leukotriene-d4 and Asthma

Asthma is a chronic inflammatory and allergic disease that is mainly characterized by reversible airway obstruction and bronchial hyperresponsiveness. The incidence of asthma is increasing with more than 350 million people worldwide are affected. Up to now, there is no therapeutic option for asthma and most of the prescribed drugs aim to ameliorate the symptoms of the disease especially during the acute exacerbations after trigger exposure. Asthma is a heterogonous disease that involves interactions between inflammatory mediators and cellular components within the disease microenvironment including inflammatory and structural cells. Cysteinyl leukotrienes (cys-LTs) are inflammatory lipid mediators that have potent roles in asthma pathogenesis. CysLTs consisting of LTC

Topics: Acetates; Airway Remodeling; Animals; Anti-Asthmatic Agents; Asthma; Bronchial Hyperreactivity; Cyclopropanes; Cysteine; Gene Expression; Humans; Hypersensitivity; Indoles; Inflammation Mediators; Leukotriene Antagonists; Leukotriene D4; Leukotrienes; Phenylcarbamates; Quinolines; Receptors, Leukotriene; Sulfides; Sulfonamides; Tosyl Compounds

This mini-review is focused on the enzyme 15-lipoxygenase-1 (15-LO-1) and eoxins in airway inflammatory diseases and Hodgkin lymphoma. Several studies have demonstrated increased expression and activity of 15-LO-1 in the respiratory tissue from asthma patients , indicating a pathophysiological role of this enzyme in airway inflammation. Eoxins were recently identified as pro-inflammatory metabolites of arachidonic acid, formed through the 15-LO-1 pathway, in human eosinophils, mast cells, airway epithelial cells and Hodgkin lymphoma. Mice deficient of 12/15-LO, the ortholog to human 15-LO-1, had an attenuated allergic airway inflammation compared to wild type controls, also indicating a pathophysiological role of this enzyme in respiratory inflammation. The putative therapeutic implications of 15-LO-1 inhibitors in the treatment of asthma, chronic obstructive pulmonary disorder and Hodgkin lymphoma are discussed.

Topics: Animals; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Asthma; Eosinophils; Hodgkin Disease; Humans; Inflammation; Leukotriene D4; Leukotrienes; Lung; Mice; Organ Specificity; Pulmonary Disease, Chronic Obstructive; Reed-Sternberg Cells

Leukotriene (LT) E(4) mediates many of the principal features of bronchial asthma, such as bronchial constriction, hyperresponsiveness, eosinophilia, and increased vascular permeability. Furthermore, it is the most stable of the cysteinyl leukotrienes (CysLTs) and can be active at the site of release for a prolonged time after its synthesis. There might be several reasons why LTE(4) has been forgotten. LTE(4) demonstrated low affinity for CysLT(1) and CysLT(2) receptors in equilibrium competition assays. It was less potent than other CysLTs in functional assays, such as calcium flux, in cells transfected with CysLT(1) and CysLT(2). The introduction of CysLT(1) antagonists into clinical practice diverted interest into CysLT(1)-related mechanisms, which were mediated mainly by LTD(4). However, experiments with animal models and human studies have revealed that LTE(4) has unique characteristics that cannot be explained by the current knowledge of CysLT(1) and CysLT(2). These activities include its potency relative to other CysLTs to increase airway responsiveness to histamine, to enhance eosinophilic recruitment, and to increase vascular permeability. Asthmatic airways also demonstrate marked in vivo relative hyperresponsiveness to LTE(4), especially in patients with aspirin-sensitive respiratory disease. This has stimulated a search for additional LT receptors that would respond preferentially to LTE(4) stimulation.

Topics: Animals; Aspirin; Asthma; Bronchial Hyperreactivity; Drug Hypersensitivity; Histamine; Humans; Leukotriene C4; Leukotriene D4; Leukotriene E4; Methacholine Chloride; Receptors, Leukotriene; Skin

The intracellular parent of the cysteinyl leukotrienes (cysLTs), leukotriene (LT) C(4), is formed by conjugation of LTA(4) and reduced glutathione by LTC(4) synthase in mast cells, eosinophils, basophils, and macrophages. After extracellular export, LTC(4) is converted to LTD(4) and LTE(4) through sequential enzymatic removal of glutamic acid and then glycine. Only LTE(4) is sufficiently stable to be prominent in biologic fluids, such as urine or bronchoalveolar lavage fluid, of asthmatic individuals and at sites of inflammation in animal models. LTE(4) has received little attention because it binds poorly to the classical type 1 and 2 cysLT receptors and is much less active on normal airways than LTC(4) or LTD(4). However, early studies indicated that LTE(4) caused skin swelling in human subjects as potently as LTC(4) and LTD(4), that airways of asthmatic subjects (particularly those that were aspirin sensitive) were selectively hyperresponsive to LTE(4), and that a potential distinct LTE(4) receptor was present in guinea pig trachea. Recent studies have begun to uncover receptors selective for LTE(4): P2Y(12), an adenosine diphosphate receptor, and CysLT(E)R, which was observed functionally in the skin of mice lacking the type 1 and 2 cysLT receptors. These findings prompt a renewed focus on LTE(4) receptors as therapeutic targets that are not currently addressed by available receptor antagonists.

Topics: Animals; Asthma; Guinea Pigs; Humans; Leukotriene Antagonists; Leukotriene C4; Leukotriene D4; Leukotriene E4; Mice; Receptors, Leukotriene; Receptors, Purinergic P2; Skin

Cysteinyl-leukotrienes (cysteinyl-LTs), that is, LTC4, LTD4, and LTE4, trigger contractile and inflammatory responses through the specific interaction with G protein-coupled receptors (GPCRs) belonging to the purine receptor cluster of the rhodopsin family, and identified as CysLT receptors (CysLTRs). Cysteinyl-LTs have a clear role in pathophysiological conditions such as asthma and allergic rhinitis (AR), and have been implicated in other inflammatory conditions including cardiovascular diseases, cancer, atopic dermatitis, and urticaria. Molecular cloning of human CysLT1R and CysLT2R subtypes has confirmed most of the previous pharmacological characterization and identified distinct expression patterns only partially overlapping. Interestingly, recent data provide evidence for the immunomodulation of CysLTR expression, the existence of additional receptor subtypes, and of an intracellular pool of CysLTRs that may have roles different from those of plasma membrane receptors. Furthermore, genetic variants have been identified for the CysLTRs that may interact to confer risk for atopy. Finally, a crosstalk between the cysteinyl-LT and the purine systems is being delineated. This review will summarize and attempt to integrate recent data derived from studies on the molecular pharmacology and pharmacogenetics of CysLTRs, and will consider the therapeutic opportunities arising from the new roles suggested for cysteinyl-LTs and their receptors.

Topics: Adult; Animals; Asthma; Cardiovascular Diseases; Child; Child, Preschool; Dermatitis, Atopic; Female; Humans; Hydroxyurea; Leukotriene Antagonists; Leukotriene C4; Leukotriene D4; Leukotriene E4; Membrane Proteins; Pharmacogenetics; Receptors, Leukotriene; Receptors, Purinergic; Recombinant Proteins; Rhinitis, Allergic, Seasonal; SRS-A; Tissue Distribution

Twenty five years after the structure elucidation of slow reacting substance of anaphylaxis, antileukotrienes are established as a new therapeutic modality in asthma. The chapter reviews the biochemistry and pharmacology of leukotrienes and antileukotrienes with particular focus on the different usage of antileukotrienes for treatment of asthma and rhinitis in Europe and the US. Further research needs and new areas for leukotriene involvement in respiratory diseases are also discussed.

Topics: Acetates; Animals; Asthma; Clinical Trials as Topic; Cyclopropanes; Humans; Hydroxyurea; Leukotriene Antagonists; Leukotriene C4; Leukotriene D4; Leukotriene E4; Lipoxygenase Inhibitors; Membrane Proteins; Quinolines; Receptors, Leukotriene; Respiratory System; Rhinitis; Sulfides

Initiation and regulation of allergic inflammation is influenced by many factors, including cell type, membrane receptors, and mediators generated. Furthermore, the altered response of targeted tissues (ie, airway smooth muscle) becomes important to the eventual expression of asthma. Finally, the genetic regulation and association of genetic polymorphisms has enhanced our understanding of host susceptibility. In this review key findings published in 2004 issues of the Journal of Allergy and Clinical Immunology are highlighted to demonstrate recent advances in these areas.

Topics: Animals; Asthma; Basophils; Disease Models, Animal; Eosinophils; Genetic Predisposition to Disease; Humans; Inflammation; Leukotriene D4; Mast Cells; Myocytes, Smooth Muscle; Nitric Oxide; Respiratory System; T-Lymphocytes

Topics: Asthma; Biomarkers; Chromatography, High Pressure Liquid; Humans; Inflammation Mediators; Leukotriene B4; Leukotriene C4; Leukotriene D4; Leukotriene E4; Radioimmunoassay; Reference Values; Specimen Handling; Status Asthmaticus

In persons with asthma, the cysteinyl leukotrienes possess multiple inflammatory properties in vitro and have long been considered to be a potentially important mediator of asthma and an attractive target for therapeutic intervention. Controlled clinical trials have documented the efficacy of leukotriene receptor antagonists in asthma treatment, but reservations about their use for asthma therapy center on two main issues: the heterogeneity of patient responses and their reduced potency relative to other asthma medications. For example, leukotriene receptor antagonists also have been shown to be less efficacious than inhaled corticosteroids for several end points, including symptom relief, reduced markers of inflammation, and improved pulmonary function. This review explores several underappreciated aspects of asthma therapy: heterogeneity of patient responses to medication, the failure of symptoms to correlate with commonly used end points, and the potential of delivery to distal airways for producing important and novel benefits.

Topics: Anti-Asthmatic Agents; Asthma; Dyspnea; Endpoint Determination; Humans; Leukotriene Antagonists; Leukotriene D4; Lung; Respiratory Function Tests

Cysteinyl-leukotrienes, i.e. leukotriene (LT) C4, D4 and E4, are inflammatory mediators and potent airway- and vasoconstrictors. Two different cysteinyl-leukotriene receptors, CysLT1 and CysLT2, have been cloned and functionally characterised using potent CysLT1 receptor antagonists and the dual CysLT1/CysLT2 receptor antagonist BAY u9773. However, the rank order of potency of the cysteinyl-leukotrienes at the CysLT receptors differs between tissues and studies, and a CysLT receptor classification based on agonist selectivity has not been established. In addition, the existence of more than two receptor subtypes for cysteinyl-leukotrienes has been suggested.

Topics: Animals; Asthma; Blood Vessels; Cysteine; Humans; Inflammation Mediators; Leukotriene D4; Leukotrienes; Membrane Proteins; Receptors, Leukotriene; Vasoconstriction; Vasoconstrictor Agents

Topics: Acetates; Administration, Oral; Animals; Asthma; Chromones; Chronic Disease; Cyclopropanes; Humans; Leukotriene Antagonists; Leukotriene D4; Lung; Quinolines; Sulfides

Aspirin is not only one of the best-documented medicines in the world, but also one of the most frequently used drugs of all times. In addition to its role as an analgesic, aspirin is being increasingly used in the prophylaxis of ischemic heart disease and strokes. The prevalence of aspirin intolerance is around 5 to 6%. Up to 20% of the asthmatic population is sensitive to aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) and present with a triad of rhinitis, sinusitis, and asthma when exposed to the offending drugs. This syndrome is referred to as aspirin-induced asthma (AIA). The pathogenesis of AIA has implicated both the lipoxygenase (LO) and the cyclooxygenase (COX) pathways. By inhibiting the COX pathway, aspirin diverts arachidonic acid metabolites to the LO pathway. This also leads to a decrease in the levels of prostaglandin (PG) E(2), the anti-inflammatory PG, along with an increase in the synthesis of cysteinyl leukotrienes (LTs). Evidence suggests that patients with AIA have increased activity of LTC(4) synthase, the rate-limiting enzyme in the cysteinyl LT synthesis, in their bronchial biopsy specimens, thereby tilting the balance in favor of inflammation. LT-modifying drugs are effective in blocking the bronchoconstriction provoked by aspirin and are used in the treatment of this condition. Aspirin desensitization has a role in the management of AIA, especially in patients who need prophylaxis from thromboembolic diseases, myocardial infarction, and stroke. This review covers the latest understanding of pathogenesis, clinical features, and management of AIA.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acids; Aspirin; Asthma; Bronchial Hyperreactivity; Cyclooxygenase Inhibitors; Desensitization, Immunologic; Dinoprostone; Drug Hypersensitivity; Glutathione Transferase; Humans; Leukotriene Antagonists; Leukotriene D4; Lipoxygenase; Rhinitis; Sinusitis

Leukotrienes can be generated from a wide variety of cells including mast cells and eosinophils. The biological properties of these products include bronchial smooth muscle contraction, stimulation of mucous production, enhancement of vascular permeability, and recruitment of eosinophils. These properties can contribute significantly to the pathobiology of asthma. Recently, zafirlukast and montelukast, and zileuton, leukotriene D4 receptor antagonists and 5-lipoxygenase inhibitors, respectively, have been developed and are available for treating asthma. Studies have found these compounds modify bronchospasm with exercise, the pulmonary reaction to aspirin in sensitive subjects, and the airway response to inhaled antigen. Furthermore, in patients with chronic asthma, leukotriene modifiers improve airflow obstruction, decrease the need for rescue medication, and diminish symptoms. Moreover, these drugs can prevent asthma exacerbations. However, there is little evidence that these medications have potent anti-inflammatory activity. Nonetheless, leukotriene modifiers represent new, and effective, therapeutics in the treatment of asthma; at present, the positioning of these products in relationship to inhaled corticosteroids, for example, in the treatment of asthma has not been fully defined but will emerge with further study and use in the clinic setting.

Topics: Asthma; Humans; Leukotriene Antagonists; Leukotriene D4; Lipoxygenase Inhibitors; Lung Diseases, Obstructive

Topics: Asthma; Humans; Leukotriene B4; Leukotriene C4; Leukotriene D4; Leukotriene E4

Peptide-leukotrienes (p-LTs) (LTC4, LTD4 and LTE4) are major metabolites of the arachidonate 5-lipoxygenase pathway. Although a number of papers have reported that p-LTs induce potent bronchial smooth muscle constriction as well as airway mucus secretion, vascular permeability and proliferation of airway smooth muscle cells, it had not been recognized that they are pivotal chemical mediators in asthmatic diseases until recently. Yet, several potent and selective antagonists against p-LTs and inhibitors of p-LT formation revealed that p-LTs play significant roles in not only allergic but non-allergic asthma including exercise- and aspirin-induced asthma. In addition, it has been reported that p-LTs participate in rhinitis, especially nasal blockage. In this article, recent development of drugs relating to p-LTs and their therapeutic effects for asthma are mainly reviewed.

Topics: Asthma; Humans; Leukotriene D4; Leukotrienes

Topics: Acetates; Asthma; Bronchi; Cyclopropanes; Humans; Hydroxyurea; Indoles; Leukotriene Antagonists; Leukotriene D4; Lipoxygenase Inhibitors; Membrane Proteins; Phenylcarbamates; Quinolines; Receptors, Leukotriene; Rhinitis; Sinusitis; Sulfides; Sulfonamides; Tosyl Compounds

Leukotrienes constitute a class of inflammatory mediators synthesised from arachidonic acid, a product of cell membrane metabolism. Synthesis occurs in the 5-lipoxygenase enzyme pathway, which produces several species of leukotrienes, each with characteristic biological activities. With regard to asthma, the leukotrienes are particularly important because of their ability to directly and potently mediate bronchoconstriction; in addition, they specifically stimulate the secretion of mucus into the airways and the extravasation of fluids and proteins into the airway tissues, both of which contribute to airway obstruction. A number of antileukotriene agents have been developed with the goal of modulating the inflammatory process in various disease states. These agents fall into 2 general classes: leukotriene receptor antagonists and leukotriene synthesis inhibitors. Results of antileukotriene agents in preclinical and clinical trials indicate that antileukotriene agents attenuate the response to challenges with inhaled leukotrienes, cold air, exercise, aspirin and allergen; in addition, they have shown efficacy in clinical asthma and have not been associated with serious adverse effects. Although results to date indicate that these medications are well tolerated and effective in the treatment of asthma, the recent approval by the FDA of 2 antileukotriene agents will give physicians further insight into how patients with asthma respond to them.

Topics: Asthma; Humans; Leukotriene D4; Receptors, Leukotriene

To explore the value of leukotriene D4 (LTD4) bronchial provocation test (BPT) in detection of airway hyper-responsiveness (AHR) in children.. A total of 151 children aged 6 to 14 years, including 86 in remission of asthma and 65 with acute bronchitis, who were followed up in our respiratory clinic between November, 2017 and August, 2018. The children were randomly divided into LTD4 group (78 cases) and methacholine (MCH) group (73 cases). In LTD4 group, the 78 children underwent LTD4-BPT, including 46 with asthma and 32 children having re-examination for previous episodes of acute bronchitis; in MCH group, the 73 children underwent MCH-BPT, including 40 with asthma and 33 with acute bronchitis. MCH-BPT was also performed in the asthmatic children in the LTD4 group who had negative responses to LTD4 after an elution period. The major adverse reactions of the children to the two BPT were recorded. The diagnostic values of the two BPT were evaluated using receiver-operating characteristic (ROC) curve.. There was no significant difference in the results of basic lung function tests between LTD4 group and MCH group (. LTD4-BPT had high safety in clinical application of children and was similar to the specificity of MCH-BPT. However, it had low sensitivity, low diagnostic value, and limited application value in children's AHR detection.

Topics: Adolescent; Asthma; Bronchial Provocation Tests; Child; Humans; Leukotriene D4; Methacholine Chloride; Respiratory Hypersensitivity

Correlation between fractional exhaled nitric oxide (FeNO) and responsiveness to inhaled leukotriene D4 (LTD4 ) and methacholine (MCh) might be different. This study aims to determine the correlation between FeNO and airway responsiveness to LTD4 and MCh, and to compare the airway responsiveness to inhaled LTD4 and MCh and FeNO in non-smokers, patients without rhinitis and non-smokers without rhinitis.. In this cross-over study, asthmatic patients and healthy subjects underwent LTD4 and MCh inhalation challenge at a 2- to 14-day interval. The FeNO was measured by using NIOX MINO, a portable instrument, at the initial visit, before spirometry and inhalation challenge tests. Subgroup analyses were performed in asthmatic patients based on the categorisation of never-smoker group, non-rhinitis group and never-smoker without rhinitis group.. Of 62 asthmatic patients enrolled, 43 did not have self-reported rhinitis (asthmatic patients without rhinitis), 56 were never-smokers (asthmatic non-smokers), giving rise to 37 non-smokers who did not have rhinitis (asthmatic non-smokers without rhinitis). Twenty-one healthy subjects were enrolled. Overall, Log10 FeNO correlated with Log10 PD20 FEV1 -MCh but not Log10 PD20 FEV1 -LTD4 or Log10 (LTD4 /MCh potency ratio). Reduced FeNO was associated with significantly higher Log10 PD20 FEV1 -MCh but not Log10 PD20 FEV1 -LTD4 , except for non-smokers. Compared with all asthmatic patients, asthmatic non-smokers without rhinitis were characterised by markedly reduced levels of Log10 PD20 FEV1 -MCh but not Log10 PD20 FEV1 -LTD4 . The difference in all parameters did not reach statistical significance among asthmatic patients without rhinitis, asthmatic non-smokers and asthmatic non-smokers without rhinitis.. FeNO correlates with airway responsiveness to inhaled MCh but not LTD4 , in asthmatic patients, particularly in asthmatic non-smokers without rhinitis.

Topics: Administration, Inhalation; Adult; Asthma; Bronchial Provocation Tests; Bronchoconstrictor Agents; Cross-Over Studies; Female; Humans; Leukotriene D4; Male; Methacholine Chloride; Middle Aged; Nitric Oxide; Treatment Outcome

The convenient measure to predict efficacy of leukotriene receptor antagonist is lacking.. To determine if leukotriene D4 inhalation challenge predicts short-term efficacy of montelukast in asthma.. In this open-labelled 28-day trial, 45 patients with asthma were allocated to leukotriene-sensitive and leukotriene-insensitive group to receive montelukast monotherapy (10 mg, once daily) based on the positive threshold of leukotriene D4 inhalation challenge test (4.800 nmol). Miscellaneous measurements comprised fractional exhaled nitric oxide, methacholine inhalation challenge, Asthma Control Test and Asthma Quality of Life Questionnaire. Peak expiratory flow was self-monitored throughout the treatment. End point assessments were performed 3 to 5 days after montelukast withdrawal.. Twenty-three patients in leukotriene-sensitive group and 10 leukotriene-insensitive group completed the study. Both groups differed neither in 28-day peak expiratory flow rate nor in maximal weekly peak expiratory flow (both P > 0.05). However, minimal weekly peak expiratory flow was significantly higher in leukotriene-insensitive group throughout the treatment course (all P < 0.05) except for week 1 (P > 0.05). Both groups did not differ statistically in the post-treatment improvement in forced expiratory volume in 1 s (FEV1 ) predicted% prior to inhalation challenge, fractional exhaled nitric oxide or the airway responsiveness to leukotriene D4 or methacholine (all P > 0.05). There was a marked increase in Asthma Control Test score and the symptom score of Asthma Quality of Life Questionnaire in both groups (both P < 0.05). The overall significance of Logistic regression model was unremarkable (P = 0.467).. Responsiveness to inhaled leukotriene D4 alone might not be sufficient to predict the short-term efficacy of montelukast monotherapy in patients with asthma.

Topics: Acetates; Administration, Inhalation; Adult; Asthma; Bronchial Provocation Tests; Cyclopropanes; Female; Forced Expiratory Volume; Humans; Leukotriene Antagonists; Leukotriene D4; Male; Middle Aged; Pilot Projects; Predictive Value of Tests; Quality of Life; Quinolines; Sulfides; Treatment Outcome; Young Adult

Response-dose ratio (RDR) and cumulative provocative dosage (PD) are useful indices reflecting airway responsiveness in asthma.. To compare the diagnostic value of RDR and PD, by conducting leukotriene D4 (LTD4-BPT) and methacholine bronchial provocation test (MCh-BPT), in different asthma control levels.. Healthy subjects and asthmatic patients underwent LTD4-BPT and MCh-BPT, at 2-14-day interval. This entailed assessment of the distribution characteristics, correlation, and diagnostic value of PD inducing 20% fall in forced expiratory volume in one second (PD20FEV1) and the RDR, defined as FEV1 fall (%) at the final step divided by the corresponding provocative dosage.. Twenty uncontrolled, 22 partly controlled, 20 controlled asthmatics, and 21 healthy subjects were enrolled. Log10RDR was positively correlated with log10PD20FEV1 in both BPTs (all P < 0.05). Poorer asthma control was associated with significantly lower PD20FEV1 and higher RDR (both P < 0.05). The differences in PD20FEV1 and RDR between partly controlled and controlled asthma were unremarkable (both P > 0.05). Compared with log10PD20FEV1, the log10RDR yielded similar diagnostic values in both BPTs. A lower percentile of RDR (≤ 25th percentile) was associated with higher baseline FEV1 (P < 0.05) and an increased proportion of well-controlled asthmatic patients. The combination of RDR and PD20FEV1 led to an increased diagnostic value compared with either parameter alone.. RDR is a surrogate of PD20FEV1 for BPTs in asthma. This finding was not modified by different asthma control levels or the types of bronchoprovocants.

Topics: Adult; Anti-Asthmatic Agents; Asthma; Bronchial Provocation Tests; Bronchoconstriction; Bronchodilator Agents; China; Cross-Over Studies; Dose-Response Relationship, Drug; Female; Forced Expiratory Volume; Humans; Leukotriene D4; Lung; Male; Methacholine Chloride; Middle Aged; Predictive Value of Tests; Vital Capacity

Both leukotriene D(4) (LTD(4)) and methacholine bronchial provocation tests are measurements of airway responsiveness; however, their correlation and distinction remain unexplored.. We sought to compare the 2 tests and classify leukotriene-responsiveness subtypes in asthmatic patients.. In this randomized cross-over study we enrolled healthy subjects and asthmatic patients with different control statuses. All subjects underwent both tests with a 2- to 14-day interval. Distribution and correlation of cumulative doses inducing a 20% decrease in FEV(1), LTD(4)/methacholine potency ratio, diagnostic value, and adverse events were recorded and analyzed. Asthmatic patients with a lower cumulative dose for LTD(4) and a higher leukotriene/methacholine potency ratio than geometric means were regarded as leukotriene responsive.. Twenty patients with uncontrolled, 22 with partly controlled, and 20 with controlled asthma and 21 healthy subjects were enrolled. Geometric means of cumulative doses for LTD(4) and methacholine (0.272 nmol vs 0.945 μmol) were lowest in patients with uncontrolled asthma, followed by those with partly controlled (0.387 nmol vs 1.933 μmol) and controlled (1.484 nmol vs 3.946 μmol) asthma. The average potency ratio was highest in those with partly controlled asthma (5000.2), followed by those with uncontrolled (3477.7) and controlled (2702.6) asthma. Eighteen leukotriene-responsive asthmatic patients (29.03%) with a cumulative dose of LTD(4) of 0.533 nmol or less and a potency ratio of 3647 or greater were identified. Adverse events, including tachypnea and chest tightness, were similar and mild. No serious adverse event was reported.. Diagnostic value and safety were ideal in both tests. The combination of cumulative dose for LTD(4) and potency ratio might be useful to identify leukotriene-responsive asthmatic patients.

Topics: Administration, Inhalation; Adult; Asthma; Bronchi; Bronchial Provocation Tests; Case-Control Studies; Cross-Over Studies; Humans; Leukotriene D4; Methacholine Chloride

Although leukotriene D4 (LTD4) is a potent bronchoconstrictor, little is known about airway responsiveness to LTD4 in asthmatics with different inflammation phenotypes.. To establish the methodology and investigate the distribution characters of airway responsiveness, diagnostic value and safety of LTD4 bronchial provocation test.. LTD4 bronchial provocation tests were performed in 62 asthmatics and 21 normal controls. Airway responsiveness was assessed based on the cumulative dosage causing a 20% fall in FEV(1) (PD(20)FEV(1)-LTD4) and was expressed as (median, interquartile range). The fall in spirometric parameters was plotted showing the distribution characters. The diagnostic value was assessed using receiver operation characteristic (ROC) curve. All adverse events were recorded during the test.. Airway responsiveness to LTD4 was significantly higher in asthmatics (0.410 nmol, 0.808 nmol) as compared with normal controls (5.00 nmol, 0.00 nmol). The decrease in spirometric parameters varied after bronchoprovocation, which was negatively correlated with PD(20)FEV(1)-LTD4, among which FEV(1) had a maximal slope (r = -0.524, P = 0.000). High diagnostic value (AUC: 0.914, 95%CI: [0.855, 0.974]) was revealed by ROC curve. The major adverse events were dyspnea (82.3%), chest tightness (72.6%), wheezing (32.3%) and coughing (25.8%) in asthmatics, which could overall be recovered within 15.0 minutes after inhalation of 200 ∼ 400 mcg salbutamol MDI. No serious adverse event was reported.. The established procedure of LTD4 bronchial provocation test is effective in the diagnosis of asthma and is well tolerated. Future studies are necessary to provide more evidences in terms of safety and efficacy. This may be helpful upon further application in clinical practice.

Topics: Adolescent; Adult; Aged; Asthma; Bronchial Provocation Tests; Cough; Dyspnea; Female; Humans; Leukotriene D4; Male; Middle Aged; Respiratory Sounds; ROC Curve; Young Adult

Leukotriene D(4) (LTD(4)) is a central mediator in asthma inducing bronchoconstriction and profound disturbances in pulmonary gas exchange in asthmatic subjects. The aim of the study was to compare, for the first time, the influence of the bronchodilators salbutamol (400 μg) and ipratropium (80 μg) on lung function changes induced by inhaled LTD(4).. Treatments were evaluated in a randomized, three-period, double-blind, placebo-controlled, cross-over study where spirometric and pulmonary gas exchange indices were followed in 12 subjects with mild asthma before and after LTD(4) challenge.. Compared with placebo, salbutamol provided significant protection against the fall in FEV(1) (forced expiratory volume in 1 s) after LTD(4) challenge. Salbutamol also abolished the LTD(4)-induced gas exchange disturbances [decreased arterial oxygen tension (PaO(2)) and increased alveolar-arterial oxygen tension difference (AaPO(2))]. Ipratropium provided significant but less marked attenuation of the changes in FEV(1) and arterial oxygenation induced by LTD(4).. Despite the equal bronchodilatory effects of salbutamol and ipratropium before the challenge with LTD(4), salbutamol was superior to ipratropium in preventing spirometric and gas exchange abnormalities. This result indicates a broader action of salbutamol on several of the disturbances that contribute to airway obstruction including, for example, exudation of plasma in the airway mucosa. The clinical implication of this new finding is that in this model of acute asthmatic airway obstruction, salbutamol was more effective than ipratropium.

Topics: Administration, Inhalation; Adult; Airway Obstruction; Albuterol; Arteries; Asthma; Bronchoconstriction; Bronchodilator Agents; Cross-Over Studies; Double-Blind Method; Female; Forced Expiratory Volume; Humans; Ipratropium; Leukotriene D4; Male; Oxygen; Pulmonary Alveoli; Pulmonary Gas Exchange; Spirometry; Young Adult

The bronchoconstriction caused by inhaled neurokinin A (NKA) in patients with asthma is indirect. The mediators involved in NKA-induced bronchoconstriction are unknown. Studies with various H1 receptor antagonists were negative, making an important contribution of histamine unlikely. To study the role of cysteinyl leukotrienes in neurokinin A-induced bronchoconstriction, we performed a randomised, double-blind, cross-over, placebo controlled trial in 12 patients with mild to moderate asthma. Zafirlukast and matching placebo were given orally, 40 mg the evening before and 40 mg the morning of assessment. In one period NKA was administered, in the other period leukotriene D4 (LTD4). Increasing concentrations of NKA and LTD4 were inhaled from a 30 L bag, after nebulization via a Mallinckrodt nebuliser. The difference between log10PC20LTD4 after treatment with placebo or zafirlukast was highly significant (p<0.0001). A trend was observed towards a difference between log10PC20 neurokinin A after treatment with placebo or zafirlukast (p=0.0741). The dose ratio for the neurokinin A provocation was 4.4 and for the LTD4 provocation 67.7. In conclusion, zafirlukast had a large inhibitory effect on LTD4-induced bronchoconstriction, but offered only limited protective effect against neurokinin A-induced bronchoconstriction. We suggest that leukotrienes play a limited role in the bronchoconstrictor effect of neurokinin A in patients with asthma.

Topics: Adult; Arachidonate 5-Lipoxygenase; Asthma; Bronchial Provocation Tests; Bronchoconstriction; Cross-Over Studies; Dose-Response Relationship, Drug; Double-Blind Method; Glutathione Transferase; Humans; Indoles; Leukotriene Antagonists; Leukotriene D4; Neurokinin A; Phenylcarbamates; Polymorphism, Genetic; Sulfonamides; Tosyl Compounds

Inhaled corticosteroids are highly effective in asthma, reducing inflammatory markers and bronchial hyperresponsiveness. Cysteinyl-leukotrienes are major mediators of airway obstruction and display proinflammatory effects. Although the synthesis of leukotrienes is not affected by corticosteroid treatment, the influence of corticosteroids on the leukotriene pathway remains unresolved.. We investigated whether or not bronchial responsiveness to leukotriene (LT) D(4) is reduced by fluticasone propionate in subjects with asthma.. In 13 subjects with mild asthma, inhalation challenges with methacholine and LTD(4) were performed on consecutive days before and after 2 weeks of treatment with inhaled fluticasone 500 mug, twice daily, in a double-blind, randomized, placebo-controlled study with crossover design and 3 weeks of washout between periods. Exhaled nitric oxide was measured as a marker of corticosteroid responsiveness, and baseline urinary LTE(4) concentrations as an index of cysteinyl-leukotriene biosynthesis.. Fluticasone produced a significant decrease in methacholine responsiveness, corresponding to 2.6-fold shift in the PD(20) FEV(1), and a significant reduction in the levels of exhaled nitric oxide. By contrast, bronchial responsiveness to LTD(4) in the same subjects was unaffected by fluticasone, as were urinary LTE(4) concentrations.. These new data indicate that neither the biosynthesis nor the actions of leukotrienes appear to be sensitive to inhaled corticosteroids.. The study provides mechanistic support for the additive therapeutic efficacy of antileukotrienes and inhaled corticosteroids in asthma.

Topics: Administration, Inhalation; Adult; Androstadienes; Asthma; Bronchi; Cross-Over Studies; Double-Blind Method; Female; Fluticasone; Humans; Leukotriene D4; Leukotriene E4; Male; Methacholine Chloride

Bronchoprovocation with cysteinyl-leukotrienes (LTs) induces airflow obstruction and gas exchange abnormalities, namely ventilation-perfusion ratio (V'(A)/Q') imbalance. However, it is unknown which of the two different receptors for cysteinyl-LTs mediate these V'(A)/Q' disturbances. In a double-blinded, crossover design, 10 patients with mild asthma were randomised to receive an oral single dose of the selective cysteinyl-LT1 receptor antagonist montelukast (40 mg) or placebo before leukotriene (LT)D4 inhalation challenge. Gas exchange, including V'(A)/Q' descriptors were measured at baseline, 3 h after montelukast/placebo pretreatment and 5, 15 and 45 min after the LTD4 challenge. Compared with montelukast, inhalation of LTD(4) induced a marked fall in forced expiratory volume in one second (mean+/-se 33+/-2%) and profound V'(A)/Q' mismatching, reflected by a decreased arterial oxygen tension (from 100+/-4 to 75+/-3 mmHg) and an increased overall index of V'(A)/Q' heterogeneity dispersion of retention minus excretion inert gases corrected for dead space (from 4.9+/-1.2 to 8.4+/-1.1; normal< or =3.0; dimensionless), 5 min after placebo. Following montelukast, LTD4 produced no significant changes in any of the variables. In conclusion, these findings point to the view that leukotriene D4)-induced gas exchange disturbances and bronchoconstriction are both mediated by the cysteinyl-leukotriene1 receptor.

Topics: Acetates; Adult; Asthma; Bronchial Provocation Tests; Cross-Over Studies; Cyclopropanes; Double-Blind Method; Female; Humans; Hypoxia; Leukotriene Antagonists; Leukotriene D4; Male; Membrane Proteins; Quinolines; Receptors, Leukotriene; Severity of Illness Index; Sulfides; Ventilation-Perfusion Ratio

The clinical heterogeneity of asthma suggests that the contribution of genetic variability in candidate gene loci to well-defined phenotypes, such as atopy, may be examined to identify appropriate genetic risk factors for asthma. The gene encoding the cysteinyl leukotriene 2 (CysLT2) receptor has been implicated in atopy since it is localized to a region of chromosome 13q14 that has been linked to atopy in several populations and the cysteinyl leukotrienes are known to activate eosinophils and mast cells in atopy. Accordingly, we analysed the contribution of CysLT2 receptor gene variation to atopy in the inhabitants of Tristan da Cunha, a population characterized by both a founder effect and a 47% prevalence of atopy. Single-stranded conformational polymorphism analysis revealed four variants. Among these, the M201V [corrected] variant was activated with four-fold less potency by leukotriene D4 (LTD4) in a calcium flux assay. The CysLT2 receptor partial agonist, BAY u9773, also showed four-fold lower potency on the M201V [corrected] variant. The M201V [corrected] mutation is located within the extracellular region of the fifth transmembrane spanning domain of CysLT2 receptor, a position that may alter ligand binding and effector signalling. The novel M201V [corrected] CysLT2 receptor variant was associated with atopy (21%) on Tristan da Cunha compared with those who were non-atopic (7%) (Fisher's exact test, P=0.0016) in a manner that was independent of asthma (two-way ANOVA, P=0.0015). This represents the first association of a coding mutation in the CysLT2 receptor gene, located on chromosome 13q14, with the atopic phenotype found in the Tristan da Cunha population.

Topics: Asthma; Atlantic Islands; Black or African American; Calcium; Case-Control Studies; Chromosomes, Human, Pair 13; DNA; DNA Primers; Founder Effect; Genetic Variation; Humans; Hypersensitivity, Immediate; Leukotriene D4; Membrane Proteins; Phenotype; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Polymorphism, Single-Stranded Conformational; Receptors, Leukotriene; SRS-A; White People

Prostaglandin E2 is a potent immunomodulator that inhibits the early and late bronchoconstriction to inhaled allergen, as well as inhibiting the acute allergen-induced release of mediators into the human airway. To determine if the stable prostaglandin E agonist misoprostol could alter the late allergic formation of mediators we measured the appearance of eosinophils and key cytokines in the bronchoalveolar lavage fluid 24 h after allergen instillation.. Six atopic asthmatics underwent bronchoscopy, alveolar lavage and antigen instillation followed 24 h later by bronchoalveolar lavage. Eosinophil counts were done, together with measurements of IL-4, IL-5, eotaxin, RANTES and cysteinyl leukotrienes by immunoassay. The study was done in randomized blinded fashion while the volunteers took placebo or 600 microg of misoprostol four times a day (QID).. Misoprostol significantly decreased the appearance of IL-5 late after allergen challenge. Eotaxin levels were reduced, but not statistically significantly. Eosinophil number, RANTES, eosinophil cationic protein and cysteinyl leukotrienes were not altered by misoprostol.. Misoprostol reduces the formation of IL-5 late after allergen challenge, perhaps by inhibiting eosinophil, mast cell, and/or T lymphocyte production of IL-5. Despite decreases in IL-5 and eotaxin, eosinophils were recruited and activated by allergen.

Topics: Adult; Asthma; Blood Proteins; Bronchoalveolar Lavage Fluid; Chemokine CCL11; Chemokines, CC; Eosinophil Granule Proteins; Eosinophils; Humans; Hypersensitivity, Immediate; Interleukin-5; Leukotriene D4; Middle Aged; Misoprostol; Ribonucleases

Heparin besides its anticoagulant properties, possesses anti-inflammatory actions. Inhaled heparin has been shown to reduce early and late phase of asthmatic reaction and suppresses allergen induced rise in bronchial hyperreactivity. The exact mechanism of heparin action in bronchial asthma remains obscure. The mechanism involved in the control of bronchial hyperreactivity by heparin has been studied little and is yet poorly understood. The purpose of the present study was to investigate the effect of inhaled heparin on the airway response to leukotriene D4 Fourteen children with typical history of mild atopic asthma participated in this randomized, double-blind, placebo controlled and cross-over study. At the first visit subjects underwent provocation challenge test with leukotriene D4. Patients came back 14 days later to inhale heparin or placebo followed by provocation test with leukotriene. The third study day was 14 days after the second day and provocation test was performed in the same manner except for that patients who inhaled heparin at the second visit, now were administered placebo and opposite. Ten patients completed the study. One patient was withdrawn from the study because of consent withdrawal and three patients were unable to complete the provocation test because of asthma exacerbation. Single dose of inhaled heparin significantly decreased bronchial hyperreactivity to leukotriene in children with mild asthma (p = 0.005). PC20L after heparin inhalation increased in eight patient and decreased in two. It has been shown that histamine, metacholine, and leukotriene play a role in eosinophil recruitment to the airway. Since histamine, metacholine and leukotriene act through receptor binding to protein G, it is possible that heparin (by displacing eosinophil proteins from receptor-protein G binding) restore binding between receptor and G protein and in such mechanism, decrease bronchial hyperreactivity to leukotriene. In our study heparin was inhaled just before leukotriene provocation test and thus the effect of heparin on eosinophil proteins is less likely possible.

Topics: Administration, Inhalation; Adolescent; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Child; Cross-Over Studies; Double-Blind Method; Heparin; Humans; Leukotriene D4

Cysteinyl leukotrienes (cysteinyl-LTs) have been implicated in the pathogenesis of allergen induced airway responses. Airway responsiveness (AR) to inhaled cysteinyl-LTs is dramatically increased following allergen challenge in animal studies. The effect in man has not been evaluated.. Ten mild steroid-naïve asthmatic subjects with an isolated early asthmatic response (EAR) and 21 with an additional late asthmatic response (LAR) took part in a randomised controlled crossover study to assess AR to inhaled methacholine (MCh) and cysteinyl-LT D(4) (LTD(4)) 22 and 24 hours, respectively, after allergen challenge. Eight subjects had two further LTD(4) challenges separated by a 2 week washout period to assess the reproducibility of inhaled LTD(4) challenge.. In subjects with an isolated EAR, non-significant mean (SE) increases in AR of 0.4 (0.4) doubling doses (DD) for MCh and 0.4 (0.5) DD for LTD(4) followed allergen challenge compared with control. A significant correlation between AR to MCh and LTD(4) followed both control (r=0.91, 95% CI 0.67 to 0.98; p=0.0002) and allergen challenge (r=0.79, 95% CI 0.32 to 0.95; p=0.0063). In subjects with an additional LAR there was a significant increase in AR to MCh (1.2 (0.3) DD, p=0.0005) following allergen challenge but no overall effect on AR to LTD(4) (0.69 (0.4) DD, p=0.11). A significant correlation between AR to MCh and LTD(4) was again observed (r=0.70; 95% CI 0.38 to 0.87; p=0.0004) following control, although it was reduced following allergen challenge (r=0.48; 95% CI 0.063 to 0.76; p=0.027). LTD(4) challenge was highly reproducible with a mean difference of 0.2 (0.3) DD between challenges.. Allergen challenge significantly increases AR to inhaled MCh but not to LTD(4) in subjects with LAR. The lack of a comparable increase in AR to LTD(4) is surprising. Endogenous cysteinyl-LTs are produced in abundance following allergen challenge and may enhance AR to MCh or induce a degree of tachyphylaxis to LTD(4).

Topics: Administration, Inhalation; Adult; Allergens; Asthma; Bronchi; Bronchial Provocation Tests; Bronchoconstrictor Agents; Cross-Over Studies; Dose-Response Relationship, Drug; Female; Humans; Leukotriene D4; Male; Methacholine Chloride; Reproducibility of Results; Sensitivity and Specificity

Allergen-induced late airway responses are associated with increased numbers of airway eosinophils and basophils. The purpose of this study was to compare and contrast the effects of inhaled cysteinyl leukotrienes LTD(4) and LTE(4), which are released during allergen- induced airway responses, and allergen, on airway inflammatory cells. Fifteen subjects with atopic, mild asthma inhaled diluent, LTD(4), LTE(4), and allergen. Spirometry was performed for 7 h, and sputum inflammatory cells were measured before, 7 h, and 24 h after challenges. The maximum early percent fall in FEV(1) was 23.6 +/- 1.4%, 21.6 +/- 2.3%, 29.3 +/- 2.4%, and 4.0 +/- 1.1% after LTD(4), LTE(4), allergen, and diluent, respectively. Only inhaled LTE(4) and allergen significantly increased sputum eosinophils at 7 h and 24 h, and sputum basophils at 7 h. Six additional subjects underwent airway biopsies 4 h after inhalation. There were significantly more eosinophils in the lamina propria after inhalation of LTE(4) compared with LTD(4) and diluent (p < 0.05). These results suggest cysteinyl leukotrienes play a role in eosinophil migration into the airways in allergic asthma, and for the same degree of bronchoconstriction, inhaled LTE(4) causes more tissue and airway eosinophilia than LTD(4).

Topics: Administration, Inhalation; Adult; Asthma; Basophils; Cross-Over Studies; Double-Blind Method; Eosinophils; Female; Humans; Leukotriene D4; Leukotriene E4; Male; Mast Cells

Inhaled cysteinyl leukotrienes may cause recruitment of eosinophils into asthmatic airways. We compared the effects of inhaled leukotriene D4 (LTD4), methacholine, and allergen on airway eosinophils in 10 nonsmoking, atopic, mildly asthmatic subjects in a double-blind, diluent-controlled, randomized crossover study. Concentrations of LTD4, methacholine, and allergen resulting in a 30% decrease in FEV1, and diluent controls (ethanol and saline), were inhaled with at least 7 d between challenges. Spirometry was conducted for 4 h after inhalation challenge, and airway hyperresponsiveness (AHR) to methacholine was measured before and 24 h after challenge. Sputum was induced before and 4 h, 7 h, and 24 h after challenge. The maximum decrease in FEV1 was 31.4 +/- 1.8% with LTD4, 39.4 +/- 2.8% with methacholine, and 30.1 +/- 3.4% with allergen. AHR to methacholine, at the provocative concentration causing a 20% decrease in FEV1 (PC20), was enhanced 24 h after allergen challenge, but remained unchanged 24 h after LTD4 and methacholine (p > 0.05). The percentage of eosinophils in sputum was increased after inhalation of allergen at 7 h and 24 h (p = 0.003), but not after LTD4 or methacholine (p = 0.70). We demonstrated that neither inhalation of LTD4 nor of methacholine at concentrations causing submaximal bronchoconstriction increases the number of sputum eosinophils in the airways of mildly asthmatic subjects. However, LTD4 may still be an important cofactor for eosinophil recruitment in asthma.

Topics: Administration, Inhalation; Adult; Allergens; Asthma; Bronchoconstrictor Agents; Cross-Over Studies; Double-Blind Method; Eosinophilia; Female; Forced Expiratory Volume; Humans; Leukotriene D4; Male; Methacholine Chloride; Respiratory Hypersensitivity; Respiratory System; Spirometry; Sputum

From bronchoprovocation studies and investigations of the acute effects of drugs that inhibit leukotrienes (LT), the hypothesis has emerged that leukotrienes are important mediators of airway obstruction and other symptoms in aspirin-intolerant asthma (AIA). However, it has yet not been shown if subjects with AIA respond favorably to clinical treatment with leukotriene inhibitors. Therefore, in a double-blind placebo-controlled crossover study, we examined the effects of 6 wk of treatment with the leukotriene-pathway inhibitor zileuton (600 mg, four times daily) in 40 patients with well-characterized AIA. The treatment was added to existing therapy, which included medium to high doses of inhaled (average daily dose 1,030 microg of beclomethasone or budesonide) or oral glucocorticosteroids (4 to 25 mg/d) for all but one of the patients. On top of this treated baseline, there were no significant effects of adding placebo, indicating that their asthma was kept relatively stable. However, there was an acute and chronic improvement in pulmonary function after treatment with zileuton, expressed both as increased FEV1 from baseline compared with placebo, and higher morning and evening peak expiratory flow rate (PEFR) values on zileuton treatment compared with placebo. The improvements occurred despite lower use of rescue bronchodilator with zileuton. Zileuton also diminished nasal dysfunction, which is one of the cardinal signs of AIA. There was a remarkable return of smell, less rhinorrhea, and a trend for less stuffiness and higher nasal inspiratory flow during treatment with zileuton. Zileuton caused a small but distinct reduction of bronchial hyperresponsiveness to histamine and inhibited aspirin-induced bronchoconstriction. Zileuton inhibited urinary excretion of LTE4 but did not change airway reactivity to inhaled LTD4, supporting that zileuton specifically inhibited leukotriene biosynthesis. The findings indicate that leukotrienes are important mediators of persistent airway obstruction and chronic nasal dysfunction in AIA. The study also suggests that addition of a leukotriene pathway inhibitor such as zileuton may bring about greater control of asthma than what is achieved by treatment with medium to high doses of glucocorticosteroids alone.

Topics: Adrenergic beta-Agonists; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Cross-Over Studies; Double-Blind Method; Drug Therapy, Combination; Female; Forced Expiratory Volume; Glucocorticoids; Histamine; Humans; Hydroxyurea; Leukotriene Antagonists; Leukotriene D4; Lipoxygenase Inhibitors; Male; Middle Aged; Peak Expiratory Flow Rate

Previous studies demonstrated that leukotriene receptor antagonists (LTRAs) are effective in reducing asthma symptoms and the airway response to inhaled leukotriene D4 (LTD4) in asthmatic patients receiving inhaled beta2-agonists alone.. To investigate the efficacy of a single 20-mg dose of the oral LTRA zafirlukast in reducing the airway response to inhaled LTD4 in mild-to-moderate asthmatic patients receiving inhaled beta2-agonists and inhaled corticosteroids (ICS).. In this double-blind, crossover trial, six patients on maintenance ICS (median dose 800 microg/day; range 336 to 1600 microg/day), who had a 20% decrease in FEV1 following inhalation of a maximal concentration of 50 microg/mL LTD4, received either zafirlukast or placebo on each of two study days. Two hours after dosing, patients underwent bronchoprovocation challenges with increasing concentrations of LTD4 (0.1 to 1000 microg/mL) at 10-minute intervals until either the patient's FEV1 decreased by 20% or the maximum concentration of LTD4 was given. Spirometric tests were done just before (baseline) and throughout the challenge phase until the patient's FEV1 returned to within 5% of baseline. Blood samples were collected two hours after dosing to determine plasma concentrations of zafirlukast.. Compared with placebo, zafirlukast produced a 1.82-unit increase in logPC20FEV1 and a 1.88-unit increase in logPD20FEV1, representing a 66-fold higher concentration and a 76-fold higher dose of LTD4, respectively, to produce a 20% decrease in FEV1 (P < .001). Mean time to recovery after challenge was 36.7 versus 51.7 minutes when patients received zafirlukast and placebo, respectively. No correlation between clinical effects and plasma drug levels was observed.. This trial demonstrated that asthmatic patients on maintenance ICS can respond to exogenously administered LTD4 and that zafirlukast reduced the airway response to LTD4 in these patients.

Topics: Administration, Inhalation; Adrenal Cortex Hormones; Adult; Anti-Asthmatic Agents; Asthma; Bronchoconstriction; Cross-Over Studies; Double-Blind Method; Female; Humans; Indoles; Leukotriene D4; Male; Phenylcarbamates; Sulfonamides; Tosyl Compounds

The cysteinyl leukotriene LTE4 has been shown to induce airway eosinophilia in asthmatics in vivo. This phenomenon has not yet been reported for LTD4. Hence, we examined the effect of inhaled LTD4 and a control bronchoconstrictor agent, methacholine, on cell differentials in hypertonic saline-induced whole sputum samples of 12 nonsmoking atopic asthmatic subjects (three women, nine men; 21 to 29 yr of age; FEV1, 74 to 120% pred; PC20FEV1 methacholine < 9.6 mg/ml). The study had a cross-over, placebo-controlled design consisting of 4 d separated by > or = 1 wk. On each randomized study day, the subjects inhaled five serial doses of either LTD4 (mean cumulative concentration: 95.7 microM) or methacholine (mean cumulative concentration: 542 mM) or five doses of their respective diluents (PBS/ethanol or PBS). The airway response was measured by FEV1, followed by sputum induction with 4.5% NaCl, 4 h postchallenge. Inflammatory cells (> or = 250) were counted twice on coded cytospins and expressed as percentages of nonsquamous cells. There was no significant difference in the maximal percent fall in FEV1 from baseline between LTD4 (mean +/- SEM, 49.5 +/- 4.4% fall) and methacholine (mean +/- SEM, 55.9 +/- 3.4% fall) (p = 0.11). LTD4 induced a significant increase in the percentage of sputum eosinophils as compared with its diluent (mean +/- SD, 26.6 +/- 21.3% and 10.2 +/- 8.8%, respectively; p = 0.025), whereas a similar trend for methacholine failed to reach significance (mean +/- SD, 19.1 +/- 22.9% and 7.8 +/- 5.8%, respectively; p = 0.11). There was no significant difference in the changes in the percentage of sputum eosinophils between LTD4 and methacholine (mean difference +/- SD, 7.5 +/- 12.5% eosinophils; p = 0.09). We conclude that LTD4 induces eosinophilia in sputum of asthmatic subjects 4 h after inhalation. Our data suggest that LTD4 recruits eosinophils into the airways of asthmatics in vivo, possibly by virtue of direct or indirect chemotactic properties, whereas an additional effect of vigourous airway narrowing per se cannot be excluded.

Topics: Administration, Inhalation; Adult; Asthma; Bronchial Provocation Tests; Bronchoconstrictor Agents; Cell Count; Cross-Over Studies; Eosinophils; Female; Humans; Leukotriene D4; Male; Methacholine Chloride; Pulmonary Eosinophilia; Sputum

Cysteinyl leukotrienes mediate signs and symptoms of asthma. In a double-blind, placebo-controlled, crossover study, a new potent and specific cysteinyl leukotriene (LTD4) receptor antagonist, montelukast (MK-0476), was evaluated for tolerability and clinical efficacy in patients with chronic asthma (receiving and not receiving inhaled corticosteroids).. Twenty-nine nonsmoking patients with asthma (15 treated concomitantly with inhaled corticosteroids) with FEV1 percent predicted values between 50% to 80% received MK-0476, 200 mg, or placebo three times daily for 10 1/3 days (31 doses) in a random, crossover manner, after a 2-week, open, baseline period. Comparisons in FEV1 (mean percent change from baseline after the first and last dose), mean daily daytime asthma and nocturnal awakening scores, and mean daily beta-agonist use were made between treatment periods.. Montelukast, compared with placebo, caused improvements in FEV1 (mean percentage point difference of the percentage change from baseline) 3 and 4 hours after dosing on day 1 (hour 3, 9.0%; 95% confidence interval [CI] 0.53, 18.72; hour four, 10.9%; 95% CI -0.25, 20.20) and day 11 (hour 3, 14.0%; 95% CI 0.76, 31.43; hour 4, 13.4%; 95% CI 1.24, 28.83). Reductions were observed in mean daily beta-agonist use (1.0 puff/day [95% CI -1.61, -0.26]), mean daytime symptom scores, and nocturnal awakenings over the 10 1/3 day treatment period. There were no important differences between the groups receiving and those not receiving inhaled corticosteroids. Montelukast was well tolerated with no serious clinical adverse events reported.. In this study Montelukast, 200 mg, administered three times daily for 10 1/3 days, compared with placebo, was generally well tolerated and resulted in significant improvement in chronic asthma, irrespective of the presence of inhaled corticosteroids.

Topics: Acetates; Adolescent; Adrenal Cortex Hormones; Adult; Asthma; Chronic Disease; Cross-Over Studies; Cyclopropanes; Double-Blind Method; Drug Administration Schedule; Female; Forced Expiratory Volume; Humans; Leukotriene Antagonists; Leukotriene D4; Male; Membrane Proteins; Middle Aged; Quinolines; Receptors, Leukotriene; Sulfides

The pharmacokinetics of pranlukast, a leukotriene LTD4 antagonist, were studied in 48 young, healthy subjects after single and repeated oral doses (given every 12 h) ranging from 112.5 to 675 mg. The doses were administered 30 minutes after a light breakfast.. Maximal drug concentrations generally occurred between 2 and 6 h after dosing, and there was some evidence of an absorption lag-time. Secondary peaks were observed in the plasma concentration vs. time profiles of many of the study subjects after both single and repeated doses, particularly during the period of maximum drug absorption. In general, after both single and repeated doses, there were related increases in the corresponding Cmax and AUC with a rise in dose, although the increase was diminished at doses above 450 mg. With repeated dosing of pranlukast the mean AUC was generally higher (up to 1.6-fold), and the higher plasma concentrations allowed characterisation of a longer mean t 1/2 than after single dose administration. The mean steady-state trough plasma concentrations attained after evening doses were considerably higher (up to 14-fold) than those obtained after the morning dose.. The data suggested that the pharmacokinetics of pranlukast are influenced by the time of dosing. Based on analysis of urinary 6 beta-hydroxycortisol excretion, there was no evidence that pranlukast modified the metabolic activity of cytochrome P-450 3A isoenzymes.

Topics: Adolescent; Adult; Asthma; Chromones; Cytochrome P-450 Enzyme System; Dose-Response Relationship, Drug; Double-Blind Method; Humans; Leukotriene D4; Middle Aged

1. Mast cell mediators PGD2 and LTD4 may play important roles in asthma pathogenesis. There is little information on the repeatability of inhalation challenge with these agonists in the laboratory. 2. We assessed the repeatability of inhalation challenges using PGD2 and LTD4 in two groups of 10 asthmatic volunteers. Non-specific bronchial responsiveness was assessed by histamine inhalation challenges. 3. Using the Bland-Altman method, we found the coefficient of repeatability to be 1.2 doubling doses for LTD4 and 2.1 for PGD2 at a 1 week interval. Repeatability for histamine inhalation challenge over the same time period was similar at 1.4 and 2.1 doubling doses respectively. 4. Non-specific bronchial responsiveness following LTD4 challenge decreased significantly, mean PD20FEV1 increasing from 169 nmol on day 1 to 278 nmol on day 3 (P = 0.001), before returning to baseline levels. 5. A progressive decrease in non-specific bronchial responsiveness occurred following PGD2 challenge. Baseline PD20FEV1 was 195 nmol, increasing to 238 nmol by day 3 (NS) and 313 nmol by day 8 (P = 0.016). 6. PGD2 inhalation challenges performed a week apart are less reproducible than LTD4 challenges, possibly as a result of significant changes in histamine bronchial responsiveness. Our findings allow accurate power calculations to be made for studies to assess new pharmacological antagonists to these mediators.

Topics: Administration, Inhalation; Adolescent; Adult; Airway Resistance; Analysis of Variance; Asthma; Bronchial Provocation Tests; Female; Forced Expiratory Volume; Humans; Leukotriene D4; Male; Middle Aged; Prostaglandin D2; Reproducibility of Results

Cysteinyl leukotrienes are potent inflammatory mediators that are considered to play a role in the pathophysiology of asthma. It can be postulated that leukotrienes exert their bronchoconstricting effects, in part, through secondary release of endogenous neuropeptides. We examined the effect of inhaled thiorphan, an inhibitor of a neuropeptide degrading enzyme, on the concentration-response curve to leukotriene D4 (LTD4) in a two-period, double-blind, cross-over and placebo-controlled study, in 16 nonasthmatic and 12 asthmatic subjects. Thiorphan or placebo were aerosolized and administered in two 0.5 ml doses of 1.25 mg.ml-1 each, 10 min prior to LTD4 inhalation. The airway response was measured by forced expiratory volume in one second (FEV1) and partial expiratory flow-volume curves (expiratory flow at 40% of forced vital capacity; V40p), and expressed as % fall from baseline. Complete concentration-response curves to inhaled LTD4 were recorded and characterized by their position (provocative concentration producing a 20% fall in FEV1 and a 40% fall in V40p; PC20FEV1 and PC40 V40p) and, in the nonasthmatics, also by the maximal-response plateau (MFEV1, MV40p). Post-pretreatment baseline values of FEV1 and V40p were not different between thiorphan and placebo pretreatment. In both groups of subjects, there was no significant difference in lnPC40V40p or lnPC20FEV1 to LTD4 between the two pretreatments mean difference +/- SD (in doubling concentrations): 0.12 +/- 0.73 and -0.19 +/- 1.23, respectively, in asthmatics; and 0.17 +/- 0.95 and -0.99 +/- 1.95, respectively, in nonasthmatics. The maximal-response plateau could not be obtained in the majority of the asthmatic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Administration, Inhalation; Adult; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Double-Blind Method; Forced Expiratory Volume; Humans; Leukotriene D4; Male; Neprilysin; Thiorphan

RG 12525 is a new oral leukotriene D4 (LTD4) antagonist with proven activity in animal and human models of leukotriene-induced bronchoconstriction. In this randomized, double-blind, parallel-group, placebo-controlled study the bronchodilator effects of single oral doses of RG 12525 of 25 and 200 mg or placebo were evaluated in 62 adult asthmatic patients. All patients had previously demonstrated 20% reversibility of FEV1 with an inhaled beta-agonist. They had an unmedicated FEV1 less than 80% of predicted value at the time of the study. Bronchodilator activity was assessed by spirometry before and at multiple time points after dosing for eight hours. A single 200-mg dose of RG 12525 of mg resulted in statistically significantly greater increases in mean maximum change above baseline for FEV1 and FEF25-75% than placebo. The peak effect was observed four to five hours after dosing. The RG 12525 dose of 25 mg dose induced better bronchodilation than placebo but the differences were not significant. Adverse clinical experiences or laboratory abnormalities were not noted.

Topics: Adolescent; Adult; Asthma; Double-Blind Method; Female; Humans; Leukotriene D4; Lung; Male; Patient Dropouts; Placebos; Quinolines; Respiratory Function Tests; Tetrazoles

The hypothesis that cysteinyl-leukotrienes (LTC4, LTD4 and LTE4) are mediators of allergen-induced airway obstruction in asthmatics was tested with the specific receptor antagonist ICI-204,219, in a double-blind, placebo-controlled, randomized, cross-over bronchoprovocation study. On three occasions, cumulative bronchial challenge with specific allergen was performed in 10 males with mild allergic asthma. The first control session established the baseline provocative dose of allergen producing a decrease in forced expiratory volume in one second (FEV1) by 20% (PD20FEV1). The two rechallenges were performed 2 h after oral administration of placebo or 20 mg of ICI-204,219. The allergen dose-response relations were highly reproducible, producing PD20 values at the control session and after placebo treatment which varied by no more than 0.7-1.3 fold (95% confidence interval (95% CI)). After ICI-204,219, the median cumulated allergen dose was 5.5 fold higher, and the group geometric mean PD20 was increased 2.5 times. Furthermore, the recovery time after the immediate bronchoconstriction was shorter (40 vs 60 min). The wheal and flare responses to intradermally injected LTD4 were somewhat inhibited by ICI-204,219, whereas responses to histamine were unaffected. However, the findings suggest that skin testing with LTD4 is unlikely to predict the degree of leukotriene-antagonism in the airways. The findings confirm and extend the indications that cysteinyl-leukotrienes are important mediators of allergen-induced airway obstruction, and that leukotriene-antagonists should be evaluated as a potential new therapy in allergic asthma.

Topics: Adult; Allergens; Asthma; Bronchial Provocation Tests; Double-Blind Method; Forced Expiratory Volume; Humans; Indoles; Leukotriene D4; Male; Phenylcarbamates; Reproducibility of Results; Skin Tests; Sulfonamides; Tosyl Compounds

Three inhalation formulations of ICI 204,219 were compared for antagonism of antigen-induced bronchoconstriction in 16 subjects with asthma who demonstrated reproducible hypersensitivity to allergen during screening challenges. Each subject received a single 0.2-mg dose of each formulation and was challenged with ragweed 30 min after administration of ICI 204,219 until the forced expiratory volume in 1 s (FEV1) decreased by 20 percent or the maximum allergen concentration (100 micrograms/ml) was reached. The majority of subjects tolerated 100 micrograms/ml of allergen without a 20 percent decrease in FEV1. Inhalation formulations of ICI 204,219 successfully inhibited bronchoconstriction in subjects with reproducible sensitivity to ragweed challenges.

Topics: Administration, Inhalation; Adult; Allergens; Antigens; Asthma; Bronchial Provocation Tests; Bronchoconstriction; Female; Forced Expiratory Volume; Humans; Indoles; Leukotriene D4; Male; Phenylcarbamates; Pollen; Reproducibility of Results; Sulfonamides; Tosyl Compounds; Vital Capacity

The peptide-leukotriene antagonist, ICI 204,219 [4-(5-cyclopentyloxycarbonylamino-lmethylindol-3-ylmethyl )-3-methoxy-n-o-tolylsulfonyl benzamide], was administered 12 hours before an inhaled leukotriene D4 (LTD4) challenge during a double-blind, placebo-controlled, randomized, two-period crossover trial. Subjects with mild asthma were randomized into five treatment groups (six subjects each) and received single oral doses of placebo and either 5, 10, 20, 40, or 100 mg of ICI 204,219 on day 1 of each treatment period. ICI 204,219 was tolerated well by all subjects. A progressive dose response was observed for doses of ICI 204,219 from 5 mg through 100 mg. Compared with placebo, ICI 204,219 increased the concentration (PC20FEV1) and dose of LTD4 needed to reduce forced expiratory volume in 1 second (FEV1) by 20%. Mean LTD4 PC20FEV1 for groups that received placebo and 10, 40, or 100 mg ICI 204,219 increased by tenfold or more (p < 0.05). An association was found between the plasma concentration and protective effect of ICI 204,219 (p < 0.01). ICI 204,219 is the first leukotriene receptor antagonist for which a relationship has been established between drug plasma levels and its protective effect in subjects with asthma.

Topics: Adolescent; Adult; Analysis of Variance; Asthma; Bronchial Provocation Tests; Bronchoconstriction; Dose-Response Relationship, Drug; Double-Blind Method; Forced Expiratory Volume; Humans; Indoles; Leukotriene D4; Male; Middle Aged; Phenylcarbamates; Sulfonamides; Tosyl Compounds

Exposure to cigarette smoke complicates the treatment and management of asthma through a variety of inflammatory effects. This study aimed to investigate the differences between newly diagnosed cases of asthma in smokers and nonsmokers in terms of localized and systemic biomarkers following treatment with inhaled corticosteroids (ICS) or ICS in combination with a long-acting β2 agonist (LABA).. Specimens of exhaled breath condensate (EBC) from newly diagnosed patients with asthma were used to quantify inflammation in the airways, while blood samples were used to assess systemic inflammation. In both samples, the levels of IL-6, LTB4, LTD4, and 8-isoprostane were measured and these were repeated after 3 months of treatment with ICS or ICS + LABA.. Monitoring the alterations in 8-isoprostane levels in EBC in patients with asthma who smoke may be helpful in deciding on therapeutic management and switching treatments. Asthma control was better in nonsmokers than in smokers.

Topics: Adrenal Cortex Hormones; Asthma; Biomarkers; Breath Tests; Exhalation; Humans; Inflammation; Interleukin-6; Leukotriene B4; Leukotriene D4; Smoking

Cysteinyl leukotrienes (CysLTs), a group of inflammatory lipid mediators, are found elevated in obese-asthmatic patients. Leukotriene D. Primary human small airway epithelial cells (SAECs) were stimulated with different concentrations of LTD

Topics: Airway Remodeling; Allergens; Animals; Asthma; Bronchoalveolar Lavage Fluid; Cells, Cultured; Cytokines; Epithelial Cells; Humans; Inflammasomes; Inflammation; Leukocyte Count; Leukotriene D4; Male; Mice, Inbred BALB C; Mucin 5AC; NLR Family, Pyrin Domain-Containing 3 Protein; Obesity; Ovalbumin; Smad2 Protein; Smad3 Protein; Vimentin

The 3 cysteinyl leukotrienes (cysLTs), leukotriene (LT) C. We sought to determine whether LTD. We used 2 different in vivo models of CysLT. LTC. The conversion of LTC

Topics: Animals; Asthma; Blood Platelets; Cysteine; Cytokines; Leukotriene C4; Leukotriene D4; Leukotriene E4; Leukotrienes; Lung; Male; Mice; Mice, Inbred C57BL; Platelet Activation; Pulmonary Eosinophilia; Receptors, Leukotriene

The expression and functional role of CysLT2 receptors in asthma have not been clarified. In this study, we evaluated CysLT2 receptors expression, and effects of CysLT2-and CysLT1/2-receptor antagonists on antigen-induced bronchoconstriction using isolated lung tissues from both asthma and non-asthma subjects.. CysLT1 and CysLT2 receptors expression in asthma and non-asthma lung tissue preparations was examined in immunohistochemistry experiments, and their functional roles in antigen-induced bronchoconstriction were assessed using ONO-6950, a dual CysLT1/2-receptor antagonist, montelukast, a CysLT1 receptor antagonist, and BayCysLT2RA, a CysLT2 receptor-specific antagonist.. CysLT1 receptors were expressed on the bronchial smooth muscle and epithelium, and on alveolar leukocytes in 5 in 5 non-asthma subjects and 2 in 2 asthma subjects. On the other hand, although degrees of CysLT2 receptors expression were variable among the 5 non-asthma subjects, the expression in the asthma lung was detected on bronchial smooth muscle, epithelium and alveolar leukocytes in 2 in 2 asthma subjects. In the non-asthma specimens, antagonism of CysLT2 receptors did not affect antigen-induced bronchial contractions, even after pretreatment with the CysLT1-receptor specific antagonist, montelukast. However, in the bronchus isolated from one of the 2 asthma subjects, antagonism of CysLT2 receptors suppressed contractions, and dual antagonism of CysLT1 and CysLT2 receptors resulted in additive inhibitory effect on anaphylactic contractions.. CysLT2 receptors were expressed in lung specimens isolated from asthma subjects. Activation of CysLT2 receptors may contribute to antigen-induced bronchoconstriction in certain asthma population.

Topics: Aged; Antigens; Asthma; Bronchoconstriction; Calcium; Female; Gene Expression; Humans; Immunohistochemistry; Leukocyte Count; Leukotriene Antagonists; Leukotriene D4; Lung; Male; Middle Aged; Muscle Contraction; Muscle, Smooth; Receptors, Leukotriene; Respiratory Function Tests

Cysteinyl leukotrienes (LTs) are key mediators in inflammation. To explore the structure of the antigen-recognition site of a monoclonal antibody against LTC4 (mAbLTC), we previously isolated full-length cDNAs for heavy and light chains of the antibody and prepared a single-chain antibody comprising variable regions of these two chains (scFvLTC).. We examined whether mAbLTC and scFvLTC neutralized the biological activities of LTC4 and LTD4 by competing their binding to their receptors.. mAbLTC and scFvLTC inhibited their binding of LTC4 or LTD4 to CysLT1 receptor (CysLT1R) and CysLT2 receptor (CysLT2R) overexpressed in Chinese hamster ovary cells. The induction by LTD4 of monocyte chemoattractant protein-1 and interleukin-8 mRNAs in human monocytic leukemia THP-1 cells expressing CysLT1R was dose-dependently suppressed not only by mAbLTC but also by scFvLTC. LTC4- and LTD4-induced aggregation of mouse platelets expressing CysLT2R was dose-dependently suppressed by either mAbLTC or scFvLTC. Administration of mAbLTC reduced pulmonary eosinophil infiltration and goblet cell hyperplasia observed in a murine model of asthma. Furthermore, mAbLTC bound to CysLT2R antagonists but not to CysLT1R antagonists.. These results indicate that mAbLTC and scFvLTC neutralize the biological activities of LTs by competing their binding to CysLT1R and CysLT2R. Furthermore, the binding of cysteinyl LT receptor antagonists to mAbLTC suggests the structural resemblance of the LT-recognition site of the antibody to that of these receptors.. mAbLTC can be used in the treatment of inflammatory diseases such as asthma.

Topics: Animals; Antibodies, Monoclonal; Asthma; CHO Cells; Cricetinae; Cricetulus; Cytokines; Humans; Leukotriene Antagonists; Leukotriene C4; Leukotriene D4; Male; Mice; Mice, Inbred C57BL; Platelet Aggregation; Receptors, Leukotriene; Single-Chain Antibodies

The impact of air pollution on the respiratory system has been estimated on the basis of respiratory symptoms and lung function. However; few studies have compared lung inflammation in healthy and asthmatics children exposed to high levels of air pollution. The aim of the study was to elucidate the modulatory effect of air pollution on Cysteinyl-leukotrienes (Cys-LTs) levels in exhaled breath condensate (EBC) among healthy and asthmatic children.. We performed a cross-sectional comparative study. Children between 7-12 years of age, asthmatics and non-asthmatics, residents of a city with high levels of PM10 were included. In all cases, forced spirometry, Cys-LTs levels in EBC, and the International Study of Asthma and Allergies in Childhood questionnaire were evaluated. We also obtained average of PM10, CO, SO2 and O3 levels during the period of the study by the State Institute of Ecology.. We studied 103 children (51 asthmatics and 52 non-asthmatics). Cys-LTs levels were higher in asthmatics than in non-asthmatics (77.3 ± 21.6 versus 60.3 ± 26.8 pg/ml; p = 0.0005). Also, Cys-LTs levels in children with intermittent asthma were lower than in children with persistent asthma (60.4 ± 20.4 versus 84.7 ± 19.2 pg/ml; p = 0.0001). In the multiple regression model, factors associated with levels of Cys-LTs were passive smoking (β = 13.1, p 0.04) and to be asthmatic (β = 11.5, p 0.03).. Cys-LTs levels are higher in asthmatic children than in healthy children in a contaminated city and its levels are also associated with passive smoking.

Topics: Air Pollution; Asthma; Breath Tests; Child; Cross-Sectional Studies; Female; Forced Expiratory Volume; Healthy Volunteers; Humans; Inflammation Mediators; Leukotriene C4; Leukotriene D4; Leukotriene E4; Male; Particulate Matter; Pneumonia; Spirometry; Surveys and Questionnaires; Tobacco Smoke Pollution; Urban Population; Vital Capacity

Airway obstruction after antigen challenge is not always observed in patients with allergic asthma, even if they develop hyperresponsiveness. A similar event is observed in our guinea pig model of allergic asthma. Our aim was to study this phenomenon.. Sensitized guinea pigs were challenged with ovalbumin (OVA) 3 times every 10 days. Animals were divided into 2 groups: (1) Guinea pigs exhibiting airway obstruction after antigen challenge (R = responders), and (2) guinea pigs lacking airway obstruction response (NR = nonresponders). After the third antigen challenge, antigen-induced airway hyperresponsiveness (AI-AHR), serum OVA-specific immunoglobulins, bronchoalveolar lavage fluid (BALF) inflammatory cells, histamine, cysteinyl leukotrienes and thromboxane A2 (TxA2) BALF levels, and in vitro tracheal contraction induced by contractile mediators and OVA were evaluated.. R group consistently displayed a transient antigen-induced airway obstruction (AI-AO) as well as AI-AHR, high T×A2, histamine, OVA-IgG1, OVA-IgE and OVA-IgA levels, and intense granulocyte infiltration. NR group displayed no AI-AO and no changes in BALF measurements; nevertheless, AI-AHR and elevated OVA-IgG1 and OVA-IgA levels were observed. In all groups, histamine, TxA2 and leukotriene D4 induced a similar contraction. Tracheal OVA-induced contraction was observed only in R group. AI-AHR magnitude showed a direct association with OVA-IgG1 and OVA-IgA levels. The extent of AI-AO correlated directly with OVA-IgE and inversely with OVA-IgA levels.. Our data suggest that TxA2 and histamine participate in AI-AO likely through an IgE mechanism. AI-AHR might occur independently of AI-AO, contractile mediators release, and airway inflammatory cell infiltration, but IgA and IgG1 seem to be involved.

Topics: Airway Obstruction; Animals; Antigens; Asthma; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Guinea Pigs; Histamine; Humans; Immunization; Immunoglobulins; Leukotriene D4; Male; Ovalbumin; Respiratory Hypersensitivity; Thromboxane A2

Although respiratory viral infections cause acute exacerbations of asthma, the inflammatory responses vary depending on the causative virus. The purpose of this study was to compare the inflammatory responses in the airways of acute exacerbations of asthma induced by respiratory syncytial virus (RSV) and influenza A virus.. Sputum induction was performed in asthmatic patients with acute exacerbations induced by RSV (n = 6), influenza A (n = 7), and non-upper respiratory infection (URI)-related factors (n = 8). Sputum concentrations of cysteinyl leukotrienes (cysLTs), TNF-α and IFN-γ were measured.. Sputum cysLTs were significantly higher in RSV-induced exacerbations than in influenza A- and non-URI-induced exacerbations. Sputum TNF-α was significantly higher in influenza A-induced exacerbations than in RSV- and non-URI-induced exacerbations. Sputum IFN-γ was significantly lower in RSV-induced exacerbations than in the others.. RSV and influenza A cause acute exacerbations and have different effects on airway inflammation in asthmatic patients. RSV significantly increased cysLTs, while influenza A significantly increased TNF-α in the airway. The underlying mechanism in virus-induced asthma might depend on the viral species.

Topics: Adult; Asthma; Disease Progression; Female; Humans; Influenza A virus; Influenza, Human; Interferon-gamma; Leukotriene D4; Male; Middle Aged; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Sputum; Tumor Necrosis Factor-alpha

The value of impulse oscillometry (IOS) for bronchial provocation testing is poorly defined. We investigated the positive threshold derived from the parameters and diagnostic power of IOS for asthma with the leukotriene D(4) bronchial provocation test.. We enrolled 62 subjects with asthma and 21 healthy subjects. IOS was employed to perform the leukotriene D(4) bronchial provocation test, followed by spirometry. The positive threshold was determined based on the cutoff point in the receiver operating characteristic curve, from which the parameters with the highest diagnostic power were obtained.. Airway impedance at 5 Hz (Z(5)), resistance at 5 Hz (R(5)), and resonance frequency had the highest diagnostic power (areas under curve 0.82, 0.82, and 0.81, respectively), with increases of 57%, 43%, and 63%, corresponding to a 20% decrease in FEV(1), respectively. IOS indices yielded assay sensitivity and specificity similar to that of spirometry. The positive threshold for IOS, defined as either a 57% increase in Z(5) or a 63% increase in resonance frequency in the bronchial provocation test, yielded an assay accuracy of 0.6 in subjects with asthma.. IOS during the leukotriene D(4) bronchial provocation test has a diagnostic power similar to that of spirometry. Either a 57% increase in Z(5) or a 63% increase in resonance frequency may be regarded as a surrogate of FEV(1) decrease to determine airway hyper-responsiveness in asthma.

Topics: Adult; Airway Resistance; Area Under Curve; Asthma; Bronchial Provocation Tests; Bronchoconstrictor Agents; Comparative Effectiveness Research; Electric Impedance; Female; Humans; Leukotriene D4; Male; Middle Aged; Oscillometry; Predictive Value of Tests; ROC Curve; Spirometry

Cysteinyl leukotrienes (CysLTs) are among important inflammatory mediators in asthma pathogenesis. In this study, we aimed to determine leukotriene D₄ (LTD₄) and leukotriene E₄ (LTE₄) levels in exhaled breath condensate (EBC) in asthmatics and to evaluate the effect of smoking upon CysLTs levels and to speculate the importance of adding leukotriene receptor antagonists in smoking asthmatics.. A total of 88 participants were included in the study. Of them, 59 were asthmatics; 30 of the 59 asthmatics were smokers (Group I) and the others were non-smokers (Group II). As a control group (Group III), 29 healthy non-smokers were enrolled. EBC samples were collected (EcoScreen, Jaeger, Hoechberg, Germany) and pulmonary function tests (PFTs) were performed in each case, and an asthma control questionnaire (ACQ) was completed by the asthmatics. LTD₄ and LTE₄ levels in EBC samples were analyzed by using ELISA.. LTD₄ levels were found to be higher in Group I than other groups and similar in Group II and Group III. LTE₄ levels were lower in Group III than other groups and similar in Group I and Group II. PFTs were different between Group I and Group III and there was a significant negative correlation between LTE₄ levels and forced expiratory volume in one second and forced vital capacity ratio in Group I.. LTD₄, but not LTE₄, concentrations in EBC were higher in asthmatic smokers than asthmatic nonsmokers. LTE₄ concentrations in EBC were higher in asthmatics than healthy non-smokers. In smoking asthmatics usage of agents that block the effects of LTD₄ can be beneficial; however, new clinical studies are required.

Topics: Adult; Asthma; Breath Tests; Case-Control Studies; Clinical Chemistry Tests; Cysteine; Enzyme-Linked Immunosorbent Assay; Exhalation; Female; Humans; Leukotriene Antagonists; Leukotriene D4; Leukotrienes; Male; Middle Aged; Receptors, Leukotriene; Respiratory Function Tests; Smoking; Surveys and Questionnaires; Young Adult

Previous studies showed that heparin's anti-allergic activity is molecular weight dependent and resides in oligosaccharide fractions of <2500 daltons.. To investigate the structural sequence of heparin's anti-allergic domain, we used nitrous acid depolymerization of porcine heparin to prepare an oligosaccharide, and then fractionated it into disaccharide, tetrasaccharide, hexasaccharide, and octasaccharide fractions. The anti-allergic activity of each oligosaccharide fraction was tested in allergic sheep.. Allergic sheep without (acute responder) and with late airway responses (LAR; dual responder) were challenged with Ascaris suum antigen with and without inhaled oligosaccharide pretreatment and the effects on specific lung resistance and airway hyperresponsiveness (AHR) to carbachol determined. Additional inflammatory cell recruitment studies were performed in immunized ovalbumin-challenged BALB/C mice with and without treatment.. The inhaled tetrasaccharide fraction was the minimal effective chain length to show anti-allergic activity. This fraction showed activity in both groups of sheep; it was also effective in inhibiting LAR and AHR, when administered after the antigen challenge. Tetrasaccharide failed to modify the bronchoconstrictor responses to airway smooth muscle agonists (histamine, carbachol and LTD4), and had no effect on antigen-induced histamine release in bronchoalveolar lavage fluid in sheep. In mice, inhaled tetrasaccharide also attenuated the ovalbumin-induced peribronchial inflammatory response and eosinophil influx in the bronchoalveolar lavage fluid. Chemical analysis identified the active structure to be a pentasulfated tetrasaccharide ([IdoU2S (1→4)GlcNS6S (1→4) IdoU2S (1→4) AMan-6S]) which lacked anti-coagulant activity.. These results demonstrate that heparin tetrasaccharide possesses potent anti-allergic and anti-inflammatory properties, and that the domains responsible for anti-allergic and anti-coagulant activity are distinctly different.

Topics: Animals; Anti-Asthmatic Agents; Anticoagulants; Antigens, Helminth; Ascaris suum; Asthma; Bronchoalveolar Lavage Fluid; Carbachol; Carbohydrate Sequence; Female; Heparin; Histamine; Histamine Release; Leukotriene D4; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Oligosaccharides; Sheep

Airway epithelial cells play a central role in the physiopathology of asthma. They release eotaxins when treated with T(H)2 cytokines such as interleukin (IL)-4 or IL-13, and these chemokines attract eosinophils and potentiate the biosynthesis of cysteinyl leukotrienes (cysLTs), which in turn induce bronchoconstriction and mucus secretion. These effects of cysLTs mainly mediated by CysLT(1) and CysLT(2) receptors on epithelial cell functions remain largely undefined. Because the release of inflammatory cytokines, eotaxins, and cysLTs occur relatively at the same time and location in the lung tissue, we hypothesized that they regulate inflammation cooperatively rather than redundantly. We therefore investigated whether cysLTs and the T(H)2 cytokines would act in concert to augment the release of eotaxins by airway epithelial cells.. A549 cells or human primary bronchial epithelial cells were incubated with or without IL-4, IL-13, and/or LTD(4). The release of eotaxin-3 and the expression of cysLT receptors were assessed by ELISA, RT-PCR, and flow cytometry, respectively.. IL-4 and IL-13 induced the release of eotaxin-3 by airway epithelial cells. LTD(4) weakly induced the release of eotaxin-3 but clearly potentiated the IL-13-induced eotaxin-3 release. LTD(4) had no effect on IL-4-stimulated cells. Epithelial cells expressed CysLT(1) but not CysLT(2). CysLT(1) expression was increased by IL-13 but not by IL-4 and/or LTD(4). Importantly, the upregulation of CysLT(1) by IL-13 preceded eotaxin-3 release.. These results demonstrate a stepwise cooperation between IL-13 and LTD(4). IL-13 upregulates CysLT(1) expression and consequently the response to cysLTs This results in an increased release of eotaxin-3 by epithelial cells which at its turn increases the recruitment of leukocytes and their biosynthesis of cysLTs. This positive amplification loop involving epithelial cells and leukocytes could be implicated in the recruitment of eosinophils observed in asthmatics.

Topics: Asthma; Bronchi; Chemokine CCL24; Chemokine CCL26; Chemokines, CC; Cysteine; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Flow Cytometry; Gene Expression Regulation; Humans; Inflammation; Interleukin-13; Interleukin-4; Kinetics; Leukotriene D4; Leukotrienes; Models, Biological; Recombinant Proteins; Th2 Cells

Lipopolysaccharides (LPS) have been associated with a protective role in the development of asthma while higher levels of endotoxin have been linked with more severe asthma. LPS recruit neutrophils and eosinophils and activate macrophages via the CD14 receptor. The soluble CD 14 receptor (sCD14) has been found in bronchoalveolar lavage fluid in different diseases including allergic asthma. To elucidate the kinetics and the regulation of sCD14 concentrations in BAL in asthma, 18 patients with allergic asthma underwent segmental allergen challenge at different time points (10 min, 18, 42 and 162 h). In addition, CD14(+) peripheral blood mononuclear cell (PBMC-CD14(+)) cultures from seven allergic and seven non-allergic subjects were stimulated with LPS, leukotrien D(4) (LTD(4)), a combination of LPS and LTD(4), IL-17 and LTD(4) in presence of the leukotriene-receptor antagonist (LTRA) Montelukast for 6, 12 and 24 h. sCD14 concentrations in BAL and the supernatants were measured by ELISA. sCD14 concentrations in BAL were significantly increased 18 h after allergen challenge and peaked at 42 h. At 162 h, concentrations had returned to baseline levels. In PBMC-CD14(+) cultures, sCD14 levels increased significantly 24 h after stimulation with LTD(4) and Montelukast was able to block LTD(4)-induced stimulation. Allergen challenge leads to a significant increase in sCD14 concentrations in BAL and might modulate the allergen-induced inflammation. In addition, LTD(4) might play a role in the release of sCD14, and it could be speculated that sCD14 reduction by LTRA might contribute to the mechanisms of LTRA in the treatment of allergic asthma.

Topics: Acetates; Adolescent; Adult; Allergens; Asthma; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Cyclopropanes; Enzyme-Linked Immunosorbent Assay; Female; Humans; Leukotriene Antagonists; Leukotriene D4; Lipopolysaccharide Receptors; Lipopolysaccharides; Male; Quinolines; Sulfides; Time; Young Adult

Eosinophils preferentially accumulate at sites of inflammation in the asthmatic airway. Participation of circulating eosinophils in the airway inflammation in asthma involves their interaction with adhesion molecules expressed on the endothelial cell surface and exposure to inflammatory mediators, such as cysteinyl leukotrienes (cysLTs).. To investigate whether interaction of eosinophils with adhesion molecules modifies the functions of these cells induced by cysLTs.. Eosinophils were isolated from the blood of healthy donors, incubated in the EIA plates coated with adhesion proteins, and then exposed to LTD4. The generation of superoxide anion (O2-), adhesion to the plates, and release of eosinophil-derived neutrotoxin (EDN) were evaluated.. Neither VCAM-1 nor LTD4 (100 nM) independently induced eosinophil O2- generation, however, combined exposure to the two molecules synergistically induced eosinophil O2- generation. ICAM-1 by itself induced eosinophil O2- generation, which was enhanced by LTD4. On the contrary, P-selectin did not induce O2- generation, either in the presence or absence of LTD4. LTD4 significantly enhanced eosinophil adhesion to rh-VCAM-1 and rh-ICAM-1, but not to rh-P-selectin. Finally, we observed that combined exposure of eosinophils to LTD4 and VCAM-1 induced the release of EDN.. Combined exposure to VCAM-1 or ICAM-1 and cysLT effectively induces the effector functions of eosinophils. Eosinophil adhesion to and migration across endothelial cells via these specific adhesion proteins and subsequent exposure to cysLTs may be mechanisms underlying activation of the effector functions of eosinophils in the asthmatic airway.

Topics: Asthma; Cell Adhesion; Cells, Cultured; Eosinophil-Derived Neurotoxin; Eosinophils; Humans; Intercellular Adhesion Molecule-1; Leukotriene D4; Superoxides; Up-Regulation; Vascular Cell Adhesion Molecule-1

To investigate the effect of montelukast (MK) on airway inflammation and remodeling in asthmatic rats, and to explore the regulating role of MK on vascular endothelial growth factor (VEGF) and its receptors.. Twenty-four male Sprague-Dawley rats were randomly divided into 3 groups, a control group (n = 8), an asthmatic group (n = 8) and a MK treated group (n = 8). The rats were sensitized with ovalbumin and AL (OH3), and repeatedly exposed to aerosolized ovalbumin. Airway reactivity of the animals were measured by animal lung function meter. VEGF levels and leukotriene D(4) (LTD(4)) in serum were measured by enzyme linked-immunosorbent assay (ELISA). The pathologic changes of bronchi and the lung tissue were evaluated, and the expression of VEGF and its acceptors was analyzed with immunohistochemistry. The vascular counts and vascular smooth muscle thickness were measured by using image analysis system.. The bronchial provocation test showed that, in the asthmatic group, the average expiratory resistance increased remarkably. The serum levels of VEGF and LTD(4) in the asthmatic group were 31 +/- 6 and 11 +/- 4 respectively, significantly higher than those in the control group (17 +/- 5 and 6.1 +/- 0.7) respectively and in the MK group (15 +/- 4 and 9.8 +/- 1.6) respectively. (F 63.78, 39.56 all P < 0.01). Immunohistochemistry showed that, the expression of VEGF, VEGFR(1) and VEGFR(2) in the asthmatic group were increased, as compared to those in the control group and the treated group. The vascular counts were 14 +/- 2, 22 +/- 2 and 16 +/- 4 in the control, the asthmatic, and the treated groups.. VEGF and its receptors were over-expressed in the sensitized rat model, and involved in angiogenesis and airway remodeling. MK may be effective in reducing allergic airway inflammation and airway remodeling through VEGF and VEGFR.

Topics: Acetates; Airway Remodeling; Animals; Asthma; Cyclopropanes; Leukotriene Antagonists; Leukotriene D4; Male; Neovascularization, Pathologic; Quinolines; Rats; Rats, Sprague-Dawley; Receptors, Vascular Endothelial Growth Factor; Sulfides; Vascular Endothelial Growth Factor A

We evaluated the effects of NT-702 (parogrelil hydrochloride, NM-702, 4-bromo-6-[3-(4-chlorophenyl) propoxy]-5-[(pyridine-3-ylmethyl) amino] pyridazin-3(2H)-one hydrochloride), a selective phosphodiesterase 3 inhibitor, on the asthmatic response in guinea pigs. NT-702 at a concentration of 1 x 10(-7)M elevated the cyclic adenosine monophosphate content in prostaglandin E(2)-treated guinea pig tracheal smooth muscle cells. Leukotriene (LT) D(4)- and histamine-induced contraction of isolated guinea pig tracheal strips was inhibited by NT-702, with EC(50) values of 3.2 x 10(-7) and 2.5 x 10(-7)M, respectively. In an in vivo study, NT-702 suppressed LTD(4)-induced bronchoconstriction and the ovalbumin-induced immediate asthmatic response in guinea pigs through its bronchodilating effect. Furthermore, NT-702 also suppressed the ovalbumin-induced late asthmatic response, airway hyperresponsiveness, and the accumulation of inflammatory cells in the bronchoalveolar lavage fluid. These results suggest that NT-702 has an anti-inflammatory effect as well as a bronchodilating effect and might be useful as a novel potent therapeutic agent for the treatment of bronchial asthma, a new type of agent with both a bronchodilating and an anti-inflammatory effect.

Topics: Animals; Anti-Inflammatory Agents; Antigens; Asthma; Bronchoconstriction; Bronchodilator Agents; Cell Movement; Cyclic AMP; Dinoprostone; Enzyme Inhibitors; Guinea Pigs; Histamine; In Vitro Techniques; Leukotriene D4; Lung; Male; Muscle Contraction; Muscle, Smooth; Phosphodiesterase 3 Inhibitors; Pyridazines; Trachea

Oral cysteinyl-leukotriene (LT) receptor antagonists such as montelukast are used for reducing airway inflammation and exacerbations. However, inhaled therapy using LT receptor antagonists has not been studied. In the present study, the effect of inhaled montelukast was investigated on airway hyperresponsiveness measured by cysteinyl-LT induced bronchoconstriction in an animal model of asthma. Bronchoconstriction responses were induced by inhaled LTC4 and LTD4 (0.2 microg/ml each) or three doses of intravenous LTC4 and LTD4 (0.3, 1, 3 microg/kg) in ovalbumin (OVA)-sensitized Hartley male guinea-pigs. The response was measured by the change in peak pressure of airway opening (Pao). The effect of montelukast was evaluated by the comparison of bronchoconstriction responses between the groups of animals pre-treated with 15-min inhalation of 10mg/ml montelukast and saline. To evaluate the tissue injury which might be caused by montelukast inhalation, lung tissues were examined for the histology. The broncoconstriction responses induced by inhaled LTC4 and LTD4 were enhanced by OVA sensitization in the guinea-pigs. In sensitized animals, the significant increases in peak Pao were 18.5+/-2.1 cmH(2)O by LTC4 inhalation and 25.0+/-1.6 cmH(2)O by LTD4 inhalation on average. Prior treatment of inhaled montelukast potently suppressed the peak Pao increases induced by both inhaled and intravenous LTC4 and LTD4 (all P<0.01 vs. saline control). Moreover, the suppression of inhaled montelukast against LTD4-induced bronchoconstriction was observed for at least up to 24h. According to the histological examination, montelukast inhalation produced no injury to the lung tissue. Inhaled montelukast, a cysteinyl-LT receptor antagonist, was effective in inhibiting cysteinyl-LT-induced acute bronchoconstriction, and may have the potential for clinical use as a new asthma drug.

Topics: Acetates; Administration, Inhalation; Animals; Asthma; Bronchial Hyperreactivity; Bronchoconstriction; Cyclopropanes; Cysteine; Disease Models, Animal; Guinea Pigs; Immunologic Factors; Leukotriene Antagonists; Leukotriene C4; Leukotriene D4; Leukotrienes; Lung; Male; Ovalbumin; Quinolines; Sulfides

Topics: Asthma; Cell Line; Chemokine CCL2; Cysteine; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Humans; Leukotriene Antagonists; Leukotriene D4; Leukotrienes; Propionates; Quinolines; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Atopy is a well-defined immune phenotype that is reported to be a risk factor for asthma. Among the many loci that contribute to a genetic predisposition to asthma, the cysteinyl leukotriene receptor genes and their variants have been important subjects of study because they are functionally and pharmacologically implicated in the atopy phenotype affecting many asthma subjects. Moreover, the product of cysteinyl-leukotriene 1 receptor gene (CysLT1), located at Xq13.2, is targeted by LT receptor antagonists. In our earlier association study, the M201V variant of the cysteinyl-leukotriene 2 receptor gene (CysLT2), located at 13q14, was implicated in atopic asthma. Here we report the screening of the coding region of the CysLT1, gene in the highly asthmatic Tristan da Cunha population. In this population, we discovered a CysLT1 G300S variant that is carried with a significantly higher frequency in atopics and asthmatics from the Tristan da Cunha population. Furthermore, we report the asthma independent association of the CysLT1 G300S variant with atopy. Subsequently, we compared the changes conferred by each SNP on CysLT function. The CysLT1 300S receptor interacts with LTD4 with significantly greater potency. For the 300S variant, a statistically significant decrease in the effector concentration for half-maximum response (EC50) for intracellular Ca flux and total InsP generation is observed. Other aspects of the receptor function and activity, such as desensitization, pharmacologic profile in response to montelukast, and cellular localization, are unchanged. These in vitro analyses provide evidence that the 300S CysLT1 variant, found more commonly in atopics in the Tristan da Cunha population, encodes a functionally more sensitive variant.

Topics: Adult; Amino Acid Sequence; Animals; Asthma; Atlantic Islands; Base Sequence; Calcium Signaling; Chlorocebus aethiops; COS Cells; DNA Primers; Female; Gene Frequency; Genetic Variation; Humans; Hypersensitivity, Immediate; Inositol Phosphates; Male; Membrane Proteins; Molecular Sequence Data; Mutagenesis, Site-Directed; Pharmacogenetics; Phenotype; Polymorphism, Single Nucleotide; Receptors, Leukotriene; Recombinant Proteins; Sequence Homology, Amino Acid; Transfection

Cysteinyl-leukotrienes are lipid derived mediators involved in asthma. They are able to stimulate eosinophil chemotaxis in vitro. Induced sputum from asthmatics has been shown to contain eosinophil chemotactic activity. The purpose of our study was to evaluate the contribution of cysteinyl-leukotrienes to sputum eosinophil chemotactic activity in asthmatics and to seek whether there might be differences between asthmatics free of inhaled corticosteroids vs those regularly receiving this treatment.. Twenty-two patients (11 corticosteroid free, mean FEV1 99% predicted, 11 corticosteroid-treated, mean FEV1 77% predicted) recruited from our asthma clinic underwent a sputum induction. Sputum was processed according to standard procedure. Eosinophil chemotactic activity contained in the fluid phase was assessed using Boyden microchamber model and expressed as chemotaxis index (CI). Cysteinyl-leukotrienes were measured in sputum supernatant by ELISA and their role in sputum eosionophil chemotactic activity was evaluated by using montelukast, a selective antagonist of a cys-LT1 receptor.. Cysteinyl-leukotrienes were well detectable in sputum supernatants from both steroid-naive (247 +/- 42 pg/ml) and steroid-treated (228 +/- 26 pg/ml) asthmatics. Sputum eosinophil chemotactic activity was indiscriminately present in both corticosteroid-naive (CI: 2.61 +/- 0.22) and corticosteroid-treated (2.98 +/- 0.35) asthmatics. Montelukast (100 microM) significantly inhibited the eosinophil chemotactic activity in both groups achieving a mean inhibition of 54.2 +/- 9.2% (P < 0.001) and 64.7 +/- 7.8% (P < 0.001) in steroid-naive and steroid-treated asthmatics respectively.. Cysteinyl-leukotrienes actively participate in sputum eosinophil chemotactic activity found in asthmatics irrespective of whether they are or not under treatment with inhaled corticoids.

Topics: Adult; Asthma; Biomarkers; Bronchial Provocation Tests; Chemotaxis; Cohort Studies; Cysteine; Enzyme-Linked Immunosorbent Assay; Eosinophils; Female; Humans; Leukotriene D4; Leukotrienes; Male; Middle Aged; Probability; Prognosis; Risk Factors; Sensitivity and Specificity; Sputum; Steroids

Because cysteinyl-leukotrienes (cysLTs) are major protagonists in the pathophysiology of human asthma, and because neutrophils are involved in the more severe form of asthma, we studied the potential for leukotriene (LT) D(4) to induce synthesis of the chemokine IL-8 through activation of the CysLT1 receptor. We found LTD(4) to induce IL-8 gene expression in monocytic THP-1 cells and human dendritic cells with complete abrogation by selective CysLT1 antagonists. Human embryonic kidney-293 cells stably transfected with CysLT1 were used to better study the transcriptional regulation of the IL-8 promoter. Stimulation of the cells with graded concentrations of LTD(4) resulted in a time- and concentration-dependent induction of IL-8 transcription and protein synthesis. Use of IL-8 promoter mutants with substitutions in their NF-kappaB, activator protein (AP)-1, and NF-IL-6 binding elements revealed a requirement for NF-kappaB and AP-1, but not NF-IL-6, in LTD(4)-induced activation of the IL-8 promoter. Overexpression of dominant-negative IkappaBalpha inhibited the IL-8 transactivation induced by LTD(4). NF-kappaB DNA binding activity was induced by LTD(4), as determined by electrophoretic mobility shift assays, and could be supershifted by antibodies against p50 and p65. Supershift assays after LTD(4) stimulation also indicated the formation of a c-Jun/c-Fos complex. Moreover, our results demonstrate that LTD(4) upregulates the expression of c-fos and c-jun at the mRNA level. Our data show for the first time that LTD(4), via the CysLT1 receptor, can transcriptionally activate IL-8 production, with involvement of the transcription factors p50, p65, Fos, and Jun. These findings provide mechanistic and potentially therapeutic elements for modulation of the inflammatory component of asthma.

Topics: Asthma; Cell Line; Dendritic Cells; DNA; Dose-Response Relationship, Drug; Humans; Interleukin-8; Leukotriene D4; Membrane Proteins; Monocytes; Mutation; NF-kappa B p50 Subunit; Promoter Regions, Genetic; Protein Binding; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Receptors, Leukotriene; RNA, Messenger; Time Factors; Transcription Factor AP-1; Transcription, Genetic; Transfection

The response to beta2-adrenoceptor agonists is reduced in asthmatic airways. This desensitization may be in part due to inflammatory mediators and may involve cysteinyl-leukotrienes (cysteinyl-LTs). Cysteinyl-LTs are pivotal inflammatory mediators that play important roles in the pathophysiology of asthma, allergic rhinitis, and other inflammatory conditions. We tested the hypothesis that leukotriene D4 (LTD4) and allergen challenge cause beta2-adrenoceptor desensitization through the activation of protein kinase C (PKC).. The isoproterenol-induced cAMP accumulation was evaluated in human airway smooth muscle cell cultures challenged with exogenous LTD4 or the PKC activator phorbol-12-myristate-13-acetate with or without pretreatments with the PKC inhibitor GF109203X or the CysLT1R antagonist montelukast. The relaxant response to salbutamol was studied in passively sensitized human bronchial rings challenged with allergen in physiological salt solution (PSS) alone, or in the presence of either montelukast or GF109203X.. In cell cultures, both LTD4 and phorbol-12-myristate-13-acetate caused significant reductions of maximal isoproterenol-induced cAMP accumulation, which were fully prevented by montelukast and GF109203X, respectively. More importantly, GF109203X also prevented the attenuating effect of LTD4 on isoproterenol-induced cAMP accumulation. In bronchial rings, both montelukast and GF109203X prevented the rightward displacement of the concentration-response curves to salbutamol induced by allergen challenge.. LTD4 induces beta2-adrenoceptor desensitization in human airway smooth muscle cells, which is mediated through the activation of PKC. Allergen exposure of sensitized human bronchi may also cause a beta2-adrenoceptor desensitization through the involvement of the CysLT1R-PKC pathway.

Topics: Adrenergic beta-Agonists; Albuterol; Allergens; Asthma; Bronchi; Bronchodilator Agents; Cells, Cultured; Cyclic AMP; Cysteine; Dose-Response Relationship, Drug; Humans; In Vitro Techniques; Isoproterenol; Leukotriene D4; Leukotrienes; Myocytes, Smooth Muscle; Protein Kinase C; Receptors, Adrenergic, beta-2

To observe the changing contents of leukotriene B4 ( LTB4 ), leukotriene C4 ( LTC4 ), and leukotriene D4 (LTD4 ) of lung tissue in asthmatic rats, and explore the effect of Shuanglong Capsule (SLC) on it.. SD rats were randomly divided into the nomal group, asthmatic model group, Dexamethasone group and the high, middle and low dose SLC groups. All rats except those in the normal group were sensitized by ovalbumin and challenged with the antigen, and the contents of LTB4, LTC4 and LTD4 in lung tissue of all the groups were measured by reverse phase-high performance liquid chromatography (RP-HPLC) and compared.. The levels of LTB4, LTC4, and LTD4 of asthmatic rats were significantly higher than those of rats in the normal group. Dexamethasone and SLC at the dose of 8. 27 g/kg or 4. 13 g/kg could significantly inhibit the production of leukotrienes of lung tissue in asthmatic rats (P <0.05).. SLC can significantly inhibit the formation of inflammatory medium LTs of lung tissue in asthmatic rats, it may be one of the key mechanisms of SLC in anti-asthma and anti-inflammatory action.

Topics: Animals; Anti-Asthmatic Agents; Asthma; Drugs, Chinese Herbal; Leukotriene B4; Leukotriene C4; Leukotriene D4; Leukotrienes; Lung; Rats; Rats, Sprague-Dawley; Tablets

Eosinophils may play an important role in the pathogenesis of airway remodeling in asthma through the production of various fibrogenic cytokines such as transforming growth factor-beta1 (TGF-beta1). Cysteinyl leukotrienes are also suggested to be involved in remodeling with their potential to induce proliferation of airway smooth muscle cells. Since massive eosinophil infiltration and the release of cysteinyl leukotrienes in airway secretions are often seen in asthma, we hypothesized that cysteinyl leukotrienes may be involved in airway remodeling through induction of TGF-beta1 from eosinophils. Peripheral blood eosinophils were cultured with leukotriene D(4) (LTD(4)) and/or interleukin-5 (IL-5) or granulocyte colony-stimulating factor (GM-CSF) for 16 h and gene expression of TGF-beta1 was quantified with real-time PCR. A combination of LTD(4) and IL-5 or LTD(4) and GM-CSF synergistically induced TGF-beta1 expression in eosinophils although stimulation with single factor, LTD(4), IL-5 or GM-CSF did not induce the gene expression. LTD(4) also induced significant gene expression in eosinophils cultured in an intercellular adhesion molecule-1-coated plate. The results suggested that CysLTs stimulate eosinophils to induce TGF-beta1 production in allergic inflammation where IL-5 and GM-CSF are abundant and may be involved in the pathogenesis of airway remodeling.

Topics: Asthma; Eosinophils; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Interleukin-5; Leukotriene D4; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation

While clinical trials with antileukotrienes have shown overall beneficial effects in asthma, the factors that determine leukotriene dependent asthma are still unclear. A study was undertaken to determine whether or not leukotriene responsiveness in the airways correlates with endogenous leukotriene biosynthesis.. Bronchial responsiveness to leukotriene (LT) D4 was assessed as PD20FEV1 in 20 subjects with mild asthma and 10 healthy controls, and compared with bronchial responsiveness to methacholine and two global measures of leukotriene production-urinary LTE4 and ex vivo production of LTB4 in whole blood.. In patients with asthma the bronchoconstrictor activity of LTD4 was about 1300 times greater than methacholine (geometric mean PD20 0.69 nmol v 887 nmol). Those who were most responsive to LTD4 were relatively less responsive to methacholine (p<0.01). There was, however, no correlation between bronchial responsiveness to LTD4 and urinary LTE4 or blood ex vivo LTB4 levels in asthmatic subjects or healthy controls. Subjects with asthma treated with inhaled corticosteroids produced higher levels of LTB4 (p<0.05).. General measures of leukotriene production cannot predict bronchial responsiveness to LTD4. The unique bronchoconstrictive potency of LTD4 on human airways may relate to the locally regulated expression of the cysteinyl LT1 receptor.

Topics: Adult; Asthma; Biomarkers; Bronchi; Bronchoconstrictor Agents; Cross-Sectional Studies; Dose-Response Relationship, Drug; Female; Forced Expiratory Volume; Humans; Ionophores; Leukotriene D4; Leukotrienes; Male; Methacholine Chloride

Argemone platyceras is used in Mexico as a remedy for cough, bronchitis and pneumonia. The present study was performed to investigate the pharmacological anti-asthmatic properties of Argemone platyceras on airways and to identify its active principles. Methanol extracts of leaves and flowers, subsequent organic and aqueous extraction phases, and silica gel chromatography fractions were assayed on the carbachol-induced response, and/or on ovalbumin antigenic challenge, and on leukotriene D(4)-induced response of tracheae from sensitized and non-sensitized guinea-pigs. Methanol extracts, ethyl-acetate phase, and its fractions 6 and 7 inhibited the carbachol-induced contractile response. Isoquercitrin and rutin were the main compounds found in fractions 6 and 7 respectively. Isoquercitrin (fraction 6) abolished the response to ovalbumin, and decreased the contractile response to leukotriene D(4). Because of its effect on carbachol-induced contractile response, on the late-phase response to ovalbumin, and on leukotriene D(4)-induced contractile response, isoquercitrin might be highly useful in treatment of asthma.

Topics: Acetates; Animals; Anti-Asthmatic Agents; Anti-Inflammatory Agents, Non-Steroidal; Argemone; Asthma; Bronchoconstriction; Carbachol; Chemical Fractionation; Dose-Response Relationship, Drug; Flowers; Guinea Pigs; Indomethacin; Leukotriene D4; Magnetic Resonance Spectroscopy; Male; Methanol; Molecular Structure; Muscle Contraction; Ovalbumin; Phytotherapy; Plant Leaves; Quercetin; Rutin; Time Factors; Trachea

Viral respiratory tract infections represent the most frequent cause of asthma exacerbation in both children and adults, but the precise mechanism of such exacerbation remains unknown.. To determine the critical mediator of naturally occurring parainfluenza virus (PIV) 3-induced mild asthma exacerbations in adults.. The study subjects were 19 adult asthmatics with mild asthma exacerbation (peak expiratory flow = 60-80% of predicted before bronchodilator use and >80% of predicted after initial bronchodilator treatment). Differential cell counts and concentrations of inflammatory markers including eosinophil cationic protein (ECP), cysteinyl leukotrienes (cysLTs), interleukin (IL)-5, IL-10 and IL-12 were measured in the induced sputum obtained from adults with PIV3- (n = 9) and non-cold-induced (n = 10) exacerbation of asthma during both acute and convalescent phases.. PIV3 infection was confirmed by the presence of viral RNA in nasopharyngeal aspirates. Mild exacerbation of asthma was not associated with significant changes in sputum differential cell counts. Concentrations of sputum ECP and cytokines were comparable between PIV3 and non-cold-induced patients. In contrast, PIV3 infection was associated with a significant increase in sputum cysLTs during the acute phase of mild asthma exacerbation.. Our results identified cysLTs as a critical mediator of PIV3-induced acute asthma exacerbation.

Topics: Adult; Asthma; Cytokines; Eosinophil Cationic Protein; Female; Humans; Leukocytes; Leukotriene D4; Male; Middle Aged; Parainfluenza Virus 3, Human; Recurrence; Respirovirus Infections; Sputum

Topics: Anti-Asthmatic Agents; Asthma; Chemical and Drug Induced Liver Injury; Drug Interactions; Humans; Indoles; Leukotriene D4; Phenylcarbamates; Sulfonamides; Tosyl Compounds

Cysteinyl leukotrienes (CYSLTR) are potent biological mediators in the pathophysiology of asthma for which two receptors have been characterized, CYSLTR1 and CYSLTR2. The leukotriene modifying agents currently used to control bronchoconstriction and inflammation in asthmatic patients are CYSLTR1-specific leukotriene receptor antagonists. In this report, we investigated a possible role for therapeutic modulation of CYSLTR2 in asthma by investigating genetic association with asthma and further characterization of the pharmacology of a coding polymorphism.. The association of CYSLTR2 polymorphisms with asthma was assessed by transmission disequilibrium test in two family-based collections (359 families from Denmark and Minnesota, USA and 384 families from the Genetics of Asthma International Network).. A significant association of the coding polymorphism, 601A>G, with asthma was observed (P = 0.003). We replicated these findings in a collection of 384 families from the Genetics of Asthma International Network (P = 0.04). The G allele is significantly under-transmitted to asthmatics, indicating a possible role for this receptor in resistance to asthma. The potency of cysteinyl leukotrienes at the wild-type CYSLTR2 and the coding polymorphism 601A>G were assessed using a calcium mobilization assay. The potency of LTC4 and LTE4 was similar for both forms of the receptor and LTB4 was inactive, however, LTD4 was approximately five-fold less potent on 601A>G compared to wild-type CYSLTR2.. Since 601A>G alters the potency of LTD4 and this variant allele may be associated with resistance to asthma, it is possible that modulation of the CYSLTR2 may be useful in asthma pharmacotherapy.

Topics: Adolescent; Adult; Alleles; Asthma; Cell Line; Child; Child, Preschool; Cloning, Molecular; Family Health; Genetic Variation; Genotype; Humans; Leukotriene D4; Leukotrienes; Linkage Disequilibrium; Membrane Proteins; Middle Aged; Phenotype; Polymorphism, Genetic; Receptors, Leukotriene

It has been demonstrated that both cysteinyl leukotrienes (cysLTs) and cytokines are involved in the pathophysiology of bronchial asthma. Nonetheless, the exact mechanism involved in the interaction between these 2 molecules has yet to be determined.. The aim of the present study was to determine the effects of cysLTs on allergic airway inflammation and allergen-specific cytokine production in a murine model of asthma.. Four groups of BALB/c mice (control mice, Dermatophagoides farinae allergen-sensitized mice, pranlukast cysLT receptor antagonist-treated allergen-sensitized mice, and dexamethasone-treated allergen-sensitized mice) were examined.. Allergen-sensitized mice exhibited increased airway responsiveness and inflammation. Pranlukast-treated mice showed significant attenuation of these changes concomitant with reduction of T(H)2 cytokine and IFN-gamma production by isolated lung mononuclear cells (MNCs). A much stronger inhibition of all cytokines was noted in dexamethasone-treated mice. Pranlukast also significantly inhibited production of RANTES and activation of nuclear factor kappa B (NF-kappa B) in the isolated lung MNCs. Leukotriene D(4) stimulated isolated lung MNCs to produce RANTES but not any other cytokines and also activated NF-kappa B in these cells.. Our results suggest that cysLTs activate NF-kappa B and induce RANTES production from isolated lung MNCs, which in turn might cause migration of eosinophils and activated T lymphocytes into the airway.

Topics: Animals; Antigens, Dermatophagoides; Asthma; Bronchial Hyperreactivity; Bronchitis; Chemokine CCL5; Chromones; Cysteine; Cytokines; Female; Inflammation Mediators; Leukotriene Antagonists; Leukotriene D4; Leukotrienes; Lung; Mice; Mice, Inbred BALB C; Monocytes; NF-kappa B; Transcription Factor RelA

Leukotrienes (LTs) are important in asthma, and LT modifiers modulate antigen-induced asthma. Overproduction of LT by suppression of cyclooxygenase activity is involved in patients with aspirin-intolerant asthma (AIA).. House dust mite (HDM) inhalation provocation tests were performed in HDM-sensitive asthmatic inpatients without AIA (HDM group; n = 6), and aspirin oral provocation tests were performed in AIA patients (ASA group; n = 7). Tests were repeated using the same regimen after 7 days of treatment with pranlukast, an LT receptor antagonist (LTRA). The effects of pranlukast on changes in sputum LTC(4)-LTD(4), eosinophil cationic protein (ECP), eosinophil count, urinary LTE(4)/creatinine, 11-dehydrothromboxane B(2) (11-dhTXB(2))/creatinine, serum LTC(4)-LTD(4), ECP, and peripheral blood eosinophil count, during immediate asthmatic reaction (IAR) and late asthmatic reaction (LAR) in the HDM group and during IAR in the ASA group for each test, were compared in each group.. In the HDM group, IAR and LAR were observed. Sputum LTC(4)-LTD(4) and urinary LTE(4)/creatinine increased significantly both during IAR and LAR. Sputum ECP increased during IAR and further increased during LAR. Eosinophil count in the sputum did not increase during IAR but significantly increased during LAR. Pranlukast suppressed the fall in FEV(1) both during IAR and LAR (73.8% and 51.9%, respectively) and inhibited the increase in sputum eosinophil count during LAR and sputum ECP during IAR and LAR. In the ASA group, aspirin-induced IAR was associated with a fall in urinary 11-dhTXB(2)/creatinine, increased the levels of sputum LTC(4)-LTD(4) and ECP and urinary LTE(4)/creatinine. Pranlukast suppressed IAR and inhibited the increase of the level of sputum ECP, but failed to change aspirin-induced LT production in the sputum and urine. The levels of sputum LTC(4)-LTD(4) and urinary LTE(4)/creatinine in the stable phase in the ASA group were significantly greater than those in the HDM group.. Our results indicated that HDM-provoked asthma is associated with overproduction of LT with an antigen-antibody reaction, while AIA is associated with overproduction of LT with a shift to the 5-lipoxygenase series of the arachidonate cascade. LTRA may be useful against both types of asthma through inhibition of LT activity and eosinophilic inflammation of the airways.

Topics: Adult; Anti-Asthmatic Agents; Aspirin; Asthma; Blood Proteins; Bronchial Provocation Tests; Chromones; Drug Hypersensitivity; Eosinophil Granule Proteins; Eosinophils; Female; Forced Expiratory Volume; Humans; Leukocyte Count; Leukotriene D4; Leukotriene E4; Male; Middle Aged; Ribonucleases; Thromboxane B2

Airway obstruction, hyperresponsiveness, and the accumulation and persistence within the airways of inflammatory cells characterize asthma. Interleukin (IL)-3, granulocyte macrophage colony- stimulating factor (GM-CSF), and IL-5 are among several cytokines that have been shown to be increased in asthma and to contribute to atopic inflammation. They mediate their effect via receptors that have a common beta subunit (beta(c)). We hypothesized that blocking of this common beta(c) would impair the airway response to antigen. We report that an antisense (AS) phosphorothioate oligodeoxynucleotide (ODN) found to specifically inhibit transcription of the beta(c) in rat bone marrow cells also caused inhibition of beta(c) mRNA expression and of immunoreactive cells within the lungs of Brown Norway (BN) rats when injected intratracheally (p < 0.01). Inhibition of beta(c) significantly reduced (p < 0.01) experimentally induced eosinophilia in vivo in ovalbumin (OVA)-sensitized BN rats after antigen challenge. Furthermore, when compared with mismatch-treated rats, beta(c) AS-ODN caused inhibition of antigen-induced airway hyperresponsiveness to leukotriene D4. Taken together, our findings demonstrate that the common beta(c) of IL-3, IL-5, and GM-CSF receptors is involved in the eosinophil influx and airway hyperresponsiveness that follow OVA challenge and underscore the potential utility of a topical antisense approach targeting beta(c) for the treatment of asthma.

Topics: Animals; Antigens; Asthma; Bone Marrow Cells; Bronchial Hyperreactivity; Cell Count; Cells, Cultured; Dose-Response Relationship, Drug; Eosinophils; Immunization; Leukotriene D4; Lung; Male; Oligonucleotides, Antisense; Ovalbumin; Rats; Rats, Inbred BN; Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; Receptors, Interleukin; Receptors, Interleukin-3; Receptors, Interleukin-5; RNA, Messenger; Transcription, Genetic

Airway hyperresponsiveness (AHR) is one of the characteristic features of human asthma. The presence of AHR and the precise mechanisms immediately after establishment of sensitization in guinea pigs are unclear, although there are many reports showing allergen exposure that causes an increase in bronchial responsiveness associated with eosinophil influx into the airway in sensitized guinea pigs.. We investigated the inhibitory effects on AHR to histamine of ONO-1078, a leukotriene antagonist; indomethacin, a cyclooxygenase inhibitor; S-145, a thromboxane A(2) (TXA(2)) antagonist, and Y-24180, a platelet-activating factor (PAF) antagonist, to assess the involvement of chemical mediators in AHR employing ovalbumin (OA) sensitized guinea pig models.. Male Hartley guinea pigs were used. Each group comprised 4-7 animals. The animals were sensitized to OA, injecting intraperitoneally 30 mg of cyclophosphamide and 2,000 microg of OA together with 100 mg of aluminum hydroxide as the adjuvant. The guinea pigs were artificially ventilated via a cannula using a small-animal respirator after intraperitoneal anesthesia with pentobarbital sodium for tracheotomy. The pressure at the airway opening (PAO) was measured using a differential pressure transducer, and a differential pressure of peak PAO (peak DeltaPAO) at inspiratory phase as an overall index of bronchial response to bronchoactive agents was used. While being artificially ventilated, the animals were exposed to physiological saline solution containing various concentrations of histamine (4.9, 9.8, 20, 39, 78, and 156 microg/ml) by inhalation for 30 s at 3-min intervals. Determinations were made at 1 min after each inhalation. The chemical mediators were each (30 mg/kg of ONO-1078, 3 mg/kg of S-1452, and 1 mg/kg of Y-24180) administered orally to sensitized guinea pigs, and the airway response to histamine was assessed. Each group comprised 4-7 animals.. The airway response to histamine was significantly greater in the sensitized group than in the nonsensitized group at histamine concentrations of 36 (p < 0.05), 78, and 156 mg/ml (p < 0.01). Leukotrienes C(4) and D(4): 30 mg/kg of ONO-178 did not show any inhibitory effect on airway response to inhaled histamine. Cyclooxygenase: 5 mg/kg of indomethacin did not show any inhibitory effect on the airway response to inhaled histamine. TXA(2): the AHR to inhaled histamine at doses of 9.8, 39, 78, and 156 microg/ml was significantly inhibited by prior administration of 3 mg/kg of S-1452. PAF: the AHR to inhaled histamine at doses of 9.8, 39, and 78 microg/ml was significantly inhibited by prior administration of 1 mg/kg of Y-24180.. S-1452 (3 mg/kg) and Y-24180 (1 mg/kg) significantly inhibited AHR to histamine, while ONO-108 (30 mg/kg) and indomethacin (5 mg/kg) did not. The results suggest that TXA(2) and PAF are involved in AHR in OA-sensitized guinea pigs.

Topics: Airway Resistance; Animals; Asthma; Bronchial Hyperreactivity; Disease Models, Animal; Dose-Response Relationship, Drug; Guinea Pigs; Histamine; Indomethacin; Leukotriene C4; Leukotriene D4; Male; Ovalbumin; Platelet Activating Factor; Probability; Reference Values; Sensitivity and Specificity; Thromboxane A2

Inhalational challenges with inflammatory mediators may provoke lung function disturbances similar to those shown in spontaneous acute asthma. Cysteinyl leukotrienes (CysLTs) have recently been established as mediators of bronchoconstriction in asthma but their effects on pulmonary gas exchange in asthma have not been assessed. We therefore investigated the effects of leukotriene D(4) (LTD(4)) challenge resulting in a significant decrease in FEV(1) (mean +/- SE, by 32 +/- 3%) in 13 nonsmoking, mild asthmatics. Respiratory system resistance (Rrs), and respiratory and inert gases were measured before and immediately after, and at 15 and 45 min after challenge. After bronchoprovocation, Rrs increased (by 106 +/- 12%), Pa(O(2)) decreased (by 25 +/- 4 mm Hg), and ventilation-perfusion distributions moderately to severely deteriorated, as shown by increases in the dispersions of pulmonary blood flow (Log SDQ, by 59 +/- 12%) and alveolar ventilation (Log SDV, by 65 +/- 20%) (p < 0.05 each). Sputum eosinophils (p < 0.05) and urinary LTE(4) (p < 0.005) increased after challenge. Despite the lack of mathematical correlations between spirometric and Rrs changes and gas exchange indices, the pattern of improvement of the functional variables after challenge ran in parallel. These findings support the evidence that CysLTs, in addition to being potent bronchoconstrictors, also provoke profound disturbances of pulmonary gas exchange in asthma.

Topics: Administration, Inhalation; Adult; Asthma; Female; Humans; Leukotriene D4; Male; Pulmonary Gas Exchange; Sputum

The cysteinyl (Cys) leukotrienes (LT)C(4), LTD(4), and LTE(4), are lipid mediators that have been implicated in the pathogenesis of asthma. The human LTD(4) receptor (CysLT(1)R) was recently cloned and characterized. The present work was undertaken to study the potential modulation of CysLT(1)R expression by the Th2 cytokines IL-13 and IL-4. In this study, we report that IL-13 up-regulates CysLT(1)R mRNA levels, with consequently enhanced CysLT(1)R protein expression and function in human monocytes and monocyte-derived macrophages. CysLT(1)R mRNA expression was augmented 2- to 5-fold following treatment with IL-13 and was due to enhanced transcriptional activity. The effect was observed after 4 h, was maximal by 8 h, and maintained at 24 h. IL-4, but not IFN-gamma, induced a similar pattern of CysLT(1)R up-regulation. Monocytes pretreated with IL-13 or IL-4 for 24 h showed enhanced CysLT(1)R protein expression, as assessed by flow cytometry using a polyclonal anti-CysLT(1)R Ab. They also showed enhanced responsiveness to LTD(4), but not to LTB(4), in terms of Ca(2+) mobilization, as well as augmented chemotactic activity. Our findings suggest a possible mechanism by which IL-13 and IL-4 can modulate CysLT(1)R expression on monocytes and macrophages, and consequently their responsiveness to LTD(4), and thus contribute to the pathogenesis of asthma and allergic diseases.

Topics: Asthma; Base Sequence; Chemotaxis, Leukocyte; DNA Primers; Humans; In Vitro Techniques; Interleukin-13; Interleukin-4; Leukotriene D4; Macrophages; Membrane Proteins; Monocytes; Receptors, Leukotriene; RNA, Messenger; Up-Regulation

To evaluate clinical significance of measurement of urinary leukotriene E4 (LTE4) in asthmatic patients without attack, we measured urinary LTE4 in 68 asthmatic patients without attack and investigated its correlation with severity of asthma, % FEV1, bronchial hyperresponsiveness and peripheral eosinophil counts. Values of urinary LTE4 were significantly higher in the asthmatic patients (113.6 +/- 9.7 pg/mg.cr) than in healthy control subjects (67.8 +/- 4.7, n = 31), and the level of urinary LTE4 was in proportion to the severity of disease. Urinary LTE4 showed significant negative correlation with % FEV1 in atopic patients (Rs = -0.43, p = 0.025, n = 28), which was not recognized in non-atopic patients. Urinary LTE4 showed no significant correlation with bronchial hyperresponsiveness and peripheral eosinophil counts. Our findings suggested that basal LTE4 in urine reflected chronic airway inflammation of asthma.

Topics: Adult; Asthma; Bronchial Hyperreactivity; Female; Humans; Leukotriene D4; Male; Middle Aged; Severity of Illness Index

We have used the relatively noninvasive technique of induced sputum to measure allergen-induced changes in the concentration of eicosanoid mediators in bronchial secretions from atopic asthmatics. Sputum induction was performed before and 24 h after inhalational allergen challenge in 14 atopic asthmatics who developed a late asthmatic reaction (LAR). Differential cell counts were made on sputum cytospins and eicosanoid (cysteinyl leukotrienes [cys LTs], prostaglandin D(2) [PGD(2)], and PGE(2)) concentrations were measured in the sputum supernatants. The percentage of eosinophils at baseline correlated with the concentration of cys LTs (r = 0.84, p < 0.001) but not prostanoid mediators. Allergen challenge produced a significant increase in the concentration of sputum cys LTs from 3. 45 ng/ml sputum to 11.95 ng/ml (p = 0.002), which correlated with the increase in sputum eosinophils (r = 0.55, p < 0.05). There were no significant changes in PGD(2) or PGE(2) concentrations in sputum supernatants in response to challenge. Thus, the noninvasive technique of induced sputum has been used to demonstrate increased cys LTs, but not prostanoids associated with LAR after allergen challenge. The correlation between eosinophil numbers and cys LT concentrations at baseline values and 24 h after allergen challenge is consistent with these cells being a principal source of cys LTs within the airways at these time points.

Topics: Adult; Allergens; Asthma; Bronchial Provocation Tests; Cell Count; Dinoprostone; Female; Humans; Hypersensitivity, Immediate; Leukotriene C4; Leukotriene D4; Leukotriene E4; Leukotrienes; Male; Middle Aged; Prostaglandin D2; Sputum

Cysteinyl leukotrienes are potent inflammatory molecules playing a major role in asthma. The involvement of these mediators in hypersensitivity in mice is not well known. This study aimed at elucidating their implication by using MK-571, a cysLT(1)receptor antagonist. Mice were sensitized with a suspension of ovalbumin (8 microg) adsorbed to alum (2 mg) and were challenged with an aerosolized ovalbumin solution (0.5%). Inflammatory cell infiltration in the bronchoalveolar lavage (mostly eosinophils) following antigen challenge was inhibited by dexamethasone (0.1, 1 and 5 mg kg(-1)s.c.) and MK-571 (1, 10, 100 mg kg(-1)i.v.) in a dose-dependent manner. Maximal inhibition was 95% with 5 mg kg(-1)dexamethasone and 90% with 100 mg kg(-1)MK-571. When injected together they showed an additive inhibitory effect on eosinophil infiltration. Bronchial hyperreactivity, measured by the increased pulmonary insufflation pressure to carbachol injections, was also inhibited dose-dependently by MK-571. The EC(50)values for carbachol were of 22.39+/-1.12 microg kg(-1)in sensitized and challenged animals that did not receive MK-571 and increased to 43.65+/-1.10, 50.12+/-1.15 and 83.18+/-1.16 microg kg(-1)in animals treated with 1, 10 and 100 mg kg(-1)MK-571 respectively. Lung microvascular leakage (as measured by Evans blue extravasation) induced by antigen bronchoprovocation was reduced by 22% after treatment with 10 mg kg(-1)MK-571. All these inhibitory effects of MK-571 suggest a role for leukotriene D(4)in this animal model of allergic asthma.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Capillary Permeability; Dexamethasone; Disease Models, Animal; Drug Therapy, Combination; Leukotriene Antagonists; Leukotriene D4; Male; Membrane Proteins; Mice; Mice, Inbred BALB C; Ovalbumin; Propionates; Pulmonary Eosinophilia; Quinolines; Receptors, Leukotriene

The effects of 7-[3-[4-(2-quinolinylmethyl)- 1-piperazinyl]propoxy]-2,3-dihydro-4H-1,4- benzothiazin-3-one (VUF-K-8788) on experimental asthmatic reactions in guinea pigs were investigated. VUF-K-8788 inhibited histamine-induced bronchoconstriction at the doses of 0.3 and 1 mg/kg per os (p.o.). VUF-K-8788 inhibited anaphylactic bronchoconstriction at doses between 0.01 and 1 mg/kg in passively sensitized guinea pigs. Terfenadine used as a reference drug also inhibited an antigen-induced bronchoconstriction. VUF-K-8788 at the doses of 0.3 and 1 mg/kg inhibited immediate- and late-phase asthmathic reactions in actively sensitized guinea pigs. Terfenadine inhibited only the immediate phase reaction. Moreover, VUF-K-8788 inhibited the infiltration of eosinophils and macrophages into bronchoalveolar lavage fluid in guinea pigs. These results indicate that VUF-K-8788 may be useful for the treatment of bronchial asthma.

Topics: Airway Resistance; Anaphylaxis; Animals; Anti-Allergic Agents; Anti-Asthmatic Agents; Antigens; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Electric Stimulation; Guinea Pigs; Histamine; Hypersensitivity, Delayed; Hypersensitivity, Immediate; Immunization, Passive; In Vitro Techniques; Leukotriene D4; Male; Piperazines; Thiazines

We compared the effects of natriuretic peptides on antigen-induced bronchoconstriction and airway microvascular leakage in sensitized guinea pigs. Anesthetized male guinea pigs, ventilated via a tracheal cannula, were placed in a plethysmograph to measure pulmonary mechanics for 10 min after challenge with 1 mg/kg of ovalbumin, and then Evans blue dye was extravasated into airway tissue in order to indicate and evaluate microvascular leakage. Three separate intravenous pretreatments using atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) significantly inhibited the ovalbumin-induced bronchoconstriction and microvascular leakage in a dose-dependent manner. These inhibitory effects were mimicked by 8-bromoguanosine 3',5'-cyclic monophosphate. We showed that the rank order of inhibitory potencies, which were mediated by cyclic guanosine 3',5'-monophosphate, was BNP > or = ANP > or = CNP. These results gave us some clues for the clinical application of the natriuretic peptides.

Topics: Animals; Antigens; Asthma; Atrial Natriuretic Factor; Blood Pressure; Bronchi; Bronchoconstriction; Capillary Permeability; Cyclic GMP; Disease Models, Animal; Guinea Pigs; Leukotriene D4; Male; Natriuretic Peptide, Brain; Natriuretic Peptide, C-Type; Nerve Tissue Proteins; Ovalbumin; Proteins; Trachea

We have recently demonstrated that tissue resistance increases during the early response to antigen challenge in sensitized Brown-Norway rats. The purpose of the present study was to investigate in vitro the dynamic tissue response to antigen challenge and the involvement of the mediators, i.e., serotonin (5HT) and leukotriene D4 (LTD4). In addition, we questioned whether strips from sensitized rats responded differently to nonspecific challenge compared with those of unsensitized controls. We sensitized Brown-Norway rats with ovalbumin and performed experiments using strips of subpleural parenchyma. Tissue strips were challenged with ovalbumin in the bath; in some experiments the tissues were exposed to methysergide (10(-6) M), a 5HT antagonist, or MK-571 (10(-6) M), a LTD4 receptor antagonist, or both, prior to challenge. At the end of the experiment all tissues were exposed to carbacholine (10(-3) M). Oscillation mechanics of tissue strips were studied and values of resistance (R), elastance (E), and hysteresivity (eta) were obtained. During ovalbumin challenge in sensitized tissues, R, E, and eta increased significantly (% change in R, 12.1 +/- 2.1%; % change in E, 3.8 +/- 1.3%; % change in eta, 9.3 +/- 2.8%). Both methysergide and MK-571 reduced the increase in R (3.0 +/- 0.6 and 3.2 +/- 0.8%, respectively, p < 0.05 vs. ovalbumin). There was no difference between sensitized and unsensitized strips in the response to carbacholine challenge. These data suggest that the oscillatory behaviour of tissue strips from sensitized rats is altered after ovalbumin challenge. The mechanism of that response is mediated by both 5HT and LTD4.

Topics: Animals; Antigens; Asthma; Carbachol; Leukotriene D4; Lung; Muscarinic Agonists; Rats; Serotonin; Serotonin Antagonists

The cysteinyl leukotrienes (CysLTs) mimic many of the features of asthma and are implicated in its pathophysiology. Little, however, is known about the effects of the CysLTs on airways remodeling. In this study the effects of leukotriene D4 (LTD4) on human airway smooth muscle (HASM) cell proliferation and expression of extracellular matrix proteins were investigated. LTD4 (0.1-10 microM) alone had no effect on DNA synthesis in HASM. LTD4, however, markedly augmented proliferation induced by the mitogen, epidermal growth factor (EGF, 1 ng/ml). The potentiating effect of LTD4 (1 microM) on EGF-induced DNA synthesis was abolished by pranlukast (1 microM) or pobilukast (30 microM), but unaffected by zafirlukast (1 microM). In contrast, pranlukast (pKB = 6.9), pobilukast (pKB = 7.0), and zafirlukast (pKB = 6.5) had equivalent potencies for inhibition of LTD4-induced contraction in human bronchus. LTD4 (0.1 or 10 microM) did not increase the total messenger RNA expression of the extracellular matrix proteins (pro-alpha[I] type I or alpha1[IV] type IV collagen), elastin, biglycan, decorin, and fibronectin, and did not influence tumor growth factor-beta (10 ng/ml)-induced effects on the expression of these proteins in HASM cells. These data indicate that LTD4 augments growth factor-induced HASM proliferation but does not alter the expression of various extracellular matrix components. The observed differences in sensitivity to the antagonists suggests that the former phenomenon may be mediated by a CysLT receptor distinct from that which mediates LTD4-induced HASM contraction. Collectively, these results provide preliminary evidence that CysLTs may play a role in airways remodeling in asthma.

Topics: Asthma; Carbachol; Cells, Cultured; Chromones; Dicarboxylic Acids; DNA Replication; Epidermal Growth Factor; Extracellular Matrix Proteins; Gene Expression Regulation; Humans; Indoles; Leukotriene Antagonists; Leukotriene D4; Membrane Proteins; Muscle Contraction; Muscle, Smooth, Vascular; Phenylcarbamates; Receptors, Leukotriene; RNA, Messenger; Sulfonamides; Tosyl Compounds; Trachea; Transforming Growth Factor beta

1. It has been shown that activation of protein tyrosine kinases is the earliest detectable signalling response to FcepsilonRI cross-linking on mast cell. Following tyrosine kinase activation, a family of mitogen-activated protein kinases (MAPKs) was found to be activated as well. The present study examined the role of MAPK signalling cascade in in vitro model of allergic asthma using a specific MAPK kinase inhibitor PD 098059. 2. Guinea-pigs were passively sensitized with IgG antibody raised against ovalbumin (OA). Effects of PD 098059 on OA-induced anaphylactic contraction of isolated bronchi and release of histamine and peptidoleukotrienes from chopped lung preparations were studied. 3. PD 098059 (10-50 microM) produced only minor reduction of maximal OA-induced bronchial contraction. In contrast, the rate of relaxation of OA-induced bronchial contraction was markedly faster in the presence of PD 098059 than the vehicle control in a concentration-dependent manner. 4. These observations corroborate well with the inability of PD 098059 (5-50 microM) to substantially block the OA-induced release of histamine and with marked inhibition of OA-induced release of peptidoleukotrienes from lung fragments in the presence of PD 098059. Exogenous arachidonic acid-induced release of peptidoleukotrienes from lung fragments was not blocked by PD 098059. 5. In immunoblotting study, we found that p42MAPK was constitutively expressed in guinea-pig bronchi. However, treatment with OA, histamine or LTD4 did not cause activation of p42MAPK. These findings together with the lack of inhibitory effects of PD 098059 on bronchial contraction induced by histamine or LTD4 suggest that histamine- and LTD4-induced bronchial contractions are not mediated by p42MAPK activation. 6. Taken together, our findings show that inhibition of MAPK signalling cascade by PD 098059 significantly reduced the OA-triggered release of peptidoleukotrienes leading to rapid relaxation of anaphylactic bronchial contraction. On the other hand, p42MAPK did not play a role in histamine- or LTD4-induced bronchial smooth muscle contraction suggesting that PD 098059 exerts its inhibitory effects on OA-induced bronchial contraction primarily through inhibition of peptidoleukotrienes release from mast cells.

Topics: Analysis of Variance; Animals; Asthma; Bronchi; Bronchoconstriction; Dose-Response Relationship, Drug; Enzyme Activation; Enzyme Inhibitors; Flavonoids; Guinea Pigs; Histamine Release; Hypersensitivity; Immunoglobulin G; In Vitro Techniques; Leukotriene D4; Lung; Male; Mast Cells; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase Kinases; Ovalbumin; Protein Kinase Inhibitors; Protein Kinases

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.

Topics: Aminoquinolines; Animals; Arginine; Asthma; Capillary Permeability; Coloring Agents; Dipeptides; Enzyme Inhibitors; Evans Blue; Extravasation of Diagnostic and Therapeutic Materials; Guanylate Cyclase; Guinea Pigs; Histamine; Indoles; Inflammation Mediators; Injections, Intravenous; Leukotriene D4; Lung; Male; Microcirculation; Neurokinin-1 Receptor Antagonists; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; omega-N-Methylarginine; Organometallic Compounds; Substance P

The present study was conducted to examine the effects of two protein tyrosine kinase inhibitors, genistein and tyrphostin 47, on an in vitro model of allergic asthma. Guinea pigs were sensitized with purified IgG raised against ovalbumin (OA). Isolated sensitized bronchial rings contracted in response to OA in a concentration-dependent manner, maximum contraction being achieved at 1 microg/ml. Genistein and tyrphostin 47 concentration-dependently (10-100 microM) inhibited OA-induced anaphylactic contraction of the bronchi, as well as release of histamine and peptidoleukotrienes from chopped lung preparations. Genistein, but not tyrphostin 47, significantly suppressed bronchial contraction to leukotriene D4 at 50 microM and to histamine at 100 microM. Daidzein, an inactive congener of genistein, did not alter OA-induced anaphylactic contraction. However, it slightly reduced bronchial contraction to leukotriene D4 and the OA-stimulated release of peptidoleukotrienes. The inhibitory effects were significantly weaker than those of genistein. Taken together, our results show that tyrphostin 47 inhibited anaphylactic contraction mainly by preventing mast cell degranulation, whereas genistein exerted inhibitory effects partly by blocking mast cell degranulation and partly by attenuating leukotriene D4-induced bronchial contraction. These findings suggest that protein tyrosine kinase inhibitors have a therapeutic potential as mast cell stabilizers in the treatment of allergic diseases such as bronchial asthma.

Topics: Anaphylaxis; Animals; Antigens; Asthma; Bronchoconstriction; Enzyme Inhibitors; Genistein; Guinea Pigs; Histamine Release; In Vitro Techniques; Isoflavones; Leukotriene D4; Nitriles; Phenols; Protein-Tyrosine Kinases; Rabbits; Tyrphostins

Topics: Animals; Asthma; Cyclosporine; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Freund's Adjuvant; Guinea Pigs; Histamine Release; Immunosuppressive Agents; Leukotriene C4; Leukotriene D4; Leukotriene E4; Male; Muscle Contraction; Muscle, Smooth; Ovalbumin; Radioimmunoassay; Trachea

We studied the effect of a new antiallergic compound, TYB-2285 (3,5-bis(acetoxyacetylamino)-4-chlorobenzonitrile), on antigen-induced early and late bronchoconstriction and airway responsiveness in conscious allergic sheep. The same general protocol was used for all studies, except that the dosage and time of TYB-2285 treatment was varied. The basic protocol consisted of determining airway responsiveness to inhaled carbachol, then measuring the airway responses to Ascaris suum antigen challenge followed 1 day later by a post challenge assessment of airway responsiveness. Specific lung resistance (SRL) was used to measure the airway responses to antigen and carbachol and the concentration of carbachol that caused a 400% increase in SRL (PC400) was used as a measure of airway responsiveness. All protocols were of crossover design, such that each sheep served as its own control and each protocol employed six to eight animals. In all instances, TYB-2285 or vehicle control (methylcellulose) was given orally. When TYB-2285 (100 mg/kg) was given at 16 and 2 h before the challenge, the early response, the late response and the post antigen-induced airway hyperresponsiveness (AHR) as indicated by a decrease in the PC400 was inhibited significantly. TYB-2285 (100 mg/kg), when given 1 h after challenge, inhibited the late response and AHR significantly. TYB-2285 (100 mg/kg), when given 8 h after the challenge, also inhibited the antigen-induced AHR. When animals were given TYB-2285 (100 mg/kg) at 32, 56 and 80 h after the challenge, the antigen-induced AHR that persisted (for 1 week) in the control trial was reversed to the normal level. TYB-2285 (30 mg/kg), when given at 1, 32, 56 and 80 h after the challenge, inhibited late response slightly and reversed the persistent AHR to the normal level. At lower doses (3 and 10 mg/kg) there was no protection of the early response, the late response or AHR. Pretreatment with TYB-2285 (100 mg/kg) also prevented the antigen-induced influx of eosinophils in bronchoalveolar lavage obtained 24 h after segmental antigen challenge. TYB-2285 did not inhibit histamine or LTD4-induced bronchoconstriction nor did the active metabolites of TYB-2285, TC-286 and TC-326 inhibit acetylcholine-induced contraction of sheep tracheal smooth muscle. These results suggest that TYB-2285 has both antiallergic and antiinflammatory properties in the sheep model of allergic bronchoconstriction. The compound demonstrates both prophylactic and therapeut

Topics: Animals; Asthma; Bronchi; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Bronchoconstrictor Agents; Cross-Over Studies; Eosinophils; Histamine; Leukotriene D4; Nitriles; Sheep; Trachea

We demonstrated the effect of a novel selective type IV phosphodiesterase (PDE) IV inhibitor, T-440 (1-[1-(2-methoxyethyl)pyrid-2-one-4-yl]-2,3-bis (hydroxymethyl)-6,7-diethoxynaphthalene), on antigen- and chemical mediator-induced bronchoconstrictions in anesthetized guinea pigs in vivo. Intravenously (i.v.) administered T-440 inhibited antigen-induced bronchoconstriction dose-dependently in passively sensitized guinea pigs (ED50 = 2.3 mg/kg). Histamine-, leukotriene (LT) D4-, U-46619-, acetylcholine (ACh)-, neurokinin A- and endothelin-1-induced bronchoconstrictions were also inhibited by i.v. injected T-440. Most potent suppression was produced against the bronchoconstriction induced by LTD4 (ED50 = 0.89 microgram/kg), whereas the effect against ACh was very weak (ED50 = 1.8 mg/kg). Additionally, T-440 inhibited histamine-induced bronchoconstriction by intraduodenal and intratracheal administration (ED50 and EC50 = 1.6 mg/kg and 0.50 mg/ml, respectively). Bronchoconstrictions induced by antigen and chemical mediators were also suppressed by theophylline. However, all of these anti-spasmolytic effects of theophylline were less potent than those of T-440 (1.8-110 times). Our results indicate the importance of PDE IV in bronchodilation, and PDE IV inhibitors may have potential as anti-asthma drugs.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Analysis of Variance; Animals; Asthma; Bronchoconstriction; Dose-Response Relationship, Drug; Guinea Pigs; Histamine Antagonists; Injections, Intravenous; Leukotriene D4; Male; Naphthalenes; Phosphodiesterase Inhibitors; Prostaglandin Endoperoxides, Synthetic; Pyridones; Rabbits; Thromboxane A2; Vasoconstrictor Agents

To study the asthmatogenic effect of certain airborne elements of the home environment, we studied a group of guinea pigs exposed to aerosolized cockroach allergen (CRa) and side-stream cigarette (S-SC) smoke. Four groups of guinea pigs were exposed to aerosols, either saline or CRa, for 4 weeks, after a sham or S-SC smoke pretreatment. Anaphylactic antibodies were measured by passive cutaneous anaphylaxis (PCA) assay and by skin test. Animals were challenged with aerosol CRa on day 35, and lung function and leukotrienes (LTB4 and LTC4/D4) were measured. Skin tests were positive on days 21 and 29. The antibodies were heat-stable, IgG1a-like antibodies (PCA titers 1:2-18). The CRa challenge caused an immediate reduction in both the maximal expiratory flow rate at 50% of the lung capacity and respiratory compliance. The decreased lung function continued for up to 6 h (p < 0.0001). LTB4 and LTC4/D4 were elevated (p < 0.0001) in the sensitized animals at the corresponding times of reduced lung function. S-SC smoke did not affect the CRa sensitization; instead, a protective effect on the CRa-induced bronchospasms was noted. Thus, the study indicates that a simple airborne CRa exposure without an adjuvant sensitizes guinea pigs, and that the animals respond to antigen challenge with CRa-specific airway obstructions.

Topics: Aerosols; Air Pollution, Indoor; Allergens; Animals; Asthma; Cockroaches; Disease Models, Animal; Environmental Exposure; Guinea Pigs; Immunoglobulin G; Leukotriene B4; Leukotriene C4; Leukotriene D4; Lung; Male; Passive Cutaneous Anaphylaxis; Respiratory Function Tests; Skin Tests; Tobacco Smoke Pollution

Human airways in vitro contract when stimulated by anti-IgE, whereas human pulmonary vessels relax. Leukotriene D4 (LTD4) induced a contractile response in the airways, while in pulmonary vessels both contractions and relaxations were observed. The LTD4 contractions in airways were blocked by cysLT1 receptor antagonists (MK 571, ICI 198615, and BAY x7195). In contrast none of the compounds affected the LTD4 contractions of pulmonary veins. These results suggest that the leukotrienes which are released during antigen challenge of airways and pulmonary vessels may be acting at distinct receptors in the human lung.

Topics: Antigens; Asthma; Bronchi; Bronchodilator Agents; Cell Separation; Humans; Hydroxy Acids; Indazoles; Leukotriene D4; Muscle, Smooth; Norepinephrine; Propionates; Pulmonary Veins; Quinolines

Leukotrienes (LK) play an important role in the inflammatory response found in the asthmatic airway and it is therefore of interest to explore the clinical value of agents which can either block the effect or inhibit the synthesis of leukotrienes. If tachyphylaxis does not develop, repeated LTD4 challenges can be used for dose ranging studies. Tachyphylaxis has been observed when LTD4 challenge intervals are kept below 1 h, but the effect of prolonging the interval is uncertain. The aim of this study was therefore to investigate the interval between LTD4 challenges necessary to avoid development of tachyphylaxis. Ten stable adult asthmatics with moderate asthma were challenged seven times: a screening day to secure responsiveness to LTD4, two challenges on three separate days with an interval of 2, 4 and 6 h, respectively. No significant differences between mean PC20-LTD4 values (P > 0.5) was found. It was concluded that tachyphylaxis to repeated LTD4 challenges of asthmatics does not develop when challenge intervals are prolonged above 2 h.

Topics: Administration, Inhalation; Adult; Asthma; Bronchial Provocation Tests; Bronchoconstriction; Female; Forced Expiratory Volume; Humans; Leukotriene D4; Male; Middle Aged; Reproducibility of Results; Tachyphylaxis; Time Factors

Airway reactivity to bronchoconstrictor mediators changes with age. We studied the effects of maturational change on airway responses induced by a thromboxane A2 mimetic, U-46619 (2, 6 and 20 nmol/kg; i.v.), leukotriene D4 (0.6 and 2 nmol/kg; i.v.) or vehicle (0.9% NaCl; i.v.) in immature (196 +/- 3 g: 2 weeks) and adult guinea pigs (512 +/- 5 g: 11 weeks). In the same animals, we measured both lung resistance (RL) to monitor airflow obstruction and extravasation of Evans Blue dye (20 mg/kg) to quantify airway plasma exudation. For a comparison, changes in RL in response to acetylcholine (5, 15 and 50 nmol/kg; i.v.) were also examined in both age groups. The order of potency to induce an increase in RL did not change with age (leukotriene D4 > U-46619 > acetylcholine). In immature animals, the peak RL after U-46619 (2, 6 and 20 nmol/kg; P < 0.05, P < 0.005 and P < 0.01, respectively) and leukotriene D4 (2 nmol/kg; P < 0.01) was significantly higher than in adult animals. U-46619 and leukotriene D4 produced significant extravasation of Evans Blue dye in both immature and adult animals. The order of potency to induce extravasated dye also did not change with age (leukotriene D4 > U-46619). The amount of extravasation of Evans Blue dye after U-46619 (6 and 20 nmol/kg) and leukotriene D4 (0.6 and 2 nmol/kg) was significantly smaller in immature animals than adults at all airway levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Airway Resistance; Animals; Asthma; Blood Pressure; Capillary Permeability; Eicosanoids; Evans Blue; Guinea Pigs; Leukotriene D4; Male; Prostaglandin Endoperoxides, Synthetic; Respiratory Function Tests; Respiratory System; Thromboxane A2; Vasoconstrictor Agents

The ovalbumin (OA)-sensitized Brown Norway rat (BN) demonstrates early-response (ER) and late-response (LR) allergic bronchoconstriction. To determine whether these responses could be replicated in vitro, we studied lung explants from 8-wk-old male BN rats (wt: 239 +/- 28 g), of which 19 were sensitized to OA (test) and 16 served as controls. Two weeks after sensitization, the animals' lungs were removed, filled with a 1% (wt/vol) agarose-containing solution at 37 degrees C, and cooled to 4 degrees C. Transverse slices (0.5 to 1.0 mm thick) were cut and cultured overnight. Airways were visualized with an inverted microscope and baseline images were obtained with a video camera. To study the ER, 40 airways from 15 test rats and 29 airways from 10 control rats were challenged with 2 micrograms OA and imaged each minute for 10 min. To study the LR, 40 airways from 12 test rats and 44 airways from 12 control rats were challenged with 2 micrograms OA and imaged each hour for 8 h. The maximal response (MR) for each airway was defined as the percent of airway closure. The ER and LR were both defined as an MR > or = mean + 2 SD of the controls. An ER occurred in 38 of 40 test and 2 of 29 control airways (mean MR: 42 +/- 24% versus 4 +/- 3%, p < 0.001), and was completely blocked by methysergide pretreatment in 13 airways.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Airway Resistance; Animals; Asthma; Bronchial Provocation Tests; Bronchodilator Agents; Constriction, Pathologic; Disease Models, Animal; Drug Hypersensitivity; Hypersensitivity, Delayed; Hypersensitivity, Immediate; Immunoglobulin E; In Vitro Techniques; Leukotriene D4; Male; Methysergide; Ovalbumin; Premedication; Propionates; Quinolines; Rats; Serotonin; Time Factors

To assess the contribution of the leukotrienes, LTC4, D4, E4 and B4 during bronchial asthma attacks, simultaneous determination was made of their levels in venous blood. 25 patients with bronchial asthma (15 atopic types, 10 non-atopic types) participated in this study and 4 normal controls were used. Samples were obtained using heparinized syringe from the patients before treatment. A radioimmunoassay was conducted to measure LTs after purification with a Sep-pak column and separation by HPLC. In normal subjects, the levels were less than the minimal detectable amounts. LTC4, D4, E4 and B4 during asthmatic attacks were 100 +/- 179, 88 +/- 116, 479 +/- 291, and 55 +/- 73 (Mean +/- SD) pg/ml respectively (n = 27). Peptide LTs in remission were below minimal detectable levels. LTD4 in patients with moderate attacks was significantly (p < 0.05) higher than in those with mild attacks. Peptide LTs in moderate attack exceeded those in mild attacks, although not to a statistically significant degree. No significant differences in LT during attacks could be detected in atopic or non-atopic type patients. LTs would thus appear importantly involved in asthmatic attacks in atopic and non-atopic type patients, although other chemical mediators may give rise to airway inflammation.

Topics: Adolescent; Adult; Aged; Asthma; Chromatography, High Pressure Liquid; Female; Humans; Leukotriene B4; Leukotriene C4; Leukotriene D4; Leukotriene E4; Leukotrienes; Male; Middle Aged; Radioimmunoassay

Western red cedar asthma is the most common form of occupational asthma in the Pacific Northwest. Plicatic acid (PA) is the chemical component of Western red cedar that causes asthma. The role of immunologic processes involved in the PA-induced asthmatic reaction has not been established. To characterize the mechanisms of PA-induced asthmatic reaction, guinea pigs were sensitized to PA through biweekly injection of PA-ovalbumin conjugate with aluminum hydroxide as an adjuvant for a period of 6 months. Specific IgG1 antibodies to PA were detected in the blood 3 months after sensitization of animals. The level of specific IgG1 antibodies to ovalbumin after 6 months was about two times the level of specific IgG1 to PA. At 6 months, tracheal tissue from PA-ovalbumin-sensitized guinea pigs contracted after exposure to either PA or ovalbumin in vitro. The degree of contraction induced by PA was two to three times less than the contraction induced by ovalbumin. PA caused histamine, prostaglandin D2, and leukotriene D4 release from both lung mast cells and blood basophils. The amount of histamine and eicosanoids released by PA was also two to three times less than the amount of mediators released by ovalbumin. When the trachea of normal guinea pigs was passively sensitized with serum from PA-ovalbumin-sensitized guinea pigs, it contracted in response to PA or ovalbumin in an organ bath. When the serum of PA-ovalbumin-sensitized guinea pigs was depleted of immunoglobulins and then used for passive sensitization of normal trachea, no contraction was observed when challenged with PA, suggesting that IgG1 antibodies mediate the tracheal reaction to PA.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Allergens; Animals; Asthma; Disease Models, Animal; Guinea Pigs; Immunization; Immunoglobulin G; In Vitro Techniques; Leukotriene D4; Lignans; Lung; Male; Muscle Contraction; Muscle, Smooth; Naphthols; Prostaglandin D2; Time Factors; Trachea; Trees

Topics: Aspirin; Asthma; Humans; Leukotriene C4; Leukotriene D4; Leukotriene E4; Leukotrienes