ABSTRACT
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
ABSTRACT
The liver plays a central role in insulin-like growth factor [IGF] system homeostasis. We examine the protective aerobic training on the IGF system following doxorubicin [DOX] induced hepatotoxicity. In this experimental study 48 Wistar male rats [weighing 257 +/- 28 g] were divided into 6 groups: [1] control+placebo [2] control+DOX 10 mg/kg [3] control+DOX 20 mg/kg [4] training+placebo [5] training+DOX 10 mg/kg [6] training+DOX 20 mg/kg. Hepatotoxicity was induced by DOX [10 and 20 mg/kg]. Rats in the 4, 5 and 6 groups performed treadmill running of 25 to 54 min/day and 15 to 20 m/min, 5 days/wk for 6 weeks. While, DOX 10 mg/kg administration result in an insignificant increase in IGF-1 and IGF-1/IGFBP-3 and an insignificant decrease in IGFBP-3, DOX 20 mg/kg administration caused a significant increase in IGF-1 and IGF-1/IGFBP-3, an insignificant decrease in IGFBP-3, as compared to the group 1. Three weeks of the endurance exercise resulted in a significant decrease of IGF-1 and IGF-1/IGFBP-3 levels, and significant increase in IGFBP-3, as compared to the group 1. Furthermore, after 3 weeks endurance training and DOX treatment with 10 mg/kg an insignificant decrease in IGF-1, an insignificant increase in IGFBP-3 and a significant decrease in IGF-1/IGFBP-3 were detected, in comparison to group 2. DOX hepatotoxicity is dose-dependent, acute administration of DOX 20 mg/kg caused an imbalance in the IGF system and protective aerobic training may improve DOX-induced hepatotoxicity by up-regulation of IGFBP3