Renal clearance of aluminium: studies in the isolated perfused rat kidney

The model of isolated rat kidney was used to study the renal handling of aluminium (Al). The kidney function remained unchanged at perfusate concentrations of Al in a range of 0.04-12.4 micrograms/ml during a perfusion period of 60 min. The clearance values of Al decreased with increasing concentrations of Al in the perfusate. The fractional Al clearance was reduced from 70% at the lowest Al concentration in the perfusate to 8.2% at the highest Al concentration. The Al content of the kidneys increased dose-dependently and reached a maximum value of 4 micrograms Al per kidney at a perfusate concentration of 5 micrograms Al/ml. Protein-binding studies with Al confirmed the suggestion that renal elimination of Al is dependent on the degree of Al binding. It is proposed that at low Al load in the plasma, the kidney possesses the capability to eliminate Al in an effective manner.