Chronic low-dose exposure of sodium nitrite in VM-strain mice: central nervous system changes

1. There is suggestive evidence that nitrite may be a causative factor in cerebral glioma. 2. To test this hypothesis we selected the VM mouse strain, known for its susceptibility to spontaneous glioma formation, and exposed 300 animals to 0.2% sodium nitrite in their drinking water. One hundred of this group were exposed both in utero and throughout their adult lives. The remaining 200 animals received nitrite from the time of weaning. A further 200 mice were used as controls and received distilled water. 3. All animals were maintained until their natural death and were then subjected to autopsy and routine histological examination. 4. There was no excess of nervous system tumours in the experimental groups.