Elizondo G, Fretz C J, Stark D D, Rocklage S M, Quay S C, Worah D, Tsang Y M, Chen M C, Ferrucci J T
Department of Radiology, Massachusetts General Hospital, Boston.
Radiology. 1991 Jan;178(1):73-8. doi: 10.1148/radiology.178.1.1898538.
Manganese(II)-N,N'-dipyridoxylethylenediamine-N,N'-diacetate-5,5'-bis (phosphate) (MnDPDP) is a paramagnetic complex designed for use as a hepatobiliary agent. The T1 relaxivity of MnDPDP (2.8 [mmol/L]-1.sec-1 in aqueous solution) was similar to that of gadolinium diethylenetriaminepentaacetic acid (DTPA) (4.5 [mmol/L]-1.sec-1) and gadolinium tetraazocyclodecanetetraacetic acid (DOTA) (3.8 [mmol/L]-1.sec-1). However, in liver tissue the T1 relaxivity of MnDPDP (21.7 [mmol/L]-1.sec-1) was threefold higher than that reported for Gd-DOTA (6.7 [mmol/L]-1.sec-1). Maximum liver T1 relaxation enhancement occurred 30 minutes after injection of MnDPDP, at which time 54MnDPDP biodistribution studies indicated that 13% of total body activity was in the liver. Enhanced (MnDPDP, 50 mumol/kg) MR images showed a fivefold increase in tumor-liver contrast-to-noise ratio over baseline unenhanced images. Results of the authors' acute and subchronic toxicity studies suggest that MnDPDP will be safe at the doses necessary for clinical imaging; at 10 mumol/kg, the safety factor (LD50/effective dose) for MnDPDP is 540, significantly greater than the safety factor of Gd-DTPA (ie, 60-100).
锰（II）-N，N'-二吡啶氧基乙二胺-N，N'-二乙酸-5，5'-双（磷酸酯）（MnDPDP）是一种设计用作肝胆显像剂的顺磁性复合物。MnDPDP在水溶液中的纵向弛豫率（2.8[mmol/L]-1·秒-1）与钆二乙三胺五乙酸（DTPA）（4.5[mmol/L]-1·秒-1）和钆四氮杂环十二烷四乙酸（DOTA）（3.8[mmol/L]-1·秒-1）相似。然而，在肝组织中，MnDPDP的纵向弛豫率（21.7[mmol/L]-1·秒-1）比报道的Gd-DOTA（6.7[mmol/L]-1·秒-1）高三倍。注射MnDPDP后30分钟出现肝脏纵向弛豫增强最大值，此时54MnDPDP生物分布研究表明全身活性的13%在肝脏中。增强后的（MnDPDP，50μmol/kg）磁共振图像显示肿瘤-肝脏对比噪声比相对于基线未增强图像增加了五倍。作者的急性和亚慢性毒性研究结果表明，MnDPDP在临床成像所需剂量下将是安全的；在10μmol/kg时，MnDPDP的安全系数（半数致死量/有效剂量）为540，显著高于Gd-DTPA的安全系数（即60-100）。
