Pancreatic receptors: initial feasibility studies with a targeted contrast agent for MR imaging.
Pancreatic receptors: initial feasibility studies with a targeted contrast agent for MR imaging.
复制标题
胰腺受体：针对 MR 成像的靶向造影剂的初步可行性研究。
DOI：
10.1148/radiology.193.2.7972773
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发表时间：
1994
期刊：
影响因子：
19.7
通讯作者：
Brady,TJ
中科院分区：
文献类型：
--
作者：
Reimer,P;Weissleder,R;Shen,T;Knoefel,WT;Brady,TJ
材料与方法：采用非共价键法将胆囊收缩素（CCK）标记于氧化铁单晶（MION）上。结合物的受体特异性用竞争性结合研究确定。药理学测定包括血液半衰期、生物分布、时间反应、剂量反应和有限毒性。MION-20-CCK的细胞特异性结合可被CCK拮抗剂饱和和抑制。MION-20-CCK的血液半衰期为20 min，比未标记的MION短。生物分布研究显示，给予MION-20-CCK后，胰腺组织的弛豫时间从42.7 msec +/- 2.0降至33.8 msec +/- 1.4（P <或= 0.05），但肿瘤中的弛豫时间无统计学显著性降低。MION-20-CCK在胰腺中的半衰期为3周;在检测水平上没有显示毒性迹象。需要进行额外的研究来完善结合策略、优化制备并扩大合成以用于其他物种的成像。
PURPOSETo evaluate cholecystokinin (CCK) as a target-specific vector for magnetic resonance (MR) receptor imaging of rat pancreas.MATERIALS AND METHODSMonocrystalline iron oxide (MION) was labeled with CCK by noncovalent attachment. Receptor specificity of the conjugate was determined with competitive binding studies. Pharmacologic determinations were blood half-lives, biodistribution, time responses, dose responses, and limited toxicity.RESULTSSpecific cell binding of MION-20-CCK was saturable and inhibitable by a CCK antagonist. Blood half-life of MION-20-CCK was 20 minutes, which was shorter than that of unlabeled MION. Biodistribution studies showed a statistically significant decrease in relaxation times in pancreatic tissues from 42.7 msec +/- 2.0 to 33.8 msec +/- 1.4 (P < or = .05) but not in tumor after administration of MION-20-CCK. The half-life of MION-20-CCK in the pancreas was 3 weeks; no signs of toxicity were shown at the level tested.CONCLUSIONTarget-specific MR imaging of pancreatic receptors is feasible. Additional studies are necessary to perfect binding strategies, optimize preparations, and scale up synthesis for imaging in other species.