Effects of long-term low-dose cyanide administration to rats

Chronic exposure to cyanide has been associated with development of pancreatic diabetes, hypothyroidism, and several neurological diseases in both humans and animals. However, there is a limited number of experimental models for these pathologies. Thus, in the present study 0, 0.15, 0.3, or 0.6 mg KCN/kg body weight/day was administered for 3 months to 26 rats. On the last day, plasma samples were obtained for glucose, cholesterol, and thyroidal hormone measurement, and the pancreas, thyroids, and whole central nervous system were collected for histopathologic study. There were no significant difference in plasma concentrations of the substances measured between groups, and no lesions were found in the pancrease or thyroid. The CNS of experimental animals revealed the presence of spheroids on the ventral horn of the spinal cord, neuron loss in the hippocampus, damaged Purkinje cells, and loss of cerebellar white matter. In conclusion, cyanide administration could promote neuropathological lesions in rats without affecting pancreas or thyroid gland metabolism.