Distribution and urinary excretion of aluminium injected with several organic acids into mice: relationship with chemical state in serum studied by the HPLC-ICP method.

The correlation between the in vivo tissue distribution or the urinary excretion of aluminium (Al) administered with four organic acids and the in vitro binding of Al to serum protein in the presence of the organic acids was studied: Aluminum was injected intraperitoneally into mice with an organic acid at a dose of 20 mg Al kg-1 (Al:ligand= 1:1 or 1:3). When the Al-citrate mixture was administered, hepatic and renal concentrations of Al at 3 h were low, while hepatic Al concentrations for the other three organic acids (malate, tartrate and isocitrate) were considerably higher. Compared to the sole administration of Al, urinary excretion of Al was at a high level in all organic acids. Aluminium added in vitro to control serum as an Al-citrate mixture was present only in a low-molecular-weight (LMW) fraction, while Al added with other organic acids was present in both the high-molecular-weight (HMW) and LMW fractions. Consequently, it was interpreted that Al in the LMW fractions was excreted into the urine and that a significant part of Al in the HMW fractions was transferred to the liver. The binding status of Al in serum observed in the in vitro study was also manifested in the in vivo samples obtained after the intravenous injection.