The yolk sac membrane from hen eggs contains esterases that hydrolyze phenyl phenylacetate OpPA) and are sensitive to inhibition, both in vitro and in vivo, by many organophosphorus compounds and by eserine. These esterases are the principal proteins in the membrane which are phosphorylated by 3H-diisopropyl phosphorofluoridate. Inhibition of this mixture of PPA-hydrolyzing esterases in viuo do...

The fate and movement of the organophosphorus insecticide chlorpyrifos (CPY;CAS No.2921-88-2) and its metabolite chlorpyrifos-oxon (CPYO; CASNo.5598-15-2) determine exposures in terrestrial and aquatic environments.Detectable concentrations of the organophosphorus insecticide CPY in air, rain,snow and other environmental media have been measured in North America and other locations at considera...

Fatty acid amide hydrolase (FAAH) plays an important role in nerve function by regulating the action of endocannabinoids (e.g., anandamide) and hydrolyzing a sleep-inducing factor (oleamide). Several organophosphorus pesticides and related compounds are shown in this study to be more potent in vivo inhibitors of mouse brain FAAH than neuropathy target esterase (NTE), raising the question of the...

Enzyme sensor for organophosphorus insecticides organophosphorus hydrolase in a polymer membrane on a pH sensor is used to catalyse the hydrolysis of compounds with phoshate ester functionality. The detected [H+] change is proportional to the concentration of the phosphate ester insecticide. This is a good example of the use of an enzyme to give selectivity to a specific class of compounds. Unf...

Organophosphorus and carbamate insecticides are toxic to insects and mammals by virtue of their ability to inactivate the enzyme acetylcholinesterase. This review addresses the mechanism of inhibition of acetylcholinesterase by organophosphorus and carbamate esters, focusing on structural requirements necessary for anticholinesterase activity. The inhibition of acetylcholinesterase by these com...