One-month of high-intensity exercise did not change the food intake and the hypothalamic arcuate nucleus proopiomelanocortin and neuropeptide Y expression levels in male Wistar rats.

OBJECTIVE: The hypothalamic arcuate nucleus proopiomelanocortin (POMC) and neuropeptide Y (NPY) circuitries are involved in the inhibition and stimulation of the appetite, respectively. The aim of this study was to investigate the effects of one-month lasting high-intensity exercise on the POMC mRNA and NPY mRNA expression in the above-mentioned brain structure and appetite and food intake levels. METHODS: Fourteen male Wistar rats (250±50 g) were used and kept in the well-controlled conditions (22±2 °C, 50±5% humidity, and 12 h dark/light cycle) with food and water ad libitum. The rats were divided into two groups (n=7): 1) control group (C, these rats served as controls) and 2) exercised group (RIE, these rats performed a high-intensity exercise for one month (5 days per week) 40 min daily with speed 35 m/min. The total exercise time was 60 min. The body weight and food intake were recorded continuously during the experiments. RESULTS: The results showed relative mRNA expression of POMC and NPY estimated in the hypothalamic arcuate nucleus. There were no significant differences in the NPY and POMC mRNAs expression levels and food intake between C and RIE groups. CONCLUSIONS: The present data indicate that one-month regular intensive exercise did not alter the levels of NPY and POMC mRNAs expression (as two important factors in the regulation of appetite) in the hypothalamic arcuate nucleus and food intake suggesting that this type of exercise itself is not an appropriate procedure for the body weight reduction.

Various responses of male pituitary-gonadal axis to different intensities of long-term exercise: Role of expression of KNDYrelated genes.

The essential role of regular physical activity has been emphasized for maintaining a healthy life. However, unfortunately, during the last few decades, the lifestyle of people has led to a decrease in physical activity. Research studies have shown that exercise of different intensities is applied on reproductive performance indices, luteinizing hormone (LH) and testosterone (T), with different effects. Nevertheless, the molecular and cellular mechanisms underlying its function are not completely understood. Therefore, this study aimed to evaluate the role of kisspeptin, neurokinin-B and pro-dynorphin (KNDY) gene-expression changes located in the upstream of GnRH neurons in transferring the effects of different long-term exercise intensities on male reproductive axis. Twenty-one adult Wistar rats were randomly divided into control, 6-month regular moderate exercise (RME-6) and 6-month regular intensive exercise (RIE-6). In moderate and intensive exercise groups, rats were treated 5 days a week for 60 min, at 22 and 35 m/min, respectively. Finally, the hypothalamic arcuate nucleus was isolated and the relative gene expression of kisspeptin (Kiss1), neurokinin-B (Nkb), pro-dynorphin (Pdyn) and gonadotropin-releasing hormone (Gnrh) genes were measured by realtime polymerase chain reaction method. The results showed that RIE-6 treatment decreased Gnrh and increased Pdyn mRNA levels in the arcuate nucleus. Furthermore, although RME-6 treatment decreased Nkb and increased Pdyn mRNA levels, the Gnrh mRNAwas not affected. Regarding the Gnrh mRNA levels and serum concentrations of reproductive indices (LH and T), moderate exercise did not impose harmful effects on the hypothalamic-pituitary-gonadal axis than intensive exercise. The different impacts of diverse long-term exercise intensities on the male pituitary-gonadal axis maybe relay by the various changes in hypothalamic Nkb and Pdyn gene expressions.

Effects of short- and long-term regular exercise on reproductive tissue in streptozotocin-induced diabetic male Wistar rats.

OBJECTIVE: Reproductive disorders are one of the complications of diabetes mellitus. Since conflicting results have been obtained from different studies, which examined serum levels of cytokines in patients with diabetes, and considering the fact that the origin of cytokines cannot be accurately determined from their serum changes, attempts were made in the present study to study histological changes and testicular tissue levels of TNF-α and IL-1 in rats treated with exercise. Considering the effects of exercise in reducing blood sugar level and its complications, two types of short-term and long-term regular exercises were also considered to evaluate their effects on male reproductive tissues. METHODS: In this study, 60 male rats with the weight range of 250±50 g were used and were randomly divided into six groups (10 rats each). Healthy groups included sedentary control group, and groups treated with two and eight weeks of exercise. Rats with type 1 diabetes (induced by streptozotocin) included sedentary control group, groups treated with two and eight weeks of exercise (six groups). All groups were evaluated in terms of testicular tissue levels of TNF-α and IL-1 using ELISA and the histometry of spermatogonia, primary spermatocytes, Sertoli cells, epithelial thickness, diameter of veins, and thickness of the seminiferous tubule. RESULTS: Histological changes resulting from diabetes, particularly in the diameter of testicular veins and a number of cells, including Sertoli, highlights the important fact that tissue perfusion in patients with diabetes is especially crucial, in a way that exercise proved useful for tissue structures by offsetting this complication. Measurement of the cytokines IL-1 and TNF-α in the current study showed that perfusion problems are more important in diabetic complications than inflammatory factors. CONCLUSIONS: The main result of this research is recommendation of investigating the tissue of interest for diagnosis of diabetes complications, measuring inflammatory mediators of tissue rather than evaluating their serum concentrations, and focusing on vascular complications as a major complication of diabetes. Furthermore, regular exercise could help improve the function of reproductive organs in healthy groups and prevent diabetes infertility complications to an acceptable degree in diabetic groups.

Hippocampal BDNF content in response to short- and long-term exercise.

The hippocampus is a region in the brain that is crucial for learning and memory. Previous researches proved that brain-derived neurotrophic factor (BDNF) is a probable responsible protein in the learning and memory formation process. BDNF content is thought to be affected by environmental enrichment and physical activity. The purpose of this research was to identify the effect of short- and long-term forced exercise on hippocampal BDNF levels. A total of 30 Wistar rats were randomly divided into three groups (control, short-term exercise and long-term exercise) and treated by treadmill running based on their group. As the treadmill running period finished, the animals were anesthetized. The hippocampus was dissected out immediately and BDNF content of the samples was assessed by ELISA. None of the exercise paradigms did make any significant change on hippocampal BDNF levels. Although exercise was proposed to up-regulate BDNF levels, these results show that the intensity or the duration of running paradigm used in forced exercise protocols here was not enough to affect BDNF levels in the hippocampus significantly.

Effective Phages as Green Antimicrobial Agents Against Antibiotic-Resistant Hospital Escherichia coli.

BACKGROUND: Bacteriophages are viruses that attack bacteria and lead to their lysis in an efficient and highly specific manner. These natural enemies of bacteria were used as therapeutic agents before the advent of antibiotics. Currently, with the rapid spread of multi-drug resistant bacteria, phage therapy can be an effective alternative treatment for antibiotic resistant bacteria. OBJECTIVES: This study evaluated the effectiveness of bacteriophages in removing antibiotic-resistant clinical Escherichia coli strains in vitro and in vivo. PATIENTS AND METHODS: Different samples were taken from bed sore and foot ulcers of patients with diabetes. E. coli strains were isolated and identified by standard methods. The antibiogram was ascertained using the Kirby Bauer disc diffusion method for ten antibiotics. The bacteriophages were isolated from environmental water samples. They were exposed to the host bacteria by the double-layer agar technique (DLA) to observe plaques. Cross reaction of the phages on test E. coli strains was performed to determine broader-spectrum phages. Phage TPR7 was selected for animal trials. Five groups of mice including a control group, bacterial group, phage group, antibiotic therapy group and phage therapy group, were examined. RESULTS: Ten E. coli strains were isolated from hospital samples. They showed high resistance to the used antibiotics. An effective bacteriophage was isolated for each strain. The cross-reaction showed phages which affect more than six E. coli strains. They can be a good choice for clinical therapeutic use. In animal trials the group challenged with phages after being infected showed similar results as the group treated with gentamicin after being infected. In both groups infection was removed after 48 hours. CONCLUSIONS: According to the results, six strains were resistant to six or seven antibiotics and all strains were at least resistant to two antibiotics. However, for each of these resistant bacteria one bacteriophage was isolated from environmental samples, which showed the effectiveness of bacteriophages to remove clinically resistant E. coli strains. Effective phages in vitro showed effective results in vivo as well.

The Effect of Regular Moderate Exercise on miRNA-192 Expression Changes in Kidney of Streptozotocin-Induced Diabetic Male Rats.

PURPOSE: The purpose of this study was to investigate the regular moderate exercise effect on the miR-192 expression changes in kidney of Streptozotocin- induced diabetic rats. METHODS: Forty adult male Wistar rats were divided into four groups of 10, including Sedentary Control group, Healthy 60 days Exercise group, diabetic group and Diabetic 60 days Exercise. Diabetes was induced by injection of 60 mg/kg Streptozotocin and after 48 hour blood glucose levels higher than 250 mg/dl were included to diabetic rats. After 48 hour of induction diabetes, exercise protocol was begun. Animals performed 5 days of consecutive treadmill exercise (60 min/day) with 22 m/min speeds for 60 days. Kidney of the rats has removed and MicroRNA was extracted from kidney using miRCURY(TM) RNA isolation kit. RESULTS: Exercise upregulated miR-192 expression level significantly in the kidney of diabetic rats in comparison to healthy group. There is not any significant change in miR-192 expression in diabetic 60 days exercise compared to control group. CONCLUSION: These results may indicate that exercise can help to prevent the progression of diabetic nephropathy.

Evaluation of brain-derived neurotrophic factor in diabetic rats.

OBJECTIVE: Brain-derived neurotrophic factor (BDNF) is a member of neurotrophins family that plays a pivotal role in memory and learning. Brain-derived neurotrophic factor mediates health benefits of physical activity both in humans and animals. The nerve damage and cognitive impairment in diabetic rats are thought to be the result of reduced BDNF levels. The purpose of this study was to examine the effect of short- and long-term moderate forced exercise on BDNF levels in the hippocampus of type 1 diabetic rats. METHODS: A total of 40 male Wistar rats have been divided into four groups [control group, sedentary diabetic (SD) group, diabetic group with 2 week exercise, and diabetic group with 8 week exercise]. Exercised groups were treated with moderate treadmill running for 60 minutes per day on a rat treadmill. The animals were tested in a Morris water maze (MWM) for spatial memory and the BDNF levels in the hippocampus were assessed by ELISA kit. RESULTS: The Spatial memory test showed a significant improvement in exercised groups in comparison to sedentary groups. Based on the running protocol no significant difference was found on BDNF levels between groups. DISCUSSION: It was shown that spatial memory was improved by the exercise protocol, while the BDNF levels did not change significantly in any group. As a BDNF secretion in the brain is dependent on running paradigm factor, the protocol chosen might not be intensive or long enough to increase the BDNF levels. Exercise may improve spatial memory in type 1 diabetic rats in a way that BDNF is not included.

The effects of aerobic exercise training on the age-related lipid peroxidation, Schwann cell apoptosis and ultrastructural changes in the sciatic nerve of rats.

The potential role of exercise in preventing the age-related spontaneous peripheral neuropathy has not been studied. We examined the effects of long-term aerobic exercise training on lipid peroxidation, Schwann cell (SC) apoptosis and ultrastructural changes in the sciatic nerve of rats during aging. Three groups of 12-week old Wistar rats ran on a treadmill for 6, 9 and 12 months (exercise trained (ET) group, n=10 each) according to an exercise training program targeted at a speed of 22 m/min (at 7 degrees incline), 60 min/day, 6 days/week. Three corresponding groups of untrained rats were used as the controls (sedentary (SED) group). At the end of each period, sciatic nerve biopsies were performed, and processed for biochemical, immunohistochemical and ultrastructural analyses. The results showed that aging was associated with an increased level of nerve malondialdehyde (MDA, marker of lipid peroxidation) and a higher number of SC apoptosis in SED group. The SED group showed irregular nerve fibers with thin myelin sheaths and areas of myelin-axon detachment. However, the ET group had significantly diminished nerve lipid peroxidation and SC apoptosis. In the ET group, nerve fibers had a thick myelin sheath with frequent folding. These findings suggest that aerobic exercise training protects peripheral nerves by attenuating oxidative reactions, and preserving SCs and myelin sheath from pathologic changes, which occur during normal aging.

Long-term exercise training affects age-induced changes in HSP70 and apoptosis in rat heart.

The aim of this study was to test the effects of age and long-term exercise training on antioxidant, heat shock protein 70 (HSP70) expression and apoptosis by comparing the hearts of sedentary and trained rats. Training groups went under 3-, 6- and 9-months of regular exercise (25 m/min with a 0% slope, 60 min/day and 6 days/week). Level of glutathione increased with age in trained and sedentary control rats but level of this factor unchanged by training. Activity of mitochondrial superoxide dismutase (mtSOD) increased in heart homogenates of 6- and 9-months trained animals as compared with their sedentary. The rates of apoptosis were increased with age but level of apoptosis in 9-months trained group was significantly lower than corresponding sedentary. Levels of HSP70 expression were significantly decreased with age while long-term training induced marked increase in HSP70 expression levels. These results show that a long-term regular exercise affects age-induced changes in mtSOD, HSP70 and apoptosis as it increases mtSOD activities and HSP70 expression levels and elicits a marked reduction in apoptosis rate in rat myocardium. However, a shorter training program is not effective.

Effects of age increment and 36-week exercise training on antioxidant enzymes and apoptosis in rat heart tissue.

This study investigated the onset of age-related changes in the myocardial antioxidant enzymes and apoptosis and the vulnerability of the myocardium to oxidative stress following exercise training. Few studies have investigated the influence of the most prevalent life-prolonging strategy physical exercise, on the age increment alterations in the myocardial antioxidant enzymes and apoptosis at mid age and to determine whether exercise-induced antioxidant defense system could attenuate lipid peroxidation. Thirty six male Wistar rats were randomly assigned to exercise trained (n = 18) and sedentary (n = 18) groups. The rats in the training group went under 12, 24 and 36 weeks of moderate exercise trainings (25 m·min(-1) for 60-min with a 0% slope). Six sedentary controls were killed together with each exercise group at the end of the training programs. Levels of thiobarbituric acid-reactive substances (TBARS) and catalase (CAT) activity in myocardial homogenates were unchanged by training irrespective of the protocol duration. However, an increased content of the TBARS was detected in hearts from both the 24 and 36-week trained and sedentary control rats when compared with their corresponding 12-week groups (p<0.01). The activity of superoxide dismutase (SOD) remained unchanged after the 12-week training period whereas a significant increase was observed in heart homogenates of 24-week trained animals as compared with their sedentary controls (p<0.05). The activity of glutathione peroxidase (GPX) remained unchanged. The rates of apoptosis which was detected by ELISA assays, were significantly modified after 24 and 36-week of training (p<0.05). These results demonstrate that a long-term endurance training (24 weeks) induced increases in SOD activities in rat myocardium and elicited a marked reduction in apoptosis rate. However, a shorter training program (12 weeks) was not effective in increasing heart antioxidant defenses. Key pointsExercise training induces activity of myocardial SOD.Long-term regular moderate-intensity exercise decreases the rate of myocardial apoptosis.Short-term regular moderate-intensity exercises do not change the rate of myocardial anti oxidant capacity and apoptosis.