Changes of n-hexane neurotoxicity and its urinary metabolites by long-term co-exposure with MEK or toluene.

摘要: It is well known that the neurotoxicity of n-hexane may be modified upon co-exposure with other organic solvents. In order to elucidate this mechanism further, rats were exposed 500ppm n-hexane, plus methyl ethyl ketone (MEK), toluene, or air only for 8h per day 33 weeks. The body weight, motor nerve conduction velocity (MCV) and distal latency (DL) determined before exposure after 4, 8, 12, 16, 20, 24, 29, weeks exposure. From each group one rat was histologically examined To establish a relationship between changes in biotransformation, urinary metabolites (2-hexanol, n-butyl (MBK), 2,5-hexanedione, 2,5-dimethylfuran, γ-valerolactone) measured by gas chromatography on first day, 1, 2, total amounts urine significantly decreased MEK as comparison those animals alone. 2,5-Hexanedione, which considered ultimate neurotoxic metabolite also decreased. Electrophysiological histological studies did not reveal statistically significant differences any two groups among four groups. present results might explain combined effects toluene decrease neurotoxicity, but do MEK. Therefore, mechanisms should studied.