Renal toxicity studies of protein-bound platinum(cis).

Incubation of dialyzed rat serum with cisplatin at a concentration of 908 ppm results in binding of platinum to the proteins and electrophoretic evidence of protein alterations. Intravenous administration of protein-bound platinum(cis), containing the same platinum content as an 8.5-mg/kg dose of cisplatin, fails to produce elevated serum BUN and creatinine levels as do equivalent doses of 'free' cisplatin in 0.9% saline. Light microscopy of the right side kidneys of rats receiving protein-bound platinum(cis) revealed no obvious pathology while the kidneys of rats receiving 'free' cisplatin showed consistent pathological alterations including hydropic degeneration and pyknotic nuclei. These observations suggest that a protein-bound form of platinum will be unlikely to contribute to the renal toxicity observed during cisplatin chemotherapy.