6-羟多巴胺制备的帕金森病大鼠脑内神经递质的变化

Changes of neurotransmitters in the brain of unilateral 6-OHDA-treated rat model with Parkinson disease

目的:研究6-羟多巴胺(6-OHDA)制备的帕金森病(PD)大鼠脑内神经递质的变化。方法:6-OHDA微量注射建立大鼠PD模型,免疫组织化学方法观测注射侧和正常侧黑质酪氨酸羟化酶(TH)、突触素(SYN)及纹状体内γ-氨基丁酸(GA-BA)的表达,利用免疫电镜技术观察黑质网状部突触的结构变化。结果:6-OHDA注射侧黑质致密部TH阳性细胞数、GA-BA阳性细胞数量、SYN阳性突触的面积及平均光密度值(D值)较正常侧均显著降低。免疫电镜观察SYN免疫反应产物定位于小圆形或扁形突触囊泡质膜面,电子密度高。正常侧可见密集的SYN免疫反应产物,清晰的突触结构,注射侧SYN免疫反应产物很少见,突触结构少见,结构模糊,线粒体肿胀、空泡样变。结论:6-OHDA制备的PD大鼠神经递质及突触结构发生了显著改变。

Objective： To investigate the changes of neurotransmitter in the brains of Parkinson disease （PD） rats that received a unilateral injection of 6-hydroxydopamine （6-OHDA）. Methods ： PD models were established by microinjection of 6- OHDA solution into the substantia nigra of the right side of the brain. The expressions of tyrosine hydroxylase （TH） and synaptophysin （SYN） in the substantia nigra and γ--aminobutyric acid （GABA） in striatum were detected by immuohistochemical method and measured with image analysis technique. Ultrastructural changes of the synapses in the pars reticulata of the substantia nigra （SNr） were observed. Results： Immunohistochemical studies showed that number of TH immunore- active ceils and the GABAergic neurons in the 6-OHDA injected side were reduced obviously compared with those in the nor- mal side. The area and the optical density （OD） values of SYN immunoreactive boutons in the SNr were also reduced signifi- cantly compared with those of the normal side. Using immunoelectronic microscopy, the SYN had been detected. More SYN immunoreactive products were found in the normal side, but only little in the 6-OHDA injected side. The structures of cell components were normal in the normal side. SYN immunoreactive products lied on the cytoplasm membrane of round or flat- tened synapse vesicles. In the 6-OHDA injected side, the structures of synapses were faint, and the mitochondria were ab- normal. Conclusion ： 6-OHDA can cause changes of some neurotransmitters and synapse structures.