Age-related differences in nephrotoxicity of cadmium

Nephrotoxic effects can be quantified by measurement of renal excretion of p-amino-hippurate (PAH). Intraperitoneal administration of cadmium in increasing single doses to adult rats is followed by a biphasic effect on renal PAH excretion. Administration of low doses (250 or 500 micrograms/100 g b.wt. CdCl2) results in a significant increase whereas a single dose of 750 micrograms/100 g b.wt. CdCl2 is followed by a distinct diminution of renal PAH excretion. Repeated administrations of 500 micrograms/100 g b.wt. CdCl2 for 2 or 3 consecutive days result in a marked reduction of PAH excretion which is reversible 5 or 6 d following administration. In juvenile rats cadmium does not produce any statistically significant alteration in renal PAH excretion, likely caused by the immaturity of renal tubular transport processes.