【摘要】 目的研究凋亡显像剂⁹⁹Tc^m-人膜联蛋白V（Annexin V）的制备及其与多巴胺能神经元凋亡模型的体外结合特性。方法运用双功能螯合剂联肼尼克酰胺（HYNIC）进行⁹⁹Tc^m 标记 Annexin V,形成⁹⁹Tc^m-HYNIC-Annexin V,经 Sephadex G-25柱层析分离纯化,采用快速薄层层析（ITLC）法检测放化纯。将⁹⁹Tc^m-HYNIC-Annexin V 与经过1-甲基-4-苯基吡啶离子（MPP⁺）处理制模的大鼠肾上腺嗜铬细胞瘤PC12细胞进行体外细胞量及时间-温度结合实验、饱和结合实验和竞争结合实验.得到⁹⁹Tc^m-HYNIC-Annexin V 与多巴胺能神经元凋亡模型的结合特性,并比较其与正常细胞及不同凋亡水平下细胞模型的结合特性。结果①⁹⁹Tc^m-YNIC—Annexin V 标记率（64.56±6.23）%,比活度（3.7～74）×10⁵kBq/mg,放化纯（93.6±2.48）%,室温放置4 h 后放化纯仍大于90%。②⁹⁹Tc^m-HYNIC-Annexin V 与多巴胺能神经元凋亡模型的结合具有特异性、可饱和性,Scatchard 图示平衡解离常数（K_d）为（7.16±1.78）nmol/L,最大结合容量(B_max)为（178.73±32.62）fmol/10⁶细胞。结论多巴胺能神经元凋亡模型对⁹⁹Tc^m-HYNIC-Annexin V 有良好的摄取,可进一步行动物体内研究。更多还原

【Abstract】 Objective The aims of this study were two.One was to find out an optimal method for ⁹⁹Tc^m-Annexin V preparation and the other was to investigate the binding characteristics of ⁹⁹T^m-Annexin V in dopamiuergie apoptotic neurons in vitro.Methods For ⁹⁹Tc^m-Annexin V preparation,hydrazine nico- tinamide（HYNIC）,a bifunetional chelating agent was used.Product was purified by Sephadex G-25 col- umn chromatography and analyzed with instant thin layer chromatography（ITLC）.To test the binding char- acteristics in dopaminergic apoptotic neurons in vitro,a rat pheochromocytoma cell line（PC12）treated with 1-methyl-4-phenylpyridinium（MPP⁺）was used.Tests including time-temperature binding,saturable bind- ing,competition binding between dopaminergic apoptotic neurons and ⁹⁹Tc^m-HYNIC-Annexin V and dose- dependent MPP⁺ studies were performed and evaluated.Results The labeling rate of ⁹⁹Tc^m was（64.56± 6.23）%.The specific activity of ⁹⁹Tc^m-HYNIC-Annexin V was（3.7～74）×10⁵ kBq/mg protein.The ra- diochemical purity was（93.6±2.48）% and was>90% after 4 hours’ storage at room temperature.Scat- chard plotting suggested that the concentrations of K_d was（7.16±1.78）nmoL/L,and B_maxwas（178.73± 32.62）fmol/10⁶ cells.Conclusions The preliminary results show that an optimal ⁹⁹Tc^m-HYNIC-Anncxin V preparation method can be provided.The ⁹⁹Tc^m-HYNIC-Aunexin V prepared in our laboratory has good re- ceptor-binding activity and may possibly be a potential drug in studying the apoptotie phenomenon in Parkin- son’s disease at early stage in an animal model.更多还原