Jackson G E, Wynchank S, Woudenberg M
Department of Chemistry, University of Cape Town, Rondebosch, South Africa.
Magn Reson Med. 1990 Oct;16(1):57-66. doi: 10.1002/mrm.1910160107.
A computer model of blood plasma which has allowed the effect of Gd(III) contrast agents to be simulated has been developed. Initial binding of Gd(III) is to transferrin. At high concentration the metal ion binds to citrate and salicylate. At a concentrate of 10(-3) M, GdCl3 is predicted to effect a redistribution of the in vivo Zn(II), Ca(II), and Fe(II) complexes present in blood plasma. There is little effect on the Cu(II) distribution. At a concentration below 10(-5) M EDTA and DTPA have little effect on the free Gd(III) metal ion concentration. Above this concentration though, the metal ion is bound almost exclusively to the EDTA or DTPA. An attempt is made to relate the toxicity of GdCl3, [Gd(EDTA)]-, and [Gd(DTPA)]2- to the thermodynamic stability of these complexes. The effect of substitution kinetics is also discussed.
已开发出一种血浆计算机模型，可用于模拟钆（III）造影剂的作用。钆（III）的初始结合对象是转铁蛋白。在高浓度下，金属离子会与柠檬酸盐和水杨酸盐结合。在浓度为10⁻³ M时，预计氯化钆会影响血浆中体内锌（II）、钙（II）和铁（II）络合物的重新分布。对铜（II）的分布影响很小。在浓度低于10⁻⁵ M时，乙二胺四乙酸（EDTA）和二乙烯三胺五乙酸（DTPA）对游离钆（III）金属离子浓度影响很小。然而，高于此浓度时，金属离子几乎完全与EDTA或DTPA结合。人们试图将氯化钆、[钆（乙二胺四乙酸）]⁻和[钆（二乙烯三胺五乙酸）]²⁻的毒性与这些络合物的热力学稳定性联系起来。还讨论了取代动力学的影响。
