Toxicokinetics monooxygenases

Resistance mechanisms associated with changes in toxicokinetics are predominately cases of enhanced metabolic detoxication. With readily biodegradable insecticides such as pyrethroids and carbamates, enhanced detoxication by P450-based monooxygenase is a common resistance mechanism (see Table 4.3). 

Boon, J.P., Van Arnhem, E., and Jansen, S. et al. (1992). The toxicokinetics of PCBs in marine mammals with special reference to possible interactions of individual congeners with cytochrome P450 dependent monooxygenase systems an overview. In C.H Walker and D. Livingstone (1992). Persistent Pollutants in Marine Ecosystems 119-160. 

Toxicokinetic and enzyme inhibition studies have established that aldicarb can readily bioactivate in most organisms into aldicarb sulfoxide and sulfone, which are more potent inhibitors of acetylcholinesterase. These metabolites may further convert into oximes and nitriles, all of which may be excreted out mostly in the urine. Studies in cows have shown that about 90% of aldicarb eliminated out within 24 -honrs through urine, exhaled air and milk. Stndies in fish indicate that both the cytochrome P450 and flavin monooxygenase systems are involved in bioactivation of aldicarb to its snlfoxide (Perkins, Jr. and Schlenk 2000). 

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