Extremely sensitive biomarker of acute organophosphorus insecticide exposure

Hum Exp Toxicol. 2005 Jun;24(6):333-6. doi: 10.1191/0960327105ht532oa.


Egasyn-beta-glucuronidase complex is located at the luminal site of liver microsomal endoplasmic reticulum. When organophosphorus insecticides (OP) are incorporated into the liver microsomes, they become tightly bound to egasyn, a carboxylesterase isozyme, and subsequently, beta-glucuronidase (BG) is dissociated and released into blood. Consequently, the increase in plasma BG activity becomes a good biomarker of OP exposure. Thus, the single administration of EPN (O-ethyl O-p-nitrophenylphenylphosphonothioate), acephate and chlorpyrifos increased plasma BG activity in approximately 100-fold the control level in rats. The increase in plasma BG activity after OP exposure is a much more sensitive biomarker of acute OP exposure than acetylcholinesterase (AChE) inhibition.

MeSH terms

  • Animals
  • Biomarkers / blood*
  • Chlorpyrifos / toxicity
  • Dose-Response Relationship, Drug
  • Glucuronidase / blood*
  • Glucuronidase / metabolism
  • Insecticides / toxicity*
  • Male
  • Microsomes, Liver / drug effects*
  • Microsomes, Liver / metabolism
  • Organophosphorus Compounds / toxicity*
  • Organothiophosphorus Compounds / toxicity
  • Phenylphosphonothioic Acid, 2-Ethyl 2-(4-Nitrophenyl) Ester / toxicity
  • Phosphoramides
  • Rats
  • Rats, Sprague-Dawley
  • Time Factors


  • Biomarkers
  • Insecticides
  • Organophosphorus Compounds
  • Organothiophosphorus Compounds
  • Phosphoramides
  • Phenylphosphonothioic Acid, 2-Ethyl 2-(4-Nitrophenyl) Ester
  • acephate
  • Glucuronidase
  • Chlorpyrifos