Experimental Physiology最新文献

{"title":"A slow burn: Revisiting cross-adaptation through long-term heat acclimation.","authors":"Elliott J Jenkins, Michael Stembridge","doi":"10.1113/EP092883","DOIUrl":"https://doi.org/10.1113/EP092883","url":null,"abstract":"","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144179971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exercise transcutaneous oxygen pressure measurement: From a small research field to a worldwide community clinical practice.","authors":"Marjolaine Talbot, Adelaïde Guézais, Guillaume Mahé","doi":"10.1113/EP092877","DOIUrl":"https://doi.org/10.1113/EP092877","url":null,"abstract":"","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144157526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The ultimate exercise countermeasure for long-duration spaceflight?","authors":"Donald E Watenpaugh, Alan R Hargens","doi":"10.1113/EP092820","DOIUrl":"https://doi.org/10.1113/EP092820","url":null,"abstract":"","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144157528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chronic and acute mediators of passive viscoelasticity in human skeletal muscle fibres.","authors":"Grace E Privett, Austin W Ricci, Karen Wiedenfeld Needham, Damien M Callahan","doi":"10.1113/EP092361","DOIUrl":"https://doi.org/10.1113/EP092361","url":null,"abstract":"<p><p>The cellular viscoelastic modulus in skeletal muscle tissue responds dynamically to chronic stressors, such as age and exercise. Passive tissue mechanics can also be sensitive to acute stimuli, such as mechanical loading and/or activation-induced muscle fatigue. These insights are largely derived from preclinical studies of age and acute muscle activation. Therefore, we sought to understand the relative responsiveness of muscle cellular passive mechanics to chronic (resistance training) and acute (exercise-induced muscle fatigue) stressors in healthy young males and females categorized as 'resistance trained' or 'untrained'. We measured passive mechanics to test the hypothesis that Young's modulus and stress would be greater in fibres from trained versus untrained participants and that both would be reduced following fatigue. We also assessed the translation of these findings to composite tissue in a subset of volunteers where muscle tissue bundles, containing both fibres and extracellular matrix, were analysed in addition to single fibres. We found that resistance-trained individuals demonstrated enhanced passive elastic and viscous modulus compared with non-trained individuals. We also report reductions in passive mechanical measures following fatiguing exercise. Surprisingly, both chronic and acute effectors of passive mechanics were observed in muscle fibres only from males, whereas females showed a more variable response across conditions. Last, we provide preliminary evidence supporting the translation of per-individual cellular differences to the tissue level. Together, these data suggest that males respond more dynamically to acute and chronic stressors of muscle tissue mechanics, potentially linking cellular response and sex-dependent differences in functional outcomes across the lifespan.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144150031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the respiratory efficacy of combined chronic glucocorticoid and antioxidant interventions in the mdx mouse: The PREDNAC trial.","authors":"Michael N Maxwell, Ben T Murphy, Fiona B McDonald, Ken D O'Halloran","doi":"10.1113/EP092491","DOIUrl":"https://doi.org/10.1113/EP092491","url":null,"abstract":"<p><p>Duchenne muscular dystrophy (DMD) is characterized by respiratory muscle injury and weakness, ultimately leading to respiratory failure. Impaired respiratory muscle performance, fibrosis and inflammation in early disease are evident in the dystrophin-deficient mdx mouse model of DMD. Prednisone or similar treatment is the current standard of care for DMD and exerts its benefits via an anti-inflammatory action, but chronic treatment is associated with side-effects. A recent study demonstrated improved function in mdx limb muscle with weekly glucocorticoid treatment compared with daily treatment. Herein, we investigated the effect of weekly α-methylprednisolone (PRED) treatment alone and the effect of PRED in combination with daily intake of the antioxidant N-acetyl cysteine, NAC (PREDNAC) on respiratory performance. One-month-old male mdx mice received PRED (0.8 mg/kg methylprednisolone i.p. weekly) or PREDNAC (0.8 mg/kg methylprednisolone i.p. weekly and 1% NAC in drinking water daily) for 3 months. At 4 months of age, conscious breathing was measured in vivo by whole-body plethysmography. Under urethane general anaesthesia, respiratory EMG and inspiratory pressure were measured at baseline and during maximal activity. The intrinsic force-generating capacity of the diaphragm was determined ex vivo. Neither PRED nor PREDNAC influenced breathing or diaphragm force-generating capacity in mdx mice. There was a significant increase in diaphragm and parasternal EMG activity, but inspiratory pressure was unchanged with treatment. We conclude that neither PRED nor PREDNAC has a major beneficial effect on respiratory system performance in the mdx mouse model of DMD. Weekly administration of glucocorticoids is inadequate to protect respiratory performance in mdx mice, which might reflect the higher duty cycle of respiratory muscles compared with limb muscles.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144150032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving coordination, proprioception, balance and motor proficiency in Down syndrome with developmental games.","authors":"Alireza Rezaee, Hasan Daneshmandi, Hesam Ramezanzade, Sahar Mohammadzadeh, Mert Kurnaz, Mustafa Altınkök","doi":"10.1113/EP092739","DOIUrl":"https://doi.org/10.1113/EP092739","url":null,"abstract":"<p><p>This study aimed to investigate the impact of corrective-developmental games on proprioception, coordination, balance and motor proficiency in individuals with Down syndrome. The current quasi-experimental study with pre-test and post-test design explores the impact of corrective-developmental games (fine-gross motor skill games and univariate-multivariate games) on the proprioception, coordination, balance and motor proficiency of individuals with Down syndrome. The research sample comprises 50 individuals with Down syndrome, with an average age of 17.38 years, divided into two groups: intervention (13 men and 13 women) and control (12 men and 12 women). After the pre-test, the intervention group participated in a series of games, including fine-gross games and univariate-multivariate games, for 8 weeks (24 1-h sessions in total). Mid-test and post-test were conducted after 4 and 8 weeks, respectively. To assess balance, the Stork test (test-retest reliability: 0.59), Sharpened Romberg test (reliability: 0.76-0.91) and Y Balance test (reliability: 0.84-0.87) were used. The Purdue Pegboard test and knee position sense with a goniometer (open and closed eyes) evaluated eye-hand coordination and sense of position. The Bruininks-Oseretsky test (retest coefficient: 0.78-0.86) measured motor proficiency. Repeated measures ANOVA revealed significant improvements in the intervention group for static balance (Stork test, P = 0.001), dynamic balance (Y test, P = 0.001), position sense (open eyes: P = 0.001, closed eyes: P = 0.001), two-hand coordination (P = 0.001), preferred hand coordination (P = 0.001), gross motor proficiency (P = 0.001), upper limb coordination (P = 0.001) and total motor proficiency (P = 0.001). The intervention group significantly outperformed the control group post-intervention on all measures except the Stork test and fine motor proficiency. The findings of this research confirm the beneficial effect of games-based interventions on motor fitness and corrective-developmental indicators in Down syndrome. Future studies should investigate the long-term impact on daily life activities and generalizability to similar populations. The results have potential implications for designing effective interventions to enhance motor skills in individuals with Down syndrome.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144119233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"To Mars through LEO: How commercial space travel will change exploration-enabling research.","authors":"Christopher Puhl, Michail Magkos","doi":"10.1113/EP092422","DOIUrl":"https://doi.org/10.1113/EP092422","url":null,"abstract":"","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144092786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chronic intermittent hypoxia-mediated cognitive dysfunction in ovariectomized rats.","authors":"Emily C Cheung, Joan B Escobar, Bridget R Alber, Caitlin Ribeiro, Ishan Abdullah, Grant Kowalik, Jeannette Rodriguez, Grey Harral, Makeda Melkie, Aman Gill, John T Ketzenberger, John Bethea, Vsevolod Y Polotsky, Vivek Jain, Kathryn Schunke, Matthew W Kay, David Mendelowitz","doi":"10.1113/EP092018","DOIUrl":"https://doi.org/10.1113/EP092018","url":null,"abstract":"<p><p>Obstructive sleep apnoea (OSA) is a prevalent cardiorespiratory disorder associated with significant neurocognitive consequences. Despite the higher prevalence of OSA in men, there is a strong association between OSA and Alzheimer's disease (AD), which disproportionately affects women. This study aimed to investigate the impact of chronic intermittent hypoxia (CIH), a hallmark of OSA, on cognitive function and AD markers in ovariectomized, female rats. At 8 weeks of age, 16 Sprague-Dawley rats underwent ovariectomy and were exposed to CIH for 26 weeks. Cognitive function was assessed using the Morris water maze, revealing significant deficits in spatial learning (P < 0.0001) and memory (P = 0.008) in CIH-exposed rats, compared to controls. Analysis of hippocampal tissue showed increased total tau protein (P = 0.0078), indicative of AD pathology. Additionally, CIH-exposed rats exhibited respiratory dysfunction characterized by increased frequency of apnoeas (P = 0.0328). These findings provide preclinical evidence of the association between OSA, cognitive decline and AD pathology in females, emphasizing the importance of sex-specific research in understanding and addressing these pathophysiological interconnections.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144101698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cerebrovascular pulsatility following long duration spaceflight is associated with changes in pulse pressure and carotid artery stiffness.","authors":"Roxanne Fournier, Danielle K Greaves, J Kevin Shoemaker, Philippe Arbeille, Richard L Hughson, Andrew D Robertson","doi":"10.1113/EP092272","DOIUrl":"https://doi.org/10.1113/EP092272","url":null,"abstract":"<p><p>Central artery stiffening increases the haemodynamic pulsations transmitted downstream towards target organs, including the brain. While recent evidence suggests that long duration spaceflight is associated with reduced common carotid artery (CCA) distensibility, cerebrovascular pulsatility has not been extensively characterized in astronauts. This study investigated changes in pulsatility from pre-flight to after 6 months in space, using a secondary analysis of data from four separate experiments. Middle cerebral artery blood velocity (MCAv) was measured during supine rest in 27 astronauts (20 men, 7 women). In subsets of this cohort, we measured CCA distensibility and β stiffness (n = 20), and CCA wave intensity (n = 12). The overall increase in MCAv pulsatility index (PI_mca) from pre-flight to post-flight was not significant (0.73 ± 0.12 vs. 0.77 ± 0.11, P = 0.060, partial η² = 0.13). However, individual changes in PI_mca were directly associated with changes in estimated aortic pulse pressure (r = 0.51, P = 0.007) and β stiffness (r = 0.54, P = 0.015), and inversely associated with changes in distensibility (r = -0.62, P = 0.003), in separate bivariate analyses. Wave intensity analysis suggested a reduction in normalized wave reflection (P = 0.07), and that forward compression wave amplitude was directly related to PI_mca (r = 0.64, P = 0.025). These findings suggest that PI_mca in the days immediately following spaceflight is a function of lower carotid distensibility, highlighting the interplay between arterial stiffness and cerebrovascular pulsatility.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144101694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrative cardiovascular dose-response to graded lower-body negative pressure.","authors":"Richard S Whittle, Nathan Keller, Eric A Hall, Safiyya Patanam, Bonnie J Dunbar, Ana Diaz-Artiles","doi":"10.1113/EP092483","DOIUrl":"https://doi.org/10.1113/EP092483","url":null,"abstract":"<p><p>Lower-body negative pressure (LBNP) has been posited as a potential spaceflight countermeasure to counteract the physiological deconditioning related to fluid shifts in microgravity. However, open questions remain regarding the magnitude of LBNP that should be applied. We systematically characterized the cardiovascular effects of LBNP and quantified the effect size of varied LBNP doses across different parts of the cardiovascular system. Twenty-four subjects (12 male and 12 female) were exposed to graded LBNP, increasing from 0 to -50 mmHg in 10 mmHg increments, in both supine (0°) and 15° head-down tilt postures. At each pressure level, subjects first underwent a 6 min stabilization period to reach a steady-state cardiovascular response. We then assessed a wide range of variables, including those related to the systemic circulation, cardiovascular control, and haemodynamics of the eyes and neck. Building on the experimental data, dose-response curves were constructed using a Bayesian multivariate hierarchical modelling framework to quantify the effect size of every variable considered when subjected to LBNP. The methodology allows direct comparison of the variables and the underlying structural relationships between them. Furthermore, we demonstrated the potential for LBNP to reduce jugular venous flow stagnation, which is considered one of the major health risks during human spaceflight. The dose-response curves and effect sizes generated from this research effort establish the most comprehensive framework available to date that characterizes physiological responses to LBNP. These results directly inform the development of countermeasures to mitigate the negative effects of spaceflight, including cardiovascular deconditioning, spaceflight-associated neuro-ocular syndrome and venous thromboembolism events.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144076528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}