6-OHDA制备的帕金森病大鼠黑质神经元的超微结构改变

ULTRASTRUCTURAL CHANGES OF DOPAMINERGIC NEURONS IN SUBSTANTIA NIGRA OF THE UNILATERAL 6-OHDA-TREATED RAT MODEL OF PARKINSON’S DISEASE

目的观察6-羟多巴胺(6-OHDA)单侧注射制备的帕金森病(PD)大鼠多巴胺(DA)能神经元的超微结构改变。方法单侧微量注射6-OHDA制备PD大鼠模型,用免疫荧光组织化学方法观察正常侧与6-OHDA注射侧黑质酪氨酸羟化酶(TH)阳性神经细胞及神经纤维的变化;并利用免疫电镜技术观察大鼠正常侧与注射侧黑质致密部DA能神经元的超微结构。结果免疫荧光法显示注射侧黑质致密部TH阳性细胞数和网状部TH阳性纤维面积与正常侧的百分比平均值分别为21.83%,23.19%。免疫电镜显示:TH免疫反应阳性产物表达于PD大鼠正常侧DA能神经元的高尔基复合体质膜面及胞质内,电子密度较高,注射侧很少见或几乎未见,且注射侧线粒体嵴有不同程度的溶解,呈空泡样变或髓样变,粗面内质网脱颗粒。结论6-OHDA可引起DA能神经元发生凋亡的超微结构改变。

Objective To observe the morphologic changes of dopaminergic neurons in the substantia nigra of Parkinson＇s disease （PD） rats that received a unilateral injection of 6-hydroxydopamine （6-OH- DA）. 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 TH in the nigra were detected by immuohistochemical method and measured with image analysis technique. The ultrastructural changes of nigra dopaminergic neurons of both the normal and the 6-OHDA injected sides of PD rats were observed by transmission electron microscopy. Results The average percent of TH immunoreactive cells and the area of TH immunoreactive fibers in the SN of the injected side were 21.83% and 23. 19% compared with that of the normal side. Under the electron microscope, TH immunoreactive products with high electron-density were located on the membrane of Golgi apparatus and the cytoplasm of TH positive cells. More immunoreactive prod- ucts were found in the normal side, but only little in the 6-OHDA injected side. Mitochondria showed vacuolar and myelonic degeneration, and rough endoplasmic reticulum lacked granules in the 6-OHDA injected side. Conclusion 6-OHDA can result in the apoptotic ultrastructural changes of the nigra dopaminergy.