Cited by 497Hemoglobin structure and functionNitric Oxide and Endothelin EffectsHeme Oxygenase-1 and Carbon Monoxide

Hypoxia, red blood cells, and nitrite regulate NO-dependent hypoxic vasodilation

Open access
Crawford, J. H.·2006·Blood

Abstract

Local vasodilation in response to hypoxia is a fundamental physiologic response ensuring oxygen delivery to tissues under metabolic stress. Recent studies identify a role for the red blood cell (RBC), with hemoglobin the hypoxic sensor. Herein, we investigate the mechanisms regulating this process and explore the relative roles of adenosine triphosphate, S-nitrosohemoglobin, and nitrite as effectors. We provide evidence that hypoxic RBCs mediate vasodilation by reducing nitrite to nitric oxide (NO) and ATP release. NO dependence for nitrite-mediated vasodilation was evidenced by NO gas formation, stimulation of cGMP production, and inhibition of mitochondrial respiration in a process sensitive to the NO scavenger C-PTIO. The nitrite reductase activity of hemoglobin is modulated by heme deoxygenation and heme redox potential, with maximal activity observed at 50% hemoglobin oxygenation (P(50)). Concomitantly, vasodilation is initiated at the P(50), suggesting that oxygen sensing by hemoglobin is mechanistically linked to nitrite reduction and stimulation of vasodilation. Mutation of the conserved beta93cys residue decreases the heme redox potential (ie, decreases E(1/2)), an effect that increases nitrite reductase activity and vasodilation at any given hemoglobin saturation. These data support a function for RBC hemoglobin as an allosterically and redox-regulated nitrite reductase whose "enzyme activity" couples hypoxia to increased NO-dependent blood flow.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1182/blood-2005-07-2668

Cites

60 of 60 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Accumulating studies demonstrate production of bioavailable NO from incubation of erythrocytes with nitrite.

    “Although theoretical calculations suggest that this type of NO escape should be limited, accumulating studies by many research groups now demonstrate the production of bioavailable NO generated from the incubation of erythrocytes with nitrite (185, 196, 883, 975).”
  • Relaxation by nitrite and red blood cells was associated with cGMP formation and dependent on Hb oxygen affinity, with maximal effect occurring near the Hb p50, consistent with the notion that R-state Hb reduces nitrite more effectively than T-state Hb.

    “Relaxation by nitrite and red blood cells was associated with cGMP formation and dependent on Hb oxygen affinity, with maximal effect occurring near the Hb p50, consistent with the notion that R-state Hb reduces nitrite more effectively than T-state Hb [109].”

    From Mechanisms of nitrite bioactivation (2014) · cites this paper as [109]

  • At oxygen tensions of 15 and 25 mmHg as little as 200 nM nitrite was subsequently shown to effect relaxation in aortic rings in the presence of red blood cells and relaxation was abrogated by the NO scavenger CPTIO.

    “At oxygen tensions of 15 and 25 mmHg as little as 200 nM nitrite was subsequently shown to effect relaxation in aortic rings in the presence of red blood cells and relaxation was abrogated by the NO scavenger CPTIO [109].”

    From Mechanisms of nitrite bioactivation (2014) · cites this paper as [109]

  • Differential reactivity of nitrite reduction versus oxidation controlled by oxygen tension underlies the model in which nitrite selectively produces NO during graded hypoxia.

    “This differential reactivity of nitrite reduction versus oxidation being controlled by oxygen tension (i.e. presence of deoxygenated vs oxygenated hemoglobin / myoglobin) illustrates the biochemical mechanism underlying the proposed model in which nitrite can selectively produce NO during graded hypoxia [5, 25-28].”
  • Evidence for a role for NO is dependent largely on attenuation of responses by the NO-scavenger CPTIO and measurement of nitrite-dependent increases in cGMP levels.

    “Evidence for a role for NO is dependent largely on attenuation of responses by the NO-scavenger CPTIO [25, 26, 52, 100] and measurement of nitrite-dependent increases in cGMP levels[26, 101].”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Patel RP, Hogg N, Spencer NY, Kalyanaraman B, Matalon S, Darley-Usmar VM. Biochemical char- acterization of human S-nitrosohemoglobin: ef- fects on oxygen binding and transnitrosation. J Biol Chem. 1999;274:15487-15492.

Cited by

Sorted by citations

Authors
Crawford, J. H.
Affiliations
University of Alabama at Birmingham (US)
Corresponding author
Crawford, J. H.
Venue
Blood
Published
2006-01-15
Volume
107
Issue
2
Pages
566-574
ISSN
  • 0006-4971 (ISSN-L)
  • 1528-0020
OpenAlex
W2138011583
Cited by
497
References
60
Citations by year
2026: 5 · 2025: 7 · 2024: 12 · 2023: 13 · 2022: 7 · 2021: 24 · 2020: 16 · 2019: 13 · 2018: 24 · 2017: 27 · 2016: 17 · 2015: 28 · 2014: 24 · 2013: 34 · 2012: 39
FWCI
14.51
Type
journal article
Language
en
Open access
Locations
  • Blood (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • American Heart Association
  • National Institutes of Health (HL70146)
  • National Heart, Lung, and Blood Institute (R01HL070146, HL 70146, HL24525)
  • National Institute of General Medical Sciences (T32GM008361, T32 GM 08361)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Hemoglobin structure and function
  • Health Sciences › Medicine › Physiology › Nitric Oxide and Endothelin Effects
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Heme Oxygenase-1 and Carbon Monoxide
Keywords
hypoxic vasodilation, erythrocytes, nitrite, nitric oxide, hemoglobin, nitrite reductase, heme redox potential, ATP release, cyclic GMP, mitochondrial respiration, oxygen sensing, oxygen delivery
MeSH terms
Adenosine Triphosphate, Allosteric Regulation, Erythrocytes, Cyclic GMP, Heme, Hemoglobins, Humans, Mitochondria, Mutation, Nitric Oxide, Nitrite Reductases, Nitrites, Oxidation-Reduction, Oxygen, Respiration, Vasodilation, Cell Hypoxia

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review