The University of Southampton
University of Southampton Institutional Repository

Tissue processing of nitrite in hypoxia: an intricate interplay of nitric oxide-generating and -scavenging systems

Tissue processing of nitrite in hypoxia: an intricate interplay of nitric oxide-generating and -scavenging systems
Tissue processing of nitrite in hypoxia: an intricate interplay of nitric oxide-generating and -scavenging systems
Although nitrite (NO(2)(-)) and nitrate (NO(3)(-)) have been considered traditionally inert byproducts of nitric oxide (NO) metabolism, recent studies indicate that NO(2)(-) represents an important source of NO for processes ranging from angiogenesis through hypoxic vasodilation to ischemic organ protection. Despite intense investigation, the mechanisms through which NO(2)(-) exerts its physiological/pharmacological effects remain incompletely understood. We sought to systematically investigate the fate of NO(2)(-) in hypoxia from cellular uptake in vitro to tissue utilization in vivo using the Wistar rat as a mammalian model. We find that most tissues (except erythrocytes) produce free NO at rates that are maximal under hypoxia and that correlate robustly with each tissue's capacity for mitochondrial oxygen consumption. By comparing the kinetics of NO release before and after ferricyanide addition in tissue homogenates to mathematical models of NO(2)(-) reduction/NO scavenging, we show that the amount of nitrosylated products formed greatly exceeds what can be accounted for by NO trapping. This difference suggests that such products are formed directly from NO(2)(-), without passing through the intermediacy of free NO. Inhibitor and subcellular fractionation studies indicate that NO(2)(-) reductase activity involves multiple redundant enzymatic systems (i.e. heme, iron-sulfur cluster, and molybdenum-based reductases) distributed throughout different cellular compartments and acting in concert to elicit NO signaling. These observations hint at conserved roles for the NO(2)(-)-NO pool in cellular processes such as oxygen-sensing and oxygen-dependent modulation of intermediary metabolism.
0021-9258
33927-33934
Feelisch, Martin
8c1b9965-8614-4e85-b2c6-458a2e17eafd
Fernandez, Bernadette O.
27babc73-7646-4908-86e2-6c29d79fb938
Bryan, Nathan S.
709ff51c-c864-4862-9e3f-c5cfd3961025
Garcia-Saura, Maria Francisca
f8c30d3b-c0d5-4d1c-9280-96aca7072eb3
Bauer, Selena
2cfecfcf-a31c-4366-a86b-398b8b360495
Whitlock, David R.
38ccbaf4-bdb9-4f7c-a6fb-8b27b30a7f8e
Ford, Peter C.
a752d252-18ac-4b00-8c4b-c36f28cf15df
Janero, David R.
a3c7e843-32f6-4f64-853b-717947c978f9
Rodriguez, Juan
055ad15f-3cf3-4366-a11c-9a313cf2fa60
Ashrafian, Houman
5bfc2cf7-6f24-4e24-9f9b-d217cfc94566
Feelisch, Martin
8c1b9965-8614-4e85-b2c6-458a2e17eafd
Fernandez, Bernadette O.
27babc73-7646-4908-86e2-6c29d79fb938
Bryan, Nathan S.
709ff51c-c864-4862-9e3f-c5cfd3961025
Garcia-Saura, Maria Francisca
f8c30d3b-c0d5-4d1c-9280-96aca7072eb3
Bauer, Selena
2cfecfcf-a31c-4366-a86b-398b8b360495
Whitlock, David R.
38ccbaf4-bdb9-4f7c-a6fb-8b27b30a7f8e
Ford, Peter C.
a752d252-18ac-4b00-8c4b-c36f28cf15df
Janero, David R.
a3c7e843-32f6-4f64-853b-717947c978f9
Rodriguez, Juan
055ad15f-3cf3-4366-a11c-9a313cf2fa60
Ashrafian, Houman
5bfc2cf7-6f24-4e24-9f9b-d217cfc94566

Feelisch, Martin, Fernandez, Bernadette O., Bryan, Nathan S., Garcia-Saura, Maria Francisca, Bauer, Selena, Whitlock, David R., Ford, Peter C., Janero, David R., Rodriguez, Juan and Ashrafian, Houman (2008) Tissue processing of nitrite in hypoxia: an intricate interplay of nitric oxide-generating and -scavenging systems. The Journal of Biological Chemistry, 283 (49), 33927-33934. (doi:10.1074/jbc.M806654200). (PMID:18835812)

Record type: Article

Abstract

Although nitrite (NO(2)(-)) and nitrate (NO(3)(-)) have been considered traditionally inert byproducts of nitric oxide (NO) metabolism, recent studies indicate that NO(2)(-) represents an important source of NO for processes ranging from angiogenesis through hypoxic vasodilation to ischemic organ protection. Despite intense investigation, the mechanisms through which NO(2)(-) exerts its physiological/pharmacological effects remain incompletely understood. We sought to systematically investigate the fate of NO(2)(-) in hypoxia from cellular uptake in vitro to tissue utilization in vivo using the Wistar rat as a mammalian model. We find that most tissues (except erythrocytes) produce free NO at rates that are maximal under hypoxia and that correlate robustly with each tissue's capacity for mitochondrial oxygen consumption. By comparing the kinetics of NO release before and after ferricyanide addition in tissue homogenates to mathematical models of NO(2)(-) reduction/NO scavenging, we show that the amount of nitrosylated products formed greatly exceeds what can be accounted for by NO trapping. This difference suggests that such products are formed directly from NO(2)(-), without passing through the intermediacy of free NO. Inhibitor and subcellular fractionation studies indicate that NO(2)(-) reductase activity involves multiple redundant enzymatic systems (i.e. heme, iron-sulfur cluster, and molybdenum-based reductases) distributed throughout different cellular compartments and acting in concert to elicit NO signaling. These observations hint at conserved roles for the NO(2)(-)-NO pool in cellular processes such as oxygen-sensing and oxygen-dependent modulation of intermediary metabolism.

This record has no associated files available for download.

More information

e-pub ahead of print date: 8 October 2008
Published date: 5 December 2008
Organisations: Clinical & Experimental Sciences

Identifiers

Local EPrints ID: 337522
URI: http://eprints.soton.ac.uk/id/eprint/337522
ISSN: 0021-9258
PURE UUID: 17f457d3-148d-4afb-bf36-de7d479b94f8
ORCID for Martin Feelisch: ORCID iD orcid.org/0000-0003-2320-1158

Catalogue record

Date deposited: 26 Apr 2012 13:38
Last modified: 15 Mar 2024 03:41

Export record

Altmetrics

Contributors

Author: Martin Feelisch ORCID iD
Author: Bernadette O. Fernandez
Author: Nathan S. Bryan
Author: Maria Francisca Garcia-Saura
Author: Selena Bauer
Author: David R. Whitlock
Author: Peter C. Ford
Author: David R. Janero
Author: Juan Rodriguez
Author: Houman Ashrafian

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×