The Effect of Endurance Training on Ghrelin, Insulin, Glucose and Estrogen in Male Rats

Ghrelin is a 28-amino-acid peptide hormone that is secreted primarily by stomach cells with lesser amounts secreted by other cells (including the hypothalamus). The aim of present study was to examine the effects of 8 weeks aerobic training with different durations on resting plasma Ghrelin levels in male rats. Fifty adult Wistar male rats (6-8 weeks old, 270±10 g) were selected and randomly divided into five groups: 30, 60 and 90 min training, sham and control groups. All experimental groups performed an 8-week treadmill running program at the same velocity at 0 gradients for 30, 60 or 90 min/day, 5 days/week. The concentration of ghrelin in blood samples was assessed after 8 weeks and 72 hours following the final training session. The ghrelin concentration was measured by ELISA. Possible statistically significant differences between groups after the exercise training intervention was determined by one way ANOVA, and LSD test was used for a post hoc analysis. Resting levels of ghrelin concentration were unchanged after training. Similarly, there was no observed change in the insulin and glucose concentrations compared with the control group. However there was a significant difference in estrogen when compared with the control group. The data suggest that body weight reduction is amplified by exercise-induced and increases in plasma estradiol and a moderate duration exercise program.