Inhibitory pattern of tissue esterases in rats fed dietary pirimiphos-methyl

J Environ Sci Health B. 1989 Oct;24(5):509-24. doi: 10.1080/03601238909372664.


Activities of Acetylcholinesterase (AChE) in brain and erythrocytes, pseudocholinesterase (PChE) in plasma and non-specific carboxylesterase (NSE) in brain, liver, plasma and kidney were assayed at weekly intervals in growing male rats fed dietary pirimiphos-methyl at dosages of 1000, and 1500 ppm for a period of 28 days. Significant inhibition of tissue esterases were observed at the end of 7 days at both the dosages and the enzyme activities remained markedly inhibited at subsequent intervals. Activities of all enzymes (excepting Brain AChE) returned to normal levels following a 7-day maintenance on the insecticide-free diet implicating that pirimiphos-methyl induced little or no permanent tissue damage. The results suggest that plasma NSE level may also serve as a sensitive indicator in monitoring OPI exposure.

MeSH terms

  • Animals
  • Body Weight / drug effects
  • Brain / enzymology
  • Butyrylcholinesterase / blood
  • Carboxylesterase
  • Carboxylic Ester Hydrolases / antagonists & inhibitors*
  • Carboxylic Ester Hydrolases / blood
  • Cholinesterase Inhibitors*
  • Diet
  • Eating / drug effects
  • Erythrocytes / enzymology
  • Insecticides / pharmacology*
  • Kidney / enzymology
  • Liver / enzymology
  • Male
  • Organothiophosphorus Compounds / pharmacology*
  • Rats


  • Cholinesterase Inhibitors
  • Insecticides
  • Organothiophosphorus Compounds
  • pirimiphos methyl
  • Carboxylic Ester Hydrolases
  • Carboxylesterase
  • Butyrylcholinesterase