Urinary marker for oxidative stress in kidneys in cisplatin-induced acute renal failure in rats.

BACKGROUND: Establishment of non-invasive urinary biomarkers for the prediction of acute renal failure (ARF) is important. We evaluated whether urinary oxidative stress markers reflect intrarenal oxidative stress in cisplatin (CDDP)-induced ARF, and whether these markers can be used for the prediction of future ARF. METHODS: Urinary malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured up to day 14 post-CDDP (6 mg/kg) injection in rats. MDA and 8-OHdG expressions were examined in kidneys. RESULTS: CDDP induced an increase in serum creatinine (Scr), blood urea nitrogen (BUN), and tubular damage at day 5, increased urinary MDA excretion and MDA expression in kidneys at day 1 (but returned to basal values by day 3), increased urinary excretion of 8-OHdG at day 5 till day 14 (though the number of 8-OHdG-positive tubular cells increased at day 5 and then gradually decreased). Urinary MDA levels at day 1 correlated significantly with Scr (rho = 0.721, P < 0.01) and tubular damage score (rho = 0.840, P < 0.01) at day 5. CONCLUSION: Our findings demonstrated divergent changes of urinary oxidative stress markers in CDDP-induced ARF, and suggested that urinary MDA may be a useful marker for the prediction of the development of CDDP-induced ARF.