Respiratory Physiology & Neurobiology最新文献

Pathophysiological mechanisms of exertional dyspnea in people with cardiopulmonary disease: Recent advances

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-29 DOI: 10.1016/j.resp.2025.104423

Matthew D. James , Devin B. Phillips , Nicolle J. Domnik , J.Alberto Neder

{"title":"Pathophysiological mechanisms of exertional dyspnea in people with cardiopulmonary disease: Recent advances","authors":"Matthew D. James , Devin B. Phillips , Nicolle J. Domnik , J.Alberto Neder","doi":"10.1016/j.resp.2025.104423","DOIUrl":"10.1016/j.resp.2025.104423","url":null,"abstract":"<div><div>Physical activity is a leading trigger of dyspnea in chronic cardiopulmonary diseases. Recently, there has been a renewed interest in uncovering the mechanisms underlying this distressing symptom. We start by articulating a conceptual framework linking cardiorespiratory abnormalities with the central perception of undesirable respiratory sensations during exercise. We specifically emphasize that exertional dyspnea ultimately reflects an imbalance between (high) demand and (low) capacity. As such, the symptom arises in the presence of a heightened inspiratory neural drive – the will to breathe – secondary to a) increased ventilatory output relative to the instantaneous ventilatory capacity (<em>excessive</em> breathing) and/or b) its impeded translation into the act of breathing due to constraints on tidal volume expansion (<em>constrained</em> breathing). In patients with chronic obstructive pulmonary disease (COPD), asthma, cystic fibrosis, and interstitial lung disease (ILD), <em>constrained</em> breathing assumes a more dominant role as the disease progresses. <em>Excessive</em> breathing due to heightened wasted ventilation in the physiological dead space is particularly important in the initial stages of COPD, while alveolar hyperventilation has a major contributory role in hypoxemic patients with ILD. Hyperventilation is also a leading driver of dyspnea in heart failure (HF) with reduced ejection fraction (EF), while high physiological dead space is the main underlying mechanism in HF with preserved EF. Similarly, wasted ventilation in poorly perfused lung tissue dominates the scene in pulmonary vascular disease. New artificial intelligence-based approaches to expose the contribution of <em>excessive</em> and <em>constrained</em> breathing may enhance the yield of cardiopulmonary exercise testing in investigating exertional dyspnea in these patients.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"336 ","pages":"Article 104423"},"PeriodicalIF":1.9,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739229","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}

引用次数: 0

Swallowing and ventilation patterns in stable COPD patients: an observational Study.

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-28 DOI: 10.1016/j.resp.2025.104419

Virgil Rolland, Armand Bonne, Rimah Ayari, Grégoire Prum, Eric Verin

{"title":"Swallowing and ventilation patterns in stable COPD patients: an observational Study.","authors":"Virgil Rolland, Armand Bonne, Rimah Ayari, Grégoire Prum, Eric Verin","doi":"10.1016/j.resp.2025.104419","DOIUrl":"https://doi.org/10.1016/j.resp.2025.104419","url":null,"abstract":"<p><p>Our study aimed to investigate swallowing coordination by analyzing ventilatory patterns during of solids and liquids food intakes. Twenty-one patients with severe to very severe stable COPD (GOLD III and IV) underwent ventilation and swallowing recordings while performing standardized swallowing tasks. The results revealed that the expiratory-expiratory (EE) swallowing pattern was predominant, accounting for 80% of swallows, with no significant differences between solid and liquid swallows. Non-EE patterns occurred in an average of 20.68% of swallows per patient. Our results demonstrated an increased inspiratory time (IT) during liquid swallows compared to rest (1.05 ± 0.28s vs. 1.29 ± 0.22s; p < 0.0125), as well as prolonged expiratory time (ET: 2.09 ± 0.78s vs. 3.42 ± 1.16s; p < 0.001) and total respiratory cycle time (TT: 3.14 ± 1.03s vs. 4.70 ± 1.21s; p < 0.01) during both solid and liquid swallows compared to rest. These changes resulted in a decreased IT/TT ratio during swallowing. Our findings confirm that the EE swallowing pattern remains predominant in stable COPD patients, consistent with observations in healthy individuals. Additionally, the study highlights significant alterations in ventilatory patterns during swallowing. These results contribute to a better understanding of the interplay between swallowing and ventilation in COPD and its potential implications for airways protection.</p>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":" ","pages":"104419"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143753922","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}

引用次数: 0

Effects of inspiratory muscle metaboreflex on cerebral circulation at rest and during light-intensity exercise in healthy males

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-26 DOI: 10.1016/j.resp.2025.104422

Kohei Sato , Tatsuki Kamoda , Rintaro Sakamoto , Keisho Katayama , Toru Neki , Masaki Katayose , Erika Iwamoto

{"title":"Effects of inspiratory muscle metaboreflex on cerebral circulation at rest and during light-intensity exercise in healthy males","authors":"Kohei Sato , Tatsuki Kamoda , Rintaro Sakamoto , Keisho Katayama , Toru Neki , Masaki Katayose , Erika Iwamoto","doi":"10.1016/j.resp.2025.104422","DOIUrl":"10.1016/j.resp.2025.104422","url":null,"abstract":"<div><h3>Purpose</h3><div>This study aimed to clarify the effects of inspiratory muscle metaboreflex on cerebral circulation at rest and during exercise.</div></div><div><h3>Methods</h3><div>Twelve young males randomly completed two trials (rest and exercise [leg cycling at 40 % peak oxygen uptake] trials) on separate days. In each trial, the internal carotid artery (ICA), an index of cerebral circulation, was measured using Doppler ultrasound 2 min after inspiratory loading breathing (IL condition) or non-loading breathing (control condition). During ICA assessments, participants engaged in 3 min of spontaneous breathing (SB), followed by 3 min of isocapnic hyperventilation (IHV).</div></div><div><h3>Results</h3><div>ICA conductance was lower in the IL condition than in the control condition in both rest and exercise trials. Inspiratory muscle metaboreflex did not reduce ICA blood flow during SB but decreased it during IHV in both trials.</div></div><div><h3>Conclusion</h3><div>Our findings suggest that inspiratory muscle metaboreflex could decrease cerebrovascular conductance from rest to light-intensity exercise and attenuates cerebral blood flow with increased respiratory muscle work.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"336 ","pages":"Article 104422"},"PeriodicalIF":1.9,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739228","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}

引用次数: 0

Chemogenetic activation of the diaphragm after spinal cord injury in rats

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-26 DOI: 10.1016/j.resp.2025.104421

Ethan S. Benevides , Sabhya Rana , David D. Fuller

{"title":"Chemogenetic activation of the diaphragm after spinal cord injury in rats","authors":"Ethan S. Benevides , Sabhya Rana , David D. Fuller","doi":"10.1016/j.resp.2025.104421","DOIUrl":"10.1016/j.resp.2025.104421","url":null,"abstract":"<div><div>We tested the hypothesis that activation of DREADDs in the mid-cervical spinal cord could restore diaphragm activation during spontaneous breathing after cervical spinal cord injury (SCI). Adult Sprague Dawley rats (n = 7) received bilateral mid-cervical ventral horn injections of an AAV construct encoding an excitatory DREADD (AAV9-hSyn-HA-hM3D(Gq)-mCherry; titer: 2.44 × 10<sup>13</sup> vg/mL). Subsequently, diaphragm electromyogram (EMG) activity was recorded during spontaneous breathing under isoflurane anesthesia. The selective DREADD ligand JHU37160 (J60) was administered intravenously at acute (3 days), sub-acute (2 weeks), and chronic (2 months) timepoints following cervical hemilesion at spinal level C2. J60 administration resulted in robust increases in diaphragm EMG output at all timepoints, and near-complete restoration of diaphragm EMG activity from the paralyzed hemi-diaphragm in 50 % of trials. Administration of J60 to DREADD naïve, spinal intact rats (n = 8) did not produce an increase in diaphragm activity. These proof-of-concept results indicate that refinement of this technique may provide a strategy for improving diaphragm activation after cervical SCI.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"336 ","pages":"Article 104421"},"PeriodicalIF":1.9,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143743516","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}

引用次数: 0

Pulmonary stretch receptor modulation of synaptic inhibition shapes the discharge pattern of respiratory premotor neurons

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-25 DOI: 10.1016/j.resp.2025.104420

Edward J. Zuperku , Francis A. Hopp , Astrid G. Stucke

{"title":"Pulmonary stretch receptor modulation of synaptic inhibition shapes the discharge pattern of respiratory premotor neurons","authors":"Edward J. Zuperku , Francis A. Hopp , Astrid G. Stucke","doi":"10.1016/j.resp.2025.104420","DOIUrl":"10.1016/j.resp.2025.104420","url":null,"abstract":"<div><div>Many studies focus on the mechanisms of respiratory rhythm generation through neuronal interactions in the preBötzinger and Bötzinger complex area. There is limited insight into how the varied discharge patterns of propriobulbar, rhythm generating neurons are integrated to generate the slowly augmenting and decrementing discharge patterns observed in respiratory premotor neurons. Neuronal discharge patterns were obtained, <em>in vivo</em>, from inspiratory (I) and expiratory (E) premotor neurons in the ventral respiratory group of adult, anesthetized and vagotomized canines. Electrical activation of vagal afferents was used to produce pulmonary stretch receptor (PSR), step-input patterns, throughout or within either the I- or E-phase. PSR inputs decreased the discharge pattern slopes of augmenting and decrementing E-neurons and increased the slopes of augmenting and decrementing I-neurons. PSR inputs that were applied only for part of the phase acutely changed the discharge pattern to the trajectory associated with those PSR throughout-phase inputs, but the pattern returned immediately to the original trajectory after the PSR input terminated. These types of responses can be reproduced with high fidelity by a mathematical model based on reciprocal inhibition between augmenting and decrementing neurons of the same respiratory phase. Best fit is achieved when PSR inputs solely modulate the strength of the synaptic inhibition of decrementing neurons by augmenting neurons at the presynaptic level. Leaky integrator functions are not necessary to generate the gradually augmenting and decrementing patterns. This model offers a novel and different mechanistic way to conceptualize the generation and PSR control of respiratory discharge patterns.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"336 ","pages":"Article 104420"},"PeriodicalIF":1.9,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143731503","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}

引用次数: 0

Neural gating of respiratory sensations as a potential mechanism of dyspnea perception: State-of-the-art and future directions

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-24 DOI: 10.1016/j.resp.2025.104418

Valentina Jelinčić , Pei-Ying S. Chan , Paul W. Davenport , Andreas von Leupoldt

{"title":"Neural gating of respiratory sensations as a potential mechanism of dyspnea perception: State-of-the-art and future directions","authors":"Valentina Jelinčić , Pei-Ying S. Chan , Paul W. Davenport , Andreas von Leupoldt","doi":"10.1016/j.resp.2025.104418","DOIUrl":"10.1016/j.resp.2025.104418","url":null,"abstract":"<div><h3>Context</h3><div>Dyspnea – the subjective experience of breathing discomfort – is a prevalent and debilitating symptom in various chronic conditions, featuring a complex interplay of sensory, cognitive, and emotional factors contributing to its perception. In recent years, growing evidence emerged for the importance of neural processing in shaping symptom experiences such as dyspnea.</div></div><div><h3>Objective</h3><div>This frontiers review focuses on the neural gating of respiratory sensations (NGRS), as a potential neural mechanism underlying dyspnea perception. NGRS is measured by the repetition suppression of respiratory-related evoked potentials (RREP) elicited by paired inspiratory occlusions. NGRS may reflect the brain’s capacity to filter redundant respiratory input, and reduced NGRS may constitute a biomarker for aversive dyspnea experience.</div></div><div><h3>Review</h3><div>We summarize the current state-of-the-art on the relationships between NGRS and dyspnea, noting the inconsistent findings in healthy individuals along with promising evidence from clinical populations, such as chronic obstructive pulmonary disease (COPD). The inconsistent findings may be attributed to methodological limitations, including the significant variability in experimental designs and analytical choices hampering NGRS reliability, and the influence of top-down attention and expectations. In the final part of the review, we suggest future directions for the investigation of the NGRS-dyspnea relationship, including mechanistic research using advanced EEG analysis, mobile neuroimaging, and brain stimulation techniques to delineate the contributions of top-down and bottom-up mechanisms to NGRS.</div></div><div><h3>Conclusions</h3><div>By addressing the current knowledge gaps, this review forms a part of the concentrated effort to promote brain-based interventions for alleviating the distressing experience of chronic dyspnea.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"336 ","pages":"Article 104418"},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143731501","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}

引用次数: 0

Complex respiratory effects of nebulised citric acid and capsaicin as tussive agents: A comparative study in conventional and specific pathogen-free guinea pigs

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-24 DOI: 10.1016/j.resp.2025.104417

Tomas Buday , Mariana Brozmanova , Janka Jakusova , Zuzana Biringerova , Lukas Martvon , Jana Plevkova

{"title":"Complex respiratory effects of nebulised citric acid and capsaicin as tussive agents: A comparative study in conventional and specific pathogen-free guinea pigs","authors":"Tomas Buday , Mariana Brozmanova , Janka Jakusova , Zuzana Biringerova , Lukas Martvon , Jana Plevkova","doi":"10.1016/j.resp.2025.104417","DOIUrl":"10.1016/j.resp.2025.104417","url":null,"abstract":"<div><h3>Background</h3><div>Citric acid and capsaicin are commonly used in cough research due to their reproducible effects on animal models and humans. However, these extend beyond cough provocation.</div></div><div><h3>Objective</h3><div>To characterize and describe the respiratory responses to citric acid and capsaicin exposure using whole-body plethysmography in conventional (CON) and specific pathogen-free (SPF) guinea pigs.</div></div><div><h3>Methods</h3><div>Male and female guinea pigs were exposed to aerosols of saline, citric acid (0.4 M), and capsaicin (25 µM). Cough and respiratory parameters (inspiratory and expiratory time, respiratory rate, tidal volume, enhanced pause and mid-expiratory flow) were recorded.</div></div><div><h3>Results</h3><div>Both tussive agents induced upper and lower airway responses besides cough, with significant differences in respiratory parameters between CON and SPF animals. Citric acid elicited a stronger upper airway response compared to capsaicin.</div></div><div><h3>Conclusion</h3><div>Citric acid and capsaicin trigger complex respiratory responses (bronchoconstriction, braking, breathing pattern changes). These findings highlight the need to consider broader respiratory responses in translational cough research.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"334 ","pages":"Article 104417"},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704507","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}

引用次数: 0

Breath-hold diving as a tool to harness a beneficial increase in cardiac vagal tone

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-15 DOI: 10.1016/j.resp.2025.104416

Pierrick Martinez , Mathias Dutschmann , Vincent Epercieux , Géraud Gourjon , Fabrice Joulia

{"title":"Breath-hold diving as a tool to harness a beneficial increase in cardiac vagal tone","authors":"Pierrick Martinez , Mathias Dutschmann , Vincent Epercieux , Géraud Gourjon , Fabrice Joulia","doi":"10.1016/j.resp.2025.104416","DOIUrl":"10.1016/j.resp.2025.104416","url":null,"abstract":"<div><div>Here we review central mechanisms that mediate the diving bradycardia and propose that breath-hold diving (BH-D) is a powerful therapeutic tool to improve cardiac vagal tone (CVT). Physiological fluctuations in CVT are known as the respiratory heart rate variability (respirHRV) and involve two respiratory-related brainstem mechanisms. During inspiration pre-Bötzinger complex (pre-BötC) neurons inhibit cardiac vagal motor neurons to increase heart rate and subsequently cardiac vagal disinhibition and a decrease in heart rate is associated with a Kölliker-Fuse (KF) nucleus-mediated partial glottal constriction during early expiration. Both KF and pre-BötC receive direct descending cortical inputs that could mediate volitional glottal closure as critical anatomical framework to volitionally target brainstem circuits that generate CVT during BH-D. Accordingly we show that volitional and reflex glottal closure during BH-D appropriates the respirHRV core network to mediate the diving bradycardia via converging trigeminal afferents inputs from the nose and forehead. Additional sensory inputs linked to prolonged BH-D after regular training further increase CVT during the acute dive and can yield a long-term increase in CVT. Centrally, evidence of Hebbian plasticity within respirHRV/BH-D core circuit further support the notion that regular BH-D exercise can yield a permanent increase in CVT specifically via a sensitization of synapse involved in the generation of the respirHRV. Contrary to other regular physical activity, BH-D reportedly does not cause structural remodeling of the heart and therefore we suggest that regular BH-D exercise could be employed as a save and non-invasive approach to treat sympathetic hyperactivity, particularly in elderly patients with cardio-vascular predispositions.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"334 ","pages":"Article 104416"},"PeriodicalIF":1.9,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143650127","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}

引用次数: 0

Altered breathing pattern of lowlanders sleeping at high altitude: Novel insights from home sleep apnoea tests procedures

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-03-06 DOI: 10.1016/j.resp.2025.104415

Pierpaolo Prosperi , Antonella Spacone , Alberto Taverna , Riccardo Rua , Sofia Bonan , Giorgia Rapacchiale , Danilo Bondi , Camillo Di Giulio , Giuseppe Miserocchi , Vittore Verratti

{"title":"Altered breathing pattern of lowlanders sleeping at high altitude: Novel insights from home sleep apnoea tests procedures","authors":"Pierpaolo Prosperi , Antonella Spacone , Alberto Taverna , Riccardo Rua , Sofia Bonan , Giorgia Rapacchiale , Danilo Bondi , Camillo Di Giulio , Giuseppe Miserocchi , Vittore Verratti","doi":"10.1016/j.resp.2025.104415","DOIUrl":"10.1016/j.resp.2025.104415","url":null,"abstract":"<div><div>Lowlanders sojourning at high altitude often experience sleep disturbances, which are driven by blood gases alterations and manifest as stress-related patterns, including frequent awakenings, apnoeas, reduction in sleep duration and possibly with the occurrence of periodic breathing. This study demonstrated clinical evidence of sleep disturbances at high altitude by using portable device during a Himalayan expedition. The home sleep apnoea test was conducted on 10 participants taking part in the \"Lobuche Peak - Pyramid Exploration & Physiology\". The longitudinal design included five assessments, before the expedition, at pre-expedition at Kathmandu (≈1400 m), at a peak altitude of ≈ 5000 m, upon return to Kathmandu and one month after return in Italy. Total sleep time was below 7 h of duration at the highest altitude in all participants. Nocturnal SpO<sub>2</sub> dropped below daytime measurement and was greatly reduced at high altitude; conversely, heart rate increased. All participants experienced an increase in apnea-hypopnea index at high altitude, with seven out of 10 falling in moderate-to-severe grade. Periodic breathing pattern was clearly observed in two participants, of whom one developed acute mountain sickness and one did not. All the impairments were fully reversible once back at low altitude. Translationally, our findings underscore the importance of conducting home sleep apnoea tests at living altitude. Sleep-disordered breathing arises from a complex pattern that can be due to a wide range of responses, and the overall functions revealed by home sleep apnoea testing during a field expedition have the potential to increase the safety of high altitude sojourners, while advancing our knowledge of hypoxia as the red line linking respiratory and environmental physiology.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"334 ","pages":"Article 104415"},"PeriodicalIF":1.9,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586653","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}

引用次数: 0

Bulk and regional diaphragm blood flow during chemical hyperpnea in pulmonary hypertensive rats

IF 1.9 4区医学

Respiratory Physiology & Neurobiology Pub Date : 2025-02-17 DOI: 10.1016/j.resp.2025.104414

Kiana M. Schulze , Andrew G. Horn , Ramona E. Weber , K. Sue Hageman , Britton C. Scheuermann , Carl J. Ade , Bradley J. Behnke , David C. Poole , Timothy I. Musch

{"title":"Bulk and regional diaphragm blood flow during chemical hyperpnea in pulmonary hypertensive rats","authors":"Kiana M. Schulze , Andrew G. Horn , Ramona E. Weber , K. Sue Hageman , Britton C. Scheuermann , Carl J. Ade , Bradley J. Behnke , David C. Poole , Timothy I. Musch","doi":"10.1016/j.resp.2025.104414","DOIUrl":"10.1016/j.resp.2025.104414","url":null,"abstract":"<div><div>Pulmonary hypertension (PH) is a disease characterized by increased pulmonary arterial pressures, impaired gas exchange, dyspnea, and diaphragmatic dysfunction. Specifically, in PH, the diaphragm displays impaired contractility, vascular dysfunction, and blood flow redistribution toward less mechanically advantageous regions such as the ventral costal and crural diaphragm at rest and during submaximal exercise. While diaphragm blood flow is not a limitation to maximal exercise in health, whether it limits diaphragm function in PH is unknown. We hypothesized that, during chemically induced hyperpnea: 1) diaphragm blood flow will be lower in rats with PH compared with healthy controls due to vasodilatory impairments in the diaphragm vasculature, and 2) in PH, blood flow will be redistributed toward less mechanically advantageous regions of the diaphragm. Female Sprague-Dawley rats were randomized into healthy (n = 12) or monocrotaline-induced PH (n = 12) groups. Fluorescent microspheres were used to determine bulk and regional diaphragm blood flow at rest and during hypoxic-hypercapnic gas inhalation (10 % O<sub>2</sub>-8 % CO<sub>2</sub>). During chemically induced hyperpnea, diaphragm blood flow was higher in PH compared with healthy controls (483 ± 102 vs. 298 ± 119 ml/min/100 g; P < 0.001), and the ventral costal and crural regions of the diaphragm supported greater perfusion in PH. These results are consistent with previous findings at rest and during submaximal exercise in PH, which may help explain diaphragmatic weakness and dyspnea across a range of ventilatory demands in PH.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104414"},"PeriodicalIF":1.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143458975","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}

引用次数: 0