Increase in the ATP signal after treatment with cisplatin in two different cell lines studied by 31P NMR spectroscopy.

We have compared the 31P nuclear magnetic resonance (NMR) spectra of two different cisplatin resistant cell lines, one derived from human ovarian carcinoma and the other from rat lymphoma, and their respective cisplatin sensitive parental cell lines. Comparisons were made between the baseline spectra and after perfusion of the cells with 20-50 microM cisplatin for 16-20 hours. While no obvious differences were found between baseline spectra of sensitive and resistant cells, during cisplatin perfusion the sensitive cells had an increase in their ATP signals. The resistant cells also exhibited increases in their ATP signals during cisplatin perfusion but to a lesser extent than the sensitive cells. Although the significance of these ATP elevations towards the cellular pharmacology of cisplatin are not presently known, our studies demonstrate that 31P NMR spectroscopy may be useful for elucidating differences in phosphate metabolism in cells expressing the cisplatin resistant phenotype.