52 results on '"Naito, Hisashi"'
Search Results
2. Estimating Energy Cost of Body Weight Resistance Exercise Using a Multistage Exercise Test
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Nakagata, Takashi, Yamada, Yosuke, and Naito, Hisashi
- Abstract
Nakagata, T, Yamada, Y, and Naito, H. Estimating energy cost of body weight resistance exercise using a multistage exercise test. J Strength Cond Res36(5): 1290–1296, 2022—The purpose of this study was to examine energy cost of body weight resistance exercises with slow movement in young men using a multistage exercise test. Fifteen men aged 21–29 years performed 3 exercises (heel-raise, squat, and push-up) at different frequencies (1, 2, 3, 4, 5, and 6 repetitions·min−1). Oxygen consumption was measured using indirect calorimetry; we then computed a simple linear regression between aerobic energy expenditure (EE) and repetition frequency. The slope coefficient in the regression represents the energy cost of those exercises; we compared the extrapolated EE for a frequency of 10 repetitions·min−1. Gross EE increased linearly with repetition frequency in all subjects (y= ax+ b). Energy cost was significantly greater in the case of the push-up than in the case of the squat {squat: 0.50 ± 0.14 (95% confidence interval [CI], 0.42–0.58); push-up: 0.77 ± 0.20 kcal (95% CI, 0.66–0.88); and the heel-raise elicited the lowest energy cost: 0.13 ± 0.04 kcal (95% CI, 0.11–0.15)}. Extrapolated EE at 10 repetitions·min−1was 2.7 ± 0.5 kcal (2.3 metabolic equivalents [METs]), 6.3 ± 1.4 kcal (5.4 METs), and 9.2 ± 2.1 kcal (7.8 METs), respectively, according to the regression based on aerobic EE. These results will be useful for health professionals in prescribing resistance exercise programs improving muscle fitness and considering for weight management.
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- 2022
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3. Blood flow restriction in human skeletal muscle during rest periods after high-load resistance training down-regulates miR-206 and induces Pax7.
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Torma, Ferenc, Gombos, Zoltan, Fridvalszki, Marcell, Langmar, Gergely, Tarcza, Zsofia, Merkely, Bela, Naito, Hisashi, Ichinoseki-Sekine, Noriko, Takeda, Masaki, Murlasits, Zsolt, Osvath, Peter, and Radak, Zsolt
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BLOOD flow restriction training ,MICRORNA ,SKELETAL muscle physiology - Abstract
• Blood flow restriction at resting periods of high-intensity load exercise increases Pax7 expression. • miR-206 levels significantly decreased in the blood flow restriction leg compared to the control. • Blood flow restriction can cause DNA damage, judging from the increase in messenger RNA levels of Ku70. [Display omitted] Blood flow restriction (BFR) with low-intensity resistance training has been shown to result in hypertrophy of skeletal muscle. In this study, we tested the hypothesis that BFR during the rest periods between acute, high-intensity resistance exercise sessions (70% of 1 repetition maximum, 7 sets with 10 repetitions) enhances the effects of the resistance training. A total of 7 healthy young men performed squats, and between sets BFR was carried out on one leg while the other leg served as a control. Because BFR was applied during rest periods, even severe occlusion pressure (approximately 230 mmHg), which almost completely blocked blood flow, was well-tolerated by the participants. Five muscle-specific microRNAs were measured from the biopsy samples, which were taken 2 h after the acute training. Doppler data showed that the pattern of blood flow recovery changed significantly between the first and last BFR. microRNA-206 levels significantly decreased in the BFR leg compared to the control. The mRNA levels of RAC-β serine/threonine-protein kinase v22, nuclear respiratory factor 1, vascular endothelial growth factor, lupus Ku autoantigen protein p70 genes (p < 0.05), and paired box 7 (p < 0.01) increased in the BFR leg. The protein levels of paired box 7, nuclear respiratory factor 1, and peroxisome proliferator-activated receptor γ coactivator 1α did not differ between the BFR leg and the control leg. BFR, during the rest periods of high-load resistance training, could lead to mRNA elevation of those proteins that regulate angiogenesis, mitochondrial biogenesis, and muscle hypertrophy and repair. However, BFR also can cause DNA damage, judging from the increase in mRNA levels of lupus Ku autoantigen protein p70. [ABSTRACT FROM AUTHOR]
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- 2021
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4. Assessing the need to use sport supplements: The mediating role of sports supplement beliefs.
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Murofushi, Yuka, Kawata, Yujiro, Nakamura, Miyuki, Yamaguchi, Shinji, Sunamoto, Saori, Fukamachi, Hanako, Aono, Hiroshi, Kamihigashi, Etsuko, Takazawa, Yuji, Naito, Hisashi, and Hurst, Philip
- Abstract
Sport supplement use by athletes can lead to unintentional anti-doping rule violations (ADRVs) due to the contamination of prohibited substances. This phenomenon underscores the need for athletes to reconsider their supplement use and assess their safety, efficacy, and necessity—a process we referred to as ' reconsideration of supplement use'. Additionally, a body of research using the Sport Supplement Beliefs Scale (SSBS) has shown that when an athlete believes that supplements improve performance, they may be more likely to progress to doping in the future. However, most research is conducted in English speaking countries and there is a lack of validated measures in other languages. Therefore, in this multi-study research, we validated a Japanese version of the SSBS (Study 1) and examined relationships between perceived risk of ADRV due to supplements, reconsideration of supplement use, sports supplement beliefs and sport supplement use (Study 2). In Study 1, we created a Japanese version of the SSBS (SSBS-J) using back-translation. In order to evaluate the reliability and validity of the scale, we utilized data from 356 university athletes, which were divided into two distinct cohorts, who reported their frequency and number of supplements used. Internal consistency and fit of the SSBS-J were evaluated using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) and the scale's ability to determine supplement use was assessed using linear regression analysis and t -tests. In Study 2, 525 university athletes (64.6 % men, M age = 18.7 ± 0.7 years) were asked to complete measures related to the perceived risk of committing an ADRV due to supplement use, SSBS-J and sport supplement use. In Study 1, the SSBS-J showed high internal consistency (α = 0.876), a one-factor structure similar to the original version, and good model fit. Linear regression indicated that the SSBS-J scores were significantly associated with the frequency and number of supplements used and differences were found between scores of supplement users (21.51 ± 6.54) and non-users (16.48 ± 6.14) (p <.001). Discriminant analysis correctly classified 64.7 % of supplement users and 61.0 % of non-users. In Study 2, ADRV awareness was indirectly related to sport supplement use via sport supplement beliefs (p <.001). Our findings suggest that ADRV awareness can influence reconsideration of supplement use and subsequently deter supplement use mediated by sport supplement beliefs. These insights emphasize the importance of promoting doping risk awareness, revisiting supplement use, and mitigating sport supplement beliefs to reduce inappropriate or unnecessary supplement use among athletes. From an anti-doping perspective, this insight is valuable in guiding athlete education regarding supplement use. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Blood flow restriction in human skeletal muscle during rest periods after high-load resistance training down-regulates miR-206 and induces Pax7
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Torma, Ferenc, Gombos, Zoltan, Fridvalszki, Marcell, Langmar, Gergely, Tarcza, Zsofia, Merkely, Bela, Naito, Hisashi, Ichinoseki-Sekine, Noriko, Takeda, Masaki, Murlasits, Zsolt, Osvath, Peter, and Radak, Zsolt
- Abstract
•Blood flow restriction at resting periods of high-intensity load exercise increases Pax7 expression.•miR-206 levels significantly decreased in the blood flow restriction leg compared to the control.•Blood flow restriction can cause DNA damage, judging from the increase in messenger RNA levels of Ku70.
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- 2021
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6. Crystal Structure Generation Based on Polyhedra Using Dual Periodic Graphs
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Yokoyama, Tomoyasu, Ichikawa, Kazuhide, and Naito, Hisashi
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Crystal structure design is important for the discovery of new highly functional materials because the crystal structure strongly influences material properties. Crystal structures are composed of space-filling polyhedra, which affect material properties such as ionic conductivity and the dielectric constant. However, most conventional methods of crystal structure prediction use random structure generation methods that do not take space-filling polyhedra into account, contributing to the inefficiency of materials development. In this work, we propose a crystal structure generation method based on discrete geometric analysis of polyhedra information. In our method, the shape and connectivity of a space-filling polyhedron are represented as a dual periodic graph, and the crystal structure is generated by the standard realization of this graph. We demonstrate that this method can correctly generate face-centered cubic, hexagonal close-packed, and body-centered cubic structures from dual periodic graphs. This work is a first step toward generating undiscovered crystal structures based on the target polyhedra, leading to major advances in materials design in areas such as electronics and energy storage.
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- 2024
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7. Biological Effects of IL-26 on T Cell–Mediated Skin Inflammation, Including Psoriasis
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Itoh, Takumi, Hatano, Ryo, Komiya, Eriko, Otsuka, Haruna, Narita, Yuka, Aune, Thomas M., Dang, Nam H., Matsuoka, Shuji, Naito, Hisashi, Tominaga, Mitsutoshi, Takamori, Kenji, Morimoto, Chikao, and Ohnuma, Kei
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Psoriasis is a chronic inflammatory skin disease characterized mainly by epidermal hyperplasia, scaling, and erythema; T helper 17 cells have a role in its pathogenesis. Although IL-26, known as a T helper 17 cytokine, is upregulated in psoriatic skin lesions, its precise role is unclear. We investigated the role of IL-26 in the imiquimod-induced psoriasis-like murine model using human IL-26transgenic mice. Erythema symptoms induced by daily applications of imiquimod increased dramatically in human IL-26transgenic mice compared with controls. Vascularization and immune cell infiltration were prominent in skin lesions of human IL-26transgenic mice. Levels of fibroblast growth factor (FGF) 1, FGF2, and FGF7 were significantly upregulated in the skin lesions of imiquimod-treated human IL-26transgenic mice and psoriasis patients. In vitro analysis demonstrated that FGF1, FGF2, and FGF7 levels were elevated in human keratinocytes and vascular endothelial cells following IL-26 stimulation. Furthermore, IL-26 acted directly on vascular endothelial cells, promoting proliferation and tube formation, possibly through protein kinase B, extracellular signal–regulated kinase, and NF-κB pathways. Moreover, similar effects of IL-26 were observed in the murine contact hypersensitivity model, indicating that these effects are not restricted to psoriasis. Altogether, our data indicate that IL-26 may be a promising therapeutic target in T cell–mediated skin inflammation, including psoriasis.
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- 2019
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8. Sex differences in forkhead box O3a signaling response to hindlimb unloading in rat soleus muscle
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Yoshihara, Toshinori, Natsume, Toshiharu, Tsuzuki, Takamasa, Chang, Shuo-wen, Kakigi, Ryo, Sugiura, Takao, and Naito, Hisashi
- Abstract
We tested the hypothesis that there are sex differences in hindlimb unloading-induced activation of the forkhead box subfamily O3a (FoxO3a) signaling pathway in rat soleus muscle. Age-matched male and female Wistar rats were subjected to hindlimb unloading, and the soleus muscle was removed before or 1 or 7 days after unloading. Female rats showed greater percent changes in relative soleus muscle weight than males. FoxO3a phosphorylation was lower in females than in males and was associated with higher levels of protein ubiquitination 7 days after unloading. Heat shock protein 72 (Hsp72) levels were lower in female rats and increased in males during unloading. Female rats showed slightly higher myostatin levels, which showed a non-significant decline in male rats following unloading. Thus, males and females show different responses to the FoxO3a/ubiquitin–proteasome pathway following hindlimb unloading in rat soleus muscle, which may be associated with differences in Hsp72 expression and myostatin signaling.
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- 2019
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9. Effect of a combination of astaxanthin supplementation, heat stress, and intermittent reloading on satellite cells during disuse muscle atrophy
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Yoshihara, Toshinori, Sugiura, Takao, Miyaji, Nobuyuki, Yamamoto, Yuki, Shibaguchi, Tsubasa, Kakigi, Ryo, Naito, Hisashi, Goto, Katsumasa, Ohmori, Daijiro, and Yoshioka, Toshitada
- Abstract
We examined the effect of a combination of astaxanthin (AX) supplementation, repeated heat stress, and intermittent reloading (IR) on satellite cells in unloaded rat soleus muscles. Forty-nine male Wistar rats (8-week-old) were divided into control, hind-limb unweighting (HU), IR during HU, IR with AX supplementation, IR with repeated heat stress (41.0–41.5 °C for 30 min), and IR with AX supplementation and repeated heat stress groups. After the experimental period, the antigravitational soleus muscle was analyzed using an immunohistochemical technique. Our results revealed that the combination of dietary AX supplementation and heat stress resulted in protection against disuse muscle atrophy in the soleus muscle. This protective effect may be partially due to a higher satellite cell number in the atrophied soleus muscle in the IR/AX/heat stress group compared with the numbers found in the other groups. We concluded that the combination treatment with dietary AX supplementation and repeated heat stress attenuates soleus muscle atrophy, in part by increasing the number of satellite cells.
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- 2018
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10. Short-term treadmill exercise in a cold environment does not induce adrenal Hsp72 and Hsp25 expression
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Akin, Senay, Naito, Hisashi, Ogura, Yuji, Ichinoseki-Sekine, Noriko, Kurosaka, Mitsutoshi, Kakigi, Ryo, and Demirel, Haydar A.
- Abstract
Heat shock proteins (Hsps) have a critical role in maintaining cellular homeostasis and in protecting cells from a range of acute and chronic stressful conditions. Treadmill running exercise results in increased Hsp72 and Hsp25 levels in various tissues and heat production during exercise has been shown to be the main factor for the increased levels of Hsp72 in myocardium. Since the adrenal gland plays a vital role in general response to stress, regulation of Hsps in adrenal glands following stressful events seems to be critical for controlling the whole-body stress response appropriately. This study tested the hypothesis of whether elevation of temperature is solely responsible for exercise-induced adrenal Hsp72 and Hsp25 expression. Female Sprague–Dawley rats (3 months old) were randomly assigned to either a sedentary control group or one of two treadmill-running groups: a cold exercise group run in a cold room at 4 °C (CE), and a warm exercise group run at 25 °C temperature (WE). Animals were run 60 min a day at 30 m min−1speed for 4 consecutive days following adaptation to treadmill exercise. Exercise resulted in a significant elevation of body temperature only in the WE group (p< 0.05). Adrenal Hsp72 and Hsp25 levels were significantly higher in the WE group compare to the other groups (p< 0.05). These data demonstrated that exercise-related elevations of body temperature could be the only factor for the inductions of adrenal Hsp72 and Hsp25 expression.
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- 2017
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11. Pulmonary kinematic analysis with non-rigid deformable registration for detecting localised emphysema
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Higashi, Ryosuke, Sera, Toshihiro, Naito, Hisashi, Matsumoto, Takeshi, and Tanaka, Masao
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Emphysema is defined pathologically as destruction of alveolar walls and permanent enlargement of the airspaces. Detection of localised emphysema is difficult using conventional methods because the parameters evaluate macroscopic lung function. In this study, the pulmonary kinematics of control and emphysema model mice were evaluated to investigate whether pulmonary kinematic analysis is useful for diagnosing localised emphysema. Emphysema model mice were induced by porcine pancreatic elastase treatment, and 3D micro-CT images were obtained during stepwise inflation and deflation. The pulmonary vessels and pleura were segmented at each pressure, and pulmonary deformation and volumetric strain between consecutive different pressures were calculated by non-rigid deformable registration. In particular, during low lung pressure, craniocaudal deformation and volumetric strain were higher in the regions where the alveolar enlargement was observed in emphysema model mice. Furthermore, volumetric strain of emphysema model mice was larger at alveolar enlargement. On the other hand, there were no significant differences between control and emphysema model mice in conventional macroscopic lung pressures and volume relationships. The present results indicate that pulmonary kinematic analysis, examining craniocaudal deformation, and volumetric strain may become useful for the clinical assessment of localised emphysema.
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- 2017
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12. Circadian rhythm of intracellular protein synthesis signaling in rat cardiac and skeletal muscles
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Chang, Shuo-wen, Yoshihara, Toshinori, Machida, Shuichi, and Naito, Hisashi
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Intracellular signaling exhibits circadian variation in the suprachiasmatic nucleus and liver. However, it is unclear whether circadian regulation also extends to intracellular signaling pathways in the cardiac and skeletal muscles. Here, we examined circadian variation in the intracellular mammalian target of rapamycin (mTOR)/70 kDa ribosomal protein S6 kinase 1 (p70S6K) and extracellular signal-regulated kinase (ERK) pathways, which regulate protein synthesis in rat cardiac and skeletal muscles. Seven-week-old male Wistar rats were assigned to six groups: Zeitgeber time (ZT) 2, ZT6, ZT10, ZT14, ZT18, and ZT22 (ZT0, lights on; ZT12, lights off). The cardiac, plantaris, and soleus muscles were removed after a 12-h fasting period, and signal transducers involved in protein synthesis (mTOR, p70S6K, and ERK) were analyzed by western blotting. Circadian rhythms of signal transducers were observed in both cardiac (mTOR, p70S6K, and ERK) and plantaris (p70S6K and ERK) muscles (p<0.05), but not in the soleus muscle. In the cardiac muscle, the phosphorylation rate of mTOR was significantly higher at ZT6 (peak) than at ZT18 (bottom), and the phosphorylation rate of p70S6K was significantly higher at ZT2 (peak) than at ZT18 (bottom). In contrast, in the plantaris muscle, the phosphorylation rate of ERK was significantly lower at ZT2 (bottom) than at ZT18 (peak). Our data suggested that protein synthesis via mTOR/p70S6K and ERK signaling molecules exhibits circadian variation in rat cardiac and fast-type plantaris muscles.
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- 2017
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13. Dietary astaxanthin supplementation attenuates disuse-induced muscle atrophy and myonuclear apoptosis in the rat soleus muscle
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Yoshihara, Toshinori, Yamamoto, Yuki, Shibaguchi, Tsubasa, Miyaji, Nobuyuki, Kakigi, Ryo, Naito, Hisashi, Goto, Katsumasa, Ohmori, Daijiro, Yoshioka, Toshitada, and Sugiura, Takao
- Abstract
Extended periods of skeletal muscle disuse results in muscle atrophy and weakness. Currently, no therapeutic treatment is available for the prevention of this problem. Nonetheless, growing evidence suggests that prevention of disuse-induced oxidative stress in inactive muscle fibers can delay inactivity-induced muscle wasting. Therefore, this study tested the hypothesis that dietary supplementation with the antioxidant astaxanthin would protect against disuse muscle atrophy, in part, by prevention of myonuclear apoptosis. Wistar rats (8 weeks old) were divided into control (CT, n= 9), hindlimb unloading (HU, n= 9), and hindlimb unloading with astaxanthin (HU + AX, n= 9) groups. Following 2 weeks of dietary supplementation, rats in the HU and HU + AX groups were exposed to unloading for 7 days. Seven-day unloading resulted in reduced soleus muscle weight and myofiber cross-sectional area (CSA) by ~30 and ~47 %, respectively. Nonetheless, relative muscle weights and CSA of the soleus muscle in the HU + AX group were significantly greater than those of the HU group. Moreover, astaxanthin prevented disuse-induced increase in the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive nuclei. We conclude that astaxanthin supplementation prior to and during hindlimb unloading attenuates soleus muscle atrophy, in part, by suppressing myonuclear apoptosis.
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- 2017
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14. Longitudinal changes of grip strength and forearm muscle thickness in young children
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Abe, Takashi, Ozaki, Hayao, Abe, Akemi, Machida, Shuichi, Naito, Hisashi, and Loenneke, Jeremy P.
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- 2023
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15. Losartan treatment attenuates hindlimb unloading-induced atrophy in the soleus muscle of female rats via canonical TGF-β signaling
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Yoshihara, Toshinori, Takaragawa, Mizuki, Dobashi, Shohei, and Naito, Hisashi
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We investigated the protective effect of losartan, an angiotensin II type 1 receptor blocker, on soleus muscle atrophy. Age-matched male and female Wistar rats were subjected to hindlimb unloading, and the soleus muscle was removed on days 1 and 7 for analysis. Females showed greater reductions in relative weight and myofiber cross-sectional area of the soleus muscle than males on day 7 post-hindlimb unloading. Losartan partially protected females against muscle atrophy. Activation of the canonical TGF-β signaling pathway, assessed via Smad2/3 phosphorylation, was lower in females following losartan treatment and associated with lower levels of protein ubiquitination after 1 (myofibril) and 7 (cytosol) days of unloading. However, no effect was observed in non-canonical TGF-β signaling (p44/p42 and p38 MAPK phosphorylation) in males or females during unloading. Our results suggest that losartan provides partial protection against hindlimb unloading-induced soleus muscle atrophy in female rats, possibly associated with decreased canonical TGF-β signaling.
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- 2022
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16. Exercise training improves obesity-induced inflammatory signaling in rat brown adipose tissue
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Tsuzuki, Takamasa, Yoshihara, Toshinori, Ichinoseki-Sekine, Noriko, Kobayashi, Hiroyuki, Negishi, Takayuki, Yukawa, Kazunori, and Naito, Hisashi
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Chronic inflammation is considered as an etiology of obesity and type 2 diabetes. Brown adipose tissue (BAT) of obese animals shows increased inflammation. Regular exercise has anti-inflammatory effects; however, the effects of exercise training on BAT inflammation in obese animals remain unclear. Thus, this study aimed to investigate the effects of exercise training on inflammation-related signaling in the BAT of obese and diabetic rats. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an obese/diabetic rodent model, were randomly divided into either sedentary (n = 11) or exercise training (n = 8) groups. Long-Evans Tokushima Otsuka (LETO; n = 9) rats were used as the nondiabetic sedentary controls. Exercise training using a treadmill was conducted 4 days per week for 20 weeks, starting at 5 weeks old. As a result, exercise training attenuated the phosphorylation levels of p65 and mitogen-activated protein kinases in the BAT of OLETF rats, concurrently with the improvement of obesity and systemic glucose tolerance. Moreover, exercise training decreased oxidative stress and increased the antioxidant and anti-inflammatory protein levels in the BAT. Conversely, exercise training did not alter the expression levels of uncoupling protein-1 and oxidative phosphorylation-related proteins in the BAT, which were lower in the OLETF rats than the LETO rats. In conclusion, our data suggest that exercise training prevents the activation of inflammatory signaling in the BAT of obese/diabetic rats.
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- 2022
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17. Effects of icing or heat stress on the induction of fibrosis and/or regeneration of injured rat soleus muscle
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Shibaguchi, Tsubasa, Sugiura, Takao, Fujitsu, Takanori, Nomura, Takumi, Yoshihara, Toshinori, Naito, Hisashi, Yoshioka, Toshitada, Ogura, Akihiko, and Ohira, Yoshinobu
- Abstract
The effects of icing or heat stress on the regeneration of injured soleus muscle were investigated in male Wistar rats. Bupivacaine was injected into soleus muscles bilaterally to induce muscle injury. Icing (0 °C, 20 min) was carried out immediately after the injury. Heat stress (42 °C, 30 min) was applied every other day during 2–14 days after the bupivacaine injection. Injury-related increase in collagen deposition was promoted by icing. However, the level of collagen deposition in heat-stressed animals was maintained at control levels throughout the experimental period and was significantly lower than that in icing-treated animals at 15 and 28 days after bupivacaine injection. Furthermore, the recovery of muscle mass, protein content, and muscle fiber size of injured soleus toward control levels was partially facilitated by heat stress. These results suggest that, compared with icing, heat stress may be a beneficial treatment for successful muscle regeneration at least by reducing fibrosis.
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- 2016
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18. Immobilization induces nuclear accumulation of HDAC4 in rat skeletal muscle
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Yoshihara, Toshinori, Machida, Shuichi, Kurosaka, Yuka, Kakigi, Ryo, Sugiura, Takao, and Naito, Hisashi
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The study described herein aimed to examine changes in HDAC4 and its downstream targets in immobilization-induced rat skeletal muscle atrophy. Eleven male Wistar rats were used, and one hindlimb was immobilized in the plantar flexion position using a plaster cast. The contralateral, non-immobilized leg served as an internal control. After 10 days, the gastrocnemius muscles were removed from both hindlimbs. Ten days of immobilization resulted in a significant reduction (−27.3 %) in gastrocnemius muscle weight. A significant decrease in AMPK phosphorylation was also observed in nuclear fractions from immobilized legs relative to the controls. HDAC4 expression was significantly increased in immobilized legs in both the cytoplasmic and nuclear fractions. Moreover, Myogenin and MyoD mRNA levels were upregulated in immobilized legs, resulting in increased Atrogin-1 mRNA expression. Our data suggest that nuclear HDAC4 accumulation is partly related to immobilization-induced muscle atrophy.
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- 2016
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19. Effect of high-intensity intermittent training under normobaric hypoxia on mitochondrial-related protein expression in rat gastrocnemius muscle.
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Shohei Dobashi, Toshinori Yoshiliara, and Naito Hisashi
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Purpose: This study was to investigate the effect of high-intensity intermittent training (HITT) under normobaric hypoxic conditions on mitochondrial biogenesis and fission/fusion-related protein expressions in rat gastrocnemius muscle. Methods: Five-week-old Wistar male rats (n = 24) were randonily assigned to sedentary or training groups under normobaric normoxic (20.9% O
2 ) and hypoxic (14,5% O2 ) conditions. The training groups in both conditions were engaged in HHT on the treadmill for 9 weeks. From the 4111 week of the training period. the groups assigned to hypoxic conditions were exposed to normobaric hypoxia. Results: Hypoxic training enhanced citrate synthase activity as well as the protein levels of PGC- 1 a and the mitochondrial respiratory chain complex in the gastrocnemius muscle, when compared to the other 3 groups. Moreover, hypoxic training also elevated the level of expression of mitochondrial fusion-related protein (OPA 1 ) compared to the other groups. Discussion: 1-HIT under not-mobaric hypoxia improved the oxidative capacity of rat gastrocnemius muscles, possibly by increasing the expression of mitochondrial biogenesis and dynamics-related proteins. [ABSTRACT FROM AUTHOR]- Published
- 2022
20. EFFECT OF HEAT STRESS ON DESMIN EXPRESSION IN ATROPHIED SOLEUS MUSCLE.
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SUGIURA, TAKAO, SHIBAGUCHI, TSUBASA, YOSHIHARA, TOSHINORI, YAMAMOTO, YUKI, GOTO, KATSUMASA, NAITO, HISASHI, and YOSHIOKA, TOSHITADA
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- 2010
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21. Effects of cardiac rehabilitation in patients with metabolic syndrome after coronary artery bypass grafting.
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Onishi, Tomo, Shimada, Kazunori, Sunayama, Satoshi, Ohmura, Hirotoshi, Sumide, Takahiro, Masaki, Yoshiyuki, Fukao, Kosuke, Nishitani, Miho, Kume, Atsumi, Sato, Hiroyuki, Naito, Hisashi, Kawai, Sachio, Amano, Atsushi, and Daida, Hiroyuki
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CORONARY artery bypass ,MYOCARDIAL revascularization ,COMPUTER-aided design ,MUSCLE strength - Abstract
Summary: Background: Cardiac rehabilitation (CR) has numerous beneficial effects, including the modification of coronary risk factors and improvement of the prognosis, in patients with coronary artery disease (CAD). Limited data are available regarding the effects of CR on the physical status and risk factors in patients with metabolic syndrome (MetS) after coronary artery bypass grafting (CABG). Methods and results: We enrolled 32 patients with MetS after CABG, who participated in a supervised CR program for 6 months. Metabolic parameters, blood chemistry, exercise tolerance, and muscle strength of the thigh were measured before and after CR. After CR: (1) the body mass index, waist circumference, and fat weight significantly decreased; (2) peak and anaerobic threshold were significantly increased; (3) isokinetic peak torques of knee extensor and flexor muscles significantly increased; (4) metabolic scoring defined by the number of the modified Adult Treatment Panel criteria of the US National Cholesterol Education Program was significantly improved; (5) serum concentration of high-sensitivity C-reactive protein also significantly decreased. Conclusions: These results suggest that CR might be useful for patients with MetS after CABG. [Copyright &y& Elsevier]
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- 2009
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22. EFFECT OF LONG-TERM DIETARY ASTAXANTHIN INTAKE ON SARCOPENIA.
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SHIBAGUCHI, TSUBASA, SUGUIRA, TAKAO, FURUMOTO, TSUKASA, INOUE, KOSHIRO, IIDA, YOSHIHARU, ISOYAMA, TOMOMI, NAITO, HISASHI, GOTO, KATSUMASA, OHMORI, DAIJIRO, and YOSHIOKA, TOSHITADA
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- 2008
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23. QUANTIFYING TIME SPENT IN MODERATE TO VIGOROUS INTENSITY PHYSICAL ACTIVITY VIA STEPPING RATE.
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AYABE, MAKOTO, KUMAHARA, HIDEAKI, AOKI, JUNICHIRO, NAITO, HISASHI, KATAMOTO, SHIZUO, and TANAKA, HIROAKI
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- 2008
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24. RELATIONSHIP BETWEEN OPEN-WATER SWIMMING PERFORMANCE AND AEROBIC CAPACITY.
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KOBAYASHI, IKUMI, AYABE, MAKOTO, SUZUKI, DAICHI, NAITO, HISASHI, and AOKI, JUNICHIRO
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- 2008
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25. Determinants of intramyocellular lipid accumulation after dietary fat loading in non‐obese men
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Sakurai, Yuko, Tamura, Yoshifumi, Takeno, Kageumi, Kumashiro, Naoki, Sato, Fumihiko, Kakehi, Saori, Ikeda, Shinichi, Ogura, Yuji, Saga, Norio, Naito, Hisashi, Katamoto, Shizuo, Fujitani, Yoshio, Hirose, Takahisa, Kawamori, Ryuzo, and Watada, Hirotaka
- Abstract
Aims/Introduction: Accumulation of intramyocellular lipid (IMCL) is associated with insulin resistance. However, the factors affecting the change in IMCL remain to be elucidated. The aim of the present study was to determine the factors that influence the change in IMCL level after high‐fat loading.
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- 2011
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26. Heat stress enhances mTOR signaling after resistance exercise in human skeletal muscle
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Kakigi, Ryo, Naito, Hisashi, Ogura, Yuji, Kobayashi, Hiroyuki, Saga, Norio, Ichinoseki-Sekine, Noriko, Yoshihara, Toshinori, and Katamoto, Shizuo
- Abstract
This study investigated the effect of heat stress (HS) on mammalian target of rapamycin (mTOR) signaling involved in translation initiation after resistance exercise in human skeletal muscle. Eight young male subjects performed four sets of six maximal repetitions of knee extension exercises, with or without HS, in a randomized crossover design. HS was applied to the belly of the vastus lateralis by using a microwave therapy unit prior to and during exercise. Muscle biopsies were taken from the vastus lateralis before, immediately after, and 1 h after exercise. HS significantly increased the phosphorylation of Akt/PKB, mTOR, and ribosomal protein S6 at 1 h after exercise (P< 0.05), and the 4E-BP1 phosphorylation level, which had initially decreased with exercise, had recovered by 1 h after exercise with HS. In addition, the phosphorylation of ribosomal S6 kinase 1 was significantly increased immediately after exercise with HS (P< 0.05). These results indicate that HS enhances mTOR signaling after resistance exercise in human skeletal muscle.
- Published
- 2011
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27. Short-term exercise improves myocardial tolerance to in vivo ischemia-reperfusion in the rat
- Author
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Demirel, Haydar A., Powers, Scott K., Zergeroglu, Murat A., Shanely, R. Andrew, Hamilton, Karyn, Coombes, Jeff, and Naito, Hisashi
- Abstract
These experiments examined the independent effects of short-term exercise and heat stress on myocardial responses during in vivo ischemia-reperfusion (I/R). Female Sprague-Dawley rats (4 mo old) were randomly assigned to one of four experimental groups: 1) control,2) 3 consecutive days of treadmill exercise [60 min/day at 60–70% maximal O2uptake (V˙o2 max)], 3) 5 consecutive days of treadmill exercise (60 min/day at 60–70%V˙o2 max), and 4) whole body heat stress (15 min at 42°C). Twenty-four hours after heat stress or exercise, animals were anesthetized and mechanically ventilated, and the chest was opened by thoracotomy. Coronary occlusion was maintained for 30-min followed by a 30-min period of reperfusion. Compared with control, both heat-stressed animals and exercised animals (3 and 5 days) maintained higher (P< 0.05) left ventricular developed pressure (LVDP), maximum rate of left venticular pressure development (+dP/dt), and maximum rate of left ventricular pressure decline (−dP/dt) at all measurement periods during both ischemia and reperfusion. No differences existed between heat-stressed and exercise groups in LVDP, +dP/dt, and −dP/dtat any time during ischemia or reperfusion. Both heat stress and exercise resulted in an increase (P< 0.05) in the relative levels of left ventricular heat shock protein 72 (HSP72). Furthermore, exercise (3 and 5 days) increased (P< 0.05) myocardial glutathione levels and manganese superoxide dismutase activity. These data indicate that 3–5 consecutive days of exercise improves myocardial contractile performance during in vivo I/R and that this exercise-induced myocardial protection is associated with an increase in both myocardial HSP72 and cardiac antioxidant defenses.
- Published
- 2001
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28. Exercise training increases heat shock protein in skeletal muscles of old rats
- Author
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NAITO, HISASHI, POWERS, SCOTT K., DEMIREL, HAYDAR A., and AOKI, JUNICHIRO
- Abstract
NAITO, H., S. K. POWERS, H. A. DEMIREL, and J. AOKI. Exercise training increases heat shock protein in skeletal muscles of old rats. Med. Sci. Sports Exerc., Vol. 33, No. 5, 2001, pp. 729–734. PurposeThe effects of chronic exercise training on the expression of heat shock protein (HSP) in skeletal muscle of senescent animals are unknown. Therefore, the purpose of this study was to investigate the effects of chronic exercise training on skeletal muscle HSP expression in both young and old rats.
- Published
- 2001
29. Heat stress attenuates skeletal muscle atrophy in hindlimb-unweighted rats
- Author
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Naito, Hisashi, Powers, Scott K., Demirel, Haydar A., Sugiura, Takao, Dodd, Stephen L., and Aoki, Junichiro
- Abstract
This study tested the hypothesis that elevation of heat stress proteins by whole body hyperthermia is associated with a decrease in skeletal muscle atrophy induced by reduced contractile activity (i.e., hindlimb unweighting). Female adult rats (6 mo old) were assigned to one of four experimental groups (n= 10/group): 1) sedentary control (Con), 2) heat stress (Heat), 3) hindlimb unweighting (HLU), or 4) heat stress before hindlimb unweighting (Heat+HLU). Animals in the Heat and Heat+HLU groups were exposed to 60 min of hyperthermia (colonic temperature ∼41.6°C). Six hours after heat stress, both the HLU and Heat+HLU groups were subjected to hindlimb unweighting for 8 days. After hindlimb unweighting, the animals were anesthetized, and the soleus muscles were removed, weighed, and analyzed for protein content and the relative levels of heat shock protein 72 (HSP72). Compared with control and HLU animals, the relative content of HSP72 in the soleus muscle was significantly elevated (P< 0.05) in both the Heat and Heat+HLU animals. Although hindlimb unweighting resulted in muscle atrophy in both the HLU and Heat+HLU animals, the loss of muscle weight and protein content was significantly less (P< 0.05) in the Heat+HLU animals. These data demonstrate that heat stress before hindlimb unweighting can reduce the rate of disuse muscle atrophy. We postulate that HSP70 and/or other stress proteins play a role in the control of muscle atrophy induced by reduced contractile activity.
- Published
- 2000
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30. Exercise training protects against contraction-induced lipid peroxidation in the diaphragm
- Author
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Vincent, Heather K., Powers, Scott K., Demirel, Haydar A., Coombes, Jeff S., and Naito, Hisashi
- Abstract
Endurance exercise training promotes a small but significant increase in antioxidant enzyme activity in the costal diaphragm (DIA) of rodents. It is unclear if these training-induced improvements in muscle antioxidant capacity are large enough to reduce oxidative stress during prolonged contractile activity. To test the hypothesis that training-related increases in DIA antioxidant capacity reduces contraction-induced lipid peroxidation, we exercise trained adult female Sprague-Dawley ( n?=?7) rats on a motor-driven treadmill for 12?weeks at ˜ 75% maximal O
2 consumption (90?min/day). Control animals ( n?=?8) remained sedentary during the same 12-week period. After training, DIA strips from animals in both experimental groups were excised and subjected to an in vitro fatigue contractile protocol in which the muscle was stimulated for 60?min at a frequency of 30?Hz, every 2?s, with a train duration of 330?m. Compared to the controls, endurance training resulted in an increase ( P?0.05) in diaphragmatic non-protein thiols and in the activity of the antioxidant enzyme superoxide dismutase. Following the contractile protocol, lipid peroxidation was significantly lower ( P?0.05) in the trained DIA compared to the controls. These data support the hypothesis that endurance exercise training-induced increases in DIA antioxidant capacity protect the muscle against contractile-related oxidative stress.- Published
- 1999
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31. Exercise-induced alterations in skeletal muscle myosin heavy chain phenotype: dose-response relationship
- Author
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Demirel, Haydar A., Powers, Scott K., Naito, Hisashi, Hughes, Michael, and Coombes, Jeff S.
- Abstract
This study investigated the effects of exercise training duration on the myosin heavy chain (MHC) isoform distribution in rat locomotor muscles. Female Sprague-Dawley rats (120 days old) were assigned to either a sedentary control group or to one of three endurance exercise training groups. Trained animals ran on a treadmill at ∼75% maximal O2uptake for 10 wk (4–5 days/wk) at one of three different exercise durations (30, 60, or 90 min/day). Training resulted in increases (P< 0.05) in citrate synthase activity in the soleus and extensor digitorum longus in both the 60 and 90 min/day duration groups and in the plantaris (Pla) in all three exercise groups. All durations of training resulted in a reduction (P< 0.05) in the percentage of MHCIIband an increase (P< 0.05) in the percentage of MHCIIain the Pla. The magnitude of change in the percentage of MHCIIbin the Pla increased as a function of the training duration. In the extensor digitorum longus, 90 min of daily exercise promoted a decrease (P< 0.05) in percentage of MHCIIband increases (P< 0.05) in the percentages of MHCI, MHCIIa, and MHCIId/x. Finally, training durations ≥60 min resulted in an increase (P< 0.05) in the percentage of MHCIand a concomitant decrease (P< 0.05) in the percentage of MHCIIain the soleus. These results demonstrate that increasing the training duration elevates the magnitude of the fast-to-slow shift in MHC phenotype in rat hindlimb muscles.
- Published
- 1999
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32. Asymptotic behavior of solutions to Eells-Sampson equations near stable harmonic maps
- Author
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Naito, Hisashi
- Published
- 1989
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33. Exercise training reduces myocardial lipid peroxidation following short-term ischemia-reperfusion
- Author
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DEMIREL, HAYDAR A., POWERS, SCOTT K., CAILLAUD, CORINNE, COOMBES, JEFF S., NAITO, HISASHI, FLETCHER, LOUISE A., VRABAS, IANNIS, JESSUP, JAMES V., and JI, LI L.
- Abstract
Exercise training reduces myocardial lipid peroxidation following short-term ischemia-reperfusion.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1211-1216, 1998.
- Published
- 1998
34. Protective effects of acute exercise preconditioning on disuse-induced muscular atrophy in aged muscle: a narrative literature review
- Author
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Yoshihara, Toshinori and Naito, Hisashi
- Abstract
Aging is associated with a progressive loss of skeletal muscle mass and strength, resulting in frailty and lower quality of life in older individuals. At present, a standard of clinical or pharmacological care to prevent the adverse effects of aging does not exist. Determining the mechanism(s) responsible for muscular atrophy in disused aged muscle is a required key step for the development of effective countermeasures. Studies suggest an age-related differential response of genes and signalings to muscle disuse in both rodents and humans, implying the possibility that effective countermeasures to prevent disuse muscle atrophy may be age-specific. Notably, exercise preconditioning can attenuate disuse-induced muscular atrophy in rodent and human skeletal muscles; however, information on age-specific mechanisms of this exercise-induced protection remains limited. This mini-review aimed to summarize the protective effects of acute exercise preconditioning on muscular atrophy in aged muscle and provide potential mechanisms for its preventive effect on skeletal muscle wasting.
- Published
- 2020
- Full Text
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35. Regional brain gray matter volume in world-class artistic gymnasts
- Author
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Fukuo, Makoto, Kamagata, Koji, Kuramochi, Mana, Andica, Christina, Tomita, Hiroyuki, Waki, Hidefumi, Sugano, Hidenori, Tange, Yuichi, Mitsuhashi, Takumi, Uchida, Wataru, Takenaka, Yuki, Hagiwara, Akifumi, Harada, Mutsumi, Goto, Masami, Hori, Masaaki, Aoki, Shigeki, and Naito, Hisashi
- Abstract
The relationship between long-term intensive training and brain plasticity in gymnasts has recently been reported. However, the relationship between abilities in different gymnastic events and brain structural changes has not been explored. This study aimed to evaluate the correlation between world-class gymnasts (WCGs)’ specific abilities in different gymnastics events and their gray matter (GM) volume. Ten right-handed Japanese male WCGs and 10 right-handed gender- and age-matched controls with no history of gymnastic training participated in this study. Whole brain three-dimensional T1-weighted images (magnetization-prepared rapid gradient-echo sequence) with 0.90 mm3voxels were obtained using a 3 T-MRI scanner from each subject. Volume-based morphometry (VolBM) was used to compare GM volume differences between WCGs and controls. We then explored the correlation between specific gymnastic abilities using different gymnastic apparatuses, and GM volume. Significantly higher GM volumes (false discovery rate-corrected p< 0.05) in the inferior parietal lobule, middle temporal gyrus, precentral gyrus, rostral middle frontal gyrus, and superior frontal gyrus were demonstrated in WCGs, compared with controls using VolBM. Moreover, significant positive correlations were observed between brain regions and the difficulty scores for each gymnastic event, for example, rings and inferior parietal lobule and parallel bars and rostral middle frontal gyrus. These results may reflect the neural basis of an outstanding gymnastic ability resulting from brain plasticity in areas associated with spatial perception, vision, working memory, and motor control.
- Published
- 2020
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36. The effects of combined circuit training on muscle size and peak oxygen uptake for elderly women.
- Author
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Ozaki, Hayao and Naito, Hisashi
- Abstract
Purpose: To investigate the effects of combined circuit training on muscle size and peak oxygen uptake for elderly women. Methods: Twelve elderly women were divided into either a low-intensity aerobic exercise group (LOW-Ex) or a high-intensity aerobic exercise group (HIGH-Ex) in random order. Participants performed a combined circuit training consisting of resistance exercise and walking, 3 days per week for 8 weeks. Lower body resistance exercises were based on body mass and upper body resistance exercises performed using an elastic tube. Both groups carried out the same resistance exercise program. Between these resistance exercises, LOW-Ex group performed 40 seconds walking at the previously-determined speed equivalent to 55% VO
2 peak, whereas HIGH-Ex group performed 30 seconds walking at 75% VO2 peak. Results: Body-mass based resistance exercises significantly increased muscle thickness in the anterior aspect of thigh and the relative change was negatively correlated to the absolute value at pre-intervention. Isokinetic knee extension strength also improved by body-mass based resistance exercises and the relative change was negatively correlated to the relative value of isokinetic knee strength to body mass at pre-intervention. Furthermore, two-way repeated measures ANOVA showed that a significant group x time interaction existed in V02peak. V02peak increased only for HIGH-Ex group. [ABSTRACT FROM AUTHOR]- Published
- 2014
37. Effects of different temperature stimuli on the regeneration of injured soleus muscles in rats.
- Author
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Shibaguchi, Tsubasa, Sugiura, Takao, Goto, Katsumasa, Yoshihara, Toshinori, Naito, Hisashi, Ohira, Yoshinobu, and Yoshioka, Toshitada
- Abstract
Purpose: This study was performed to investigate the effects of icing or heat stress on the regeneration of injured rat skeletal muscles. Methods: To induce muscle injury, bupivacaine (BPVC) was injected into soleus muscles of both legs of male Wistar strain rats (9-week-old). Icing (with ice pack, 20 min) was performed immediately after injury. Heat stress (42°C, 30min) was applied 2 days after injury and every other day up to a maximum of 2 weeks during the following recovery periods. Soleus muscle were removed 3 days and 1, 2 and 4 weeks after injury and analyzed by histochemical and biochemical procedures. Results and Discussion: Four weeks after injury, the relative wet weight and protein content of soleus muscle in the heat stress group recovered to control level, but not in BPVC and icing groups. Icing delayed the timing of the reduction in TGF-ß expression and promoted the increase in fibrotic area. However, heat stress induced the early recovery of heat shock protein 72 expression, delayed the timing of the reduction in satellite cell number, and inhibited the increase in fibrotic area. Our data suggest that muscle regeneration after BPVC injection could be promoted by heat stress, but inhibited by icing. [ABSTRACT FROM AUTHOR]
- Published
- 2014
38. The ACTN3 R577X polymorphism in Japanese recreational cyclists.
- Author
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Saga, Norio, Naito, Hisashi, Sekine, Noriko, Katamoto, Shizuo, and Kawal, Sachio
- Abstract
Introduction: This study compared the distribution of the α-actinin-3 (ACTN3) gene R577X polymorphism between Japanese recreational cyclists and untrained adults. Methods: Forty-nine recreational cyclists (age, 41 ± 11 y) and thirty-eight untrained adults (age, 43 ± 13 y) participated in this study and metabolic syndrome risk factors were measured by blood samples. Genomic DNA was prepared from blood samples. The ACTN3 R577X polymorphism was genotyped using real-time polymerase chain reaction assays with TaqMan probes and a sequence detector. Twelve relational cyclists in them performed a maximal incremental cycling exercise test to determine their maximal oxygen uptake (V02) and the lactate threshold (LT) test Results: There was no statistical difference in genotypes (RR, RX, XX) frequencies between recreational cyclists (14, 57, 29%) and untrained adults (20, 35, 22%). In the V0
2 , LT and blood makers, there were no differences among the genotypes in recreational cyclist. Conclusion: The results of this study suggest that the ACTN3 genotype does not affect their aerobic capacity and metabolic syndrome risk factors in Japaneserecreational cyclists. [ABSTRACT FROM AUTHOR]- Published
- 2011
39. Autolysti of ralpain 1 and 2 during hindlimb unloading was attenuated by intennittent reloading with heat stress in rat soleus muscle.
- Author
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Yoshihara, Toshinori, Sugiura, Takao, and Naito, Hisashi
- Abstract
Purpose: To examine the effect of intermittent reloading with heat stress on autolysis of calpain 1 and 2 in atrophied rat soleus muscle Methods: Forty male Wistar rats (10wks of age, 261. 7± 1.17 g) were randomly divided into four groups: control (CON, n=1O), hindlimb unloading (HU, n=1O), hindlimb unloading with intermittent reloading (IR, n=1O), hindlimb unloading with intermittent reloading and heat stress (IR+H, n=1O). The HU, IR and IR+H group were unloaded for 7 days. IR and IR+H group were released from unweighting for 1 h every second day. During this time, IR+H group was placed in a heat chamber for 30 min (41.5-42°C). After 7days unloading, soleus muscle were removed and analyzed. Results and Discussions: Seven-days unloading resulted in a 31% reduction in the soleus muscle mass, but only IR+H significantly prevented the reduction (CON; 168.2±6.7, HU; 116.3±3.7, IR; 121.0±3.7, IR+H; 131.1±2.4 mg). Autolyzed form of calpain 2 (HU; 267, IR; 236 and IR+H; 105% of CON) and ubiquitinated protein (HU; 164, IR; 140 and IR+H; 112% of CON) in particulate fraction was significantly increased in HU, but also IR+H significantly prevented the increase. Calpain plays a role in a release of myofibrillar protein from the sarcomere, and the released proteins are degradated by ubiquitin-proteasome system. Therefore, these data indicate that inhibition of calpain autolysis by the intermittent reloading with heat stress could be effective to prevent the muscle atrophy. [ABSTRACT FROM AUTHOR]
- Published
- 2011
40. Fibertype-specific expression of alpha-actinin3 protein in rat diaphragm after 12-h mechanical ventilation.
- Author
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Chinoseki-Sekine, Noriko, Yoshihara, Toshinori, Sugiura, Takao, and Naito, Hisashi
- Abstract
Purpose: To examine the effects of 12-h of mechanical ventilation (MV) on fibertype-specific expression of alpha-actinin3 protein in rat diaphragm. Methods: Adult Wistar rats were randomly divided into either a control (n=8) or a 12-h of MV (n=8) group. Mechanically ventilated animals were anesthetized, tracheostomized, and ventilated with 21% 0 2 for 12 hours. The carotid artery was cannulated for measurement of arterial blood pressure, pH, and blood gases. The jugular vein was also cannulated for the infusion of saline and pentobarbital. Animals in the control group were acutely anesthetized but were not exposed to MV. After the treatment, diaphragms were removed and immunohistochemical detection of muscle fiber type (Type I, Type Ila and Type Ilx+b) and alpha-actinin3 expression were performed. Results and Discussion: MV resulted in a decrease of the cross-sectional area (CSA) by 16.5% (P < 0.05) and area percentage in Type Ilx+b fiber (P < 0.05). Fiber composition was not changed after MV. There was no alpha-actinin3 positive Type I fiber in all animals. In contrast, alpha-actinin3 expressed in all Type Ilx+b fibers. Interestingly, alpha-actinin3 expression was observed in 14% of Type Ila fibers, and this percentage did not change regardless of MV. Our results demonstrated that 1) selective atrophy of the Type Ilx+b fiber was caused by 12-h of MV in rat diaphragm, and 2) expression pattern of alpha-actinin3 protein was not affected by 12-h ofMV [ABSTRACT FROM AUTHOR]
- Published
- 2011
41. Effect of the differences in exercise intensity of resistance training on carotid arterial compliance.
- Author
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Ozaki, Hayao, Naito, Hisashi, and Katamoto, Shizuo
- Abstract
Purpose: High-intensity resistance training generally reduces central arterial compliance in young subjects. However, the effect of low-intensity resistance training with blood flow restriction (BFR) on carotid arterial compliance has not yet been explored. We investigated the effect of differences in exercise intensity of resistance training on carotid arterial compliance. Methods: Nineteen healthy young men, aged 22-32 years, were randomly divided into either low-intensity resistance training with BFR group (LT-BFR; 30%1RM, 4 sets, 75 reps [30-15-15-15]) or high-intensity resistance training group (HT; 75%1RM, 3 sets, 30 reps [10-10-10]). They performed free weight bench press exercise, 3 days per week, for 6 weeks. The LT-BFR group wore pressure cuff belts on both arms during training (external compression: 160mrnHg). Results&Discussion: MRI-measured pectoralis major muscle cross-sectional area and 1RM bench press strength significantly increased in both training groups after the training (p<0.05). Carotid arterial compliance was reduced (p<0.05) in only the HT group. Systolic blood pressure in thigh during exercise significantly were higher for HT group than LT-BFR group (p<0.05). The present study suggested that low-intensity resistance training with blood flow restriction does not influence carotid arterial compliance. [ABSTRACT FROM AUTHOR]
- Published
- 2011
42. ACTN3 Gene and Skeletal Muscle.
- Author
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Naito, Hisashi
- Abstract
The alpha-actinin is actin-binding protein. In skeletal muscle, alpha-actinins-2 (ACTN2) and alpha-actinins-3 (ACTN3) isoforms are playing an important role as structural component of the Z-lines that anchor the actin-containing thin filaments and maintain the spatial relationship between myofilaments. ACTN3 is expressed only in type II muscle fibers while the ACTN2 is found in all muscle fibers. A common nonsense mutation in ACTN3 (R577X) results in ACTN3 deficiency that appears to be non-pathogenic and it is postulated that ACTN2 compensates for the deficiency. Therefore, it is hypothesized that ACTN3 genotype (RR, RX, XX) may influence variation in muscle function in humans and many studies have confirmed that the presence of the ACTN3 protein, or RR genotype is associated with greater success in activities requiring sprint or power performance. In contrast to the findings in power athletes, it is controversial that a lack of ACTN3 protein, or XX genotype is beneficial to endurance athletes. And associations of ACTN3 genotype with trainability, exercise-induced muscle damage and age-related changes of muscular function have been studied. However, these results are different among the studies because of differences of human race, age, sex, and physical activity level and so on. To clarify roles of ACTN3 genotype on skeletal muscle functions and their mechanisms, further studies with genetically modified animal models would be useful. [ABSTRACT FROM AUTHOR]
- Published
- 2011
43. Hormonal responses following eccentric exercise with and without heat preconditioning and damage experience.
- Author
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SAGA, Norio, NAITO, Hisashi, and KATAMOTO, Shizuo
- Abstract
An abstract of the study "Hormonal responses following eccentric exercise with and without heat preconditioning and damage experience," by Norio Saga, Hisashi Naito, and Shizuo Katamoto, is presented.
- Published
- 2010
44. Effects of the combination of heat stress and dietary antioxidant intake on the recovery of atrophied muscle.
- Author
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SHIBAGUCHI, Tsubasa, SUGIURA, Takao, GOTO, Katsumasa, NAITO, Hisashi, and YOSHIOKA, Toshitada
- Abstract
An abstract of the study "Effects of the combination of heat stress and dietary antioxidant intake on the recovery of atrophied muscle," by Tsubasa Shibaguchi and colleagues, is presented.
- Published
- 2010
45. The expressions of alpha-actinin isoforms in rat damaged muscle.
- Author
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KAKIGI, Ryo, NAITO, Hisashi, OGURA, Yuji, FUKA1, Yuto, YOSHIHARA, Toshinori, and KATAMOTO, Shizuo
- Abstract
An abstract of the study "The expressions of alpha-actinin isoforms in rat damaged muscle," by Ryo Kakigi and colleagues is presented.
- Published
- 2010
46. Prevention of sarcopenia by antioxidants intake.
- Author
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SUGIURA, Takao, SHIBAGUCHI, Tsubasa, NAITO, Hisashi, GOTO, Katsumasa, and YOSHIOKA, Toshitada
- Abstract
An abstract of the article "Prevention of sarcopenia by antioxidants intake," by Takao Sugiura and colleagues is presented.
- Published
- 2010
47. Whey Peptide HW-3 enhances the recovery from muscle atrophy in rat.
- Author
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ICHINOSEKI-SEKINE, Noriko, KAKIGI, Ryo, OGURA, Yuji, MIURA, Susumu, and NAITO, Hisashi
- Abstract
An abstract of the study "Whey Peptide HW-3 enhances the recovery from muscle atrophy in rat," by Hisashi Naito and colleagues is presented.
- Published
- 2009
48. Prevention of skeletal muscle atrophy by the combination of intermittent reloading and heat stress.
- Author
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SHIBAGUCH1, Tsubasa, SUGIURA, Takao, GOTO, Katsumasa, YOSHIHARA, Toshinori, NAITO, Hisashi, OHMORI, Daijiro, and YOSHIOKA, Toshitada
- Abstract
An abstract of the study "Prevention of skeletal muscle atrophy by the combination of intermittent reloading and heat stress," by Tsubasa Shibaguchi and colleagues is presented.
- Published
- 2009
49. The effects of heat stress on skeletal muscle atrophy as seen from the expression of cytoskeletal protein.
- Author
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SUGIURA, Takao, SHIBAGUCHI, Tsubasa, GOTO, Katsumasa, YOSHIHARA, Toshinori, NAITO, Hisashi, and YOSHIOKA, Toshitada
- Abstract
An abstract of the study "The effects of heat stress on skeletal muscle atrophy as seen from the expression of cytoskeletal protein," by Takao Sugiura and colleagues is presented.
- Published
- 2009
50. Effects of heat stress on mTOR signaling pathway in rat skeletal muscle.
- Author
-
KAKIGI, Ryo, NAITO, Hisashi, OGURA, Yuji, and KATAMOTO, Shizuo
- Abstract
An abstract of the study "Effects of heat stress on mTOR signaling pathway in rat skeletal muscle," by Ryo Kakigi and colleagues is presented.
- Published
- 2009
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