Kojima S, Jay M
Eur J Nucl Med. 1986;12(8):385-9. doi: 10.1007/BF00252195.
We investigated the in vitro binding of 125I-lectins to Ehrlich ascites tumor (EAT) cells and in vivo uptake of 125I-lectins in Ehrlich solid tumor (EST) bearing mice. In in vitro binding assays, phaseolus vulgaris agglutinin (PHA), pisum sativum agglutinin(PSA), and concanavalia agglutinin(Con A) showed a high affinity for EAT cells. The in vivo biodistribution of 125I-lectins showed 125I-I-PSA to be significantly taken up into EST tissues 24 h postinjection. After IV injection of 125I-PSA, uptake of the radioactivity into the tumor tissues reached a maximum at 6 h, and thereafter decreased. Rapid clearance of the radioactivity from blood and its excretion into kidney soon after injection of 125I-PSA were observed. When compared with the biodistribution of 67Ga-citrate in EST bearing mice 24 h postinjection, tumor to liver (T/B), tumor to muscle (T/M), and tumor to blood (T/B) ratios were superior for 125I-PSA. At 6 h postinjection, the T/B-ratio of 125I-PSA was 2.5, and this value may be sufficient to enable discernible diagnostic images. Our results suggest that PSA might be a useful tumor imaging radiopharmaceutical.
我们研究了¹²⁵I-凝集素与艾氏腹水瘤（EAT）细胞的体外结合以及¹²⁵I-凝集素在荷艾氏实体瘤（EST）小鼠体内的摄取情况。在体外结合试验中，菜豆凝集素（PHA）、豌豆凝集素（PSA）和刀豆球蛋白A（Con A）对EAT细胞显示出高亲和力。¹²⁵I-凝集素的体内生物分布显示，¹²⁵I-PSA在注射后24小时显著被EST组织摄取。静脉注射¹²⁵I-PSA后，肿瘤组织对放射性的摄取在6小时达到最大值，此后下降。观察到注射¹²⁵I-PSA后放射性从血液中快速清除并很快排泄到肾脏。与注射后24小时荷EST小鼠体内⁶⁷Ga-柠檬酸盐的生物分布相比，¹²⁵I-PSA的肿瘤与肝脏（T/B）、肿瘤与肌肉（T/M）以及肿瘤与血液（T/B）比值更优。注射后6小时，¹²⁵I-PSA的T/B比值为2.5，该值可能足以获得可辨别的诊断图像。我们的结果表明，PSA可能是一种有用的肿瘤显像放射性药物。
