Neurotoxicity of furfuryl alcohol vapor in prolonged inhalation exposure.

Three-month-old male Wistar rats exposed intermittently (5 days weekly, 6 hr/day) to furfuryl alcohol vapor at 1 (25 ppm), 2 (50 ppm), or 4 mumol/liter (100 ppm) for 4 to 16 weeks were lighter than controls at the end of the experiment at the two higher concentration levels. Urinary furoic acid excretion was in a linear relationship to the exposure at the same time. Analysis for cerebellar creatine kinase showed increased activity in all groups throughout the experiment while succinate dehydrogenase activity decreased in a dose-dependent manner at later time points. Glial cell fractions isolated from cerebral hemispheres showed decreased succinate dehydrogenase activity while 2',3'-cyclic nucleotide 3'-phosphohydrolase activity increased at 4 mumol/liter for 16 weeks. This change was accompanied by decreased basic protein content of isolated myelin fractions. The results indicate that furfuryl alcohol, at fairly low vapor concentrations, may have significant mitochondrial effects in the brain which lead to glial cell degeneration and initiation of demyelination.