EFFECTS OF INHALATION OF CADMIUM ON THE RAT OLFACTORY SYSTEM - BEHAVIOR AND MORPHOLOGY

Effects of inhalation of cadmium on the rat olfactory system:Behavior and morphology. NEUROTOXICOL TERATOL 18(1) 89-98, 1996.-To investigate the effects of cadmium on olfaction, two separate studies were conduc ted in which male adult rats were exposed to CdO, via inhalation, for 5 h per day 5 days a week for 20 weeks. Target exposure values of 250 and 500 mu g/m(3) were measured at 200 and 325 mu g/m(3) for the low c oncentration in two experiments, and 550 and 660 mu g/m(3) for the hig h concentration. Prior to exposure, olfactory thresholds were obtained using a conditioned suppression technique. After 20 weeks of cadmium exposure, there was no evidence of anosmia in any of the rats nor were there any significant changes observed in olfactory thresholds. Altho ugh olfaction was not impaired, cadmium levels in the olfactory bulbs of exposed rats were significantly elevated compared to controls. Card iac and respiratory histopathology were observed at all exposure level s, but there was no evidence of nasal pathology related to exposure to cadmium. Failure of cadmium to produce olfactory dysfunction may be d ue to the protective effects of metallothionein and/or to the highly r esilient nature of the rodent olfactory system.