左旋多巴对偏侧帕金森病大鼠纹状体多巴胺D2受体表达数及多巴胺含量的影响

 目的了解左旋多巴(L-dopa)在抗帕金森病(PD)治疗中对纹状体区多巴胺D₂受体表达数及多巴胺含量的影响。方法采用6-羟基多巴胺(6-OHDA)制备偏侧PD大鼠模型。用免疫组化染色法和高效液相色谱法分别检测PD模型大鼠在L-dopa100mg·kg^-1·dkg^-1)腹腔注射15d前后纹状体部位的多巴胺D₂受体表达数、多巴胺及其代谢物含量变化。结果与L-dopa治疗前组相比,L-dopa治疗后PD大鼠模型纹状体中D2受体阳性表达细胞数明显减少(P<0.01),而多巴胺和代谢物含量明显增高。结论偏侧PD大鼠模型损毁侧纹状体区多巴胺D₂受体因代偿作用出现明显上调,而L-dopa干预能很大程度逆转了这种上调作用。

Effects of L-dopa on cells expressing D2 receptors and level of dopamine transmitter in hemiparkinsonian rats

OBJECTIVE To investigate the effects of L-dopa on cells expressing D₂ receptors and level of dopamine transmitter in striatum in the treatment of Parkinson's disease (PD) . METHODS Hemiparkinsonian model was established on rats pretreated with 6-hydroxy-dopamine. The cells of expression of D₂ receptor and the level of dopamine transmitters in striatum were detected respectively by immunohisto-chemical staining and HPLC before and after introducing L-dopa (100 mg·kg_-1·d_-1,ip) to PD model for 15d.RESULTS Compared with before-treatment group, decreased significantly whereas the level of dopamine transmitter at the lesioned side striatum increased significantly after L-dopa intervention to PD model, the cells expressing D₂ receptor at the lesioned side striatum(P< 0.01). CONCLUSION The cells expressing of D₂ receptor are compensatively upregulated at the lesioned side striatum in hemiparkinsonian rats. However, this upregulative effect can be reversed by L-dopa intervention to a great extent.