BACKGROUND: The method of continual determination of the rat blood cholinesterase activity was developed to study the changes of the blood cholinesterases following different intervetions. AIMS: The aim of this study is registration of cholinesterase activity in the rat blood and its changes to demonstrate detoxification capacity of rats to inactivate sarin or VX in vivo. METHODS: The groups of female rats were premedicated (ketamine and xylazine) and cannulated to a. femoralis. Continual blood sampling (0.02 ml/min) and monitoring of the circulating blood cholinesterase activity were performed. Normal activity was monitored 1-2 min and then the nerve agent was administered i.m. (2×LD50). Using different time intervals of the leg compression and relaxation following the agent injection, cholinesterase activity was monitored and according to the inhibition obtained, detoxification capacity was assessed. RESULTS: Administration of sarin to the leg, then 1 and 5 min compression and 20 min later relaxation showed that further inhibition in the blood was not observed. On the other hand, VX was able to inhibit blood cholinesterases after this intervention. CONCLUSIONS: The results demonstrated that sarin can be naturally detoxified on the contrary to VX. Described method can be used as model for other studies dealing with changes of cholinesterases in the blood following different factors. and J. Bajgar, J. Cabal, J. Kassa, M. Pavlík
The reactivating and therapeutic efficacy of two combinations of oximes (HI‑6 + trimedoxime and HI‑6 + K203) was compared with the effectiveness of antidotal treatment involving single oxime (HI‑6, trimedoxime, K203) using in vivo methods. In vivo determined percentage of reactivation of cyclosarin‑inhibited blood and tissue acetylcholinesterase in poisoned rats showed that the reactivating efficacy of both combinations of oximes is slightly higher than the reactivating efficacy of the most effective individual oxime in blood, diaphragm as well as in brain. Moreover, both combinations of oximes were found to be slightly more efficacious in the reduction of acute lethal toxic effects in cyclosarin‑poisoned mice than the antidotal treatment involving single oxime. Based on the obtained data, we can conclude that the antidotal treatment involving chosen combinations of oximes brings a beneficial effect for its ability to counteract the acute poisoning with cyclosarin., Jiří Kassa, Jana Zdarová Karasová, Růžena Pavlíková, Filip Caisberger, Jiří Bajgar, and Literatura 36