Low-Level Sarin Vapor Exposure in Rats: Effect of Exposure Concentration and Duration on Pupil Size
Abstract
The probability of sarin (GB) vapor-induced miosis was estimated in rats exposed to various combinations of exposure concentration and duration. Groups of male and female rats (Sprague-Dawley) were exposed to one of a series of GB vapor concentrations for a single duration (10-240 minutes), in a whole-body dynamic chamber. Separate effective concentrations for miosis (defined as a post-exposure pupil diameter 50% or less of the pre-exposure pupil diameter) in 50% of the exposed population (EC50) and corresponding dose-response slopes were determined, for each exposure time, by the Bliss probit method. Contrary to that predicted by Haber's rule, ECT50 values increased with exposure duration (i.e., the CT for 50% of the exposed population to show miosis was not constant over time). Linear regression analysis was used to derive a model of low-level GB vapor-induced pupil diameter changes in the rat as a function of exposure concentration and time. Female rats were more sensitive to GB vapor toxicity than male rats. Miosis was the only clinical sign noted following GB vapor exposure. Blood esterase (acetylcholinesterase, butyrylcholinesterase, and carboxylesterase) activities were not inhibited by exposure to the low-level range of GB vapor.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2002
- Accession Number
- ADA402869
Entities
People
- Bernardita P. Gaviola
- David C. Burnett
- James H. Manthei
- Robert J. Mioduszewski
- Ruth A. Way
Organizations
- Edgewood Chemical Biological Center