CHANGES OF DOPAMINE RECEPTOR ACTIVITY IN CAUDALPUTAMEN OF PARKINSON DISEASE RAT MODEL / 解放军医学杂志

ABSTRACT

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.