左旋多巴对偏侧帕金森病大鼠纹状体多巴胺D_2受体表达数及多巴胺含量的影响

Effects of L-dopa on cells expressing D_2 receptors and level of dopamine transmitter in hemiparkinsonian rats

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·d-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。

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-hydroxydopamine, The cells of expression of D2 receptor and the level of dopamine transmitters in striatum were detected respectively by immunohistochemical staining and HPLC before and after introducing L-dopa （ 100 mg·kg^-1·d^-1, ip） to PD model for 15 d. 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.