Background and Aim: Cardiovascular diseases are among the main causes of mortality in the elderly. Signaling of mitochondrial biogenesis has a crucial role in cardiovascular energy homeostasis. The purpose of this study was to compare the effect of high and moderate intensity resistance training on the myocardial gene expression of some mitochondrial signaling molecules including AMPK, PGC-1α, TFAM and cytochrome C in the elderly rats.
Methods: Twenty-five male Wistar rats with 23 months old and 437 g average weight were randomly assigned to control (n = 8), resistance training (RT) with high intensity [HRT, 80% of maximum voluntary carrying capacity] (n = 8), and moderate intensity [MRT, 60% of maximum voluntary carrying capacity] (n = 9). RT included 5 days/week of climbing a ladder for 8 weeks. Seventy-two hours after the last training session, myocardial gene expression of AMPK, PGC-1α, TFAM and cytochrome C were measured by Real Time Polymerase Chain Reaction. One-way analysis of variance and Tukey post-hoc test were used for statistical analyses and p <0.05 was considered the significant level.
Results: PGC-1α gene expression significantly increased in both HRT and MRT groups compared to the control group (p < 0.05). MRT significant increased  cytochrome C gene expression, compared to the control group (p < 0.05).
Conclusion: In elderly rats, HRT and MRT can improve PGC-1α myocardial expression, wheras MRT improves the cytochrome C myocardial expression. These effects can be useful in improving the energy homeostasis of myocardial cells in the elderly.