Evaluation of miosis, behavior and cholinesterase inhibition from low-level, whole-body vapor exposure to soman in African green monkeys (Chlorocebus sabeus).
BACKGROUND
Relatively little is known about the effects of very low-level exposures to nerve agents where few signs or symptoms are present.


METHODS
African green monkeys (Chlorocebus sabeus) (n = 8) were exposed for 10 min, whole-body, to a single concentration of soman (0.028-0.891 mg/m³).


RESULTS
EC₅₀ values for miosis were determined to be 0.055 mg/m³ and 0.132 mg/m³ when defined as a 50 percent reduction in pupil area and diameter, respectively. In general, performance on a serial probe recognition task remained unchanged at lower concentrations, but responding was suppressed at the largest concentration tested. Soman produced concentration-dependent inhibition of acetylcholinesterase activity and, to a lesser extent, butyrylcholinesterase activity.


CONCLUSIONS
These results characterize threshold soman exposure concentrations that produce miosis in the absence of other overt signs of toxicity and extend previous studies indicating that miosis is a valuable early indicator for the detection of soman vapor exposure.
Genovese
Raymond F
RF
Division of Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910-7500, USA. Raymond.Genovese@US.ARMY.MIL
Benton
Bernard J
BJ
Oubre
John L
JL
Fleming
Patrick J
PJ
Jakubowski
E Michael
EM
Mioduszewski
Robert J
RJ
D000818:Animals; D002619:Chemical Warfare Agents / Q000633:toxicity*; D002522:Chlorocebus aethiops; D002802:Cholinesterases / Q000097:blood*; D005260:Female; D019570:Inhalation Exposure; D008570:Memory, Short-Term / Q000187:drug effects*; D015877:Miosis / Q000097:blood / Q000139:chemically induced*; D012999:Soman / Q000633:toxicity*
D002619:Chemical Warfare Agents; D012999:Soman; D002802:Cholinesterases