Refining an Alternative to the EPA's Hen Test for OPs

EPA Grant Number: R825356
Title: Refining an Alternative to the EPA's Hen Test for OPs
Investigators: Ehrich, Marion , Jortner, Bernard S.
Institution: Virginia Polytechnic Institute and State University
EPA Project Officer: Hahn, Intaek
Project Period: November 7, 1996 through November 6, 1999 (Extended to November 6, 2000)
Project Amount: $357,572
RFA: Exploratory Research - Human Health (1996) RFA Text |  Recipients Lists
Research Category: Health Effects , Human Health , Health


An in vitro alternative to the hen test, required by the EPA for organophosphorus compounds (OPs) by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), is being developed. We found that neuroblastoma cells of human origin contain the same biochemical targets for OPs that are in the hen (i.e., acetylcholinesterase (AChE) and neuropathy target esterase (NTE, neurotoxic esterase)), and that concentration-related inhibition of AChE and NTE in these cells distinguish active OPs more likely to cause acute cholinergic crisis from OPs with potential to caused delayed neuropathy (OPIDN). To replace the hen test, protocols are under development to provide results equivalent to those obtained when hens are used. The objectives are to: 1) add a means for activation (oxidation) of protoxicant phosphorothionates to active esterase inhibitors in the cell culture system; 2) develop a protocol that would permit multiple exposure to Ops; and 3) provide a means for neuropathological evaluation of in vitro systems, as neuropathological examination is required for testing of OPs under FIFRA to verify OPIDN suggested by NTE inhibition. Therefore, time- and concentration-related cellular morphological alterations and associated changes in the dynamics of a variety of neuronal and cell stress proteins are being evaluated in human neuroblastoma cells and in chick reaggregate cultures. These data are to be correlated with NTE inhibition and compared to results in the hen model. Results of the work proposed could be used by the EPA to meet a mandate requesting federal agencies to reduce the number of animals used for toxicity testing and still allow the agency to provide effefctive regulations based on sound science.

Publications and Presentations:

Publications have been submitted on this project: View all 20 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 3 journal articles for this project

Supplemental Keywords:

organophosphorous, FIFRA, toxicity, test, human, air, Health, Scientific Discipline, Health Risk Assessment, Risk Assessments, ecological risk assessment, neurotoxic, multiple acute exposure, neuroblastoma cells, organophosphorous, animal model, developmental effects, human exposure, NTE, EPA's hen test, biomarker, cell stress proteins

Progress and Final Reports:

  • 1997
  • 1998
  • 1999 Progress Report
  • Final Report