氨对培养胚鼠大脑神经元形态的影响

Morphological effects of ammonia on cultured fetal rat neurons

为研究氨对培养神经元的影响，并探讨神经元形态改变在肝性脑病发生中的作用。通过对胚胎大鼠大脑神经元的分散培养，结合光镜，透射电镜及免疫组织化学法，观察了氨对分散培养胚鼠大脑神经细胞的影响，发现氨可引起神经元胞体肿胀，尼氏小体溶解，胞质内出现颗粒及空泡变性，甚至突起崩解，核固缩，细胞坏死脱落；电镜下示细胞内内质网，线粒体扩张及囊性变，粗面内质网脱颗粒，大量致密小体出现，突起肿胀，微丝减少；神经微丝蛋白及突触体素的表达减少。实验结果表明，氨对培养神经元具有一定毒性作用，神经元的病变可能影响了其正常功能，促使肝性脑病的发生。

The effects of ammonia on cultured fetal rat neurons and the possible relation between morphologic changes of neurons and the pathogenesis of hepatic encephalopathy were studied on dissociated fetal rat neuronal cultures, using light microscopy, transtnission electron microscopy and imrnunty histochemistry methods. The neurons exhibited cellular swelling, chromatolysis, vacuolization and granulation, followed by segmental enlargement and fragmentation of cellular processes, detachment of neurons with pyknotic nuclei. Electron microscopic examination displayed dilation of mitochondria and endoplasmic reticulum, degranulation of rough endoplasmic reticulum, accumulation of dense bodies to gether with swelling of the process with loss of neurofilaments. The expression of neurofilament and synaptophysin became weak and even negative. The data therefore suggests that amrnonia may exert a toxic effect on cultured neurons, disturbing their normal function and facilitating the developrnent of hepatic encephalopathy.