Comparative studies of D₂ receptors and brain perfusion in hemi-parkinsonism rats

Comparative studies of D 2 receptors and brain perfusion in hemi-parkinsonism rats 1 corresp first-author Corresponding address: LIN Yan-Song, M.D., (Now is the Postdoc Fellow in the National Laboratory of Nuclear Medicine, 20 Qian Rong Road, Wuxi, Jiangsu 214063 E-mail: jsinm@public1.wx.js.cn Corresponding address: LIN Yan-Song, M.D., (Now is the Postdoc Fellow in the National Laboratory of Nuclear Medicine, 20 Qian Rong Road, Wuxi, Jiangsu 214063 E-mail: jsinm@public1.wx.js.cn jsinm@public1.wx.js.cn 1 Huashan hospital, Shanghai Medical University, Shanghai 200040 Huashan hospital, Shanghai Medical University, Shanghai 200040 The relationship between dopamine D 2 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, 125 I-IBZM ex-vivo autoradiography analysis and 99m Tc-HM-PAO regional cerebral biodistribution were used to evaluate D 2 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 125 I-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 D 2 receptor binding sites was induced in hemi-parkinsonism rats, which showed good correlation with rotation behavior induced by Apo. Comparing with cerebral blood flow, D 2 receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental hemi-parkinsonism. Parkinsonism Receptors/dopamine D 2 Cerebral blood flow Autoradiography 125 I-IBZM 99m Tc-HM-PAO References Salmon E. Sadzot B , Maquet P et al . J Nucl Med , 1994 , 35 : 391 ~ 397 J Nucl Med Lin Y S. Lin X T , Zhang T Y et al . Nucl Tech (in Chinese) , 1996 , 9 : 641 ~ 644 Nucl Tech (in Chinese) Lin Y S , LIN X T . Chinese J Nucl Med . 1999 . 19 : 69 ~ 71 Chinese J Nucl Med Kung M P , Liu B L , Yang Y Y et al . J Nucl Med . 1991 , 32 : 339 ~ 342 J Nucl Med Leenders K L A , Antonini J , Schwarz K et al . Mov Disord 1992 , 17 ( suppl ): 141 ~ 145 Mov Disord Taylor A E , Saintlyr J A , Lang A E et al . Brain , 1986 , 109 : 845 ~ 849 Brain Luo J J . Foreign Medicine (Neurology part.) , 1992 , 19 : 261 ~ 262 Foreign Medicine (Neurology part.) Wang S J , Liu R S , Liu H C et al . Eur J Nucl Med 1993 , 20 : 339 ~ 341 Eur J Nucl Med Song W Z , Lin X T . Chin J Nucl Med (in Chinese) , 1991 . 11 : 18 ~ 19 Chin J Nucl Med (in Chinese) Chen S D , Zhou X D , Xu D L et al . Clinical Neuroscience . 1994 , 2 : 142 ~ 145 Clinical Neuroscience R741, R749.1, R817 2000-07-18 2000-11-01 2021-02-05 2000 Nuclear Science and Techniques 4 11