Renal aluminum excretion

Abstract

Urinary aluminum (Al) excretion was studied in humans with normal and impaired renal function. Al was measured by atomic absorption spectrometry. In healthy volunteers (n=50), renal Al excretion was 12.2±8.5 μg/24 h.

Two patients on plasma exchange therapy with normal renal function and an inadvertent load of 870 and 388 μg Al/treatment showed a 23 and 14% positive balance until next treatment.

The renal pathway of excretion was shown to be important in 6 chronic renal failure patients on continuous peritoneal dialysis with residual renal function who eliminated in 24 h 51.4±24.0 μg Al by urine and only 27.2±18.4 μg Al across the peritoneum following a daily oral application of 342 mg Al.

Studies with the isolated perfused rat kidney confirmed the limited renal capacity to eliminate Al. Al clearance declined from 0.75 to <0.08 mL/min when the kidney was perfused with 0.04–12.4 μg Al/mL medium. Al content of the kidney increased in a dose-dependent manner from <0.5 to 4.4 μg/kidney and reached saturation at 5 μg Al/mL medium.