OBJECTIVETo investigate the dynamic changes of neurofilament contents in rat's spinal cord induced by 2, 5-hexanedione (2, 5-HD), and explore the molecular mechanism of n-hexane neuropathy.

METHODSMale Wistar rats were administered at a dosage of 400 mg/kg/day 2, 5-HD for 2, 4 and 8 weeks respectively. HD-induced neurological defects were detected and quantified using gait score, and the relative lev-els of NF-H, NF-M, and NF-L in spinal cords of rats were determined by Western Blotting.

RESULTSExposure to 2, 5-HD produced progressive gait abnormalities, which suggested that the rat model of 2, 5-HD-induced neurotoxicity was established successfully. Western-Blotting results showed that NFs content in spinal cord demonstrated a progressive decline as the intoxication continued. In the supernatant fraction, compared to the controls, NF-H con-tent decreased by 15.7%, 57.0%, and 58.0% respectively after 2, 4, and 8-week treatment with 2, 5-HD (P < 0.01); accordingly, NF-M decreased by 36.0%, 61.3%, and 65.2% respectively (P < 0.01); NF-L decreased by 20.8%, 43.9%, and 44.3% respectively (P < 0.01). In the pellet fraction, the contents of NF-H in groups of 4 and 8 weeks' exposure to HD decreased by 35.6% and 43.2%, respectively (P < 0.01), and those of NF-L decreased by 26.4% and 42.1%, respectively (P < 0.01) when compared to the control. Further-more, NF-M contents in groups of 2, 4 and 8 weeks' exposure decreased by 23.3%, 33.9%, and 63.7% respectively (P < 0.01). The NFs level in spinal cords was highly correlated with gait abnormality of treated rats as the intoxication went on. Multiple correlation coefficients of NF-H, NF-M, and NF-L content with gait score of HD-treated rat were 0.8912, 0.9282 and 0.8981 (P < 0.01) respectively.

CONCLUSIONThe declines of NFs are high-ly related to neurobehavioral abnormality of 2, 5-HD-treated animals, and involved in the development of n-hexane neuropathy.