Toxicant Effects on the Nervous System

MPTP is one example of a toxicant that causes direct structural damage to neurons, resulting in loss of function. In the following sections, other types of structural and functional effects of neurotoxicants are described. Structural effects are divided into three primary types effects on myelin formation, primary damage to axons, and direct promotion of cell death. Neurons may also be secondarily affected by neurotoxicants 

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C. Neurotoxiiis Chemicals which produce their primary toxic effects on the nervous system ... 

No information is available on the adverse health effects of hexachloroethane in humans. Animal studies revealed that hexachloroethane primarily causes liver and kidney toxicity. Effects on the nervous system and lungs have also been reported. The mechanism by which these effects are mediated is not well characterized. Reductive metabolism by cytochrome P-450 and production of a free radical intermediate have been suggested as factors in hexachloroethane-induced hepatotoxicity (Nastainczyk et al. 1982a Thompson et al. 1984 Town and Leibman 1984). Accordingly, one possible approach may be to reduce free radical injury. To that end, oral administration of N-acetylcysteine can be used as a means of reducing free radical injury. Also, oral administration of vitamin E and vitamin C may be of value since they are free radical scavengers. 

Although there is the potential for nerve agents to have direct toxic effects on the nervous system, there is no evidence that such effects occur in humans at doses lower than those causing cholinesterase inhibition. For the purpose of evaluating potential health effects, inhibition of blood cholinesterase is generally considered the most useful biological endpoint. 

Neurotoxins are agents that can cause toxic effects on the nervous system that may produce emotional or behavior abnormalities. 

Target organ effect Damage caused in a specific organ following exposure to certain chemicals. For example, a "neurotoxin" is a chemical, such as mercury, that produces its primary toxic effect on the nervous system. 

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