Respiratory Physiology & Neurobiology最新文献_第3页

AAV9 gene therapy to target respiratory insufficiency in the D2.mdx mouse model of duchenne muscular dystrophy AAV9基因治疗D2患者呼吸功能不全。mdx小鼠杜氏肌营养不良模型。

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-02-01 Epub Date: 2025-11-14 DOI: 10.1016/j.resp.2025.104513

Debolina D. Biswas , Nicolas H. Han , Marán Y. Hernández Rodríguez, Jane Lee, Sarra M. Abdelbarr, Evelyn R. Scarrow, Mai K. ElMallah

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder caused by a deficiency of dystrophin. Dystrophin deficiency leads to progressive muscle weakness, including involvement of the respiratory muscles, ultimately resulting in respiratory failure. Adeno-associated virus (AAV)-mediated gene therapy carrying a microdystrophin (µDys) transgene was recently approved by the Food and Drug Administration (FDA); however, its effects on the respiratory system remain unclear. Further, effective transduction of all muscle groups requires high systemic AAV doses, which are associated with dose-dependent toxicities. In this study, we investigated whether respiratory-directed gene therapy can 1) specifically target respiratory muscles and (2) reduce the total AAV-µDys dose required for therapeutic benefit. We compared the efficiency of AAV9-µDys delivery using different administration routes and dosages in D2.mdx mice, a mouse model of DMD. AAV9-µDys was administered either systemically at a high dose, locally at intermediate doses via intralingual and intrathoracic injections, or through a combination of systemic and respiratory-directed intermediate dosing. All treatments resulted in improved respiratory muscle dystrophin expression and decreased pathology; however, the intermediate and combination dosing led to lower liver vector genome expression. In conclusion, respiratory-targeted gene therapy can improve respiratory muscle pathology while reducing the need for high systemic AAV doses associated with liver toxicity.

杜氏肌营养不良症（DMD）是一种由肌营养不良蛋白缺乏引起的x连锁隐性疾病。肌营养不良蛋白缺乏会导致进行性肌肉无力，包括累及呼吸肌，最终导致呼吸衰竭。携带微营养不良蛋白（µDys）转基因的腺相关病毒（AAV）介导的基因治疗最近获得了美国食品和药物管理局（FDA）的批准；然而，它对呼吸系统的影响尚不清楚。此外，所有肌群的有效转导需要高的全身AAV剂量，这与剂量依赖性毒性有关。在这项研究中，我们研究了呼吸导向基因治疗是否可以1)特异性靶向呼吸肌，(2)减少治疗获益所需的总AAV-µDys剂量。我们比较了不同给药途径和给药剂量下AAV9-µDys在D2中的递送效率。mdx小鼠，DMD小鼠模型。AAV9-µDys采用高剂量全身性给药、舌内和胸内局部中剂量给药或全身和呼吸定向中剂量联合给药。所有治疗均改善了呼吸肌肌营养不良蛋白的表达，降低了病理水平；然而，中间剂量和联合剂量导致肝脏载体基因组表达降低。总之，呼吸靶向基因治疗可以改善呼吸肌病理，同时减少与肝毒性相关的高系统性AAV剂量的需要。

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引用次数: 0

Oscillation mechanics in adults with cystic fibrosis: Effect of airway obstruction and detection of early dysfunction 囊性纤维化成人的振荡力学：气道阻塞的影响和早期功能障碍的检测

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-02-01 Epub Date: 2025-12-11 DOI: 10.1016/j.resp.2025.104526

Caroline O. Ribeiro , Cíntia M.S. Sousa , Manuela G. Torres , Raphael F.J. Oliveira , Agnaldo J. Lopes , Pedro L. Melo

Respiratory oscillometry can help understand pathophysiological changes and detect early abnormalities. However, little is known about oscillometry in adult individuals with cystic fibrosis (CF). This research examines the emerging role of respiratory oscillometry in the context of groups of adult CF patients associated with greater severity. The contributions to our understanding of the respiratory abnormalities along the course of increasing severity and the diagnostic use of this method were also evaluated.

This cross-sectional study was conducted in 15 individuals with no history of smoking or pulmonary diseases (control group), and 52 individuals with diagnoses of CF were studied, being classified into 10 normal to the spirometric exam, 14 mild, 16 moderate, and 12 severe cases. The mean age of the patients was 25.2 years.

Airway obstruction resulted in increased values of resistance at 4 Hz (R4, Kruskal-Wallis, p = 0.0002), 12 Hz (R12, p = 0.0032), and resistance dependence (R4-R20, p < 0.0001). Similar analysis revealed reductions in dynamic compliance (Cdyn, p < 0.0001) and ventilation homogeneity, as assessed by resonance frequency (fr, p < 0.0001) and reactance area (Ax, p < 0.0001). Respiratory work, as measured by the impedance modulus, also showed increased values (Z4, p < 0.0001). Oscillometric indexes showed moderate to good correlations with spirometric and plethysmographic parameters. The early abnormalities in mild airway obstruction were detected by fr and Ax with adequate accuracy (AUC>0.70). At the same time, R4-R20, fr, and Ax achieved high diagnostic accuracy (AUC>0.95) in diagnosing late-stage respiratory changes. We conclude that 1) airflow obstruction in adults with CF introduces significant changes in the resistive and reactive properties of the respiratory system compared with healthy subjects; 2) these changes are proportional to airway obstruction; and 3) oscillometry provides novel information suitable to facilitate the diagnosis of respiratory abnormalities in adults with CF.

呼吸振荡测量可以帮助了解病理生理变化和发现早期异常。然而，对囊性纤维化（CF）成人个体的振荡测量知之甚少。本研究探讨了呼吸振荡测量法在与严重程度相关的成年CF患者组中的新作用。对我们对呼吸异常随着严重程度的增加而增加的认识以及该方法的诊断应用的贡献也进行了评估。本横断面研究选取了15例无吸烟史或肺部疾病的个体（对照组），52例诊断为CF的个体进行研究，肺活量检查分为正常至正常10例，轻度14例，中度16例，重度12例。患者平均年龄25.2岁。气道阻塞导致4 Hz （R4, Kruskal-Wallis, p = 0.0002）、12 Hz （R12, p = 0.0032）和阻力依赖性（R4- r20, p <； 0.0001）的阻力值升高。类似的分析显示，通过共振频率（fr, p <； 0.0001）和电抗面积（Ax, p <； 0.0001）评估，动态顺应性（Cdyn, p <； 0.0001）和通风均匀性降低。通过阻抗模量测量的呼吸功也显示出增加的值（Z4, p <； 0.0001）。振荡指标与肺活量测定和容积描记参数表现出中度至良好的相关性。fr和Ax检测轻度气道阻塞的早期异常具有足够的准确性（AUC>0.70）。同时，R4-R20、fr、Ax在诊断晚期呼吸变化方面具有较高的诊断准确率（AUC>0.95）。我们得出结论：1)与健康受试者相比，CF成人气流阻塞导致呼吸系统的阻力和反应特性发生显著变化；2)这些变化与气道阻塞成正比；3)振荡测量法提供了适合于诊断成人CF呼吸异常的新信息。

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引用次数: 0

Development of periodic breathing in awake healthy individuals under controlled progressive hypoxia 控制进行性缺氧下健康个体周期性呼吸的发展

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-02-01 Epub Date: 2025-11-14 DOI: 10.1016/j.resp.2025.104512

D. van Scheppingen , M. de Haan , M. Gerrits , STJ van der Landen , GM Lötgerink , R. De Jongh , R. Bezemer

The aim of this study was to better understand the ventilatory response to controlled progressive hypoxia in healthy individuals and identify factors influencing the development of periodic breathing under hypoxic conditions. The study was conducted in a hypoxia room at the Complementary Medical Centre in Genk, Belgium. Eighteen healthy participants were subjected to controlled progressive hypoxia, with oxygen levels ranging from 0.21 to 0.10. Oxygen saturation (SpO₂) was measured using a Nellcor® PM10N pulse oximeter, and carbon dioxide levels, including end-tidal carbon dioxide (EtCO₂), were monitored using a Philips LoFlo® sidestream device. Recorded data of SpO₂ sensor and capnography were analyzed whether sex, age, and Body Mass Index (BMI) were factors influencing the participants’ ventilatory response to hypoxic conditions.

Results

showed that 22 % of the study participants developed periodic breathing, all of whom were men, particularly older individuals, with an average age of 40.0 ± 16.2 years (p = 0.026). There was a notable sex-specific response, with 100 % of periodic breathing cases being male (p = 0.078). Significant correlations were found within the periodic breathing group: BMI correlated with the SpO₂ value at the start of PB (R²=0.987, p = 0.013), the pulse rate at the start of periodic breathing (R²=-0.992, p = 0.008), and the EtCO₂ at the end of the first breath after the apneic phase (R²=0.908, p = 0.092). These findings indicate that sex, age, and BMI are critical factors in determining an individual's ventilatory response to hypoxic conditions. Periodic breathing developed exclusively in men, and the physiological state at the onset of periodic breathing, measured by the SpO₂ and pulse rate, was significantly correlated with BMI.

本研究的目的是为了更好地了解健康个体对控制性进行性缺氧的通气反应，并确定影响缺氧条件下周期性呼吸发展的因素。这项研究是在比利时根克补充医疗中心的一个缺氧室进行的。18名健康的参与者接受了控制进行性缺氧，氧气水平从0.21到0.10不等。使用Nellcor®PM10N脉搏血氧仪测量氧饱和度（SpO2），使用Philips LoFlo®侧流装置监测二氧化碳水平，包括潮末二氧化碳（EtCO2）。分析SpO2传感器和血管造影记录的数据，性别、年龄和身体质量指数（BMI）是否是影响参与者缺氧条件下通气反应的因素。结果：22%的研究参与者出现周期性呼吸，全部为男性，特别是老年人，平均年龄为40.0±16.2岁（p=0.026）。有显著的性别特异性反应，100%的周期性呼吸病例为男性（p=0.078）。在周期性呼吸组中，BMI与PB开始时的SpO2值（R2=0.987, p=0.013）、周期性呼吸开始时的脉搏率（R2=-0.992, p=0.008）、窒息期后第一次呼吸结束时的EtCO2 （R2=0.908, p=0.092）相关。这些发现表明，性别、年龄和BMI是决定个体对缺氧条件通气反应的关键因素。周期性呼吸只发生在男性身上，周期性呼吸开始时的生理状态（通过SpO2和脉搏率测量）与BMI显著相关。

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引用次数: 0

Key hemodynamic parameters during induced hypothermia cooling phase in healthy and injured piglets 健康仔猪和受伤仔猪诱导低温冷却阶段的关键血流动力学参数。

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-02-01 Epub Date: 2025-12-08 DOI: 10.1016/j.resp.2025.104525

Lucía Vaamonde , Miguel Martell , Patricia Vollono , Tatiana Gagliardi , Cecilia Fernández , Fernando E. Silvera , M. Fernanda Blasina

Hypoxic-ischemic encephalopathy (HIE) in newborns treated with therapeutic hypothermia(TH) represents a challenge, especially during cooling phase which could be less controlled. This study explored the hemodynamic effects of the cooling phase of TH in a piglet model of perinatal asphyxia with lung injury. Cardiovascular parameters, including systemic arterial pressure (SAP), pulmonary artery pressure (PAP), heart rate (HR), and cardiac output (CO) were monitored from 38.5 to 39.5°C -physiological- to 31.0°C. The piglets were divided into TH without (H, n = 12) and TH with lung injury (Hi, n = 7). Both groups showed decreases in SAP, HR, and CO, more pronounced in Hi. PAP was consistently higher in Hi, though it decreased significantly below 33.5°C (40 % less at 31°C, compared to baseline). Myocardial contractility decreased along the cooling, particularly in Hi group, explaining CO reduction (40 % and 35 % in Hi and H group, respectively). No significant changes were observed in brain monitoring, oxygen extraction ratio, or acid-base status. We concluded that in HIE model, close hemodynamic monitoring during the induction phase of TH as well as monitoring of tissue oxygenation warrants detection of changes, a special challenge when lung injury is developed. Although hemodynamic changes were observed with TH in this model, it was not contraindicated since brain oxygenation was unchanged. These data suggest that TH may be a viable option for human neonates with similar conditions, but further research is essential to evaluate its safety and efficacy in this vulnerable population.

治疗性低温（TH）治疗新生儿缺氧缺血性脑病（HIE）是一个挑战，特别是在冷却阶段，可以较少控制。本研究探讨了TH冷却期对围产期窒息肺损伤仔猪模型的血流动力学影响。心血管参数，包括全身动脉压（SAP）、肺动脉压（PAP）、心率（HR）和心输出量（CO）在38.5-39.5°C（生理）至31.0°C监测。将仔猪分为未肺损伤组（H, n=12）和肺损伤组（Hi, n=7）。两组均表现出SAP、HR和CO的下降，其中Hi的下降更为明显。Hi患者的PAP始终较高，但在33.5°C以下显著下降（与基线相比，在31°C时降低40%）。心肌收缩力随着冷却而下降，特别是在Hi组，这解释了CO的减少（Hi组和H组分别为40%和35%）。脑监测、氧气提取比或酸碱状态未见明显变化。我们得出结论，在HIE模型中，在TH诱导阶段密切监测血流动力学以及监测组织氧合可以检测到变化，这是肺损伤发生时的特殊挑战。虽然在该模型中观察到TH的血流动力学改变，但由于脑氧合不变，它不是禁忌。这些数据表明，对于有类似情况的人类新生儿，TH可能是一种可行的选择，但需要进一步的研究来评估其在这一脆弱人群中的安全性和有效性。

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引用次数: 0

Diethelm Richter (1943–2025): A life in respiratory neurobiology Diethelm Richter(1943-2025)：呼吸神经生物学的一生。

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-02-01 Epub Date: 2025-11-25 DOI: 10.1016/j.resp.2025.104524

K. Michael Spyer, Julian F.R. Paton

引用次数: 0

Gas exchange dynamics and responses to exercise in chronic thromboembolic pulmonary hypertension 慢性血栓栓塞性肺动脉高压的气体交换动力学和运动反应。

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-01-01 Epub Date: 2025-09-18 DOI: 10.1016/j.resp.2025.104490

Camila Melo Coelho Loureiro , Eloara V.M. Ferreira , Rudolf K.F. Oliveira , Andrei Augusto Assis de Campos Cordeiro , Elaine Brito Vieira , Meliane de Oliveira Daud , Ivan Teruaki Ivanaga , Luiz Eduardo Nery , Jaquelina Sonoe Ota-Arakaki , Roberta Pulcheri Ramos

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) is mainly caused by mechanical obstruction by thrombi associated with pulmonary vascular remodeling. Bronchial collateral circulation has been studied as a protective mechanism or implicated in the pathogenesis of microvascular disease, also contributing to changes in gas exchange at rest and during exercise. In this study, we sought to characterize the gas exchange abnormalities in patients with CTEPH with particular attention to bronchopulmonary shunt.

Methods

Prospective, cross-sectional study with diagnostic intervention. After undergoing right heart catheterization, subjects performed a 50 % maximal workload steady-state exercise at room air and receiving 100 % oxygen with a face mask from a Douglas bag. Arterial and mixed venous blood samples were obtained for gas analysis and calculation of shunt.

Results

Data from 14 subjects (7 women, 49 ± 15 years) with CTEPH were analyzed. All participants showed an increased shunt volume/fraction detected by 100 % oxygen breathing at rest that decreased during exercise (17.0 ± 3.6 % versus 9.8 ± 3.0 %; P < 0.001). Shunt fraction was negatively correlated with hemodynamic severity at rest, degree of pulmonary vascular obstruction and dilation of the pulmonary artery trunk. A drop in PaO₂ was observed in 71 % of patients with RVP > 750 dynes.s.cm⁵, compared to 14 % among those with less severe hemodynamic profile. Multiple linear regression analysis revealed that both PVR and the Qanadli score were independently associated with bronchopulmonary shunt fraction during exercise.

Conclusion

Bronchopulmonary shunt seems to be an adaptive mechanism in CTEPH at rest and during exercise.

背景：慢性血栓栓塞性肺动脉高压（CTEPH）主要由与肺血管重构相关的血栓机械性阻塞引起。支气管侧枝循环作为一种保护机制或参与微血管疾病的发病机制，也有助于休息和运动时气体交换的变化。在这项研究中，我们试图描述CTEPH患者的气体交换异常，特别关注支气管肺分流。方法：前瞻性、横断面研究和诊断干预。在接受右心导管插管后，受试者在室内空气中进行50%最大负荷稳态运动，并在道格拉斯袋面罩下接受100%氧气。取动脉血和混合性静脉血进行气体分析和分流计算。结果：分析了14例CTEPH患者（7例女性，49±15岁）的数据。所有参与者在休息时100%氧气呼吸检测到的分流体积/分数增加，在运动期间下降（17.0±3.6% vs 9.8±3.0%;P 750 dydys）。而在血流动力学不太严重的患者中，这一比例为14%。多元线性回归分析显示PVR和Qanadli评分与运动时支气管肺分流分数独立相关。结论：支气管肺分流可能是静止和运动时CTEPH的一种适应性机制。

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引用次数: 0

Comparison of maximal inspiratory pressure to resistive breathing for weaning prediction 最大吸气压力与阻力呼吸在脱机预测中的比较。

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-01-01 Epub Date: 2025-09-27 DOI: 10.1016/j.resp.2025.104498

Apostolos A. Menis , Vasiliki Tsolaki , Maria E. Papadonta , Vasileios Vazgiourakis , Konstantinos Mantzarlis , Epaminondas Zakynthinos , Demosthenes Makris

Introduction

The effect of MIP on extravascular lung water generation (EVLW) is not known. Our aim was to compare a resistive breathing trial (RBT) to MIP in terms of EVLW generation and in predicting the weaning outcome.

Methods

In patients undergoing a spontaneous breathing trial (SBT) for the first time we compared the EVLW generated, using lung ultrasound (B-lines), during MIP to SBT and RBT; MIP, airway pressure swings during RBT (ΔPaw_RBT) and its ratio to rapid shallow breathing index during RBT (ΔPaw/RSBI)_RBT were assessed as indices of weaning prediction. Additionally, we assessed the relationship of MIP, ΔPaw_RBT and (ΔPaw/RSBI)_RBT to esophageal (Pes) and transdiaphragmatic pressure (Pdi) and the pressure-time product of the Pes (PTPes). Weaning failure was defined as SBT failure or need for reintubation at 48 h.

Measurement and main results

Thirty-three patients were enrolled. B-lines, heart rate and blood pressure were higher during MIP compared to RBT (p < 0.001). ΔPaw_RBT, (ΔPaw/RSBI)_RBT and MIP were higher in patients succeeding weaning compared to those who failed [19.53 cmH₂O (±11.91) vs 10.77 cmH₂O (±8.94), p = 0.027], [0.16 cmH₂O·L·min⁻¹ (0.16) vs 0.05 cmH₂O·L·min⁻¹ (0.03), p < 0.001)], [41.39 cmH₂O (14.59) vs 16.34 cmH₂O (20.3), p = 0.002]. ROC analysis showed no difference between MIP and ΔPaw_RBT or (ΔPaw/RSBI)_RBT in predicting weaning outcome; ΔPaw_RBT and (ΔPaw/RSBI)_RBT correlated with Pes, Pdi and PTPes (p < 0.05).

Conclusions

(ΔPaw/RSBI)_RBT predicted weaning outcome with similar accuracy to MIP and was associated with less B-lines, HR and BP alterations; RBT-derived airway pressures are a promising novel method for weaning outcome prediction and respiratory muscle strength assessment.

MIP对血管外肺水生成（EVLW）的影响尚不清楚。我们的目的是比较阻力呼吸试验（RBT）与MIP在EVLW产生和预测脱机结果方面的差异。方法：在首次进行自主呼吸试验（SBT）的患者中，我们比较了MIP期间使用肺超声（b线）与SBT和RBT产生的EVLW；评估MIP、RBT期间气道压力波动（ΔPawRBT）及其与RBT期间快速浅呼吸指数（ΔPaw/RSBI）的比值（RBT）作为预测脱机的指标。此外，我们还评估了MIP、ΔPawRBT和（ΔPaw/RSBI）RBT与食管（Pes）和经膈压力（Pdi）以及pe （PTPes）的压力-时间积的关系。脱机失败定义为SBT失败或需要在48小时内重新插管。测量和主要结果：33例患者入组。与RBT相比，MIP期间的b线，心率和血压更高（pRBT, （ΔPaw/RSBI））断奶后患者的RBT和MIP高于失败患者[19.53 cmH2O（±11.91）vs 10.77 cmH2O（±8.94），p=0.027], [0.16 cmH₂O·L·min毒血症（0.16）vs 0.05 cmH₂O·L·min毒血症（0.03），p2O (14.59) vs 16.34 cmH2O (20.3), p=0.002]。ROC分析显示MIP与ΔPawRBT或（ΔPaw/RSBI）RBT在预测断奶结局方面无差异；ΔPawRBT和（ΔPaw/RSBI）RBT与Pes、Pdi和PTPes相关(p结论：（ΔPaw/RSBI）RBT预测断奶结局的准确性与MIP相似，且与较少的b线、HR和BP变化相关；rbt衍生的气道压力是预测脱机结果和评估呼吸肌力量的一种有前途的新方法。

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引用次数: 0

The change in phase shift between respiratory oscillations of mean arterial pressure and heart rate in head-up tilt test: The effect of simulated microgravity 平头倾斜试验中平均动脉压和心率呼吸振荡相移的变化：模拟微重力的影响。

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-01-01 Epub Date: 2025-10-27 DOI: 10.1016/j.resp.2025.104509

Anatoly S. Borovik , Roman Yu. Zhedyaev , Vladimir O. Negulyaev , Kirill A. Bogotskoy , Viktoriia A. Iashina , Elena S. Tomilovskaya , Olga S. Tarasova , Olga L. Vinogradova

Purpose

We studied the synchronization of mean arterial pressure (MAP) and heart rate (HR) high frequency (HF) respiratory oscillations in young men in the supine position and during head-up tilt (HUT), and then analyzed the effect of blood redistribution on these parameters in the lower body negative pressure (LBNP) test, sit-to-stand test and HUT test performed after a 7-day dry immersion (DI, on-ground model of microgravity).

Methods

75 young male volunteers participated in the study. Blood pressure and ECG were continuously recorded, to obtain mean arterial pressure (MAP), heart rate (HR) and wavelet spectra of these parameters. Phases of the oscillations were calculated using Morse analytical wavelets. The synchronization between oscillations was estimated using phase synchronization index (PSI) calculated from Shannon entropy for phase difference distribution histogram.

Results

HUT increased the amplitude of HF MAP waves, but decreased the amplitude of HF waves of HR. The phase shift between HF MAP and HR waves decreased, but the degree of their synchronization increased, as reflected by an increase in the HF peak in PSI spectrum. Similar changes, except for an increase in PSI, were recorded upon exposure to LBNP and in the sit-to-stand test. After 7-day exposure to DI conditions, phase shift between HF MAP and HR oscillations decreased in supine position and then did not change during orthostasis.

Conclusion

The changes in body position, LBNP and dry immersion exposure, which are associated with a decrease in vagal activity, affect the phase relationship between respiratory MAP and HR waves.

目的：研究年轻男性平卧位和平头倾斜（HUT）时平均动脉压（MAP）和心率（HR）高频呼吸振荡的同同性，并在干浸泡（DI，地面微重力模型）7 d后进行下体负压（LBNP）试验、坐立试验和HUT试验时分析血液再分布对这些参数的影响。方法：75名年轻男性志愿者参与研究。连续记录血压和心电图，获得平均动脉压（MAP）、心率（HR）和这些参数的小波谱。用莫尔斯解析小波计算了振荡的相位。根据相位差分布直方图的香农熵计算相同步指数（PSI）来估计振荡之间的同步。结果：HUT增加了HF MAP波的振幅，但降低了HR的HF波振幅。HF MAP和HR波的相移减小，但同步程度增加，体现在PSI谱中HF峰的增加。类似的变化，除了PSI的增加，被记录在暴露于LBNP和坐-站测试。暴露于DI条件7天后，仰卧位时HF MAP和HR振荡之间的相移减小，直立时无变化。结论：体位、LBNP和干浸暴露的改变与迷走神经活动降低有关，影响了呼吸MAP和HR波的相位关系。

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引用次数: 0

Pi-based mechanism of muscle fatigue during all-out exercise in humans 人类全力运动时肌肉疲劳的pi机制

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-01-01 Epub Date: 2025-10-08 DOI: 10.1016/j.resp.2025.104502

Bernard Korzeniewski

The hyperbolic-like decrease with time in power output during all-out exercise (AOE) correlates well with changes in “fatigue-related” metabolites: P_i, H₂PO₄^- (P_i^-) and H⁺. A simple mechanism of muscle fatigue during AOE, named “Pi_peak-P_i-distance” mechanism, is proposed and incorporated into a dynamic computer model of the skeletal muscle bioenergetic system. It involves the dependence of the current power output (PO) on the difference between peak P_i (Pi_peak), at which exercise is terminated because of fatigue in constant-power exercise (CPE), and current P_i. This mechanism can account for several dynamic properties of the skeletal muscle bioenergetic system during AOE, including PO decrease over time, (almost) identical V̇O_2max in AOE and CPE, much faster on-kinetics of V̇O₂ and metabolites than PO in AOE, much faster V̇O₂ on-kinetics in AOE than CPE, much lower V̇O₂ slow component (and higher primary phase II) at the same V̇O_2max in AOE than CPE, different rates of approaching a steady-state by PO in different experiments, the V̇O₂ decrease during AOE after reaching a maximum observed in some experiments and others. The mechanism is also able to explain mechanistically a broad spectrum of system behaviors, including the above-mentioned phenomena. The Pi_peak-P_i-distance mechanism for AOE can be unified with the P_i-double-threshold mechanism proposed previously for CPE (and ramp-incremental exercise, RIE) into the “PiPipeak” mechanism of muscle fatigue. Generally, this unified mechanism, with P_i and Pi_peak as central elements, allows to explain the similarities and differences in fatigue generation in various exercise types.

全力运动（AOE）时功率输出随时间呈双曲线状下降与“疲劳相关”代谢物：Pi、H2PO4- (Pi-)和H+的变化密切相关。提出了一种简单的AOE过程中肌肉疲劳的机制，称为“Pipeak-Pi-distance”机制，并将其纳入骨骼肌生物能量系统的动态计算机模型。它涉及到电流输出（PO）对峰值Pi （Pipeak）和电流Pi之间的差的依赖，峰值Pi是恒功率运动（CPE）中由于疲劳而终止的运动。这一机制可以解释AOE期间骨骼肌生物能量系统的几个动态特性，包括PO随时间的减少，AOE和CPE（几乎）相同的V O2max， AOE中V O2和代谢产物的动力学比PO快，AOE中V O2的动力学比CPE快，AOE中相同V O2max的V O2慢组分比CPE低得多（初级II相更高），不同实验中PO接近稳态的速率不同。在AOE过程中，V （O2）在达到某些实验和其他实验观察到的最大值后下降。该机制还能够从机械上解释广泛的系统行为，包括上述现象。AOE的PiPipeak - pi -distance机制可以与之前提出的CPE的pi -双阈值机制（以及坡道增量运动，RIE）统一为肌肉疲劳的“PiPipeak”机制。一般来说，这种以Pi和Pipeak为中心元素的统一机制可以解释各种运动类型中疲劳产生的异同。

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引用次数: 0

Tobacco smoking: A stimulus for blood volume expansion 吸烟：刺激血容量扩张。

IF 1.6 4区医学 Q3 PHYSIOLOGY

Respiratory Physiology & Neurobiology

Pub Date : 2026-01-01 Epub Date: 2025-10-13 DOI: 10.1016/j.resp.2025.104505

Alexandros Sotiridis , Charalambos Dardamanis-Aidonas , Anastasios Makris , Ioannis Loukas , Nickos Geladas , Maria Koskolou

Tobacco smoking involves the inhalation of carbon monoxide (CO), a gas that binds to hemoglobin molecules to form carboxyhemoglobin (COHb), and thus acutely reduces arterial oxygen content. Whether regular tobacco smoking elicits a compensatory increase in hemoglobin mass (HbM) and concomitant gains in intravascular volumes of even relatively trained individuals was examined in the present study. Thirty young males were split in independent groups based on smoking status (CS; chronic smokers and NS; non-smokers) and aerobic fitness level (MF; more fit and LF; less fit) (CS-MF, CS-LF, NS-MF and NS-LF; n = 8 for all but the first group). CS had been smoking > 10 cigarettes·day⁻¹ at least for the last three years. Assessed using an incremental running exercise test to exhaustion, the age-adjusted VO_2peak was selected as the criterion for the inclusion in the MF and LF groups, respectively. The CO-rebreathing technique was applied to assess HbM and intravascular blood volumes. A two-way ANOVA was performed to detect differences in means of hematological and endurance performance parameters. VO_2peak was found higher in MF groups (p < 0.001) but was similar between groups of similar fitness level (p = 0.57). Accordingly, peak aerobic speed was lower in CS (p < 0.001) and LF groups (p = 0.004). HbM (p = 0.013), total blood (p = 0.001) and red cell (p < 0.001) volumes were higher in CS groups. Despite the underlying expansion in HbM and total blood volume in smokers of varying fitness levels, endurance performance seems to be impaired. Future research could develop insight into the regulation of hematocrit in smokers.

吸烟涉及吸入一氧化碳（CO），这种气体与血红蛋白分子结合形成碳氧血红蛋白（COHb），从而急剧降低动脉氧含量。在本研究中，研究人员检验了定期吸烟是否会引起血红蛋白质量（HbM）的代偿性增加，并伴随训练有素的个体的血管内体积增加。30名年轻男性根据吸烟状况（CS；慢性吸烟者和NS；不吸烟者）和有氧健身水平（MF；更健康和LF；不健康）（CS-MF, CS-LF， NS-MF和NS-LF；除第一组外，其余组n=8）分为独立组。至少在过去的三年里，CS每天抽100支烟。使用增量跑步运动测试评估疲劳，选择年龄调整后的vo2峰值分别作为MF组和LF组的纳入标准。采用co -再呼吸技术评估HbM和血管内血容量。采用双向方差分析来检测血液学和耐力表现参数的差异。MF组vo2峰值升高(p

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