In situ electrochemical monitoring of reactive oxygen and nitrogen species released by single MG63 osteosarcoma cell submitted to a mechanical stress.

The oxidative stress responses of single MG63 osteosarcoma cells submitted to a brief mechanical stress have been investigated by amperometry at platinized carbon fiber electrodes for monitoring and characterizing the nature and the amounts of the various reactive oxygen (ROS) and reactive nitrogen species (RNS) released. It was thus shown that, on average, a single MG63 cell released prominent amounts of reactive nitrogen species (17 fmol NO(*), 6 fmol ONOO(-), and 5 fmol NO(2)(-)) together with a comparatively small quantity of H(2)O(2) (2 fmol). These species resulted from the primary production of 13 fmol for O(2)(*-) and 28 fmol for NO(*) per single cell as reconstructed from the stoichiometries of the ROS and RNS releases. The high NO(*)/H(2)O(2) and NO(*)/O(2)(*-) ratios thus found are perfectly consistent with previous claims that the malignant bone formation ability of the osteosarcoma cells is related to a specific high production of NO* associated to a small one of O(2)(*-).