The role of glutathione in the transport and catabolism of nitric oxide

Nitric oxide acts as a neuronal and vascular messenger implying diffusion through intracellular environments containing 5-10 mM glutathione. Nitric oxide reacts with glutathione under aerobic conditions generating S-nitrosoglutathione (GSNO). GSNO reacts with glutathione (k= 8.3 X 10(-3) M-1 X s-1) to generate nitrous oxide and glutathione disulfide (GSSG). Anaerobically, glutathione reacts with nitric oxide generating nitrous oxide and GSSG (k= 4.8 X 10(-4) s-1 at 5 mM GSH). In both aerobic and anaerobic situations the nitroxyl anion may be an intermediate in the synthesis of nitrous oxide and, under aerobic conditions, nitroxyl anion may generate peroxynitrite. We present a hypothesis for the intracellular interaction between nitric oxide and glutathione.