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Background: Birth weight, as a measure of intrauterine growth, is commonly used in epidemiological studies and is reported to be associated with adult lung function. However, findings regarding this association in previous studies have been inconsistent. Furthermore, no studies have reported associations stratified by age or smoking status, or adjusted for eosinophil count or other parameters related to type 2 airway inflammation., Methods: This cross-sectional study included 2632 men and 7237 women aged ≥20 years living in Miyagi Prefecture, Japan. Lung function was assessed based on spirometry. Birth weight data were obtained through a questionnaire survey. Analysis of covariance was used to evaluate the associations between birth weight and lung function, adjusting for potential confounders. Stratified analyses by age and smoking status were also conducted, together with a sub-analysis for low birth-weight participants., Results: Birth weight was positively associated with forced expiratory volume in 1 s (FEV 1 ) for both sexes and with vital capacity in women, after adjusting for height, age, smoking status, and parameters related to type 2 airway inflammation. The stratified analysis for smoking status revealed associations in never-smokers and ex-smokers. When stratified by age, the associations were confirmed in middle-aged participants. The effect of smoking status on the FEV 1 of low birth-weight participants was not significant., Conclusions: Our analysis of a large, Japanese adult population showed that birth weight was independently and positively associated with adult lung function, even after adjustment for age, height, smoking status, and parameters related to type 2 airway inflammation., Competing Interests: Conflict of Interest The authors have no conflicts of interest., (Copyright © 2023 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.)

Background: Although long-acting muscarinic receptor antagonists are central to the management of chronic obstructive pulmonary disease (COPD), inhaled medicines may have technical difficulty in some patients and adherence barriers., Methods: A multicenter, randomized, double-blind, placebo-controlled 3×3 crossover Phase II trial was performed to evaluate the efficacy and safety of oral administration of the antimuscarinic agent imidafenacin in patients with COPD. Twenty-seven male COPD patients with % forced expiratory volume in 1 s (FEV 1 ) ≥30% and <80% predicted were randomized to single oral dose of imidafenacin 0.1 mg, imidafenacin 0.2 mg, or placebo., Results: Maximum change in FEV 1 with both doses of imidafenacin significantly improved from baseline to 24 hrs after administration when compared with a placebo. Area under the curve in FEV 1 during 24 hrs after administration with 0.2 mg, but not 0.1 mg dose, was significantly improved when compared with a placebo, and the improvement was significantly based on dose-dependent manners. Plasma imidafenacin level was positively correlated with change in FEV 1 . All subjects with both doses of imidafenacin completed without moderate nor severe adverse events., Conclusion: A single oral dose of imidafenacin 0.1 mg or imidafenacin 0.2 mg may contribute to the improvement of pulmonary function with excellent safety and tolerability in patients with COPD., Trial Registration: JapicCTI-121760 (Japan Pharmaceutical Information Center - Clinical Trials Information [JapicCTI]; http://www.clinicaltrials.jp/user/cteSearch&#95;e.jsp)., Competing Interests: Dr. Kinoshita received honoraria from GlaxoSmithKline K.K., Daiichi Sankyo Co. Ltd., Novartis Pharma K.K., Takeda Pharmaceutical Co. Ltd., and Astellas Pharma Inc. Dr. Tsuda received honoraria from Novartis Pharma K.K., Pfizer Japan Inc., and Nippon Boehringer Ingelheim Co. Ltd. Mr. Kawashima and Dr. Suna are full-time employees of Ono Pharmaceutical Co. Ltd., Japan. Dr. Inoue received research grants from Asahi Kasei Corporation, Astellas Pharma Inc., Nippon Boehringer Ingelheim Co. Ltd., Chugai Pharmaceutical Co. Ltd., Sumitomo Dainippon Pharma Co. Ltd., Eisai Co. Ltd., MSD K.K., Nippon Kayaku Co. Ltd., Shionogi & Co. Ltd., Taisho Toyama Pharmaceutical Co. Ltd., and Teijin Pharma Ltd.; gave lectures and acted on advisory committees for Asahi Kasei Corporation, Astellas Pharma Inc., AstraZeneca K.K., Nippon Boehringer Ingelheim Co. Ltd., Chugai Pharmaceutical Co. Ltd., Eisai Co. Ltd., GlaxoSmithKline K.K., Eli Lilly Japan K.K., Kyorin Pharmaceutical Co. Ltd., MSD K.K., Meiji Seika Pharma Co. Ltd., Novartis Pharma K.K., Otsuka Pharmaceutical Co. Ltd., Pfizer Japan Inc., Shionogi & Co. Ltd., Taisho Pharmaceutical Co. Ltd., and Teijin Pharma Ltd. The authors report no other conflicts of interest in this work., (© 2019 Machida et al.)

Epithelial cell proliferation, division, and differentiation are critical for barrier repair following inflammation, but the initial trigger for this process is unknown. Here we define that sensing of apoptotic cells by the TAM receptor tyrosine kinase Axl is a critical indicator for tracheal basal cell expansion, cell cycle reentry, and symmetrical cell division. Furthermore, once the pool of tracheal basal cells has expanded, silencing of Axl is required for their differentiation. Genetic depletion of Axl triggers asymmetrical cell division, leading to epithelial differentiation and ciliated cell regeneration. This discovery has implications for conditions associated with epithelial barrier dysfunction, basal cell hyperplasia, and continued turnover of dying cells in patients with chronic inflammatory pulmonary diseases., (© 2019 Fujino et al.)

Over the past few decades, it has been clarified that the nervous system and immune system have overlapping distributions and their interactions are critical in the regulation of immunological and inflammatory responses. The cholinergic anti-inflammatory pathway, including the parasympathetic nerve systems and humoral factors orchestrate the immune responses to protect the body during infection and tissue injury. Recent investigations have attempted to clarify how the parasympathetic nerve systems attenuate the systemic inflammatory responses and identified the α7 nicotinic acetylcholine receptor (α7nAChR) as a crucial target for attenuating the release of inflammatory cytokines from inflammatory cells including macrophages and dendritic cells. This modulatory circuit pathway possibly exists in the lungs and might be involved in regulating inflammation and immunity during infection and other inflammatory lung diseases including asthma and COPD, which means that modulation of the cholinergic anti-inflammatory pathway is a possible therapeutic target for lung diseases., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Purpose: This study evaluated the efficacy of tiotropium/olodaterol vs tiotropium on lung function, exercise capacity, and physical activity in patients with COPD., Patients and Methods: A total of 184 patients aged ≥40 years with COPD (Global Initiative for Chronic Obstructive Lung Disease stage II-IV) received tiotropium/olodaterol for 6 weeks, then tiotropium for 6 weeks, or vice versa. The primary endpoint was inspiratory capacity (IC) at peak post-dose., Results: Adjusted mean IC after 6-week treatment was 1.990 L with tiotropium/olodaterol vs 1.875 L with tiotropium (difference: 115 mL; 95% CI: 77, 153; p <0.0001). Forced expiratory volume in 1 s (difference: 105 mL; 95% CI: 88, 123), forced vital capacity (difference: 163 mL; 95% CI: 130, 197), and slow vital capacity (difference: 134 mL; 95% CI: 91, 176) improved with tiotropium/olodaterol (all p <0.0001). Adjusted mean 6-min walk distance was similar between treatments in the overall population but was significantly increased with tiotropium/olodaterol in the subgroup with Global Initiative for Chronic Obstructive Lung Disease stage III/IV at baseline (difference: 18.1 m; 95% CI: 2.3, 33.9; p =0.0254). In a post hoc analysis, tiotropium/olodaterol improved the values for ≥2.0 metabolic equivalents (difference: 5.0 min; 95% CI: 0.4, 9.7; p =0.0337)., Conclusion: Tiotropium/olodaterol significantly improved IC compared with tiotropium and potentially enhanced the exercise capacity in COPD patients. A slight improvement in physical activity of relatively more than moderate intensity was also seen with tiotropium/olodaterol., Competing Interests: Disclosure TS and SN are employees of Nippon Boehringer Ingelheim. MI has received honoraria from AstraZeneca, Nippon Boehringer Ingelheim, and Novartis Pharma. YG has received honoraria from Nippon Boehringer Ingelheim, AstraZeneca, Novartis Pharma and KYORIN Pharmaceutical Co., Ltd. TM reports honoraria from Nippon Boehringer Ingelheim and Fukuda Life Tech. JU has received honoraria from Nippon Boehringer Ingelheim, Hoshi Iryo-Sanki, and Teijin Pharma. YM and KH have received honoraria from Nippon Boehringer Ingelheim. TA received compensation from Nippon Boehringer Ingelheim for statistical analysis service. The authors report no other conflicts of interest in this work.

Background: Growth differentiation factor 11 (GDF11) is reported to possess anti-aging and rejuvenating effects, including muscle regeneration and to be highly expressed in skeletal muscle. Recently, we demonstrated that the levels of plasma GDF11 were decreased in COPD. However, the effect of decreased circulating GDF11 in the pathophysiology of COPD remains unknown. The aim of this study is to investigate the association between the plasma GDF11 levels and various clinical parameters in patients with COPD., Patients and Methods: Eighteen ex-smokers as control subjects and 70 COPD patients participated in the current study. We measured the levels of plasma GDF11 using immunoblotting, lung function, physical activity using a triaxial accelerometer, quadriceps strength, exercise capacity, and systemic inflammatory markers. We investigated the association between the levels of plasma GDF11 and these clinical parameters., Results: The levels of plasma GDF11 in the COPD patients had significant positive correlations with the data of lung function. Furthermore, the levels of plasma GDF11 were significantly correlated with the physical activity, quadriceps strength, and exercise capacity. Moreover, the levels of plasma GDF11 were significantly correlated with the data of inflammatory markers. Although various factors were related to GDF11, the multiple regression analysis showed that physical activity was significantly associated with the levels of plasma GDF11., Conclusion: Physical inactivity was significantly related to the decreased GDF11 levels in COPD, which might be useful for understanding the pathogenesis of COPD. Clarifying the relationships between the physical inactivity and GDF11 may reveal a potentially attractive therapeutic approach in COPD via increasing the plasma levels of GDF11., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Background and Purpose: While the efficacy and safety of combined tiotropium and olodaterol in patients with COPD was established in a large clinical trial program, it is important to assess whether clinical data can be applied to geographic patient groups, particularly for East Asian patients who may have a different phenotypic profile to the global trial population. This study aimed to compare the lung function and safety profiles of tiotropium/olodaterol and monocomponents in East Asian and global populations from the TONADO ® trials., Materials and Methods: In the replicate, double-blind, parallel-group, active-controlled, randomized, 52-week, Phase III TONADO studies, patients received tiotropium/olodaterol, tiotropium, or olodaterol. We assessed the forced expiratory volume in 1 second (FEV 1 ) area under the curve from 0 to 3 hours (AUC 0-3 ) response and trough FEV 1 response at 24 weeks for the approved doses, tiotropium/olodaterol 5/5 μg, tiotropium 5 μg, and olodaterol 5 μg. Treatment-emergent adverse events were recorded throughout treatment and ≤21 days after study medication., Results: In the East Asian population, 1,152 patients were randomized (5,163 overall). After 24 weeks, FEV 1 AUC 0-3 and trough FEV 1 responses were greater ( P <0.0001) with tiotropium/olodaterol 5/5 μg in both populations versus tiotropium or olodaterol. The East Asian population showed slightly greater trough FEV 1 treatment differences between tiotropium/olodaterol 5/5 μg and tiotropium compared to the overall population. Generally, no increase in adverse events was seen with tiotropium/olodaterol 5/5 μg compared to tiotropium and olodaterol in either population., Conclusion: The efficacy and safety profile of tiotropium/olodaterol 5/5 μg has been demonstrated for both East Asian and global populations., Competing Interests: Disclosure RB reports grants from Boehringer Ingelheim, Novartis, and Roche, and personal fees from AstraZeneca, Boehringer Ingelheim, Chiesi, Novartis, Roche, GlaxoSmithKline, and Takeda. MI reports personal fees from Nippon Boehringer Ingelheim, AstraZeneca, Novartis Pharma KK, and Kyorin. OJ and UB are employees of Boehringer Ingelheim Pharma GmbH & Co. YZ is an employee of Boehringer Ingelheim Pharmaceuticals, Inc. The authors report no other conflicts of interest in this work.

Pulmonary alveolar proteinosis (PAP) is a severe respiratory disease characterized by dyspnea caused by accumulation of surfactant protein. Dysfunction of alveolar macrophages (AMs), which regulate the homeostasis of surfactant protein, leads to the development of PAP; for example, in mice lacking BTB and CNC homology 2 (Bach2). However, how Bach2 helps prevent PAP is unknown, and the cell-specific effects of Bach2 are undefined. Using mice lacking Bach2 in specific cell types, we found that the PAP phenotype of Bach2 -deficient mice is due to Bach2 deficiency in more than two types of immune cells. Depletion of hyperactivated T cells in Bach2 -deficient mice restored normal function of AMs and ameliorated PAP. We also found that, in Bach2 -deficient mice, hyperactivated T cells induced gene expression patterns that are specific to other tissue-resident macrophages and dendritic cells. Moreover, Bach2 -deficient AMs exhibited a reduction in cell cycle progression. IFN-γ released from T cells induced Bach2 expression in AMs, in which Bach2 then bound to regulatory regions of inflammation-associated genes in myeloid cells. Of note, in AMs, Bach2 restricted aberrant responses to excessive T cell-induced inflammation, whereas, in T cells, Bach2 puts a brake on T cell activation. Moreover, Bach2 stimulated the expression of multiple histone genes in AMs, suggesting a role of Bach2 in proper histone expression. We conclude that Bach2 is critical for the maintenance of AM identity and self-renewal in inflammatory environments. Treatments targeting T cells may offer new therapeutic strategies for managing secondary PAP., (© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.)

Background and Objective: There is increasing recognition of asthma-COPD overlap syndrome (ACOS), which shares some features of both asthma and COPD; however, the prevalence and characteristics of ACOS are not well understood. The aim of this study was to investigate the prevalence of ACOS among patients with COPD and its characteristics using a stepwise approach as stated in the recent report of the Global Initiative for Asthma (GINA) and the Global Initiative for Chronic Obstructive Lung Disease (GOLD)., Methods: This multicenter, cross-sectional, observational study enrolled outpatients who were receiving medical treatment for COPD. Clinical data, including spirometry results, were retrieved from medical records. For symptom assessment, patients were asked to complete the Clinical COPD questionnaire and the modified British Medical Research Council questionnaire., Results: Of the 1,008 patients analyzed, 167 (16.6%) had syndromic features of ACOS. Of the total number of patients, 93 and 42 (9.2% and 4.2%) also had a predefined clinical variability of ≥12%/≥200 mL and ≥12%/≥400 mL in forced expiratory volume in 1 second (FEV 1 ), respectively, and therefore were identified as having ACOS. Conversely, the number of patients who had either syndromic or spirometric feature of ACOS was 595 (59.0%, ≥12%/≥200 mL FEV 1 clinical variability), and 328 patients (32.5%, ≥12%/≥400 mL FEV 1 clinical variability) had both the features. Patients identified as having ACOS were of significantly younger age, had a shorter duration of COPD, lower number of pack-years, better lung function, milder dyspnea symptoms, and higher peripheral blood eosinophil values compared with patients with COPD alone. The rate of exacerbations in the previous year was not significantly different between the ACOS and COPD groups., Conclusion: Using a stepwise approach, as stated in the GINA/GOLD report, the proportions of patients identified as having ACOS were found to be 9.2% and 4.2% (depending on the FEV 1 variability cutoff used) among the 1,008 outpatients medically treated for COPD in a real-life clinical setting., Competing Interests: Disclosure Hiromasa Inoue has received research funding and lecture fees from AstraZeneca K.K. Satoshi Morita has received personal fees from AstraZeneca K.K. Atsushi Yoshida and Tatsunori Jinnai are employees of AstraZeneca K.K. Masakazu Ichinose has received research funding from AstraZeneca K.K. The authors report no other conflicts of interest in this work.

Background: The FLAME study demonstrated that indacaterol/glycopyrronium (IND/GLY), the fixed-dose combination of a long-acting β 2 -agonist (LABA, IND) and a long-acting muscarinic antagonist (LAMA, GLY), was superior to salmeterol/fluticasone combination (SFC) in preventing exacerbations in COPD patients with a high risk of exacerbations. In this study, we report a prespecified analysis of the efficacy and safety of IND/GLY versus SFC in Asian patients from the FLAME study., Patients and Methods: Patients from Asian centers with moderate-to-very severe COPD and ≥1 exacerbation in the previous year from the 52-week, randomized FLAME study were included. IND/GLY was compared versus SFC for effects on exacerbations, lung function (forced expiratory volume in 1 second [FEV 1 ] and forced vital capacity [FVC]), health status (St George's Respiratory Questionnaire [SGRQ]), rescue medication use, and safety., Results: A total of 510 Asian patients (IND/GLY, n=250 or SFC, n=260) were included. Compared to the overall FLAME population, the Asian cohort had more males, a shorter duration of COPD, fewer patients using inhaled corticosteroid (ICS) at screening, fewer current smokers, and more patients with very severe COPD. IND/GLY significantly reduced the rate of moderate/severe exacerbations (rate ratio: 0.75; 95% confidence interval: 0.58-0.97; P =0.027) and prolonged time to first moderate/severe exacerbation versus SFC (hazard ratio: 0.77; 95% confidence interval: 0.59-1.01; P =0.055). Predose trough FEV 1 and FVC significantly improved in Asian patients ( P <0.001). IND/GLY improved SGRQ for COPD (SGRQ-C score; P =0.006) and reduced rescue medication use ( P =0.058) at week 52. Pneumonia incidence was 3.6% with IND/GLY and 7.7% with SFC ( P =0.046)., Conclusion: In exacerbating Asian COPD patients, IND/GLY was more effective than SFC., Competing Interests: JAW has received no honoraria from industry for lectures and/or advisory boards from January 2015. Prior to January 2015 she received honoraria for lectures and/or advisory boards from Novartis, GSK, Astra Zeneca, Boehringer Ingelheim, Takeda, and Johnson and Johnson. JAW has received research grant funding in the last 3 years from Johnson and Johnson, Takeda, GSK, and Vifor Pharma. MI has served on Scientific Advisory Boards for AstraZeneca, Nippon Boehringer Ingelheim, and Novartis Pharma KK from January 2015. MI has received honoraria for speaking from AstraZeneca, GSK, Nippon Boehringer Ingelheim, Kyorin, and Novartis Pharma in 2015. NZ does not have any competing interests to declare. MH, RF, CT, FP, and DB are Novartis employees. The authors report no other conflicts of interest in this work.

Background: The efficacy and safety of once-daily tiotropium + olodaterol (T+O) maintenance treatment was demonstrated in the large, multinational, replicate, randomized, Phase III, Tonado(®) 1 (NCT01431274) and 2 (NCT01431287) studies in patients with moderate to very severe COPD. However, there may be racial differences in the effects of T+O on lung function in patients with COPD., Methods: In this Tonado(®) subgroup analysis, we assessed efficacy and safety of T+O in Japanese participants., Results: Versus the overall population, the 413 Japanese patients randomized and treated were slightly older, with more men, lower body mass index, lower baseline St George's Respiratory Questionnaire (SGRQ) scores, fewer current smokers, but with higher pack-year smoking history. A lower proportion of Japanese patients used inhaled corticosteroids, short-acting muscarinic antagonists, or short- or long-acting β-adrenergic agonists at baseline, but use of long-acting muscarinic antagonists was higher. At Week 24, mean improvements with T+O 5/5 μg in forced expiratory volume in 1 second area under the curve from 0-3 hours response were 151 mL versus olodaterol and 134 mL versus tiotropium 5 μg; mean improvements with T+O 2.5/5 μg were 87 mL versus olodaterol and 70 mL versus tiotropium 2.5 μg. Mean improvements with T+O 5/5 μg in trough forced expiratory volume in 1 second were 131 mL versus olodaterol and 108 mL versus tiotropium 5 μg; mean improvements with T+O 2.5/5 μg were 60 mL versus olodaterol and 47 mL versus tiotropium 2.5 μg. SGRQ scores improved from baseline to a greater extent with both doses of T+O versus monotherapies. Responses were similar in the overall population. Adverse-event incidence was generally balanced across treatment groups., Conclusion: Consistent with results from the overall population, T+O 5/5 μg was superior to each monotherapy for lung function and SGRQ in the Japanese sub-population of patients with COPD in Tonado(®).

Background and Aims: We used data from the Continuing to Confront COPD International Patient Survey to test the hypothesis that patients with COPD who report less engagement with their disease management are also more likely to report greater impact of the disease., Methods: This was a population-based, cross-sectional survey of 4,343 subjects aged ≥40 years from 12 countries, fulfilling a case definition of COPD based on self-reported physician diagnosis or symptomatology. The impact of COPD was measured with COPD Assessment Test, modified Medical Research Council Dyspnea Scale, and hospital admissions and emergency department visits for COPD in the prior year. The 13-item Patient Activation Measure (PAM-13) instrument and the 8-item Morisky Medication Adherence Scale (MMAS-8) were used to measure patient disease engagement and medication adherence, respectively., Results: Twenty-eight percent of subjects reported being either disengaged or struggling with their disease (low engagement: PAM-13 levels 1 and 2), and 35% reported poor adherence (MMAS-8 <6). In univariate analyses, lower PAM-13 and MMAS-8 scores were significantly associated with poorer COPD-specific health status, greater breathlessness and lower BMI (PAM-13 only), less satisfaction with their doctor's management of COPD, and more emergency department visits. In multivariate regression models, poor satisfaction with their doctor's management of COPD was significantly associated with both low PAM-13 and MMAS-8 scores; low PAM-13 scores were additionally independently associated with higher COPD Assessment Test and modified Medical Research Council scores and low BMI (underweight)., Conclusion: Poor patient engagement and medication adherence are frequent and associated with worse COPD-specific health status, higher health care utilization, and lower satisfaction with health care providers. More research will be needed to better understand what factors can be modified to improve medication adherence and patient engagement.

Background: Small airway remodeling is an important cause of the airflow limitation in chronic obstructive pulmonary disease (COPD). A large population of patients with COPD also have pulmonary hypertension. Krüppel-like factor 5 (KLF5) is a zinc-finger transcription factor that contributes to tissue remodeling in cardiovascular diseases. Here, we evaluate the possible involvement of KLF5 in the remodeling of small airways and pulmonary vessels in COPD., Methods: Lung tissues were obtained from 23 control never-smokers, 17 control ex-smokers and 24 ex-smokers with COPD. The expression of KLF5 in the lung tissues was investigated by immunohistochemistry. We investigated whether oxidative/nitrosative stress, which is a major cause of the pathogenesis in COPD, could augment the production of KLF5. We examined the role of KLF5 in the stress-mediated tissue remodeling responses. We also investigated the susceptibility of KLF5 expression to nitrosative stress using bronchial fibroblasts isolated from the lung tissues., Results: The expression of KLF5 was up-regulated in the small airways and pulmonary vessels of the COPD patients and it was mainly expressed in bronchial fibroblasts and cells of the pulmonary vessels. The extent of the KLF5 expression in the small airway of the COPD group had a significant correlation with the severity of the airflow limitation. Oxidative/nitrosative stress augmented the production of KLF5 in lung fibroblasts as well as the translocation of KLF5 into the nuclei. Silencing of KLF5 suppressed the stress-augmented differentiation into myofibroblasts, the release of collagens and metalloproteinases. Bronchial fibroblasts from the patients with COPD highly expressed KLF5 compared to those from the control subjects under basal condition and were more susceptible to the induction of KLF5 expression by nitrosative stress compared to those from the control subjects., Conclusion: We provide the first evidence that the expression of KLF5 is up-regulated in small airways and pulmonary vessels of patients with COPD and may be involved in the tissue remodeling of COPD.

Background: Olodaterol is a novel long-acting β2-agonist with proven ≥24-hour duration of action in preclinical and clinical studies., Objective: This randomized, double-blind, placebo-controlled, parallel-group study evaluated the dose response of once-daily (QD) olodaterol based on bronchodilator efficacy, safety, and pharmacokinetics over 4 weeks in Japanese patients with chronic obstructive pulmonary disease (COPD)., Methods: All eligible patients were randomized to receive 2 µg, 5 µg, or 10 µg of olodaterol or placebo for 4 weeks via the Respimat Soft Mist inhaler. The primary end point was the change from baseline in trough forced expiratory volume in 1 second (FEV1) after 4 weeks of olodaterol treatment. Secondary end points included trough FEV1 after 1 week and 2 weeks of treatment, FEV1 area under the curve from 0 hour to 3 hours (AUC(0-3)), peak FEV1 from 0 hour to 3 hours (peak FEV1), and corresponding forced vital capacity (FVC) responses. Rescue medication use, COPD symptoms, physician global evaluation, pharmacokinetics, and safety were also assessed., Results: A total of 328 patients with COPD were randomized to receive treatment. All olodaterol doses assessed in the study showed statistically significant increases in trough FEV1 compared to placebo at Day 29 (P<0.0001). Mean increases in peak FEV1 and FEV1 AUC(0-3) compared to placebo were also significant (P<0.0001). A clear dose-response relationship was observed across all treatment groups. FVC responses (trough and FVC AUC(0-3)) supported FEV1 outcomes. All doses of olodaterol were well tolerated, and no safety concerns were identified., Conclusion: QD olodaterol demonstrated 24-hour bronchodilator efficacy and was well tolerated in Japanese patients with COPD., Trial Registration: ClinicalTrials.gov: NCT00824382.

Background: Improvement in the daily physical activity (PA) is important for the management of chronic obstructive pulmonary disease (COPD). However, the effects of pharmacologic treatment on PA are not well understood. We evaluated the effects of additional medications, including bronchodilator with or without inhaled corticosteroid, based on airflow limitation and breathlessness on the PA in COPD patients and the factors that could predict or affect the improvement in PA., Methods: A prospective non-randomized observational study was employed. Twenty-one COPD subjects without any other diseases that might reduce PA were recruited. The PA was measured with a triaxial accelerometer for 2 weeks, and pulmonary function tests and incremental shuttle walking tests were administered before and after 4-week treatment with an additional medication., Results: Bronchodilation was obtained by additional medication. The mean values of PA evaluated by metabolic equivalents (METs) at ≥3.0 METs and the duration of PA at ≥3.0 METs and ≥3.5 METs were improved by medication. The % change in the duration of PA at ≥3.5 METs was significantly correlated with the baseline functional residual capacity (FRC), residual volume, and inspiratory capacity/total lung capacity. However, the % change in the duration of PA at any intensity was not correlated with the % changes of any values of the pulmonary function tests or incremental shuttle walking test except the PA at ≥2.5 METs with FRC., Conclusion: Medication could improve the PA in patients with COPD, especially at a relatively high intensity of activity when medication was administered based on airflow limitation and breathlessness. The improvement was seen in the patients with better baseline lung volume, but was not correlated with the improvements in the pulmonary function tests or exercise capacity.

Chronic inflammation induces lymphangiogenesis and blood vessel remodelling. Since aged pneumonia patients often have repeated episodes of aspiration pneumonia, the pathogenesis may involve chronic inflammation. For lymphangiogenesis, VEGFR-3 and its ligand VEGF-C are key factors. No previous studies have examined chronic inflammation or vascular changes in aspiration pneumonia or its mouse models. In lung inflammation, little is known about the effect of blocking VEGFR-3 on lung lymphangiogenesis and, moreover, its effect on the disease condition. This study aimed to establish a mouse model of aspiration pneumonia, examine the presence of chronic inflammation and vascular changes in the model and in patients, and evaluate the effect of inhibiting VEGFR-3 on the lymphangiogenesis and disease condition in this model. To induce aspiration pneumonia, we repeated inoculation of pepsin at low pH and LPS into mice for 21-28 days, durations in which bronchioalveolar lavage and plasma leakage in the lung suggested the presence of exaggerated inflammation. Conventional and immunohistochemical analysis of tracheal whole mounts suggested the presence of chronic inflammation, lymphangiogenesis, and blood vessel remodelling in the model. Quantitative RT-PCR of the trachea and lung suggested the involvement of lymphangiogenic factor VEGF-C, VEGFR-3, and pro-inflammatory cytokines. In the lung, the aspiration model showed the presence of chronic inflammation and exaggerated lymphangiogenesis. Treatment with the VEGFR inhibitor axitinib or the VEGFR-3 specific inhibitor SAR131675 impaired lymphangiogenesis in the lung and improved oxygen saturation in the aspiration model. Since the lung is the main site of aspiration pneumonia, the changes were intensive in the lung and mild in the trachea. Human lung samples also showed the presence of chronic inflammation and exaggerated lymphangiogenesis, suggesting the relevance of the model to the disease. These results suggest lymphatics in the lung as a new target of analysis and therapy in aspiration pneumonia., (Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Viral infection often triggers asthma exacerbation and contributes to airway remodeling. Cell signaling in viral infection is mainly mediated through TLR3. Many mediators are involved in airway remodeling, but matrix metalloproteinases (MMPs) are key players in this process in asthma. However, the role of TLR3 activation in production of MMPs is unknown. In this study, we examined the effects of polyinosinic-polycytidylic acid [poly(I:C)], a ligand for TLR3, on production of MMPs in human lung fibroblasts, with a focus on nitrosative stress in TLR3 modulation of MMP production. After lung fibroblasts were treated with poly(I:C), production of MMP-1, -2, and -9 and inducible NO synthase (iNOS) was assessed. The roles of NF-κB and IFN regulatory factor-3 (IRF-3) in the poly(I:C)-mediated production of MMPs and the responsiveness to poly(I:C) of normal lung fibroblasts and asthmatic lung fibroblasts were also investigated. Poly(I:C) augmented production of MMPs and iNOS in fibroblasts, and an iNOS inhibitor diminished this production of MMPs. Poly(I:C) stimulated translocation of NF-κB and IRF-3 into the nucleus in fibroblasts and inhibition of NF-κB or IRF-3 abrogated the poly(I:C)-induced increase in both iNOS expression and release of MMPs. Poly(I:C)-induced production of iNOS and MMPs was greater in asthmatic fibroblasts than in normal fibroblasts. We conclude that viral infection may induce nitrosative stress and subsequent MMP production via NF-κB- and IRF-3-dependent pathways, thus potentiating viral-induced airway remodeling in asthmatic airways., (Copyright © 2014 by The American Association of Immunologists, Inc.)

Background: The excess and persistent accumulation of fibroblasts due to aberrant tissue repair results in fibrotic diseases such as idiopathic pulmonary fibrosis. Recent reports have revealed significant changes in microRNAs during idiopathic pulmonary fibrosis and evidence in support of a role for microRNAs in myofibroblast differentiation and the epithelial-mesenchymal transition in the context of fibrosis. It has been reported that microRNA-21 is up-regulated in myofibroblasts during fibrosis and promotes transforming growth factor-beta signaling by inhibiting Smad7. However, expression changes in microRNA-21 and the role of microRNA-21 in epithelial-mesenchymal transition during lung fibrosis have not yet been defined., Methods: Lungs from saline- or bleomycin-treated C57BL/6 J mice and lung specimens from patients with idiopathic pulmonary fibrosis were analyzed. Enzymatic digestions were performed to isolate single lung cells. Lung epithelial cells were isolated by flow cytometric cell sorting. The expression of microRNA-21 was analyzed using both quantitative PCR and in situ hybridization. To induce epithelial-mesenchymal transition in culture, isolated mouse lung alveolar type II cells were cultured on fibronectin-coated chamber slides in the presence of transforming growth factor-β, thus generating conditions that enhance epithelial-mesenchymal transition. To investigate the role of microRNA-21 in epithelial-mesenchymal transition, we transfected cells with a microRNA-21 inhibitor. Total RNA was isolated from the freshly isolated and cultured cells. MicroRNA-21, as well as mRNAs of genes that are markers of alveolar epithelial or mesenchymal cell differentiation, were quantified using quantitative PCR., Results: The lung epithelial cells isolated from the bleomycin-induced lung fibrosis model system had decreased expression of epithelial marker genes, whereas the expression of mesenchymal marker genes was increased. MicroRNA-21 was significantly upregulated in isolated lung epithelial cells during bleomycin-induced lung fibrosis and human idiopathic pulmonary fibrosis. MicroRNA-21 was also upregulated in the cultured alveolar epithelial cells under the conditions that enhance epithelial-mesenchymal transition. Exogenous administration of a microRNA-21 inhibitor prevented the increased expression of vimentin and alpha-smooth muscle actin in cultured primary mouse alveolar type II cells under culture conditions that induce epithelial-mesenchymal transition., Conclusions: Our experiments demonstrate that microRNA-21 is increased in lung epithelial cells during lung fibrosis and that it promotes epithelial-mesenchymal transition.

Abnormal structural alterations termed remodeling, including fibrosis and alveolar wall destruction, are important features of the pathophysiology of chronic airway diseases such as chronic obstructive pulmonary disease (COPD) and asthma. 25-hydroxycholesterol (25-HC) is enzymatically produced by cholesterol 25-hydorxylase (CH25H) in macrophages and is reported to be involved in the formation of arteriosclerosis. We previously demonstrated that the expression of CH25H and production of 25HC were increased in the lungs of COPD. However, the role of 25-HC in lung tissue remodeling is unknown. In this study, we investigated the effect of 25-HC on fibroblast-mediated tissue remodeling using human fetal lung fibroblasts (HFL-1) in vitro. 25-HC significantly augmented α-smooth muscle actin (SMA) (P<0.001) and collagen I (P<0.001) expression in HFL-1. 25-HC also significantly enhanced the release and activation of matrix metallaoproteinase (MMP)-2 (P<0.001) and MMP-9 (P<0.001) without any significant effect on the production of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. 25-HC stimulated transforming growth factor (TGF)-β1 production (P<0.01) and a neutralizing anti-TGF-β antibody restored these 25-HC-augmented pro-fibrotic responses. 25-HC significantly promoted the translocation of nuclear factor (NF)-κB p65 into the nuclei (P<0.01), but not phospholylated-c-jun, a complex of activator protein-1. Pharmacological inhibition of NF-κB restored the 25-HC-augmented pro-fibrotic responses and TGF-β1 release. These results suggest that 25-HC could contribute to fibroblast-mediated lung tissue remodeling by promoting myofibroblast differentiation and the excessive release of extracellular matrix protein and MMPs via an NF-κB-TGF-β dependent pathway., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Small cell lung cancer (SCLC) is a subtype of lung cancer with poor prognosis. Expression array analysis of 23 SCLC cases and 42 normal tissues revealed that EZH2 and other PRC2 members were highly expressed in SCLC. ChIP-seq for H3K27me3 suggested that genes with H3K27me3(+) in SCLC were extended not only to PRC2-target genes in ES cells but also to other target genes such as cellular adhesion-related genes. These H3K27me3(+) genes in SCLC were repressed significantly, and introduction of the most repressed gene JUB into SCLC cell line lead to growth inhibition. Shorter overall survival of clinical SCLC cases correlated to repression of JUB alone, or a set of four genes including H3K27me3(+) genes. Treatment with EZH2 inhibitors, DZNep and GSK126, resulted in growth repression of SCLC cell lines. High PRC2 expression was suggested to contribute to gene repression in SCLC, and may play a role in genesis of SCLC.

The anti-inflammatory effects of theophylline have been reported to include inhibition of the release of proinflammatory mediators from macrophages and neutrophils. Overproduction of reactive nitrogen species (RNS) has been reported in the airways of patients with chronic obstructive pulmonary disease (COPD), and this causes tissue inflammation and injury. We investigated whether peroxynitrite stimulated the release of matrix metalloproteinases 2 and 9 (MMP-2 and -9; gelatinases) from human fetal lung fibroblasts (HFL-1 cell line) and whether theophylline inhibited the peroxynitrite-augmented release of MMPs. HFL-1 cells and primary lung fibroblasts were treated with peroxynitrite (an RNS), and gelatinases levels were evaluated by gelatin zymography. The inhibitory effect of theophylline on the peroxynitrite-augmented release of MMP-2 and MMP-9 was also investigated. To explore the cell signaling pathways involved in the peroxynitrite-induced gelatinases release and the inhibitory effect of theophylline, transforming growth factor-β(1) (TGF-β(1)), nuclear factor-κB (NF-κB), and histone deacetylase (HDAC) were measured. Peroxynitrite significantly augmented the release of MMP-2 and MMP-9 by fibroblasts (P < 0.01), as well as TGF-β(1) release (P < 0.01), NF-κB activation (P < 0.01), and HDAC2 inactivation (P < 0.01). An NF-κB inhibitor diminished the RNS-augmented release of MMPs and TGF-β(1) (P < 0.01), and a neutralizing TGF-β antibody also diminished MMP release (P < 0.01). Theophylline significantly inhibited the peroxynitrite-augmented release of MMP-2 and MMP-9 in HFL-1 cells and normal adult lung fibroblasts, and it also inhibited the peroxynitrite-mediated HDAC2 inactivation, NF-κB activation, and TGF-β(1) release in HFL-1 cells (all P < 0.01). These results suggest that peroxynitrite can influence tissue remodeling by promoting gelatinases release, while theophylline suppresses peroxynitrite-induced tissue remodeling via pathways involving NF-κB/TGF-β(1) and/or HDAC in the HFL-1 cell line.

Background and Objective: 25-Hydroxycholesterol (25-HC) is produced from cholesterol by the enzyme cholesterol 25-hydroxylase and is associated with atherosclerosis of vessels. Recently, 25-HC was reported to cause inflammation in various types of tissues. The aim of this study was to assess the production of 25-HC in the airways and to elucidate the role of 25-HC in neutrophil infiltration in the airways of patients with chronic obstructive pulmonary disease (COPD)., Methods: Eleven control never-smokers, six control ex-smokers without COPD and 13 COPD patients participated in the lung tissue study. The expression of cholesterol 25-hydroxylase in the lung was investigated. Twelve control subjects and 17 patients with COPD also participated in the sputum study. The concentrations of 25-HC in sputum were quantified by liquid chromatography/mass spectrometry/mass spectrometry analysis. To elucidate the role of 25-HC in neutrophilic inflammation of the airways, the correlation between 25-HC levels and neutrophil counts in sputum was investigated., Results: The expression of cholesterol 25-hydroxylase was significantly enhanced in lung tissue from COPD patients compared with that from control subjects. Cholesterol 25-hydroxylase was localized in alveolar macrophages and pneumocytes of COPD patients. The concentration of 25-HC in sputum was significantly increased in COPD patients and was inversely correlated with percent of predicted forced vital capacity, forced expiratory volume in 1 s and diffusing capacity of carbon monoxide. The concentrations of 25-HC in sputum were significantly correlated with sputum interleukin-8 levels and neutrophil counts., Conclusions: 25-HC production was enhanced in the airways of COPD patients and may play a role in neutrophilic inflammation., (© 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.)

We performed a pilot investigation of the cardiopulmonary baroreflex control of ventricular contractility in two conscious dogs. We specifically measured spontaneous beat-to-beat hemodynamic variability before and after the administration of propranolol. We then identified the transfer function relating beat-to-beat fluctuations in central venous pressure (CVP) to maximal ventricular elastance (E(max)) to characterize the cardiopulmonary baroreflex control of ventricular contractility, while accounting for the influences of arterial blood pressure fluctuations on E(max) via the arterial baroreflex and heart rate fluctuations on E(max) via the force-frequency relation. Our major finding is that the cardiopulmonary baroreflex responds to an increase (decrease) in CVP by increasing (decreasing) E(max) via the beta-sympathetic nervous system.

Irreversible airflow limitation in asthma is associated with airway remodeling in which the differentiation of fibroblasts to myofibroblasts plays a pivotal role. In asthmatic airways, excessive production of reactive nitrogen species (RNS) has been observed. The aim of this study is to evaluate whether peroxynitrite, one of the RNS, can affect the differentiation of fibroblasts to myofibroblasts. Human fetal lung fibroblasts were treated with various concentrations of authentic peroxynitrite or a peroxynitrite donor 3-morpholinosydnonimine hydrochloride (SIN-1), and the expressions of alpha-smooth muscle actin (alpha-SMA) and desmin, markers of myofibroblast differentiation, were evaluated. The releases of transforming growth factor-beta(1) (TGF-beta(1)) and ECM proteins including fibronectin and collagen I were assessed. To clarify the mechanism in this differentiation, the effect of anti-TGF-beta antibody or NF-kappaB inhibitors on the alpha-SMA expression and ECM production was assessed. Peroxynitrite and SIN-1 significantly augmented the alpha-SMA expression compared with control in a concentration-dependent manner (P < 0.01 and P < 0.05, respectively). Peroxynitrite significantly increased desmin and TGF-beta(1) production (P < 0.01). Peroxynitrite enhanced the translocation of NF-kappaB into the nucleus confirmed by immunocytostaining and immunoblotting. Peroxynitrite-augmented alpha-SMA expression was blocked by NF-kappaB inhibitors, MG132 and caffeic acid phenethyl ester (CAPE), and anti-TGF-beta antibody. CAPE completely inhibited the peroxynitrite-augmented TGF-beta(1) release. The production of fibronectin and collagen I was significantly increased by peroxynitrite (P < 0.01) and inhibited by anti-TGF-beta antibody. These results suggest that RNS can affect the differentiation to myofibroblasts and excessive ECM production via a NF-kappaB-TGF-beta(1)-dependent pathway.

The involvement of inflammation in the pathogenesis of chronic obstructive pulmonary disease (COPD) has been investigated using samples from relatively central airways such as airway biopsies, but there have been fewer studies in the peripheral lung, which is thought to be the main site of the disease process. To determine the molecules that relate to the mechanisms underlying the pathogenesis of COPD, we evaluated the mRNA expression of inflammatory cytokines, chemokines, oxidant enzymes, antioxidant enzymes, proteinases and antiproteinases in peripheral lung tissues from 33 COPD and non-COPD subjects who were undergoing lung resection for lung cancer using an RT-PCR technique. Among the 42 studied candidate genes, the expressions of mRNA for catalase, glutathion S-transferase P1 (GSTP1), glutathion S-transferase M1 (GSTM1), microsomal epoxide hydrolase (mEPHX) and tissue inhibitor of metalloproteinase 2 (TIMP2) were significantly decreased in COPD lung tissues compared with those in non-COPD tissues, and most of these decreases were significantly correlated with the degree of airflow limitation. On the other hand, the expressions of mRNA for interleukin 1beta (IL-1beta), interleukin 8 (IL-8), growth-related oncogene-alpha (Gro-alpha) and monocyte chemotactic protein-1 (MCP-1) were significantly increased in COPD lungs. Most of these changes were also associated with cigarette smoking. These data suggest that an impairment of protective mechanisms against oxidants and xenobiotics, in addition to the upregulation of CXC- and CC-chemokines, may be associated with cigarette smoking and involved in the inflammatory process of COPD.

This study examines the role of endogenous nitric oxide (NO) in airway microvascular leakage induced inflammatory mediators, which play an important role in asthmatic airways. Guinea-pigs were anesthetized and mechanically-ventilated with monitoring of arterial blood pressure, and airway microvascular leakage induced by intravenous injection of substance P (SP), leukotriene D4 (LTD4) and histamine was evaluated using Evans blue dye and Monastral blue dye in the presence and absence of the NO synthase inhibitors, L-NG-nitroarginine methyl ester (L-NAME) and L-NG-monomethyl arginine (L-NMMA). The effect of a soluble guanylate cyclase inhibitor, LY83583, on SP-induced dye leakage was also examined. Intravenous injection of SP (1 microgram.kg-1), LTD4 (1 microgram.kg-1) and histamine (100 micrograms.kg-1) significantly increased dye extravasation at all airway levels. Pretreatment with L-NAME (10 mg.kg-1 i.v.) and L-NMMA (100 mg.kg-1 i.v.) significantly inhibited SP-induced extravasation, and L-arginine (100 mg.kg-1 i.v.) reversed L-NAME-induced inhibition. L-NAME (10 mg.kg-1 i.v.) also significantly inhibited LTD4-induced dye extravasation only in central airways, and this inhibitory effect was abolished by a neurokinin-1 (NK1) antagonist, FK888 (10 mg.kg-1 i.v.) pretreatment. Histamine-induced dye extravasation was not affected by L-NAME. LY83583 (2.5 and 7.5 mg.kg-1 i.v.) partially but significantly reduced SP-induced dye leakage. These results suggest that endogenous nitric oxide plays a role in neurokinin-1 receptor-mediated airway microvascular leakage, and presumably involves the guanylate cyclase pathway.

To examine the role of endogenous nitric oxide in allergic airway inflammation, we investigated the effect of a nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (l-NAME), on antigen-induced airway microvascular leakage in actively sensitized guinea pigs by using Evans blue dye. Three weeks after sensitization with ovalbumin (10 micrograms), the tracheas were cannulated, and lungs were artificially ventilated. Animals were pretreated with atropine and propranolol (both 1 mg/kg, intravenously) to avoid neural modification. Ovalbumin inhalation (3 mg/ml, 1 minute) challenge caused significant microvascular leakage in all airways portions, which was significantly suppressed in a dose-dependent manner by pretreatment with intravenous injection of L-NAME (1 and 10 mg/kg) but not with the inactive enantiomer D-NAME (10 mg/kg). This inhibition by L-NAME was significantly reversed by co-administration of L-arginine (100 mg/kg, intravenously). Pretreatment with a vasoconstrictor, phenylephrine (20 micrograms/kg, intravenously), had no inhibitory effects on antigen-induced airway microvascular leakage despite increasing systemic blood pressure. Inhalation of representative mast cell-derived mediators, histamine (2 mg/ml, 1 minute) or leukotriene D4 (5 micrograms/ml, 1 minute), produced significant microvascular leakage in all airways. L-NAME (10 mg/kg, intravenously) partially but significantly inhibited leukotriene D4-induced leakage, whereas histamine-induced leakage was not affected. These results suggest that endogenous nitric oxide acts to increase airway microvascular leakage after airway allergic reaction.

We examined the effect of ibudilast, an antiasthma drug, on neurogenic microvascular leakage in guinea-pig airways by measuring extravasation of Evans blue dye. After intravenous pretreatment with atropine (1 mg/kg) and propranolol (1 mg/kg), bilateral vagal stimulation significantly increased nonadrenergic noncholinergic (NANC)-mediated leakage of dye in the trachea (Tr), the main bronchi (MB), and the central (cIPA) and peripheral (pIPA) intrapulmonary airways. Ibudilast (1.0 to 100 micrograms/kg given intravenously) did not affect basal leakage, but it significantly inhibited NANC-mediated plasma extravasation in a dose-dependent manner, with a maximal inhibition of 74.0% (Tr, p < 0.05), 89.1% (MB, p < 0.05), 91.4% (cIPA, p < 0.01), and 84.3% (pIPA, p < 0.05) at 100 micrograms/kg. Plasma extravasation induced by exogenous substance P (1 microgram/kg given intravenously) was not inhibited by ibudilast. Glibenclamide, an inhibitor of ATP-sensitive potassium channels, blocked the inhibitory effect of ibudilast. We conclude that ibudilast inhibits neurogenic leakage by prejunctional inhibition of neuropeptide release from airway sensory nerve terminals via an ATP-sensitive potassium channel.

We studied pulmonary functions in 17 female patients with mixed connective tissue disease (MCTD) to detect early pulmonary involvement in this disease; in 8 of the 17 patients follow-up studies were also performed at 1.2- to 5.9-year intervals. In the first pulmonary function tests, decreases in vital capacity (VC) and diffusing capacity (DLCO) were observed in 6 (35%) and 8 (47%) patients, respectively. The ratio of forced expiratory volume in one second to VC was normal in all the patients, but pulmonary resistance and static compliance were abnormal in 6 (35%) and 10 (59%) patients, respectively. However, frequency dependence of dynamic compliance was found in all 16 patients tested. Moreover, 4 (24%) of the 17 patients had normal DLCO and DLCO-to-alveolar volume ratio (DLCO/VA). Reductions in DLCO and DLCO/VA were significantly correlated with the disease duration. These results suggest that small airway obstruction is an early and frequent indication of functional pulmonary impairment, and that impairment of alveolar gas exchange is progressive in patients with MCTD.

We studied the role of histamine H3-receptors on neurogenic microvascular leakage in guinea pig airways by measuring extravasation of Evans blue dye. In guinea pig airways the major component of the neurogenic leakage is nonadrenergic noncholinergic (NANC) mediated, due to release of tachykinins. Anesthetized guinea pigs were pretreated with propranolol and atropine to block the beta-adrenergic and cholinergic responses and with mepyramine and cimetidine to block histamine H1- and H2-receptors, respectively. Vagal stimulation significantly increased leakage of dye in trachea (Tr), main bronchi (MB), and central (cIPA) and peripheral intrapulmonary airways (pIPA). The selective H3-receptor agonist (R)-alpha-methylhistamine (alpha-MeHA, 0.3-3 mg/kg iv) did not alter basal leakage but inhibited NANC-mediated leakage in a dose-dependent manner with a maximal inhibition of 56.9 (Tr, P less than 0.01), 66.7 (MB, P less than 0.01), 67.5 (cIPA, P less than 0.01), and 58.2% (pIPA, P less than 0.05) at 1 mg/kg. Pretreatment with phentolamine (2.5 mg/kg iv) had no effect on the inhibitory response produced by alpha-MeHA, but the H3-receptor antagonist thioperamide (5 mg/kg ip) blocked its effect. Exogenous substance P (1 microgram/kg iv) caused comparable plasma leakage to NANC-mediated response but was not inhibited by alpha-MeHA. We conclude that H3-agonists inhibit neurogenic leakage by prejunctional inhibition of neuropeptide release from airway sensory nerves.

To determine the sensory receptor of the nonadrenergic inhibitory nervous system (NAIS), 22 cats were anesthetized and serotonin was continuously administered (50-250 micrograms.kg-1.min-1 iv) to increase pulmonary resistance (RL) to 377 +/- 57% (SE) of the control value. We then 1) mechanically irritated the trachea, 2) intravenously administered capsaicin (5 micrograms/kg), or 3) induced hypoxia (arterial PO2 30-40 Torr) to stimulate irritant and bronchial C-fiber receptors, pulmonary C-fiber receptors, or the carotid body (chemoreceptors), respectively. After treatment with atropine (3 mg/kg iv) and propranolol (2 mg/kg iv), the serotonin-induced change in RL was reduced by 58.6 +/- 14.3% by mechanical irritation and 63.3 +/- 12.1% by intravenous capsaicin. However, hypoxia produced no dilatation of the airways. In further experiments, we employed capsaicin inhalation to stimulate bronchial C-fiber receptors. Inhaled capsaicin (0.1%, for 5 breaths) also reduced RL by 79.2 +/- 9.2% of the elevated value, after atropine and propranolol. Treatment with a ganglionic blocking agent, hexamethonium (2 mg/kg iv), abolished bronchodilator responses, implying that a reflex pathway through vagal nerves is involved in this phenomenon. These results suggest that pulmonary and bronchial C-fiber receptors may be involved as sensory receptors in NAIS reflex bronchodilatation.

The sensory receptors and reflex pathways of the nonadrenergic inhibitory nervous system (NAINS) were examined, using separately ventilated left and right lungs in cats. During bronchoconstriction induced by 5-hydroxytryptamine (5-HT) (50 to 250 micrograms/kg/min, i.v.) infusion after atropine (3 mg/kg, i.v.) and propranolol (2 mg/kg, i.v.), one lung was challenged with (1) citric acid aerosol or (2) capsaicin aerosol or (3) lung volume change (lung inflation). Citric acid or capsaicin inhalation to one lung produced significant bronchodilatation in not only the stimulated lung (SL) but also in the opposite lung (OL). The 5-HT-induced change in pulmonary resistance (RL) was reduced 66.5 +/- 3.3% (mean +/- 1 SE) (SL) and 53.0 +/- 8.1% (OL) by citric acid (20%) and 40.5 +/- 8.9% (SL) and 44.0 +/- 9.9% (OL) by capsaicin (0.1%) inhalation, respectively. These bronchodilatations were abolished by bilateral vagotomy. Inflation of one side of the lung did not reduce the 5-HT-induced change in RL in the OL. These findings indicate that (1) C-fiber and irritant receptors are the possible sensory receptors of the NAINS reflex pathway, and (2) afferent nerve stimulation of NAINS in one lung can produce reflex bronchodilatation in both lungs.