A COMPARISON OF THE SENSITIVITYOF DIFFERENT STRAINS OF MICE TO SARIN

Summary Poisoning from chemical warfare agents (CWAs) such as sarin is associated with neuronal degeneration. This damage is thought to result from glutamatergic excitotoxicity such as seen following kainic acid induced seizures. In order to search for novel neuroprotectants it is necessary to select good mouse models for susceptibility to nerve agent-induced seizures and the resulting neurodegeneration. The mouse strains tested (C57BL/6, ICR, DBA/2, SW, and FVB/N, Harlan Laboratory) had widely different sensitivity to sarin as shown by differences in the dose required resulting in 50% mortality, LD 50 . Differences also were observed among the strains in Fluoro-Jade C staining with the C57BL/6 and DBA having little to no staining when euthanized at 7 days whereas the other strains did. Differences in acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity were found among the strains as well. The ICR strain was excluded from the FOB and weight data due to difficulty getting a consistent LD 50 . Weight loss and FOB scores were similar for all strains. All strains had inhibited AChE activity after sarin exposure and exhibited inhibition of CNS BuChE after sarin exposure but only ICR and SW reached significance.