Exhaustive Swimming Exercise Research Articles

Intracerebroventricular administration of the exercise hormone irisin or acute strenuous exercise alleviates epileptic seizure-induced neuroinflammation and improves memory dysfunction in rats

BackgroundStatus epilepticus is a common and potentially life-threatening neurological emergency with a high risk for cognitive and neurobiological impairment. Our aim was to evaluate the neuroprotective effects of centrally administered irisin and acute exhausting exercise against oxidative brain injury and memory dysfunction due to a pentylenetetrazole (PTZ)-induced single seizure. Male Sprague Dawley rats with intracerebroventricular (icv) cannulas were randomly divided into intraperitoneally (ip) saline-injected control and PTZ-injected (45 mg/kg) seizure groups. Both the control and PTZ groups were then treated with irisin (7.5 µg/kg, 2 µl, icv), saline (2 µl, icv) or were forced to an acute bout of strenuous exercise before the ip injection of saline (control) or PTZ. Seizures were evaluated using the Racine score. To evaluate memory performance, a passive avoidance test was performed before and after PTZ injection. Following euthanasia at the 24th hour of seizure induction, brain tissues were removed for histopathological examination and for evaluating oxidative damage, antioxidant capacity, and neurotransmitter levels.ResultsGlutamate/GABA imbalance observed in PTZ rats was corrected by irisin administration (p < 0.001/p < 0.01), while irisin prevented the generation of reactive oxygen species and lipid peroxidation (p < 0.05 − 0.001) and replenished the antioxidant catalase and glutathione levels (p < 0.01–0.01) in the cerebral tissue, and reduced the histologically evident neuronal injury due to a single seizure (p < 0.05 − 0.01). Irisin also delayed the onset of seizures (p < 0.05) and improved memory dysfunction (p < 0.05), but did not affect the severity of seizures. The acute exhaustive swimming exercise completed before PTZ-seizure depressed glutamate level (p < 0.001), maintained the oxidant/antioxidant balance, alleviated neuronal injury (p < 0.05 − 0.01) and upregulated cerebral BDNF expression (p < 0.05).ConclusionIn conclusion, acute high-intensity exercise or exogenously administered irisin provides neuroprotection by maintaining the balance of excitatory/inhibitory neurotransmitters and oxidant/antioxidant systems.

Effect of Rhodiola Rosea Supplement on Exhaustive Swimming Test and Physical Fatigue in Male Institute of Cancer Research Mice

Background Fatigue decreases exercise performance, and affects work capacity and quality of life. Functional supplement use is one of the common methods to alleviate fatigue. Rhodiola rosea (RHR) exerts antioxidative and anti-inflammatory effects due to its rich glycosides and has the potential to resist fatigue. Therefore, this study aims to investigate the effects of the RHR supplement on physical fatigue induced by exhaustive swimming exercise. Methods Forty institute of cancer research (ICR) mice were divided and assigned to one of four treatment groups (0, 600, 1200, and 3000 mg/kg body weight), with 10 animals in each group. After four weeks of RHR supplement intervention, swimming tests were conducted to assess exercise endurance, the accumulation of blood fatigue markers, and tissue glycogen storage. Results The results showed that after four weeks of the RHR supplement intervention, the exhaustive swimming time significantly increased in three treatment groups with a dose-dependence effect. The accumulation of blood fatigue substances (lactate, blood urea nitrogen (BUN), creatine kinase (CK) was significantly decreased, and glycogen content in the liver and muscle was elevated. Conclusion RHR supplements possess the capacity to enhance exercise performance and prevent exercise-induced fatigue. It is suitable to develop an RHR supplement as a dietary supplement for anti-fatigue.

Arı Sütünün Tüketici Egzersize Bağlı Oksidatif Stres Üzerindeki Rolü

In this study, the effects of Royal Jelly (RJ) on oxidative stress caused by exhaustive swimming exercise in rat tissues were evaluated. Methods: Twenty four male Wistar albino rats were indiscriminately distributed into four experimental groups: Sedentary control (SC); SC with administration of RJ (100 mg kg-1) (SC + RJ); exhaustive swimming exercise (E); Exhaustive swimming exercise with administration of RJ (100 mg kg-1) (E + RJ). 100 mg kg-1 of RJ were dissolved in drinking water. Rats in the SC+RJ and E+RJ groups supplemented with RJ (100 mg kg-1) orally once a day for two weeks. Rats in groups E and E+RJ subjected to acute exhaustive swimming exercise on the 14th day of the study, then some biochemical parameters related to oxidative stress of all groups were measured. Results: The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), blood urea nitrogen (BUN) and creatinine (CRE) levels significantly raised in the exercised rats compared with the sedentary rats (P &lt; 0.05). The decreased superoxide dismutase (SOD), glutathione peroxidase (GSHPx), and catalase (CAT) activities of muscular and hepatic tissues significantly increased and the high malondialdehyde (MDA) levels of muscular, hepatic and kidney tissues significantly reduced in exercised rats treated with RJ (P &lt; 0.05). Conclucion: Collectively, in this study, protective effects of RJ on tissues against oxidative damage after exhaustive exercise were observed.

Melatonin Potentiates Exercise-Induced Increases in Skeletal Muscle PGC-1α and Optimizes Glycogen Replenishment.

Compelling evidence has demonstrated the effect of melatonin on exhaustive exercise tolerance and its modulatory role in muscle energy substrates at the end of exercise. In line with this, PGC-1α and NRF-1 also seem to act on physical exercise tolerance and metabolic recovery after exercise. However, the literature still lacks reports on these proteins after exercise until exhaustion for animals treated with melatonin. Thus, the aim of the current study was to determine the effects of acute melatonin administration on muscle PGC-1α and NRF-1, and its modulatory role in glycogen and triglyceride contents in rats subjected to exhaustive swimming exercise at an intensity corresponding to the anaerobic lactacidemic threshold (iLAn). In a randomized controlled trial design, thirty-nine Wistar rats were allocated into four groups: control (CG = 10), rats treated with melatonin (MG = 9), rats submitted to exercise (EXG = 10), and rats treated with melatonin and submitted to exercise (MEXG = 10). Forty-eight hours after the graded exercise test, the animals received melatonin (10 mg/kg) or vehicles 30 min prior to time to exhaustion test in the iLAn (tlim). Three hours after tlim the animals were euthanized, followed by muscle collection for specific analyses: soleus muscles for immunofluorescence, gluteus maximus, red and white gastrocnemius for the assessment of glycogen and triglyceride contents, and liver for the measurement of glycogen content. Student t-test for independent samples, two-way ANOVA, and Newman keuls post hoc test were used. MEXG swam 120.3% more than animals treated with vehicle (EXG; p < 0.01). PGC-1α and NRF-1 were higher in MEXG with respect to the CG (p < 0.05); however, only PGC-1α was higher for MEXG when compared to EXG. Melatonin reduced the triglyceride content in gluteus maximus, red and white gastrocnemius (F = 6.66, F = 4.51, and F = 6.02, p < 0.05). The glycogen content in red gastrocnemius was higher in MEXG than in CG (p = 0.01), but not in EXG (p > 0.05). In conclusion, melatonin was found to enhance exercise tolerance, potentiate exercise-mediated increases in PGC-1α, decrease muscle triglyceride content and increase muscle glycogen 3 h after exhaustive exercise, rapidly providing a better cellular metabolic environment for future efforts.

Acute melatonin administration improves exercise tolerance and the metabolic recovery after exhaustive effort

The present study investigated the effects of acute melatonin administration on the biomarkers of energy substrates, GLUT4, and FAT/CD36 of skeletal muscle and its performance in rats subjected to exhaustive swimming exercise at an intensity corresponding to the maximal aerobic capacity (tlim). The incremental test was performed to individually determine the exercise intensity prescription and 48 h after, the animals received melatonin (10 mg·kg−1) or vehicles 30 min prior to tlim. Afterwards, the animals were euthanized 1 or 3 h after the exhaustion for blood and muscles storage. The experiment 1 found that melatonin increased the content of glycogen and GLUT4 in skeletal muscles of the animals that were euthanized 1 (p < 0.05; 22.33% and 41.87%) and 3 h (p < 0.05; 37.62% and 57.87%) after the last procedures. In experiment 2, melatonin enhanced the tlim (p = 0.01; 49.42%), the glycogen content (p < 0.05; 40.03%), GLUT4 and FAT/CD36 in exercised skeletal muscles (F = 26.83 and F = 25.28, p < 0.01). In summary, melatonin increased energy substrate availability prior to exercise, improved the exercise tolerance, and accelerated the recovery of muscle energy substrates after the tlim, possibly through GLUT4 and FAT/CD36.

Anti-fatigue Effects of Santé Premium Silver Perch Essence on Exhaustive Swimming Exercise Performance in Rats.

Aim: Fish soup is a traditional Chinese food usually offered as a healthy supplement to elders, pregnant women and persons who just had surgery. Silver perch (Santé premium silver perch essence, SPSPE) extract contains various quality proteins, collagen, minerals, trace elements, and branch chain amino acids (BCAA) that could help individuals recover from exhaustion and control body weight. However, there are very limited studies exploring the effects of fish extracts on exercise performance and fatigue, and relevant physiological mechanisms. Therefore, the purpose of this study was to investigate the effects of chronic SPSPE administration on exhaustive exercise performance.Method: Male Wistar rats weighing around 250 g were divided into 4 groups: Control, 1X SPSPE (6.2 ml/kg), 2X SPSPE (12.4 ml/kg) and 5X SPSPE (31.0 ml/kg). Rats were administrated SPSPE by oral gavage feeding every day for 33 days. Their body weight were measured every week. Before and after the exhaustive swimming test, the blood was collected for circulating lactate, glucose, ammonia, hormones, and myoglobin analysis. Rats were sacrificed after performing an exhaustive swimming exercise test. The liver tissues were collected for glycogen content and H&E staining.Results: After the administration of 1X and 5X SPSPE, swimming fatigue was significantly delayed (p = 0.024). There was no difference in the hormone plasma level between the control and SPSPE groups. The induction of plasma corticosterone and TBARS by exhaustive swimming exercise could be decreased by SPSPE administration. The increased plasma myoglobin concentration from exhaustive swimming exercise was weakened by SPSPE supplementation. The higher glycogen sparing contained in liver tissue was observed in SPSPE-treated groups (p < 0.05).Conclusion: SPSPE could efficiently delay swimming fatigue through sparing of liver glycogen and attenuation of plasma TBARS, myoglobin induction by exhaustive exercise. Our findings provide a scientific-based fundamental information and better understanding for developing a fish extract-based anti-fatigue supplement.

Effects of sildenafil citrate on peripheral fatigue and exercise performance after exhaustive swimming exercise in rats.

Sildenafil citrate is a potent and selective inhibitor of phosphodiesterase type-5 used to treat erectile dysfunction. We investigated the effects of sildenafil citrate treatment on peripheral fatigue and exercise performance after exhaustive swimming exercise in rats. The rats in the sildenafil citrate-treated groups received sildenafil citrate orally once a day for 14 consecutive days at respective dosage. On the 14 days after starting experiment, each animal was submitted to swimming test with intensity equivalent to overload. The exhaustion was defined as a state in which coordinated movements did not return to the water surface for breathing within 10 sec. Western blot for monocarboxylate transporter (MCT)1, MCT4, and neuronal nitric oxide synthase (nNOS) were performed. Exhaustive swimming exercise decreased time of exhaustion and increased lactate concentration, however, sildenafil citrate enhanced time of exhaustion and decreased lactate concentration. Exhaustive swimming exercise increased MCT1 and MCT4 expressions in the gastrocnemius muscles and sildenafil citrate further enhanced MCT1 and MCT4 expressions in the exhaustive swimming exercise rats. Exhaustive swimming exercise decreased nNOS expression in the gastrocnemius muscles and sildenafil citrate enhanced nNOS expression in the exhaustive swimming exercise rats. The most potent effect appeared in the 20-mg/kg sildenafil citrate. Sildenafil citrate might be proposed as a potential ergogenic aid through antiperipheral fatigue.

Effect of sildenafil citrate on brain central fatigue after exhaustive swimming exercise in rats.

Sildenafil citrate, a potent and selective inhibitor of phosphodiesterase type-5, is used clinically to treat erectile dysfunction and pulmonary arterial hypertension. We investigated the effect of sildenafil citrate on brain central fatigue through serotonin (5-hydroxytryptamine, 5-HT) synthesis after exhaustive swimming exercise in rats. The rats in the sildenafil citrate-treated groups received sildenafil citrate orally once a day for 14 consecutive days at respective dosage. On the 14 days after starting experiment, each animal was submitted to swimming test with intensity equivalent to overload. The exhaustion was defined as a state in which coordinated movements did not return to the water surface for breathing within 10 sec. Immunohistochemistry for 5-HT, tryptophan hydroxylase (TPH), and western blot for serotonergic type 1A (5-HT1A) receptor and 5-HT transporter (5-HTT) were performed. Exhaustive swimming exercise increased 5-HT and TPH expressions in the dorsal raphe and sildenafil citrate suppressed 5-HT and TPH expressions in the exhaustive swimming exercise rats. Exhaustive swimming exercise increased 5-HT1A receptor and 5-HTT expressions in the dorsal raphe and sildenafil citrate suppressed 5-HT1A receptor and 5-HTT expressions in the exhaustive swimming exercise rats. The significant suppressing effect appeared in the 20-mg/kg sildenafil citrate. Sildenafil citrate might be proposed as a potential ergogenic aid through anticentral fatigue.

Lifetime overproduction of circulating angiotensin-(1-7) in rats attenuates the increase in skeletal muscle damage biomarkers after exhaustive exercise.

Angiotensin-(1-7) (Ang-[1-7]) can modulate glucose metabolism and protect against muscular damage. The aim of this study was to investigate the influence of lifetime increase of circulating levels of Ang-(1-7) at exhaustive swimming exercise (ESE). Sprague-Dawley (SD) and transgenic rats TGR(A1-7)3292 (TR) which overproduce Ang-(1-7) (2.5-fold increase) were submitted to ESE. The data showed no differences in time to exhaustion (SD: 4.90 ± 1.37 h vs. TR: 5.15 ± 1.15 h), creatine kinase, and transforming growth factor beta (TGF-β). Lactate dehydrogenase (SD: 219.9 ± 12.04 U/L vs. TR: 143.9 ± 35.21 U/L) and α-actinin (SD: 336.7 ± 104.5 U/L vs. TR: 224.6 ± 82.45 U/L) values were significantly lower in TR. There was a significant decrease in the range of blood glucose levels (SD: -41.4 ± 28.32 mg/dl vs. TR: -13.08 ± 39.63 mg/dl) in SD rats. Muscle (SD: 0.06 ± 0.02 mg/g vs. TR: 0.13 ± 0.01 mg/g) and hepatic glycogen (SD: 0.66 ± 0.36 mg/g vs. TG: 2.24 ± 1.85 mg/g) in TR were higher. The TR presented attenuation of the increase in skeletal muscle damage biomarkers and of the changes in glucose metabolism after ESE.

Nigella sativa seed extract attenuates the fatigue induced by exhaustive swimming in rats.

In previous studies, Nigella sativa (NS) has been studied due to its various physiological and pharmacological activities. However, evidence on the effects of NS on physical fatigue following exhaustive swimming remains limited. In the present study, the authors evaluated the potential beneficial effects of NS against the fatigue activity following exhaustive swimming. Rats were orally administered with NS extract (2 g/kg/day) for 21 days, and the anti-fatigue effect was assessed by exhaustive swimming exercise. The presented results indicated that pre-treatment of NS extract significantly increased the time to exhaustion. In hemodynamic parameters, NS extract increased blood pO2 and O2sat, but decreased pCO2. For underlying mechanisms, NS extract protected depletion of energy, indicated by increased levels of blood pH, glucose and tissue glycogen contents, and decreased levels of blood lactate, tissue lactic dehydrogenase and creatine kinase, when the NS extract was pre-treated. In addition, the NS extract inhibited oxidative stress following exhaustive swimming, as reflected by the results of increased levels of superoxide dismutase and redox ratio, and decreased the level of malondialdehyde when the NS extract was pre-treated. Collectively, the present study demonstrated that NS extract has an anti-fatigue activity against exhaustive swimming by energy restoration and oxidative-stress defense.

Short-term effects of troxerutin (vitamin P4) on muscle fatigue and gene expression of Bcl-2 and Bax in the hepatic tissue of rats.

In the current study, the effects of troxerutin (TRX) on muscle fatigue and gene expression of Bcl-2 and Bax in the hepatic tissue of rats was investigated. Forty male Wistar rats were randomly divided into 4 groups and designated as control and TRX treatment at 75 (TRX75), 150 (TRX150), and 300 mg/kg per day (TRX300). The treated groups and control group received TRX and water orally for 7 days. After an exhaustive swimming test on the 7th day, all animals were euthanized immediately and several biochemical parameters related to fatigue and gene expression of Bcl-2 and Bax in the hepatic tissue were measured. Our results showed that the exhaustion swimming time in the TRX300 groups significantly increased 1.2-fold compared with the control group (P < 0.001). TRX300 significantly reduced ALT (P < 0.05) activity and increased liver SOD activity compared with the control group (P < 0.01). Additionally, TRX significantly reduced the liver mRNA expressions of Bax (P < 0.001) and increased the Bcl-2/Bax ratio (P < 0.001) compared with the control group. Based on our data, TRX possesses anti-apoptotic and hepatoprotective action following exhaustive swimming exercise.

Attenuated Oxidative Stress following Acute Exhaustive Swimming Exercise Was Accompanied with Modified Gene Expression Profiles of Apoptosis in the Skeletal Muscle of Mice.

Purpose. The purpose of the present study was to investigate the effect of acute exhaustive swimming exercise on apoptosis in the skeletal muscle of mice. Method. C57BL/6 mice were averagely divided into seven groups. One group was used as control (C), while the remaining six groups went through one-time exhaustive swimming exercise and were terminated at 0 h, 2 h, 6 h, 12 h, 24 h, and 48 h upon completion of exercise. Result. ABTS was significantly lowered at 12 h and 48 h after exercise. The MDA level was significantly decreased at any time points sampled following exercise. Total SOD activity was significantly decreased at 6 h, 12 h, 24 h, and 48 h after exercise. Neither mRNA of Bax nor Bax/Bcl-2 ratio was significantly altered by exercise. mRNA of Bcl-2 was significantly decreased since 6 h after exercise. mRNA and protein expressions of PGC-1α were significantly increased at different time points following exercise. Conclusion. Cellular oxidative stress level was decreased following low intensity, long duration acute exhaustive swimming exercise in mice, and the enzymatic antioxidant capacity was compromised. Apoptosis of the skeletal muscle was inhibited, which could partially be explained by the enhanced level of PGC-1α.

Anti-Fatigue and Antioxidant Activity of the Polysaccharides Isolated from Millettiae speciosae Champ. Leguminosae.

Millettiae speciosae Champ. Leguminosae (MSC), is a well-known Chinese herb traditionally used as food material and medicine for enhancing physical strength. Our preliminary study found that the aqueous extract of this herb (MSE) had an anti-fatigue effect. In this paper, we further separated MSE into total polysaccharides (MSP) and supernatant (MSS) by alcohol precipitation, and explored which fraction was active for its anti-fatigue effect. Mice were orally administered with MSP or MSS at the doses of 200, 400, and 800 mg/kg for 20 days and the anti-fatigue effect was assessed by exhaustive swimming exercise (ESE). The biochemical parameters related to fatigue after ESE and the in vitro antioxidant activity of active fraction were determined. Our results showed that MSP, instead of MSS, significantly extended the swimming time to exhaustion (p < 0.05), indicating that MSP is responsible for the anti-fatigue effect of MSE. In addition, MSP treatment increased the levels of glucose (Glu) and muscle glycogen, whereas it decreased the accumulations of blood urea nitrogen (BUN) and lactic acid (Lac). Moreover, ESE increased the levels of creatine phosphokinase (CK), lactic dehydrogenase (LDH), and malondialdehyde (MDA) but reduced superoxide dismutase (SOD) and glutathione (GSH) in plasma. In contrast, MSP inhibited all the above changes relating to fatigue. Furthermore, an in vitro antioxidant test revealed that MSP dose-dependently scavenged ·OH and DPPH free radicals. Taken together, these findings strongly suggested that MSP was able to alleviate physical fatigue by increasing energy resources and decreasing accumulation of detrimental metabolites. The antioxidant activity may crucially contribute to the observed anti-fatigue effect of MSP.

The Protective Effects of Salidroside from Exhaustive Exercise-Induced Heart Injury by Enhancing the PGC-1 α -NRF1/NRF2 Pathway and Mitochondrial Respiratory Function in Rats.

Objective. To test the hypothesis that salidroside (SAL) can protect heart from exhaustive exercise-induced injury by enhancing mitochondrial respiratory function and mitochondrial biogenesis key signaling pathway PGC-1α–NRF1/NRF2 in rats. Methods. Male Sprague-Dawley rats were divided into 4 groups: sedentary (C), exhaustive exercise (EE), low-dose SAL (LS), and high-dose SAL (HS). After one-time exhaustive swimming exercise, we measured the changes in cardiomyocyte ultrastructure and cardiac marker enzymes and mitochondrial electron transport system (ETS) complexes activities in situ. We also measured mitochondrial biogenesis master regulator PGC-1α and its downstream transcription factors, NRF1 and NRF2, expression at gene and protein levels. Results. Compared to C group, the EE group showed marked myocardium ultrastructure injury and decrease of mitochondrial respiratory function (P < 0.05) and protein levels of PGC-1α, NRF1, and NRF2 (P < 0.05) but a significant increase of PGC-1α, NRF1, and NRF2 genes levels (P < 0.05); compared to EE group, SAL ameliorated myocardium injury, increased mitochondrial respiratory function (P < 0.05), and elevated both gene and protein levels of PGC-1α, NRF-1, and NRF-2. Conclusion. Salidroside can protect the heart from exhaustive exercise-induced injury. It might act by improving myocardial mitochondrial respiratory function by stimulating the expression of PGC-1α–NRF1/NRF2 pathway.

Effect effects of &lt;i&gt;Auricularia auricula&lt;/i&gt; polysaccharides on exhaustive swimming exercise-induced oxidative stress in mice

Purpose: To determine the effects of polysaccharides from Auricularia auricula (AAPs) on exerciseinduced oxidative stress in mice.Methods: The animals were divided into four groups: control (C), low, middle, and high-dose AAPstreated (LA, MA, and HA, respectively). C group received physiological saline solution while AAPstreated groups received different doses of AAPs (50, 100, and 200 mg/kg) via oral gavage once a day for 28 days, followed by an exhaustive swimming exercise. Swimming times were recorded for each animal after which malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were determined.Results: Exhaustive swimming times were significantly prolonged in all AAPs-treated animals as compared with controls. In all treatment groups, serum and muscle MDA levels were significantly lower than those in the C group, whereas in the MA- and HA-treated groups, a decrease was also seen for liver MDA levels. Furthermore, the concentration of 8-OHdG was significantly reduced in serum, liver, and muscle in all AAPs-treated animals. In contrast, all AAPs treatment groups exhibited significantly higher SOD activity in serum, liver, and muscle. Serum and liver GPx activity was also significantly increased in all animals receiving AAPs treatment, with MA- and HA-treated mice exhibiting an additional augmented GPx activity in muscle. Serum and liver catalase activities in the MA and HAtreated groups, and catalase activity in muscle in all AAPs treatment cohorts, were significantly higher.Conclusion: Polysaccharides from Auricularia auricula enhance exercise endurance and possess protective effects against exhaustive swimming exercise-induced oxidative stress in mice.Keywords: Exhaustive swimming, Malondialdehyde, 8-Hydroxydeoxyguanosine, Superoxide dismutase, Glutathione peroxidase, Catalase

Effects of Polysaccharides from &lt;i&gt;Radix astragali&lt;/i&gt; on Oxidative Stress Induced by Exhaustive Swimming Exercise in Liver and Muscle of Mice

Polysaccharides, the mainly bioactive ingredient ofRadix Astragali, were evaluated for its effects on the oxidative stress induced by exhaustive swimming exercise of mice. A total of 48 mice were randomly divided into four groups: control group, low-dose polysaccharide fromAstragali radix(RAP) treated group, medium-dose RAP treated group, and high-dose RAP treated group. The control group received only distilled water ig, and the RAP treated groups received different doses of RAP (50, 100, and 200 mg/kg, ig) for 28 days. After the final treatment with RAP, the mice were subjected to swimming to exhaustion and the superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were measured. The data showed that RAP promote increases in the activities of SOD, GPX and CAT in liver and muscle of mice, and the high-dose RAP (200 mg/kg) presented the best effect. These results indicated that RAP possessed protective effects against exercise-induced oxidative stress.

Hydrolyzed protein supplementation improves protein content and peroxidation of skeletal muscle by adjusting the plasma amino acid spectrums in rats after exhaustive swimming exercise: a pilot study

BackgroundThis study was designed to evaluate the effects of hydrolyzed protein supplementation upon skeletal muscle total protein and peroxidation in rats following exhaustive swimming exercise.MethodsTwenty-four rats were randomized to 4 experimental groups (n = 6 per group): control group fed standard diet without exercise (SD), exercise (EX), exercise plus standard diet for 72 hours (EX + SD), and exercise plus standard diet supplemented with hydrolyzed protein (2 g/kg/d) for 72 hours (EX + HP). Immediately following exercise, the EX group was euthanized for collecting plasma and skeletal muscle samples. The EX + SD and EX + HP groups were fed their respective diets for 72 hour still plasma and skeletal muscle collection. Skeletal muscle samples were used to measure levels of total protein (TP), malondialdehyde (MDA), and protein carbonyl (PC). Plasma samples were used to analyze the amino acids spectrum.ResultsCompared with the EX + SD, EX + HP presented the significantly increased TP (P = 0.02) and decreased MDA and PC levels (P = 0.035). MDA was negatively correlated with the methionine levels. Moreover, EX + HP maintained higher levels of plasmaleucine, isoleucine, and methionine than EX + SD, which may be associated with the increased skeletal muscle TP levels observed (P < 0.05).ConclusionsThese results collectively suggest that hydrolyzed protein supplementation can improve skeletal muscle TP and ameliorate peroxidation damage in rats subjected to exhaustive exercise stress, which may be, at least in part, related with the maintenance of plasma leucine, isoleucine, and methionine levels.

Relationships Between Blood Mg2+ and Energy Metabolites/Enzymes After Acute Exhaustive Swimming Exercise in Rats

Magnesium (Mg) plays a central role in neuronal activity, cardiac excitability, neuromuscular transmission, muscular contraction, vasomotor tone, and blood pressure, all of which are significantly related to physical performance. To date, the available data about detection of blood total Mg (tMg; free-ionized, protein-bound, and anion-complex forms) are inconsistent, and there is limited information on blood free-ionized Mg (Mg(2+)) in relation to physical exercise. The aim of this study was to determine the biochemical changes related to energy metabolism after acute exhaustive swimming exercise (AESE) in rats in an attempt to correlate the role of blood Mg(2+) with metabolites/enzymes related to energy production. After AESE, blood Mg(2+), tMg, K(+), partial pressure of carbon dioxide, lactate, total protein (T-PRO), high-density lipoprotein (HDL), creatinine (CRE), blood urea nitrogen (BUN), uric acid (UA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alanine phosphatase (ALP), lactate dehydrogenase (LDH), and creatinine kinase (CK) were significantly increased, whereas pH, partial pressure of oxygen, oxygen saturation, the Mg(2+)/tMg and Ca(2+)/Mg(2+) ratios, HCO3 (-), glucose, triglyceride (TG), and low-density lipoprotein (LDL) were significantly decreased. During AESE, lactate, T-PRO, albumin, AST, ALP, LDH, CK, CRE, BUN, and UA showed significant positive correlations with changes in blood Mg(2+), while glucose, TG, and LDL correlated to Mg(2+) in a negative manner. In conclusion, AESE induced increases in both blood Mg(2+) and tMg, accompanied by changes in blood metabolites and enzymes related to energy metabolism due to increased metabolic demands and mechanical damages.

Protective Role of Polysaccharides from &lt;i&gt;Gynostemma pentaphyllum &lt;/i&gt;Makino Supplementation against Exhaustive Swimming Exercise-Induced Oxidative Stress in Liver and Skeletal Muscle of Mice

The objective of this study was to investigate the protective role of polysaccharide fromGynostemma pentaphyllumMakino (PGP) supplementation against exhaustive swimming exercise-induced oxidative stress. A total of 48 mice were randomly divided into four groups: control, low-dose, medium-dose, and high-dose PGP supplementation groups. The control group received distilled water and the supplementation groups received different doses of PGP (50, 100 and 200 mg/kg body weight) by gavage once a day for 28 consecutive days. After 28 days, the mice performed an exhaustive swimming exercise, and some biochemical parameters related to oxidative stress, including superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and malondialdehyde (MDA), were measured. The results showed that PGP supplementation could increase SOD, GPx and CAT contents, as well as decrease MDA contents in the liver and skeletal muscle of mice, which suggests that PGP supplementation has a protective role against exhaustive swimming exercise-induced oxidative stress.

Effect of exercise intensity on cerebrospinal fluid interleukin-6 concentration during recovery from exhaustive exercise in rats

The purpose of this study was to investigate the possible role of moderate and strenuous swimming training on plasma and cerebrospinal fluid (CSF) IL-6 (interleukin-6) levels during recovery from exhaustive exercise in rats. Wistar rats were divided into three groups: sedentary control (C), moderately trained (MT) and strenuously trained (ST). MT rats underwent swimming exercise for one hour/day and 5 days/week for 8 weeks. Animals in the ST group began swimming with 1 h/day and swimming duration was progressively increased by 30 min/wk, reaching 2.5 h/day by week 4 and stayed constant for an additional 4 weeks. After all animals underwent an acute exhaustive swimming exercise, animals were divided into 3 groups, and decapitated immediately, 24 and 48 hours after exhaustion to obtain tissue samples. Muscle citrate synthase activity, plasma and CSF IL-6 levels were determined. The citrate synthase activity was found to be higher in MT and ST groups compared to the C group. Although plasma IL-6 levels were found unaltered among all groups, the CSF IL-6 concentration was found to be increased 24 hours after exhaustive exercise of the ST group. We conclude that exercise training intensity is an important factor determining cerebrospinal IL-6 concentration after exhaustive exercise.