[Comparative studies on the action of aminoglycosides and cephalosporins on the proximal tubule of the human kidney (author's transl)].

Tubulo-toxic effects of drugs can be recognised by the elimination of portions of brush border membrane in the urine. An integral constituent of the brush border membrane is an alanine aminopeptidas (AAP). It is measurable in the urine enzymatically and immunologically with great reliability. The AAP activity was determined in the 24-hour urine of test subjects. Fifteen subjects received 3 mg/kg gentamicin, sisomicin or tobramycin on 3 consecutive days and 10 subjects were given amikacin (15 mg/kg). In addition, 15 subjects received cephacetrile (8.0 g), cephazolin (6.0 g) or cephalothin (8.0 g) on 3 consecutive days. It was shown that all aminoglycosides have a cumulative effect on the brush border membrane, amikacin is the strongest and tobramycin the weakest. The cephalosporins cephalothin and cephazolin were indifferent to the tubule membranes and had no effect on the excretion of AAP. There were responders and non-responders to cephacetrile. The application of cephalothin and cephazolin immediately before the administration of gentamicin prevents the membrane effect of gentamicin.