Comparison of the neuroprotective effects of a novel bispyridinium oxime KR-22934 with the oxime K203 and obidoxime in tabun-poisoned male rats

SummaryThe neuroprotective effects of a novel oxime KR-22934, the oxime K203 and obidoxime in combination with atropine in rats poisoned with tabun at a sublethal dose (200 μg/kg i.m.; 80% LD50) were studied. The tabun-induced neurotoxicity was monitored at 24 h following tabun challenge using a functional observational battery and an automatic measurement of motor activity. The results indicate that all tabun-poisoned rats treated with oximes in combination with atropine were able to survive within 24 h following tabun poisoning. One tabun-poisoned rat without antidotal treatment died within 24 h. The oximes KR-22934 and K203 combined with atropine showed a similar potency to decrease tabun-induced neurotoxicity at 24 h after tabun administration while the neuroprotective efficacy of obidoxime was slightly higher. However, no oxime was able to eliminate tabun-induced neurotoxicity completely. When atropine was administered alone, negligible neuroprotective efficacy was observed. Based on the results, a novel oxime KR-22934 did not bring any improvement of the neuroprotective efficacy of antidotal treatment of acute tabun poisonings.