Experimental Physiology最新文献

{"title":"Repetition-dependent acutecardiopulmonary responses during intensity-matched squats in males.","authors":"Johannes Lässing, Sonja Hummelmann, Maxi Kramer, Ulrich Laufs, Sven Fikenzer, Roberto Falz","doi":"10.1113/EP092363","DOIUrl":"https://doi.org/10.1113/EP092363","url":null,"abstract":"<p><p>The 'strength-endurance continuum' is a key concept in strength training (ST). Although cardiopulmonary responses have seldom been reported in conjunction with ST, this repeated-measurement study examined acute blood pressure and haemodynamic responses continuously depending on the number of repetitions but without changing the intensity. Fifteen healthy male participants (21.6 (2.0) years; mean (SD)) performed an incremental exercise test and a 3-repetition maximum test (3-RM) on a Smith machine. They were then randomly assigned to three ST sessions involving 10, 20 and 30 repetitions at 50% of their 3-RM. Blood pressure (vascular unloading technique) and cardiopulmonary responses (spirometry and impedance cardiography) were continuously monitored. Heart rate (121 (10) vs. 139 (22) vs. 153 (13) bpm, P = 0.001, respectively), cardiac output (10.4 (1.9) vs. 13.6 (3.8) vs. 14.6 (3.1) L/min, P = 0.001, respectively) and diastolic blood pressure (113 (8) vs. 116 (21) vs. 135 (22) mmHg, P = 0.001, respectively) increased in the training sessions with higher repetitions. Stroke volume, systolic blood pressure and end-diastolic volume indicated no change in peak values between training sessions. Total peripheral resistance (13.6 (2.8) vs. 11.3 (3.6) vs. 11.2 (3.1) mmHg min/L, P = 0.002, respectively) was significantly lower with 20 and 30 repetitions, while oxygen uptake ( <math> <semantics> <msub><mover><mi>V</mi> <mo>̇</mo></mover> <msub><mi>O</mi> <mn>2</mn></msub> </msub> <annotation>${dot V_{{{mathrm{O}}_{mathrm{2}}}}}$</annotation></semantics> </math> : 15.5 (1.9) vs. 20.5 (4.1) vs. 20.6 (4.4) mL/min/kg, P = 0.001, respectively) was significantly higher. ST of moderate intensity with an exhausting number (>20) of repetitions induces strong haemodynamic responses, especially high cardiac afterload and a compensatory heart rate acceleration, which may also create a strong stimulus for cardiopulmonary adaptation.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476455","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":"Decoding the space integrome: Personalized countermeasures for a mission to Mars.","authors":"Damian M Bailey","doi":"10.1113/EP092629","DOIUrl":"https://doi.org/10.1113/EP092629","url":null,"abstract":"","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466610","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":"Intact microdissection of stellate ganglia in a Parkinson's disease model reveals aggregation of mutant human α-synuclein in their cell bodies.","authors":"Bonn Lee, Shiraz Ahmad, Charlotte E Edling, Fiona E N LeBeau, Kamalan Jeevaratnam","doi":"10.1113/EP092261","DOIUrl":"https://doi.org/10.1113/EP092261","url":null,"abstract":"<p><p>Cardiac dysautonomia plays an important role in understanding Parkinson's disease (PD), with recent studies highlighting the presence of α-synuclein in cardiac tissue. We hypothesise that sympathetic dysregulation observed in PD may involve pathological changes caused by α-synuclein in stellate ganglia (SG). This study aimed to investigate α-synucleinopathy in SG of the genetic PD murine animal model. Mice overexpressing Ala30Pro (A30P) mutant α-synuclein were used. We here demonstrate a technique for meticulously dissecting SG. The collected SG from the transgenic mice were immunolabelled with neuronal markers, A30P human mutant α-synuclein and anti-α-synuclein aggregates. A30P mutant α-synuclein protein was expressed in the sympathetic neuronal (tyrosine hydroxylase (TH)-positive) cell bodies. Approximately 27% of the TH-positive cell bodies expressed the A30P mutant α-synuclein protein. The mutant protein was densely localised at the cardiopulmonary pole of the SG. Additionally, we observed that the A30P mutant protein formed fibril aggregation in the SG. Our findings suggest that α-synucleinopathy in the PD animal model can affect the sympathetic autonomic nervous system, providing insight for further research into targeting α-synuclein pathology in the SG as a potential link between cardiac dysautonomia and PD.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476388","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 state of mechanistic research in the evidence-based medicine era: A sandwalk between triangulation and hierarchies.","authors":"Ronan M G Berg, Cody G Durrer, Jan Kyrre Berg Olsen Friis, Mathias Ried-Larsen","doi":"10.1113/EP092157","DOIUrl":"https://doi.org/10.1113/EP092157","url":null,"abstract":"","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143467112","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":"Role of prespecified analysis plans in physiological research: Encouraged or mandatory?","authors":"Robin Christensen, Tobias Haugegaard, Janus C Jakobsen","doi":"10.1113/EP092034","DOIUrl":"https://doi.org/10.1113/EP092034","url":null,"abstract":"","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143467111","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":"Breath-by-breath measurement of alveolar gas exchange must preserve mass balance and conform to a physiological definition of a breath.","authors":"Michele Girardi, Carlo Capelli, Carrie Ferguson, Susan A Ward, Harry B Rossiter","doi":"10.1113/EP092221","DOIUrl":"https://doi.org/10.1113/EP092221","url":null,"abstract":"<p><p>Tidal breathing in awake humans is variable. This variability causes changes in lung gas stores that affect gas exchange measurements. To overcome this, several algorithms provide solutions for breath-by-breath alveolar gas exchange measurement; however, there is no consensus on a physiologically robust method suitable for widespread application. A recent approach, the 'independent-breath' (IND) algorithm, avoids the complexity of measuring breath-by-breath changes in lung volume by redefining what is meant by a 'breath'. Specifically, it defines a single breathing cycle as the time between equal values of the <math> <semantics><msub><mi>F</mi> <msub><mi>O</mi> <mn>2</mn></msub> </msub> <annotation>${F_{{{mathrm{O}}_2}}}$</annotation></semantics> </math> / <math> <semantics><msub><mi>F</mi> <msub><mi>N</mi> <mn>2</mn></msub> </msub> <annotation>${F_{{{mathrm{N}}_2}}}$</annotation></semantics> </math> (or <math> <semantics><msub><mi>F</mi> <mrow><mi>C</mi> <msub><mi>O</mi> <mn>2</mn></msub> </mrow> </msub> <annotation>${F_{{mathrm{C}}{{mathrm{O}}_2}}}$</annotation></semantics> </math> / <math> <semantics><msub><mi>F</mi> <msub><mi>N</mi> <mn>2</mn></msub> </msub> <annotation>${F_{{{mathrm{N}}_2}}}$</annotation></semantics> </math> ) ratio, that is, the ratio of fractional concentrations of lung-expired O₂ (or CO₂) and nitrogen (N₂). These developments imply that the end of one breath is not, by necessity, aligned with the start of the next. Here we demonstrate how the use of the IND algorithm fails to conserve breath-by-breath mass balance of O₂ and CO₂ exchanged between the atmosphere and tissues (and vice versa). We propose a new term, within the IND algorithm, designed to overcome this limitation. We also present the far-reaching implications of using algorithms based on alternative definitions of the breathing cycle, including challenges in measuring and interpreting the respiratory exchange ratio, pulmonary gas exchange efficiency, dead space fraction of the breath, control of breathing, and a broad spectrum of clinically relevant cardiopulmonary exercise testing variables. Therefore, we do not support the widespread adoption of currently available alternative definitions of the breathing cycle as a legitimate solution for breath-by-breath alveolar gas exchange measurement in research or clinical settings.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476385","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":"A method for dyadic cardiac rhythmicity analysis: Preliminary evidence on bilateral interactions in fetal-maternal cardiac dynamics.","authors":"Diego Candia-Rivera, Mario Chavez","doi":"10.1113/EP092532","DOIUrl":"https://doi.org/10.1113/EP092532","url":null,"abstract":"<p><p>Cardiac activity responds dynamically to metabolic demands and neural regulation. However, little is known about this process during pregnancy. Reports show occasional fetal-maternal heart rate couplings, but it has remained unclear whether these couplings extend to more complex oscillatory patterns of the heart rhythm. We developed a framework of time-varying measures of heart rate and rhythm, to test the presence of co-varying patterns in concurrent maternal and fetal measures (late pregnancy dataset, n = 10, and labour dataset, n = 12). These measures were derived from first and second-order Poincaré plots, with the aim to describe changes in short- and long-term rhythmicity, but also the dynamic shifts in acceleration and deceleration of heart rate. We found episodes of maternal-fetal co-varying patterns of cardiac rhythm in all the measures explored, in both datasets (at least 90% of the dataset presented a significant maternal-fetal correlation in each measure, with P < 0.001), with dynamic delays suggesting bilateral interactions at different time scales. We also found that these couplings intensify during labour (test between late pregnancy vs. labour datasets, P < 0.0015 in all second-order Poincaré plot-derived measures). While most literature suggests that the fetal heart responds to maternal breathing patterns or contractions, we propose the possibility that the fetal heart may also have a signalling function in the context of co-regulatory mechanisms and maternal inter-organ interactions. Understanding these complex visceral oscillations in utero may enhance the assessment of a healthy fetal development.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476384","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":"Impact of exercise training on tumour-infiltrating T cells in human prostate cancer: A secondary analysis of a randomized controlled trial (PRO-TEST).","authors":"Simon Nørskov Thomsen, Emil Wriedt, Marianne Gardar Stærk, Sissal Sigmundsdottir Djurhuus, Birgitte Grønkær Toft, Sabrina Wielsøe, Andreas Røder, Thomas Hasselager, Peter Busch Østergren, Henrik Jakobsen, Klaus Brasso, Jesper Frank Christensen, Louise Lang Lehrskov, Casper Simonsen","doi":"10.1113/EP092374","DOIUrl":"https://doi.org/10.1113/EP092374","url":null,"abstract":"<p><p>Exercise training reduces tumour growth by increasing tumour-infiltrating T-cell density in preclinical models. However, it remains unknown whether exercise training can modify intratumoural T cells in humans.The aim of this study was to compare the effects of an exercise training intervention versus control on human prostate intratumoural T-cell density.This study is a secondary analysis of a randomized controlled trial. We randomly allocated men (age > 18 years) with treatment-naive localized prostate cancer scheduled for radical prostatectomy 2:1 to exercise training intervention or control. The exercise intervention consisted of supervised, high-intensity interval bicycling four times per week from the time of randomization until prostatectomy. Intratumoural CD3⁺ and CD8⁺ T-cell densities in diagnostic biopsies and postsurgical prostatectomy specimens were quantified using immunohistochemistry. Between-group differences in changes from baseline to follow-up were estimated using constrained baseline linear mixed-effect models.A total of 30 participants were included (exercise intervention, n = 20; control, n = 10). We found no between-group differences in changes in CD3⁺ T cells [mean difference (95% confidence interval): -17 (-185; 150) cells/mm²] or CD8⁺ T cells [mean difference (95% confidence interval): -16 (-206; 172) cells/mm²]. Additionally, we found no statistically significant correlations between changes in T-cell density and the number of exercise training sessions attended or changes in maximal oxygen consumption.In this secondary analysis of a randomized controlled trial, we found no impact of the exercise regimen on tumour-infiltrating CD3⁺ and CD8⁺ T-cell density in human prostate cancer.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143457358","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":"From bedside to seaside: An academic's attempt at freediving.","authors":"Anthony R Bain","doi":"10.1113/EP092405","DOIUrl":"https://doi.org/10.1113/EP092405","url":null,"abstract":"","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143448677","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":"Heart rate response to transient hypoxia in patients with heart failure and Cheyne–Stokes respiration","authors":"Gian Domenico Pinna,&nbsp;Elena Robbi,&nbsp;Maria Teresa La Rovere,&nbsp;Roberto Maestri","doi":"10.1113/EP092304","DOIUrl":"10.1113/EP092304","url":null,"abstract":"<p>Cheyne–Stokes respiration (CSR), a rhythmic rise and fall in ventilation often experienced by patients with heart failure during sleep, is typically accompanied by an oscillation in heart rate (HR) at the same frequency. The mechanisms responsible for this oscillation are still debated. In this study, we used the experimental model of the transient hypoxia test (i.e., a laboratory test that mimics the transient nature of the cyclic desaturations that occur during hyperpnoeic phases of CSR) to assess accurately the temporal relationship between the HR response to transient hypoxia and the tidal volume response in six heart failure patients. The same relationship was assessed during CSR using polysomnographic signals. We hypothesized that this relationship would provide important insights into the key mechanisms contributing to the HR response. During transient hypoxia, HR started to increase around the onset of tidal volume increase but continued to increase after the peak of the latter had been reached. The time delay between the two peaks (HR vs. tidal volume) was 7.9 ± 4.8 s. The same delay during hyperpnoeic phases of CSR was 1.0 ± 0.9 s. In addition, the increases in lung volume were much greater than those found in the laboratory tests. Based on the known dynamics of vagal and sympathetic control of HR, we speculate that the HR response to transient hypoxia might be attributable predominantly to the sympathetically mediated tachycardic effect of the increased central inspiratory drive, whereas the fast, vagally mediated pulmonary inflation reflex might be the predominant mechanism during CSR.</p>","PeriodicalId":12092,"journal":{"name":"Experimental Physiology","volume":"110 4","pages":"532-542"},"PeriodicalIF":2.6,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1113/EP092304","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143440267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}