1-溴丙烷吸入染毒大鼠周围神经电生理及病理特点

Electrophysiological and pathological features of peripheral nerve in rats exposed to 1-bromopropane

目的探讨1-溴丙烷慢性吸入染毒对大鼠周围神经电生理及病理的影响。方法成年雄性sD大鼠40只，随机分为不同1．溴丙烷浓度染毒组和对照组，各组大鼠均置于动式吸入染毒柜内，分别给予吸入低浓度（1000mg／m3）、中浓度（2000mg/m3）、高浓度（4000mg／m3）1-溴丙烷和新鲜空气，每天6h，每周5d，连续12周，观察大鼠神经坐骨神经传导速度、肌电图及病理改变。结果高浓度染毒组大鼠体重明显低于对照组，差异有统计学意义（P〈0．05）。与对照组比较，中、高浓度染毒组运动神经传导速度、复合肌肉动作电位波幅降低，差异均有统计学意义（P〈0．05）。与对照组比较，高浓度染毒组感觉神经传导速度、感觉神经动作电位波幅均下降，差异有统计学意义（P〈0．05）。肌电图检查发现高浓度染毒组大鼠出现失神经支配改变。坐骨神经病理活检电镜观察发现，高浓度染毒组大鼠同时出现轴索变性和脱髓鞘改变。结论大鼠慢性吸入4000mg／m31-溴丙烷，可引起周围神经损害，同时出现轴索变性和脱髓鞘改变，以轴索损害为主。

Objective To study the electrophysiological changes and pathological characteristics of peripheral nerve in rats exposed to 1-bromopropane through chronic inhalation. Methods 40 male SD rats were randomed divided into 4 groups, and exposed to 1-bromopropane vapor at concentrations of 1 000 mg/m3, 2 000 mg/m3, 4 000 mg/m3 and fresh air respectively, 6 hours per day, 5 days per week for 12 weeks. The changes of nerve conduction velocity （NCV）, eleetromyography （EMG） and pathology were observed. Results After 4 weeks of exposure, the body weights of high dose group are lower than that of the control group. Compared with the control group, the high and medium dose group have a decline in MCV and CMAPs, while SCV and SNAPs descend in the high dose group （P〈0.05）. The EMG examination showed that there are denervation changes in high dose group. Sciatic nerve biopsy observed by electron microscope showed that axonal degeneration and demyelination coexist in the rats exposed to high concentration. Conclusion Chronic inhalation of 1- bromopropane at the concentration of 4 000 mg/m3 can cause peripheral nerve injury, which is characterized by axonal degeneration and demyelination. Axonal degeneration is the main pathological change.