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


METHODS
We 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.


RESULTS
There 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.


CONCLUSIONS
Patients with the 894G>T polymorphism had lower vascular reactivity after a single bout of exercise.
Neves
Fabricia J
FJ
Department of Physiology and Pharmacology & Postgraduate Program in Cardiovascular Sciences, Fluminense Federal University, Niterói, Brazil.
Silva
Bruno M
BM
Rocha
Natália G
NG
Sales
Allan R K
AR
Ribeiro
Georgina S
GS
Nóbrega
Antonio C
AC
D000328:Adult; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005838:Genotype; D006439:Hemodynamics / Q000235:genetics; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D006940:Hyperemia / Q000235:genetics*; D008297:Male; D009569:Nitric Oxide / Q000235:genetics; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D010991:Plethysmography; D011110:Polymorphism, Genetic
D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III