Höltke Carsten, Waldeck Jens, Kopka Klaus, Heindel Walter, Schober Otmar, Schäfers Michael, Bremer Christoph
Department of Clinical Radiology, University Hospital Muenster, Muenster, Germany.
Mol Imaging. 2009 Jan-Feb;8(1):27-34.
Biodistribution studies are essential for understanding the biologic behavior of novel fluorochrome-based molecular imaging agents. In this study, the biodistribution of a recently developed fluorescent imaging probe with high affinity to the endothelin A (ET(A)) receptor was evaluated by fluorescence reflectance imaging (FRI). CD-1 mice were injected with 2 nmol of the probe intravenously and sacrificed at various time points. Tissue samples of the heart, spleen, lung, kidneys, liver, brain, and muscle were removed and imaged by FRI. Initially, the signal intensity (SI) was highest in lung, kidney, and liver tissue, followed by the heart, whereas spleen, muscle, and brain showed the lowest SI. In the kidneys, the SI decreased rapidly. In the heart, an initial SI increase was observed, followed by SI attenuation, whereas in the lung, the SI steadily increased. Competition experiments showed a significant (p < .005) degree of specific binding in the heart, with a reduction in SI of > 50%. In conclusion, FRI allows us to perform biodistribution studies of novel fluorescent tracers. The developed imaging probe can be exploited to image ET A receptor expression ideally 30 minutes to 3 hours after injection.
生物分布研究对于理解新型荧光染料基分子成像剂的生物学行为至关重要。在本研究中，通过荧光反射成像（FRI）评估了一种最近开发的对内皮素A（ET(A)）受体具有高亲和力的荧光成像探针的生物分布。给CD-1小鼠静脉注射2 nmol探针，并在不同时间点处死。取出心脏、脾脏、肺、肾脏、肝脏、脑和肌肉的组织样本，并用FRI成像。最初，肺、肾和肝组织中的信号强度（SI）最高，其次是心脏，而脾脏、肌肉和脑的SI最低。在肾脏中，SI迅速下降。在心脏中，观察到SI最初升高，随后衰减，而在肺中，SI稳步升高。竞争实验表明，心脏中存在显著（p <.005）程度的特异性结合，SI降低> 50%。总之，FRI使我们能够进行新型荧光示踪剂的生物分布研究。所开发的成像探针可用于在注射后30分钟至3小时理想地成像ET A受体表达。
