甲基汞引发的大鼠脊髓前角大型运动神经元的脱落

目的研究有机汞中毒大鼠脊髓前角的病理学改变。方法使用每日１０ｍｇ／ｋｇ甲基汞，给成熟大鼠连续灌胃１０日，观察其脊髓、前根及肌肉的病理学所见。结果首次投药１４日起，脊髓前角大型运动神经元胞质内出现空胞及尼氏小体脱失；在１６日观察到噬节现象；到１８日，前角大型运动神经元高度脱落，而中、小型神经元则无明显减少。使用醋酸银金属自显影技术亦检测到脊髓前角大型运动神经元有汞的特异性沉积。结论以往报道的汞中毒性类肌萎缩侧索硬化综合征的主要病理学基础为脊髓前角运动神经元的变性、脱落，本实验动物模型可以作为研究运动神经元疾病病理生理学改变的有用模型。

Selective involvement of large motor neurons in the spinal cord of rats treated with methylmercury

Objective To elucidate the pathogenic change of spinal anterior horn in rats treated with methylmercury (MeHg).Methods We administered 10mg/kd/day MeHg to adult rats for 10 days,and observed the spinal anterior horn,anterior roots and muscles chronologycally.Results Light microscopically,large motor neurons in the spinal anterior horn showed cytoplasmic vacuolation and loss of nissl substance on the 14th day after starting MeHg,and neurophagia appeared on the 16th day.On the 18th day,almost complete loss of large motor neurons was observed.Conclusion It is considered that experimental MeHg intoxication could be a good tool for researches into the pathophysiology of human motor neuron disease.