脑瘤显像剂I-AMT的标记及动物实验

Preparation of an imaging agent for brain tumour-radioiodinated α-methyl-1-tyrosine(AMT) and its animal studies

探讨了α－甲基－１－酷氨酸（α－ｍｅｔｈｙｌ－ｌ－ｔｙｒｏｓｉｎｅ简称ＡＭＴ）的放射性碘标记、分离纯化方法及其在小白鼠体内的分布。结果显示：采用氯胺－Ｔ法或Ｉｏｄｏｇｅｎ法标记，其标记率最低为６０％，最高达８０％以上。采用ＳｅｐｈａｄｅｘＬＨ－２０柱层析分离Ｉ－ＡＭＴ，其放化纯度均大于９８％。Ｉ－ＡＭＴ从血中清除迅速，主要经肾脏排泄；静注给药后５、１５、３０、６０ｍｉｎ。

Radioiodinated AMT is a new positive imaging agent for brain tumour. In this paper, its radioiodination, purification, and biodistribution in mice is described. AMT was labelled with 125I/131I using either chloramine-T or iodogen method. The labelling rate was 60% to 80%. After column chromatography on sephadex LH-20, the radiochemical purity was greater than 98%. Animal experiments showed that 25I-AMT was eliminated from blood rapidly and was mainly excreted through kidney. 5, 15, 30, 60 minutes after tail vein injection, the radioactivities of brain tissue per gram was 4.14%, 2.50%, 2.13%, 1.24% of injection dose respectively.