[ effects of endurance training and whey protein supplementation on inflammation and insulin resistance in the rats fed with high-fat diet]

Background and Aim: Whey protein has been known to be an excellent prophylactic agent against obesity. The aim of this study was to assess the effect of endurance training and whey protein supplementation on TNF-alpha levels and insulin resistance in the rats fed with high-fat diet

Materials and Methods: In the first phase of the study, 40 male Wistar rats were randomly assigned to two groups: one group was fed with standard chow [n = 8] and the other group with high fat diet [HFD] [n = 32]. After 9 weeks, in the second phase of our study, HFD rats were randomly assigned to 4 groups: [1] control, [2] whey supplementation, [3] endurance training and [4] endurance training + whey supplementation groups. Each group consisted of 8 rats. Endurance training protocol was performed for 10 weeks [5days/wk, Ihr/day, 21m/min, and 15% grade]. Data were analyzed by Mann-Whitney U test [to compare normal control group and control high-fat diet group] and two way ANOVA

Results: Body weight [P=0.009], adipose tissue [P=0.002], insulin resistance [P=0.045] and TNF-a level [P=0.022] were significantly higher in HFD sedentary rats, compared to those in the rats in normal diet control group. Adipose tissue weight [P=0.02], blood glucose [P=0.006], insulin [P=0.0003], insulin resistance index [P=0.00021] and TNF-alpha level in adipose tissue [P=0.039] in whey supplemented groups were lower than those in the non-supplemented groups. Also, body weight [P=0.017], adipose tissue weight [P=0.001] adipose tissue TNF-alpha level [P=0.001] in the training groups were lower than those in the control group

Conclusion: Whey protein supplementation led to improvement of high-fat diet-induced insulin resistance and decreased inflammation. Endurance training also reduced inflammation in adipose tissue

[Effects of four week progressive resistance training on plasma FABP4 and lipid profile concentrations in diabetic rats]

FABP4 [A-FABP or aP2] is a member of the fatty acid-binding protein family that plays an essential regulatory role in energy metabolism and inflammation. The aim of this study was to investigate the effect of resistance training with progressive load on plasma levels of FABP4 and the lipid profile in Streptozotocin-induced diabetic rats. Twenty four male Wister rats [12-14 weeks old] were randomly divided into three groups: Non-diabetic control, diabetic control, and diabetic training. Rats in the diabetic training group were subjected to a resistance training program [3 days/wk, for 4 wk], which consisted of climbing a ladder while carrying a load suspended from the tail. Plasma levels of glucose, FABP4 and lipid profiles, as well as liver cholesterol and triglycerides were measured. Plasma FABP4 concentration in the diabetic control group was significantly lower compared with non-diabetic controls and diabetic training groups respectively, [P=0.016 and P<0.001]. We did not find any significant difference in plasma lipid profiles between the groups. The amount of liver triglycerides in the diabetic training group was significantly lower compared with the non-diabetic control group [P=0.020]. Results indicated that 4 weeks resistance training decreases liver triglycerides, and increases plasma FABP4 concentrations in streptozotocin induced diabetic rats. Further research is needed to elucidate the physiological significance of circulating FABP4 levels

[Obestatin and the regulation of energy balance in physical activity]

Obestatin, a peptide which is encoded by the same preproghrelin gene as Ghrelin, conveys information concerning the nutritional status and/or the energy stores to the central nervous system. In obese populations, circulating levels of the peptide are altered. Ghrelin, mostly acting through the GH secretagogue receptor GHS-R, is a potent GH secretagogue, an orexigenic peptide and a long-term regulator of energy homeostasis. Obestatin was described for its anorexigenic effects and it's binding to GPR39. However recent studies do not support the role of obestatin/GPR39 system in the regulation of energy balance. Because exercise training improves the health status of obese individuals and is associated with reduction of body weight, there is growing interest in the effects of exercise on obestatin and whether this peptide may provide better understanding of how exercise improves health. Obestatin levels do not increase in response to acute exercise, and therefore obestatin does not appear to regulate growth hormone [GH] release during exercise. There is some evidence that obestatin levels do not change in plasma following resistance exercise with higher GH concentrations during exercise and decreases in tissues following chronic exercise but not in plasma. This review is focuses on obestatin, by first summarizing it function and it relationship with hormonal and metabolic changes that affect energy balance, and then discussing the effects of acute and chronic exercise on plasma and tissues obestatin concentrations, and the potential mechanisms involved

[Effects of circuit resistance training on plasma ghrelin levels in young women]

Ghrelin, an orexigenic peptide secreted from stomach mucosa, affects feeding behavior and plays an important role in energy balance and glucose homeostasis. Ample evidence indicates that resistance exercise is a key component of exercise recommendations for weight control. The purpose of the current study was to determine the effects of resistance training [4 weeks] on resting levels of plasma ghrelin, glucose, insulin and estrogen. Twenty-seven female college students, aged 221 +/- 1.54 years, height 162.66 +/- 5.05 cm, BMI 20.76 +/- 1.86 kg/m[2] and fat percent 20.95 +/- 2.08% [means +/- SE] were randomized into two, the experimental [40% and 80% 1RM] and the control groups. Subjects performed circuit-resistance exercise protocol with 40% and 80% 1RM, 4 d/wk for 4 weeks. Blood samples were collected 24 hours before and 48 hours after the training program. One-way ANOVA revealed that although no significant differences were observed in circulating levels of plasma total ghrelin [P=0.88], glucose [P=0.1] and insulin [P=0.66] in the experimental group when compared to the control group, a significant negative correlation [R=-0.4, P=0.05] was found between plasma estrogen and total ghrelin levels. It seems that because of a non significant increase in plasma ghrelin levels in the present study, there was no weight change of subjects during the training program and the short duration of the training program. However, the total ghrelin sub-fractions, acylated and non acylated, may have changed

[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 HDLGhrelin 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

Effect of 8 weeks endurance training with two different durations on plasma HDL and ghrelin in male rats

Nesfatin-1, a novel anorexigenic protein derived from the Nucleobindin-2 [NUCB2] gene, is expressed in adipose tissue and is found in plasma. The purpose of this study was to examine the effect of an eight-week endurance training regimen on nesfatin gene expression and its concentration in the male rat liver. Eleven adult Wistar male rats were used. Animals were randomly divided into the training [TS, n=6] and control [CS, n=5] groups. Training groups were given exercise on a motor-driven treadmill [0% grade, 60 min, and 5 days/week for 8 weeks, 50-55%VO2max]. Samples of liver were excised and stored in liquid nitrogen to extract nesfatin-1 mRNA, and to determine its concentration and that of glycogen by RT-PCR, ELISA and colorimetric assay respectively. Although liver nesfatin mRNA expression and its concentration were increased, changes were not significant. Also liver glycogen concentration was significantly higher in trained rats compared to controls. The results of this research showed for the first time that nesfatin-1 is first expressed in the liver as a peripheral tissue and it then changes with endurance training. The insignificant variations of nesfatin-1 in the liver might be attributed to its role in energy balance. It seems that relative improvement in the liver's energy status is influenced by nesfatin gene expression, whereas as an indicator of source ATP, was lower in trained group compared to control group

effect of a single session aerobic exercise on plasma ghrelin, GH, insulin and cortisol in non-athlete university male students

Ghrelin, a peptide hormone secreted from the endocrine cells of stomach, affects appetite, energy consumption, weight, and body composition. Although the effects of endurance exercise on weight loss have been demonstrated, results on the impact of this exercise on ghrelin levels are controversial, and are from studies performed in athletes. The aim of this study was to investigate the response of serum ghrelin, growth hormone, and cortisol after a single session of aerobic exercise in young non-athlete male students. Sixteen non-athlete male students, randomly selected, performed a single session of aerobic exercise, including 3 consecutive- one mile running sessions with 3 minutes rest period at the end of each mile. The participants in this study had a mean age 22.1 +/- 2A years, weight 72.8 +/- 5.7 kg, height 177.915.7 cm, and body mass index 23.2 +/- 1.7. To determine levels of these hormones, plasma ghrelin, GH, insulin, and cortisol, blood samples were taken, using the ELISA method. The results of paired-samples t-test showed that the levels of growth hormone and ghrelin increased significantly in the plasma, whereas insulin and cortisol levels decreased [P<0.05]. These data suggest that a single session of aerobic exercise can decrease energy reservoirs and increase ghrelin secretion in response to energy deficit to supply and balance the sources of energy loss. Therefore it is clear that activity duration is an important parameter in the increase in ghrelin levels in response to exercise

Effects of treadmill exercise on fundus ghrelin expression and plasma acylated ghrelin level in male rats

The gastric peptide ghrelin, an endogenous ligand for growth-hormone secretagogue receptor, in its acylated form induces a positive energy balance, increase in food intake and adiposity. This study aimed at determining the effects of treadmill exercise training on fundus Ghrelin mRNA expression, fundus, and plasma acylated Ghrelin concentration in rats. Thirty-six adult Wistar male rats [12-14 weeks old, 200-220g] were randomly divided into the experimental 1 [EX1] [n=16] and experimental 2 [EX2, n=20] groups with further division into control [n=8 and 10] and training [n=8 and 10] groups. Training groups were given exercise on a motor-driven treadmill [28 m/min, 0% grade, 60 min, 5 days/week for 8 weeks]. Rats in EX1 were further divided into four groups; fed-control [FEC], fed-trained [FET], fast-control [FAT] and fast-trained [FAT]. Twenty-four hours after last training session, the fundus was excised and frozen in liquid nitrogen for extraction of ghrelin mRNA. Fundus and plasma acylated ghrelin, growth hormone [GH], insulin, cortisol, lipids, and glucose were also measured. Ghrelin mRNA expression was significantly [P=0.002] higher in fasted rats and lower in trained-rats, in whom a non significant increase was observed in resting plasma acylated Ghrelin, GH, insulin, liver glycogen and lower free fatty acids concentrations and muscle glycogen. Plasma cortisol, triglycerides [TG], total cholesterol [TC] was remained unchanged. Interestingly, fundus acylated ghrelin was significantly [P=0.031] lower in trained rats. The data obtained showed that treadmill exercise reduced ghrelin expression and its acylated levels in the fundus of trained rats and a higher plasma acylated ghrelin could be released from other source [s]

effect of exercise on plasma acylated ghrelin concentrations and gastrocnemius muscle mRNA expression in male rats

Ghrelin is a gut hormone predominantly produced by the stomach and, to a lesser extent, by other regions of the gastrointestinal tract. Ghrelin circulates in the bloodstream in two different forms: acylated [or n-octanoylated] and unacylated [or des-octanoylated or des-acylated]. The purpose of this study was to examine the effect of 12 weeks training on plasma acylated ghrelin concentrations and gastrocnemius muscle mRNA expression in male rats. Twenty adult Wistar male rats [8 weeks old, 280 +/- 20 g] were used. Animals were randomly divided into experimental [EX, n = 10, V=34m/min]

effect of treadmill running on plasma and muscle agouti-related protein [AGRP] concentration in male rats

Appetite regulation is one of the most important issues in exercise physiology. AGRP is one of the most important neuropeptide in appetite regulation and energy homeostasis. The aim of this study was to investigate the effect of treadmill running on plasma and muscle [Soleus] concentration of AGRP in male Wistar rats. Forty rats were randomly assigned into two groups. The training group was given exercise on a motor-driven treadmill at 28 m/min [equal to 75% vo2max] for 60 min/day, 5 days/week for 10 weeks. After finishing the exercise protocol, each group was divided into 2 subgroups, the fasting and the fed [n=10] groups. Each subgroup was anesthetized and sacrificed after an overnight fast and the other, after 3 hours of food deprivation. The results showed muscle and plasma AGRP were significantly [P < 0.001] higher in the trained rats in comparison to the control rats. Also there was a significant and positive correlation between Soleus AGRP and plasma AGRP. It can be speculated that negative energy balance as well as local hyperphagia in muscle, induced by exercise produces satiety, signals the hypothalamus, which therefore increases release of AGRP facilitating energy recovery. This mechanism may be involved in glycogen supercompensation as well

[Effects of exercise training on high molecular weight adiponectin in healthy male rat]

The high-molecular weight [HMW] from of adiponectin is reported to be the most active from of this hormone and current data reveals decreased plasma HMW adiponectin levels to be associated with insulin resistance. This study was intended to investigate the effect of exercise intensity on plasma HMW adiponectin concentrations. Thirty-two eight week-old male Wistar rats [185 +/- 50 g] were randomly assigned to one of four groups as follows: High intensity [HI: 34 m/min %80 -%85 VO2 max] moderate intensity [MI: 23m/min%70-%75 VO2 max], Low intensity [LI: 20m/min%50-%55 VO2 max], and the sedentary control [SED] groups. All experimental groups performed a 12 week exercise program, including treadmill running on a 0° slope for 1 hr/day, 5 days/week. Fasting levels of circulating HMW adiponectin, testosterone, and insulin resistane index [HOMA-IR] were measured after the exercise program and, data were analyzed using one-way ANOVA, with Pearson's correlation was used to identify any possible relationship among the assessed variables. HMW adiponectin plasma concentrations increased significantly in the HI and MI exercise training groups [p<0.05]. HMW adiponectin was also found to be inversely related to HOMA-IR [r = -0.37, p= 0.003], insulin [r= -0.46, p= 0.008] and testosterone [r= -0.38, p= 0.03]. It can be conclude that exercise intensity appears to be an important parameter in increasing plasma HMW adiponectin levels in healthy male rats

Investigating the effect of laser assisted hatching on the development and quality of vitrified-warmed 4-celI stage mouse embryos

The aim of this study was to investigate the effect of laser assisted hatching on the development and quality of vitrified-warmed 4-cell stage mouse embryos. The vitrified-warmed 4-cell mouse embryos were divided into two groups: control group [without laser assisted hatching] and experiment group [with laser assisted hatching]. All embryos in both groups were cultured in sequential media containing G1TMver3 and G2TMver3. Afterward, all expanded blastocysts were randomly selected and stained with differential [for cellularity] and TUNEL [for cell death] methods. On day 1[24hrs] of culture, the difference between the control and the experimental groups was insignificant in the rate of blastocyst formation. But on day 2[48hrs] of culture, 87.61% of embryos in the experimental group reached the blastocyst stage. This rate did not increase significantly as compared to the control group [78.14%]. Finally on day 3 [72 hrs], the rate of blastocyst formation reached 94.40% and 81.75%, respectively, in both the experimental and control groups. The difference between these two groups were significant [p<0.05]. The number of blastomeres and apoptotic cells were similar in the experimental and control groups. The laser assisted hatching has no decreasing effect on cellularity, but it has increasing effect on incidence of cell death. In addition, the assisted hatching significantly increases the blastocyst formation rate of intact vitrified-warmed 4-cell stage mouse embryos