Contents

Search

nitric oxide (NO, endothelium derived relaxation factor {EDRF})

Function: - a colorless gas & a free radical - nitric oxide reacts rapidly with oxygen to form nitrogen oxides, which ultimately convert to nitrite (NO2-) & nitrate (NO3-) NO + O2 -> NO2 + N2O3 + N2O2 -> NO2- + NO3- - nitric oxide is a gaseous mediator of cell to cell communication & a potent vasodilator - insufficient NO may contribute to hypertension - nitric oxide activates soluble guanylate cyclase - it mediates penile erection. - in the immune system, macrophages use nitric oxide as a cytotoxic agent. - free nitric oxide in the circulation is rapidly reduced by Fe+2 of hemoglobin - nitric oxide covalently binds to Cyst of proteins resulting in S-nitrosylated derivatives [2,3] - S-nitrosylation is reversible - targets of S-nitrosylation include: - Na+ pump - Na+ K+ ATPase - alpha tubulin - NMDA receptor - GAPDH* * S-nitrosylation of GAPDH triggers nuclear translocation via binding to Siah1. Nitrosylated GAPDH stabilizes Siah1, an E3-ubiquitin ligage that mediates proteolysis of nuclear proteins leading to apoptosis. Expression: nitric oxide is formed from L-arginine by: 1) a constitutuve NO synthase (NO synthase-1 or NO synthase-3) in a) brain b) peripheral nerves c) endothelium (NO-synthase-3) d) bone e) granulocytes f) pancreatic beta cells 2) an inducible NO synthase (NO synthase-2) in a) Kupffer cells b) macrophages c) smooth muscle Laboratory: - nitric oxide in exhaled gas - fraction of exhaled nitric oxide - nitric oxide delivered.total volume

Interactions

molecular events

Related

nitric oxide expired gas determination nitrous oxide; laughing gas (N2O)

General

bioagent radical small molecule

Properties

Database Correlations

PUBCHEM correlations

References

  1. Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999
  2. Tidball J, 9th Annual UCLA Research Conference on Aging, June 17, 2004 (conference speaker)
  3. Sedlak TW, Snyder SH. Messenger molecules and cell death: therapeutic implications. JAMA. 2006 Jan 4;295(1):81-9. PMID: 16391220

Component-of

n2/nitric oxide