The interactions of nitric oxide with intracellular redox status and the influence of molecular hydrogen.

Nitric oxide (NO) has a wide range of effects in both animals and plants. It accumulates in cells, especially during stress responses, leading to signalling events. Many of these downstream signals rely on S-nitrosation, or nitration of proteins, but NO also interacts with a range of other cellular components, including lipids, but also other small reactive compounds. A well-known example of such a NO reaction is with the reactive oxygen species (ROS) superoxide, producing peroxynitrite (ONOO-). One characteristic of cells which is crucial to the control of cellular activity is the intracellular redox state, and this is maintained by compounds such as glutathione (GSH), but also impinged upon by ROS, reactive sulfur compounds such as hydrogen sulfide (H2S), and potentially by hydrogen gas (H2). Into this mix is NO, and here the potential influence of NO on cellular redox is discussed.