1H spin echo NMR was used to follow the release of reactive oxygen species (ROS) from human monocytes by monitoring erythrocyte glutathione status, which is sensitive to applied oxidative stress. This allowed the ability of the cytokine interleukin-6 (IL-6) to stimulate release of ROS from monocytes to be assessed in terms of oxidative damage to other cells, providing an estimation of its importance in vivo. It was found that incubation of monocytes with erythrocytes in the presence of IL-6 resulted in oxidation of the erythrocyte glutathione pool, indicating that oxidants are released in sufficient amounts to cause oxidative stress. High levels of IL-6 occurring in plasma of women with severe pre-eclampsia could therefore be responsible for depleted plasma antioxidants and haemolysis. The oxidation of erythrocyte glutathione was inhibited by the presence of the cyclooxygenase inhibitor indomethacin, suggesting that this may be of value in the treatment of oxidative pathologies.
- oxidative stress