Markers Of Muscle Injury Research Articles

Efficacy of combined ultrasound and microbubble treatment for thrombolysis for rescuing ischemic tissues in rats at different time after thrombosis

To explore the relationship between the time after thrombosis and the efficacy of combined ultrasound and microbubble treatment for rescuing the ischemic tissues. Rat models of thrombosis in the right common iliac artery were established and received combined ultrasound and microbubble treatment at 3, 6 and 12 h after thrombosis. The recanalization rate of the right common iliac artery was assessed using both 2-dimensional and Doppler ultrasound. The plateau acoustic intensity (AI) was quantified for estimating the skeletal microvascular blood volume, and skeletal muscle injury markers including myoglobin (Mb) and creatinine kinase (CK) were measured using ELISA. Postmortem TUNEL staining was used to detect the apoptotic rate of skeletal muscle cells in the hind limb of the rats. Compared with those in 3 h group, the recanalization rate and AI were significantly lower, and the levels of Mb and CK and the apoptotic rate of the skeletal muscle cells were significantly higher in both 6 h group and 12 h group (P < 0.05). Compared with those in 6 h group, the rats receiving treatment at 12 h after thrombosis showed significantly lowered AI and increased Mb, CK and apoptotic rate of the skeletal muscle cells (P < 0.05). The efficacy of combined ultrasound and microbubble treatment for rescuing ischemic tissues tends to be attenuated as the time after thrombosis prolongs in rats.

The effects of full marathon on hemodynamics related to cardiac electrophysiology of marathon amateurs

Objective To observe and assess the effects of full marathon on hemodynamics and cardiac electrophysiology of marathon amateurs without adverse event after the race. Methods Fifty-one subjects were included in the final analysis of the study, blood pressure, heart rate, body surface electrocardiogram (ECG) of all subjects under static status before the race and within (15-30) min after the race were detected, and sufficient amounts of the peripheral blood and the radial arterial blood specimens of all subjects under static status before the race and within (15-30) min after the race were collected instantly. The peripheral blood was used for measuring markers of muscle injury and NT-proBNP, and the radial arterial blood was taken for blood gas analysis. The QTc interval, QRS, PR interval, and QTd interval were recorded from the 12-lead ECG report. Results Compared with those under static status before the race, the systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and heart rate of all the subjects within (15-30) min after the race were significantly higher (P<0.05). When the markers of striated muscle injury were compared before and after the competition, levels of CK, cTNI, LDH, and myoglobin after the race were significantly increased compared with them under static status before the race (P <0.05), and the level of NT-proBNP after the race was also significantly increased compared with it before the race (P<0.05). When blood gas analysis before the race was compared with that after the race, the PH values after race were significantly lower than it before race (P<0.05). The level of lactic acid after the race was significantly higher than it before race (P<0.05). After the race, the levels of PCO2, SBE and HCO3- decreased significantly compared with those before race (P<0.05), and the QTc and QTd intervals after the race increased significantly compared with those before the race, however, the QTc interval and QTd interval for all subjects before and after the competition were within the normal range. Conclusions Full marathon significantly affect the myocardial electrophysiological markers of healthy amateur athletes without chronic diseases, but those markers fluctuate within the normal range. Key words: Full marathon; Hemodynamics; Cardiac electrophysiology; Cardiac function; Striated muscle injury; Healthy amateurs athletes; QTc interval; QTd interval

Effect of Core Temperature during Exercise on Markers of Muscle Injury and Oxidative Stress

Exercise of sufficient intensity carried out at room temperature significantly increases core temperature (Tc) in rats. In this study we tested the hypothesis that preventing the exercise‐induced rise in Tc will decrease markers of skeletal muscle injury and oxidative stress that are associated with prolonged exercise bouts. Following one week of familiarization to a motor driven treadmill in a 23°C room, male, 10‐wk‐old Sprague‐Dawley rats were assigned to a sedentary (S) group (n = 15) or to groups that ran on a treadmill for 90 min at a speed of 20 m/min up a 6° grade in either a 23°C room (23R) (n = 10) or an 8°C room (8R) (n = 9). Tc was monitored via telemetry. Blood was collected from the tail vein at rest or immediately post exercise followed by removal of gastrocnemius and plantaris muscles. An aliquot of blood was immediately acidified to stabilize oxidized (GSSG) and reduced (GSH) glutathione and these markers of oxidative stress were subsequently measured by HPLC with electrochemical detection. Serum was prepared in the remainder and used to measure lactate dehydrogenase activity (LDH) as an indicator of muscle injury. Glycogen content and additional markers of oxidative stress (TBARS and aconitase activity) were measured in skeletal muscles. Tc was unchanged from rest in 8R and increased 2.5°C to 40.5±0.2°C in 23R (P&lt;0.05). Compared to S, serum LDH in 23R increased 105% (P&lt;0.05) but did not change in 8R (P&gt;0.05). Similarly, blood GSSG content and GSSG/total glutathione increased 132% and 180%, respectively, in 23R (P&lt;0.05) and did not change in 8R compared to S. TBARS and aconitase activity in muscles were not different among groups (P&gt;0.05). Gastrocnemius glycogen was depleted approximately 40% in both 23R and 8R compared to S (P&lt;0.05). We conclude that elevated Tc plays a major role in aerobic exercise‐induced increases in oxidative stress and muscle injury.Support or Funding InformationSupported by UNC‐Greensboro Safrit Research Measurement Fund

Effects of a Novel Dietary Supplement on Indices of Muscle Injury and Articular GAG Release in Horses

This study determined the ability of an oral nutraceutical supplement to attenuate the oxidative stress and inflammation that occurs in muscles and joints with repeated bouts of high-intensity exercise in horses. The supplement, fed daily, was comprised of whole dried mushrooms, golden flaxseed, omega-3 fatty acids, plant-based enzymes, a melon-concentrate powder, and Saccharomyces cerevisiae boulardii. Ten horses participated in a partial cross-over design, with 7 horses completing the Control trial and 7 horses completing the supplement trial. Blood and synovial fluid samples (from the intercarpal joint) were taken before, and at 1 and 24 hours after a standardized, repeated high-intensity exercise test that was performed before supplementation and on the 22nd day of supplementation. At the end of the supplement trial exercise resulted in reduced concentrations of plasma markers of oxidative stress (decreased thiobarbituric acid reactive substances, with increased total antioxidant status and increased superoxide dismutase activity); there was no effect on plasma markers of muscle injury (creatine, creatine kinase, and aspartate aminotransferase) or inflammation (PGE2, nitric oxide). Within synovial fluid, there was a tendency for increased superoxide dismutase activity, and decreased concentration of glycosaminoglycans. It is concluded that the supplement, when fed to horses as part of the normal diet for 23 days, was associated with reduced concentrations of markers of oxidative stress and inflammation in muscle and synovial fluid.

Aerobic Conditioning Might Protect Against Liver and Muscle Injury Caused by Short-Term Military Training

This study aimed to compare the biochemical markers of muscle and liver injury and total antioxidant capacity in army cadets after a traditional army physical training program and to correlate these effects with aerobic conditioning. Male army cadets (n = 87; age, 20 ± 2 years) were evaluated 12 hours before the start of training (T0), 12 hours after a 30-km march (T1), and 48 hours after military training (T2). Creatine kinase (CK), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) serum levels were measured using an autoanalyzer. Total antioxidant capacity was determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (Sc%). Seventy-four percent of army cadets were classified as having excellent aerobic conditioning (53.9 ± 3.0 ml · kg(-) · min(-1) predicted VO2max from the Cooper test). The median serum concentration of all enzymes increased 12 hours after marching (T1: CK 675%; ALT 59%; AST 336%; AST/ALT ratio 85%; p = 0.001) and 48 hours after the end of training (T2: CK 878%; ALT 256%; AST 418%; AST/ALT ratio 180%; p = 0.001). Sc% was higher in T2 (31.1 ± 9.8%; p = 0.01) than in T0 (3.4% change). Maximal oxygen consumption (ml · kg(-1) · min(-1)) correlated negatively with CK (r = -0.25; p = 0.009) and ALT (r = -0.21; p = 0.03) serum levels, and positively with the change in Sc% (r = 0.22; p = 0.04) at T2. The results indicate that intense military training can cause liver and muscle injury and that aerobic conditioning can be considered as a protective factor for these injuries.

Diagnostic impact of serum myoglobin and human heart-type fatty acid binding protein in patients with acute myocardial infarction

Objective: The aim of the study was to assess the value of the serum concentrations of myoglobin and human heart-type fatty acid binding protein (H-FABP) in the early detection of acute myocardial infarction (AMI). Background: Myoglobin and H-FABP are useful as biochemical markers of muscle injury. We conducted this investigation to detect whether both markers and their ratio were useful in the early detection of AMI. Patients and methods: This study included 21 patients with AMI, 20 patients with skeletal muscle injury, and 10 normal healthy individuals. Their blood samples were obtained (within 6 h of onset of chest pain in AMI patients), and serum concentrations of creatinine, aspartate aminotransferase, H-FABP, myoglobin, cardiac troponin I, and creatine kinase-MB (CK-MB) were determined. Results: It was found that H-FABP has higher sensitivity and predictive accuracy compared with myoglobin in the early detection of AMI: the sensitivity of H-FABP was 95% and that of myoglobin was 81%, and the sensitivity of their ratio was 90%. H-FABP is a more sensitive marker, but in our study its specificity was 90%, which was lower than that of myoglobin (99%) for the detection of AMI within 6 h after the onset of chest pain. Also, our study showed that myoglobin and H-FABP were directly proportional to troponin and CK-MB, in which there is significant positive correlation. Conclusion: The diagnostic sensitivity of H-FABP is high, above that of myoglobin in patients presenting within 6 h of chest pain. H-FABP is a sensitive and specific marker for the early diagnosis of AMI. The lower specificity of H-FABP makes troponin and CK-MB superior for the diagnosis of AMI.

Winning the war against ICU-acquired weakness: new innovations in nutrition and exercise physiology

Over the last 10 years we have significantly reduced hospital mortality from sepsis and critical illness. However, the evidence reveals that over the same period we have tripled the number of patients being sent to rehabilitation settings. Further, given that as many as half of the deaths in the first year following ICU admission occur post ICU discharge, it is unclear how many of these patients ever returned home. For those who do survive, the latest data indicate that 50-70% of ICU "survivors" will suffer cognitive impairment and 60-80% of "survivors" will suffer functional impairment or ICU-acquired weakness (ICU-AW). These observations demand that we as intensive care providers ask the following questions: "Are we creating survivors ... or are we creating victims?" and "Do we accomplish 'Pyrrhic Victories' in the ICU?" Interventions to address ICU-AW must have a renewed focus on optimal nutrition, anabolic/anticatabolic strategies, and in the future employ the personalized muscle and exercise evaluation techniques utilized by elite athletes to optimize performance. Specifically, strategies must include optimal protein delivery (1.2-2.0 g/kg/day), as an athlete would routinely employ. However, as is clear in elite sports performance, optimal nutrition is fundamental but alone is often not enough. We know burn patients can remain catabolic for 2 years post burn; thus, anticatabolic agents (i.e., beta-blockers) and anabolic agents (i.e., oxandrolone) will probably also be essential. In the near future, evaluation techniques such as assessing lean body mass at the bedside using ultrasound to determine nutritional status and ultrasound-measured muscle glycogen as a marker of muscle injury and recovery could be utilized to help find the transition from the acute phase of critical illness to the recovery phase. Finally, exercise physiology testing that evaluates muscle substrate utilization during exercise can be used to diagnose muscle mitochondrial dysfunction and to guide a personalized ideal heart rate, assisting in recovery of muscle mitochondrial function and functional endurance post ICU. In the end, future ICU-AW research must focus on using a combination of modern performance-enhancing nutrition, anticatabolic/anabolic interventions, and muscle/exercise testing so we can begin to create more "survivors" and fewer victims post ICU care.

Effect of the Muscular Strength Exercise and Massage on Muscle Injury Marker and IGF-1

This experiment is to identify the effect of aid combined with strength exercise and massage affecting muscle injury marker and insulin-like growth factor: IGF-1. Therefore, there were Experimental Group (EG) and Control Group (CG) to identify the effect of the experimental aid. Each aided for 60 minutes, 40 minutes of strength exercise and 20 minutes of massage program, total 24 strength exercises, 3 times a week, for 8 weeks. Through this process we could see there is interactive effect on ammonia, phosphorus, creatine kinase, and lactate dehydrogenase, which are muscle injury markers. There is also interactive effect on IGF-1, which is insulin-like growth factor. As a result, aid combined with strength exercise and massage has a positive effect on muscle injury marker and IGF-1.

Zgodnje prednosti manj invazivne transforaminalne zatrditve ledvene hrbtenice v primerjavi s klasično odprto metodo

AbstractBackgroundLumbar interbody fusion is a standard operative procedure in orthopedic spine surgery. Morphological and functional changes in the multifidus muscle after an open procedure have led to the development of a minimally invasive technique, after which no such muscle changes were observed. MethodsSixty-four patients, with clinical and radiological criteria for one-level transforaminal lumbar interbody fusion were enrolled in our prospective randomized study between December 2011 and March 2014. They were randomized into two groups: open approach (33 patients) vs. minimally invasive approach (31 patients); one patient was excluded from each group due to postoperative complications. Independent samples T-test was used to compare average values of increase in creatin kinase (CK), which is an enzymatic marker of muscle injury, average surgical time, loss of blood during and after surgery, back pain according to the Visual Analogue Scale (VAS) and day of discharge from the hospital. ResultsStatistically important (P&lt; 0.001) lower blood loss (188 ml vs. 527 ml total), less CK increase (15 ukat/L vs. 29 ukat/L), lower VAS score after surgery (7.3 vs. 8.7) and earlier discharge from the hospital (3.5 days vs. 5.2 days) were observed in the minimally invasive transforaminal lumbar interbody fusion group. No significant difference in average surgical time was recorded. Conclusions Our results suggest, that minimally invasive transforaminal lumbar interbody fusion causes is associated with less muscle damage, lower blood loss, less post surgical pain and faster early rehabilitation, which is in accordance with previous studies.

Potential ergogenic activity of grape juice in runners.

Recent studies have indicated that certain food products have ergogenic potential similar to that of sports supplements. The present study aimed to investigate the potential ergogenic effect of integral purple grape juice on the performance of recreational runners. Twenty-eight volunteers of both sexes (age, 39.8 ± 8.5 years; peak oxygen consumption, 43.2 ± 8.5 mL/(kg·min)) were randomized into either a group that received grape juice (grape juice group (GJG), n = 15; 10 mL/(kg·min) for 28 days) or a group that received an isocaloric, isoglycemic, and isovolumetric control beverage (control group (CG), n = 13). A time-to-exhaustion exercise test, anaerobic threshold test, and aerobic capacity test were performed, together with assessments of markers of oxidative stress, inflammation, immune response, and muscle injury, performed at baseline and 48 h after the supplementation protocol. The GJG showed a significant increase (15.3%) in running time-to-exhaustion (p = 0.002) without significant improvements in either anaerobic threshold (3.6%; p = 0.511) or aerobic capacity (2.2%; p = 0.605). In addition, GJG exhibited significant increases in total antioxidant capacity (38.7%; p = 0.009), vitamin A (11.8%; p = 0.016), and uric acid (28.2%; p = 0.005), whereas α-1-acid glycoprotein significantly decreased (20.2%; p = 0.006) and high-sensitivity C-reactive protein levels remained unchanged. In contrast, no significant changes occurred in any of these variables in the CG. In conclusion, supplementation with purple grape juice shows an ergogenic effect in recreational runners by promoting increased time-to-exhaustion, accompanied by increased antioxidant activity and a possible reduction in inflammatory markers.

Temporal specificity of training: intra-day effects on biochemical responses and Olympic-Weightlifting performances

The aim of this study was to investigate the performance of an Olympic-Weightlifting session training at three times of the day on the performance related to biochemical responses. Nine weightlifters (21 ± 0.5 years) performed, in randomised order, on three Olympic-Weightlifting training (snatch, clean and jerk) sessions (08:00 a.m., 02:00 p. m., 06:00 p. m.). Blood samples were collected: before, 3 min and 48 h after each training session. Haematological parameters and markers of muscle injury were assessed. Resting oral temperature and rating of perceived exertion (RPE) were also assessed during each session. ANOVA showed that the performance was better (P < 0.001) at 02:00 p. m. with a less RPE (P < 0.01) compared to the morning and the evening sessions while there was higher (P < 0.05) oral temperature at 06:00 p. m. versus 08:00 a.m. and 02:00 p. m. Muscle damage changed immediately (without significant effect after 48 h) after the training sessions with lower values ​​in the evening compared to the morning. In conclusion, the afternoon training is more effective than morning or evening sessions for weightlifters. Therefore, coaches and weightlifters should be advised to schedule their training session in the afternoon hour.

The Assessment of Effects of Noninvasive Mechanical Ventilation Application on Markers of Muscle Injury and Ischemia

The noninvasive mechanical ventilation (NIMV) is widely used for the treatment of the patients’ chronic obstructive pulmonary disease (COPD) and respiratory failure. noninvasive mechanical ventilationis effective in increasing the ventilation of the lungs and decreasing the work of the heart on the left ventricle and the consumption of the oxygen. In spite of the positive effects of the noninvasive mechanical ventilationtreatment, an increase of cardiac damage is seen in the patients . The aim of this study is to search certain ischemia markers in order to assess and measure the impact of this treatment on the striated muscle and the cardiac muscle of the patients who have been tied to the noninvasive mechanical ventilator, due to their suffering from the difficulty of breathing. With this objective, 64 patients with the diagnosis of COPD are included in this research, and they are divided into two groups. Group I (control group, n=31) consists of the patients who are suffering from mild respiratory failure and not connected to the ventilator. The patients with the severe respiratory failure, prior to their being tied to the ventilator, constitute Group II (before ventilation (vö)) (n=33), after their having been connected to the ventilator (3rd day), are the members of Group II (after ventilation (vs)) (n=33). The levels of blood pH, pO2 and pCO2, serum troponin, myoglobin, creatine kinase (CK), CKMB, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), albumin, and the ischemia modified albumin (IMA) have been measured in the patients. The level of serum troponin has been observed higher in prior to NIMV (Group II (vö)) than control group (Group I). Likewise, it has been noted significant increase in group after NIMV (Group II (vs)). Serum AST and IMA has also been seen a significant increase in group after NIMV (Group II (after)) as compared to the control group (Group I). There was no significant difference among the groups at the levels of serum myoglobin, CK-MB, ALT, CK, LDH (p>0.05). It was concluded that, depending on the severity of respiratory failure, that are markers of ischemia, serum troponin, AST and IMA levels increased, NIMV application contributed to this increase is limited and cardiac function more careful should be followed during the non-invasive mechanical ventilation application.

Does Ramadan fasting affect the diurnal variations in metabolic responses and total antioxidant capacity during exercise in young soccer players?

The aim of this study was to investigate the effects of Ramadan fasting and time-of-day on biochemical responses to an intermittent exercise [Yo–Yo test level 1, (YYIRT)]. Twenty male soccer players (17.52 ± 0.2 years, 177.4 ± 2.9 cm) completed the YYIRT at 0700 and 1700 hours on three occasions: 1 week before Ramadan (BR), the second week of Ramadan (SWRR2), and the fourth week of Ramadan (ERR4). The total distance covered during the YYIRT (TD) was recorded. Moreover, blood samples were obtained before and after the YYIRT for biochemical measurements. TD was higher BR than during Ramadan in the evening (P < 0.05), but not in the morning. However, there was no significant difference between BR and Ramadan in the morning. While post-exercise values of blood lactate (Lac), glucose (GLC), and markers of muscle injury were greater higher in the evening, resting total antioxidant status (TAS) and uric acid (UA) levels were higher in the morning as compared with the evening BR. These diurnal variations were hidden during Ramadan due to a significant decrease in Lac (P < 0.01), GLC (P < 0.05) and cellular damage (P < 0.05) and an increase in TAS and UA (P < 0.05) values in the evening. No significant difference in biochemical responses was observed in the morning during SWRR2 and ERR4 as compared with BR. In summary, the present study indicates that YYIRT performance was affected by Ramadan fasting only in the evening in young soccer players. The modified diurnal pattern of biochemical responses could explain this performance decrement.

Changes in Oxidative Stress Markers and Biological Markers of Muscle Injury with Aging at Rest and in Response to an Exhaustive Exercise

PurposeThe aim of this study was to evaluate whether oxidative stress markers and biomarkers of muscle injury would be affected by aging at rest and in response to an incremental exhaustive exercise.MethodsFifteen young (20.3±2.8 years) and fifteen older adults (65.1±3.5 years) performed an incremental cycle ergometer test to exhaustion. Before and after exercise, oxidative stress [superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GR), ascorbic acid, α-Tocopherol, malondialdehyde (MDA)] and muscle injury [creatine kinase (CK), lactate deshydrogenase (LDH)] biomarkers were assessed.ResultsAt rest, there was no difference in oxidative stress markers and LDH level between the groups, however CK was significantly higher in the young group than the elderly group (p<0.05). During recovery, in comparison with resting values, a significant increase in SOD (1092±145.9 vs. 1243±98 U/g Hb), GPX (67.4±12.7 vs. 79.2±15.6 U/g Hb) and GR (6.5±0.9 vs. 7.7±0.5 U/g Hb) activities were observed only in the young group (p<0.05). MDA has increased only in the older group (0.54±0.2 vs. 0.79±0.2 µmol/l) (p<0.01). CK increased in both groups (young group: 122.5±22.2 vs. 161.9±18.7 UI/l; older group: 88.8±34.1 vs. 111.1±25.9 UI/l) (p<0.01), however LDH has increased only in the young group (400.5±22.2 vs. 485±18.7 UI/l) (p<0.01) without alteration in the older group (382.8±34.1 vs. 418.5±25.9 UI/l).ConclusionsThese findings indicate that aging is associated with a decrease in antioxidant efficiency and an increase in oxidative stress damage. Furthermore, older adults would not more susceptible to exercise-induced muscle injury than young people.

Skeletal muscle atrophy in R6/2 mice - altered circulating skeletal muscle markers and gene expression profile changes.

In addition to classical neurological symptoms, Huntington's disease (HD) is complicated by peripheral pathology, including progressive skeletal muscle wasting, and common skeletal muscle gene expression changes have been shown in HD mice and human HD. To highlight possible mechanisms underlying muscle wasting in HD, we examined gene expression in pathways governing skeletal muscle contractility, skeletal myogenesis, skeletal muscle wasting, apoptosis and the NFκB signaling pathway in two HD mouse models (the transgenic R6/2 and full-length knock-in Q175). In addition, we assessed circulating markers that increase in response to skeletal muscle injury, skeletal Troponin I (sTnI), fatty acid binding protein 3 (FABP3), and Myosin light chain 3 (Myl3). We measured gene expression in muscle tissue as well as in cultured primary myocytes using qPCR. Concentrations of cytokines and muscle proteins were obtained using multiplex ELISA. Circulating markers of muscle injury (sTnI, FABP3, and Myl3) were significantly increased in mouse serum. In skeletal muscle, we observed reduced gene expression of components involved in muscle contractility, with pronounced downregulation of Acta1, Myh2 and Tnni2, among others. Alongside, we found increased expression of caspases (3 and 8) and key elements of the NFκB signaling pathway, p65/RelA, Tradd, and TRAF5. We also found similar gene expression alterations in cultured primary myocytes from R6/2 mice stimulated with TNF-α. Our results indicate that activation of apoptotic and NFκB pathways occur alongside down-regulation of key compartments of the muscle contractility unit in skeletal muscle of HD mice, and muscle atrophy could possibly be a source of circulating disease progression markers.

Acute renal failure: A fatal complication following multiple hornet stings

Hornet (wasp) stings are common worldwide. Most of the time they produce non fatal local allergic reactions, but sometimes can be fatal when mass stinging causes multisystem involvement We report a case of acute renal failure (ARF) following multiple hornet stings. A 28 year male presented with pain and swelling of the body following multiple hornet stings. After 3 days, he developed progressive decrease in urine output with dark colored urine. Physical examination revealed oedematous swelling mainly on exposed parts. On investigating, progressive elevations in renal function test was found. The markers of muscle injury were grossly elevated and liver enzymes were also deranged. These findings suggest multisystem involvement predominantly ARF secondary to rhabdomyolysis. After eight sessions of hemodialysis the patient improved completely. Timely intervention of multiple hornet stings causing ARF with multiorgan involvement by hemodialysis prevents mortality as well as other complications.

Surface Electromyography Assessments of the Vastus medialis and Rectus femoris Muscles and Creatine Kinase after Eccentric Contraction Following Glutamine Supplementation.

L-glutamine is the most abundant amino acid found in human muscle and plays an important role in protein synthesis and can reduce the levels of inflammation biomarkers and creatine kinase (CK) after training sessions. Delayed onset muscle soreness (DOMS) develops after intense exercise and is associated with an inflammatory response. The purpose of this study was to investigate the effect of glutamine supplementation on surface electromyography activity of the vastus medialis muscle (VMM) and rectus femoris muscle (RFM) and levels of creatine kinase after an eccentric contraction. SEVENTEEN HEALTHY MEN (AGE: 22.35±2.27yr; body mass: 69.91± 9.78kg; height: 177.08±4.32cm) were randomly assigned to experimental (n=9) and control groups (n=8) in a double-blind manner. In both groups, subjects were given L-glutamine supplementation (0.1g.kg(-1)) or placebo three times a week for 4 weeks. Median frequency (MDF) and mean power frequency (MPF) for VMM and RFM muscles and also CK measurements were performed before, 24h and 48 h after a resistance training session. The resistance training included 6 sets of eccentric leg extensions to exhaustion with 75% of 1RM. There was no significant difference between groups for MDF or MPF in VMM and RFM. The difference of CK level between the groups was also not significant. The results of this study indicate that glutamine supplementation has no positive effect on muscle injury markers after a resistance training session.

Effect of L-glutamine supplementation on electromyographic activity of the quadriceps muscle injured by eccentric exercise.

The purpose of the present study was to examine the effects of L-glutamine on electromyographic (EMG) activity of the quadriceps muscle injured by eccentric exercise (EE). Seventeen healthy men (age: 22.35±2.27 yr; body mass: 69.91±9.78 kg; height: 177.08±4.32 cm) were randomly and double-blind study with subjects assigned to either an L-glutamine supplementation (n=9) or placebo (n=8) group. The subjects in two groups were asked to take three times during a week for 4 weeks. Each subject was screened for dietary habits before inclusion into the study. Participants performed 6 set to exhaustion eccentric leg extensions at 75% of 1RM and rest intervals were 3 min among sets. Pain Assessment Scale (PAS), EMG activity and range of motion (ROM) measurements were taken before exercise protocol and 24 and 48 hr afterwards. There was no statistically significant difference between groups in perceived muscle soreness (SOR), ROM and EMG activity (P < 0.05). The results indicate that L-glutamine supplementation has no significant effect on muscle injury markers in between groups, although glutamine supplementation attenuated delayed onset muscle soreness (DOMS) effects in sup group.

Effect of HX108-CS supplementation on exercise capacity and lactate accumulation after high-intensity exercise

BackgroundIn the present study, we determined the effects of HX108-CS (mixed extract of Schisandra chinensis and Chaenomeles sinensis) supplementation on lactate accumulation and endurance capacity. Furthermore, we examined CK (creatine kinase), LDH (lactate dehydrogenase) activity to determine whether the HX108-CS affected markers of skeletal muscle injury in vivo and in vitro.MethodsExercise capacity was measured by an exhaustive swimming test using ICR mice divided into four groups; one group received distilled water (DW) (Control group, n = 10), and the other groups received three different dosages of HX108-CS (10, 50 and 100 mg/kg, n = 10 per group) solution in water orally. Then, for the time-dependent measurements of blood lactate, CK, and LDH, Sprague–Dawley rats were divided into two groups; one received DW (Control group, n = 10), and the other group received HX108-CS (100 mg/kg, n = 10) solution in the same way as mice. Before the exercise test, the animals were given either DW or HX108-CS for 2 weeks. High-intensity treadmill exercise was performed for 30 minutes. Blood samples were collected and analyzed during and after exercise. For the in vitro experiment, C2C12 cells were treated with HX108-CS to examine its effect on lactate production, CK, and LDH activity.ResultsBlood lactate concentration was significantly lowered immediately after treadmill exercise in HX108-CS group; however, there were no significant differences in activities of CK and LDH between HX108-CS and control during treadmill exercise and recovery phase. Furthermore, treatment with 100 mg/kg of HX108-CS led to a significant increase in the time to exhaustion in swimming test, and concurrently blood lactate concentration was significantly decreased in 50 and 100 mg/kg treated group. Moreover, our results of in vitro experiment showed that HX108-CS suppressed lactate production, CK, and LDH activity in a dose-dependent manner.ConclusionsThese results suggest that supplementation with HX108-CS may enhance exercise capacity by lowering lactate accumulation. This may in part be related to an amelioration of skeletal muscle injury.

Effect of Short-Term Maximal Exercise on Biochemical Markers of Muscle Damage, Total Antioxidant Status, and Homocysteine Levels in Football Players

Prolonged physical exercise results in transient elevations of biochemical markers of muscular damage. This study examined the effect of short-term maximal exercise on these markers, homocysteine levels (Hcy), and total antioxidant status (TAS) in trained subjects. Eighteen male football players participated in this study. Blood samples were collected 5-min before and 3-min after a 30-s Wingate test. The results indicated that plasma biochemical markers of muscle injury increased significantly after the Wingate test (P<0.05). Moreover, significant increase of white blood Cells and their main subpopulations (i.e. monocytes, neutrophiles, and lymphocytes) (P<0.001) has been observed. Likewise, uric acid, total bilirubin, and TAS increased significantly after exercise (P<0.05). However, Hcy levels were unaffected by the Wingate test (for 3-min post-exercise measurement). Short-term maximal exercise (e.g. 30-s Wingate test) is of sufficient intensity and duration to increase markers of muscle damage, and TAS; but not Hcy levels. Increases in the selected enzymes probably come primarily from muscle damage, rather than liver damage. Moreover, increase of TAS confirms the Wingate test induced oxidative stress.