Effect of Tolbutamide on the Metabolism of Parathion

Abstract

Effect of the pretreatment with tolbutamide in female rats on the liver microsomal activation (anticholinesterase activities) and degradation (formation of p-nitrophenol) of parathion was studied. Both pathways were stimulated by tolbutamide-pretreatment, but the degradation process was superior to the activation of parathion at lower concentration of substrate in the liver preparation of rats pretreated with tolbutamide. The formation of p-nitrophenol from paraoxon by liver homogenate was also accerelated by tolbutamide. These facts should be reflected in the lowering of parathion toxicity in animals pretreated with tolbutamide.