title: Exercise training improves muscle vasodilatation in individuals with T786C polymorphism of endothelial nitric oxide synthase gene.
abstract: Allele T at promoter region of the eNOS gene has been associated with an increase in coronary disease mortality, suggesting that this allele increases susceptibility for endothelial dysfunction. In contrast, exercise training improves endothelial function. Thus, we hypothesized that: 1) Muscle vasodilatation during exercise is attenuated in individuals homozygous for allele T, and 2) Exercise training improves muscle vasodilatation in response to exercise for TT genotype individuals. From 133 preselected healthy individuals genotyped for the T786C polymorphism, 72 participated in the study: TT (n = 37; age 27 ± 1 yr) and CT+CC (n = 35; age 26 ± 1 yr). Forearm blood flow (venous occlusion plethysmography) and blood pressure (oscillometric automatic cuff) were evaluated at rest and during 30% handgrip exercise. Exercise training consisted of three sessions per week for 18 wk, with intensity between anaerobic threshold and respiratory compensation point. Resting forearm vascular conductance (FVC, P = 0.17) and mean blood pressure (P = 0.70) were similar between groups. However, FVC responses during handgrip exercise were significantly lower in TT individuals compared with CT+CC individuals (0.39 ± 0.12 vs. 1.08 ± 0.27 units, P = 0.01). Exercise training significantly increased peak VO(2) in both groups, but resting FVC remained unchanged. This intervention significantly increased FVC response to handgrip exercise in TT individuals (P = 0.03), but not in CT+CC individuals (P = 0.49), leading to an equivalent FVC response between TT and CT+CC individuals (1.05 ± 0.18 vs. 1.59 ± 0.27 units, P = 0.27). In conclusion, exercise training improves muscle vasodilatation in response to exercise in TT genotype individuals, demonstrating that genetic variants influence the effects of interventions such as exercise training.
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, Cerqueira César, São Paulo, SP, Brazil.
authors.forename: Marcelo V
authors.initials: MV
authors.lastname: Negrao
authors.forename: Cleber R
authors.initials: CR
authors.lastname: Alves
authors.forename: Guilherme B
authors.initials: GB
authors.lastname: Alves
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Pereira
authors.forename: Rodrigo G
authors.initials: RG
authors.lastname: Dias
authors.forename: Mateus C
authors.initials: MC
authors.lastname: Laterza
authors.forename: Gloria F
authors.initials: GF
authors.lastname: Mota
authors.forename: Edilamar M
authors.initials: EM
authors.lastname: Oliveira
authors.forename: Vinícius
authors.initials: V
authors.lastname: Bassaneze
authors.forename: Jose E
authors.initials: JE
authors.lastname: Krieger
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Negrao
authors.forename: Maria Urbana P B
authors.initials: MU
authors.lastname: Rondon
mesh_terms: D000293:Adolescent; D000328:Adult; D015444:Exercise / Q000502:physiology*; D005260:Female; D005838:Genotype; D006339:Heart Rate / Q000235:genetics / Q000502:physiology; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply*; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D014664:Vasodilation / Q000235:genetics / Q000502:physiology*; D055815:Young Adult
chemical_list: D052250:Nitric Oxide Synthase Type III