6-羟基多巴胺诱发大鼠黑质细胞凋亡的实验研究

6-ODPH-Induced Rat Nigral Apoptosis

目的 :为了解证实细胞凋亡参与了帕金森病 (Parkinsondisease,PD)的发病和黑质细胞凋亡的调控因素。方法 :通过脑立体定位注射 6 羟基多巴胺 (6 OHDA)建立大鼠PD模型。采用TUNEL法、原位杂交技术、电镜观察等 ,选择 6 DHDA注射术后 1、3、5、7、14及 2 1d为研究时点 ,观察大鼠PD模型形成过程中黑质细胞凋亡的数量及超微结构变化情况 ,并检测黑质细胞Bcl 2mRNA、P5 3mRNA表达情况及铁的浓度。结果 :用TUNEL法发现黑质细胞存在细胞凋亡 ,与对照组比较差异有显著性 (P <0 .0 5 ) ,7d细胞凋亡数为最高 ,2 1d最低 ;电镜观察在此过程中黑质细胞存在典型的细胞凋亡 ,并逐渐加重 ;Bcl 2和铁随时间增加而升高 ,P5 3则在 1d为最高 ,其后很快下降 ,但都高于对照组 (P <0 .0 5 )。结论 :6 OHDA能诱发大鼠黑质细胞凋亡 ,细胞凋亡参与了PD发病 ,并受到Bcl 2、P5 3和铁的影响。

Objective: To investigate the role of apoptosis in the pathogenesis of Parkinson disease (PD) and the modulatory factors for nigral apoptosis. Methods: By stereotaxically injecting 6 hydroxydopamine (6 OHDA) into the right side of the mesencephic ventral tegmental area (VTA) and substantia nigra pars compacta (SNs) of rats, SD model was developed. TdT mediated biotinylated dUTP nick ending labeling method (TUNEL), in situ hybridization and electron microscopic techniques were applied to observe the number of nigral apoptosis and the changes in the ultrastructure during the development of rat SD model on the day 1, 3, 5, 7, 14 and 21 after 6 OHDA injection. The expression of Bcl 2 mRNA, P53 mRNA and the content of Fe were measured. Results: The number of substantia nigral apoptosis in the PD group was much more than that in the control group ( P < 0.05 ), maximized on the day 7 and minimized on the day 21. In the PD group, the ultrastructure of substantia nigra exhibited morphological characteristics of apoptosis and aggravated successively. Bcl 2 mRNA and Fe content were increased day by day. P53 mRNA attained the peak value promptly on the day 1, and then decreased rapidly. Both Bcl 2 mRNA and P53 mRNA expression levels in the PD groups were higher than those in the control group ( P < 0.05 ). Conclusion: Apoptosis of substantia nigral induced by 6 OHDA contributes to the pathogenesis of PD and is influenced by Bcl 2 mRNA and P53 mRNA.