Burnett K R, Goldstein E J, Wolf G L, Sen S, Mamourian A C
Magn Reson Imaging. 1984;2(4):307-14. doi: 10.1016/0730-725x(84)90197-8.
Mn+2 (as MnCl2) was administered to rabbits intravenously and orally (a route of administration which based upon our previous experiments in rats promises to give selective hepatobiliary enhancement with less systemic toxicity). Nuclear magnetic relaxation dispersion or T1 (NMRD) was performed on selected tissues (heart, liver, kidney, serum, and bile) in both animal groups to examine possible qualitative and semiquantitative differences in T1 relaxation at equivalent sacrifice times. One animal was given an oral dose of MnCl2 (620 micromoles/kg) and imaged sequentially (T1 weighted sequence, .12T) for 30 minutes. The NMRD curves for organ tissues show an increase in relaxation efficacy in the 10-20MHz range characteristic of Mn-macromolecular complexes and are similar irrespective of the route of administration. The lack of increased relaxation enhancement for bile in this frequency range reflects cleavage of this complex upon excretion. Decreased overall relaxation in the liver is observed when oral Mn+2 is compared to IV Mn+2 due to the small fraction of administered dose that is absorbed. However, the images document a significant increase in the intensity of liver signal after the oral dose. We suspect this dose may ultimately be adjusted downward to give selective hepatobiliary effects.
将二价锰（以氯化锰形式）通过静脉注射和口服的方式给予兔子（基于我们之前在大鼠身上进行的实验，这种给药途径有望实现选择性肝胆增强且全身毒性较小）。对两组动物的选定组织（心脏、肝脏、肾脏、血清和胆汁）进行核磁共振弛豫分散或T1（NMRD）检测，以检查在相同处死时间下T1弛豫可能存在的定性和半定量差异。给一只动物口服一剂氯化锰（620微摩尔/千克），并连续成像（T1加权序列，0.12T）30分钟。器官组织的NMRD曲线显示在10 - 20MHz范围内弛豫效果增加，这是锰大分子复合物的特征，且无论给药途径如何都相似。在该频率范围内胆汁的弛豫增强没有增加，这反映了该复合物在排泄时的裂解。与静脉注射二价锰相比，口服二价锰时肝脏的整体弛豫降低，这是因为吸收的给药剂量比例较小。然而，图像显示口服给药后肝脏信号强度显著增加。我们怀疑该剂量最终可能会下调以产生选择性肝胆效应。
