The relationship between dopamine D2 receptors and brain perfusion in hemi-parkinsonism rats was studied. Hemi-parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra(SN) an...The relationship between dopamine D2 receptors and brain perfusion in hemi-parkinsonism rats was studied. Hemi-parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra(SN) and ventral tegmental area(VTA), apomorphine (Apo) which could induced the successful model rat rotates toward the intact side was used to select the rats, 125I-IBZM ex-vivo autoradiography analysis and 99mTc-HM-PAO regional cerebral biodistribution were used to evaluate D2 receptors and cerebral blood flow. The HPLC-ECD were used to measure striatum DA and its metabolites content. The lesioned side striatum DA and its metabolites HVA DOPAC reduced significantly than that of the intact side and seudo-operated group, striatum/cerebellum 125I-IBZM uptake ratio was 8.04+-0.71 in lesioned side of hemi-parkinsonism rats, significantly increased compared with the intact side and the seudo-operated group(p <0.05), 30.11+-4.53% enhancement as compared to the intact side, and also show good correlation with 30 min Apo induced rotation numbers (r=0.98), the regional cerebral blood flow study didn’t show significant difference between bilateral brain cortex area(p >0.05). These results indicated that in the 6- OH-DA lesioned side DA content decreased significantly and an up-regulation of striatum D2 receptor binding sites was induced in hemi-parkinsonism rats, which showed good correlation with rotation behavior induced by Apo. Comparing with cerebral blood flow, D2 receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental bend-parkinsonism.展开更多
文摘The relationship between dopamine D2 receptors and brain perfusion in hemi-parkinsonism rats was studied. Hemi-parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra(SN) and ventral tegmental area(VTA), apomorphine (Apo) which could induced the successful model rat rotates toward the intact side was used to select the rats, 125I-IBZM ex-vivo autoradiography analysis and 99mTc-HM-PAO regional cerebral biodistribution were used to evaluate D2 receptors and cerebral blood flow. The HPLC-ECD were used to measure striatum DA and its metabolites content. The lesioned side striatum DA and its metabolites HVA DOPAC reduced significantly than that of the intact side and seudo-operated group, striatum/cerebellum 125I-IBZM uptake ratio was 8.04+-0.71 in lesioned side of hemi-parkinsonism rats, significantly increased compared with the intact side and the seudo-operated group(p <0.05), 30.11+-4.53% enhancement as compared to the intact side, and also show good correlation with 30 min Apo induced rotation numbers (r=0.98), the regional cerebral blood flow study didn’t show significant difference between bilateral brain cortex area(p >0.05). These results indicated that in the 6- OH-DA lesioned side DA content decreased significantly and an up-regulation of striatum D2 receptor binding sites was induced in hemi-parkinsonism rats, which showed good correlation with rotation behavior induced by Apo. Comparing with cerebral blood flow, D2 receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental bend-parkinsonism.
