van Zijl P C, Place D A, Cohen J S, Faustino P J, Lyon R C, Patronas N J
Biophysical Pharmacology Section, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
Acta Radiol Suppl. 1990;374:75-9.
The criteria for tumor-specific MRI contrast agents are considered. The metalloporphyrins have been shown to be potential tumor-specific contrast agents due to their selective retention by cancer cells. The Mn(III) water-soluble porphyrin complexes are preferred on the basis of relaxivity and stability. Protein binding in human plasma enhances the relaxivity of Mn(III)-tetraphenylsulfonato-porphyrin (MnTTPS). In preliminary work this agent was shown to enhance MRI contrast at 0.5 T in subcutaneous human colon carcinomas grown in nude mice. Here we report further evidence of enhanced contrast in the same system, and extend this work to human breast tumors in nude mice using a 2 T animal imager. Questions of metalloporphyrin stability, toxicity and dose-contrast relationship are discussed.
对肿瘤特异性磁共振成像（MRI）造影剂的标准进行了考量。金属卟啉已被证明是潜在的肿瘤特异性造影剂，因为癌细胞能选择性地摄取它们。基于弛豫率和稳定性，锰（III）水溶性卟啉配合物是更优的选择。人血浆中的蛋白质结合增强了锰（III）-四苯基磺酸根卟啉（MnTTPS）的弛豫率。在初步研究中，该造影剂在0.5特斯拉磁场下，可增强裸鼠皮下人结肠癌的MRI对比度。在此，我们报告在同一系统中对比度增强的进一步证据，并使用2特斯拉动物成像仪将此研究扩展至裸鼠体内的人乳腺肿瘤。还讨论了金属卟啉的稳定性、毒性及剂量-对比度关系等问题。
