帕金森病大鼠发病过程中黑质神经元的缺失形式

Loss of substantia nigra neurons in Parkinson disease rats

目的:帕金森病最终都表现为患者中脑黑质多巴胺能神经元缺失,观察帕金森病发病过程中黑质神经元的缺失形式。方法:实验于2003-05/12在北京市神经外科研究所完成。取SD大鼠25只,按随机数字表法分为2组:①帕金森病模型组大鼠(n=21)立体定向下于右侧内侧前脑束区注射6-羟多巴(2g/L),术后皮下注射阿扑吗啡05mg/kg诱导旋转行为,大于7r/min视为成功偏侧帕金森病大鼠模型。②对照组大鼠(n=4)注射等剂量含0.2g/L抗坏血酸的生理盐水。分别于术后7d,2周、4周随机抽取帕金森病模型组大鼠(n=7)处死,取中脑组织切片进行Nissl染色,检测切片黑质致密区灰度值;应用DNA原位末端标记技术检测凋亡细胞,并与对照组对比。结果:死亡大鼠作随机补充,进入结果分析仍为25只大鼠。①实验成功复制出21只符合临床特点的帕金森病大鼠模型,多数大鼠于术后一两周出现旋转行为,2周时达到高峰,显著高于术后3,7d[(13.83±2.69,2.67±1.00,9.33±4.07)r/min(P<0.05)]。②术后7d,2周、4周模型组大鼠损毁侧黑质致密区的灰度值分别为149.50±13.14,117.29±10.62,110.41±17.34,均显著低于对照组(169.56±7.13)(P<0.05),模型2周组显著低于模型7d组(P<0.05)。③模型组大鼠术后2周的凋亡细胞最多,显著高于术后7d和4周组(3.60±0.27,3.07±0.39,2.27±0.43,P<0.05)。对照组未见到明显凋亡细胞。结论:6-羟多巴诱导的帕金森病大鼠损毁侧中脑组织黑质致密区中存在多巴胺能神经元凋亡,细胞凋亡在帕金森发病中可能起关键作用。

AIM： To investigate the pattern of neural loss in the compact part of substantia nigra （SNC） during the development of Parkinson disease （PD）, and the loss of SNc neurons is the ultimate manifestation of PD. METHODS： The experiment was done from May to December of 2003 in the Beijing Institute of Neurosurgery. Twenty-five SD rats were divided into 2 groups at random： （1）PD model group （n =21）： 6-hydroxydopamine （6-OHDA, 2 g/L） was stereoscopically injected in the right side of the medial forebrain bundle of the rats. The revolving behavior of rats were induced by the administration of 0.5 mg/kg apomorphine after operation, PD model was defined as a success if the revolving was over 7 r/rain. （2）Blank control group （n =4）： Rats were injected with equal volume of physiologic saline containing 0.2 g/L ascorbic acid. Rats of PD models were killed at the 7= day, 14= day and 28= day postoperatively, seven rats for each time. The grey value of brain section in SNc was estimated by Nissl dyeing. TdT-mediated dUTP-biotin nick end labeling technique was used to detect apoptotic cell. RESULTS： Twenty-five rats after the supplement were involved in the result analysis.（1）Twenty-one PD rat models were made successfully. The frequency of revolving behaviors reached peak at the 2^nd week, followed by that of the 3^rd and 7= days [（13.83±2.69, 2.67±1.00, 9.33±4.07） r/rain, P〈 0.05].（2）At the 7= day, 2^nd week, and 4= week postoperatively, the grey value of SNc was significantly lower in PD rats than in control group （149.50±13.14, 117.29±10.62, 110.41±17.34; 169.56±7.13, P〈 0.05）, and lower at the 2nd week than at the 7= day in PD rats （P〈 0.05）. （3）Apoptosis was found to peak within 2 weeks after treatment, which was significantly higher than that of the 7= day and 4= week postoperatively （3.60±0.27, 3.07±0.39, 2.27±0.43, P〈 0.05）. NO obvious cell apoptosis was present in the control group. CONCLUSION： The apoptosis can be found in SNc neurons in 6-OHDA induced PD model rats, and it may play a crucial role in the development of PD.