INVIVO APPLICATION OF [IN-111-DTPA-D-PHE1]-OCTREOTIDE FOR DETECTION OF SOMATOSTATIN RECEPTOR-POSITIVE TUMORS IN RATS
INVIVO APPLICATION OF [IN-111-DTPA-D-PHE1]-OCTREOTIDE FOR DETECTION OF SOMATOSTATIN RECEPTOR-POSITIVE TUMORS IN RATS
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DOI：
10.1016/0024-3205(91)90053-e
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发表时间：
1991-01-01
期刊：
影响因子：
6.1
通讯作者：
LAMBERTS, SWJ
中科院分区：
文献类型：
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作者：
BAKKER, WH;KRENNING, EP;LAMBERTS, SWJ
放射性碘标记的生长抑素类似物是体内和体外检测生长抑素受体的有用配体。[In-111-DTPA-D-Phe1]-octrebon是一种生长抑素类似物，用不同的放射性核素标记，在体外也能与生长抑素受体特异性结合。在这项研究中，我们研究了它在大鼠生长抑素受体阳性肿瘤可视化中的应用。静脉注射后，研究放射性药物在正常大鼠和生长抑素受体阳性的大鼠胰腺癌CA 20948大鼠体内的分布。注射后，放射性药物被迅速清除(最大血液放射性在4分钟内下降了50%)，主要是通过肾脏。排出的放射性主要以完整的放射性药物形式存在。体外放射自显影研究表明，放射性在含有生长抑素受体的组织(脑下垂体前叶)发生了特异性的积聚。然而，与肾上腺和垂体相反，示踪剂在肾脏中的蓄积不是由生长抑素受体介导的。注射后迅速测量生长抑素受体阳性肿瘤的放射性增加，并通过伽马相机闪烁成像清楚地显示肿瘤。在预先给予1 mg奥曲肽的大鼠中，[In-111-DTPA-D-Phe1]-奥曲肽在肿瘤中的蓄积被阻止。由于其较长的有效半衰期，[In-111-DTPA-D-Phe1]-奥曲肽是一种放射性核素偶联的生长抑素类似物，可用于24小时后有效地显示携带生长抑素受体的肿瘤，当干扰本底放射性通过肾清除最小化时。这比以前使用的[I-123-Tyr3]-octrebon更有优势，后者的有效半衰期较短，并且由于其肝胆清除性而显示出高度的腹部干扰。因此，[In-111-DTPA-D-Phe1]-奥曲肽似乎是一种更好的生长抑素受体肿瘤核素显像的替代方案。
Radioiodinated somatostatin analogues are useful ligands for the in vitro and in vivo detection of somatostatin receptors. [In-111-DTPA-D-Phe1]-octreotide, a somatostatin analogue labeled with a different radionuclide, also binds specifically to somatostatin receptors in vitro. In this study we investigated its in vivo application in the visualization of somatostatin receptor-positive tumors in rats. The distribution of the radiopharmaceutical was investigated after intravenous injection in normal rats and in rats bearing the somatostatin receptor-positive rat pancreatic carcinoma CA 20948. After injection the radiopharmaceutical was rapidly cleared (50 % decrease in maximal blood radioactivity in 4 min), predominantly by the kidneys. Excreted radioactivity was mainly in the form of the intact radiopharmaceutical. Ex vivo autoradiographic studies showed that specific accumulation of radioactivity occurred in somatostatin receptor-containing tissue (anterior pituitary gland). However, in contrast to the adrenals and pituitary, the tracer accumulation in the kidneys was not mediated by somatostatin receptors. Increasing radioactivity over the somatostatin receptor-positive tumors was measured rapidly after injection and the tumors were clearly visualized by gamma camera scintigraphy. In rats pretreated with 1 mg octreotide accumulation of [In-111-DTPA-D-Phe1]-octreotide in the tumors was prevented. Because of its relatively long effective half-life, [In-111-DTPA-D-Phe1]-octreotide is a radionuclide-coupled somatostatin analogue which can be used to visualize somatostatin receptor-bearing tumors efficiently after 24 hr, when interfering background radioactivity is minimized by renal clearance. This is an advantage over the previously used [I-123-Tyr3]-octreotide which has a shorter effective half-life and shows high abdominal interference due to its hepato-biliary clearance. Therefore, [In-111-DTPA-D-Phe1]-octreotide seems a better alternative for scintigraphic imaging of somatostatin receptor-bearing tumors.