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背景应用放射性核素标记小分子肽类配体进行肿瘤受体显像,针对肿瘤组织所表达的高密度αvβ3受体,发展放射性标记的含RGD序列的高选择性αvβ3受体拮抗剂,是目前肿瘤受体显像研究的热点。目的以实验动物为基础,探讨放射性核素标记小分子环形多肽RGD-4CY实现肿瘤αvβ3受体显像的可行性。设计完全随机的实验对照。地点和对象实验在解放军第三军医大学西南医院核医学中心完成研究对象为25只正常小鼠和15只荷人QBC939胆管癌裸鼠,由解放军第三军医大学实验动物中心提供,4～6周龄,体质量15～20g。干预采用Iodogen法标记、SEP-PAKC18柱分离纯化制备125I-RGD-4CY。取25只正常小鼠与15只荷人QBC939胆管癌裸鼠,经尾静脉注射125I-RGD-4CY0.1mL(370kBq),分别于注射后10,30,60,120和240min各取5只与3只处死,测定体内放射性的生物分布。取3只荷瘤裸鼠各注射0.1mL(3.7MBq)125I-RGD-4CY,1h后处死并行全身放射自显影。主要观察指标125I-RGD-4CY的放射化学纯度;125I-RGD-4CY的体内分布及动力学特点,肿瘤(T)与非肿瘤组织(NT)放射性比值;自显影图像中瘤体及正常组织的放射性分布。结果125I-RGD-4CY的放射化学纯度为99%。正常小鼠血液放射性清除和肝脏放射性下降迅速,肠道无明显增加,主要通过肾脏排泄,肌肉和肺的放射性120mi
Background Radionuclide-labeled small molecule peptide ligands for tumor receptor imaging have been developed. For the development of high-density αvβ3 receptors expressed in tumor tissues, the development of radiolabeled highly selective αvβ3 receptor antagonists with RGD sequences is currently Tumor receptor imaging research hot spots. Objective To investigate the feasibility of using radionuclide labeled small molecule circular peptide RGD-4CY to achieve tumor αvβ3 receptor imaging based on experimental animals. Design completely randomized experimental control. Location and Subjects Experiments were performed at the Nuclear Medicine Center of Southwest Hospital of the Third Military Medical University of PLA. Twenty-five normal mice and 15 QBC939 cholangiocarcinoma nude mice were performed. The experimental animals were provided by the Experimental Animal Center of the Third Military Medical University of PLA. After 4-6 weeks Age, body mass 15 ~ 20g. The Iodogen method was used for the intervention and the 125I-RGD-4CY was isolated and purified by SEP-PAKC18 column. Twenty-five normal mice and 15 QBC939 human cholangiocarcinoma nude mice were injected with 125I-RGD-4CY0.1mL (370kBq) through the tail vein. Five and three mice were injected at 10, 30, 60, 120 and 240min after injection Sacrificed, measured in vivo biological biodistribution. Three nude mice bearing each injection of 0.1mL (3.7MBq) 125I-RGD-4CY, 1h after death were performed concurrent whole body autoradiography. The radiochemical purity of 125I-RGD-4CY, the distribution and kinetic characteristics of 125I-RGD-4CY, the radioactivity ratio of tumor to non-tumor tissue (NT) Radioactive distribution. Results The radiochemical purity of 125I-RGD-4CY was 99%. Normal mice blood radioactivity clearance and rapid decline in liver radioactivity, no significant increase in the intestine, mainly through the kidneys excretion, muscle and lung radioactive 120mi