Computer Simulation for Effect of Tb^(3+) on Ca^(2+)Speciation in Human Plasma

摘要

Effect of Tb 3+ on Ca 2+ speciation in human plasma was studied by means of the computer program of MINTEQA2. When Tb 3+ ions are not added into the system, Ca 2+ ions mostly distribute in free Ca 2+ (74.7%) and the surplus distributes in Ca 2+ complexes, such as [CaHCO 3] +(7.9%), [Ca(Lac)] +(6.4%), CaHPO 4 (1 3%), [CaHistidinateThreoninateH 3] 3+ (2.4%), [CaCitrateHistidinateH 2] (2.3%) and CaCO 3(1.1%). Tb 3+ can compete with Ca 2+ for inorganic as well as biological ligands. An increase of concentration of Tb 3+ in the system results in an increase of content of free Ca 2+ and a decrease of contents of Ca 2+ complexes.