title: A comparison of the therapeutic and reactivating efficacy of newly developed oximes (K117, K127) and currently available oximes (obidoxime, trimedoxime, HI-6) in tabun-poisoned rats and mice.
abstract: The potency of newly developed bispyridinium compounds (K117, K127) to reactivate tabun-inhibited acetylcholinesterase and reduce tabun-induced lethal toxic effects was compared with currently available oximes (obidoxime, trimedoxime, oxime HI-6) by using in vivo methods. A study that determined the percentage of reactivation of tabun-inhibited blood and tissue acetylcholinesterase in poisoned rats showed that the reactivating efficacy of newly developed oxime K127 is comparable with obidoxime and trimedoxime in blood but lower than the reactivating potency of trimedoxime and obidoxime in the diaphragm and brain. The potency of another newly developed K117 to reactivate tabun-inhibited acetylcholinesterase is comparable with obidoxime or trimedoxime in the diaphragm, but it is significantly lower than the reactivating potency of trimedoxime and obidoxime in the blood and brain. The oxime, K127, was also found to be relatively effective in reducing lethal toxic effects in tabun-poisoned mice. Its therapeutic efficacy is consistent with the therapeutic potency of obidoxime. On the other hand, the potency of the oxime, K117, to reduce acute toxicity of tabun is significantly lower compared to trimedoxime and obidoxime. The therapeutic efficacy of K117 and K127 corresponds to their potency to reactivate tabun-inhibited acetylcholinesterase, especially in the diaphragm and brain. Contrary to obidoxime and trimedoxime, the oxime, HI-6, is not an effective oxime in the reactivation of tabun-inhibited acetycholinesterase and in reducing the lethal effects of tabun. The reactivating and therapeutic potency of both newly developed oximes does not prevail over the effectiveness of currently available obidoxime and trimedoxime and, therefore, they are not suitable for their replacement of commonly used oximes for the treatment of acute tabun poisoning.
authors.affiliation: Department of Toxicology, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic. kassa@pmfhk.cz
authors.forename: Jiri
authors.initials: J
authors.lastname: Kassa
authors.forename: Jana
authors.initials: J
authors.lastname: Karasova
authors.forename: Kamil
authors.initials: K
authors.lastname: Musilek
authors.forename: Kamil
authors.initials: K
authors.lastname: Kuca
authors.forename: Young-Sik
authors.initials: YS
authors.lastname: Jung
mesh_terms: D000110:Acetylcholinesterase / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000931:Antidotes / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000506:poisoning*; D003964:Diaphragm / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D009768:Obidoxime Chloride / Q000494:pharmacology; D062025:Organophosphate Poisoning; D010755:Organophosphates; D010091:Oximes / Q000494:pharmacology*; D011726:Pyridinium Compounds / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014289:Trimedoxime / Q000494:pharmacology
chemical_list: D000931:Antidotes; D002800:Cholinesterase Inhibitors; C530923:K117 compound; C530922:K127 compound; D010755:Organophosphates; D010091:Oximes; D011726:Pyridinium Compounds; D009768:Obidoxime Chloride; D014289:Trimedoxime; D000110:Acetylcholinesterase; C022870:asoxime chloride; C009374:tabun