Tyrosine의 유도체인 [$^{123}I$]IMT를 각종 악성종양의 SPECT에 이용하기 위하여 표지시 반응조건과 뇌종양이식 백서에서의 체내 동태를 연구하여 다음과 같은 결과를 얻었다. AMT의 [$^{123}I$] 표지에 chloramine-T 보다 Iodobead를 이용하는 것이 훨씬 간편하고 수율이 높았으며, Iodobead 1개, AMT $200{mu}g/100{mu}L$ phosphate buffer, PH 5.5, 상온에서 7분간 반응시키는 것이 최적 반응조건이었다. 9L glioma 이식 백서 체내동태는 [$^{123}I$]IMT가 신장으로 배설됨과 체내에서 탈요오드 반응이 일어남이 추측되었고, 정상조직의 3배 방사능 섭취가 관찰되어, 각종 뇌종양의 진단 및 치료 후 경과 관찰에 이용 가능성이 보여 임상연구의 진행이 기대된다.
L-3-[$^{123}I$]iodo-${alpha}$-methyltyrosine([$^{123}I$] IMT) was synthesized by electrophilic radio-iodination using chloramine-T and Iodobead in phosphate buffered solution. And the biodistribution was examined in 9L glioma bearing rats. The radiosynthesis of [$^{123}I$]IMT with iodobead was simpler and higher in radiochemical yield(88%) than the method using chloramine-T(83%) as radioiodinating reagent. The highest yield was obtained from the reaction using 1 piece of Iodobead, $200{mu}g$ ${alpha}$-methyltyrosine in $100{mu}l$ phosphate-buffered solution(pH 5.5) and the reaction was completed in 7min. 24 hours after the injection, the biodistribution in 9L glioma transplanted rats revealed the in vivo deiodination, the excretion via kidney, and 3 times higher uptake in the tumor than normal brain. These results suggest the promising clinical use of [$^{123}I$] IMT in the various malignancies.
