Summary: | 碩士 === 國立陽明大學 === 生物醫學影像暨放射科學系 === 102 === Objective:The study synthesized a novel amino acid based radiotracer [131I]IET and evaluated its biological behavior in F98 glioma cell as a novel proliferation probe.
Methods:We synthesized an [18F]FET analogue and compare with the previous reported amino acid based probe [131I]IPA in F98 glioma cellular uptake. Chloramine-T as an oxidizing agent for the iodination of the phenol ring on the tyrosine and phenylalanine derivatives. In competitive inhibition studies, we use several amino acid transporter inhibitor for the inhibition and to study the uptake mechanism of [131I]IET.
Results:F98 cellular uptake demonstrate that although the uptake ratio of [131I]IET obviously less than the previous reported [131I]IPA, but has a surprising result compares to the [18F]FET. Suggest that [131I]IET might be useful in glioma imaging other than [18F]FET. In competitive inhibition studies, after pretreatment of BCH,the uptake of F98 glioma reduced 56%. And for the system A inhibitor MeAIB, the uptake of F98 glioma reduced 30%. Pretreatment of system ASC and system B+,0 inhibitor, the uptake reduced 57% and 55% as well. Suggest that [131I]IET might not be transport in to cells through a specific transporter.
Couclusion:In this study, we use [18F]FET as a template to modify an iodine labeled tyrosine derivatives. Chloramine-T as an oxidizing agent to afford [131I]IET and [131I]IPA. In F98 cellular uptake, [131I]IET has higher uptake ratio than [18F]FET. And due to the amino acid enter and exit the cell in an average rate, the uptake kinetics become stable after incubate the tracer in 5 minutes. The competitive inhibition studies suggest [131I]IET might be passing through the cell with System L、ASC and B+,0. In a nutshell, [131I]IET might be a promising glioma imaging agent, but the transport mechanism of [131I]IET needs further investigation.
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