^(99)Tc^m标记HYNIC-Anx13用于细胞凋亡显像的研究

HYNIC-Anx13 Labelled With ^(99)Tc^m for Imaging of Apoptosis

为探讨99Tcm标记的HYNIC-Anx13用于细胞凋亡显像的可能性,分别以N-[三(羟甲基)甲基]甘氨酸(Tricine),乙二胺-N,N’-二乙酸(EDDA)和EDDA/Tricine为协同配体,对经6-肼基烟酰基(HYNIC)修饰的膜联蛋白V(Annexin V)片段(HYNIC-Anx13)的99Tcm标记条件和主要影响因素进行了研究,并完成了HYNIC-Anx13的99Tcm标记物在正常小鼠体内的生物分布和大鼠细胞凋亡模型的显像实验。实验结果表明,标记物在反应溶液和小牛血清中较稳定,但在与半胱氨酸的竞争反应中及在生物体内的稳定性较差。生物分布实验及体内显像结果表明,99Tcm标记HYNIC-Anx13的血液清除较快,在体内主要经肾脏排泄;在模型组的靶器官中的放射性摄取明显高于对照组(p<0.05),但靶与非靶组织的放射性比值较低,细胞凋亡组织的显像图像不够理想。

In this report, the ^99Tc^m labelling of Annexin V fragment modified with HYNIC （HYNIC-Anxl3） using Tricine, EDDA or EDDA/Tricine as coligands was described, The effect of various factors on ^99Tc^m labelling was investigated. Biodistribution studies in normal mice and gamma imaging of apoptosis in rats induced by cyclophosphamide were performed. The labelled conjugates were stable in aqueous solution and serum solution in vitro, but they were not stable when challenged with cysteine and in vivo. ^99Tc^m labelled HYNIC-Anx13 showed rapid blood clearance and renal excretion. The uptake in target organs in model rats were significantly higher than those in control rats （p〈0.05）, but the T/NT ratios were relatively low. The imaging result indicated that ^99Tc^m-HYNIC-Anx13 may not be a promising agent for apoptotic imaging.