Effect of Subchronic 3-Monochloro-1,2-propanediol Exposure on the Expression of Inducible Nitric Oxide Synthase in Rat Brain

3-Monochloro-1,2-propanediol (3-MCPD) is a contaminant of acid-hydrolyzed vegetable protein. Several reports have suggested that chronic exposure to 3-MCPD could produce neurotoxicity in vitro or neurobehavioral effects inaspects of experimental animals. Disturbance of the nitric oxide signaling pathway by chronic exposure to 3-MCPD may be a causal factor of neurological disorders in rats. In order to investigate the relationship between 3-MCPD administration and expression of inducibal nitric oxide synthase (iNOS), the numbers and distribution patterns of iNOS-immunoreactive neurons were examined. At the all three bregma level examined, the optical density of iNOS-postive neurons was significantly increased following exposure to 3-MCPD. The change was more severe in the upper layer than in deep layer of the cortex. These data suggest that 3-MCPD toxicity may be mediated through disturbances to the nitric oxide signaling pathway.