Magnesium co-administration decreases cisplatin-induced nephrotoxicity in the multiple cisplatin administration.

PURPOSE: Pretreatment with magnesium (Mg) has been reported to attenuate cisplatin (CDDP)-induced nephrotoxicity (CIN). This attenuation involves modulation of the expression of renal transporters, resulting in reduced renal platinum accumulation after a single round of CDDP treatment. In this study, we investigated whether Mg co-administration ameliorates CIN after multiple doses of CDDP as effectively as after a single dose.

METHODS

Rats were divided into control, Mg alone, CDDP alone, and CDDP with Mg groups. Rats received CDDP (2.5mg/kg), MgSO4 (40mg/kg), or saline once per week for three weeks. Seven days after the third round of treatment, the kidneys were excised, and the expression of renal transporters and renal platinum accumulation were analyzed.

RESULTS

CDDP significantly elevated serum creatinine levels, which were significantly reduced by Mg co-administration. Renal platinum accumulation was significantly lower in the CDDP-Mg group than in the CDDP group. Expression of renal organic cation transporter 2 (rOct2) and multidrug and toxin extrusion protein 1 (rMate1), which are involved in CDDP transport, did not differ between the groups. However, the expression of copper transporter 1 (rCtr1) was significantly downregulated after Mg co-administration.

CONCLUSION

Mg co-administration significantly attenuated CIN by reducing renal platinum accumulation even after multiple rounds of treatment with CDDP as effectively as in a model of a single CDDP administration. However, the specific underlying mechanism was different between single and multiple administrations, further studies will be needed to identify what contributes to this difference and to elucidate how Mg regulates the expression of renal transporters.