Fluoride Action Network


Introduction: Sodium fluoride (NaF) toxicity has been a subject of extensive studies over the last years because of their environmental persistence and world widespread distribution. Its toxicity on many organs has received considerable attention, but its neurotoxicity has not been entirely studied.

Aim of the Work: Studying the histological changes occurring in the cerebellar cortex of albino rats following chronic exposure to NaF and the possible protective role of vitamin B6.

Materials and Methods: Twenty adult male albino rats were divided into group I (control), group II (each animal was daily injected I P with 3.6 mg vitamin B6), group III (each animal received 10 mg/kg NaF orally once daily) and group IV (each rat was given vitamin B6 concomitantly with NaF at the same dose, period and route of group II and III). After three months the cerebellum was dissected and prepared for light and electron microscopic study.

Results: The cerebellum of NaF treated animals exhibited severe degenerative changes especially in Purkinje cells. There was multilayer disposition of these cells associated with structural changes in the form of dilated rER and Golgi complex, swollen mitochondria in addition to marginated nuclear chromatin. The surrounding neuropil appeared vacuolated with accumulation of neuroglial cells. Many myelinated nerve fibers displayed disruption in myelination and irregular neurofilaments. Silver stained sections showed accumulation of cytoskeletal elements in Purkinje cells. On the other side, these changes were ameliorated in rats of group IV which received vitamin B6 concomitantly with NaF.

Conclusion: Chronic administration of NaF induced degenerative changes in the cerebellar cortex which could be ameliorated by vitamin B6.