Pub Date : 2025-02-01DOI: 10.1016/j.resp.2024.104384
Tomas Buday , Mariana Brozmanova , Janka Jakusova , Abdullah Al Owesie , Laura Sophie Ertl , Daniela Mokra , Juliana Hanusrichterova , Tatiana Burjanivova , Zuzana Biringerova , Jana Plevkova
Objective
This study investigates the breathing patterns and immune status of guinea pigs raised under specific pathogen-free (SPF) conditions compared to conventionally bred (CON).
Methods
Breathing pattern parameters were assessed using whole-body plethysmography (WBP) during quiet breathing and saline nebulisation. Blood and bronchoalveolar lavage fluid (BALF) were analysed for white blood cell, neutrophil and eosinophil counts, and cytokine levels (TNF-α, IL-1β, IL-4).
Results
SPF guinea pigs exhibited higher tidal volume, expired volume, minute volume, and airflow parameters than CON guinea pigs. The immune analysis revealed lower white blood cell counts and IL-4 levels in SPF guinea pigs. These findings indicate that SPF guinea pigs have different respiratory and immune responses than CON guinea pigs.
Conclusion
The study highlights that the maturation processes affecting breathing pattern parameters in SPF guinea pigs differ significantly from those in CON guinea pigs. This suggests potential limitations of SPF animals in respiratory physiology research due to their different immune and respiratory responses.
目的：本研究调查了在特定无病原体（SPF）条件下饲养的豚鼠与传统饲养（CON）的豚鼠的呼吸模式和免疫状况：本研究调查了在特定无病原体（SPF）条件下饲养的豚鼠与传统饲养（CON）的豚鼠的呼吸模式和免疫状态：方法：在安静呼吸和生理盐水雾化时使用全身胸透（WBP）评估呼吸模式参数。分析血液和支气管肺泡灌洗液（BALF）中的白细胞、中性粒细胞和嗜酸性粒细胞计数以及细胞因子水平（TNF-α、IL-1β、IL-4）：结果：SPF豚鼠的潮气量、呼气量、分钟量和气流参数均高于CON豚鼠。免疫分析显示，SPF豚鼠的白细胞计数和IL-4水平较低。这些结果表明，SPF 豚鼠的呼吸和免疫反应与 CON 豚鼠不同：本研究强调，影响 SPF 豚鼠呼吸模式参数的成熟过程与 CON 豚鼠的成熟过程存在显著差异。这表明，由于豚鼠的免疫和呼吸反应不同，SPF 动物在呼吸生理学研究中可能存在局限性。
{"title":"Impact of microbial diversity on inflammatory cytokines and respiratory pattern measured in whole-body plethysmography in guinea pig models","authors":"Tomas Buday , Mariana Brozmanova , Janka Jakusova , Abdullah Al Owesie , Laura Sophie Ertl , Daniela Mokra , Juliana Hanusrichterova , Tatiana Burjanivova , Zuzana Biringerova , Jana Plevkova","doi":"10.1016/j.resp.2024.104384","DOIUrl":"10.1016/j.resp.2024.104384","url":null,"abstract":"<div><h3>Objective</h3><div>This study investigates the breathing patterns and immune status of guinea pigs raised under specific pathogen-free (SPF) conditions compared to conventionally bred (CON).</div></div><div><h3>Methods</h3><div>Breathing pattern parameters were assessed using whole-body plethysmography (WBP) during quiet breathing and saline nebulisation. Blood and bronchoalveolar lavage fluid (BALF) were analysed for white blood cell, neutrophil and eosinophil counts, and cytokine levels (TNF-α, IL-1β, IL-4).</div></div><div><h3>Results</h3><div>SPF guinea pigs exhibited higher tidal volume, expired volume, minute volume, and airflow parameters than CON guinea pigs. The immune analysis revealed lower white blood cell counts and IL-4 levels in SPF guinea pigs. These findings indicate that SPF guinea pigs have different respiratory and immune responses than CON guinea pigs.</div></div><div><h3>Conclusion</h3><div>The study highlights that the maturation processes affecting breathing pattern parameters in SPF guinea pigs differ significantly from those in CON guinea pigs. This suggests potential limitations of SPF animals in respiratory physiology research due to their different immune and respiratory responses.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"332 ","pages":"Article 104384"},"PeriodicalIF":1.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142795085","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}
High spinal cord injuries (SCIs) often result in persistent diaphragm paralysis and respiratory dysfunction. Chronic neuroinflammation within the damaged spinal cord after injury plays a prominent role in limiting functional recovery by impeding neuroplasticity. In this study, we aimed to reduce glucose metabolism that supports neuroinflammatory processes in an acute preclinical model of C2 spinal cord lateral hemisection in rats. We administered 2-deoxy-D-glucose (2-DG; 200 mg/kg/day s.c., for 7 days) and evaluated the effect on respiratory function and chondroitin sulfate proteoglycans (CSPGs) production around spinal phrenic motoneurons. Contrary to our initial hypothesis, our 2-DG treatment did not have any effect on diaphragm activity and CSPGs production in injured rats, although slight increases in tidal volume were observed. Unexpectedly, it led to deleterious effects in uninjured (sham) animals, characterized by increased ventilation and CSPGs production. Ultimately, our results seem to indicate that this 2-DG treatment paradigm may create a neuroinflammatory state in healthy animals, without affecting the already established spinal inflammation in injured rats.
{"title":"Glycolytic metabolism modulation on spinal neuroinflammation and vital functions following cervical spinal cord injury","authors":"Pauline Michel-Flutot , Arnaud Mansart , Stéphane Vinit","doi":"10.1016/j.resp.2024.104383","DOIUrl":"10.1016/j.resp.2024.104383","url":null,"abstract":"<div><div>High spinal cord injuries (SCIs) often result in persistent diaphragm paralysis and respiratory dysfunction. Chronic neuroinflammation within the damaged spinal cord after injury plays a prominent role in limiting functional recovery by impeding neuroplasticity. In this study, we aimed to reduce glucose metabolism that supports neuroinflammatory processes in an acute preclinical model of C2 spinal cord lateral hemisection in rats. We administered 2-deoxy-D-glucose (2-DG; 200 mg/kg/day s.c., for 7 days) and evaluated the effect on respiratory function and chondroitin sulfate proteoglycans (CSPGs) production around spinal phrenic motoneurons. Contrary to our initial hypothesis, our 2-DG treatment did not have any effect on diaphragm activity and CSPGs production in injured rats, although slight increases in tidal volume were observed. Unexpectedly, it led to deleterious effects in uninjured (sham) animals, characterized by increased ventilation and CSPGs production. Ultimately, our results seem to indicate that this 2-DG treatment paradigm may create a neuroinflammatory state in healthy animals, without affecting the already established spinal inflammation in injured rats.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"332 ","pages":"Article 104383"},"PeriodicalIF":1.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142791594","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}
Pub Date : 2025-02-01DOI: 10.1016/j.resp.2024.104382
Elder Nascimento Pereira , Fernando Zanela da Silva Arêas , Swyanne Rosenete Scantelbury Neves Tavares , Beatriz Campelo Monteiro , Ellem Nara Tananta Dantas , Renato Campos Freire Jr , Cassia da Luz Goulart , Fernando de Almeida Val , Jorge Henriques , Guilherme Peixoto Tinoco Arêas
Introduction
Transcranial direct current stimulation (tDCS) is a non-invasive technique with therapeutic potential, especially in respiratory muscle training (RMT) in pathological conditions such as chronic obstructive pulmonary disease and heart failure.
Objective
To evaluate the effect of bilateral cathodic tDCS on respiratory muscle strength and endurance in healthy young and elderly women.
Methods
An experimental, randomized study with 80 participants divided into young and old women, subdivided into intervention and sham control groups. The participants were evaluated by spirometry and dynamic muscle strength tests before and after the one session intervention. tDCS was applied with cathode electrodes positioned bilaterally in the motor area.
Results
The elderly women in the intervention group showed significant improvement in dynamic inspiratory muscle strength (S-Index) and dominant hand strength, with moderate to large effect sizes. The young women showed a significant increase only in the strength of the dominant hand, with no improvement in inspiratory muscle strength. There were no significant differences in ventilatory parameters, including Maximal Ventilatory Capacity, in any of the age groups.
Conclusion
Bilateral cathodic tDCS was effective in increasing dynamic inspiratory muscle strength and dominant hand strength in elderly women, with more pronounced effects compared to young women. The technique did not produce significant changes in maximal ventilatory capacity in any of the age groups, suggesting that the response to tDCS may vary with age, being more beneficial in elderly women.
{"title":"The acute effect of bilateral cathodic transcranial direct current stimulation on respiratory muscle strength and endurance","authors":"Elder Nascimento Pereira , Fernando Zanela da Silva Arêas , Swyanne Rosenete Scantelbury Neves Tavares , Beatriz Campelo Monteiro , Ellem Nara Tananta Dantas , Renato Campos Freire Jr , Cassia da Luz Goulart , Fernando de Almeida Val , Jorge Henriques , Guilherme Peixoto Tinoco Arêas","doi":"10.1016/j.resp.2024.104382","DOIUrl":"10.1016/j.resp.2024.104382","url":null,"abstract":"<div><h3>Introduction</h3><div>Transcranial direct current stimulation (tDCS) is a non-invasive technique with therapeutic potential, especially in respiratory muscle training (RMT) in pathological conditions such as chronic obstructive pulmonary disease and heart failure.</div></div><div><h3>Objective</h3><div>To evaluate the effect of bilateral cathodic tDCS on respiratory muscle strength and endurance in healthy young and elderly women.</div></div><div><h3>Methods</h3><div>An experimental, randomized study with 80 participants divided into young and old women, subdivided into intervention and sham control groups. The participants were evaluated by spirometry and dynamic muscle strength tests before and after the one session intervention. tDCS was applied with cathode electrodes positioned bilaterally in the motor area.</div></div><div><h3>Results</h3><div>The elderly women in the intervention group showed significant improvement in dynamic inspiratory muscle strength (S-Index) and dominant hand strength, with moderate to large effect sizes. The young women showed a significant increase only in the strength of the dominant hand, with no improvement in inspiratory muscle strength. There were no significant differences in ventilatory parameters, including Maximal Ventilatory Capacity, in any of the age groups.</div></div><div><h3>Conclusion</h3><div>Bilateral cathodic tDCS was effective in increasing dynamic inspiratory muscle strength and dominant hand strength in elderly women, with more pronounced effects compared to young women. The technique did not produce significant changes in maximal ventilatory capacity in any of the age groups, suggesting that the response to tDCS may vary with age, being more beneficial in elderly women.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"332 ","pages":"Article 104382"},"PeriodicalIF":1.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847539","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}
Pub Date : 2025-01-25DOI: 10.1016/j.resp.2025.104398
Viktor Elmberg , Gufran Ali , David Gustafsson , Dennis Jensen , Magnus Ekström
Background/aim
Exertional breathlessness is a dominating symptom in cardiorespiratory disease, limiting exercise capacity. Multidimensional measurement has been proposed to capture breathlessness, but it is unknown whether it is useful to differentiate people with abnormal vs normal exertional breathlessness intensity.
Methods
This was a secondary analysis of a randomized controlled trial of outpatients aged ≥ 18 years performing a symptom-limited cycle incremental exercise test (IET). Breathlessness sensations at end of IET were identified using the multidimensional dyspnea profile (MDP) 30-min post-exercise and compared between people with abnormally high breathlessness (Borg 0–10 rating > upper limit of normal [ULN]) and people within normal ranges (≤ ULN) in relation to the percentage of predicted peak power output defined by normative reference equations.
Results
Of 92 participants, 20 (22 %) had abnormally high breathlessness. Compared with those with normal breathlessness (n = 72 [78 %]), the abnormal group reported higher symptom intensity at peak exercise (7.9 ± 1.7 vs 6.3 ± 1.4 Borg units; p < 0.001) and had lower peak power output 129 ± 52 W vs 167 ± 55 W; p < 0.001). Differences between those with normal, and abnormal exertional breathlessness regarding MDP ratings were not statistically significant (all p > 0.05): overall unpleasantness, 4.1 ± 2.3 vs 4.7 ± 1.6; immediate perception, 10.9 ± 2.8 vs 11.5 ± 1.8; and emotional response, 4.1 ± 7.6 vs 3.2 ± 7.5. MDP ratings had no relation to peak power output.
Conclusion
Breathlessness dimensions are similar at the peak of a standardized IET and cannot differentiate between people with normal and abnormally high exertional breathlessness.
{"title":"Breathlessness dimensions should be evaluated in relation to the level of exertion: A clinical study","authors":"Viktor Elmberg , Gufran Ali , David Gustafsson , Dennis Jensen , Magnus Ekström","doi":"10.1016/j.resp.2025.104398","DOIUrl":"10.1016/j.resp.2025.104398","url":null,"abstract":"<div><h3>Background/aim</h3><div>Exertional breathlessness is a dominating symptom in cardiorespiratory disease, limiting exercise capacity. Multidimensional measurement has been proposed to capture breathlessness, but it is unknown whether it is useful to differentiate people with abnormal vs normal exertional breathlessness intensity.</div></div><div><h3>Methods</h3><div>This was a secondary analysis of a randomized controlled trial of outpatients aged ≥ 18 years performing a symptom-limited cycle incremental exercise test (IET). Breathlessness sensations at end of IET were identified using the multidimensional dyspnea profile (MDP) 30-min post-exercise and compared between people with abnormally high breathlessness (Borg 0–10 rating > upper limit of normal [ULN]) and people within normal ranges (≤ ULN) in relation to the percentage of predicted peak power output defined by normative reference equations.</div></div><div><h3>Results</h3><div>Of 92 participants, 20 (22 %) had abnormally high breathlessness. Compared with those with normal breathlessness (n = 72 [78 %]), the abnormal group reported higher symptom intensity at peak exercise (7.9 ± 1.7 vs 6.3 ± 1.4 Borg units; p < 0.001) and had lower peak power output 129 ± 52 W vs 167 ± 55 W; p < 0.001). Differences between those with normal, and abnormal exertional breathlessness regarding MDP ratings were not statistically significant (all p > 0.05): overall unpleasantness, 4.1 ± 2.3 vs 4.7 ± 1.6; immediate perception, 10.9 ± 2.8 vs 11.5 ± 1.8; and emotional response, 4.1 ± 7.6 vs 3.2 ± 7.5. MDP ratings had no relation to peak power output.</div></div><div><h3>Conclusion</h3><div>Breathlessness dimensions are similar at the peak of a standardized IET and cannot differentiate between people with normal and abnormally high exertional breathlessness.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"333 ","pages":"Article 104398"},"PeriodicalIF":1.9,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143053392","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}
Pub Date : 2025-01-16DOI: 10.1016/j.resp.2025.104397
Xinlei Huang , Goutam Saha , Akshoy Ranjan Paul , Adele Tahan , Suvash C. Saha
Central and Obstructive Sleep Apnea (CSA and OSA), Chronic Obstructive Pulmonary Disease (COPD), and Obesity Hypoventilation Syndrome (OHS) disrupt breathing patterns, posing significant health risks and reducing the quality of life. Bilevel Positive Airway Pressure (BiPAP) therapy offers adjustable inhalation and exhalation pressures, potentially enhancing treatment adaptability for the above diseases. This is the first-ever study that employs Computational Fluid Dynamics (CFD) to examine the biomechanical impacts of BiPAP under four settings: Inspiratory Positive Airway Pressure (IPAP)/Expiratory Positive Airway Pressure (EPAP) of 12/8, 16/6, and 18/8 cmH2O, compared to a without-BiPAP scenario of zero-gauge pressure. Utilizing a computed-tomography-based respiratory tract model from the nasal cavity extending to the 13th generation, we analyzed parameters such as static pressure, shear stress, and airway wall normal force across different airway regions. Our results indicate that BiPAP, particularly at higher IPAP settings, effectively increases static pressure, thereby improving airway patency and potentially reducing the risk of airway collapse in both CSA and OSA. Lower EPAP, on the other hand, helps reduce the work of breathing during exhalation, which is particularly useful for patients who have difficulty exhaling against higher pressures or need to exhale CO2 more effectively. This comparative analysis confirms that BiPAP not only maintains open airways but does so with an adjustable approach that can be used for the specific needs of patients with various respiratory dysfunctions, thereby offering a versatile and effective treatment option.
{"title":"A computational fluid dynamics analysis of BiPAP pressure settings on airway biomechanics using a CT-based respiratory tract model","authors":"Xinlei Huang , Goutam Saha , Akshoy Ranjan Paul , Adele Tahan , Suvash C. Saha","doi":"10.1016/j.resp.2025.104397","DOIUrl":"10.1016/j.resp.2025.104397","url":null,"abstract":"<div><div>Central and Obstructive Sleep Apnea (CSA and OSA), Chronic Obstructive Pulmonary Disease (COPD), and Obesity Hypoventilation Syndrome (OHS) disrupt breathing patterns, posing significant health risks and reducing the quality of life. Bilevel Positive Airway Pressure (BiPAP) therapy offers adjustable inhalation and exhalation pressures, potentially enhancing treatment adaptability for the above diseases. This is the first-ever study that employs Computational Fluid Dynamics (CFD) to examine the biomechanical impacts of BiPAP under four settings: Inspiratory Positive Airway Pressure (IPAP)/Expiratory Positive Airway Pressure (EPAP) of 12/8, 16/6, and 18/8 cmH<sub>2</sub>O, compared to a without-BiPAP scenario of zero-gauge pressure. Utilizing a computed-tomography-based respiratory tract model from the nasal cavity extending to the 13th generation, we analyzed parameters such as static pressure, shear stress, and airway wall normal force across different airway regions. Our results indicate that BiPAP, particularly at higher IPAP settings, effectively increases static pressure, thereby improving airway patency and potentially reducing the risk of airway collapse in both CSA and OSA. Lower EPAP, on the other hand, helps reduce the work of breathing during exhalation, which is particularly useful for patients who have difficulty exhaling against higher pressures or need to exhale CO<sub>2</sub> more effectively. This comparative analysis confirms that BiPAP not only maintains open airways but does so with an adjustable approach that can be used for the specific needs of patients with various respiratory dysfunctions, thereby offering a versatile and effective treatment option.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"333 ","pages":"Article 104397"},"PeriodicalIF":1.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143010685","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}
Pub Date : 2025-01-13DOI: 10.1016/j.resp.2025.104396
Yumiao Ren , Lin Xie , Xiaoni Wang , Jianbao Zhang
The central neural mechanism plays an important role in cardiopulmonary coupling. How the brain stem affects the cardiopulmonary coupling is relatively clear, but there are few studies on the cerebral cortex activity of cardiopulmonary coupling. We aim to study the response of the cerebral cortex for cardiopulmonary phase synchronization enhancement. The method of brain network was used and Pearson correlation analysis performed on the global attributes and phase synchronization time (CRPST) in the spontaneous, 2/2 and 4/4 breathing modes. Furthermore, calculated the phase lag index (PLI) among 21 lead EEG signals, and then analyzed the correlation between PLI and the parameters of cardiovascular and respiratory systems. Our results show that the global brain network characteristic parameters are significantly different in the three breath modes in the α (8–14 Hz) band. The global efficiency and feature path length are significantly positively correlated with the phase synchronization and PLI indexes are widely related to CRPST and respiratory depth in the spontaneous breathing mode, while the brain network parameters and PLI indexes are not correlated with CRPST and PLI mainly positively correlated with respiratory rate in the controlled breathing modes. The differences of brain networks in the three modes are mainly caused by the physiological factors of cardiopulmonary coupling. These show that enhanced cardiopulmonary phase synchronization with controlled breathing based on heartbeat has a significant effect on the cardiopulmonary system and maybe provide some ideas for regulating cardiopulmonary function in the future.
{"title":"Characteristics of brain network after cardiopulmonary phase synchronization enhancement","authors":"Yumiao Ren , Lin Xie , Xiaoni Wang , Jianbao Zhang","doi":"10.1016/j.resp.2025.104396","DOIUrl":"10.1016/j.resp.2025.104396","url":null,"abstract":"<div><div>The central neural mechanism plays an important role in cardiopulmonary coupling. How the brain stem affects the cardiopulmonary coupling is relatively clear, but there are few studies on the cerebral cortex activity of cardiopulmonary coupling. We aim to study the response of the cerebral cortex for cardiopulmonary phase synchronization enhancement. The method of brain network was used and Pearson correlation analysis performed on the global attributes and phase synchronization time (CRPST) in the spontaneous, 2/2 and 4/4 breathing modes. Furthermore, calculated the phase lag index (PLI) among 21 lead EEG signals, and then analyzed the correlation between PLI and the parameters of cardiovascular and respiratory systems. Our results show that the global brain network characteristic parameters are significantly different in the three breath modes in the α (8–14 Hz) band. The global efficiency and feature path length are significantly positively correlated with the phase synchronization and PLI indexes are widely related to CRPST and respiratory depth in the spontaneous breathing mode, while the brain network parameters and PLI indexes are not correlated with CRPST and PLI mainly positively correlated with respiratory rate in the controlled breathing modes. The differences of brain networks in the three modes are mainly caused by the physiological factors of cardiopulmonary coupling. These show that enhanced cardiopulmonary phase synchronization with controlled breathing based on heartbeat has a significant effect on the cardiopulmonary system and maybe provide some ideas for regulating cardiopulmonary function in the future.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"333 ","pages":"Article 104396"},"PeriodicalIF":1.9,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143010688","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}
Well-trained individuals, compared to less well-trained individuals, exhibit a lower minute ventilation (V̇E) and higher end-tidal partial pressure of CO2 (PETCO2) at a given work rate. This study investigated whether such breathing adaptations seen in well-trained individuals also applied to elite long-distance runners. Forty-one long-distance runners were categorized into high (Long-High, consisting of Tokyo-Hakone College Ekiden [relay marathon] runners and Olympic athletes, n = 23), or low performance-level group (Long-Low, n = 18) according to their race times. Ten middle-distance runners (Middle) also participated in a comparison group. All subjects performed an incremental exercise test on a motorized treadmill until exhaustion. Maximum V̇O2 and velocity were greater for the Long groups than the Middle group, however these measures were not distinguishable between the Long-High and the Long-Low groups. By contrast, V̇E and PETCO2 were able to identify the Long-High group. Submaximal V̇E were lowest, whilst PETCO2 especially at high running velocities were highest for the Long-High group. This study confirms that breathing patterns with lower V̇E and higher PETCO2 are relevant adaptation markers for assessing endurance race performance in elite long-distance runners.
{"title":"End-tidal CO2 and ventilation: Novel markers for assessing performance levels in elite long-distance runners","authors":"Akihiro Sakamoto , Yohei Matsumoto , Hisashi Naito , Chin Moi Chow","doi":"10.1016/j.resp.2024.104389","DOIUrl":"10.1016/j.resp.2024.104389","url":null,"abstract":"<div><div>Well-trained individuals, compared to less well-trained individuals, exhibit a lower minute ventilation (V̇<sub>E</sub>) and higher end-tidal partial pressure of CO<sub>2</sub> (P<sub>ET</sub>CO<sub>2</sub>) at a given work rate. This study investigated whether such breathing adaptations seen in well-trained individuals also applied to elite long-distance runners. Forty-one long-distance runners were categorized into high (<strong>Long-High</strong>, consisting of Tokyo-Hakone College Ekiden [relay marathon] runners and Olympic athletes, n = 23), or low performance-level group <strong>(Long-Low</strong>, n = 18) according to their race times. Ten middle-distance runners (<strong>Middle</strong>) also participated in a comparison group. All subjects performed an incremental exercise test on a motorized treadmill until exhaustion. Maximum V̇O<sub>2</sub> and velocity were greater for the <strong>Long</strong> groups than the <strong>Middle</strong> group, however these measures were not distinguishable between the <strong>Long-High</strong> and the <strong>Long-Low</strong> groups. By contrast, V̇<sub>E</sub> and P<sub>ET</sub>CO<sub>2</sub> were able to identify the <strong>Long-High</strong> group. Submaximal V̇<sub>E</sub> were lowest, whilst P<sub>ET</sub>CO<sub>2</sub> especially at high running velocities were highest for the <strong>Long-High</strong> group. This study confirms that breathing patterns with lower V̇<sub>E</sub> and higher P<sub>ET</sub>CO<sub>2</sub> are relevant adaptation markers for assessing endurance race performance in elite long-distance runners.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"333 ","pages":"Article 104389"},"PeriodicalIF":1.9,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142922777","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}
Pub Date : 2024-12-26DOI: 10.1016/j.resp.2024.104386
Ryan W. Bavis , Matthew D. Danielson , Gemma Dufour , Julia Hanus , Ashley E. Pratt , Kristina E. Tobin
Chronic hyperoxia during early postnatal development depresses breathing when neonatal rats are returned to room air and causes long-lasting attenuation of the hypoxic ventilatory response (HVR). In contrast, little is known about the control of breathing of juvenile or adult mammals after chronic exposure to moderate hyperoxia later in life. Therefore, Sprague-Dawley rats were exposed to 60 % O2 for 7 days (juveniles) or for 4 and 14 days (adults) and ventilation was measured by whole-body plethysmography immediately after the exposure or following a longer period of recovery in room air. Hyperoxia-treated juvenile rats appeared to hypoventilate when returned to room air (11–13 % lower ventilation and CO2 convection requirement relative to age-matched controls), but chronic hyperoxia did not alter normoxic ventilation in adult rats. In contrast, pre-treatment with chronic hyperoxia augmented the HVR in both juvenile rats (+41 %) and adult rats (+28–50 %). The hypercapnic ventilatory response (7 % CO2) also tended to be augmented in adult rats after 14 days of hyperoxia, but this effect was not significant after accounting for variation in metabolic rate (i.e, CO2 convection requirement). These findings confirm that chronic hyperoxia elicits age-specific respiratory plasticity in rats. These age-dependent differences are not caused by a lack of plasticity in adult-exposed rats; rather, there are qualitative differences in the plasticity that is expressed after chronic hyperoxia in neonates, juveniles, and adults as well as differences in its persistence.
{"title":"Respiratory plasticity induced by chronic hyperoxia in juvenile and adult rats","authors":"Ryan W. Bavis , Matthew D. Danielson , Gemma Dufour , Julia Hanus , Ashley E. Pratt , Kristina E. Tobin","doi":"10.1016/j.resp.2024.104386","DOIUrl":"10.1016/j.resp.2024.104386","url":null,"abstract":"<div><div>Chronic hyperoxia during early postnatal development depresses breathing when neonatal rats are returned to room air and causes long-lasting attenuation of the hypoxic ventilatory response (HVR). In contrast, little is known about the control of breathing of juvenile or adult mammals after chronic exposure to moderate hyperoxia later in life. Therefore, Sprague-Dawley rats were exposed to 60 % O<sub>2</sub> for 7 days (juveniles) or for 4 and 14 days (adults) and ventilation was measured by whole-body plethysmography immediately after the exposure or following a longer period of recovery in room air. Hyperoxia-treated juvenile rats appeared to hypoventilate when returned to room air (11–13 % lower ventilation and CO<sub>2</sub> convection requirement relative to age-matched controls), but chronic hyperoxia did not alter normoxic ventilation in adult rats. In contrast, pre-treatment with chronic hyperoxia augmented the HVR in both juvenile rats (+41 %) and adult rats (+28–50 %). The hypercapnic ventilatory response (7 % CO<sub>2</sub>) also tended to be augmented in adult rats after 14 days of hyperoxia, but this effect was not significant after accounting for variation in metabolic rate (i.e, CO<sub>2</sub> convection requirement). These findings confirm that chronic hyperoxia elicits age-specific respiratory plasticity in rats. These age-dependent differences are not caused by a lack of plasticity in adult-exposed rats; rather, there are qualitative differences in the plasticity that is expressed after chronic hyperoxia in neonates, juveniles, and adults as well as differences in its persistence.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"333 ","pages":"Article 104386"},"PeriodicalIF":1.9,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142897112","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}
Pub Date : 2024-12-25DOI: 10.1016/j.resp.2024.104387
Janka Jakusova , Tomas Buday , Daniela Mokra , Romana Barosova , Juliana Hanusrichterova , Marian Adamkov , Veronika Mestanova , Jana Plevkova , Mariana Brozmanova
Background
Allergic rhinitis (AR) is a common cause of chronic cough, linked to dysregulated airway C- and Aδ-fibres through inflammatory mediators. Despite the limited efficacy of current antitussive therapies, recent studies show that the NaV1.7 inhibitor can block cough in naïve guinea pigs. This study aimed to analyse the effect of the NaV1.7 blocker PF-05089771 on cough in guinea pigs with AR.
Methods
Dunkin Hartley guinea pigs were sensitised and challenged with ovalbumin (OVA). Cough was induced using citric acid aerosol (0.4 M) before nasal challenge (NCH), and then one hour after the 1st, 3rd, and 6th NCH. The OVA-inhibitor group was pre-treated with inhaled NaV1.7 blocker (PF-05089771, 100 μM) before tussigen inhalation.
Results
Chronic AR increased cough response to citric acid in both males and females. Pre-treatment with NaV1.7 blocker significantly inhibited cough reflex by ≈ 75 % in males and ≈ 80 % in females without affecting respiratory rate.
Conclusion
NaV1.7 blocker inhalation effectively inhibits cough in guinea pigs with AR.
{"title":"Effectiveness of selective NaV1.7 blocker PF-05089771 in reducing cough associated with allergic rhinitis in guinea pigs","authors":"Janka Jakusova , Tomas Buday , Daniela Mokra , Romana Barosova , Juliana Hanusrichterova , Marian Adamkov , Veronika Mestanova , Jana Plevkova , Mariana Brozmanova","doi":"10.1016/j.resp.2024.104387","DOIUrl":"10.1016/j.resp.2024.104387","url":null,"abstract":"<div><h3>Background</h3><div>Allergic rhinitis (AR) is a common cause of chronic cough, linked to dysregulated airway C- and Aδ-fibres through inflammatory mediators. Despite the limited efficacy of current antitussive therapies, recent studies show that the Na<sub>V</sub>1.7 inhibitor can block cough in naïve guinea pigs. This study aimed to analyse the effect of the Na<sub>V</sub>1.7 blocker PF-05089771 on cough in guinea pigs with AR.</div></div><div><h3>Methods</h3><div>Dunkin Hartley guinea pigs were sensitised and challenged with ovalbumin (OVA). Cough was induced using citric acid aerosol (0.4 M) before nasal challenge (NCH), and then one hour after the 1st, 3rd, and 6th NCH. The OVA-inhibitor group was pre-treated with inhaled Na<sub>V</sub>1.7 blocker (PF-05089771, 100 μM) before tussigen inhalation.</div></div><div><h3>Results</h3><div>Chronic AR increased cough response to citric acid in both males and females. Pre-treatment with Na<sub>V</sub>1.7 blocker significantly inhibited cough reflex by ≈ 75 % in males and ≈ 80 % in females without affecting respiratory rate.</div></div><div><h3>Conclusion</h3><div>Na<sub>V</sub>1.7 blocker inhalation effectively inhibits cough in guinea pigs with AR.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"333 ","pages":"Article 104387"},"PeriodicalIF":1.9,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142897093","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}
Pub Date : 2024-12-25DOI: 10.1016/j.resp.2024.104388
Yaru Liu , Duanyang Li , Tianyi Zhang , Keruo Wang , Xue Liang , Xiaolong Zong , Hong Yang , Zhenyu Li
Background
The primary purpose of this study was to demonstrate the preventive effects of imatinib (IMA) on lipopolysaccharide (LPS)-induced inflammation in a mouse model of acute lung injury (ALI) and human umbilical vascular endothelial cells.
Methods
LPS stimulation for 24 h induced ALI and cell inflammation. The pathological results of the lungs were evaluated using the wet/dry weight ratio, pulmonary vascular permeability measurements, and myeloperoxidase immunohistochemistry. The expression of pro-inflammatory mediators was analyzed using RT-PCR and enzyme-linked immunosorbent assay. Protein levels were analyzed using western blotting. The structure of cell junctions was detected using immunofluorescence.
Results
IMA improved LPS-induced pulmonary pathological damage and reduced the lung wet/dry weight ratio and myeloperoxidase expression in the lung tissue. IMA decreased bronchoalveolar lavage fluid inflammatory cell count and the release of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and monocyte chemotactic protein 1 (MCP-1) in the blood. Pretreatment of human umbilical vascular endothelial cells with IMA significantly attenuated LPS-induced actin stress fiber formation and vascular endothelial-cadherin disruption. In addition, IMA downregulated the mRNA abundances of vascular cell adhesion molecule 1, intercellular adhesion molecule 1, IL-1β, IL-6, and tumor necrosis factor-α(TNF-α) expression. The phosphorylation of p65, nuclear factor-kappa B inhibitor alpha (IκBα), p38, extracellular signal-regulated kinase, and Jun N-terminal kinase induced by LPS were attenuated after IMA treatment in vivo and in vitro.
Conclusions
IMA modulates the nuclear factor-kappa B and mitogen-activated protein kinase signaling pathways and the production of pro-inflammatory cytokines to prevent cellular damage due to LPS infection. These results indicate that IMA may be a potential modulator of LPS-induced ALI.
背景：本研究的主要目的是证明伊马替尼（IMA）对小鼠急性肺损伤（ALI）模型和人脐血管内皮细胞中脂多糖（LPS）诱导的炎症的预防作用。方法：LPS刺激24h诱导ALI和细胞炎症。采用干湿比、肺血管通透性测量和髓过氧化物酶免疫组化评价肺病理结果。采用RT-PCR和酶联免疫吸附法分析促炎介质的表达。western blotting分析蛋白水平。免疫荧光法检测细胞连接结构。结果：IMA改善了lps诱导的肺病理损伤，降低了肺干湿比和肺组织中髓过氧化物酶的表达。IMA降低支气管肺泡灌洗液炎症细胞计数和血液中肿瘤坏死因子-α (TNF-α)、白细胞介素(IL)-6和单核细胞趋化蛋白1 （MCP-1）的释放。IMA预处理人脐血管内皮细胞可显著减弱lps诱导的肌动蛋白应激纤维形成和血管内皮-钙粘蛋白破坏。IMA还下调了血管细胞粘附分子1、细胞间粘附分子1、IL-1β、IL-6 mRNA丰度和肿瘤坏死因子-α(TNF-α)表达。IMA在体内和体外处理后，LPS诱导的p65、核因子- κB抑制剂α (IκBα)、p38、细胞外信号调节激酶和Jun n -末端激酶的磷酸化均减弱。结论：IMA可调节核因子κ B和丝裂原活化蛋白激酶信号通路及促炎细胞因子的产生，预防LPS感染引起的细胞损伤。这些结果表明，IMA可能是lps诱导的ALI的潜在调节剂。
{"title":"Effect of imatinib on lipopolysaccharide‑induced acute lung injury and endothelial dysfunction through the P38 MAPK and NF-κB signaling pathways in vivo and in vitro","authors":"Yaru Liu , Duanyang Li , Tianyi Zhang , Keruo Wang , Xue Liang , Xiaolong Zong , Hong Yang , Zhenyu Li","doi":"10.1016/j.resp.2024.104388","DOIUrl":"10.1016/j.resp.2024.104388","url":null,"abstract":"<div><h3>Background</h3><div>The primary purpose of this study was to demonstrate the preventive effects of imatinib (IMA) on lipopolysaccharide (LPS)-induced inflammation in a mouse model of acute lung injury (ALI) and human umbilical vascular endothelial cells.</div></div><div><h3>Methods</h3><div>LPS stimulation for 24 h induced ALI and cell inflammation. The pathological results of the lungs were evaluated using the wet/dry weight ratio, pulmonary vascular permeability measurements, and myeloperoxidase immunohistochemistry. The expression of pro-inflammatory mediators was analyzed using RT-PCR and enzyme-linked immunosorbent assay. Protein levels were analyzed using western blotting. The structure of cell junctions was detected using immunofluorescence.</div></div><div><h3>Results</h3><div>IMA improved LPS-induced pulmonary pathological damage and reduced the lung wet/dry weight ratio and myeloperoxidase expression in the lung tissue. IMA decreased bronchoalveolar lavage fluid inflammatory cell count and the release of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and monocyte chemotactic protein 1 (MCP-1) in the blood. Pretreatment of human umbilical vascular endothelial cells with IMA significantly attenuated LPS-induced actin stress fiber formation and vascular endothelial-cadherin disruption. In addition, IMA downregulated the mRNA abundances of vascular cell adhesion molecule 1, intercellular adhesion molecule 1, IL-1β, IL-6, and tumor necrosis factor-α(TNF-α) expression. The phosphorylation of p65, nuclear factor-kappa B inhibitor alpha (IκBα), p38, extracellular signal-regulated kinase, and Jun N-terminal kinase induced by LPS were attenuated after IMA treatment in vivo and in vitro.</div></div><div><h3>Conclusions</h3><div>IMA modulates the nuclear factor-kappa B and mitogen-activated protein kinase signaling pathways and the production of pro-inflammatory cytokines to prevent cellular damage due to LPS infection. These results indicate that IMA may be a potential modulator of LPS-induced ALI.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"333 ","pages":"Article 104388"},"PeriodicalIF":1.9,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142897090","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}
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