Respiratory Physiology & Neurobiology最新文献

{"title":"Neurophysiological mechanisms of exertional dyspnea in advanced pregnancy: A case study","authors":"Devin B. Phillips ,&nbsp;Christine A. Darko ,&nbsp;Matthew D. James ,&nbsp;Sandra G. Vincent ,&nbsp;Alexandra M. McCartney ,&nbsp;Lara K. Sreibers ,&nbsp;Nicolle J. Domnik ,&nbsp;J. Alberto Neder ,&nbsp;Denis E. O’Donnell","doi":"10.1016/j.resp.2025.104434","DOIUrl":"10.1016/j.resp.2025.104434","url":null,"abstract":"<div><div>The neurophysiological mechanisms of exertional dyspnea in advanced pregnancy remain incompletely understood. This short case report describes the neurophysiological and sensory responses during standardized cardiopulmonary exercise testing (CPET) in one healthy adult female at three timepoints: a) 3 months pre-pregnancy, b) 35 weeks pregnant (third trimester [T3]), and, c) 1 year post-partum. At rest and during exercise, detailed measurements of neurophysiological, gas-exchange and sensory parameters were completed. Compared to both pre-pregnancy and post-partum, ventilatory requirements, electrical activation of the diaphragm (EMGdi, index of inspiratory neural drive) and esophageal pressure swings were higher in T3 throughout exercise. Moreover, at a given work rate, perceived dyspnea was greater in T3 compared with pre-pregnancy and post-partum and increased in close association with heightened EMGdi throughout exercise. At peak exercise in T3, dyspnea/ventilation and EMGdi/ventilation ratios were greater, compared with pre-pregnancy and post-partum. Compared with pre-pregnancy, EMGdi and perceived dyspnea were greater post-partum near the limits of exercise tolerance, secondary to earlier onset of respiratory compensation-mediated increases in ventilation. In the current case, advanced pregnancy was associated with markedly elevated ratings of dyspnea and lower exercise capacity during a standardized clinical CPET. At submaximal intensities, the heightened dyspnea reflected the awareness of pregnancy-induced increases in ventilatory requirements, inspiratory neural drive, and respiratory muscle effort. At the limits of tolerance, heightened dyspnea and inspiratory neural drive reflected a complex combination of increase ventilatory requirements and mechanical constraints on tidal volume expansion. Compared with pre-pregnancy, residual activity-related dyspnea 1-year post-partum appears to reflect physical deconditioning.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104434"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867713","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":"Measurement of gas exchange surface area from DLNO and DLCO","authors":"Colin Borland","doi":"10.1016/j.resp.2025.104403","DOIUrl":"10.1016/j.resp.2025.104403","url":null,"abstract":"<div><div>The estimated diffusion coefficients for nitric oxide and carbon monoxide in human plasma and red cells can be inserted into the equations for Fick’s 1st and 2nd laws. The surface area of the alveolar membrane and exposed red cells can then be calculated from D_LNO and D_LCO (in hyperoxia). This yields a value of 18.7 m² for alveolar capillary membrane via D_LNO, 19.6 m² for red cell surface area via D_LCO in a seated human at rest and = 2.03m² for a membrane oxygenator. The values for a seated human are substantially less than morphometric values. This is likely due to a considerable functional reserve in the lung.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104403"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143426062","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}

{"title":"Phrenic motor output following acute hyperbaric oxygen exposure","authors":"Prajwal P. Thakre ,&nbsp;Kyle M. Deegan ,&nbsp;David D. Fuller","doi":"10.1016/j.resp.2025.104399","DOIUrl":"10.1016/j.resp.2025.104399","url":null,"abstract":"<div><div>We studied adult male rats to determine if phrenic motor output is altered following acute hyperbaric oxygen (HBO) pretreatment. Rats were treated with 1-h of 100 % O₂ at 2 atmospheres (HBO, n = 12) or 21 % O₂ at 1 atmosphere (normoxia, n = 12) and then anesthetized and ventilated to enable phrenic nerve recordings. Baseline phrenic output and blood pressure were similar between groups. Sixty minutes after exposure to acute intermittent hypoxia (AIH), inspiratory phrenic burst amplitude was +66 ± 47 (HBO) and +43 ± 13 % baseline (normoxia). Thus, both groups expressed phrenic long-term facilitation, pLTF (time effect, P = 0.008). The pLTF magnitude had a larger coefficient of variation after HBO (71 %) <em>vs</em>. normoxia (30 %). This resulted from a bimodal data distribution, with 4 of 12 HBO rats showing pLTF &gt; +70 % baseline (<em>vs.</em> 0 of 12 normoxia). We conclude that acute HBO does not impact baseline phrenic output in this preparation, but further study of HBO and phrenic neuroplasticity is warranted.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104399"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374521","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":"Breathing pattern and ventilatory response to exercise in patients with Chronic Obstructive Pulmonary Disease","authors":"Rocco Accogli ,&nbsp;Annalisa Frizzelli ,&nbsp;Olha Bondarenko ,&nbsp;Panagiota Tzani ,&nbsp;Luigino Calzetta ,&nbsp;Alessandra Marchese ,&nbsp;Roberta Pisi ,&nbsp;Gaetano Caramori ,&nbsp;Alfredo Chetta ,&nbsp;Marina Aiello","doi":"10.1016/j.resp.2025.104413","DOIUrl":"10.1016/j.resp.2025.104413","url":null,"abstract":"<div><h3>Background</h3><div>Patients with Chronic Obstructive Pulmonary Disease (COPD) show ventilatory limitation to exercise due to dynamic hyperinflation (DH). Breathing pattern can be expressed by T_I/T_TOT (inspiratory time/total time) and V_T/T_I (tidal volume/inspiratory time). Both parameters significantly increase during exertional hyperpnea in healthy subjects, but they have never been studied in COPD. In a large cohort of COPD patients, we analysed T_I/T_TOT and V_T/T_I at rest and during maximal exercise.</div></div><div><h3>Methods</h3><div>We enrolled clinically stable COPD patients with wide degree of airflow obstruction. All participants underwent spirometry and cardiopulmonary exercise testing (CPET) on a cycle ergometer.</div></div><div><h3>Results</h3><div>In 234 COPD patients (75 females; age range 41–89 years), T_I/T_TOT and V_T/T_I values significantly increased during exercise, from 0.259 ± 0.040–0.304 ± 0.038 and from 854.1 ± 229,6 ml/s to 2100 ± 622.5 ml/s respectively (p &lt; 0.05). T_I/T_{TOT peak} and V_T/T_{I peak} were positively related (p &lt; 0.05) with VO_2peak (ml/min/kg), maximal workload (Watt). T_I/T_{TOT peak}, but not V_T/T_{I peak} values showed a positive correlation (p &lt; 0.05) with the peak-rest difference of inspiratory capacity (ΔIC, in ml). When related to minute ventilation T_I/T_TOT and V_T/T_I rest values in patients with DH (ΔIC ≥150 ml), compared with those without DH, did not differ between the two groups, though T_I/T_TOT, but not V_T/T_I values, significantly increased during exercise in patients without DH</div></div><div><h3>Conclusions</h3><div>T_I/T_TOT and V_T/T_I values significantly increase during maximal exercise in COPD. T_I/T_TOT values were significantly correlated with dynamic hyperinflation. Our results suggest that T_I/T_TOT and V_T/T_I assessment may provide further information on exercise ventilatory limitation in COPD.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104413"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143458969","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":"Effect of ambient temperature on dexmedetomidine-induced metabolic and cardiorespiratory suppression in spontaneously breathing newborn rats","authors":"Eishi Nakamura,&nbsp;Nana Sato Hashizume,&nbsp;Hinata Kubota,&nbsp;Ryoji Ide,&nbsp;Chikako Saiki","doi":"10.1016/j.resp.2025.104401","DOIUrl":"10.1016/j.resp.2025.104401","url":null,"abstract":"<div><div>Newborn animals are known to increase the ventilation–metabolism ratios in hypoxia, particularly at cold environment by decreasing the thermogenesis. We examined whether ambient temperatures and thermoregulatory suppression due to dexmedetomidine, an α₂ adrenoceptor agonist, affect the coupling between ventilation and metabolism in neonatal rats. Wistar rats (3–7 days old) were measured for metabolic and cardiorespiratory indices. Control recordings were made at 34 °C ambient temperature (Ta) and Ta was either kept at 34 °C (Medium), reduced to 27 °C (Low) or increased to 39 °C (High). Once at the desired Ta, the rats were administered normal saline or dexmedetomidine (50 μg∙kg⁻¹) and the indices were again recorded. Control values were comparable between the normal saline and dexmedetomidine groups. Using values relative to the control values in each group, body temperature (Low or High vs. Medium Ta) and heart rate (Low vs. High Ta) were significantly different among the three Ta. At each Ta, the dexmedetomidine group showed significantly lower metabolic rates, minute ventilation, respiratory rate and heart rate, compared to the normal saline group. Despite these changes, the ventilation<img>metabolism ratios in the dexmedetomidine group were comparable at the Medium and Low Ta, and significantly lower at the High Ta, compared to the normal saline group. Dexmedetomidine plus atipamezole (5 mg∙kg⁻¹, an α₂ adrenoceptor antagonist) did not affect the ventilation–metabolism ratios at the Low and High Ta. Although dexmedetomidine suppresses thermoregulatory responses, the coupling of ventilation and metabolic rates can be preserved through α₂ adrenoceptor activation at cold, but not at hot, ambient temperature. Our results suggest that α₂ adrenoceptor activation impairs control of ventilation at heating or rewarming in newborn rats.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104401"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143256574","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}

{"title":"Modulating respiratory mechanics and inflammation in hepatopulmonary syndrome: Aerobic exercise as a therapeutic strategy","authors":"César Augusto Melo-Silva ,&nbsp;Walter Moreno Campos Nunes ,&nbsp;Eloisa Sanches Pereira Nascimento ,&nbsp;Eduardo Marques Guerra ,&nbsp;Marcello Rodrigues Roza ,&nbsp;Suellen Silva-Costa ,&nbsp;Wilcelly Machado-Silva ,&nbsp;Gleiciane Gontijo Avelar ,&nbsp;Otávio Toledo Nóbrega ,&nbsp;Veronica Moreira Amado","doi":"10.1016/j.resp.2025.104410","DOIUrl":"10.1016/j.resp.2025.104410","url":null,"abstract":"<div><h3>Introduction</h3><div>Aerobic exercise training positively modulates the immune system and improves lung function; however, its effects on respiratory system’s elastic, resistive properties and interleukin-10 (IL-10) concentration in hepatopulmonary syndrome (HPS) remains unexplored. This study aimed to assess whether moderate-intensity aerobic (AE) training altered exercise capacity, respiratory mechanics and lung inflammation.</div></div><div><h3>Material and methods</h3><div>Wistar rats were randomly assigned to SHAM, HPS, HPS + AE4, and HPS + EA8 groups. The EA4 group represents AE training for 4 weeks starting 7 days after HPS induction, whereas EA8 accounts for AE training for 4 weeks before and after HPS induction, both protocols practiced 3 times weekly. Exercise capacity, respiratory mechanics, lung and systemic inflammation, and lung morphology were assessed.</div></div><div><h3>Results</h3><div>Moderate aerobic exercise significantly increased the maximal running capacity of the HPS animals. The training decreased tissue elastance by 19 % (p = 0.01 compared to SHAM) and reduced frequency-dependent respiratory reactance at 0.5 Hz, 0.75 Hz, and 1.25 Hz frequencies compared to HPS animals (p &lt; 0.05 for all). For the HPS + EA4 and HPS + EA8 groups IL-10 plasma concentration increased by 23 % and 31 % compared to SHAM (p &lt; 0.001 both) and by 38 % and 47 % compared to HPS (p &lt; 0.01 both). Nonetheless, AE did not alleviate lung tissue remodeling induced by HPS.</div></div><div><h3>Conclusions</h3><div>Moderate-intensity aerobic training improved maximum running capacity, reduced HPS-induced respiratory mechanics derangements at the lung regional level, and increased systemic IL-10 concentration, although it did not ameliorate lung tissue remodeling.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104410"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403610","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":"Muscle oxygenation and local blood volume difference between intercostal and deltoid during dry static apnea in breath-hold divers","authors":"Dario Vrdoljak ,&nbsp;Željko Dujić ,&nbsp;Colin D. Hubbard ,&nbsp;Geoff B. Coombs ,&nbsp;Andrew T. Lovering ,&nbsp;Ivan Drvis ,&nbsp;Nikola Foretic ,&nbsp;Joseph W. Duke","doi":"10.1016/j.resp.2025.104402","DOIUrl":"10.1016/j.resp.2025.104402","url":null,"abstract":"<div><div>During either a static or dynamic apnea, oxygen is delivered to vital organs, i.e., the brain and heart, and there is a compensatory reduction of oxygen consumption in peripheral tissues. Additionally, maximal apnea is characterised by the initial easy-going phase and subsequent struggle phase in which involuntary breathing movements appear. The aim of this study was to compare the oxygenation and local blood volume of one active (external intercostal) and one non-active (deltoid) muscle during maximal dry static apneas in breath-hold divers while supine. Thirteen breath-hold divers performed 3 preparatory apneas followed by 3 maximal apneas with 5 min of supine rest between each apnea. During all apneas (duration, 115–323 s; IBM, 7–35) muscle oxygenation and muscle blood volume change were measured via NIRS. The variables quantified were muscle oxygen saturation (SmO₂) and total hemoglobin (tHb). We found that the decline in oxygen saturation was similar in external intercostals and deltoids, even though their physiological role during a breath-hold is different. However, the external intercostals re-saturated at a significantly higher rate following a maximal apnea than the deltoid muscle (p = 0.02). Also, during the apneas, there was a significantly different response between muscles, where external intercostals had an increase and deltoid a decrease in tHb (p = 0.01). These findings indicate that despite respiratory muscle activity resulting from IBMs during breath-holds external intercostal muscle re-oxygenation occurs faster than peripheral muscles which may allow for a faster return to normal breathing.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104402"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374564","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":"Cockroach allergen exposure alters redox homeostasis and mediates airway inflammation","authors":"Swati Sharma ,&nbsp;Ekta Nagar ,&nbsp;Naveen Arora","doi":"10.1016/j.resp.2025.104438","DOIUrl":"10.1016/j.resp.2025.104438","url":null,"abstract":"<div><div>Allergic diseases are orchestrated by complex interplay of allergens with components of immune system as well as structural cells. As airway epithelium lies at the interface of environment and host immune responses, therefore we sought to study role of cockroach allergen exposure in context of oxidative stress in epithelia and its functional role in allergic pathophysiology. In vitro studies on Beas2B cells indicated elevation of intracellular ROS levels upon cockroach allergen (CE) exposure and transcriptional regulation of epithelial activation markers (CXCL-8 and IL-1 α) and endogenous antioxidant SOD-2. To corroborate ROS induction in vivo, mice model of cockroach hypersensitivity was generated and cytosolic and mitochondrial superoxide levels in lung of mice were estimated along with markers of allergic inflammation (cellular infiltration and epithelial activation cytokines (IL-33, TSLP and IL-25), proinflammatory (Th2 cytokines) and antioxidant pathways. Antioxidant supplementation with NAC, GSH and mitochondria specific ROS scavenger Mito-Tempo significantly reduced allergic inflammation. To discern the role of antioxidant pathways, we examined Nrf2 and SOD2 levels in mice lungs. Our results indicate that cockroach allergen exposure offsets the redox balance in lung with reduced glutathione peroxidase and catalase levels, however antioxidant treatment was able to restore redox equilibrium in lung by upregulating the expression of major regulator of antioxidant signalling, Nrf2 and enzymatic antioxidant SOD2. Our studies indicate crucial role of cockroach allergen induced ROS in allergic pathophysiology and targeting allergen induced oxidative stress may be utilised as an adjunct therapy for allergic diseases.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104438"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878136","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":"Biological sex differences in the perception of CO2-induced air hunger","authors":"Louis M. Hall,&nbsp;Graham R. Sharpe,&nbsp;Neil C. Williams,&nbsp;Michael A. Johnson","doi":"10.1016/j.resp.2025.104436","DOIUrl":"10.1016/j.resp.2025.104436","url":null,"abstract":"<div><h3>Introduction</h3><div>Biological sex may mediate ‘dyspnoea’ during submaximal exercise, but whether it mediates air hunger (AH), a highly unpleasant form of dyspnoea, remains unclear.</div></div><div><h3>Method</h3><div>Forty healthy adults (twenty females) completed 6-min of quiet breathing (rest) followed by a hyperoxic CO₂ rebreathing task to evoke AH. AH intensity (AH-I) and unpleasantness (AH-U) were measured every 30-s. The Multidimensional Dyspnoea Profile (MDP) was administered after CO₂ rebreathing.</div></div><div><h3>Results</h3><div>Compared to males, AH-I and AH-U thresholds occurred at lower PETCO₂ in females (AH-I: 44.15 ± 2.81 vs 48.90 ± 4.47 mmHg, <em>P</em> &lt; 0.001; AH-U: 43.86 ± 2.57 vs 47.59 ± 2.75 mmHg, <em>P</em> &lt; 0.001) and after a smaller increase in PETCO₂ above resting PETCO₂ (AH-I: 7.04 ± 2.63 vs 10.08 ± 5.28 mmHg, <em>P</em> = 0.027; AH-U: 6.75 ± 2.22 vs 8.77 ± 2.99 mmHg, <em>P</em> = 0.020). AH-I and AH-U were higher in females than males at standardised absolute V̇_E of 25, 30 and 35 L/min (<em>P</em> &lt; 0.05). AH-U, but not AH-I, remained higher (main effect of sex, <em>P</em> = 0.026) in females than males at standardised relative V̇_E of 20, 25, and 30 % MVV. More females (<em>n</em> <em>=</em> 9) than males (<em>n=</em> 4) terminated CO₂ rebreathing due to maximal AH perception (<em>P</em> = 0.001). Compared to males, females reported greater intensities of ‘mental effort/concentration’ (7 ± 3 vs 4 ± 3), ‘tight/constricted lungs’ (6 ± 3 vs 2 ± 2), and ‘breathing work/effort’ (6 ± 2 vs 4 ± 3) (all <em>P</em> &lt; 0.05) on the MDP.</div></div><div><h3>Conclusion</h3><div>Our findings suggest that sex differences exist in the perception of AH, which are not entirely accounted for by sex differences in ventilatory capacity.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"335 ","pages":"Article 104436"},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877112","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":"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 ,&nbsp;Mariana Brozmanova ,&nbsp;Janka Jakusova ,&nbsp;Zuzana Biringerova ,&nbsp;Lukas Martvon ,&nbsp;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":"2025-05-01","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}