Seven new oxime-based acetylcholinesterase reactivators were compared with three currently available ones (obidoxime, trimedoxime, HI-6) for their ability to lessen cholinesterase inhibition in blood and brain of cyclosarin-treated rats. Oximes were given at doses of 5% their LD(50) along with 21 mg/kg atropine five min before the LD(50) of cyclosarin (120 ug/kg) was administered. Blood and brain samples were collected 30 minutes later. The greatest difference between acetylcholinesterase inhibition in blood of cyclosarin-treated rats was found after administration of HI-6 (40%), compared to 22% for trimedoxime and 6% for obidoxime. Only two of the seven newly synthesized oximes had any effect (K203 at 7%, K156 at 5%). Effective oximes against cyclosarin-inhibited plasma butyrylcholinesterase were HI-6 (42%), trimedoxime (11%), and K156 (4%). The oximes were less effective in brain than in blood, with reactivation values for HI-6 30% against acetylcholinesterase and 10% against butyrylcholinesterase. Values for newly synthesized oximes were less than 10% for K206, K269 and K203.

• Keywords
• acetylcholinesterase, butyrylcholinesterase, cyclosarin, oximes, reactivators,
• MeSH
• Acetylcholinesterase blood   metabolism   MeSH
• Atropine pharmacology   MeSH
• Rats MeSH
• Brain drug effects   enzymology   MeSH
• Organophosphorus Compounds toxicity   MeSH
• Oximes chemistry   pharmacology   MeSH
• Rats, Wistar MeSH
• Cholinesterase Reactivators chemistry   pharmacology   MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Acetylcholinesterase MeSH
• Atropine MeSH
• cyclohexyl methylphosphonofluoridate MeSH Browser
• Organophosphorus Compounds MeSH
• Oximes MeSH
• Cholinesterase Reactivators MeSH