Effect Of Moderate Treadmill Exercise Research Articles

Moderate Treadmill Exercise Modulates Gut Microbiota and Improves Intestinal Barrier in High-Fat-Diet-Induced Obese Mice via the AMPK/CDX2 Signaling Pathway.

ObjectiveThe aim of this study was to investigate the effects of moderate treadmill exercise on gut microbiota, expression of proteins associated with gut barrier and to elucidate the mechanisms underlying their role in high-fat-diet-induced obese mice.MethodsSix-week-old male C57BL/6 mice were randomly divided into standard chow diet control group (SD + Sed, n=6), chow diet exercise group (SD + Exe, n=6), high-fat diet control group (HFD + Sed, n=6) and high-fat diet exercise group (HFD + Exe, n=6). Exercise groups were trained on a motorized treadmill for 45 min/d at running speeds of 12 m/min, 5 days/week, for 12 consecutive weeks. The body weight and fasting blood glucose of the mice were recorded before euthanasia. Thereafter, the mice were sacrificed and the alteration of adipose mass, colonic histopathology, gut microbiome and gut barrier-related molecules were tested.ResultsIt was found that the moderate treadmill exercise prevented the development of adiposity and hyperglycemia and effectively improved the loss of diversity and the relative abundance of intestinal microflora induced by high-fat diet. Moreover, regular exercise reversed the intestinal pathology and elevated the number of goblet cells in obesity. Besides, compared with the sedentary obese mice, the protein expression levels of colonic ZO-1 and occludin were enhanced and AMPK/CDX2 signaling pathway was significantly upregulated in obese mice that underwent exercise.ConclusionLong-term moderate treadmill exercise can markedly reduce the degree of obesity, modulate the colonic gut microbiota, and effectively activating AMPK/CDX2 signaling pathway to improve intestinal barrier in obese mice induced by high-fat diet.

Physical exercise prevents amyloid β1-40-induced disturbances in NLRP3 inflammasome pathway in the hippocampus of mice.

Amyloid beta (Aβ), one of the main hallmarks of Alzheimer's Disease (AD), may stimulate pattern recognition receptors (PRR) such as the NLRP3 inflammasome, inducing a pro-inflammatory state in the brain that contributes to disease development. Physical exercise can have multiple beneficial effects on brain function, including anti-inflammatory and neuroprotective roles. The objective of this study was to investigate the prophylactic effect of moderate treadmill exercise for 4 weeks on inflammatory events related to NLRP3 signaling in the hippocampus of mice after intracerebroventricular Aβ1-40 administration. Our results show that Aβ1-40 administration (400pmol/mouse, i.c.v.) significantly increased the immunocontent Iba-1 (a microglial reactivity marker), NLRP3, TXNIP, and caspase-1 in the hippocampus of mice. However, physical exercise prevented the hippocampal increase in Iba-1, TXNIP, and activation of the NLRP3 inflammasome pathway caused by Aβ1-40. Moreover, physical exercise per se reduced the TXNIP and caspase-1 immunocontent in the hippocampus. No alterations were observed on the immunocontent of GFAP, ASC, and IL-1β in the hippocampus after Aβ1-40 and/or physical exercise. These results reinforce the role of NLRP3 inflammasome pathway in AD and point to physical exercise as a possible non-pharmacological strategy to prevent inflammatory events triggered by Aβ1-40 in mice.

Treadmill exercise ameliorates memory deficits and hippocampal inflammation in ovalbumin-sensitized juvenile rats

The behavioral changes, including spatial learning and memory impairment as well as depressive- and anxiety-like behaviors in an animal model of asthma were demonstrated previously. On the other hand, there is increasing evidence that the anti-inflammatory actions of exercise are related to their neuroprotective properties against different insults in the brain. This study was aimed to explore the effects of moderate treadmill exercise on cognitive deficits and possible anti-inflammatory mechanisms in ovalbumin (OVA)-sensitized rats. The exercise groups were trained to run on the treadmill 30 min/day with an intensity of 12 m/min, 5 days/week for 4 weeks. Animals in the OVA groups were sensitized by two intraperitoneal (i.p.) injections of OVA (10 μg/injection) and challenged with OVA by inhalation during the treadmill running exercise period. Passive avoidance (PA) memory, levels of interleukin (IL)-10 and tumor necrosis factor (TNF)-α in the hippocampus, total and differential white blood cell (WBC) count in the blood as well as pathological changes of the lung were then evaluated. OVA-sensitization was resulted in cognitive deficits in the PA task, along with increased total and differential WBC in blood and TNF-α in the hippocampus. However, exercise ameliorated these changes and increased the IL-10 level in the hippocampus, suggesting that moderate treadmill exercise can improve memory impairment in OVA-sensitized rats due to its anti-inflammatory properties.

Effect of Moderate Treadmill Exercise on Hepatic Lipid Metabolism in Rats

Several and complex factors cause accumulation of large amounts of body fat as well as a disparity between energy intake and output. Generally, any increase in bodyweight can be attributed to the elevation in daily food intake and the reduction in energy expenditure. Several functions could be achieved by moderate exercise including maintaining an optimum body weight and muscle mass, lowering abdominal fat and increasing lipid catabolism. However, the exact molecular mechanisms involved remain understudied. Our study was designed mainly to evaluate the influence of moderate treadmill exercise on body metabolism with special reference to hepatic lipid metabolism. Twenty adult male Sprague Dawley rats weighting 200±20 gm were randomly assigned to either sedentary or exercised groups. The exercise protocol lasted for 20 mins/ 5 times / week along 4 weeks. Although no significant changes in body weight, insulin and corticosterone levels, there was a significant decrease in fasting blood glucose and serum leptin levels (81.06%and 75.49% respectively). The current exercise regime significantly increased serum high density lipoprotein (HDL-c) level (127.56%) and significantly decreased serum triacylglycerol (TAG), low density lipoprotein (LDL-c) and very low-density lipoprotein (VLDL-c) levels (75.50%, 62.83% and 74.48% respectively). Also, treadmill exercise significantly upregulated the hepatic expression of acetyl-CoA oxidase (ACO) and carnitine palmitoyl CoA transferase 1 (CPT1) (173% and 148% respectively) as well as significantly downregulated the hepatic acetyl-CoA carboxylase (ACC) (52%) but not fatty acid synthase (FAS) mRNA expression. Overall, these results suggest a beneficial effect of moderate treadmill exercise hepatic lipid metabolism.

Reproprotective Effects of Moderate Exercise in Male Rats Doped with Testosterone Enanthate

A total of forty adult Sprague-Dawley male rats were used to study the ameliorative effects of moderate exercise on reproductive function in male rats doped with a high dose of anabolic steroids. Rats were randomly assigned into 4 groups; sedentary, sedentary doped (I/M 25 mg/kg BW per week), moderately exercised (20 minutes/day for five days every week along one month) and moderately exercised doped groups. The results clarified that the moderate exercise significantly increased sperm motility (91.67%±1.67); live sperm and sperm count percentages (93.33%±1.67 & 115.33%±7.51 respectively) and lowered sperm abnormalities (11.0±3.61). On contrary, doping induced via testosterone administrations in both sedentary and moderately exercised rats significantly decreased the previously mentioned sperm parameters (63.33%±3.33, 53.33%±3.33 & 65.33%±9.45 respectively) while increasing sperm abnormalities (53.33±11.50); although amelioration via exercise was noticed in these parameters. Serum free testosterone levels were significantly increased with both sedentary doped or moderately exercised doped groups. Moreover, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities were significantly elevated with moderate exercise (52.05±6.67, 39.25±7.09 and 69.17±7.69 respectively). While, malondialdehyde (MDA) levels were increased with doping of male rats (86.5±9.99). Furthermore, StAr gene expression was significantly (P≤0.01) up-regulated with moderate exercise and significantly (P≤0.01) down-regulated with doping of male rats. In addition, HSD17B3 gene expression was significantly (P≤0.01) up-regulated in both moderately exercise and moderately exercise doped groups. On contrary, HSD17B3 gene expression was significantly (P≤0.01) down-regulated in sedentary doped group Overall, these results suggest a beneficial and protective effect of moderate treadmill exercise on male fertility especially in steroid abuse models.

Anxiolytic-like effects of treadmill exercise on an animal model of post-traumatic stress disorder and its mechanism.

Many studies have proven the beneficial effects of regular exercise on psychiatric conditions. This study was set to explore the therapeutic effects and the mechanisms of treadmill exercise on a time-dependent sensitization (TDS) model which is a classical animal model for mimicking posttraumatic stress disorder (PTSD). Forty-seven rats were randomly assigned to one of four groups: CON (control), TDS (model), EX (treadmill), or SER (sertraline). TDS model was developed to evaluate the anti-PTSD-like effects of moderate treadmill exercise with 4-week running program. High-performance liquid chromatography technology was used to determine the levels of monoamine neurotransmitters in TDS rats. The expression of key proteins in BDNF/PI3K/Akt/CREB signaling pathway were assayed by the Western blot method. The TDS procedures induced behavioral deficiencies. These deficiencies were reversed by treadmill exercise. Subsequent monoamine assays revealed that the treadmill exercise significantly increased serotonin levels in the hippocampus and decreased dopamine levels in the prefrontal cortex. Data from Western blot experiment demonstrated that exercise could normalize the decreased BDNF/TrkB/pAkt/pCREB levels in the hippocampus. This study deduced that treadmill exercise ameliorated contextual fear conditioning and anxiety-like behavior in TDS model. According to the study, the mechanism involved in alleviating PTSD symptoms by treadmill exercise was due to increased 5-HT levels in the hippocampus and decreased DA levels in the prefrontal cortex. It also involved the upregulation of BDNF and the related PI3K/AKT/CREB signaling pathway.

The effect of moderate treadmill exercise on the resistive index of the medial long posterior ciliary artery in dogs

The resistive index (RI) is an indirect measurement of arterial resistance by means of a ratio between the peak systolic and end diastolic velocities recorded with a spectral Doppler device, especially used to evaluate the vascular damage in ocular diseases such as glaucoma. Some ocular variables such as the intraocular pressure (IOP), the choroidal thickness, the axial length and the ocular blood flow may be influenced by physical exercise. The purpose of this study was to evaluate the influence of the exercise on the RI of the medial long posterior ciliary artery in dogs, and correlate the data obtained with the IOP values. Ten clinically healthy dogs were subjected to moderate physical exercise on a canine motorised treadmill at different speeds for 45 minutes. A colour Doppler examination was performed and the RI values were calculated for the medial long posterior ciliary artery at rest, immediately after the exercise, and after 60 minutes at the end of the exercise. At the same times, the IOP was recorded by applanation tonometry. The data were analysed by a two-way repeated ANOVA measurement in order to compare the RI and the IOP. Wilcoxon’s test was applied for the post hoc comparison. Spearman’s rank correlation for non-normal distribution was used to determine a relationship between the RI and the IOP. The at rest RI was 0.722 +/–0.022, IOP 12.38 +/3.21 mm Hg. A significant decrease in the RI was observed immediately after the exercise (0.697 +/–0.035) and during the passive recovery phase (0.682 +/–0.042). A significant decrease in the IOP (11+/3.39 mmHg) was recorded after 60 min of the passive recovery phase; at the end of the exercise, a slight decrease (12.29+/4.26 mm Hg) mm Hg was detected. During the test, a linear correlation between the RI and the IOP was observed. Our results suggest that exercise induces the modification of the ophthalmic blood flow in dogs, presumably related to the compensatory neuro-hormonal mechanisms.

Bipolar disorder may increase the risk of caesarean section

The behavioral changes, including spatial learning and memory impairment as well as depressive- and anxiety-like behaviors in an animal model of asthma were demonstrated previously. On the other hand, there is increasing evidence that the anti-inflammatory actions of exercise are related to their neuroprotective properties against different insults in the brain. This study was aimed to explore the effects of moderate treadmill exercise on cognitive deficits and possible anti-inflammatory mechanisms in ovalbumin (OVA)-sensitized rats. The exercise groups were trained to run on the treadmill 30 min/day with an intensity of 12 m/min, 5 days/week for 4 weeks. Animals in the OVA groups were sensitized by two intraperitoneal (i.p.) injections of OVA (10 μg/injection) and challenged with OVA by inhalation during the treadmill running exercise period. Passive avoidance (PA) memory, levels of interleukin (IL)-10 and tumor necrosis factor (TNF)-α in the hippocampus, total and differential white blood cell (WBC) count in the blood as well as pathological changes of the lung were then evaluated. OVA-sensitization was resulted in cognitive deficits in the PA task, along with increased total and differential WBC in blood and TNF-α in the hippocampus. However, exercise ameliorated these changes and increased the IL-10 level in the hippocampus, suggesting that moderate treadmill exercise can improve memory impairment in OVA-sensitized rats due to its anti-inflammatory properties.

Moderate treadmill exercise ameliorates amyloid-β-induced learning and memory impairment, possibly via increasing AMPK activity and up-regulation of the PGC-1α/FNDC5/BDNF pathway

Alzheimer’s disease (AD) is a neurodegenerative disorder associated with loss of memory and cognitive abilities. Previous evidence suggested that exercise ameliorates learning and memory deficits by increasing brain derived neurotrophic factor (BDNF) and activating downstream pathways in AD animal models. However, upstream pathways related to increase BDNF induced by exercise in AD animal models are not well known. We investigated the effects of moderate treadmill exercise on Aβ-induced learning and memory impairment as well as the upstream pathway responsible for increasing hippocampal BDNF in an animal model of AD. Animals were divided into five groups: Intact, Sham, Aβ1−42, Sham-exercise (Sham-exe) and Aβ1−42-exercise (Aβ-exe). Aβ was microinjected into the CA1 area of the hippocampus and then animals in the exercise groups were subjected to moderate treadmill exercise (for 4 weeks with 5 sessions per week) 7 days after microinjection. In the present study the Morris water maze (MWM) test was used to assess spatial learning and memory. Hippocampal mRNA levels of BDNF, peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α), fibronectin type III domain-containing 5 (FNDC5) as well as protein levels of AMPK-activated protein kinase (AMPK), PGC-1α, BDNF, phosphorylation of AMPK were measured. Our results showed that intra-hippocampal injection of Aβ1−42 impaired spatial learning and memory which was accompanied by reduced AMPK activity (p-AMPK/total-AMPK ratio) and suppression of the PGC-1α/FNDC5/BDNF pathway in the hippocampus of rats. In contrast, moderate treadmill exercise ameliorated the Aβ1−42-induced spatial learning and memory deficit, which was accompanied by restored AMPK activity and PGC-1α/FNDC5/BDNF levels. Our results suggest that the increased AMPK activity and up-regulation of the PGC-1α/FNDC5/BDNF pathway by exercise are likely involved in mediating the beneficial effects of exercise on Aβ-induced learning and memory impairment.

Effect of Moderate Treadmill Exercise on hip Osteoarthritis in Male and Female Wistar Rats

Background: Osteoarthritis (OA) is a slowly progressive degenerative disease characterized by gradual loss of articular cartilage. The influence of excessive running load on the development of knee OA was investigated in male Wistar rats. This study was done to test the sex-related difference in the risk of OA of the hip joint after moderate running exercise. M aterials and Methods: Forty male and female Wistar rats were randomly assigned to four equal groups (2 male and 2 female groups) in a same condition. Ten of each sex were selected as control groups and kept separately while running exercises were performed in remained 20 male and female rats using a motor treadmill to motivate rats to run daily distances of 1 km at 5 days/week within six weeks. The treadmill incline was zero. On day 43, all control and training animals were killed and the hip articular cartilage and its synovial layer were evaluated microscopically. R es ults: The appearance of hip articular cartilage was normal and similar in all male, female and also male running groups while female running group showed some changes. Obtained results showed a mild OA only in the female running group. There wasn’t seen synovitis in both male and female running groups in comparison with control groups (P>0.05). Conclusion: This study showed that the development of hip OA may be related to the sex differences as seen in the knee OA previously.

Effects of moderate treadmill exercise and fluoxetine on behavioural and cognitive deficits, hypothalamic-pituitary-adrenal axis dysfunction and alternations in hippocampal BDNF and mRNA expression of apoptosis – related proteins in a rat model of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a condition that develops after an individual has experienced a major trauma. Currently, selective serotonin reuptake inhibitors (SSRIs) like fluoxetine are the first-line choice in PTSD drug treatment but their moderate response rates and side effects indicate an urgent need for the development of new treatment. Physical activity is known to improve symptoms of certain neuropsychiatric disorders. The present study investigated the effects of moderate treadmill exercise, the antidepressant fluoxetine and the combined treatment on behavioural deficits, and hypothalamic-pituitary-adrenal (HPA) axis dysfunction. We also examined alternations in hippocampal brain-derived neurotrophic factor (BDNF) and mRNA expression of apoptosis - related proteins in a rat model of PTSD: the single prolonged stress (SPS) model. Rats were exposed to SPS (restraint for 2h, forced swimming for 20min and ether anaesthesia) and were then kept undisturbed for 14days. After that, SPS rats were subjected to chronic treatment with fluoxetine (10mg/kg/day, for 4weeks), moderate treadmill running (4weeks, 5day per week) and the combined treatment (fluoxetine plus treadmill exercise), followed by behavioural, biochemical and apoptosis markers assessments. SPS rats exhibited increased anxiety levels in the elevated plus maze and light/dark box, impaired fear conditioning and extinction in inhibitory avoidance (IA) task, impaired spatial memory in a recognition location memory task and enhanced negative feedback on the HPA axis following a dexamethasone suppression test. SPS rats also showed reduced hippocampal BDNF and enhanced apoptosis. Moderate treadmill exercise, fluoxetine and the combined treatment alleviated the SPS-induced alterations in terms of anxiety levels, HPA axis inhibition, IA conditioning and extinction, hippocampal BDNF and apoptosis markers. Furthermore, the combined treatment was more effective than fluoxetine alone, but in most tests, the effects of the combined treatment were similar to those of exercise alone, suggesting that exercise is the main factor in the beneficial effects of the combined therapy in PTSD patients.

Effect of moderate treadmill exercise together with modified hydroxyapatite chitosan composite hydrogel implantation on repair of full-thickness defects of articular cartilage in rats

Objective To investigate the effect of moderate treadmill exercise together with modified hydroxyapatite chitosan composite hydrogel(CS/HA-g-CS)implantation on repair of full-thickness defects of articular cartilage in rats. Methods Full-thickness cartilage defects were drilled in the patellar groove of bilateral femoral condyles in a total of 24 male SD rats before they were randomly assigned into 4 groups. The control group(BC group)was subjected to no exercise or CS/HA-g-CS implantation; the chitosan group(CHI group)to CS/HA-g-CS implantation without exercise; the moderate treadmill exercise group(MIR group)to exercise 4 weeks after modeling without CS/HA-g-CS implantation; the CHI + MIR group to moderate treadmill exercise plus CS/HA-g-CS implantation 4 weeks after modeling. Half of the animals were sacrificed at week 8 and half at week 16 after operation. Femoral condyles were harvested for gross observation and his-tochemical measurement by O’ Driscoll scoring system. mRNA expressions of glycosaminoglycan, collagen typeⅡ and BMP-2 were detected by RT-PCR. Results Gross observation revealed: at 8 weeks after modeling, the CHI + MIR group was significantly better than the other 3 groups, with the BC group in the poorest(P 0. 05). O' Driscoll scoring revealed: at both 8and 16 weeks after modeling, the CHI + MIR group was significantly better than the other 2 groups and the BC group significantly poorer than the other 3 groups(P 0. 05). The expressions of collagen type Ⅱ, glycosaminoglycan and BMP-2 were significantly higher in the CHI + MIR group than in the other 3 groups(P< 0. 05)and significantly lower in the BC group than in the other 3 groups(P< 0. 05). Conclusions Moderate treadmill exercise together with CS/HA-g-CS implantation has significant positive effects on repair of full-thickness defects of articular cartilage in rats than merely moderate treadmill exercise or CS/HA-g-CS implantation alone. The defective cartilage repaired by moderate treadmill exercise together with CS/HA-g-CS implantation contains more collagen type II and glycosaminoglycan and shows morphology of nearly normal cartilage. Key words: Exercise; Cartilage, articuler; Injuries; Hydroxyapatite chitosan composite hydrogel

Moderate Treadmill Exercise Protects Synaptic Plasticity of the Dentate Gyrus and Related Signaling Cascade in a Rat Model of Alzheimer's Disease.

The dentate gyrus (DG) of the hippocampus is known to be more resistant to the effects of various external factors than other hippocampal areas. This study investigated the neuroprotective effects of moderate treadmill exercise on early-phase long-term potentiation (E-LTP) and its molecular signaling pathways in the DG of amyloid β rat model of sporadic Alzheimer's disease (AD). Animals were preconditioned to run on treadmill for 4 weeks and concurrently received ICV infusion of Aβ₁₋₄₂ peptides (250 pmol/day) during the third and fourth weeks of exercise training. We utilized in vivo electrophysiological recordings to assess the effect of exercise and/or AD pathology on basal synaptic transmission and E-LTP magnitude of the perforant pathway synapses in urethane-anesthetized rats. Immunoblotting analysis was used to quantify changes in the levels of learning and memory-related key signaling molecules. The AD-impaired basal synaptic transmission and suppression of E-LTP in the DG were prevented by prior moderate treadmill exercise. In addition, exercise normalized the basal levels of memory and E-LTP-related signaling molecules including Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), calcineurin (PP2B), and brain-derived neurotrophic factor (BDNF). Exercise also prevented the reduction of phosphorylated CaMKII and aberrant increase of PP2B seen after E-LTP induction in amyloid-infused rats. Our data suggests that by restoring the balance of kinase-phosphatase, 4 weeks of moderate treadmill exercise prevents DG synaptic deficits and deleterious alterations in signaling pathways associated with AD.

Novel mechanistic insights into treadmill exercise based rescue of social defeat-induced anxiety-like behavior and memory impairment in rats

Social defeat (SD) induced stress causes physiological and behavioral deficits in rodents, including depression and anxiety-like behaviors, as well as memory impairment. Anxiolytic and mood elevating effects of physical exercise are also known. However, rescue effect of physical exercise in social defeat-induced anxiety, depression or memory impairment has not been addressed. The role of epigenetic mechanisms that potentially contribute to these rescue or protective effects is also not known. The present study investigated the effect of moderate treadmill exercise on anxiety-like behavior and memory function in rats subjected to SD using a modified version of the resident–intruder model for social stress (defeat). Changes in histone acetylation and histone-modifying enzymes were examined in hippocampus, amygdala and frontal cortex which are considered critical for anxiety, depression and cognition. Sprague Dawley rats were randomly assigned in four groups; control, exercised, social defeat, social defeat and exercise. At the end of the SD or control exposure lasting 30min daily for 7days, one group of SD rats was subjected to treadmill exercise for 2weeks, whereas the other SD group was handled without exercise. Anxiety-like behavior tests and radial arm water maze test suggested that moderate treadmill exercise rescued social defeat induced anxiety-like behavior and memory impairment. Moreover, exercise normalized SD-induced increase in oxidative stress, most likely by adjusting antioxidant response. Our data suggests involvement of epigenetic mechanisms including histone acetylation of H3 and modulation of methyl-CpG-binding in the hippocampus that might contribute to the rescue effects of exercise in SD-induced behavioral deficits in rats.

Moderate treadmill exercise rescues anxiety and depression-like behavior as well as memory impairment in a rat model of posttraumatic stress disorder

Post-traumatic stress disorder (PTSD) is a condition which can develop from exposure to a severe traumatic event such as those occurring during wars or natural disasters. Benzodiazepines and selective serotonin reuptake inhibitors (SSRIs) are considered the gold standard for PTSD treatment, but their side effects pose a serious problem. While regular physical exercise is regarded as a mood elevator and known to enhance cognitive function, its direct role in rescuing core symptoms of PTSD including anxiety and depression-like behaviors and cognitive impairment is unclear. In the present study using the single-prolonged stress (SPS) rat model of PTSD (2h restrain, 20min forced swimming, 15min rest, and 1–2min diethyl ether exposure), we examined the beneficial effect of moderate treadmill exercise on SPS-induced behavioral deficits including anxiety and depression-like behaviors and memory impairment. Male Wistar rats were randomly assigned into four groups: control (sedentary), exercised, SPS (no exercise), or SPS-exercised. Rats were exercised on a rodent treadmill for 14 consecutive days. Rats in all groups were tested for anxiety-like behaviors using open field (OF), light–dark and elevated-plus maze tests. All rats were tested for short-term and long-term memory in the radial arm water maze test. Rats were then sacrificed, blood was collected (for corticosterone levels), and individual organs (spleen, adrenals, and thymus) harvested. Results suggest that moderate physical exercise ameliorates SPS-induced behavioral deficits in rats.

Treadmill Exercise Induces Hippocampal Astroglial Alterations in Rats

Physical exercise effects on brain health and cognitive performance have been described. Synaptic remodeling in hippocampus induced by physical exercise has been described in animal models, but the underlying mechanisms remain poorly understood. Changes in astrocytes, the glial cells involved in synaptic remodeling, need more characterization. We investigated the effect of moderate treadmill exercise (20 min/day) for 4 weeks on some parameters of astrocytic activity in rat hippocampal slices, namely, glial fibrillary acidic protein (GFAP), glutamate uptake and glutamine synthetase (GS) activities, glutathione content, and S100B protein content and secretion, as well as brain-derived neurotrophic factor (BDNF) levels and glucose uptake activity in this tissue. Results show that moderate treadmill exercise was able to induce a decrease in GFAP content (evaluated by ELISA and immunohistochemistry) and an increase in GS activity. These changes could be mediated by corticosterone, whose levels were elevated in serum. BDNF, another putative mediator, was not altered in hippocampal tissue. Moreover, treadmill exercise caused a decrease in NO content. Our data indicate specific changes in astrocyte markers induced by physical exercise, the importance of studying astrocytes for understanding brain plasticity, as well as reinforce the relevance of physical exercise as a neuroprotective strategy.

Effect of Moderate Treadmill Exercise on Some Physiological Parameters in Untrained Beagle Dogs

The aim of the present study was to evaluate the modifications of some physiological parameters during moderate treadmill exercise in seven healthy Beagle dogs. All animals were submitted to treadmill exercise consisting of walking (15 min), trotting (20 min) and walking (10 min). At every step, rectal temperature (RT) was measured, and the mean heart rate (HR) was assessed. Venous blood samples were collected immediately before starting the treadmill exercise session (at rest), after the end of walking (15 min), trotting (20 min) and walking (10 min), and after 30 min of passive recovery. For immediate assessment of lactate and glucose concentration, blood was analyzed with portable blood lactate and blood glucose analyzers, respectively. Blood was also transferred into sterile glass tubes containing K(3)-ethylenediaminetetraacetic acid (K(3)-EDTA) for evaluation of red blood cells (RBC), white blood cells (WBC), platelets (PLT), hemoglobin (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). One-way repeated measures analysis of variance (ANOVA) showed a significant effect of treadmill exercise (P<0.05) on RT, HR, lactate, glucose, RBC and Hct. Considering these significant variations, the knowledge of RT, HR, glucose and lactate concentrations, RBC, and Hct, the most suitable and sensitive indicators of response to treadmill exercise in untrained dogs, is essential in order to evidence the individual levels of exercise tolerance, to investigate exercise-related problems and to design specific and individual treadmill protocols.

Adipose triglyceride lipase plays a key role in the supply of the working muscle with fatty acids

FAs are mobilized from triglyceride (TG) stores during exercise to supply the working muscle with energy. Mice deficient for adipose triglyceride lipase (ATGL-ko) exhibit defective lipolysis and accumulate TG in adipose tissue and muscle, suggesting that ATGL deficiency affects energy availability and substrate utilization in working muscle. In this study, we investigated the effect of moderate treadmill exercise on blood energy metabolites and liver glycogen stores in mice lacking ATGL. Because ATGL-ko mice exhibit massive accumulation of TG in the heart and cardiomyopathy, we also investigated a mouse model lacking ATGL in all tissues except cardiac muscle (ATGL-ko/CM). In contrast to ATGL-ko mice, these mice did not accumulate TG in the heart and had normal life expectancy. Exercise experiments revealed that ATGL-ko and ATGL-ko/CM mice are unable to increase circulating FA levels during exercise. The reduced availability of FA for energy conversion led to rapid depletion of liver glycogen stores and hypoglycemia. Together, our studies suggest that ATGL-ko mice cannot adjust circulating FA levels to the increased energy requirements of the working muscle, resulting in an increased use of carbohydrates for energy conversion. Thus, ATGL activity is required for proper energy supply of the skeletal muscle during exercise.

Chronic effects of FR139317 and enalapril on renal failure rats with moderate exercise.

We assessed the renal effects of moderate treadmill exercise in the spontaneously hypertensive rats (SHR) remnant kidney model of chronic renal failure (CRF). The effects of chronic administration of a specific endothelin (ET) subtype A (ETA) receptor antagonist, FR139317 (32 mg/kg/day i.p.) and an angiotensin-converting enzyme inhibitor, enalapril (2 mg/kg/day i.p.), in combination with moderate exercise were also investigated. Eight-week-old SHR were subjected to 5/6 nephrectomy. One week after surgery the rats were divided into five groups: (a) no treadmill running; (b) moderate treadmill running, 20 m/min for 60 min (Ex) per day; (c) Ex plus FR139317; (d) Ex plus enalapril; and (e) m-Ex plus enalapril in combination with FR139317, for 4 weeks. In SHR-CRF, Ex significantly attenuated the increase in urinary protein excretion. Enalapril significantly attenuated the increase in systolic blood pressure and urinary protein excretion. FR139317 at this dose did not show any antihypertensive or renal protective effect in this model. These results suggest that moderate exercise may protect renal function in SHR CRF. They also suggest that FR139317 may not have an additional antihypertensive and renal protective effect in this exercise model.

THE EFFECT OF TREADMILL EXERCISE ON THE DEVELOPMENT OF PROSTATE CANCER IN RATS 1195

It is now evident that both acute and chronic exercise have an effect on the immune system. Moderate exercise training has been shown to significantly increase serum immunoglobulins, monocytes, as well as NK cell number and activity. The influence of physical activity on prostate cancer is a topic which has not been well investigated. Therefore, the purpose of this study was to examine the effect of moderate treadmill exercise on the development of prostate cancer in rats. Forty male Lobund-Wistar rats were randomly assigned to aerobic exercise (AE: n=20) or control (C: n=20) groups. Aerobic exercise consisted of running on a motor-driven treadmill at 20 m/min (73.2 ± 12.6% VO2 max), 15 min/day, three times weekly for six weeks. Following exercise, all animals were inoculated with 1 × 106 transplantable rat prostate cancer (PA-III) subcutaneously on the back, above the sacral region (day = 0). The AE group exercised an additional 2 weeks post inoculation. Max VO2 did not change in either group during the initial six-week training period (AE: 65.52 ± 6.16 vs 65.72 ± 4.29; C: 65.79 ± 4.34 vs. 64.36 ± 4.86, ml/kg/min). At day 30, the number of rats displaying tumor (AE: 20 vs C: 18) and the total tumor volume (AE: 7305.2 ± 3313.4 vs C: 9134.9 ± 6509.6, mm3) did not differ between groups. Lung tissue collected from 10 AE and 10 C at day 30 showed no differences in metastatic lesions. In conclusion, the treadmill exercise protocol was not sufficient to elicit a training response and had no effect on the incidence or growth of prostate cancer in rats at day 30. Future studies need to consider a greater dose of exercise in order to determine its efficacy.