Nitric oxide (NO), a short-lived gaseous molecule, plays a key role in many physiological and developmental processes.As a lipophilic molecule that can cross all the barriers of biological membranes, NO is able to react with various intracellular/extracellular targets and form a series of reactive nitrogen species (RNS), such as NO radicals (NO-), nitrosonium ions (NO*), peroxynitrite (ONOO-), S-nitrosothiols (SNOs), higher oxides of nitrogen (NOx) and dinitrosyl-iron complexes among others.As a signal mediator, RNS executes its physiological effects mainly through protein S-nitrosylation: the addition of an NO moiety to the cysteine thiol of a protein forms an S-nitrosothiol (SNO).Many studies have established that the dynamic processes of S-nitrosylation and denitrosylation are predominantly modulated by the intracellular level of S-nitrosoglutathione (GSNO), a major bioactive NO species in organisms.