Format

Send to:

Choose Destination
See comment in PubMed Commons below
Br J Sports Med. 2007 Oct;41(10):669-73; discussion 673. Epub 2007 May 11.

Nitric oxide synthase-derived plasma nitrite predicts exercise capacity.

Author information

  • 1Department of Medicine, Division of Cardiology, Pulmonary Diseases and Angiology, University Hospital Aachen, Pauwelsstr 30, 52074 Aachen, Germany. trassaf@ukaachen.de

Abstract

BACKGROUND:

Nitrite is the main oxidation product of nitric oxide (NO) in plasma. It sensitively reflects changes in endothelial NO synthase (eNOS) activity under fasting conditions and serves as an endocrine NO donor, contributing to the regulation of blood flow through reaction with haemoglobin. As NO is necessary to maintain an adequate vascular response to the increased demands of blood flow, it is believed to be important for vasodilation induced by exercise.

OBJECTIVE:

To investigate whether the capacity of the vasculature to produce nitrite is associated with exercise performance.

DESIGN:

With the use of chemiluminescence detection, nitrite concentrations in 55 healthy subjects (mean (SEM) age 40 (2) years; 22 men) were studied before and after an exercise test, and endothelial function was determined by measuring flow-mediated dilation of the brachial artery using high-resolution ultrasound. In a subset of subjects, the NOS inhibitor, N(G)-monomethyl-L-arginine, was applied to elucidate the effect of eNOS on changes in nitrite.

RESULTS:

Exercise significantly (p<0.001) increased plasma nitrite from 97 (6) to 125 (8) nM. The relative increase in plasma nitrite was related to flow-mediated dilation (6.1 (0.3)%; r = 0.36; p = 0.01). N(G)-Monomethyl-L-arginine blocked increases in nitrite. Post-exercise nitrite concentration correlated with exercise performance, as determined by maximally reached stress power (r = 0.37; p<0.007), and inversely with age. Multivariate analysis showed that both age and post-exercise nitrite concentration were independent predictors of stress endurance and power.

CONCLUSION:

The results suggest a role for plasma nitrite in the adaptation of haemodynamics during exercise. An impaired increase in plasma nitrite may limit exercise capacity.

PMID:
17496072
[PubMed - indexed for MEDLINE]
PMCID:
PMC2465183
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk