87th Annual Meeting of the German Physiological Society in Cologne date:2-5 March 2008
The cellular redox state is influenced by many extra- and intracellular factors, and can in turn take part in signaling processes, e.g. via sulfhydryl modulation. One major source of redox state disturbance is the mitochondrial generation of reactive oxygen species (ROS). So far redox-sensitive dyes have been used to probe the cellular ROS production, but their oxidation is irreversible, they are cytotoxic and autooxidize easily. By transfecting cultured hippocampal neurons with the innovative redox sensitive roGFP1 we succeeded in monitoring dynamic changes in cytosolic ROS-levels. Cytosolic roGFP was reversibly oxidized by H2O2, •O2- produced by xanthine/xanthine oxidase and •OH-radicals generated by FeSO4 plus H2O2. CN- immediately increased ROS production, while N2-mediated anoxia and DPI had the opposite effect. Changes in NADH and FAD levels in response to various mitochondrial blockers or direct oxidation by H2O2 could be recorded simultaneously by measuring the autofluorescence in acute hippocampal slices.