Central nervous system organophosphate toxicity

All the organophosphates except echothiophate are distributed to all parts of the body, including the central nervous system. Therefore, central nervous system toxicity is an important component of poisoning with these agents. 

Carbamates also include pesticides such as Sevin, aldicarb, and carbaryl. They are more degradable than organophosphates and have lower dermal toxicides. Their toxicity is also due to inhibition of acetylcholinesterase but they do not penetrate the central nervous system, so most effects are respiratory in nature. An acetylcholinesterase, which has been carbamylated can undergo spontaneous hydrolysis in vivo, which reactivates the enzyme leading to less severe symptoms or a shorter duration of symptoms. Carbaryl has a low toxicity for mammals however, Perimicarb is highly toxic to mammals, but not readily absorbed through the skin. 

This chapter describes and compares the reported toxic effects of various types of organophosphate (OP) neurotoxicants on cell and tissue culture models (i.c., in vitro models), that represent the constituents of the central nervous system (CNS). Like several environmental neurotoxicants, OP compounds affect multiple cell types, employ various mechanisms of toxic action, produce sublethal functional impairment to cells at low concentrations, and are nonessential from a primary metabolic standpoint. Individual cells are the basic functional unit in which the toxic actions of chemicals can be deduced, and cell and tissue culture modcLs excel at providing controlled environments for exposing known cell types to toxicants and dircedy measuring their biological effects. 

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