BACKGROUNDLittle is known about the value of (31)P-magnetic resonance spectroscopy ((31)P-MRS) in in vivo assessment of exhaustive exercise-induced injury in skeletal muscle. We aimed to evaluate the value of a (31)P-MRS study using the quadriceps femoris after a single bout of acute exhaustive swimming in rats, and the correlation between (31)P-MRS and histological changes.

METHODSSixty male Sprague-Dawley rats were randomly assigned to control, half-exhaustive, and exhaustive exercise groups. (31)P-MRS of the quadriceps femoris of the right lower limb was performed immediately after swimming exercise to detect Pi, PCr, and β-ATP. The Pi/PCr, Pi/β-ATP, PCr/β-ATP, and PCr/(PCr+Pi) were calculated and pH measured. Areas under the receiver operating characteristic curve (AUCs) were calculated to evaluate the diagnostic potential of (31)P-MRS in identifying and distinguishing the three groups. HE staining, electron microscopy and desmin immunostaining after imaging of the muscle were used as a reference standard. The correlation between (31)P-MRS and the mean absorbance (A value) of desmin staining were analyzed with the Pearson correlation test.

RESULTSPi, PCr, Pi/PCr, and PCr/(PCr+Pi) showed statistically significant intergroup differences (P < 0.05). AUCs of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were 0.905, 0.848, 0.930, and 0.930 for the control and half-exhaustive groups, while sensitivity and specificity were 90%/85%, 95%/55%, 95%/80%, and 90%/85%, respectively. The AUCs of Pi, PCr, Pi/PCr and PCr/(PCr+Pi) were 0.995, 0.980, 1.000, and 1.000 for the control and exhaustive groups, while sensitivity and specificity were 95%/90%, 100%/90%, 100%/95%, and 100%/95%, respectively. The AUCs of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were 0.735, 0.865, 0.903, and 0.903 for the half-exhaustive and exhaustive groups, while sensitivity and specificity were 80%/60%, 90%/75%, 95%/65%, and 95%/70%, respectively. In the half-exhaustive group, some muscle fibers exhibited edema in HE staining, and the unclear Z-discs and the mitochondria with vacuolar degeneration under electron microscopy. Compared with the half-exhaustive group, muscle fiber edema was increased in the exhaustive group, and the Z-discs were broken and the mitochondria exhibited marked vacuolar degeneration under electron microscopy. There were significant difference in A values of desmin staining in the right vastus lateralis among the control, half-exhaustive, and exhaustive groups with 0.58 ± 0.06, 0.30 ± 0.04, and 0.21 ± 0.02, respectively (P < 0.05). Histological examination also showed injury-induced changes in the vastus lateralis among the different intensities groups. Statistically a moderate correlation between (31)P-MRS and desmin was observed, the correlation coefficients of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were -0.706, 0.709, -0.726, and 0.791, respectively (P < 0.01).

CONCLUSIONS(31)P-MRS can effectively reflect the changes in energy metabolism in the skeletal muscle after a single bout of acute exhaustive swimming in rats. Based on the significant correlation between (31)P-MRS parameters and histological changes, the changes of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) can indirectly reflect the degree of exercise-induced injury.

Animals ; Energy Metabolism ; physiology ; Magnetic Resonance Spectroscopy ; methods ; Male ; Physical Conditioning, Animal ; physiology ; Quadriceps Muscle ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo examine the effects of continuous and intermittent exercises on obesity and fatty liver in rats fed with high-fat diet.

METHODSWistar rats were randomly assigned into routine diet (R) and high-fat diet (H) groups, and each group were subdivided into sedentary group (S), continuous exercise (CE) group, and intermittent exercise (IE) group (n=8). In the CE group, the rats were forced to swim continuously for 90 min once daily, and those in the IE group swam for 30 min for 3 times (at a 4-h interval) daily. Both the CE and IE groups exercised for 5 days a week for 8 consecutive weeks. After the experiment, the retroperitoneal, epididymal, and visceral white and brown adipose tissues, the liver, and the gastrocnemius muscle of the rats were weighed. The lipogenesis rate was determined by incorporation of (3)H(2)0 into saponified lipids, and the blood lipid profiles were analyzed. The body weight and food intake of the rats were recorded daily.

RESULTSIE appeared to be more efficient than CE in reducing the adverse effects of high-fat diet and sedentarism. Compared with CE, IE resulted in an improved lipid profile with reduced food intake, body weight gain, visceral and central adiposity, and fatty liver. The effect of high-fat diet and different exercises on weight gain, adiposity, fatty liver, and lipid profile in rats was associated to the manner of exercise, time of each session, age, gender, and length of observation period.

CONCLUSIONIntermittent exercise is an important nonpharmacological strategy to control obesity and the related complications.

Animals ; Diet, High-Fat ; Fatty Liver ; etiology ; therapy ; Male ; Obesity ; etiology ; therapy ; Physical Conditioning, Animal ; methods ; Rats ; Rats, Wistar

FIZZ/RELM is a new gene family named "found in inflammatory zone" (FIZZ) or "resistin-like molecule" (RELM). FIZZ1/RELMα is specifically expressed in lung tissue and associated with pulmonary inflammation. Chronic cigarette smoking up-regulates FIZZ1/RELMα expression in rat lung tissues, the mechanism of which is related to cigarette smoking-induced airway hyperresponsiveness. To investigate the effect of exercise training on chronic cigarette smoking-induced airway hyperresponsiveness and up-regulation of FIZZ1/RELMα, rat chronic cigarette smoking model was established. The rats were treated with regular exercise training and their airway responsiveness was measured. Hematoxylin and eosin (HE) staining, immunohistochemistry and in situ hybridization of lung tissues were performed to detect the expression of FIZZ1/RELMα. Results revealed that proper exercise training decreased airway hyperresponsiveness and pulmonary inflammation in rat chronic cigarette smoking model. Cigarette smoking increased the mRNA and protein levels of FIZZ1/RELMα, which were reversed by the proper exercise. It is concluded that proper exercise training prevents up-regulation of FIZZ1/RELMα induced by cigarette smoking, which may be involved in the mechanism of proper exercise training modulating airway hyperresponsiveness.
Animals ; Lung ; physiopathology ; Male ; Nerve Growth Factor ; metabolism ; Physical Conditioning, Animal ; methods ; Rats ; Rats, Sprague-Dawley ; Respiratory Hypersensitivity ; physiopathology ; Smoking ; physiopathology ; Up-Regulation

BACKGROUNDAerobic exercise can improve symptoms, reduce airway inflammation, and even ameliorate airway remodeling in asthmatic animals and patients. However, previous studies have focused mainly on the effect of aerobic exercise on steroid-sensitive asthma (SSA). The goals of this study were to determine the effect of low-intensity aerobic exercise training on airway hyperresponsiveness, inflammation, and remodeling in a rat model of steroid-resistant asthma (SRA) and to identify the potential mechanisms underlying these effects.

METHODSEndotoxin-free ovalbumin with or without lipopolysaccharide were applied to establish rat models of SRA and SSA, respectively. Airway hyperresponsiveness, inflammation, remodeling, expression of interleukin (IL)-25, IL-33, thymic stromal lymphopoietin (TSLP), high mobility group box-1 (HMGB1), and IL-17 in bronchoalveolar lavage fluid (BALF), and the role of dexamethasone (DXM) were compared between these two asthmatic rat models. The effect of low-intensity aerobic exercise training and anti-HMGB1 treatment on airway hyperresponsiveness, inflammation, and remodeling in SRA rats also was evaluated.

RESULTSSRA rats developed neutrophil-dominated airway inflammation ((29.5±4.1)% of the total cell numbers in BALF), whereas SSA rats developed eosinophil-dominated airway inflammation ((24.0±6.1)% of the total cell numbers in BALF). Compared with SSA rats, SRA rats had more severe airway hyperresponsiveness, lower levels of IL-25 ((33.6±10.3) vs. (104.8±24.9) pg/ml), IL-33 ((87.5±25.0) vs. (226.6±40.7) pg/ml), and TSLP ((1 933.2±899.5) vs. (7 224.0±992.1) pg/ml), and higher levels of HMGB1 ((21.2±4.5) vs. (5.4±1.6) ng/ml) and IL-17 ((780.5±261.7) vs. (291.4±76.4) pg/ml) in BALF (all P < 0.05). However, there was no significant difference in goblet cell hyperplasia, subepithelial collagen thickness, and airway smooth muscle remodeling between the two groups. Compared with control SSA rats, airway hyperresponsiveness, inflammation, and remodeling in SRA rats were less sensitive to DXM treatment. Anti-HMGB1 treatment attenuated airway hyperresponsiveness, inflammation, and remodeling in SRA rats to a certain extent and was accompanied by lower levels of IL-17 ((369.2±126.7) vs. (780.5±261.7) pg/ml in control SRA rats) in BALF (P < 0.05). Low-intensity aerobic exercise training decreased the expression of both HMGB1 ((14.1±2.9) vs. (21.2±4.5) ng/ml in control SRA rats) and IL-17 ((545.3±148.6) vs. (780.5±261.7) pg/ml in control SRA rats) in BALF (all P < 0.05) and was accompanied by improved airway hyperresponsiveness, inflammation, and remodeling in SRA rats (all P < 0.05).

CONCLUSIONSLow-intensity aerobic exercise training attenuated airway hyperresponsiveness, inflammation, and remodeling in a rat model of SRA. Decreased HMGB1 and IL-17 levels in BALF by aerobic exercise training at least partly contributed to the improvements of SRA.

Airway Remodeling ; physiology ; Animals ; Asthma ; drug therapy ; metabolism ; therapy ; HMGB1 Protein ; metabolism ; Male ; Physical Conditioning, Animal ; methods ; Rats ; Rats, Sprague-Dawley ; Respiratory System ; physiopathology

AIMTo explore the role of HO-1 in the exercise preconditioning protecting the rat myocardium from the relative myocardial ischemia/reperfusion injury (rI/R).

METHODS40 Wistar rats were divided into 5 groups randomly: control group (CN), relative ischemia/reperfusion group (IR), exercise preconditioning + relative ischemia-reperfusion group (EI), HO-1 revulsant group (HE) and exercise preconditioning + HO-1 inhibitor (EZ) group. We detected the cardiac function parameter--pressure-rate product (PRP), the levels of MDA in coronary effluent and the activity of HO-1.

RESULTSThe activities of HO-1 of EI group and HE group were higher significantly than the IR group. EZ group was lower than EI group. There was significant difference between EI group and HE group. The recovery rate of PRP in the 60 min point of reperfusion of EI group was higher significantly than IR group. EZ group was lower than EI group. There was significant difference between HE group and IR group in 30 min point of reperfusion. The levels of MDA in coronary effluent after rI/R of EI group, EZ group and HE group were lower significantly than IR group. There was significant difference between EI group and EZ group.

CONCLUSIONEP can activate the HO-1 which can ameliorate the rI/R injury occurred after 24 hours.

Animals ; Heme Oxygenase (Decyclizing) ; physiology ; Ischemic Preconditioning ; methods ; Male ; Myocardial Reperfusion Injury ; prevention & control ; Physical Conditioning, Animal ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVETo observe the effect of transplantation of allogeneic adipose-derived stem cells (ADSCs) on serum biochemical indicators and sporting ability in highly endurance-trained rats from a fasciological perspective.

METHODSThe ADSCs were cultured in vitro. Forty male Wistar rats were randomized into 4 equal groups, namely the blank control group, overtraining (model) group, transplantation without training group and overtraining plus transplantation group. The rats in the two overtraining groups were subjected to exhaustive swimming for 1 week, and in the two transplantation groups, cultured allogeneic ADSCs (2×10(6)/ml) were injected via the tail vein. The exhaustion time in swimming and the serum levels of BUN, LDH, BLa, and Hb of the rats were recorded after the treatments.

RESULTSThe rats in the model group showed significantly increased serum BUN, LDH and BLa levels and decreased Hb level with a extended exhaustion time as compared with those in the blank control group (P<0.01). The BUN, LDH and BLa was significantly lower, Hb level higher and the exhaustion time significantly longer in the overtraining plus transplantation group than those in the model group (P<0.01).

CONCLUSIONSADSCs can effectively prolong the exhaustion time of rats during exhaustive swimming and enhance their sporting ability.

Adipose Tissue ; cytology ; Animals ; Blood Urea Nitrogen ; Fatigue ; prevention & control ; Hydro-Lyases ; blood ; Lactic Acid ; blood ; Male ; Physical Conditioning, Animal ; physiology ; Physical Exertion ; physiology ; Rats ; Rats, Wistar ; Stem Cell Transplantation ; methods ; Swimming

Objective: To investigate the effect of aerobic exercise on the spermatogenic function of male rats and screen out differentially expressed proteins related to spermatonesis-regulation by proteomic analysis. METHODS: We randomly divided 24 SD male rats into groups A (non-exercise control), B (exercise), and C (weight-bearing exercise), those in the latter two groups made to swim for 60 minutes a day and those in group C bearing a load 3% of the body weight, both 6 times a week for 9 weeks. At 24 hours after the last exercise, we obtained the sperm count, measured the levels of such serum reproductive hormones as testosterone (T), luteotrophic hormone (LH), follicle-stimulating hormone (FSH), and gonadotrophin-releasing hormone (GnRH), and employed isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analysis of the testicular tissue. RESULTS: Compared with group A, group C showed significant increases in sperm concentration (［2.12 ± 0.43］ vs ［3.54 ± 0.52］ ×10⁶/ml, P <0.01) and the levels of serum LH (［35.99 ± 2.90］ vs ［38.96 ± 1.34］ IU/L, P <0.01) and T (［19.99 ± 0.25］ vs ［21.36 ± 0.53］ nmol/L, P <0.01), but no statistically significant differences in GnRH (［623.95 ± 41.44］ vs ［641.82 ± 42.78］ ng/L, P >0.05) and FSH (［20.49 ± 2.44］ vs ［22.29 ± 2.31］ IU/L, P >0.05). No significant changes were observed in sperm concentration or reproductive hormone levels in group B as compared with A. Group B exhibited obviously more mature sperm and cell layers in the seminiferous epithelium than group A. A total of 47 differentially expressed proteins were identified, of which 37 were up-regulated and the other 10 down-regulated. In addition, another 5 significantly differentially expressed proteins closely related to reproductive function were identified, including up-regulated Anx A1, GPX3, Rimbp3, and Dpy19l2 and down-regulated CYP17. Enrichment analysis showed that the differentially expressed proteins were mainly involved in extracellular matrix-receptor interaction, protein digestion and absorption, and focal adhesion pathways. CONCLUSIONS Proper-intensity exercise can improve the spermatogenic function of rats. Aerobic exercise promotes spermatogenesis mainly by up-regulating the expressions of the proteins related to the production and differentiation of spermatozoa.
Animals ; Follicle Stimulating Hormone ; blood ; Gonadotropin-Releasing Hormone ; blood ; Luteinizing Hormone ; Male ; Physical Conditioning, Animal ; methods ; Proteomics ; methods ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reproduction ; Resistance Training ; methods ; Sperm Count ; Spermatogenesis ; physiology ; Spermatozoa ; Testis ; Testosterone ; blood

Animals ; Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism* ; MEF2 Transcription Factors/metabolism* ; Muscle Fibers, Skeletal/metabolism* ; Muscle, Skeletal/metabolism* ; Myogenic Regulatory Factors/metabolism* ; Physical Conditioning, Animal/methods* ; Rats ; Signal Transduction

Objective: To investigate the effects of continuing exercise and load-bearing interval exercise on skeletal muscle tissue cell morphology, Ras-related proteins 5 (Rab5) mRNA and protein expression and glucose metabolism in skeletal muscle of type 2 diabetic mellitus (T2DM) rats. Methods: Eight SD rats were selected as controls group (CR), the others SD rats were fed with high fat and high sugar diet for 6 weeks before injecting STZ (35 mg/kg) to construct the T2DM model. Twenty-four T2DM rats were randomly devided into T2DM model group (DRM), continuing exercise group (DCRE) and load-bearing interval exercise group (DWRE), 8 rats in each group. DCRE exercise protocol, that was 15 m/min (10 min), 20 m/min (40 min), 15 m/min (10 min), during the first 1～2 weeks, and 18 m/min (10 min), 25 m/min (40 min), 15 m/min (10 min), during the second 3～8 weeks. DWRE exercise protocol: load weight 15% / 1～2 weeks, 30% / 3～4 weeks, 45% / 5～8 weeks, with 15 m/min (5 min), 12 groups and 3 min rest between groups. After 8 weeks, pathological and morphological changes of skeletal muscle were observed by HE. Rab5 and Glucose transporte 4 (GLUT4) mRNA expressions of skeletal muscle were tested by qRT-PCR. Rab5 protein expression in skeletal muscle was tested by immunofluorescence histochemistry and Western blot, and plasma Rab5 and Glycosylated Hemoglobin (GHb) concentrations were detected by ELISA. Results: Comparison with CR, DRM showed pathological damage of skeletal muscle, the expressions of Rab5 mRNA, protein and GLUT4 mRNA were all decreased in skeletal muscle (P＜0.01), the serum levels of Rab5 and GHb were both significantly elevated (P＜0.01). Comparison with DRM, both DCRE and DWRE significantly improved pathological damages of skeletal muscle, the expressions of Rab5 mRNA, protein and GLUT4 mRNA were all increased in skeletal muscle (P＜ 0.05, P＜0.01), the serum levels of Rab5 and GHb were decreased (P＜0.05, P＜0.01), and there was no statistical difference between DCRE and DWRE groups (P＞0.05). Conclusion: Two exercise modes can improve the pathological injury of skeletal muscle in type 2 diabetic rats, and enhance GLUT4 transport capacity by improving the expression of Rab5 gene and protein in skeletal muscle, and alleviate the imbalance of glucose metabolism homeostasis in skeletal muscle. However, there was no significant difference between the effects of two exercise modes on Rab5 protein and glucose metabolism in skeletal muscle.
Animals ; Diabetes Mellitus, Experimental/metabolism* ; Diabetes Mellitus, Type 2/metabolism* ; Glucose/metabolism* ; Glycated Hemoglobin ; Insulin ; Muscle, Skeletal/metabolism* ; Physical Conditioning, Animal/methods* ; RNA, Messenger/metabolism* ; Rats ; Rats, Sprague-Dawley ; rab5 GTP-Binding Proteins/metabolism*

Objective: To observe the effects of swimming plus medication on the expressions of cytokines in rats with chronic abacterial prostatitis (CAP). METHODS: Forty healthy adult male SD rats were randomly divided into five groups of equal number, normal control, CAP model control, medication, exercise therapy, and exercise + medication. The CAP model was made by Xiaozhiling injection, and at 7 days after modeling, the rats in the medication and exercise + medication groups were treated intragastrically with Qianlie Shutong Capsules (0.016 g/ml) at 20 ml per kg of the body weight qd, those in the exercise therapy and exercise + medication groups were made swim at a regular time once a day, 35 minutes on the first day and 5 minutes more on the second until 50 minutes once, for 4 successive weeks, and those in the normal control, model control and exercise therapy groups received normal saline only. After 14 and 28 days of treatment, all the rats were killed and their prostates harvested for observation of histopathological changes and determination of the expressions of TNF- α, IL-1β and IL-6 in the prostatic tissue homogenate by ELISA. RESULTS: After 14 days of treatment, the expression levels of TNF-α, IL-1β and IL-6 were significantly elevated in the groups of CAP model control (［183.08±8.07］ pg/ml, ［57.55±3.53］ pg/ml and ［256.15±13.95］ ng/L), medication (［118.49±8.06］ pg/ml, ［42.64±4.64 ］ pg/ml and ［200.74±9.33］ ng/L), exercise therapy (［169.63±10.64］ pg/ml, ［50.45±5.71］ pg/ml and ［245.23±6.49］ ng/L), and exercise + medication (［107.82±7.81］ pg/ml, ［40.35±6.93］ pg/ml and ［187.04±10.85］ ng/L) as compared with those in the normal control (［20.36±1.82］ pg/ml, ［14.64±1.91］ pg/ml and ［70.58±2.09］ ng/L) (P<0.05). At 28 days, the levels of TNF- α, IL-1β, IL-6 were remarkably lower in the exercise + medication group (［29.30±3.78］ pg/ml, ［16.91±1.24］ pg/ml and ［ 88.65±6.74］ ng/L) than in the medication group (［39.67±3.19］ pg/ml, ［26.27±3.49］ pg/ml and ［110.26±6.33］ ng/L) (P<0.05) and close to those of the normal control group (［19.34±1.76］ pg/ml, ［13.68±1.06］ pg/ml and ［71.34±2.50］ ng/L). During the treatment, no obvious pathological changes were found in the prostate tissue of the normal control rats, while significant chronic prostatic inflammation was observed in the CAP models, and the inflammation was relieved in different degrees after intervention, most significantly in the exercise + medication group. CONCLUSIONS Swimming can relieve prostatic inflammation and swimming plus medication can effectively reduce the expressions of cytokines and alleviate histological damage in the prostatic tissue of CAP rats.
Animals ; Chronic Disease ; Combined Modality Therapy ; methods ; Cytokines ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Interleukin-1beta ; metabolism ; Interleukin-6 ; metabolism ; Male ; Physical Conditioning, Animal ; Prostatitis ; metabolism ; therapy ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Swimming ; Time Factors ; Tumor Necrosis Factor-alpha ; metabolism