具有八個胺基酸的環型胜肽octreotide，是一種體抑素類似物，對體抑素受體具有高度親和力。本研究旨在發展99mTc(I)-HYNIC-octreotide為一種有效的體抑素受體造影劑。本研究參考核能研究所的方法，以固相胜肽合成法製備HYNIC-octreotide。並參考文獻方法合成HYNIC及[99mTc(CO)3(OH2)3]+。以[99mTc(CO)3(OH2)3]+為前驅物，於75℃及中性條件下進行標誌HYNIC-octreotide得99mTc(I)-HYNIC-octreotide。根據實驗結果得知[99mTc(CO)3(OH2)3]+標誌於HYNIC-octreotide標誌產率可達90%以上。HYNIC-octreotide在體抑素受體競爭實驗中，有效地抑制125I-Tyr11-Somatostatin的結合，證實HYNIC-octreotide具有對體抑素受體的結合能力。經由活體動物實驗，注入99mTc(I)-HYNIC-octreotide於種有AR42J腫瘤之SCID小鼠，其腫瘤位置顯現清楚並且持續累積的影像，證實99mTc(I)-HYNIC-octreotide對具體抑素受體之腫瘤有造影之潛力。

Octreotide, a cyclopeptide with eight amino acids, is a somatostatin analog with the affinity to somatostatin receptors. The aim of the study is to develop 99mTc(I)-HYNIC-octreotide as radiopharmaceutical for somatostatin receptor scintigraphy. HYNIC-octreotide is synthesizd by the method of solid-phase peptide synthesis with disulfide bonding developed by Institute of Nuclear Energy Research. HYNIC and [99mTc(CO)3(OH2)3]+ were prepared respectively according to the previous reports. Octreotide was labeled with [99mTc(CO)3(OH2)3]+ via HYNIC as a bifunctional chelator. 99mTc(I)-HYNIC-octreotide was prepared by mixing the [99mTc(CO)3(OH2)3]+ solution with HYNIC-octreotide in saline at 75℃. According to the results, the radiochemical purity for 99mTc(I)-HYNIC-octreotide was greater than 90%. The labeling technique for 99mTc(I)-HYNIC-octreotide has been successfully established in this study. The HYNIC-octreotide efficiently inhibited the binding ability of 125I-Tyr11-somatostatin with somatostatin receptor regarding to the retention of its receptor-binding affinity. In the animal model, 99mTc(I)-HYNIC-octreotide was uptaken by the pancreas tumor cells (AR42J) implanted into the SCID mice, and the result showed by showing a clear image for the tumor. These results demonstrated that 99mTc(I)-HYNIC-octreotide is potential for imaging pancreas tumors via somatostatin receptors .

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