Possible role for growth hormone in suppressing acylated ghrelin and hunger ratings during and after intermittent exercise of different intensities in obese individuals

Body weight is influenced by both food intake and energy expenditure. Acylated ghrelin enhances appetite, and its circulating level is suppressed by Growth Hormone. Data on the acylated ghrelin responses to exercise of different intensities in obese individuals are currently not available. This study examined the effects of an intermittent exercise protocol on acylated ghrelin levels and hunger ratings in obese people. Nine inactive male ran on the treadmill at 0900 with progressive intensities of 50, 60, 70, and 80% of VO[2]max for 10, 10, 5, and 2 min respectively. Blood samples were collected before the exercise at 0845 [-15 min as the resting values], after each workload [10, 23, 31, and 36 min during exercise], and at 30, 60, and 120 min thereafter. The control trial was conducted under identical conditions with the exception of exercise. Compared to the baseline, both acylated ghrelin levels and hunger ratings were suppressed at 70% of VO[2]max during exercise [17.74 vs. 9.80 pmol/L and 4.84 vs. 2.96 unit respectively] and remained significantly lower than the control trial 2 h after the cessation of exercise [13.95 vs. 20.32 pmol/L and 3.33 vs. 6.04 unit, respectively]. Growth Hormone increased during the exercise period and peaked at 80% of VO[2]max. These findings indicate that acylated ghrelin concentrations and hunger ratings are suppressed during exercise and two hours thereafter in obese individuals, and it is possible that Growth Hormone caused the suppression of acylated ghrelin

Effect of eight weeks of resistance training on oxidative stress in diabetic rats

Background: Reactive oxygen species have an important role in the development of diabetes and its complications. The purpose of this study was to investigate the effect of eight weeks of resistance training on oxidative stress in heart of diabetic rats

Material and methods: In an experimental study, 24 Wistar rats divided into two groups, 1. Resistance training [n = 12], and 2. Control group [n = 12]. Induction of diabetes was done by a single intraperitoneal injection of streptozotocin [STZ] at a dose of 50 mg/kg dissolved in phosphate buffer [pH, 4.5]. The training protocol consisted of 1 set of 10 climbing with the weight attached to the base of the tail, three times per week and for 8 weeks. Forty eight hours after last training session, animals were anesthetized blood was taken directly from the heart and then the heart removed and left ventricles were isolated and used for biochemical assessments. All the statistical analysis was done by SPSS software version 16. Level of significance was set at ?<0.05

Results: Resistance training group showed significant decrease in MDA and PC of hearts compared to control group [p=0.02 and p=0.03, respectively]. Total glutathione content of the heart in the resistance training group were significantly higher [p<0.001]. Also, resistance training caused to a significant reduction in blood glucose [p=0.001]. Blood insulin levels were not different between groups, [p=0.931]

Conclusion: Finally, it appears that resistance training may reduce blood glucose and oxidative stress of heart and may increase total glutathione content of the heart. Observed reduction in oxidative stress and increased glutathione content, considering the antioxidant and protective properties of glutathione, suggests that these positive changes caused by resistance training may have protective role against development of cardiovascular complications in diabetes