THE EFFECT OF MODERATE-INTENSITY ENDURANCE TRAINING ON CORTISOL LEVELS, MEF-2C AND MMP-2 GENE EXPRESSION IN MALE RATS MYOCARDIUM: INTERVENTIONAL AND EXPERIMENTAL STUDY

The structural and functional adaptations of the heart muscle to various stresses
cause fundamental changes in this tissue, and also exercise training as a desirable stressor increases the
hypertrophy and angiogenesis of heart tissue. Therefore, the aim of the present study was to investigate
the effect of six weeks of moderate-intensity endurance training on the levels of cortisol, MEF-2C, and
MMP-2 gene expression in Wistar male myocardium.
Materials & Methods: Twenty adult male rats, 10-weeks old, weighing 243±8.2 g were examined in
this experimental study. Animals were divided into two groups of 10 per group: training and control.
The animals underwent six weeks of moderate-intensity endurance training for five days a week on a
treadmill. Blood samples were taken before the first session and 24 hours after the last training session
and cardiac tissue were extracted for measurement of MEF-2C and MMP-2 gene expression after the
last session. Covariance analysis was used to compare the differences between cortisol level changes
and independent t-test with a significant level of p<0/05 was used to examine changes in gene expression
of MEF-2C and MMP-2.
Results: After six weeks of endurance training cortisol levels had no different change compared to
pretest and control group with the significant level of (P=0.342) and (P=0.08), respectively. However,
gene expression of both factors related to the angiogenesis of cardiac tissue MEF-2C and MMP-2
increased compared to the control group (p=0.016 and p=0.021, respectively).
Conclusion: It can be concluded that moderate-intensity endurance training has a positive effect on
hypertrophy, and angiogenesis of rats' heart tissue and it seems that endurance training can be effective
in preventing cardiovascular disease and it can cause beneficial structural adaptations for individuals