Effect of 8 Weeks Endurance Training With Two Different Durations on Plasma HDL-Ghrelin in Male Rats

Ghrelin, produced and secreted mainly from the stomach, is a potent stimulator of growth hormone, appetite, and plays a role in energy balance control. There is increased risk of metabolic syndrome with increased LDL-C and TC levels and decreased HDL-C, with lower ghrelin concentrations. The purpose of this study was to compare the effect of different 8-week endurance training regimens on HDL-Ghrelin. Thirty Wistar male rats, 6-8 weeks of age, were randomly assigned to 3 groups of 10 rats, including two training groups with either 30 or 90 min of exercise, and a control group. Experimental groups were trained for 8 weeks, 5 days per week at 20m/min for 30 or 90 min. Rats were sacrificed 72 h after the last training session and plasma samples were collected for determining HDL-Ghrelin, HDL-C, HDL-2, HDL3, TG and TC. Analysis was performed using ANOVA and LSD post-hoc test, SPSS 16, at the alpha level of 0.05. Ghrelin concentration paralleled HDL-Ghrelin changes. There was no difference in HDL-Ghrelin between groups. Despite reduction of TC in the training groups, no significant relationship was observed between HDL-Ghrelin and HDL2, HDL3, TG and TC. This study showed that isolated HDL contained Ghrelin. In addition, the 8 weeks endurance training of different durations had no correlation with HDL-Ghrelin and lipid profiles. Further studies to confirm these findings are warranted.