Primate Equilibrium Performance Following Soman Exposure: Effects of Repeated Acute Exposure with Atropine Therapy

摘要

Performance by well-trained rhesus monkeys of the Primate Equilibrium Platform (PEP) task was measured to determine the median effective dose (ED50) of the nerve agent soman for minimal but reliably detectable decrements in PEP performance. The method of simultaneous tolerance limits provided the criterion for a performance decrement. The up and down method provided ED50 estimates. Atropine therapy was given immediately after each soman dose. The same atropine dosage (97 ug/kg) was given during baseline testing sessions before and after each soman exposure. Three successive ED50 determinations were made. Each monkey received 3 soman dose (1.97-2.78 ug/kg) 6 to 8 weeks apart. Neither baseline PEP performance nor soman ED50 changed significantly as result of repeated soman exposure under these conditions. We concluded that: (1) the rhesus monkey - PEP performance model provides a sensitive and reliable indicator of the behavioral toxicity of soman; (2) soman dosages near the threshold for inducing performance decrements produce no carry over effects that are detectable either in baseline performance or in sensitivity to subsequent soman exposures, indicating that valuable primate resources can be reused in chemical defense experiments; and (3) therapeutic doses of atropine alone did not reduce the acute effects of soman on PEP performance.