Endothelium-derived relaxing factor (EDRF) is produced and released by the endothelium that results in smooth muscle relaxation. The most well characterized is nitric oxide (NO), and some older sources consider the two terms to be equivalent.
It is released in response to a variety of chemical and physical stimuli. It causes the smooth muscle in the vessel wall to relax.
EDRF was discovered and characterized by Robert F. Furchgott, a winner of the Nobel Prize in Medicine in 1998 with his co-researchers Louis J. Ignarro and Ferid Murad.
According to Furchgott's website at SUNY Downstate Medical Center, "...we are investigating whether the endothelium-derived relaxing factor (EDRF) is simply nitric oxide or a mixture of substances".[1]
Although there is strong evidence that nitric oxide elicits vasodilation, there is some evidence tying this effect to neuronal rather than endothelial reactions.[2]
Terminology
According to some sources, EDRF refers not only to nitric oxide, but to other substances.[3][4] Endothelium actually produces a number of endothelial derived relaxing factors such as:
- prostacyclin (PGI2)[5]
- Endothelium-derived hyperpolarizing factor, or EDHF.[6][7] There is some evidence that EDHF is potassium.[8]
- Heme proteins from blood can also stimulate the inducible isoform of Heme oxygenase (HO-1 also known as heat shock protein 32) which produces Carbon monoxide that can relax smooth muscle.
Older candidate molecules included nitroxyl and hydroxylamine.[9]
The endothelium also produces a number of vasoconstricting agents and there is a balance of constricting and relaxing signals.
Some sources equate EDRF and nitric oxide.[10]
See also
References
- ^ "Robert Furchgott". http://www.hscbklyn.edu/pharmacology/furch.htm. Retrieved on 2008-12-21.
- ^ Chowdhary S, Townend JN (April 2001). "Nitric oxide and hypertension: not just an endothelium derived relaxing factor!". J Hum Hypertens 15 (4): 219–27. doi:. PMID 11319669. http://dx.doi.org/10.1038/sj.jhh.1001165.
- ^ MeSH Endothelium-Dependent+Relaxing+Factors
- ^ Resende AC, Ballejo G, Salgado MC (September 1998). "Role of non-nitric oxide non-prostaglandin endothelium-derived relaxing factor(s) in bradykinin vasodilation". Braz. J. Med. Biol. Res. 31 (9): 1229–35. PMID 9876291.
- ^ Waldron GJ, Cole WC (February 1999). "Activation of vascular smooth muscle K+ channels by endothelium-derived relaxing factors". Clin. Exp. Pharmacol. Physiol. 26 (2): 180–4. PMID 10065344. http://www3.interscience.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0305-1870&date=1999&volume=26&issue=2&spage=180.
- ^ Brandes RP, Schmitz-Winnenthal FH, Félétou M, et al. (August 2000). "An endothelium-derived hyperpolarizing factor distinct from NO and prostacyclin is a major endothelium-dependent vasodilator in resistance vessels of wild-type and endothelial NO synthase knockout mice". Proc. Natl. Acad. Sci. U.S.A. 97 (17): 9747–52. PMID 10944233. PMC: 16936. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=10944233.
- ^ Fitzgerald SM, Bashari H, Cox JA, Parkington HC, Evans RG (August 2007). "Contributions of endothelium-derived relaxing factors to control of hindlimb blood flow in the mouse in vivo". Am. J. Physiol. Heart Circ. Physiol. 293 (2): H1072–82. doi:. PMID 17468338. http://ajpheart.physiology.org/cgi/pmidlookup?view=long&pmid=17468338.
- ^ Savage D, Perkins J, Hong Lim C, Bund SJ (January 2003). "Functional evidence that K+ is the non-nitric oxide, non-prostanoid endothelium-derived relaxing factor in rat femoral arteries". Vascul. Pharmacol. 40 (1): 23–8. PMID 12646406. http://linkinghub.elsevier.com/retrieve/pii/S1537189102003178.
- ^ Feelisch M, te Poel M, Zamora R, Deussen A, Moncada S (March 1994). "Understanding the controversy over the identity of EDRF". Nature 368 (6466): 62–5. doi:. PMID 8107883. http://dx.doi.org/10.1038/368062a0.
- ^ endothelial-derived relaxing factor at Dorland's Medical Dictionary
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