Superfund Research Program
Organophosphate Pesticide Exposure: Analysis of Disposition in the Body and Target Inactivation in Relation to Gene Expression
Project Leader: Palmer W. Taylor
Grant Number: P42ES010337
Funding Period: 2000-2010
Project Summary (2000-2005)
Cholinesterase inhibitors account for more than half the poisonings in California from home garden and agricultural use. Therefore, the widespread use of these agents in agriculture presents a major toxicity problem, typically from soil runoff following a rain storm. As a means of detecting cholinesterase inhibitors, this project is developing technologies using high titer antibodies and mass spectrometry to detect phosphorylated and unphosphorylated acetylcholinesterase. The symptoms and target of acute toxicity from cholinesterase inhibitors are well known, but the sites and precise mechanisms of chronic toxicity remain an enigma. Therefore, to correlate residual inhibition with long-term toxicity, investigators have developed cholinesterase inhibitors selective for the central and peripheral nervous systems. Variations in gene expression that arise from localized cholinesterase inhibition in the brain and periphery are being examined. Inhibition by these agents can be expected to result in overstimulation of cholinergic pathways leading to more prolonged alterations in gene expression. Microarray chips are being used to detect changes in localized gene expression in regional brain areas and periphery following exposure to the insecticides. Gene trap methods will identify exposure-sensitive genes in culture. Candidate genes, including some known to be responsible to cholinergic stimulation are the early immediate genes (c-jun and c-fos), several regulatory kinases (JNK, p38, and IKK), and various transcriptional factors (NF-kB, Egr-1, Egr-3, and the Wilms tumor gene). This project will also examine cholinesterase inhibitors in animals in which the responsive gene has been eliminated.