Low-Level Cyclosarin (GF) Vapor Exposure in Rats: Effect of Exposure Concentration and Duration on Pupil Size
Final rept. Feb-Oct 2002
EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
Pagination or Media Count:
Probability of cyclosarin GF miosis defined as post-exposure pupil diameter 50 or less of pre-exposure pupil diameter was estimated in rats exposed to combinations of exposure concentration and duration. Groups of male and female rats were exposed to OF vapor for a single duration 10, 60, or 240 min in a whole-body dynamic chamber. Pupil diameter was measured by infrared camera technique. For six combinations of gender and exposure duration, effective concentration for miosis in 50 of exposed population and common probit slope were determined. Contrary to Habers rule, ECt50 values increased with exposure duration. Female rats were more sensitive to GF vapor toxicity than male rats. Miosis was the only clinical sign noted following GF vapor exposure. Mydriasis was not observed in the present study. Depression of blood esterase acetylcholinesterase, butyrylcholinesterase, and carboxylesterase activities due to low level range of GF vapor concentrations was also investigated. Cyclosarin was regenerated from blood samples of vapor-exposed rats by addition of fluoride ion at pH 4, and the samples were analyzed by GC-FPD and GC-MS. Levels of regenerated GF in red blood cell fraction of samples were 5 to 40 times lower than in plasma. All controls were negative for regenerated GF.
- Inorganic Chemistry