免疫介导豚鼠脊髓运动神经元损伤的超微结构及钙稳衡改变

Observation on ultrastructure and altered calcium homeostasis in the immune-mediated spinal cord motor neuron injury in guinea pigs

应用常规透射电镜及草酸盐-焦亚锑酸盐技术原位固定细胞内钙,对豚鼠脊髓前角细胞内的钙分布进行超微定位,探讨钙稳衡改变在免疫介导运动神经元损伤中的作用。结果发现模型组豚鼠脊髓前角运动神经元可见粗面内质网扩张、线粒体肿胀、嵴排列紊乱等。神经元周围胶质细胞增生。在运动神经元扩张的粗面内质网池和线粒体内室可见数量不等颗粒状电子致密的钙沉积物。线粒体内室内钙沉积颗粒与线粒体肿胀的程度相关。星形胶质细胞内肿胀的线粒体内室及扩张的粗面内质网池内也可见电子致密钙沉积颗粒。因此认为,钙稳衡失调参与了免疫介导的运动神经元损伤过程。

We examined the ultrastroctural changes and distribution of calcium in motor neurons of spinal cord anterior horn of guinea pigs using transmission electron microscopy and oxalate-pyroantimonate technique for calcium fixation. In the model group, dilation of rough endoplasmic reticulum, swelling and disturbance of cristae in mitochondria were observed in anterior horn motor neurons. Gliosis around motor neurons was seen. Electron-dense granular calcium depositions in different number were observed in dilated cisternae of rough endoplasmic reticulum, and vacuolated mitochondria. Calcium deposits in mitochondria were mainly concentrated in the inner chamber, and correlated with the swelling degree of mitochondria. Similar but less calcium deposits were observed in astrocytes. In conclusion, altered calcium homeostasis may involve in the spinal cord moor neuron injury in immune-mediated animal model.