帕金森病大鼠模型尾壳核多巴胺受体活性的变化

在建立6－羟多巴胺损伤的帕金森病大鼠模型基础上，应用放射配基结合方法及Scanchard作图，测定不同时间点模型鼠及对照鼠尾壳核多巴胺D1和D2受体的受体最大结合容量（Bmax）和平衡解离常数（KD）。结果显示，模型鼠毁损侧尾壳多巴胺D2受体Bmax显著升高，KD值显著降低，在1个月模型组达到高峰。D1受体除了2周模型组Bmax轻度升高，KD值轻度降低小，与对照组比较无差异。表明帕金森病模型鼠毁损侧尾壳核存在D2受体上行调节，受体亲合力增高，D1受体活性无明显变化。

CHANGES OF DOPAMINE RECEPTOR ACTIVITY IN CAUDALPUTAMEN OF PARKINSON DISEASE RAT MODEL

To explore the role and changes of dopamine receptor activity and their subtypes during the onset process of Parkinson disease( PD ), on the basis of 6 hydroxydopamine lesioned PD rat model, radioligand binding assay (RLBA) and Scanchard drawing were used to measure the maximal binding capacity of receptor (Bmax) and equilibrium dissociation constant (KD) of D 1 and D 2 dopamine receptors in caudal putamen of the model and control rats at different time point. The results of RLBA study revealed D 2 dopamine receptor Bmax was significantly increased and KD was significantly decreased in the caudal putamen ipsilateral to the lesion in rat model, and the changes reached the peak in one month rat model group. In contrast, the caudal putamen D 1 receptors were far less affected, with no consistent changes in the same model groups as compared with the control, except that 2 weeks model group showed Bmax was slightly decreased while KD was slightly increased. The study confirms that D 2 dopamine receptor is upregulated in the caudal putamen ipsilateral to the lesion in PD rat model, and the affinity of the receptors is increased, but the activity of D 1 dopamine receptor is not significantly changed.