrin for 24 hours. Our findings confirm that thereare not statistically significant differences in reactivating and therapeutic efficacy of oximes tested against fosdrinin rats.Conclusions. The perspective acetylcholinesterase reactivators (H oximes) seem to be as suitable as currentlyused oximes for the therapy of acute poisonings with organophosphorus insecticides although they are notsignificantly more efficacious than currently used oximes as in the case of the treatment of poisoning with highlytoxic organophosphorus compounds.

Key words:
fosdrin, rat, HI-6, BI-6, obidoxime, methoxime, pralidoxime, atropine.