Send to

Choose Destination
See comment in PubMed Commons below
Neurotoxicology. 1981 Jan;2(1):13-24.

Pyridoxine megavitaminosis produces degeneration of peripheral sensory neurons (sensory neuronopathy) in the dog.

Author information

Ciba-Geigy Limited, Basle, Switzerland.


Pyridoxine, a water-soluble vitamin, produces a sensory neuronopathy when administered in high doses to dogs. Beagles who received a daily oral dose of 300 mg/kg of pyridoxol hydrochloride developed a swaying gait within 9 days. They eventually became unable to walk, but were not weak. Animals were sacrificed at intervals up to 78 days. Morphological examination revealed widespread neuronal degeneration in the dorsal root ganglia and the Gasserian ganglia. Cytoplasmic changes were first observed after 8 days and consisted of small, electronlucent vacuoles that subsequently coalesced leading to death of the cells. Degeneration of sensory nerve fibers in peripheral nerves, dorsal columns of the spinal cord and the descending spinal tract of the trigeminal nerve was apparent. The pathogenesis of these changes is unclear, but may, in part, reflect the selective permeability of blood vessels in the peripheral ganglia. It is apparent that the peripheral neuropathy previously attributed to pyridoxine actually represents a toxic, peripheral sensory neuronopathy.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center