Selective Neuronal Damage Produced by beta-fluoroethylacetate Intoxication in Rat Brain

ABSTRACT

Beta-fluoroethylacetate has been extensively used as the rodenticide in Korea. In some patients with acute poisoning, beta-fluoroethylacetate caused cerebellar dysfunction as a single and persistent neurologic sequela after a period of an acute neurological disorder which is characterized by mental deterioration, seizures, and respiratory failure. But there has been no report of pathological findings to explain neurological deficit. We tried to verify the histologic changes of the central nervous systems in beta-fluoroethylacetate poisoned rats. Silver staining(Gallyas) was used to evaluate the histology. In acute intoxication experiment with LD50(7mg/Kg), beta-fluoroethylacetate elicited acute onset of consciousness deterioration, generalized tonic-clonic seizures and large amplitude tremulous activity involving whole body with full recovery after 24 hours. There was no discernible pathologic change in CNS in acutely poisoned rats. However, when poisoned with sublethal dose(5mg/Kg) daily for five days, a moderate degree of nerve cell degeneration was found selectively in dentate nucleus, Purkinie cell layer, vestibulo-cochlear nucleus and striatum. This change was not seen in hippocampus, cerebral cortex or cerebellar cortex. These findings were well correlated with the previous reports of selective pathology in human 5-FU intoxication cases. Our preliminary results suggest that beta-fluoroethylacetate, a kind of cellular metabolism inhibitor may induce selective neuropathology mainly involving cerebellar output pathway in rats.