鱼藤酮灌胃制备帕金森病小鼠模型的评价及机制

目的探讨经持续鱼藤酮灌胃制备帕金森病小鼠模型及其发病机制。方法将50只老年雄性C57小鼠随机分为模型组和对照组，2组均给予连续灌胃12周，模型组予灌注0．01ml／g鱼藤酮氯仿溶液，对照组则予灌注0．01mg／g氯仿溶液。在灌胃前、灌胃6、12周时对2组小鼠行网格试验、爬杆试验和滚轴试验以检测行为学变化，使用高效液相色谱电化学法（HPLC-ECD）检测纹状体多巴胺（DA）、3，4-二羟基苯乙酸（DOPAC）、高香草酸（HVA）等神经递质浓度；对肠、胸段脊髓、中脑行α-突触核蛋白（α-Syn）、硫磺素S（ThS）、酪氨酸羟化酶（TH）等免疫组化染色。结果至灌胃12周时模型组行为学变化较对照组均有显著性差异（P〈0．01），模型组纹状体DA、DOPAC、HVA水平较对照组有显著性降低（P〈0．01）。灌胃6周时模型组小肠内、胸段脊髓处α-Syn的表达水平较对照组明显增加，且ThS表达比例增多，而中脑处a-Syn及TH阳性细胞数无显著性差异；至灌胃12周时模型组中脑处Syn的表达较对照组明显要增多，而TH阳性细胞数较对照组显著性减少（P〈0．05）。结论经持续鱼藤酮灌胃制备的慢性进展性帕金森病小鼠模型模拟了PD缓慢进展的病理过程，其机制可能是小肠神经丛局部的α-Syn多聚体通过类朊蛋白途径沿着神经传导通路播散至脑内。

Alterations and mechanisms of the Parkinson disease mouse model reproduced by intragastric administration of rotenone

Objective To explore alterations and mechanisms of the Parkinson disease mouse model reproduced by intragastric administration of rotenone. Methods 50 aged male mice were randomly divided into Parkinson disease （PD） model group and control group. The mice in PD model group were administrated 0. 01 ml/g rotenone by gavage while the mice in control group were administrated 0. 01 ml/g chloroform. Before treatment and after 6 weeks, 12 weeks treatment, the rotarod test, grid test, bar test were performed. Simultaneously, DA, DOPAC and HVA were detected by HPLC-ECD. Alpha-synuclein （α-Syn）, Thioflavin S （ThS） and tyrosine hydroxylase （TH） were detected in neurons from gastrointestinal tract, thoracic spinal cord and midbrain of both control and treated animals. Results After 12 weeks treatment, the behavioral tests showed there were significant difference between PD model group and control group. HPLC-ECD indicated that the levels of DA, DOPAC and HVA in PD model group are lower than in control group statistically. After 6 weeks treatment, immunofluorescence demonstrated that α-Syn and ThS increased in intestinal intramural plexus and thoracic spinal cord when compared to controls while an increase of α-Syn in midbrain was not observed. However, after 12 weeks treatment immunofluorescence showed that there was an increase in α-Syn and an decrease in TH positive neurons from midbrain. Conclusions Progression of Parkinson＇s disease pathology is reproduced by intragastric administration of rotenone in mice whose possible mechanisms is that synuclein aggregates might spread from gastrointestinal tract to brain by prion-like transmission.