Effects of a Combination of Dietary Restriction and Exercise Training on Myocardial Apoptosis in Male Rats

Background and Objectives: Apoptosis plays a key role in pathogenesis of various cardiovascular diseases due to loss of terminally differentiated cardiac myocytes. Therefore, the aim of this study was to investigate effects of combined dietary restriction and aerobic training on indices of myocardial apoptosis in male rats. Materials and Methods: In this study, 32 three-month-old male rats were randomly divided into four major groups: 1) sedentary control (SED), 2)exercise training (EX), 3)diet restriction (DR) and 4)exercise training and diet restriction (EX+DR). All groups participated in the study for three months. Animals in SED and EX groups were fed ad libitum, while animals in DR and EX+DR groups were given access to 50% of the control animal diets. Animals in EX and EX+DR groups were involved in a three-month aerobic training program. Rat hearts were removed 48 h after the last training session. The Bax, Bcl-2 and caspase-3 gene expressions were analyzed using reverse-transcriptase polymerase chain reaction (RT-PCR). Data were analyzed using two-way ANOVA method. Results: Results showed that the Bax gene expression and Bax/Bcl-2 ratio were significantly lower in trained rats than untrained rats (P<0.05). Furthermore, Bcl-2 gene expression was significantly higher in EX+DR group than other groups (P<0.05). However, exercise training and dietary restriction did not affect caspase-3 gene expression (P>0.05).  Conclusions: Overall, it seems that combination of dietary restriction and exercise training results in a significant increase in anti-apoptotic Bcl-2 gene expression. However, further studies are needed to show effects of combined dietary restriction and exercise training on apoptosis.