Effects of Repeated Low-Dose Sarin Exposure

摘要

Chemical warfare nerve agents (CWNAs), such as sarin, soman, and VX, are organophosphorus compounds (OPs). They disrupt normal nervous system transmissions through the irreversible inhibition of acetylcholinesterase (AChE), the enzyme that breaks down the cholinergic neurotransmitter (NT) acetylcholine (ACh). The buildup of ACh in response to a large exposure to nerve agents can lead, unless promptly treated, to muscle weakness, increased secretions (i.e., lacrimation, rhinorrhea, salivation), convulsions and seizures, respiratory depression, coma, and death (Taylor, 2001). The progression of signs, their neuropharmacological basis, and toxic consequence elicited from acute high-dose exposures have been well characterized (McDonough and Shih, 1993, 1997; Shih et al., 2003). However, much less is known about the long-term effects of repeated low-dose CWNA exposure. Comprehensive reviews of the available literature on the long- term health effects of exposure to low level CWNAs have been published (Panel on Anticholinesterase Chemicals, 1982; Coordinating Subcommittee, 1985; Moore, 1998; Romano et al., 2001). In general, exposure to low-level CWNAs is a potential emerging health hazard that requires further investigation (Romano et al., 2001).