Human paraoxonase 1 hydrolysis of nanomolar chlorpyrifos-oxon concentrations is unaffected by phenotype or Q192R genotype.

ABSTRACT: The organophosphorus insecticide chlorpyrifos has been widely used. Its active metabolite chlorpyrifos-oxon (CPO) is a potent anticholinesterase and is detoxified by paraoxonase 1 (PON1). PON1 activity is influenced by numerous factors including a Q192R polymorphism. Using forty human blood samples bearing homozygous genotypes and either high or low activity phenotypes (as determined by high concentration assays of paraoxon and diazoxon hydrolysis) the serum PON1 hydrolysis of high (320 μM) and low (178 nM) CPO concentrations was assessed using direct or indirect spectrophotometric methods, respectively. PON1 activity at high CPO concentration reflected the phenotype and genotype differences; subjects with the high activity phenotype and homozygous for the PON1R192 alloform hydrolyzed sign

SUBMITTER: Coombes RH 

PROVIDER: S-EPMC4817274 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature