ABSTRACT
OBJECTIVE: To observe the effect of n-hexane subchronic exposure on the serum level of neuron specific enolase(NSE), neurofilament light chain protein(NF-L) and nerve growth factor(NGF) in rat, and to explore the feasibility of using NSE, NF-L and NGF as biomarkers of n-hexane neurotoxicity. METHODS: Specific pathogen free male SD rats were randomly divided into control group and low-, medium-and high-dose exposure groups, with 6 rats in each group. Rats in the low-, medium-and high-dose exposure groups were given n-hexane solution at doses of 168, 675 and 2 700 mg/kg body mass, respectively, while rats in the control group were gavaged with 0.9% sodium chloride solution, once a day, 5 days a week for 6 weeks. At week 0, 2, 4, and 6 of exposure, the body mass of the rats was weighed, the gait scores were performed, and the serum levels of NSE, NF-L, and NGF were detected.RESULTS: Body mass, gait score and serum levels of NSE and NF-L in rats were statistically significant in terms of the n-hexane exposure dose and exposure time(P<0.01). At the 6 th week of n-hexane exposure, the body mass of the three dose exposure groups was lower than that of the control group(P<0.05), and the gait score was higher than that of the control group(P<0.05). Moreover, the abnormal gait of the rats showed a dose-effect relationship with the increasing n-hexane poisoning dose. At week 2, 4 and 6, the serum levels of NSE and NF-L in these three dose exposure groups were higher than that in the control group(P<0.05). In addition, the serum level of NF-L in rats in the medium-and high-dose exposure groups increased with the n-hexane exposure time increasing and showed a time-effect relationship(P<0.05). The level of serum NGF in rats was statistically significant in the main effects of n-hexane dose and duration of exposure(P<0.05). The serum NGF level in the high-dose exposure group was lower than that in the control group, the low-dose and medium-dose exposure groups(P<0.05). NGF level in serum of rats at week 6 was lower than that at week 0, 2 and 4(P<0.05). CONCLUSION: Both NSE and NF-L in serum can be used as biomarkers for the early effect of n-hexane on peripheral nerve injury. The feasibility of using serum NGF as a biomarker for the early effect of n-hexane on peripheral nerve injury warrants further investigation.