Journal of applied physiology最新文献

{"title":"Technological advancements in sports: balancing innovation with the preservation of athlete authenticity.","authors":"Hiago L R Souza, Moacir Marocolo","doi":"10.1152/japplphysiol.00343.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00343.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technology revolution or evolution: track spikes and pacing lights in perspective.","authors":"Victor Rodrigo-Carranza, Montgomery Bertschy, Wouter Hoogkamer","doi":"10.1152/japplphysiol.00413.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00413.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The new challenge in elite sport will be balancing technological progress with sports integrity.","authors":"Géssyca Tolomeu de Oliveira, Renato Melo Ferreira, Everton Rocha Soares, Mário Antônio de Moura Simim, Moacir Marocolo","doi":"10.1152/japplphysiol.00402.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00402.2024","url":null,"abstract":"","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanics of human locomotion in the wind.","authors":"Raphael M Mesquita, Patrick A Willems, Giovanna Catavitello, Giuseppe Gibertini, Valentina Natalucci, Francesco Luciano, Alberto Enrico Minetti, Gaspare Pavei, Arthur H Dewolf","doi":"10.1152/japplphysiol.00253.2024","DOIUrl":"10.1152/japplphysiol.00253.2024","url":null,"abstract":"<p><p>In laboratory settings, human locomotion encounters minimal opposition from air resistance. However, moving in nature often requires overcoming airflow. Here, the drag force exerted on the body by different headwind or tailwind speeds (between 0 and 15 m·s^-1) was measured during walking at 1.5 m·s^-1 and running at 4 m·s^-1. To our knowledge, the biomechanical effect of drag in human locomotion has only been evaluated by simulations. Data were collected on eight male subjects using an instrumented treadmill placed in a wind tunnel. From the ground reaction forces, the drag and external work done to overcome wind resistance and to sustain the motion of the center of mass of the body were measured. Drag increased with wind speed: a 15 m·s^-1 headwind exerted a drag of ∼60 N in walking and ∼50 N in running. The same tailwind exerted -55 N of drag in both gaits. At this wind speed, the work done to overcome the airflow represented ∼80% of the external work in walking and ∼50% in running. Furthermore, in the presence of fast wind speeds, subjects altered their drag area (<i>C</i>_d<i>A</i>) by adapting their posture to limit the increase in air friction. Moving in the wind modified the ratio between positive and negative external work performed. The modifications observed when moving with a head- or tailwind have been compared with moving uphill or downhill. The present findings may have implications for optimizing aerodynamic performance in competitive running, whether in sprints or marathons.<b>NEW & NOTEWORTHY</b> This is the first study to assess the biomechanical adaptations to a wide range of wind speeds inside a wind tunnel. Humans increase their mechanical work and alter their drag area (<i>C</i>_d<i>A</i>) by adapting their posture when walking and running against increasing head and tailwinds. The observed drag force applied to the subject is different between walking and running at similar headwind speeds.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141723702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eccentric contraction increases hydrogen peroxide levels and alters gene expression through Nox2 in skeletal muscle of male mice.","authors":"Ryotaro Kano, Tatsuya Kusano, Reo Takeda, Hideki Shirakawa, David C Poole, Yutaka Kano, Daisuke Hoshino","doi":"10.1152/japplphysiol.00335.2024","DOIUrl":"10.1152/japplphysiol.00335.2024","url":null,"abstract":"<p><p>Hydrogen peroxide (H₂O₂) is one of the key signaling factors regulating skeletal muscle adaptation to muscle contractions. Eccentric (ECC) and concentric (CONC) contractions drive different muscle adaptations with ECC resulting in greater changes. The present investigation tested the hypothesis that ECC produces higher cytosolic and mitochondrial H₂O₂ concentrations [H₂O₂] and alters gene expression more than CONC. Cytosolic and mitochondrial H₂O₂-sensitive fluorescent proteins, HyPer7 and MLS-HyPer7, were expressed in the anterior tibialis muscle of C57BL6J male mice. Before and for 60 min after either CONC or ECC (100 Hz, 50 contractions), [H₂O₂]_cyto and [H₂O₂]_mito were measured by in vivo fluorescence microscopy. RNA sequencing was performed in control (noncontracted), CONC, and ECC muscles to identify genes impacted by the contractions. [H₂O₂]_cyto immediately after ECC was greater than after CONC (CONC: +6%, ECC: +11% vs. rest, <i>P</i> < 0.05) and remained higher for at least 60 min into recovery. In contrast, the elevation of [H₂O₂]_mito was independent of the contraction modes (time; <i>P</i> < 0.0042, contraction mode; <i>P</i> = 0.4965). The impact of ECC on [H₂O₂]_cyto was abolished by NADPH oxidase 2 (Nox2) inhibition (GSK2795039). Differentially expressed genes were not present after CONC or ECC + GSK but were found after ECC and were enriched for vascular development and apoptosis-related genes, among others. In conclusion, in mouse anterior tibialis, ECC, but not CONC, evokes a pronounced cytosolic H₂O₂ response, caused by Nox2, that is mechanistically linked to gene expression modifications.<b>NEW & NOTEWORTHY</b> This in vivo model successfully characterized the effects of eccentric (ECC) and concentric (CONC) contractions on cytosolic and mitochondrial [H₂O₂] in mouse skeletal muscle. Compared with CONC, ECC induced higher and more sustained [H₂O₂]_cyto-an effect that was abolished by Nox2 inhibition. ECC-induced [H₂O₂]_cyto elevations were requisite for altered gene expression.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141758844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal hematocrit theory: a review.","authors":"Michal Sitina, Heiko Stark, Stefan Schuster","doi":"10.1152/japplphysiol.00034.2024","DOIUrl":"10.1152/japplphysiol.00034.2024","url":null,"abstract":"<p><p>In humans and many animals, a trade-off between a sufficiently high concentration of erythrocytes (hematocrit) to bind oxygen and sufficiently low blood viscosity to allow rapid blood flow has been achieved during evolution. The optimal value lies between the extreme cases of pure blood plasma, which cannot practically transport any oxygen, and 100% hematocrit, which would imply very slow blood flow or none at all. As oxygen delivery to tissues is the main task of the cardiovascular system, it is reasonable to expect that maximum oxygen delivery has been achieved during evolution. Optimal hematocrit theory, based on this optimality principle, has been successful in predicting hematocrit values of about 0.3-0.5, which are indeed observed in the systemic circulation of humans and many animal species. Similarly, the theory can explain why a hematocrit higher than normal, ranging from 0.5 to 0.7, can promote better exertional performance. Here, we present a review of theoretical approaches to the calculation of the optimal hematocrit value under different conditions and discuss them in a broad physiological context. Several physiological and medical implications are outlined, for example, in view of blood doping, temperature adaptation, dehydration, and life at high altitudes.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141175557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flow interruption compared to forced oscillatory maneuvers and esophageal balloon/pneumotachography for measurement of respiratory resistance in the horse.","authors":"Melissa R Mazan, Christopher Simotas, Thomas Coons, Brian Barrow, Daniela Bedenice, Jill Minuto, Kristen Wendell, Edward F Deveney","doi":"10.1152/japplphysiol.00213.2024","DOIUrl":"10.1152/japplphysiol.00213.2024","url":null,"abstract":"<p><p>Pulmonary function testing is critical to the diagnosis of equine asthma (EA), an important cause of respiratory disease in the horse, but its clinical use has remained elusive, unfortunately, due to the complexity of reference methods, esophageal balloon/pneumotachography (EBP), and forced oscillatory mechanics (FOM), so we sought a noninvasive, portable method for use in horses through rapid interruption of airflow for equilibration of alveolar pressure with proximal airway pressure, termed flow interruption (FI). Resistance (<i>R</i>_INT) was computed as the relationship between the change in pressure at the nose before and immediately after interruption and flow immediately before interruption. A pilot study in five healthy university-owned animals using EBP and FI showed good correspondence between the two methods: <i>R</i>_INT (0.33 ± 0.05 cmH₂O/L/s) and <i>R</i>_L (0.31 ± 0.06 cmH₂O/L/s). In two separate populations of client-owned horses, with random assignment of methods to FI versus EBP (<i>n</i> = 8), <i>R</i>_INT showed good correlation with <i>R</i>_L in horses (<i>r</i>_s = 0.995, <i>P</i> = 0.0002) and accords with <i>R</i>_L, with no significant difference between <i>R</i>_INT and <i>R</i>_L. Using FOM (<i>n</i> = 12), <i>R</i>_INT (0.67 ± 0.31 cmH₂O/L/s) has good correlation with <i>R</i>_RS measured with FOM (<i>r</i> = 0.834, <i>P</i> = 0.0001), but is consistently smaller than <i>R</i>_RS (0.74 ± 0.33 cmH₂O/L/s). Histamine bronchoprovocation (HBP) was performed in a subset of these horses: FI classified one horse in six as less reactive than did EBP, and FI classified one horse in seven as less reactive than did FOM.<b>NEW & NOTEWORTHY</b> We developed and document for the first time the use of flow interruption for the rapid and noninvasive measurement of resistance in equine patients and demonstrated short- and long-term stability and accuracy in comparison with the reference methods.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141457089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Release of ATP in the lung evoked by inhalation of irritant gases in rats.","authors":"Nai-Ju Chan, Yueh-Yin Chen, Chun-Chun Hsu, You Shuei Lin, Maxwell Zakeri, Seonwook Kim, Mehdi Khosravi, Lu-Yuan Lee","doi":"10.1152/japplphysiol.00137.2024","DOIUrl":"10.1152/japplphysiol.00137.2024","url":null,"abstract":"<p><p>Adenosine triphosphate (ATP) can be released into the extracellular milieu from various types of cells in response to a wide range of physical or chemical stresses. In the respiratory tract, extracellular ATP is recognized as an important signal molecule and trigger of airway inflammation. Chlorine (Cl₂), sulfur dioxide (SO₂), and ammonia (NH₃) are potent irritant gases and common industrial air pollutants due to their widespread uses as chemical agents. This study was carried out to determine if acute inhalation challenges of these irritant gases, at the concentration and duration simulating the accidental exposures to these chemical gases in industrial operations, triggered the release of ATP in the rat respiratory tract; and if so, whether the level of ATP in bronchoalveolar lavage fluid (BALF) evoked by inhalation challenge of a given irritant gas was elevated by chronic allergic airway inflammation. Our results showed: <i>1</i>) inhalation of these irritant gases caused significant increases in the ATP level in BALF, and the magnitude of evoked ATP release was in the order of Cl₂ > SO₂ > NH₃. <i>2</i>) Chronic airway inflammation induced by ovalbumin-sensitization markedly elevated the ATP level in BALF during baseline (breathing room air) but did not potentiate the release of ATP in the lung triggered by inhalation challenges of these irritant gases. These findings suggested a possible involvement of the ATP release in the lung in the regulation of overall airway responses to acute inhalation of irritant gases and the pathogenesis of chronic allergic airway inflammation.<b>NEW & NOTEWORTHY</b> Extracellular adenosine triphosphate (ATP) is a contributing factor and signaling molecule of airway inflammation. This study demonstrated for the first time that the ATP release in the lung was markedly elevated after acute inhalation challenges of three common industrial air pollutants; the order of the response magnitude was chlorine > sulfur dioxide > ammonia. These findings provided new information and improved our understanding of the adverse pulmonary effects caused by accidental inhalation exposures to these irritant gases.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141457091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lifelong physiology of a former marathon world-record holder: the pros and cons of extreme cardiac remodeling.","authors":"Stephen J Foulkes, Mark J Haykowsky, Peter M Kistler, Glenn K McConell, Scott Trappe, Mark Hargreaves, David L Costill, Andre La Gerche","doi":"10.1152/japplphysiol.00070.2024","DOIUrl":"10.1152/japplphysiol.00070.2024","url":null,"abstract":"<p><p>In a 77-year-old former world-record-holding male marathoner (2:08:33.6), this study sought to investigate the impact of lifelong intensive endurance exercise on cardiac structure, function, and the trajectory of functional capacity (determined by maximal oxygen consumption, V̇o_2max) throughout the adult lifespan. As a competitive runner, our athlete (DC) reported performing up to 150-300 miles/wk of moderate-to-vigorous exercise and sustained 10-15 h/wk of endurance exercise after retirement from competition. DC underwent maximal cardiopulmonary exercise testing in 1970 (aged 27 yr), 1991 (aged 49 yr), and 2020 (aged 77 yr) to determine V̇o_2max. At his evaluation in 2020, DC also underwent comprehensive cardiac assessments including resting echocardiography, and resting and exercise cardiac magnetic resonance to quantify cardiac structure and function at rest and during peak supine exercise. DC's V̇o_2max showed minimal change from 27 yr (69.7 mL/kg/min) to 49 yr (68.1 mL/kg/min), although it eventually declined by 36% by the age of 77 yr (43.6 mL/kg/min). DC's V̇o_2max at 77 yr, was equivalent to the 50th percentile for healthy 20- to 29-yr-old males and 2.4 times the requirement for maintaining functional independence. This was partly due to marked ventricular dilatation (left-ventricular end-diastolic volume: 273 mL), which facilitates a large peak supine exercise stroke volume (200 mL) and cardiac output (22.2 L/min). However, at the age of 78 yr, DC developed palpitations and fatigue and was found to be in atrial fibrillation requiring ablation procedures to revert his heart to sinus rhythm. Overall, this life study of a world champion marathon runner exemplifies the substantial benefits and potential side effects of many decades of intense endurance exercise.<b>NEW & NOTEWORTHY</b> This life study of a 77-yr-old former world champion marathon runner exemplifies the impact of lifelong high-volume endurance exercise on functional capacity (V̇o_2max equivalent to a 20- to 29-yr-old), partly due to extreme ventricular remodeling that facilitates a large cardiac output during exercise despite reduced maximal heart rate. Although it is possible that this extreme remodeling may contribute to developing atrial fibrillation, the net benefits of extreme exercise throughout this athlete's lifespan favor increased health span and expected longevity.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141468124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 facilitates the development of angiotensin II-induced abdominal aortic aneurysm in male mice.","authors":"Neekun Sharma, Abdelnaby Khalyfa, Dunpeng Cai, Mariana Morales-Quinones, Rogerio N Soares, Yusuke Higashi, Shiyou Chen, David Gozal, Jaume Padilla, Camila Manrique-Acevedo, Bysani Chandrasekar, Luis A Martinez-Lemus","doi":"10.1152/japplphysiol.00842.2023","DOIUrl":"10.1152/japplphysiol.00842.2023","url":null,"abstract":"<p><p>Obstructive sleep apnea (OSA), characterized by episodes of intermittent hypoxia (IH), is highly prevalent in patients with abdominal aortic aneurysm (AAA). However, whether IH serves as an independent risk factor for AAA development remains to be investigated. Here, we determined the effects of chronic (6 mo) IH on angiotensin (Ang II)-induced AAA development in C57BL/6J male mice and investigated the underlying mechanisms of IH in cultured vascular smooth muscle cells (SMCs). IH increased the susceptibility of mice to develop AAA in response to Ang II infusion by facilitating the augmentation of the abdominal aorta's diameter as assessed by transabdominal ultrasound imaging. Importantly, IH with Ang II augmented aortic elastin degradation and the expression of matrix metalloproteinases (MMPs), mainly MMP8, MMP12, and a disintegrin and metalloproteinase-17 (ADAM17) as measured by histology and immunohistochemistry. Mechanistically, IH increased the activities of MMP2, MMP8, MMP9, MMP12, and ADAM17, while reducing the expression of the MMP regulator reversion-inducing cysteine-rich protein with Kazal motifs (RECK) in cultured SMCs. Aortic samples from human AAA were associated with decreased RECK and increased expression of ADAM17 and MMPs. These data suggest that IH facilitates AAA development when additional stressors are superimposed and that this occurs in association with an increased presence of aortic MMPs and ADAM17, potentially due to IH-induced modulation of RECK expression. These findings support a plausible synergistic link between OSA and AAA and provide a better understanding of the molecular mechanisms underlying the pathogenesis of AAA.<b>NEW & NOTEWORTHY</b> IH facilitates Ang II-induced abdominal aortic diameter expansion and AAA development in C57BL/6J male mice. IH upregulates the expression of specific MMPs such as MMP8, MMP12, and ADAM17. IH directly suppresses RECK expression and increases MMPs activity in SMCs. Human AAA tissues exhibit a downregulation of RECK and an upregulation of ADAM17 and MMPs.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141310796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}