Effects of electrical stimulation of the lower extremities on postprandial hyperglycemia and arterial stiffness


Effects of acute cycling with electrical muscle stimulation of lower limbs on arterial stiffness

一過性の自転車こぎ運動と下肢への電気刺激の併用が動脈スティフネスに及ぼす影響

Japanese Journal of Physical Fitness and Sports Medicine


Effect of curcumin supplementation on inflammatory status and muscle damage in competitive female soccer players: a placebo-controlled, single-blind, nonrandomized, crossover pilot study


Effects of dietary vitamin D deficiency on markers of skeletal muscle mitochondrial biogenesis and dynamics

We examined the effects of dietary vitamin D deficiency on markers of mitochondrial biogenesis and dynamics in rat soleus muscle. Male Wistar rats were fed a chow with no vitamin D (No-D; 0 IU/kg) or a moderate dose (Mod-D; 2,000 IU/kg) of vitamin D chow for 8 wk. Compared to the Mod-D group, at 8 wk the No-D group showed significantly lower serum 25(OH)D levels. Although vitamin D deficiency had no effect on body composition, the No-D rats showed significantly decreased levels of PGC-1α, a marker of skeletal muscle mitochondrial biogenesis, and DRP1, a marker of skeletal muscle mitochondrial fission. The change in the PGC-1α protein expression and the serum 25(OH)D concentrations were significantly correlated. The change in DRP1 protein expression and the serum 25(OH)D concentrations tended to be correlated. There was no significant between-group difference in markers of mitochondrial fusion (MFN2 and OPA1) and mitophagy (PARKIN) in soleus muscle, and no relationship with serum 25(OH)D concentrations. Collectively our findings suggest that dietary vitamin D deficiency decreased PGC-1α and DRP1 protein expression in rat soleus muscle.

Journal of Nutritional Science and Vitaminology


Eccentric exercise improves myocardial oxygen supply/demand balance with decelerating aortic diastolic pressure decay: the acute and chronic studies

Both eccentric (ECC) and concentric (CON) exercises improve energy expenditure and blood lipid profile. Although ECC exercise has a more beneficial effect on these factors than CON exercise, its benefits on vital organs are still unclear. This study investigated the mode-of-action-dependent effects on myocardial perfusion index. Seventeen healthy men (age: 26 ± 5 years) were randomly enrolled in CON ( = 9) and ECC ( = 8) groups. Transient exercise and regular training (three-day a week for 4-week) included bicep curl comprising 5-set of 10-repetition, each using 75% one-repetition maximum concentric loading. The ECC group performed one-repetition of ECC for 3-s and CON for 1-s, while the CON group performed one-repetition of CON for 3-s and ECC for 1-s. All participants were assessed for subendocardial viability ratio (SEVR, myocardial perfusion index) and aortic diastolic pressure decay. Before study, these were found to be same for both groups. Transient (ΔSEVR: 20.3 ± 13.3%, = 0.01; Δdecay: -0.07 ± 0.02 s, < .001) and regular (ΔSEVR: 18.5 ± 12.8%, = .001; Δdecay: -0.06 ± 0.05 s, = .004) ECC (but not CON) exercises significantly increased SEVR and decelerated decay. Increased SEVR with ECC exercise was associated with decelerated decay (transient ECC: = 0.56, 95% confidence interval [CI] = -0.95 to -0.10, = .03; regular ECC: = 0.53, 95% CI = -0.95 to -0.05, = .04). These findings suggest that ECC exercise improves myocardial perfusion and diastolic pressure contour is involved in physiological mechanisms.


Egg white protein promotes developmental growth in rodent muscle independent of the leucine content

Leucine has unique anabolic properties, serving as a nutrient signal that stimulates muscle protein synthesis. We tested whether the leucine concentration is the only factor determining protein quality for muscle development. We selected 3 dietary proteins: casein (CAS), egg white protein (EWP), and albumin (ALB), representing the leucine concentrations of ∼8.3%, 7.7%, and 6.7% of the total protein (wt:wt), respectively. In the chronic feeding experiment, these proteins were pair-fed to growing male Wistar rats [110-135 g body weight (BW)] for 14 d as a protein source, providing 10% of total energy intake, after which soleus and extensor digitorum longus (EDL) muscles were used to estimate muscle growth. In the acute administration experiment, we injected CAS, ALB, and EWP to rats by oral gavage (0.3 g protein/100 g BW), and after 1 or 3 h EDL muscle was excised for capillary electrophoresis-MS-based metabolomics. In another chronic feeding experiment, rats were pair-fed either CAS or a CAS diet supplemented with arginine to the same level as in the EWP diet for 14 d. At the end of the 14-d feeding, soleus and EDL muscle weight was 20% and 17% higher, respectively, when rats were fed EWP as compared with CAS (P < 0.05). In addition, the 14-d EWP diet increased the expression of p70S6K by 117% compared with CAS (P < 0.05). These results suggest the possibility that some amino acids (excluding leucine), derived from EWP, promote muscle growth. Metabolomics analysis showed that muscle arginine concentration, following acute protein administration, appeared to match muscle growth over the 14-d feeding period. In addition, 14-d arginine supplementation to a CAS diet increased EDL muscle weight by 15% when compared with the plain CAS diet (P < 0.05). EWP promotes rat developmental muscle growth compared with CAS, which can be partly explained by the arginine-rich EWP.


N-aceytyltaurine and acetylcarnitine production for the mito-chondrial acetyl-CoA regulation in skeletal muscles during endurance exercise


Short-term running exercise alters DNA methylation patterns in nNOS and BDNF genes in the mouse hippocampus and reduces anxiety-like behaviors

Running exercise has beneficial effects on brain health. However, the effects of relatively short-term running exercise (STEx) on behavior, and its underlying signaling pathways, are poorly understood. In this study, we evaluated the possibility that the regulation by STEx of brain-derived neurotrophic factor (BDNF) and neuronal nitric oxide synthase (nNOS, encoded by NOS1), which are important molecules for anxiety regulation, might involve mechanisms of epigenetic modification, such as DNA methylation. C57BL/6J male mice were divided into sedentary (SED, n = 12) and STEx (EX, n = 15) groups; STEx was conducted with the mice for a duration of 11 days. STEx reduced anxiety-like behaviors, and STEx reduced Nos1α and increased Bdnf exon I and IV mRNA levels in the hippocampus. Interestingly, behavioral parameters were associated with Bdnf exon I and IV and Nos1α mRNA levels in the ventral, but not dorsal, hippocampal region. However, STEx had no effect on peroxisome proliferator-activated receptor-γ coactivator 1α (Pgc-1α) or fibronectin type III domain-containing 5 (Fndc5) mRNA levels, which are relatively long-term exercise-induced upstream regulators of BDNF. In parallel with gene expression changes, we found, for the first time, that STEx downregulated Bdnf promoter IV and upregulated Nos1 DNA methylation levels in the hippocampus, and these patterns were partially different between the dorsal and ventral regions. These findings suggest that the beneficial effects of running exercise on mood regulation may be controlled by alterations in epigenetic mechanisms, especially in the ventral hippocampus. These effects occur even after a relatively short-term period of exercise.


Effects of Aerobic Exercise before a Task on the Ability to Coordinate Exertion of Force

課題前の有酸素性運動が筋力発揮調整能に及ぼす影響

[Purpose] The purpose of this study was to examine the effects of aerobic exercise before a task on the ability to coordinate exertion of force (ACEF). [Participants and Methods] Ten healthy males and 5 females performed two trials in a random order: 10-minutes cycling at 60%VO2 max (AE), and sitting without exercise (CON). The ACEF effect was evaluated using a continuous visual isometric grip task, and seven different force trials were performed 8 times each, a total of 56 times. [Results] In the AE trial the number of successful grip tasks significantly increased after 1 and 24 hours compared to the pre-test value; however, there were no significant changes in the CON trial. [Conclusion] Aerobic exercise before a task may enhance the promotion and retention of ACEF.

〔目的〕課題前の有酸素性運動が筋力発揮調整能に及ぼす効果について検討した．〔対象と方法〕対象者は，健常成人15名であり，すべての対象者は60%VO2 maxで10分間の自転車こぎ運動(aerobic exercise:AE)条件および安静座位のコントロール(control:CON)条件の2条件をランダムで実施した．筋力発揮調整能テストは，7つの強度をそれぞれ8回，計56回を無作為に実施した．〔結果〕AE条件における筋力発揮調整能の成功数は，実施1時間後および24時間後に実施前と比較して有意に増加した．CON条件では実施前と比較して有意な変化は認められなかった．〔結語〕課題前の有酸素性運動は筋力発揮調整能の促進および保持を向上させる可能性がある．


Regular resistance training favorably affects central artery stiffness response following transient resistance exercise


Sleep quality is associated with central arterial stiffness in postmenopausal women: a cross-sectional pilot study


Stature is negatively associated with increased arterial stiffness after high-intensity bicep curls training in young Japanese men

Reports have indicated that high-intensity resistance training (RT) increases or does not change arterial stiffness. Meanwhile, higher stature has been suggested to have a protective effect on cardiovascular disease and arterial stiffness. Stature could explain the disagreement in the reported effects of RT on arterial stiffness. This study was aimed at investigating whether stature is related to RT-induced change in arterial stiffness. Thirty-six young Japanese men were assigned to the control ( = 15) and training groups ( = 21). RT programme consisted of supervised bicep curls 3 days per week for 4 weeks (5 sets of 10 repetitions at 75% of 1-repetition maximum). Arterial compliance (AC) and β-stiffness index (via combination of ultrasound and carotid pressure waveforms) were measured in all participants. To verify the effect of stature on RT-induced change in arterial stiffness, the training group was divided into tertiles of stature: lower, middle, and higher stature groups (each group, = 7). RT significantly decreased AC and increased β-stiffness index in only the lower stature group (both, < 0.05). Moreover, stature was positively associated with decreased AC and negatively associated with increased β-stiffness index, even after adjusting for confounders including changes in relative strength, pulse pressure, and arterial distension ( < 0.05). The present results suggest that short stature contributes to the increase in arterial stiffness induced by RT in young Japanese men. The present findings suggest that stature should be taken into consideration when designing/engaging in RT programme, due to potential implications for cardiovascular health. Participants were divided into 3 groups according to tertiles of statures, and arterial stiffness of lower stature group (range of stature: 161.0-169.8 cm) increased after resistance training in young Japanese men, but not middle and higher stature group.Stature was negatively associated with the changed arterial stiffness by resistance training.This study suggests that short stature contributes to the elevation in arterial stiffness elicited by resistance training.


Oxidative stress in the blood after full marathon in amateur runner - Assessment using d-ROM and BAP test-

アマチュアランナーにおけるフルマラソン後の血中酸化ストレス評価 -d-ROMおよびBAPテストを用いた検証-


Taurine supplementation enhances endurance capacity by delaying blood glucose decline during prolonged exercise in rats

Taurine enhances physical performance; however, the underlying mechanism remains unclear. This study examined the effect of taurine on the overtime dynamics of blood glucose concentration (BGC) during endurance exercise in rats. Male F344 rats were subjected to transient treadmill exercise until exhaustion following 3 weeks of taurine supplementation or non-supplementation (TAU and CON groups). Every 10 min during exercise, BGC was measured in blood collected through cannulation of the jugular vein. Gluconeogenesis-, lipolysis-, and fatty acid oxidation-related factors in the plasma, liver, and skeletal muscles were also analyzed after 120-min run. Exercise time to exhaustion was significantly longer with taurine supplementation. BGC in the two groups significantly increased by 40 min and gradually and significantly decreased toward the respective exhaustion point. The decline in BGC from the peak at 40 min was significantly slower in the TAU group. The time when the once-increased BGC regressed to the 0-time level was significantly and positively correlated with exercise time until exhaustion. At the 120-min point, where the difference in BGC between the two groups was most significant, plasma free fatty acid concentration and acetyl-carnitine and N-acetyltaurine concentrations in skeletal muscle were significantly higher in the TAU group, whereas glycogen and glucogenic amino acid concentrations and G6Pase activity in the liver were not different between the two groups. Taurine supplementation enhances endurance capacity by delaying the decrease in BGC toward exhaustion through increases of lipolysis in adipose tissues and fatty acid oxidation in skeletal muscles during endurance exercise.


LDH isoenzyme 5 is an index of early onset muscle soreness (EOMS) during prolonged running.

EOMS started to occur at 20 km during a 30 km running task. Our data suggest that LDH isoenzyme 5 is a marker of occurrence in EOMS during prolonged running.

The Journal of Sports Medicine and Physical Fitness


Acute bout of exercise downregulates thioredoxin-interacting protein expression in rat contracting skeletal muscles.

We previously reported that in rat skeletal muscle, disuse (i.e., decreased muscle contractile activity) rapidly increases thioredoxin-interacting protein (TXNIP), which is implicated in the reduced glucose uptake. Accordingly, we sought herein to (a) determine the effect of exercise (i.e., increased muscle contractile activity) on muscle TXNIP protein expression, and (b) elucidate the mechanisms underlying the changes of TXNIP protein expression in response to exercise. Rat epitrochlearis and soleus muscles were dissected out after an acute bout of 3-hr swimming (without weight loading) or 3-hr treadmill running (15% grade at 9m/min). In a separate protocol, the isolated epitrochlearis and soleus muscles were incubated for 3 hr with AMP-dependent protein kinase activator AICAR. Immediately after the cessation of the 3-hr swimming, the TXNIP protein was decreased in epitrochlearis but not in soleus muscle. Conversely, 3-hr treadmill running decreased the TXNIP protein in soleus but not in epitrochlearis muscle. TXNIP protein was decreased concomitantly with reduced postexercise muscle glycogen, showing that a decrease in TXNIP protein expression occurs in muscles that are recruited during exercise. In addition, 3-hr incubation with AICAR decreased TXNIP protein in both isolated epitrochlearis and soleus muscles. Our results suggest that (a) an acute bout of exercise downregulates TXNIP protein expression in rat contracting skeletal muscles, and (b) the reduction in TXNIP protein expression in contracting muscles is probably mediated by AMPK activation, at least in part.


Relationship between early-onset muscle soreness and indirect muscle damage markers and their dynamics after a full marathon.

Muscle soreness peaked and muscle damage markers in the blood showed different dynamics after a full marathon. In other words, this is different from DOMS.


Anxiety-like behaviors and hippocampal nNOS in response to diet-induced obesity combined with exercise.

A high-fat diet (HFD) and overweight status can induce hippocampal dysfunction, leading to depression and anxiety. Exercise has beneficial effects on emotional behaviors. We previously reported that exercise training rescues HFD-induced excess hippocampal neuronal nitric oxide synthase (nNOS) expression, which is a key regulator of anxiety. Here, we investigated anxiety-like behaviors and hippocampal nNOS expression in response to HFD combined with exercise. Mice were assigned to standard diet, HFD, or HFD with exercise groups for 12 weeks. We found that exercise during the final 6 weeks of the HFD regime improved 12 weeks of HFD-induced defecation, accompanied by rescue of excess nNOS expression. However, anxiety indicators in the elevated plus maze were unchanged. These effects were not apparent after only 1 week of exercise. In conclusion, 6 weeks of exercise training reduced HFD-related anxiety according to one of our measures (defecation), and reversed changes in the hippocampal nNOS/NO pathway.


Effects of Taurine Supplementation on Vascular Endothelial Function at Rest and After Resistance Exercise.

High-intensity resistance exercise has been shown to increase arterial stiffness and reduce vascular endothelial function. Taurine supplementation has a favorable effect on maintaining vascular function. We had previously reported that taurine supplementation attenuated increases in resistance exercise-induced arterial stiffness. In the present study, we further investigate the effects of taurine supplementation on vascular endothelial function at rest and after resistance exercise.Twenty-nine healthy men were recruited and randomly assigned to either the placebo supplement group (n=14) or the taurine supplement group (n=15) in a double-blinded manner. Subjects were required to ingest 6g of either a placebo or the taurine supplement for 2weeks prior to and 3days following the exercise. Two weeks after the commencement of supplementation, the subjects were asked to perform 2 sets of 20 repetitive unilateral maximal-effort resistance exercise of the elbow flexors on a Biodex isokinetic dynamometer, with each contraction lasting 3s, with 1 repetition performed every 9s and 4 min rest in between sets. We evaluated the changes in brachial artery flow-mediated dilation (FMD) in the non-exercised arm as an index of vascular endothelial function. Relative and absolute FMDs were measured prior to supplementation, before exercise, and 24, 48, and 96h after exercise.Two weeks of taurine supplementation significantly increased both relative and absolute FMDs. Baseline diameter significantly increased at 96h following the exercise in both groups. However, there was no change in the peak diameter. Consequently, both relative and absolute FMDs were significantly reduced at 96h after the exercise in both groups. Taurine supplementation does not affect resistance exercise-induced reduction in FMD.Two weeks of taurine supplementation (6g/day) significantly increased vascular endothelial function at rest; however, taurine supplementation did not improve resistance exercise-induced reduction in FMD.

Advances in Experimental Medicine and Biology


Effect of BCAA supplement timing on exercise-induced muscle soreness and damage: a pilot placebo-controlled double-blind study.

The present study confirmed that repeated BCAA supplementation before exercise had a more beneficial effect in attenuating DOMS and EIMD induced by eccentric exercise than repeated supplementation after exercise.


Resistance training-induced decreases in central arterial compliance is associated with increases in serum thromboxane B2 concentrations in young men


Effects of resistance training on arterial compliance and plasma endothelin-1 levels in healthy men.

Arterial compliance (AC) is an index of the elasticity of large arteries. Endothelial dysfunction has been reported to result in reduced arterial compliance, which represents increased arterial stiffness. A reduction in AC is elicited by high-intensity resistance training, however the mechanisms are obscure. Because a single bout of resistance exercise causes a transient increase in circulating plasma endothelin-1 in humans, some vasoconstrictors may play a role in the mechanisms. The present study aimed to investigate whether resistance training-induced decrease in AC is associated with changes in circulating vasoconstrictors levels in young men. Young sedentary men were assigned to control (n=5) or training (n=9) groups. The training group performed four-week high-intensity resistance training (weight training exercise; three sessions/week). We measured AC and plasma levels of endothelin-1, angiotensin II, and norepinephrine before and after intervention. Resistance training significantly decreased AC, whereas the changes in plasma levels of neither endothelin-1, nor angiotensin II, nor norepinephrine were significantly different between the control and the training groups. Moreover, we found no significant correlations between changes in circulating plasma levels (endothelin-1, angiotensin II, and norepinephrine) and in the AC. Despite of no alteration of the resting circulating plasma levels (endothelin-1, etc.), we cannot exclude a possibility that the tissue/local concentrations of vasoconstrictors (endothelin-1, etc.) around the vessels might be increased and also involved in a reduction of AC in the training group. Taken together, the present results suggest that circulating vasoconstrictors (endothelin-1, etc.) in plasma are not involved in a reduction in AC by the resistance training.

Physiological Research / Academia Scientiarum Bohemoslovaca


Hemodynamic response to unilateral resistance exercise with lactotripeptides

Gazzetta Medica Italiana Archivio per le Scienze Mediche


Immobilization rapidly induces thioredoxin-interacting protein gene expression together with insulin resistance in rat skeletal muscle.

Acute short duration of disuse induces the development of insulin resistance for glucose uptake in rodent skeletal muscle. Because thioredoxin-interacting protein (TXNIP) has been implicated in the downregulation of insulin signaling and glucose uptake, we examined the possibility that muscle disuse rapidly induces insulin resistance via increased TXNIP mRNA and protein expression. Male Wistar rats were subjected to unilateral 6-h hindlimb immobilization by plaster cast. At the end of this period, the soleus muscles from both immobilized and contralateral nonimmobilized hindlimbs were excised and examined. The 6-h immobilization resulted in an increase in TXNIP mRNA and protein expressions together with a decrease in insulin-stimulated 2-deoxyglucose uptake in the rat soleus muscle. Additionally, in the rats euthanized 6 h after the plaster cast removal, TXNIP protein expression and insulin-stimulated glucose uptake in the immobilized muscle had both been restored to a normal level. Various interventions (pretreatment with transcription inhibitor actinomycin D or AMP-dependent protein kinase activator 5-aminoimidazole-4-carboxamide ribonucleotide) also suppressed the increase in TXNIP protein expression in 6-h-immobilized muscle together with partial prevention of insulin resistance for glucose uptake. These results suggested the possibility that increased TXNIP protein expression in immobilized rat soleus muscles was associated with the rapid induction of insulin resistance for glucose uptake in that tissue. NEW & NOTEWORTHY The cellular mechanism by which disuse rapidly induces muscle insulin resistance for glucose uptake remains to be identified. Using a rat hindlimb immobilization model, our findings suggest the possibility that transcriptional upregulation of thioredoxin-interacting protein is associated with the immobilization-induced rapid development of insulin resistance in skeletal muscle.


Lactotripeptides Supplementations Alleviate the Decrease in Maximal Isometric Force After High-Intensity Eccentric Exercise: A Randomized, Placebo-Controlled, Double-Blind Clinical Trial.

The present results suggest that lactotripeptides supplementation alleviates the decrease in the maximal isometric force via an increase in brachial arterial diameter after ECC.

American Journal of Physical Medicine & Rehabilitation


Aerobic exercise training enhances cerebrovascular pulsatility response to acute aerobic exercise in older adults.

The brain's low resistance ensures a robust blood flow throughout systole and diastole and is susceptible to flow pulsatility. Increased cerebral pulsatility contributes to the progression of cerebrovascular disease. Although aerobic exercise affects vascular function, little is known about the effect of exercise on the cerebral pulsatility index in older adults. The aim of this study was to investigate the effect of exercise training on the post-exercise cerebral pulsatility response in older adults. Ten healthy older adults participated in a 12-week exercise training intervention. Before and after the intervention, we measured the pulsatility index of the middle cerebral artery by means of transcranial Doppler method at baseline and following a cycling exercise bout performed at an intensity corresponding to the ventilatory threshold. Before exercise training, there was no significant change in the cerebral pulsatility response to an acute bout of cycling exercise. However, after the intervention, cerebral pulsatility decreased significantly following 30 min of an acute cycling exercise (P < 0.05). This study demonstrated that cerebral pulsatility index did not change following an acute bout of cycling exercise at an intensity corresponding to ventilatory threshold, but that, after 12 weeks of exercise training, cerebral pulsatility index was reduced at 30 min after a single bout of cycling exercise. These results suggest that long-term aerobic exercise training may enhance the post-exercise reduction in pulsatility index in older adults.


分岐鎖アミノ酸(BCAA)摂取がマラソン後の血清C反応性タンパク質濃度ならびに血漿グルタミン濃度に及ぼす効果


Resistance training-induced decrease in central arterial compliance is associated with decreased subendocardial viability ratio in healthy young men.

High-intensity resistance training decreases central arterial compliance (CAC). Subendocardial viability ratio (SEVR) is a useful tool that reflects the balance between coronary perfusion and left ventricular afterload. Animal studies have demonstrated that decreased CAC is associated with SEVR deterioration. Therefore, resistance training-induced decrease in CAC may be associated with changes in SEVR. The objective of the present study was to investigate the association between SEVR and CAC using both cross-sectional and longitudinal (i.e., resistance training) study designs. To achieve this, we first conducted a cross-sectional study to investigate the association between SEVR and CAC in 89 young men. Thereafter, a longitudinal study was performed to examine the effects of resistance training on SEVR and CAC in young men. A total of 28 young men were divided into 2 groups: control (n = 13) and training (n = 15). In the training group, subjects underwent supervised resistance training for 4 weeks (5 sets of 10 repetitions at 75% of 1-repetition maximum, 3 times/week). CAC and SEVR were then measured in all subjects. In the cross-sectional study, SEVR was significantly positively correlated with CAC, whereas resistance training significantly decreased both SEVR and CAC. Moreover, training-induced changes in CAC were significantly correlated with changes in SEVR. Thus, these results suggest that resistance training-induced decrease in CAC is associated with decreased SEVR in young men.

Applied Physiology, Nutrition, and Metabolism


Effect of habitual exercise on urinary liver-type fatty acid-binding protein levels in middle-aged and older adults.

The purpose of this study was to examine the effect of habitual exercise on urinary liver-type fatty acid-binding protein (L-FABP), which can reflect the degree of various stresses on renal proximal tubule related to the progression of renal disease, in middle-aged and older adults. Cross-sectional and interventional approaches were used to comprehensively achieve this purpose. In the cross-sectional study, we investigated the relationship between physical activity levels and urinary L-FABP levels in 130 middle-aged and older adults. In the interventional study, subjects (n=31) were divided into two groups: exercise (n=19) and control group (n=12), whereby we examined the effects of 12-week aerobic exercise training on urinary L-FABP levels. The cross-sectional study showed that the urinary L-FABP levels were significantly lower in the higher physical activity group than in the lower physical activity group (P<.05). In the interventional study, 12-week aerobic exercise training significantly decreased urinary L-FABP levels (P<.01). Furthermore, the relative changes in urinary L-FABP levels were significantly correlated with the relative changes in physical activity levels and mean arterial pressure after intervention (r=-.374 and r=.530, respectively). Our results revealed that the urinary L-FABP levels were lower in the higher physical activity individuals, and aerobic exercise training decreased urinary L-FABP levels. These results suggest that habitual exercise appears to be associated with a decrease in the degree of several stresses on renal proximal tubule and to be beneficial for kidney health in middle-aged and older adults.

Scandinavian Journal of Medicine & Science in Sports


Relationship between exercise capacity and urinary liver-type fatty acid-binding protein in middle-aged and older individuals.


Increased N-Acetyltaurine in the Skeletal Muscle After Endurance Exercise in Rat.

Taurine is metabolized to a novel metabolite, N-acetyltaurine (NAT), through N-acetylation with acetate. Furthermore, NAT production increases when the endogenous production of acetate is elevated in some situations, such as alcohol catabolism and endurance exercise. We have previously reported that both the serum concentration and urinary excretion of NAT from humans were increased after endurance exercise, and that NAT was secreted by cultured skeletal muscle cells exposed to both acetate and taurine. The present study evaluated the hypothesis that NAT is synthesized in the skeletal muscle after endurance exercise. Normal rats were loaded to a transient treadmill running until exhaustion. Serum, skeletal muscle, and liver were collected immediately after the exercise. The NAT concentration in the plasma and in the soleus muscle from the exercised rats was significantly increased compared to that in the samples from the sedentary control rats. There was a significant positive correlation in the NAT concentration between the plasma and soleus muscle. The NAT concentration in the liver was unchanged after the endurance exercise. These results confirm that the significantly increased NAT in both the serum and urine after endurance exercise is derived from NAT synthesis in the skeletal muscle.

Advances in Experimental Medicine and Biology


Acute Effect of High-Intensity Eccentric Exercise on Vascular Endothelial Function in Young Men.

Choi, Y, Akazawa, N, Zempo-Miyaki, A, Ra, S-G, Shiraki, H, Ajisaka, R, and Maeda, S. Acute effect of high-intensity eccentric exercise on vascular endothelial function in young men. J Strength Cond Res 30(8): 2279-2285, 2016-Increased central arterial stiffness is as an independent risk factor for cardiovascular disease. Evidence regarding the effects of high-intensity resistance exercise on vascular endothelial function and central arterial stiffness is conflicting. The purpose of this study was to examine the effects of acute high-intensity eccentric exercise on vascular endothelial function and central arterial stiffness. We evaluated the acute changes in endothelium-dependent flow-mediated dilation (FMD), low-flow-mediated constriction (L-FMC), and arterial stiffness after high-intensity eccentric exercise. Seven healthy, sedentary men (age, 24 ± 1 year) performed maximal eccentric elbow flexor exercise using their nondominant arm. Before and 45 minutes after eccentric exercise, carotid arterial compliance and brachial artery FMD and L-FMC in the nonexercised arm were measured. Carotid arterial compliance was significantly decreased, and β-stiffness index significantly increased after eccentric exercise. Brachial FMD was significantly reduced after eccentric exercise, whereas there was no significant difference in brachial L-FMC before and after eccentric exercise. A positive correlation was detected between change in arterial compliance and change in FMD (r = 0.779; p 0.05), and a negative correlation was detected between change in β-stiffness index and change in FMD (r = -0.891; p < 0.01) with eccentric exercise. In this study, acute high-intensity eccentric exercise increased central arterial stiffness; this increase was accompanied by a decrease in endothelial function caused by reduced endothelium-dependent vasodilation but not by a change in endothelium-dependent vasoconstriction.

Journal of Strength and Conditioning Research


Effects of Cold Stimulation on Mitochondrial Activity and VEGF Expression in vitro.

We aimed to clarify the effects of cold stimulation at various temperatures on mitochondrial activity and vascular endothelial growth factor (VEGF) expression in vitro. Human fibroblast, human mesenchymal stem cell, and rat skeletal muscle myoblast cell lines were used. For each cell type, cells were divided into 4 groups and stimulated in various cold temperatures (0, 4, 17 and 25°C) 3 times for 15 min each by placement on crushed ice or floating on cold water set at each temperature. Control cells were subjected to warm water at 37°C. Factors related to mitochondrial activity, mitochondrial DNA copy numbers, and VEGF expression were analyzed 24 h after the last cold stimulation. In all cell types, significant increases of factors related to mitochondrial activity and mitochondrial DNA copy numbers were seen in the 4°C and 17°C-stimulated cells compared with control cells. In rat skeletal muscle cells stimulated at 4°C, VEGF expression significantly increased compared to the control cells. Our data suggest that cold stimulation at certain temperatures promotes mitochondrial activity, biogenesis and VEGF expression.

International Journal of Sports Medicine


Taurine supplementation attenuates delayed increase in exercise-induced arterial stiffness.

There is a delayed increase in arterial stiffness after eccentric exercise that is possibly mediated by the concurrent delayed increase in circulating oxidative stress. Taurine has anti-oxidant action, and taurine supplementation may be able to attenuate the increase in oxidative stress after exercise. The purpose of the present study was to investigate whether taurine supplementation attenuates the delayed increase in arterial stiffness after eccentric exercise. In the present double-blind, randomized, and placebo-controlled trial, we divided 29 young, healthy men into 2 groups. Subjects received either 2.0 g of placebo (n = 14) or taurine (n = 15) 3 times per day for 14 days prior to the exercise, on the day of exercise, and the following 3 days. The exercise consisted of 2 sets of 20 maximal-effort eccentric repetitions with the nondominant arm only. On the morning of exercise and for 4 days thereafter, we measured serum malondialdehyde (MDA) and carotid-femoral pulse wave velocity (cfPWV) as indices of oxidative stress and arterial stiffness, respectively. On the third and fourth days after exercise, both MDA and cfPWV significantly increased in the placebo group. However, these elevations were significantly attenuated in the taurine group. The increase in MDA was associated with an increase in cfPWV from before exercise to 4 days after exercise (r = 0.597, p < 0.05) in the placebo group, but not in the taurine group. Our results suggest that delayed increase in arterial stiffness after eccentric exercise was probably affected by the exercise-induced oxidative stress and was attenuated by the taurine supplementation.


Effect of closed fracture on spot urinary thiobarbituric acid reactive substance level in old rats

Gazzetta Medica Italiana Archivio per le Scienze Mediche


Influence of aerobic exercise training on post-exercise responses of aortic pulse pressure and augmentation pressure in postmenopausal women.

Central arterial blood pressure (BP) is more predictive of future cardiovascular events than is brachial BP because it reflects the BP load imposed on the left ventricle with greater accuracy. However, little is known about the effects of exercise training on central hemodynamic response to acute exercise. The purpose of the present study was to determine the influence of an aerobic exercise regimen on the response of aortic BP after a single aerobic exercise in postmenopausal women. Nine healthy postmenopausal women (age: 61 ± 2 years) participated in a 12-week aerobic exercise training regimen. Before and after the training, each subjects performed a single bout of cycling at ventilatory thresholds for 30 min. We evaluated the post-exercise aortic BP response, which was estimated via the general transfer function from applanation tonometry. After the initial pre-training aerobic exercise session, aortic BP did not change significantly: however, aortic pulse pressure and augmentation pressure were significantly attenuated after the single aerobic exercise session following the 12-week training regimen. The present study demonstrated that a regular aerobic exercise training regimen induced the post-exercise reduction of aortic pulse pressure and augmentation pressure. Regular aerobic exercise training may enhance post-exercise reduction in aortic BP.


Attenuation of indirect markers of eccentric exercise-induced muscle damage by curcumin.

It is concluded that theracurmin ingestion attenuates some aspects of muscle damage such as MVC loss and CK activity increase.


骨格筋糖代謝ならびにアミノ酸代謝関連の遺伝子発現に及ぼす タウリン投与の影響

骨格筋糖代謝ならびにアミノ酸代謝関連の遺伝子発現に及ぼす タウリン投与の影響

骨格筋の糖代謝ならびにセリン・グリシン・スレオニンのアミノ酸代謝の遺伝子発現に及ぼすタウリン投与の影響を明らかにすることを目的とした．ラットへ2 週間タウリンを経口投与し，腓腹筋内側頭白色部の遺伝子発現をDNA マイクロアレイ法にて網羅的に解析を行った．その結果，タウリン投与によって，骨格筋の糖代謝ならびにセリン・グリシン・スレオニンのアミノ酸代謝には影響を及ぼさなかった．タウリン投与のエネルギー代謝への影響は骨格筋よりむしろ肝臓など他の臓器への作用が関連する可能性が示唆された．


Increased N-acetyltaurine in serum and urine after endurance exercise in human.

Advances in Experimental Medicine and Biology


Taurine supplementation reduces eccentric exercise-induced delayed onset muscle soreness in young men.


Aerobic Exercise Training Improves Vascular Endothelial Function with an Increase in Circulating Klotho Levels in Postmenopausal Women

Circulating Klotho is expected to have vascular protective effects, including the enhancement of nitric oxide (NO) production by endothelial cells. Aerobic exercise training increases circulating Klotho levels and improves endothelial function, which decreases with aging. However, it is unclear whether aerobic exercise training-induced improvement in endothelial function is related to elevation of circulating Klotho levels. In the present study, we investigated the effect of aerobic exercise training on the correlation between plasma Klotho levels and endothelial function in postmenopausal women. First, we studied the correlation between plasma Klotho levels and flow-mediated vasodilation (FMD) as an index of endothelial function. FMD correlated positively with plasma Klotho levels, but the baseline diameter did not correlate with plasma Klotho levels. Second, we examined the effects of aerobic exercise training on plasma Klotho levels and FMD. After aerobic exercise training, plasma Klotho levels and FMD increased significantly. Furthermore, there was a positive correlation between the changes in plasma Klotho levels and those in FMD. These results suggested that an increase in circulating Klotho levels induced by aerobic exercise training may contribute to improvement of endothelial function.

Advances in Exercise and Sports Physiology


Lifestyle modification-induced increase in serum testosterone and SHBG decreases arterial stiffness in overweight and obese men


Metabolomics of salivary fatigue markers in soccer players after consecutive games.

Strenuous and consecutive exercise leads to fatigue symptoms in athletes. Metabolomics is a comprehensive method to assess metabolites that involves the measurements of the overall metabolic signature of biological samples. Using metabolomic analysis, we investigated the identification of salivary fatigue markers in soccer players after 3 consecutive days of a game program. One hundred twenty-two male soccer players participated in 3 consecutive days of a game program. To detect fatigued athletes, we measured indices of traditional fatigue symptoms, i.e., heart rate, body mass and mood, before and after the program. We detected 37 fatigued players throughout the program. Before and after the program, the saliva in these players was analyzed using capillary electrophoresis and time-of-flight mass spectrometry (CE-TOFMS) and a multivariate statistical technique, principal component analysis, was used to process the data. CE-TOFMS was used to identify 144 metabolites in the saliva of fatigued players. A significant metabolomic difference was observed before and after 3 consecutive days of a soccer game program. Interestingly, metabolites were all increased after the program (P < 0.001). The identified metabolites, including 3-methylhistidine, glucose 1- and 6-phosphate, taurine, and some amino acids, were involved in skeletal muscle catabolism, glucose metabolism, lipid metabolism, amino acid metabolism, and energy metabolism. Our work demonstrated some salivary metabolites were significantly increased in the fatigued players after consecutive days of short soccer matches. We propose that the detected salivary metabolites may be new fatigue markers in athletes.

Applied Physiology, Nutrition, and Metabolism


Plasma ADMA concentrations associate with aerobic fitness in postmenopausal women.

We found that plasma ADMA concentrations were associated with aerobic fitness in postmenopausal women. The results of this study suggest that habitual aerobic exercise may decrease plasma ADMA concentrations.


Aerobic exercise training decreases plasma asymmetric dimethylarginine concentrations with increase in arterial compliance in postmenopausal women.

We demonstrated that aerobic exercise training significantly decreased plasma ADMA concentrations with increase in carotid arterial compliance in postmenopausal women. These results suggest that reduction in ADMA may play an important role in the aerobic exercise training-induced increase in arterial compliance.


A cross-sectional study of plasma taurine concentration and vascular endothelial function in young men

若年男性における血漿タウリン濃度と血管内皮機能に関する横断研究


The change in salivary taurine level following 3 consecutive soccer match in collegiate male soccer players

男子大学サッカー選手における試合合宿前後の唾液中タウリン濃度の変動

Strenuous and consecutive exercise results in fatigue symptoms accompanied decrease in salivary secretory immunoglobulin A (sIgA) in athletes. On the other hand, it has been reported that plasma taurine concentration was increased after the high intensity exercise. However, change in salivary taurine concentration after strenuous and consecutive exercise is unknown. The purpose of this study was to investigate the relationship between fatigue symptoms and changes in salivary taurine concentration in collegiate male soccer players. Thirty seven collegiate male soccer players participated in three consecutive days of match program. To detect of fatigued players, we measured awakening heart rate and body weight. As the results of these two measurements, we divided subjects to two groups (non-fatigue group, n=15; fatigue group, n=22). We also measured salivary sIgA and taurine concentrations before and after program. Before the program, there were no significant differences in any parameters between two groups. Salivary flow rate and sIgA secretion rate were significantly decreased after the program in the fatigue group. Furthermore, salivary taurine concentration was significantly increased after the program in the fatigue group. In the non-fatigue group, there were no significant differences in any parameters during program. Our results indicated that salivary taurine concentration increased after consecutive high-intense exercise in the collegiate male soccer players.

Japanese Journal of Physical Fitness and Sports Medicine


Aerobic exercise training increases plasma Klotho levels and reduces arterial stiffness in postmenopausal women.

The Klotho gene is a suppressor of the aging phenomena, and the secretion as well as the circulation of Klotho proteins decrease with aging. Although habitual exercise has antiaging effects (e.g., a decrease in arterial stiffness), the relationship between Klotho and habitual exercise remains unclear. In the present study, we investigated the effect of habitual exercise on Klotho, with a particular focus on arterial stiffness. First, we examined the correlation between plasma Klotho concentration and arterial stiffness (carotid artery compliance and β-stiffness index) or aerobic exercise capacity [oxygen uptake at ventilatory threshold (VT)] in 69 healthy, postmenopausal women (50-76 years old) by conducting a cross-sectional study. Second, we tested the effects of aerobic exercise training on plasma Klotho concentrations and arterial stiffness. A total of 19 healthy, postmenopausal women (50-76 years old) were divided into two groups: control group and exercise group. The exercise group completed 12 wk of moderate aerobic exercise training. In the cross-sectional study, plasma Klotho concentrations positively correlated with carotid artery compliance and VT and negatively correlated with the β-stiffness index. In the interventional study, aerobic exercise training increased plasma Klotho concentrations and carotid artery compliance and decreased the β-stiffness index. Moreover, the changes in plasma Klotho concentration and arterial stiffness were found to be correlated. These results suggest a possible role for secreted Klotho in the exercise-induced modulation of arterial stiffness.

American Journal of Physiology, Heart and Circulatory Physiology


Effects of lifestyle modification on central blood pressure in overweight and obese men.

This study showed for the first time that lifestyle modification-induced weight loss decreases central systolic blood pressure in overweight and obese men. The decrease in central systolic blood pressure was associated with the reduction in arterial stiffness. These results suggest that lifestyle modification-induced reduction in arterial stiffness may contribute toward the decreased central systolic blood pressure in overweight and obese men.


Combined effect of branched-chain amino acids and taurine supplementation on delayed onset muscle soreness and muscle damage in high-intensity eccentric exercise.

A combination of 3.2 g BCAA and 2.0 g taurine, three times a day, for two weeks prior to and three days after exercise may be a useful nutritional strategy for attenuating exercise-induced DOMS and muscle damage.

Journal of the International Society of Sports Nutrition


The ameliorating effect of branched-chain amino acid ingestion on different types of muscle soreness after swimming and full-marathon running

The effectiveness of branched-chain amino acids (BCAA) ingestion on delayed onset muscle soreness (DOMS) has been established in experimental exercise involving eccentric contraction (ECC). This placebo-controlled, randomized, double-blind study evaluated the effect of BCAA ingestion on two types of muscle soreness after swimming (which generally involves little ECC) and immediate onset muscle soreness (IOMS) after a full-marathon and on systemic fatigue. Subjects were 32 swimmers competing in a university swim meet and 22 non-professional runners participating in a full-marathon race. They received either 3.2g of BCAA or placebo three times a day, from the day before to two days after their events. Systemic fatigue and soreness in muscle regions (seven regions in swimmers, six in runners) were evaluated using a numeric rating scale before, immediately after, and one and two days after the events. In the swimmers, muscle soreness in the upper body (neck, upper arm, back, and low back), buttock, and thigh and systemic fatigue were significantly decreased after two days in the BCAA group. In the runners, IOMS occurred in all examined regions immediately after the marathon, and BCAA ingestion significantly decreased both muscle soreness in the anterior thigh, anterior lower leg, and buttock and systemic fatigue within two days. This study showed the effectiveness of BCAA ingestion on improving systemic fatigue, muscle soreness after swimming, and IOMS after a full-marathon. On the basis of these results, it is proposed that BCAA supplements can be administered to ameliorate muscle soreness and fatigue induced by various types of exercise.

Advances in Exercise and Sports Physiology


Additional effects of taurine on the benefits of BCAA intake for the delayed-onset muscle soreness and muscle damage induced by high-intensity eccentric exercise.

Taurine (TAU) has a lot of the biological, physiological, and pharmocological functions including anti-inflammatory and anti-oxidative stress. Although previous studies have appreciated the effectiveness of branched-chain amino acids (BCAA) on the delayed-onset muscle soreness (DOMS), consistent finding has not still convinced. The aim of this study was to examine the additional effect of TAU with BCAA on the DOMS and muscle damages after eccentric exercise. Thirty-six untrained male volunteers were equally divided into four groups, and ingested a combination with 2.0 g TAU (or placebo) and 3.2 g BCAA (or placebo), thrice a day, 2 weeks prior to and 4 days after elbow flexion eccentric exercise. Following the period after eccentric exercise, the physiological and blood biochemical markers for DOMS and muscle damage showed improvement in the combination of TAU and BCAA supplementation rather than in the single or placebo supplementations. In conclusion, additional supplement of TAU with BCAA would be a useful way to attenuate DOMS and muscle damages induced by high-intensity exercise.

Advances in Experimental Medicine and Biology


Effect of taurine supplementation on the alterations in amino Acid content in skeletal muscle with exercise in rat.

Taurine included abundantly in skeletal muscle, particularly in the slow-twitch fibers, enhances exercise performance. However, the exact mechanisms for this effect have been unclear. The present study investigated the influence of taurine supplementation on amino acids profile in skeletal muscles as one of mechanisms in the enhancement of exercise performance induced by taurine. In the rats that received taurine solution, amino acids concentrations were comprehensively quantified in two portions with different fiber compositions in the fast-twitch fiber dominant (FFD) gastrocnemius muscle after 2 weeks, and in the gastrocnemius and additional other FFD muscles, liver, and plasma with exhausted exercise after 3 weeks. In the FFD muscles after 2 weeks, a common phenomenon that decreased concentrations of threonine (-16%), serine (-15~-16%), and glycine (-6~-16%) were observed, and they are categorized in the pyruvate precursors for hepatic gluconeogenesis rather than biosynthesis, polar, and side-chain structures. The decreases in the three amino acids were significantly emphasized after an additional week of taurine supplementation in the FFD muscles (p values in three amino acids in these tissues were less than 0.001-0.05), but not in the liver and plasma, accompanied with significantly increase of running time to exhaustion (p <0.05). In contrast, the three amino acids (threonine and serine; p < 0.05, glycine; p < 0.01) and alanine (p < 0.01) in the liver were significantly decreased and increased, respectively, following the exhaustive exercise. In conclusion, the taurine-induced reductions of these amino acids in skeletal muscle might be one of the mechanisms which underpin the enhancement of exercise performance by taurine. Key pointsTaurine ingestion significantly decreased certain amino acids in skeletal muscles accompanied with enhanced exercise performance.The decreased amino acids in common were threonine, serine, and glycine, but not alanine; pyruvate precursor for gluconeogenesis.The alteration of three amino acids in muscles was maintained after exhausted exercise.The muscular alterations of them might be one of taurine-induced roles on exercise performance.


タウリン摂取がマウス骨格筋の糖・脂質代謝関連因子へ及ぼす影響

タウリン摂取がマウス骨格筋の糖・脂質代謝関連因子へ及ぼす影響


Exercise-induced changes in amino acid levels in skeletal muscle and plasma

During exercise, amino acid oxidation and protein breakdown are enhanced while protein synthesis is suppressed, even though protein does not constitute a quantitatively important energy source. In response to exercise-induced stimulation, various changes in free amino acids occur in skeletal muscle to meet physiological demands. Plasma amino acids are also under the influence of various types of stress, including exercise stress. For example, acute exercise increases alanine and glutamine levels, but decreases glutamate levels in skeletal muscle. At the same time, it increases tryptophan and taurine levels, but decreases glutamine levels in plasma. Prolonged exercise decreases glutamine and glutamate levels, while increasing tyrosine and phenylalanine levels in skeletal muscle. Furthermore, when prolonged exercise-induced changes in amino acid levels are compared between trained and untrained individuals, glutamate and taurine levels in skeletal muscle and phenylalanine, leucine, isoleucine, and tyrosine levels in plasma are higher in trained individuals. This review provides an overview of changes in amino acid levels in skeletal muscle and plasma, with a focus on changes induced by exercise.

The Journal of Physical Fitness and Sports Medicine