The effect of 3-methylfuran inhalation exposure on the rat nasal cavity.

The acute inhalation toxicity of 3-methylfuran (3MF) was investigated in female CD/CR rats. Animals were killed 1, 3, 6, 9, 12, 15 and 30 days following a 1-h exposure to 148 mumol 3MF/1. Relatively selective 3MF-induced necrosis of the olfactory epithelium was seen at day 1 post exposure. Subsequent resolution of the acute olfactory necrosis was not complete and resulted in partial occlusive fibrosis of the nasal cavity as seen at 30 days. Pretreatment of the animals with piperonyl butoxide (PB) did not block 3MF-induced olfactory epithelial necrosis although it prevented Clara cell necrosis when given at a dose of 800 mg/kg intraperitoneally 1 h before exposure to 3MF.