Erythropoietin reduces cumulative nephrotoxicity from cisplatin and enhances renal tubular cell proliferation

Cisplatin, a heavy metal complex, is one of the most active drugs used in the treatment of several human malignancies. However, high-dose therapy with cisplatin is limited by its cumulative nephrotoxicity. The main objectives of this study were to determine the role of recombinant human erythropoietin (Epoetin alfa) in the prevention of nephrotoxicity induced experimentally in Wistar rats by long-term administration of cisplatin (2 mg/kg/b.w./week) over eight weeks, and an evaluation of its effect on renal tubular cell proliferation. The animals were randomly assigned into three groups, each including 25 rats. Group 1 (CP) received only cisplatin (2 mg/kg/b.w./week), group 2 (CP+EPO) received cisplatin (2 mg/kg/b.w./week) and epoetin alfa (150 IE/kg/b.w./three times a week), and group 3 (control group) received only saline. During the study, the following tests for the assessment of the renal function and renal damages were performed: determination of concentration of serum creatinine and BUN and determination of total protein quantity in 24-hour urine samples. At the end of the study, the abdomen was opened and both kidneys of the rats were removed and sent for histological and morphometric analysis. Ki-67 was used as a tool to determine a proliferative index. The results obtained have shown that epoetin alfa significantly reduced the functional renal failures and renal damages, and increased toleration of high doses of cisplatin. At the same time, our results with regard to tubular proliferative index have confirmed that one of the possible mechanisms by which erythropoietin accomplishes its renoprotective effect is stimulation of tubular cell proliferation and regeneration.