| 18788997 |
Taylor JT, Davis E, Dabisch P, Horsmon M, Li M, Mioduszewski R: Alterations in autonomic function in the guinea pig eye following exposure to dichlorvos vapor. J Ocul Pharmacol Ther. 2008 Oct;24(5):473-9.
The present study investigated the effect of the organophosphate, dichlorvos (DDVP), on ocular function and cholinesterase activity in guinea pigs, using a single-animal-head-only vapor exposure system. All animals exhibited signs of mild organophosphate poisoning (e.g., salivation, chewing, lacrimation, urination, defecation, and rhinorrhea) after the 20-min exposure, regardless of the DDVP exposure concentration (e.g., 35 mg/m (3), 55 mg/m (3), and 75 mg/m (3)). Pupil constriction or miosis was the most pronounced effect seen after vapor exposure. The postexposure pupil size for the 35 mg/m (3) group was 45.8 +/- 3.68% of the preexposure baseline measurement. Postexposure pupil size in the 55- (38 +/- 1.36%) and 75 mg/m (3) (38.1 +/- 1.72%) groups was significantly less than both the preexposure baseline level and the 35 mg/m (3) group. All groups exhibited enhanced an pupillary response to light after DDVP exposure. The enhanced light response remained even after recovery from miosis (approximately 1 h after exposure). Measurement of cholinesterase activity revealed that even though pupil size had recovered, acetyl- and butyrylcholinesterase remained significantly inhibited in the blood. |
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