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Non-cholinergic intervention of sarin nerve agent poisoning
Thomas W Sawyer1, John Mikler, Catherine Tenn
1Defence Research & Development Canada-Suffield, Box 4000, Medicine Hat, Alberta, Canada T1A 8K6. Thomas.Sawyer@drdc-rddc.gc.ca
Toxicology
|February 21, 2012
Summary
Anesthetics like propofol and high oxygen levels protect against sarin (GB) nerve agent poisoning in swine. These findings suggest new non-cholinergic treatments for organophosphorus nerve agent casualties.
Area of Science:
- Toxicology
- Pharmacology
- Veterinary Medicine
Background:
- Sarin (GB) is a highly toxic organophosphorus nerve agent.
- Understanding protective mechanisms against GB is crucial for developing medical countermeasures.
- Anesthetic agents and oxygen levels may influence GB toxicity.
Purpose of the Study:
- To investigate the protective effects of different anesthetic regimens and oxygen tensions against sarin (GB) toxicity in domestic swine.
- To evaluate the role of propofol and high oxygen concentrations in mitigating GB poisoning.
- To explore potential non-cholinergic protective mechanisms against organophosphorus nerve agents.
Main Methods:
- Domestic swine were anesthetized with isoflurane, ketamine, or propofol.
- Animals were exposed to varying concentrations of sarin (GB) under different oxygen tensions (30% and 100%).
- Lethal dose 50 (LD50) values were determined, and severity of poisoning, recovery time, and cognitive function were assessed.
Main Results:
- Propofol and ketamine anesthesia showed protective effects against GB toxicity compared to isoflurane at 30% oxygen.
- Using 100% oxygen significantly enhanced protection against GB poisoning across all anesthetic regimens, especially with propofol and isoflurane (>33x).
- Survivors of high GB doses under propofol anesthesia showed no cognitive impairment, and protective treatments did not prevent cholinesterase inhibition.
Conclusions:
- Propofol exhibits protective properties against GB nerve agent toxicity.
- Oxygen tension plays a significant role in the protective effects against GB poisoning.
- The study suggests the existence of non-cholinergic protective mechanisms against organophosphorus nerve agents, offering potential for novel therapeutic strategies.
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