european college of sport science

Saturday, June 27th, 2009
08:30 - 10:00
Oral presentations
OP-SM02 Sports Medicine 2
IMPLICATION OF PPARS IN ANTI-ATHEROGENIC EFFECT OF SWIMMING EXERCISE IN APOLIPOPROTEIN E DEFICIENT
MICE (APOE-/-).
SZOSTAK, J., MIGUET-ALFONSI, C., PELLEGRIN, M., BOUZOURENE, K., BERTHELOT, A., MAZZOLAI, L., LAURANT, P.
UFR MEDECINE PHARMACIE
Introduction: Atherosclerosis is a chronic inflammatory disease. Physical exercise significantly reduces atherosclerosis lesions. However,
the precise mechanisms implicated are still unknown. Recent studies suggest that PPARs may have some anti-atherogenic effects. We
assess the hypothesis that exercise training reduces atherosclerosis in ApoE-/- deficient mice by increasing PPARs expression.
Methods: Male ApoE-/- deficient mice and normal C57Bl/6J mice were used. ApoE-/- mice were fed with a high fat diet and randomized
into tree groups: 1/ one exercise group underwent exercise training (60 min swimming, 5 times/week) for 13 weeks, 2/ one sedentary
group, and 3/ one supplementary exercise group supplied with an antagonist of PPAR-g Bisphenol Adiglycide
ether named BADGE. C57BL/6J mice were used as control and divided into two groups: control exercise and control sedentary.
Implications of PPARs in anti-atherogenic effects induced by exercise training are measured by quantification of PPAR mRNA by PCR
quantitative in aorta and muscle solaris.
Results: Atherosclerotic lesions in ApoE-/- deficient mice were significant decreased in ApoE-/- mice underwent protocol swimming for 13
weeks in comparison to the ApoE-/- sedentary group. In contrast, exercise in mice supplied with BADGE did not suppress the atherosclerotic
lesions. Exercise significantly increased expression of PPAR-g in aorta of ApoE-/- mice. Interestingly, the increased expression of
PPAR-g in vascular wall was inversely correlated with the atherosclerotic plaque area. PPAR-b and a were not modulated in response to
exercise training in aorta.
In soleus muscle, expression of PPAR-b was modulated by exercise training. Expression of PPAR-b in ApoE-/- mice was significantly
increased in response to exercise training. Moreover, expression of PPAR-b was significantly decreased in ApoE-/- mice in relation to
control mice. Interestingly, exercise in ApoE-/-mice supplied with BADGE, generated a significant decrease of PPAR-g and PPAR-b expression
in comparison to ApoE-/- mice underwent exercise.
Conclusion: exercise prevents the development of atherosclerotic lesions in aorta. Our findings indicate that PPAR-g are implicated in the
anti-atherogenic effects induced by physical exercise. In soleus, exercise training was associated with increased PPAR-b expression. This
may be due to an increase of the muscle oxidative capacity in response to exercise training.
EMG ACTIVITY OF ECCENTRIC QUADRICEPS MUSCLE ACTIONS IS GREATER DURING FLYWHEEL THAN WEIGHT STACK
TRAINING
NORRBRAND, L., POZZO, M., TESCH, P.A.
MID SWEDEN UNIVERSITY
Potential neural training adaptations in response to identical resistance exercise programs, using either an isoinertial flywheel device or a
traditional knee extension weight stack machine, were studied by measuring electromyographic (EMG) activity of superficial vastii muscles
pre and post 5 wk training.
Methods: Seventeen healthy, untrained men were assigned to 5 wks unilateral knee extension training (2-3 sessions/wk, 4 sets of 7
repetitions) using either a weight stack machine (WS; n=8) or a flywheel device (FW; n=9). Training specific mean and angle specific (90,
120 and 150° knee angle) EMG root mean square of mm. vastus lateralis (VL) and vastus medialis (VM) of concentric (CON) and eccentric
(ECC) actions were measured. EMG was normalized using EMG measured during a maximal isometric action as a reference.
Results: Pre training, grp FW showed greater overall angle specific normalized EMG of VL and VM (p