Abstract:
Background. Irisin is the result of the proteolysis of fibronectin type III domain-containing protein 5, the levels of
which are determined by physical activity. Objective(s). This study aims to identify changes in FNDC5 gene
expression and the heart muscle irisin levels in male rats following 8 weeks resistance and endurance
trainings. Methods. Fifteen male rats (10-12 weeks old and 331.8±63.09 g in weight) were randomly assigned to
three groups: control, resistance and endurance training groups (5 in each group). The endurance group performed
activities on a treadmill for 8 weeks. The resistance group performed activities for 8 weeks on a one-meter-long
ladder with a slope of 85○. The control group did not undergo any particular training. Sampling was carried out 72 h
after the end of the training. The heart tissue were excised, cleaned and immediately frozen in liquid nitrogen, and
stored at -70○C. FNDC5 gene expression and the heart muscle irisin levels were measured using Real-Time PCR
and ELISA, respectively. Results. Kruskal-Wallis test showed a significant increase in the heart muscle FNDC5
expression in both training groups (P=0.004). One-way ANOVA showed a significant difference in heart muscle
irisin levels among the groups (p=0.004). Conclusion. It can be concluded that both resistance and endurance
training can significantly increase FNDC5 gene expression and the heart muscle irisin levels, suggesting that
physical activity can prevent and cure cardiovascular diseases
Machine summary:
"This study aims to identify changes in FNDC5 gene expression and the heart muscle irisin levels in male rats following 8 weeks resistance and endurance trainings.
It can be concluded that both resistance and endurance training can significantly increase FNDC5 gene expression and the heart muscle irisin levels, suggesting that physical activity can prevent and cure cardiovascular diseases.
Thus, the current survey revealed that most studies had investigated serum irisin levels in unhealthy, elderly or obese individuals (27, 28) and that in the field of physical training, the results on FNDC5 gene expression and the irisin levels in the heart muscle as a tissue with a high potential of metabolism which contains both types of brown and white obesity tissues (12), producing a larger amount of irisin in comparison with the skeletal muscle (29), has attracted less attention.
DISCUSSION The findings of the present study showed that 8 weeks' resistance and endurance activities caused a significant increase in FNDC5 gene expression and irisin levels in the heart tissue.
It seems that the irisin levels increase in male rats in adaptation to endurance training, which can then make white subcutaneous adipose tissue to get brown and increase energy expenditure via thermogenesis that is not induced by physical activity nor by food consumption (41).
Effect of Acute Resistance Training on Plasma Irisin Protein Level and Expression of Muscle FNDC5 and Adipose Tissue UCP1 Genes in Male Rats.
Effect of eight weeks’ resistance training on plasma irisin protein level and muscle FNDC5 and adipose tissue UCP1 genes expression in male rats."