Effects of nifedipine on cisplatinum-induced nephrotoxicity in rats

The effects of calcium channel blockade with nifedipine (N) on cis-diammine dichloroplatinum II (CDDP)-induced nephrotoxicity were tested in male Sprague-Dawley rats. Renal function was evaluated before and five days after CDDP administration (5 mg/kg). The rats were treated with various doses of N (0.1; 0.3; 0.6 mg/kg/day) 2 days before CDDP administration and throughout the study. The severity of CDDP-induced acute renal failure was markedly modified in N-treated animals according to the daily dosage of N. At 0.3 and 0.6 mg/kg BW/day, N enhanced CDDP nephrotoxicity. Serum creatinine was 637 +/- 45 and 611 +/- 71 mumoles/liter, respectively, 5 days after CDDP administration (vs. 313 +/- 24 mumoles in animals treated with CDDP alone; p less than 0.05). In these animals the plasma potassium level was significantly elevated at day 7 when compared with CDDP-treated and control rats. In contrast, at the dose of 0.1 mg/kg BW/day N attenuated CDDP nephrotoxicity with a serum creatinine of 214 +/- 35 mumoles at the end of the study. The pathologic changes were also more severe in the groups receiving 0.3 and 0.6 mg/kg of nifedipine. We postulate that at the higher doses (0.3 and 0.6 mg/kg) the systemic hemodynamic effects of nifedipine may override the potentially beneficial intrarenal effect which may account for the favorable results recorded with a dosage of 0.1 mg/kg.