Taurine in the olfactory system: effects of the olfactory toxicant dichlobenil.

Following intranasal instillation of 14C-taurine in C57B1/6 mice, there was a labelling of the olfactory neuroepithelium, axon bundles and axon layers in the olfactory bulb 4 and 24 h later, suggesting an axonal migration of radioactivity to the olfactory bulbs. In the olfactory bulbs the level of radioactivity was 45-times higher than that in the posterior part of the brain. In mice treated with the olfactory toxicant dichlobenil, inducing necrosis in the dorsomedial olfactory region, there was a dose-dependent decrease in the level of 14C-taurine and 3H-carnosine (derived from the precursor 3H-beta-alanine) in the olfactory bulb. The migration of 14C-taurine in the olfactory system of dichlobenil-dosed mice gradually recovered 3 - 8 weeks later although an atypical epithelium remained in the dorsomedial portion of the olfactory region. The results suggest a transient reduction of the migration of taurine in the olfactory system of mice following chemically-induced toxicity at this site.