Nitrite: A physiological store of nitric oxide and modulator of mitochondrial function

Nitrite, long considered a biologically inert metabolite of nitric oxide (NO) oxidation, is now accepted as a physiological storage pool of NO that can be reduced to bioactive NO in hypoxic conditions to mediate a spectrum of physiological responses in blood and tissue. This graphical review will provide a broad overview of the role of nitrite in physiology, focusing on its formation and reduction to NO as well as its regulation of the mitochondrion—an emerging subcellular target for its biological actions in tissues.

► Nitrite is a stable physiological reservoir of nitric oxide. ► Nitrite reductase enzymes reduce nitrite to NO to mediate physiological responses. ► The mitochondrion is an important physiological target for nitrite.