Effect of basic amino acids and aminoglycosides on ³H-gentamicin uptake in cortical slices of rat and human kidney

The uptake of ³H-gentamicin was assessed in renal cortical slices of Fischer 344 male rats and four human cadaver kidneys not utilized for renal transplantation. In both species the uptake was maximal at 90 min and maintained a steady state thereafter. The characteristics of the energy-dependent component of ³H-gentamicin uptake were not altered by various basic amino acids, but competitive inhibition was induced by other aminoglycosides in a dose-dependent fashion. Thus aminoglycosides appear to share a transport process that is distinct from those of organic bases or other cationic substances. In addition, under the experimental conditions employed, the basolateral membrane of the tubular cell is capable of energy-dependent uptake of gentamicin. The role of this route of cellular uptake of aminoglycoside in clinical nephrotoxicity is speculative.