european college of sport science

OP-MB02 Molecular Biology 2
ship are lacking (3). One primary aim of the present study was to test this hypothesis and whether there is a further interaction of oxidative
stress (OS) and antioxidant (AO) responses following an Ironman (IM) triathlon.
Methods: Blood samples were taken from 42 male triathletes (mean±SD: age: 35.3±7.0 yr, cycling VO2 peak: 56.6±6.2 ml kg-1 min-1) 2
days (d) before an IM, then immediately, 1, 5, and 19 d post-race. Blood was analysed for inflammatory, immune-endocrine responses,
muscle damage, OS markers, endogenous and exogenous AOs and plasma AO capacity (1, 2). 20 and 28 subjects were randomly
selected for the assessment of DNA and chromosomal stability in lymphocytes measured via the cytokinesis block micronucleus cytome
(CBMN Cyt) (4) and the single cell gel electrophoresis (SCGE) assays (including lesion specific enzymes), respectively. Correlation, onefactorial
ANOVA and post hoc analyses were applied to assess potential associations.
Results: The IM induced a pronounced initial systemic inflammatory response (2). Concomitantly with a transient increase in most OS
markers there were strong AO responses (1). Increased DNA instability was detected by the SCGE technique, but these changes were
temporarily. Endpoints within the CBMN Cyt assay actually decreased post-race (4). No associations were found between endpoints of
DNA stability and inflammation or muscle damage (3). Endonuclease III-sensitive sites correlated negatively with the oxygen radical
absorbance capacity immediately (r= -0.54; P 0.05) were recorded in blood insulin or total or phosphorylated Akt
at any time point or between genders. While there were no sex differences in total 4E-BP1, the phosphor of 4E-BP1 was significantly higher
at rest in males compared to females (P < 0.05). Following exercise, there was a significant reduction in phosphorylation of 4E-BP1 in the
males but not the females. By 2 h post-exercise phosphorylation of 4E-BP1 had returned to resting levels for both males and females.
While there were no differences in the resting or post-exercise muscle Akt or other physiological measures such as HR, blood lactate or
blood insulin, the females had a reduced phosphorylation of 4E-BP1 at rest compared to the males. Additionally there was no significant
change in phosphorylation of 4E-BP1 in the females following exercise. However, similar to studies using males and performing resistance
exercise, the males in the present study had a reduction in phosphorylation of 4E-BP1 post exercise, which returned to basal levels
by 2 h. These results indicate there may be small sex differences in the translational machinery regulating muscle mass. The lack of
change in phosphorylation of 4E-BP1 following exercise in females may be due to sex differences in activation of AMPKinase, previously
reported following intense exercise.
THE AKT-DEPENDENT ENDOTHELIAL NITRIC OXIDE SYNTHASE (ENOS) PHOSPHORYLATION IS NOT THE PRIMARY MO-
LECULAR MECHANISM UNDERLYING THE BENEFICIAL EFFECT OF LONG-TERM EXERCISE ON ATHEROSCLEROSIS
PELLEGRIN, M., MIGUET-ALFONSI, C., BOUZOURENE, K., AUBERT, J.F., BERTHELOT, A., MAZZOLAI, L., LAURANT, P.
SERVICE OF VASCULAR MEDICINE AND EXERCISE PREVENTION INNOVATION AND TECHNICO-SPORTING WATCHING DEPARTMENT
Introduction: Exercise reduces atherosclerosis extension in humans and animal models (Niebauer et al., 1997; Pellegrin et al., 2007).
However, the precise anti-atherosclerotic molecular mechanisms of exercise are still unclear. Exercise-induced increase of vascular
eNOS phosphorylation through the protein kinase Akt has been regarded as a vasculoprotective mechanism in patients with coronary
artery disease (Hambrecht et al., 2003). Therefore, the aim of this study was to assess whether this regulatory pathway underlie the
beneficial effect of exercise in experimental atherosclerosis using Apolipoprotein E-deficient mice (ApoE-/-) mice.
Methods: Hypercholesterolemic ApoE-/- mice were subjected to 24-week swimming exercise (50 min/day; 5 days/week). A group of
sedentary animals were used as controls. Morphometry and characteristics of plaque stability were assessed in plaques from aortic
sinus by immunohistochemistry. Expression of eNOS, eNOS phosphorylation at Ser1177, Akt, and Akt phosphorylation at Ser473 were
measured in aortas by western blot.
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ANNUAL CONGRESS OF THE EUROPEAN COLLEGE OF SPORT SCIENCE