Computer Simulation of Speciation of Trivalent Aluminum, Gadolinium and Yttrium Ions in Human Blood Plasma

Abstract

The speciation of Al3+, Gd3+ and Y3+ ions in human plasma has been studied by computer simulation using the program HySS2009. A literature computer model of blood plasma was updated and comprised 9 metals, 43 ligands and over 6100 complexes. To this model critically evaluated data of Al3+, Gd3+ and Y3+ constants with blood plasma ligands have been added. Low molecular mass (LMM) speciation of Al3+ ion strongly depends upon the chosen equilibrium model of the metal - phosphate and metal - citrate systems. The obtained computer simulation of LMM speciation data of Al3+ ion were: AlPO(4)Cit (40.7%), AlPO(4)CitOH (22.9%), AlCitOH (19.2%) and AlPO4(OH) (12.7%) (% of total LMM Al species pool); for Gd3+ ion: GdAspCit (30%) and GdCit(OH)(2) (20%) (% of total [Gd]) and for Y3+ ion: YCit (48%), Y(CO3)(2) (32%) and Y(CO3) (11%) (% of total [Y]). Citrate appears as the important binding and mobilizing ligand for all examined ions, while the dominating species are the ternary ones.