Mesna inactivates platinum agents in vitro

Background: Platinum agents are frequently combined with ifosfamide. Mesna, originally coadministered to protect fi om ifosfamide side effects, might also react with the platinum agents in these combinations, Methods: Maligna nt glioma cells were incubated with cisplatin, carboplatin and mesna. Cell numbers were measured by counting and by MTT-tests. Results: In cell free s olution mesna turned MTT to its blue farmazan product. Mesna's effect on ce lls were cell-line specific: It penetrated U87 cells without effect on grow th, reduced cell numbers in C6 and T98G cells and did not alter U251 cells. The concentration of cisplatin killing 50% of the cells were 7x10(-7) in C 6, 9.7x10(-6) in T98G, 1.2x10(-5) in U251 and 2.4x10(-4) in U87 cells. For the same effect, carboplatin required 3-10 times higher concentrations. Mes na protected all cell lines from the cytotoxicity of the platinum agents. C onclusion: Clinical studies should specify in detail, infusion schedules of mesna and platinum agents.