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Contributions of nitric oxide synthases, dietary nitrite/nitrate, and other sources to the formation of NO signaling products

Milsom, Alexandra B., Fernandez, Bernadette O., Garcia-Saura, Maria F., Rodriguez, Juan and Feelisch, Martin (2012) Contributions of nitric oxide synthases, dietary nitrite/nitrate, and other sources to the formation of NO signaling products Antioxidants & Redox Signaling, 17, (3), pp. 422-432. (doi:10.1089/ars.2011.4156). (PMID:22133018).

Record type: Article


Mice lacking all three nitric oxide synthase (NOS) genes remain viable even though deletion of the major downstream target of NO, soluble guanylyl cyclase, is associated with a dramatically shortened life expectancy. Moreover, findings of relatively normal flow responses in eNOS knockouts are generally attributed to compensatory mechanisms including upregulation of remaining NOS isoforms, but the alternative possibility that dietary nitrite/nitrate (NOx) may contribute to basal levels of NO signaling has never been investigated.

Aim: The aim of the present study was to examine how NO signaling products (nitrosated and nitrosylated proteins) and NO metabolites (nitrite, nitrate) are affected by single NOS deletions and whether dietary NOx plays a compensatory role in any deficiency. Specifically, we sought to ascertain whether profound alterations of these products arise upon genetic deletion of either NOS isoform, inhibition of all NOS activity, NOx restriction, or all of the above.

Results: Our results indicate that while some significant changes do indeed occur, they are surprisingly moderate and compartmentalized to specific tissues. Unexpectedly, even after pharmacological inhibition of all NOSs and restriction of dietary NOx intake in eNOS knockout mice significant levels of NO-related products remain.

Innovation/Conclusion: These findings suggest that a yet unidentified source of NO, unrelated to NOSs or dietary NOx, may be sustaining basal NO signaling in tissues. Given the significance of NO for redox regulation in health and disease, it would seem to be important to identify the nature of this additional source of NO products as it may offer new therapeutic avenues for correcting NO deficiencies.

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e-pub ahead of print date: January 2012
Published date: 1 August 2012
Organisations: Clinical & Experimental Sciences


Local EPrints ID: 337517
ISSN: 1523-0864
PURE UUID: 4b7efc8c-7880-4ef4-9c38-92dcb6b96293
ORCID for Martin Feelisch: ORCID iD

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Date deposited: 26 Apr 2012 13:25
Last modified: 18 Jul 2017 06:02

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Author: Alexandra B. Milsom
Author: Bernadette O. Fernandez
Author: Maria F. Garcia-Saura
Author: Juan Rodriguez
Author: Martin Feelisch ORCID iD

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