黑质内注射脂多糖对不同年龄大鼠DA能神经元和小胶质细胞活性的影响

The effects of nigral lipopolysaccharide administration on dopaminergic dysfunction and glial cell activation in young and aged rats

目的探讨青年和老年大鼠黑质DA能(DA)神经元对脂多糖(LPS)所诱导的损伤作用的敏感性差异和对小胶质细胞活性的影响。方法采用立体定向技术向大鼠单侧黑质内注入LPS建立PD大鼠模型;采用免疫组化法观察黑质酪氨酸羟化酶(TH)阳性细胞和OX6阳性小胶质细胞变化;采用Fluoro-Jade B染色法检测黑质的变性神经元。结果黑质内注射LPS后,老年组大鼠黑质区TH阳性神经元数量较青年组明显减少(P<0.01);老年组大鼠黑质区Fluoro-Jade B阳性神经元明显多于青年组(P<0.01);青年组大鼠黑质部位的OX6阳性小胶质细胞主要是处在激活期的;而老年组大鼠黑质部位的OX6阳性小胶质细胞主要是活化期的(阿米巴样或巨噬细胞样)。结论老年大鼠的黑质DA能神经元对于LPS所诱导的损伤作用较青年大鼠更为敏感。

Objective To investigate the effects of nigral lipopolysaccharide （LPS） administration on dopaminergic dysfunction and glial cell activation in young and aged rats.Methods LPS was stereostatically injected into unilateral substantia nigra of rats.Immunohistochemistry was used to detect midbrain dopaminergic neurons and microglia.The degenerative neurons in the substantia nigra were detected by Fluoro-JadeB staining.Results The number of TH-positive cells in aged group rats decreased significantly after LPS treatment, compared with the young group rats. The number of Fluoro-Jade B-positive cells increased obviously（ P 〈0.01） in aged group.The OX6-positive microglia of aged group was ameboid form mainly.The OX6-positive microglia of the young group was slightly activated form mainly.Conclusions The dopaminergic neurons in the substantia nigra of aged group were more vulnerability than that in young group after nigral lipopolysaccharide （LPS） administration.