TY - JOUR
T1 - Total nitrogen oxide following exercise testing reflects endothelial function and discriminates health status
AU - Allen, Jason D.
AU - Cobb, Frederick R.
AU - Kraus, William E.
AU - Gow, Andrew J.
PY - 2006/9/1
Y1 - 2006/9/1
N2 - Nitric oxide (NO) bioavailability is important in vascular health, but unsuitable as a clinical measure due to biological oxidation. Total nitrogen oxides (NOx) are stable but background nitrate levels make it difficult to detect disease-based variation. We investigated the clinical discriminatory value of NOx as it relates to exercise capability (VO2peak) and brachial artery reactivity (BAR, an NO-dependent measure of endothelial health), in healthy (H), increased risk (RF), and known cardiovascular disease (CVD) subjects. BAR was measured using forearm occlusion/hyperemia stimulus. Subjects performed a maximal graded exercise test (GXT). Blood at rest, exercise termination, and 10 min into recovery was mixed equally with 0.1 M NaOH at 4°C, filtered, and stored at -70°C. NOx was measured by chemiluminescence. Seven of the RF group then exercise-trained for 6 months prior to retesting. The H group (n = 12) was younger, had higher VO2peak, HDL levels, and baseline NOx values than the RF (n = 15) and CVD (n = 10) groups. NOx increased from baseline to recovery in the H group only (75.85 ± 19.04 μM vs 97.76 ± 31.93 μM; P ≤ 0.01). BAR was greater in the H versus CVD group (7.24 ± 3.78% vs 2.59 ± 3.53%; P ≤ 0.01). The relation between VO2peak and NOx recovery was significant across groups (r = 0.71, P ≤ 0.01). Following training the RF subjects (n = 7) increased VO2peak (29.98 ± 6.74 to 33.08 ± 5.57 ml kg-1 min-1; P ≤ 0.05), BAR (3.19 ± 3.96 to 6.86 ± 4.81%; P ≤ 0.05), and recovery NOx (18.29 ± 6.46 to 66.48 + 21.11 μM; P ≤ 0.01). These findings suggest that plasma NOx following GXT discriminate cardiovascular disease status, are related to regional endothelial function, and respond favorably to exercise training.
AB - Nitric oxide (NO) bioavailability is important in vascular health, but unsuitable as a clinical measure due to biological oxidation. Total nitrogen oxides (NOx) are stable but background nitrate levels make it difficult to detect disease-based variation. We investigated the clinical discriminatory value of NOx as it relates to exercise capability (VO2peak) and brachial artery reactivity (BAR, an NO-dependent measure of endothelial health), in healthy (H), increased risk (RF), and known cardiovascular disease (CVD) subjects. BAR was measured using forearm occlusion/hyperemia stimulus. Subjects performed a maximal graded exercise test (GXT). Blood at rest, exercise termination, and 10 min into recovery was mixed equally with 0.1 M NaOH at 4°C, filtered, and stored at -70°C. NOx was measured by chemiluminescence. Seven of the RF group then exercise-trained for 6 months prior to retesting. The H group (n = 12) was younger, had higher VO2peak, HDL levels, and baseline NOx values than the RF (n = 15) and CVD (n = 10) groups. NOx increased from baseline to recovery in the H group only (75.85 ± 19.04 μM vs 97.76 ± 31.93 μM; P ≤ 0.01). BAR was greater in the H versus CVD group (7.24 ± 3.78% vs 2.59 ± 3.53%; P ≤ 0.01). The relation between VO2peak and NOx recovery was significant across groups (r = 0.71, P ≤ 0.01). Following training the RF subjects (n = 7) increased VO2peak (29.98 ± 6.74 to 33.08 ± 5.57 ml kg-1 min-1; P ≤ 0.05), BAR (3.19 ± 3.96 to 6.86 ± 4.81%; P ≤ 0.05), and recovery NOx (18.29 ± 6.46 to 66.48 + 21.11 μM; P ≤ 0.01). These findings suggest that plasma NOx following GXT discriminate cardiovascular disease status, are related to regional endothelial function, and respond favorably to exercise training.
KW - Cardiovascular disease
KW - Endothelium
KW - Exercise
KW - Nitric oxide
KW - NO
KW - VO
UR - http://www.scopus.com/inward/record.url?scp=33746817045&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33746817045&partnerID=8YFLogxK
U2 - 10.1016/j.freeradbiomed.2006.05.016
DO - 10.1016/j.freeradbiomed.2006.05.016
M3 - Article
C2 - 16895794
AN - SCOPUS:33746817045
VL - 41
SP - 740
EP - 747
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
SN - 0891-5849
IS - 5
ER -