Release of renal dipeptidase from rabbit renal proximal tubules and its inhibition by gentamicin

Effects of several drugs on rabbit renal proximal tubules were examined for the applicability of renal dipeptidase (RDPase, EC 3. 4. 13. 11) release a s a model system to study nephrotoxicity. The proximal tubule prepared by t he method of Taub (1990) released RDPase spontaneously in the control exper iment which was confirmed by Western blotting. RDPase was also released fro m cisplatin, lipopolysaccharide (LPS), and indomethacin-treated tubules. Ge ntamicin inhibited RDPase release in a concentration-dependent manner. This RDPase release system may not be a general model to screen nephrotoxicity but could be a useful source of RDPase purification in a simple and inexpen sive way.