Effect of Resistance Exercise and Vitamin C Intake on Expression of Telomerase Reverse Transcriptase and Telomere Repeat Binding Factor-2 Genes and the Diameter and Number of Myofibrils in Old Rats

Introduction: Cell aging is one of the most important and fundamental step in cellular behavior and reduces muscle mass and myofibrils. This study aims to investigate the effect of resistance exercise along with vitamin C consumption on the expression of Telomerase Reverse Transcriptase (TERT) and Telomere Repeat Binding Factor-2 (TRF2) genes and the diameter and number of skeletal muscle myofibrils in old male Wistar rats.  Methods: This is an experimental study using control groups. Twenty-five male Wistar rats (280-320 g) aged 24 weeks were randomly divided into five groups of young control, old + resistance exercise, old + vitamin intake, old + resistance exercise + vitamin intake, and old control. In the supplementation groups, rats received liposomal vitamin C daily by gavage per body weight. Weight attached to the tail gradually increased during 8 weeks of exercise (weeks 1 and 2 by 50%; weeks 3 and 4 by 50%; weeks 5 and 6 by 75%; weeks 7 and 8 by 100% of total body weight). Exercises were performed at 3-5 sets of 8-12 repetitions, 3 or 4 days a week. The Quantitative polymerase chain reaction method was used to evaluate the expression of TERT and TRF2 genes in muscle tissue. One-way ANOVA was used to examine the difference between the groups and Tukey’s post hoc test was used to determine between which groups the difference was significant. Results: Aging significantly reduced the expression of TERT, TRF2 genes and the diameter and number of myofibrils in skeletal muscle of rats (P= 0.001). Resistance exercise along with vitamin C intake had no significant effect on TERT and TRF2 expression (P≥0.05), but caused a significant increase in the diameter and number of myofibrils (P= 0.001).  Conclusion: Eight weeks of resistance exercise along with vitamin C supplementation can significantly increase the number and diameter of skeletal muscle myofibrils in old rats.