Effect of the 894G>T polymorphism of the endothelial nitric oxide synthase on vascular reactivity following maximal dynamic exercise

• Published in: Journal of hypertension Vol. 28; no. 4; pp. 764 - 770
• Main Authors: Neves, Fabricia J, Silva, Bruno M, Rocha, Natália G, Sales, Allan RK, Ribeiro, Georgina S, Nóbrega, Antonio C
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins, Inc 01-04-2010; Lippincott Williams & Wilkins
• Subjects: Adult; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Clinical manifestations. Epidemiology. Investigative techniques. Etiology; Exercise - physiology; Exercise Test; Female; Genotype; Hemodynamics - genetics; Heterozygote; Homozygote; Humans; Hyperemia - genetics; Male; Medical sciences; Nitric Oxide - genetics; Nitric Oxide Synthase Type III - genetics; Plethysmography; Polymorphism, Genetic; Physical exercise; Hypertension; Enzyme; Nitric oxide; Cardiovascular disease; exercise; Oxidoreductases; Nitric-oxide synthase; Plethysmography; Polymorphism
• ISSN: 0263-6352; 1473-5598
• DOI: 10.1097/HJH.0b013e328334f55c

BACKGROUNDConsidering that the role of nitric oxide as a vasodilator is increased after an acute bout of exercise and that the 894G>T polymorphism of the endothelial nitric oxide synthase seems to reduce the nitric oxide release in response to shear stress, the present study investigated the 894G>T polymorphism in relation to vascular reactivity following maximal dynamic exercise.
METHODWe studied 110 healthy volunteers (wild-type group 45.5% and polymorphic group 54.5%). The protocol included vascular reactivity assessment at baseline and during reactive hyperemia, before, 10, 60 and 120 min after a maximal cardiopulmonary exercise test. Genomic DNA was extracted from blood samples to determine the 894G>T polymorphism.
RESULTSThere were no differences between the wild-type and polymorphic groups concerning anthropometric, metabolic and hemodynamic characteristics. Blood flow, before maximal exercise, was similar between the wild-type and the polymorphic groups. The polymorphic group presented lower vascular reactivity regardless of time (P = 0.019 for group main effect), and posthoc analysis revealed that polymorphic patients had lower values than wild-type only at the 120 min measurement (P = 0.002). Concerning within-group analysis, vascular reactivity increased at 10 min after exercise (P = 0.029) returning to baseline at 120 min (P = 0.005) in the polymorphic group.
CONCLUSIONPatients with the 894G>T polymorphism had lower vascular reactivity after a single bout of exercise.