Effect of acute acrylonitrile exposure on metrazol induced seizures in the rat

The effects of acute exposure to acrylonitrile (ACN), 10, 20, or 40 mg/kg by gavage, on the ability of metrazol (MTZ) to induce seizures was studied in adult, male Sprague-Dawley rats. The frequency of seizure occurrence and the frequency of a lethal seizure was greater when the high ACN dosage was given in combination with metrazol. This dosage of ACN was not lethal when given alone. Examination of brain tissue in these animals revealed no difference in cyanide levels when MTZ was combined with ACN. However, brain cytochrome c was significantly lower in animals given ACN + MTZ and brain cholinesterase was significantly higher. These results suggest that the enhanced lethality occurring in animals exposed to the combination of ACN + MTZ is not due to cyanide, a metabolic product of ACN, but rather to a potentiation of other effects of ACN perhaps involving cholinergic neurotransmission.