leukotriene-b4 and Asthma

Leukotriene B

Topics: Animals; Asthma; Humans; Leukotriene B4; Mice; Receptors, Leukotriene B4; Skin; Wound Healing

Leukotriene B

Topics: Animals; Asthma; Leukocytes; Leukotriene B4; Mice; Psoriasis; Receptors, Leukotriene B4

For several decades, the leukotriene pathways have been implicated as playing a central role in the pathophysiology of asthma. The presence and elevation of numerous metabolites in the blood, sputum, and bronchoalveolar lavage fluid from asthmatics or experimental animals adds support to this notion. However, targeting of the leukotriene pathways has had, in general, limited success. The single exception in asthma therapy has been targeting of the cysteinyl leukotriene receptor 1, which clinically has proven effective but only in certain clinical situations. Interference with 5-lipoxygenase has had limited success, in part due to adverse drug effects. The importance of the LTB4-BLT1 pathway in asthma pathogenesis has extensive experimental support and findings, albeit limited, from clinical samples. The LTB4-BLT1 pathway was shown to be important as a neutrophil chemoattractant. Despite observations made more than two decades ago, the LTB4-BLT1 pathway has only recently been shown to exhibit important activities on subsets of T lymphocytes, both as a chemoattractant and on lymphocyte activation, as well as on dendritic cells, the major antigen presenting cell in the lung. The role of BLT2 in asthma remains unclear. Targeting of components of the LTB4-BLT1 pathway offers innovative therapeutic opportunities especially in patients with asthma that remain uncontrolled despite intensive corticosteroid treatment.

Topics: Animals; Asthma; Chemotaxis; Dendritic Cells; Humans; Leukotriene B4; Lymphocyte Activation; Neutrophils; Receptors, Leukotriene B4; Signal Transduction; T-Lymphocytes

Chemoattractants are pivotal mediators of host defense, orchestrating the recruitment of immune cells into sites of infection and inflammation. Chemoattractants display vast chemical diversity and include bioactive lipids, proteolytic fragments of serum proteins, and chemokines (chemotactic cytokines). All chemoattractants induce chemotaxis by activating seven-transmembrane-spanning GPCRs expressed on immune cells, establishing the concept that all chemoattractants are related in function. However, although chemoattractants have overlapping functions in vitro, recent in vivo data have revealed that they function, in many cases, nonredundantly in vivo. The chemically diverse nature of chemoattractants contributes to the fine control of leukocyte trafficking in vivo, with sequential chemoattractant use guiding immune cell recruitment into inflammatory sites. Lipid mediators frequently function as initiators of leukocyte recruitment, attracting the first immune cells into tissues. These initial responding immune cells produce cytokines locally, which in turn, induce the local release of chemokines. Local chemokine production then markedly amplifies subsequent waves of leukocyte recruitment. These new discoveries establish a paradigm for leukocyte recruitment in inflammation--described as lipid-cytokine-chemokine cascades--as a driving force in the effector phase of immune responses.

Topics: Animals; Arthritis, Experimental; Asthma; Chemokines; Chemotactic Factors; Chemotaxis, Leukocyte; Cytokines; Gene Expression Regulation; Humans; Inflammation; Inflammation Mediators; Leukocytes; Leukotriene B4; Lipids; Mice; Neutrophils; Receptors, G-Protein-Coupled; Receptors, Leukotriene B4; Signal Transduction; Th2 Cells

Leukotriene (LT) B(4) is a potent inflammatory lipid mediator that has been involved in the pathophysiology of respiratory diseases including asthma. Exhaled breath condensate (EBC) is a non-invasive method to sample secretions from the airways. LC/MS/MS techniques for measuring LTB(4) concentrations in EBC have been developed and are suitable for an accurate quantitative assessment of its concentrations in EBC. LC/MS/MS for other eicosanoids including 8-isoprostane, a marker of oxidative stress, and cysteinyl-LTs have been developed. This article, mainly focused on LTB(4), presents the analytical aspects of the LC/MS/MS techniques for measuring LTB(4) and 8-isoprostane in EBC, provides examples of their application to the assessment of airway inflammation in patients with asthma and other respiratory diseases, and discusses their potential utility for non-invasive monitoring of drug therapy.

Topics: Asthma; Breath Tests; Child; Chromatography, Liquid; Drug Monitoring; Eicosanoids; Humans; Leukotriene B4; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

The contribution of CD8+ T cells to the development of airway hyperresponsiveness and airway inflammation has received increased attention recently. CD8+ T cells, which are capable of secreting TH2 cytokines, including IL-4, IL-5, and IL-13, have been described in asthmatic subjects and in animals sensitized and challenged with allergen. A subset of these IL-13-producing CD8+ T cells, effector memory CD8+ T cells in the mouse, express a high-affinity receptor for leukotriene B4 (BLT1), and expression of this receptor is essential for their accumulation in the lung and development of airway hyperresponsiveness and airway inflammation. A similar subset of CD8+/BLT1+/IL-13+ T cells has also been identified in the bronchoalveolar lavage fluid of asthmatic subjects, suggesting a pathogenic role for this unique subset of CD8+ T cells in asthma.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; CD8-Positive T-Lymphocytes; Cytokines; Disease Models, Animal; Disease Progression; Humans; Leukotriene B4; Mice

Exhaled breath condensate (EBC) is a novel, non-invasive method for obtaining samples from the lung. Use of exhaled condensate as a source of biomarkers is based on the hypothesis that aerosol particles of exhaled breath reflect the composition of airway lining fluid. The technique is simple to perform, effort-independent, rapid, may be repeated frequently, and can be easily perform even in young children, adults, or patients with severe disease. EBC contains large number of various mediators including isoprostanes, cysteinyl-leukotrienes, adenosine, hydrogen peroxide, peptides, cytokines. Concentrations of these biomarkers are influenced by inflammation, oxidative stress and modulated by therapeutic interventions. EBC can be used to assess airway inflammation and oxidative stress in the respiratory tract, in differential diagnosis of airway disease and in the treatment monitoring.

Topics: Adult; Ammonia; Asthma; Biomarkers; Breath Tests; Bronchitis; Carbon Monoxide; Child; Diagnosis, Differential; Exhalation; Humans; Hydrogen Peroxide; Inflammation Mediators; Isoprostanes; Leukotriene B4; Nitric Oxide; Oxidative Stress; Respiratory System

Topics: Animals; Asthma; Humans; Hypersensitivity; Immune System Diseases; Leukotriene B4; Leukotrienes; Membrane Proteins; Pulmonary Fibrosis; Receptors, Leukotriene; Receptors, Leukotriene B4; Signal Transduction

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

Recruitment of T cells to the airways is crucial in the pathogenesis of asthma, and it is thought to be mediated mainly by peptide chemokines. By contrast, lipid mediators such as leukotrienes and prostaglandins have classically been thought to contribute to asthma pathogenesis by other mechanisms. However, as we discuss here, the recent molecular identification of leukotriene and prostaglandin receptors, as well as the generation of mice that are genetically deficient in them, has revealed that two of these lipids - leukotriene B(4) and prostaglandin D(2) - also direct T-cell migration and seem to cooperate with chemokines in a non-redundant, sequential manner to recruit T cells to the airways in asthma.

Topics: Animals; Asthma; Cell Movement; Humans; Leukotriene B4; Lipid Metabolism; Prostaglandin D2; Receptors, Immunologic; Receptors, Leukotriene B4; Receptors, Prostaglandin; T-Lymphocytes

Topics: Animals; Asthma; Cysteine; Eosinophilia; Humans; Leukotriene B4; Leukotrienes; Neutrophils

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

Leukotrienes are potent pro-inflammatory mediators that appear to contribute to pathophysiologic features of asthma. For example, cysteinyl leukotrienes contract airway smooth muscle, increase microvascular permeability, stimulate mucus secretion, decrease mucociliary clearance, and appear capable of recruiting eosinophils into the airways. Segmental antigen bronchoprovocation in patients with asthma increases LTC4 concentrations in bronchoalveolar lavage fluid, which correlates with an influx of eosinophils into the airways. LTB4, in comparison, selectively affects neutrophil functions. Intratracheal instillation of LTB4 produced a selective recruitment of neutrophils into the lung. These effects suggest that leukotrienes contribute significantly to the inflammatory components of asthma.

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; Cysteine; Humans; Inflammation; Leukotriene B4; Leukotrienes; SRS-A

There have been significant advances in our understanding of the role of eicosanoids as mediators in inflammation since their discovery over 50 years ago. Our more recent understanding of asthma as an inflammatory disease has led to the appreciation of eicosanoids potentially being pivotal mediators in promoting some of the changes in asthma. Of particular importance are the cysteinyl LTs in producing bronchospasm and bronchial hyperresponsivenss, and PGE2 in modulating the bronchospastic and inflammatory response. Evidence from clinical studies suggests that other eicosanoids may also contribute, but their importance is secondary and their relative contributions vary between individuals. The development of new drugs based on our partial understanding of the role that eicosanoid mediators may play in asthma promises new approaches to the treatment of this common chronic inflammatory condition.

Topics: Asthma; Eicosanoids; Epoprostenol; Humans; Leukotriene Antagonists; Leukotriene B4; Leukotrienes; Lipoxygenase Inhibitors; Prostaglandins; Thromboxanes

Bronchoalveolar lavage (BAL) has been studied in asthmatic patients; it is a well-tolerated procedure and can be used in clinical practice to evaluate individual patients. However, the main question is: Does BAL contribute to a better understanding of the pathophysiology of bronchial asthma? The arguments in favour are as follows: (1) experiments in monkeys, indicating that the cells recovered by BAL contribute to the triggering of asthma; (2) demonstration of inflammatory cell (eosinophils, neutrophils, and lymphocytes) influx after allergen inhalation challenge, and (3) in vitro demonstration of cellular activation corresponding with clinical symptoms. BAL offers a new approach to the understanding of asthma. There is a lot of unresolved questions which should encourage us to exploit its potential to the full.

Topics: Asthma; Blood Proteins; Bronchoalveolar Lavage Fluid; Eosinophil Granule Proteins; Eosinophils; Humans; Leukotriene B4; Lymphocytes; Macrophages; Ribonucleases; SRS-A; Therapeutic Irrigation

Topics: Asthma; Chemotactic Factors; Histamine Release; Humans; Hypersensitivity, Immediate; Leukotriene B4; Peptides; Platelet Activating Factor; Prostaglandins; SRS-A

Topics: Acetophenones; Asthma; Chromones; Epoprostenol; Humans; Hydroxyquinolines; Keto Acids; Leukotriene B4; Phenylbutyrates; Quinolines; SRS-A; Sulfones; Tetrazoles

Topics: Animals; Asthma; Humans; Leukotriene B4; Lung; Muscle Tonus; Muscle, Smooth; Respiratory Physiological Phenomena; Respiratory Tract Diseases; SRS-A; Trachea

Evidence has been presented that lipoxygenase products of arachidonic acid metabolism released during the early stages of allergic reactions play an important role in the subsequent development of late bronchial responses. Moreover, because of this, the activity of the lipoxygenase pathway and sensitivity to the products generated may be important factors that distinguish between dual and acute responders. We recognize that these studies were performed in an experimental animal model of allergic airway disease. If the same mechanisms that are active in sheep are proven active in humans, then pharmacologic modification of the lipoxygenase pathway or its products (or both) may be important for the treatment of some forms of asthma.

Topics: Allergens; Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Arachidonic Acids; Asthma; Bronchial Spasm; Disease Models, Animal; Hypersensitivity, Delayed; Hypersensitivity, Immediate; Leukotriene B4; Models, Biological; Platelet Activating Factor; Prostaglandin-Endoperoxide Synthases; Sheep; SRS-A

Topics: Acetophenones; Allergens; Animals; Asthma; Bronchial Provocation Tests; Bronchial Spasm; Dogs; Humans; Leukotriene B4; Leukotriene E4; Sheep; SRS-A; Tetrazoles

Topics: Asthma; Basophils; Cell Communication; Endothelium, Vascular; Eosinophils; Humans; Inflammation; Leukotriene B4; Leukotriene E4; Mast Cells; SRS-A

Topics: Animals; Asthma; Bronchial Provocation Tests; Drug Interactions; Guinea Pigs; Histamine; Humans; Leukotriene B4; Lung; Muscle Contraction; Muscle, Smooth; Receptors, Leukotriene; Receptors, Prostaglandin; SRS-A

Topics: Anaphylaxis; Arachidonic Acids; Asthma; Bronchitis; Histamine; Humans; Leukotriene B4; Lipid Metabolism; Platelet Activating Factor; SRS-A

Topics: Anaphylatoxins; Arachidonic Acid; Arachidonic Acids; Asthma; Eicosanoic Acids; Fatty Acids; Humans; Leukocytes; Leukotriene B4; Lung; Macrophage Activation; Mucus; Platelet Activating Factor; Pneumonia; Prostaglandin-Endoperoxide Synthases; Respiratory Distress Syndrome; SRS-A

Topics: Aspirin; Asthma; Bronchi; Bronchial Provocation Tests; Eosinophils; Histamine Release; Humans; Immunoglobulin E; Indomethacin; Leukotriene B4; Mast Cells; Neutrophils; Pulmonary Alveoli; SRS-A

Leukotrienes (LT), which are derived from arachidonic acid and have similar chemical structures to the prostaglandins, have recently been shown to contain most of the biological activity previously attributed to "Slow Reacting Substance of Anaphylaxis" (SRS-A). LTC4, LTD4 and LTE4 have potent bronchoconstrictor actions. LTE4 causes very long-lasting bronchoconstriction. LTB4 has inflammatory properties and possesses powerful chemotactic activity on leukocytes, especially neutrophil polymorphonuclear cells. The involvement of leukotrienes in the pathogenesis of bronchial asthma rests on a diversity of experimental evidence. The recent physiopathological approaches raise the hope of new therapeutic avenues in the treatment of asthma.

Topics: Asthma; Humans; Leukotriene B4; SRS-A

Topics: Animals; Asthma; Bronchi; Bronchitis; Humans; Leukotriene B4; Neutrophils; Ozone; Prostaglandin-Endoperoxide Synthases

It is now recognized that, in addition to the preformed mast cell granule mediators, newly generated lipid compounds are likely to be exceedingly important in the mediation of allergic asthma and other atopic diseases. That the initiating event in allergic diseases evokes a far more complex set of biochemical events than those that only lead directly to the release of histamine and other preformed mediators, and that the functional efficacies of the leukotrienes, PGD2, and PAF are significant for allergic pathobiology mandate that the latter compounds will necessarily be subject to efforts for future therapeutic intervention in allergic patient populations.

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Asthma; Cricetinae; Humans; Hypersensitivity; Leukotriene B4; Lipid Bilayers; Lung; Mast Cells; Mice; Receptors, Leukotriene; Receptors, Prostaglandin; Skin; SRS-A

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Asthma; Cell Movement; Cytoplasmic Granules; Heparin; Histamine; Humans; Inflammation; Leukotriene B4; Mast Cells; Neutrophils; Prostaglandin D2; Prostaglandins D; Rats; SRS-A

The leukotrienes (LTs) are a novel group of biologically active mediators derived from arachidonic acid via lipoxygenase enzymes. LTB4 is a potent chemotactic agent for polymorphonuclear leukocytes and in vivo may mediate inflammatory reactions by inducing leukocyte recruitment by mediating indirectly vascular permeability charges and by modulating pain responses. LTC4 and LTD4 collectively account for the biological activity known as slow-reacting substance of anaphylaxis and are potent smooth muscle contracting agents. They may mediate inflammatory reactions by producing changes in blood flow and increases in vascular permeability. Evidence for LT involvement in a number of pathological conditions including diseases such as asthma, psoriasis, ulcerative colitis, and gout is now accumulating.

Topics: Animals; Arthritis, Rheumatoid; Asthma; Colitis, Ulcerative; Gout; Humans; In Vitro Techniques; Inflammation; Leukotriene B4; Neutrophils; Psoriasis; Rabbits; SRS-A

Topics: Animals; Arachidonic Acids; Asthma; Bronchi; Capillary Permeability; Guinea Pigs; Humans; In Vitro Techniques; Leukotriene B4; Mice; Mucus; Muscle Contraction; Muscle, Smooth; Peptides; Prostaglandins; Rabbits; Rats; SRS-A; Thromboxanes

The role of eicosanoids in the excessive secretion of respiratory mucous glycoproteins (MGP) accompanying immediate hypersensitivity and inflammatory pulmonary states has only been addressed in the last few years. Three lines of evidence suggest that eicosanoids may participate in the physiologic regulation of MGP secretion as well as being capable of stimulating increased MGP production. First, inhibition of eicosanoid generation with corticosteroids or eicosatetraynoic acid (ETYA) reduces ongoing baseline MGP secretion while selective inhibition of prostaglandin production with nonsteroidal anti-inflammatory agents increases MGP release. Second, arachidonic acid and a variety of eicosanoids stimulate MGP secretion in vitro. In fact, several lipoxygenase pathway metabolites including hydroxyeicosatetraenoic acids (HETEs) and leukotrienes (LTC4 and LTD4) significantly increase MGP secretion in nanogram quantities. Third, a variety of pulmonary cells including airway epithelium, endothelial cells, mast cells, alveolar macrophages and neutrophilic leukocytes generate eicosanoids under conditions that would be encountered in clinical states in which mucus secretion occurs. Thus, mucus secretion during both normal and stimulated states would be influenced by eicosanoids. It seems likely that this eicosanoid-mucus secretion relationship is very important in all forms of asthma, but most particularly in aspirin-related asthma.

Topics: Animals; Arachidonic Acids; Aspirin; Asthma; Bronchial Diseases; Cells, Cultured; Fatty Acids, Unsaturated; Humans; Leukotriene B4; Leukotrienes; Mucoproteins; Mucus; Prostaglandins; Thromboxanes

Topics: Animals; Arteries; Asthma; Biological Assay; Humans; Immune System Diseases; Inflammation; Leukotriene B4; Lung; Muscle, Smooth; SRS-A; Structure-Activity Relationship

Recent advances in biochemistry and cell biology have allowed the determination of the structure and biosynthetic pathways of the leukotriene constituents of slow-reacting substance of anaphylaxis. The sulphidopeptide leukotrienes have potent biological actions including effects on smooth muscle, mucus secretion and vascular permeability whereas leukotriene B3 is a powerful chemoattractant for neutrophils. It seems likely that the biological activities of the leukotrienes make a substantial contribution to the pathogenesis of asthma and that research directed towards the development of antagonists or inhibitors of leukotriene synthesis may lead to a major therapeutic advance.

Topics: Airway Resistance; Animals; Asthma; Bronchi; Chemical Phenomena; Chemistry; Hemodynamics; Humans; In Vitro Techniques; Leukotriene B4; Lung; Lung Compliance; Mucus; Muscle, Smooth; Neutrophils; SRS-A

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Aspirin; Asthma; Bronchitis; Dinoprost; Dinoprostone; Epoprostenol; Humans; Leukotriene B4; Lung; Lung Diseases; Prostaglandin D2; Prostaglandin Endoperoxides, Synthetic; Prostaglandin H2; Prostaglandins D; Prostaglandins E; Prostaglandins F; Prostaglandins G; Prostaglandins H; Pulmonary Circulation; Pulmonary Ventilation; SRS-A

Topics: Animals; Asthma; Bronchi; Eicosanoic Acids; Humans; Leukotriene B4; Lung; Prostaglandins; Prostanoic Acids; SRS-A; Thromboxanes

Corticosteroids are useful in the treatment of both allergic and idiosyncratic asthma. Although the mechanisms of corticosteroid action in asthma are poorly understood, several possible sites of action have been proposed. Corticosteroids alter the cellular and vascular inflammatory response to bronchial injury, affect catecholamine action on airways, and alter the production of eicosanoids, all of which aid in the resolution of bronchospasm in asthmatic patients. Corticosteroids should only be used for the treatment of asthma after therapeutic levels of methylxanthines and beta agonists have been achieved. Although the optimal doses of corticosteroids in asthma have not been defined, guidelines exist to aid in therapy. In the treatment of status asthmaticus, the intravenous route of administration is preferable. Short courses of corticosteroids may be useful in the treatment of chronic asthma. When long-term corticosteroid therapy is the only option for control of bronchospasm, alternate-day and/or aerosolized corticosteroids are preferable to daily corticosteroids and are associated with fewer side effects. Corticosteroids are useful in the pregnant asthmatic patient when bronchospasm cannot be controlled with bronchodilators. The major risk to the fetus in pregnant asthmatics is hypoxia from uncontrolled bronchospasm, and not from therapy. However, the lowest possible dose of systemic corticosteroids needed to control symptoms, with or without the use of aerosolized corticosteroids, is recommended. All asthmatics who have needed systemic or aerosolized corticosteroids within 6 months prior to surgery should receive preoperative and post-operative corticosteroid therapy. For patients not usually on systemic corticosteroids, conversion to oral prednisone, with a rapid taper is recommended. Side effects from short-term corticosteroid therapy are minimal, with hyperglycemia and psychosis being the major concerns. Long-term steroid therapy has significant side effects, however, and use should be minimized. Suppression of the HPA axis is one of the most potentially dangerous side effects of corticosteroids, and therefore any patient who has been treated with corticosteroids for longer than 4 weeks should be evaluated for possible adrenal suppression.

Topics: Adrenergic beta-Agonists; Asthma; Autonomic Nervous System; Eicosanoic Acids; Female; Glucocorticoids; Humans; Hypothalamo-Hypophyseal System; Immunoglobulin E; Leukocytes; Leukotriene B4; Male; Pituitary-Adrenal System; Pregnancy; Pregnancy Complications; Prostaglandins; SRS-A; Status Asthmaticus; Substance Withdrawal Syndrome; Surgical Procedures, Operative; Thromboxanes

Leukotrienes are released in inflammatory and immediate hypersensitivity reactions. Leukotrienes are novel metabolites of arachidonic acid produced by the lungs and leucocytes. Their formation is catalyzed by a specific 5-lipoxygenase. The key compound of this pathway is leukotriene A4 which is transformed either into leukotriene B4 by enzymatic hydrolysis or into leukotriene C4 by addition of glutathione. Leukotriene D4 and E4, as well as their precursor leukotriene C4, are the myotropic constituents of the "Slow Reacting Substance of Anaphylaxis" (SRS-A). Leukotrienes are potent bronchoconstrictors in vitro and in vivo. They induce the production of mucus by the respiratory tract and decrease its transport. Leukotrienes (chiefly leukotrienes C4, D4 and E4) induce the vasoconstriction of large vessels and capillaries. Leukotriene B4 stimulates several leukocyte functions related to inflammation (chemotaxis, aggregation, release of lysosomal enzymes and production of superoxide anion). In addition, it induces the formation of suppressive and cytotoxic T-Lymphocytes. The actions of leukotrienes are mediated by specific receptors and, in certain organs, their mechanism of action involves a stimulation of the formation of prostaglandins and thromboxanes. Non-steroidal antiinflammatory drugs (aspirin) inhibit the biosynthesis of prostaglandins and thromboxanes, whereas steroidal antiinflammatory agents (dexamethasone) should inhibit the production of leukotrienes as well as of prostaglandins and thromboxanes (through an indirect action on phospholipase A2).

Topics: Animals; Arachidonic Acids; Asthma; Blood Vessels; Cromolyn Sodium; Heart; Humans; Inflammation; Leukocytes; Leukotriene B4; Respiratory Physiological Phenomena; Respiratory System; SRS-A

Leukotrienes (LTs) are generated from human and guinea-pig lung tissue during antigen challenge. Both human and guinea-pig lung generate LTD4, LTC4, and LTE4 are also formed by human lung and LTB4, by guinea-pig lung. LTC4, LTD4, and LTE4 contract guinea-pig trachea and human bronchus, LTC4 and LTD4 being very much more active than histamine. LTB4 shows some activity but rapidly develops tachyphylaxis. In preparations of guinea-pig lung (perfused lung and parenchymal strips) all LTs cause stimulation of a phospholipase and release of thromboxane A2 (TxA2) and other cyclo-oxygenase products. TxA2 is bronchoconstrictor and augments the LT-induced contractions of guinea-pig parenchyma. Contractions of parenchyma are inhibited by indomethacin, carboxyheptylimidazole or mepacrine. LTs are much less active in contracting parenchymal tissue from human, rat or rabbit and there is no evidence of LT-induced release of TxA2 in these tissues. Since LTC4 and LTD4 cause coronary vasoconstriction in guinea-pig or rat isolated hearts and greyhounds in vivo, LTs generated in lung during antigen challenge may contribute to anaphylactic cardiac depression. LTC4 and LTD4 cause vasoconstriction in guinea-pig skin and constrict guinea-pig pulmonary artery. Recently we have shown that LTs are generated from selected arteries by immunological and non-immunological stimulation. Pulmonary (pig, human, guinea-pig) and coronary arteries (pig) produced the highest concentration of LTD4-like material. The generation of LTs by and their possible actions on the pulmonary circulation may be important in respiratory disease. LTs, B4, C4, D4 cause exudation of plasma (sometimes potentiated by prostaglandins) in the skin of various species. If LTs have similar actions in the lung they may contribute to oedema of the airways. LTC4 is a weak stimulator of mucin secretion in cat trachea but may synergise with prostaglandins released in allergic conditions.

Topics: Animals; Asthma; Bronchi; Coronary Vessels; Guinea Pigs; Humans; In Vitro Techniques; Leukotriene B4; Leukotriene E4; Mucins; Muscle Contraction; Rats; SRS-A; Trachea

Topics: 5,8,11,14-Eicosatetraynoic Acid; Anaphylaxis; Asthma; Bronchi; Bronchial Spasm; Fatty Acids, Unsaturated; Humans; Leukotriene B4; Lipoxygenase; Muscle, Smooth; SRS-A

The family of eicasanoids, biologically active metabolites of polyunsaturated C20 fatty acids such as arachidonic acid, has recently been enlarged by the recognition of a new biosynthetic pathway leading to the leukotrienes, including the compounds described two decades ago as 'slow reacting substances'. These biologically potent substances are involved in regulation of the immune response and also as mediators in various disease states. This account presents a brief history of this field, an overview of the biological relevance of leukotrienes, and a discussion of the investigations which led to the clarification of the molecular structures, pathway of biosynthesis and total chemical synthesis of the leukotrienes, including leukotrienes A, B, C, D and E (LTA-LTE). As a result of the synthetic work these rare substances are available for the first time in pure form and in quantities sufficient for biological and medical studies. Also reviewed are recent discoveries with regard to the development of inhibitors of leukotriene biosynthesis and anti-leukotrienes.

Topics: Animals; Arachidonic Acids; Asthma; Autacoids; Chemical Phenomena; Chemistry; Humans; Hydroxyeicosatetraenoic Acids; Hypersensitivity; Leukotriene A4; Leukotriene B4; Leukotriene E4; Leukotrienes; Lipoxygenase Inhibitors; Macrophages; Mast Cells; Molecular Conformation; Neutrophils; SRS-A; Stereoisomerism; Structure-Activity Relationship

Immunological and non-immunological injury induce as a result of the action of the enzyme lipoxygenase the release of a series of arachidonic acid metabolites known as leukotrienes. The leukotrienes play an important role in allergic and inflammatory disease. Leukotrienes C4, D4 and E4 which recently have been recognized as constituents of the allergic mediator slow reacting substance of anaphylaxis (SRS-A) induce powerful bronchoconstriction, plasma exudation and weal and flare responses. Leukotriene B4 is involved in the regulation of chemotaxis, chemokinesis and other aspects of both cellular and vascular inflammation. The development of specific lipoxygenase inhibitors may lead to a new class of drugs for the treatment of bronchial asthma and chronic inflammatory diseases.

Topics: Arachidonic Acids; Asthma; Biotransformation; Chemotaxis, Leukocyte; Humans; Hypersensitivity; Inflammation; Leukotriene A4; Leukotriene B4; Leukotriene E4; Lipoxygenase; Lipoxygenase Inhibitors; Neutrophils; SRS-A

Topics: Asthma; Catecholamines; Humans; Leukotriene B4; Prostaglandins; Respiratory Hypersensitivity; SRS-A; Sympathetic Nervous System

Leukotriene B4 (LTB4) is a chemotactic mediator implicated in the pathogenesis of asthma. JNJ-40929837 is an oral inhibitor of LTA4 hydrolase, which catalyzes LTB4 production. We evaluated the effects of JNJ-40929837 in a human bronchial allergen challenge (BAC) model. In this double-blind, 3-period crossover study, 22 patients with mild, atopic asthma were randomized to one of three treatments per period: 100 mg/day JNJ-40929837 for 6 days followed by 50 mg/day on day 7; 10 mg/day montelukast for 6 days; and matched placebo. The BAC was performed on day 6 of each treatment period. Primary outcome was BAC-induced late asthmatic response (LAR) measured by maximal percent reduction in forced expiratory volume (FEV1) in one second. Secondary outcomes included early asthmatic response (EAR) by maximal percent reduction in FEV1, EAR and LAR evaluated by area under the FEV1/time curve (AUC0-2, AUC3-10, respectively), change in baseline FEV1 after 5-day treatment, safety, and correlation of JNJ-40929837 to the divalent cation ionophore A23187-stimulated whole blood LTB4 levels and sputum basal LTB4 levels. No significant differences were observed in the primary or secondary FEV1 endpoints with JNJ-40929837 versus placebo. Compared with placebo (n = 17, LS mean = 27.7), there was no significant attenuation of the maximal percent reduction in the LAR FEV1 with JNJ-40929837 (n = 16, LS mean = 28.6, P = 0.63) but montelukast (n = 17, LS mean = 22.6, P = 0.01) significantly attenuated the LAR. JNJ-40929837 substantially inhibited LTB4 production in whole blood, decreased sputum LTB4 levels and was well-tolerated. The number of adverse events leading to study withdrawal was the same in JNJ-40929837 and placebo groups. In conclusion, JNJ-40929837 demonstrated target engagement in blood and sputum. No significant impact in response to allergen inhalation was observed with JNJ-40929837 versus placebo.. This study is registered at ClinicalTrials.gov: NCT01241422.

Topics: Acetates; Adult; Anti-Asthmatic Agents; Asthma; Bronchial Provocation Tests; Cross-Over Studies; Cyclopropanes; Double-Blind Method; Epoxide Hydrolases; Female; Forced Expiratory Volume; Humans; Leukotriene B4; Male; Quinolines; Sputum; Sulfides; Thiazoles; Treatment Outcome; Tropanes; Young Adult

Inhaled allergen challenge is a standard method to study airway responses to inflammatory provocation and evaluate the therapeutic potential of novel anti-inflammatory compounds in asthma. MEM 1414 is a novel oral PDE4 inhibitor with high affinity and selectivity creating the potential for an improved side effect profile vs non-selective PDE inhibitors. We evaluated the tolerability and effect of MEM 1414 on airway responses in mild asthmatics.. A randomised double blind placebo controlled cross over study in two centres, in which sixteen steroid naïve atopic asthmatics were challenged with inhaled allergen. Subjects were dosed with MEM 1414 (600 mg) or placebo, twice daily orally for 7 days. Allergen challenge was performed on day 6 (2 hours post-dose), and methacholine responsiveness was measured 24 hours post allergen (day 7). Biomarkers of drug effects using ex vivo LPS stimulation of whole blood production of interleukin (IL)-6 and leukotriene (LT)-B4 and fractional exhaled nitric oxide (FeNO) were measured on day 6 (0, 2 and 8 hours post-dose). Plasma pharmacokinetics were measured on days 1, 6 and 7. The primary endpoint was the effect on late asthmatic response to allergen.. Treatment with MEM 1414 abrogated the late phase response with a mean difference in FEV1 (LAR 3-10 hours) of 104 ml (25%) vs placebo (p < 0.005), with no effect on the early response. Biomarker responses were also attenuated with MEM 1414 treatment with reductions in LPS-stimulated whole blood assays for TNFα at 8 hours (p < 0.03) and LTB4 at 24 hours (p = 0.0808) with no change in the IL-6 response. The MEM 1414 treatment phase was associated with higher incidence of nausea (6/16 MEM 1414 vs 2/16 placebo) and vomiting (3/16 vs 0/16 placebo).. Oral MEM 1414, a novel PDE4 inhibitor, significantly reduces the late response following inhaled allergen challenge. MEM 1414 also inhibited whole blood assays of cytokine production from inflammatory cells. MEM 1414 was associated with a typical adverse event profile of PDE4 inhibitors, namely nausea and vomiting although these were mild side effects.. Current controlled trials ISRCTN48047493.

Topics: Administration, Oral; Adolescent; Adult; Allergens; Asthma; Breath Tests; Bronchial Provocation Tests; Cells, Cultured; Female; Forced Expiratory Volume; Humans; Interleukin-6; Leukotriene B4; Lipopolysaccharides; Male; Middle Aged; Nausea; Nitric Oxide; Phosphodiesterase 4 Inhibitors; Time Factors; Tumor Necrosis Factor-alpha; Vomiting; Young Adult

GSK2190915, a potent 5-lipoxygenase-activating protein inhibitor, prevents the synthesis of leukotrienes and 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE).. To assess the effect of GSK2190915 on the allergen-induced asthmatic responses.. Nineteen eligible male subjects with mild asthma were enrolled in and completed this four-centre, double-blind, two-way crossover study (ClinicalTrials.gov NCT00748306). Subjects took GSK2190915 100 mg and placebo orally once daily for 5 days in randomized order. On Day 1 and 4 they had a methacholine challenge, on Day 3 they had an inhaled allergen challenge, and on Days 4 and 6 they had sputum induction.. GSK2190915 attenuated the early (0-2 h) and late (4-10 h) asthmatic responses to inhaled allergen compared with placebo. There was a statistically significant attenuation of the early asthmatic response (EAR) by GSK2190915; treatment difference of GSK2190915 vs. placebo for the minimum FEV(1) EAR was 0.408 L (0.205, 0.611). There was a statistically significant attenuation of the late asthmatic response (LAR) by GSK2190915; the treatment difference of GSK2190915 vs. placebo for the minimum FEV(1) LAR was 0.229 L (0.041, 0.417). There was a statistically significant attenuation of allergen-induced sputum eosinophil count on Day 4 following GSK2190915: mean treatment difference (95% CI) between GSK2190915 and placebo was -9.95% (-18.15%, -1.77%). Compared with placebo, GSK2190915 100 mg reduced median sputum LTB(4) by > 90% on Days 4 and 6. There was no effect on methacholine PC(20) post allergen. GSK2190915 was generally well tolerated.. GSK2190915 shows potential as a treatment for patients with asthma.

Topics: 5-Lipoxygenase-Activating Protein Inhibitors; Adult; Allergens; Asthma; Bronchial Provocation Tests; Humans; Indoles; Leukotriene B4; Male; Pentanoic Acids; Respiratory Function Tests; Sputum; Treatment Outcome; Young Adult

Leukotriene B4 (LTB(4)) is a potent inflammatory mediator in asthma, and is increased in more severe asthma. Targeting LTB(4), in addition to cysteinyl leukotrienes, could be beneficial in asthma. This was a randomized, double-blind trial of once-daily MK-0633, a potent 5-lypoxygenase inhibitor, 10 mg, 50 mg, and 100 mg, and placebo in patients 18-70 years with a history of chronic asthma, and FEV(1) ≥45 and ≤85% predicted. There was a 6-week main period and optional 18-week and 34-week periods (52 weeks total), the latter two comparing only MK-0633 100 mg and placebo. The primary endpoint was the change from baseline in FEV(1) over the last 4 weeks of the 6-week primary treatment period. Secondary endpoints included symptom scores, β-agonist use, peak expiratory flow (PEF), asthma quality of life questionnaire (AQLQ), asthma control questionnaire (ACQ), asthma attacks, exacerbations, days with asthma control, post-β-agonist FEV(1), and blood eosinophils. MK-0633 100 mg was significantly more effective than placebo for the change from baseline in FEV(1) (0.20 L vs. 0.13 L; p = 0.004). The other MK-0633 doses were not significantly more effective than placebo. MK-0633 (at various doses) was also more effective than placebo for β-agonist use, AQLQ, AM and PM PEFR, ACQ, and post-β-agonist FEV(1) (p < 0.05 for all). MK-0633 was associated with a dose-dependent increase in elevated aspartate aminotransferase and alanine aminotransferase. Because of the relative benefit-risk ratio, the optional study periods were terminated after unblinding for the main study period. Overall, the benefit-risk ratio did not support the clinical utility of MK-0633 in asthma.

Topics: Adolescent; Adult; Aged; Asthma; Benzenesulfonates; Benzopyrans; Chronic Disease; Disease Progression; Double-Blind Method; Female; Forced Expiratory Volume; Humans; Leukotriene B4; Lipoxygenase Inhibitors; Male; Middle Aged; Oxadiazoles; Spirometry; Treatment Outcome; Young Adult

Asthma can have a negative impact on quality of life although this is not well correlated with objective evaluations of pulmonary function. A medical food, EFF1009, containing the fatty acids gamma-linolenic acid (GLA) and eicosapentaenoic acid (EPA) decreases leukotriene B(4) synthesis in patients with asthma. Two previous clinical studies with EFF1009 provided preliminary evidence that the medical food improves asthma-related quality of life (ARQOL) and asthma management.. To evaluate the impact on ARQOL of EFF1009 in adults with asthma.. The study was a randomized, prospective, double-blind, placebo-controlled, parallel group study in twenty-one (N = 21 evaluable) subjects with mild to moderate persistent asthma who consumed the medical food emulsion or placebo emulsion daily for 28 days. All participants continued their asthma medications throughout the study. ARQOL, including asthma signs and symptoms, and asthma control were measured using the Mini Asthma Quality of Life Questionnaire (MiniAQLQ) and the Asthma Control Questionnaire (ACQ), administered at baseline, Day 14 and Day 28. Safety and tolerability parameters, including adverse events, were monitored.. Baseline ARQOL scores, forced expiratory volume in one second (FEV(1)) and other characteristics were balanced between both groups. Mean (standard error) total MiniAQLQ scores changed by 0.73 (0.38) and -0.22 (0.36) in the EFF1009 and placebo groups, respectively, (p < 0.05). The MiniAQLQ symptom domain score was improved in the EFF1009 group (p < 0.05). Total scores for the ACQ were not significantly improved in either group. Levels of the fatty acid EPA in plasma increased in the EFF1009 group but not the placebo group (p < 0.03). The medical food was well tolerated and no safety concerns were identified.. The dietary addition of the medical food EFF1009 to asthma management regimens can improve patient perceived, ARQOL and can also improve asthma management as evidenced by reduced asthma symptoms. An additional study of the medical food, with larger subject population and longer treatment duration, is warranted to confirm these findings.

Topics: Adult; Asthma; Double-Blind Method; Eicosapentaenoic Acid; Emulsions; Female; Food, Fortified; gamma-Linolenic Acid; Humans; Leukotriene B4; Male; Placebos; Plant Oils; Quality of Life; Surveys and Questionnaires; Treatment Outcome; Young Adult

Exhaled breath condensate analysis is an attractive but still not fully standardised method for investigating airway pathology. Adherence of biomarkers to various condensing surfaces and changes in condensing temperature has been considered to be responsible for the variability of the results. Our aims were to compare the efficacy of different types of condensers and to test the influence of condensing temperature on condensate composition.. Breath condensates from 12 healthy persons were collected in two settings: (1) by using three condensers of different type (EcoScreen, R-Tube, Anacon) and (2) by using R-Tube condenser either cooled to -20 or -70 degrees C. Condensate pH at standardised CO(2) level was determined; protein content was measured by the Bradford method and leukotrienes by EIA.. Breath condensates collected using EcoScreen were more alkaline (6.45+/-0.20 vs. 6.19+/-0.23, p<0.05 and 6.10+/-0.26, p<0.001) and contained more protein (3.89+/-2.03 vs. 2.65+/-1.98, n.s. and 1.88+/-1.99 microg/ml, p<0.004) as compared to the other devices. Only parameters obtained with R-Tube and Anacon correlated. Condensing temperature affected condensate pH (5.99+/-0.20 at -20 degrees C and 5.82+/-0.07 at -70 degrees C, p<0.05) but not protein content. Leukotriene B(4) was not found in any sample and cysteinyl-leukotriene was not found in condensates collected with R-Tube or Anacon.. Condenser type influences sample pH, total protein content and cysteinyl-leukotriene concentration. Condensing temperature influences condensate pH but not total protein content. These results suggest that adherence of the biomarkers to condenser surface and condensing temperature may play a role but does not fully explain the variability of EBC biomarker levels.

Topics: Adult; Asthma; Biomarkers; Breath Tests; Bronchoconstriction; Cysteine; Equipment Design; Exhalation; Female; Humans; Hydrogen-Ion Concentration; Leukotriene B4; Leukotrienes; Male; Middle Aged; Proteins; Statistics, Nonparametric; Temperature

We have developed a method for measuring leukotriene B4 glucuronide, a marker of systemic leukotriene B4 biosynthesis, in human urine. This method involves the separation of two positional isomers of leukotriene B4 glucuronide by high-performance liquid chromatography, followed by hydrolysis with beta-glucuronidase and then leukotriene B4 quantification by enzyme immunoassay after purification by high-performance liquid chromatography. One of two positional isomers of leukotriene B4 glucuronide was predominantly present in urine. The concentration of the isomer increased in urine from aspirin-intolerant asthma patients after aspirin challenge. Urinary leukotriene E4 and leukotriene B4 glucuronide concentrations in 13 normal healthy adults were 94.6 pg/mg-creatinine (median) and 22.3 pg/mg-creatinine, respectively. Urinary LTE4 concentration increased during the first 3h after allergen inhalation in atopic patients. However, allergen-induced bronchoconstriction was not associated with an increased concentration of LTB4 glucuronide in urine. The method enabled us to precisely determine urinary leukotriene B4 glucuronide concentration.

Topics: Adult; Aged; Asthma; Bleeding Time; Bronchial Provocation Tests; Chromatography, High Pressure Liquid; Female; Glucuronidase; Glucuronides; Humans; Hydrolysis; Immunoenzyme Techniques; Isomerism; Kinetics; Leukotriene B4; Leukotriene E4; Male; Microsomes, Liver; Middle Aged; Time Factors

Previous research has demonstrated that fish oil supplementation has a protective effect on exercise-induced bronchoconstriction (EIB) in elite athletes, which may be attributed to its antiinflammatory properties. Since EIB in asthma involves proinflammatory mediator release, it is feasible that fish oil supplementation may reduce the severity of EIB in asthmatic subjects.. To determine the efficacy of fish oil supplementation on severity of EIB in subjects with asthma.. Randomized, double-blind, crossover study.. Lung function and exercise testing in a university research laboratory.. Sixteen asthmatic patients with documented EIB entered the study on their normal diet and then received either fish oil capsules containing 3.2 g of eicosapentaenoic acid and 2.0 g of docohexaenoic acid (fish oil diet, n = 8) or placebo capsules (placebo diet, n = 8) daily for 3 weeks. At the beginning of the study (normal diet) and at the end of each treatment phase, the following pre-exercise and postexercise measures were assessed: (1) pulmonary function; (2) induced sputum differential cell count percentage and proinflammatory eicosanoid metabolite (leukotriene C4 [LTC4]-leukotriene E4 [LTE4] and prostaglandin D2 [PGD2]) and cytokine (interleukin [IL]-1beta and tumor necrosis factor [TNF]-alpha) concentrations; and (3) eicosanoid metabolites leukotriene B4 (LTB4) and leukotriene B5 (LTB(5)) generation from activated polymorphonuclear leukocytes (PMNLs).. On the normal and placebo diet, subjects exhibited EIB. However, the fish oil diet improved pulmonary function to below the diagnostic EIB threshold, with a concurrent reduction in bronchodilator use. Induced sputum differential cell count percentage and concentrations of LTC4-LTE4, PGD2, IL-1beta, and TNF-alpha were significantly reduced before and following exercise on the fish oil diet compared to the normal and placebo diets. There was a significant reduction in LTB4 and a significant increase in LTB5 generation from activated PMNLs on the fish oil diet compared to the normal and placebo diets.. Our data suggest that fish oil supplementation may represent a potentially beneficial nonpharmacologic intervention for asthmatic subjects with EIB.

Topics: Adult; Asthma; Bronchoconstriction; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Eicosapentaenoic Acid; Exercise Test; Female; Fish Oils; Follow-Up Studies; Forced Expiratory Volume; Humans; Leukocyte Count; Leukotriene B4; Male; Sputum; Treatment Outcome

Airway hyperresponsiveness and inflammation can be noninvasively studied by bronchial provocation using direct (histamine) or indirect (adenosine 5'-monophosphate [AMP]) stimuli and induced sputum.. To report on the immediate effects of histamine and AMP challenge on induced sputum neutrophil counts and related mediator levels.. We performed a single-masked, randomized, placebo-controlled, 3-way, crossover, methodological study in 14 atopic patients (median age, 25 years; 8 males; mean +/- SD forced expiratory volume in 1 second, 99% +/- 5%) without anti-inflammatory medication use. At baseline, sputum induction was performed. Bronchial challenges with AMP, histamine, or placebo were performed 48 hours later. Thirty minutes after challenge, sputum induction was performed again. Challenge periods in each patient were separated by more than 2 weeks. Sputum cells and the mediators leukotriene B4, interleukin 8, myeloperoxidase, and albumin were quantified.. Comparing median challenge-induced relative changes in cells and mediators, neither histamine nor AMP challenge altered the induced sputum neutrophil counts (histamine, 2.7%; AMP, 2.95%; placebo, -2%; P > .07 for all), interleukin 8 levels (histamine, 2.4 ng/mL; AMP, -3.8 ng/mL; placebo, -0.2 ng/mL; P > .06), leukotriene B4 levels (histamine, -4.8 pg/mL; AMP, 3 pg/mL; placebo, 6 pg/mL; P > .08), or myeloperoxidase levels (histamine, 0.16 microg/mL; AMP, 0 microg/mL; placebo, -0.03 microg/mL; P > .07). Sputum albumin levels were increased after histamine challenge compared with AMP and placebo challenge (P < .01 for both).. Histamine and AMP provocation have no major effects on induced neutrophil counts and related mediator levels in atopic patients, whereas histamine challenge induces plasma leakage. Potential interactions of noninvasive methods to evaluate airway reactivity and inflammation should be carefully considered.

Topics: Adenosine Monophosphate; Adult; Asthma; Bronchial Provocation Tests; Cell Count; Cross-Over Studies; Female; Histamine; Humans; Interleukin-8; Leukotriene B4; Male; Neutrophils; Peroxidase; Rhinitis, Allergic, Seasonal; Sputum

The role of leukotriene (LT) B4, a potent inflammatory mediator, in atopic asthmatic and atopic nonasthmatic children is largely unknown. The lack of a gold standard technique for measuring LTB4 in exhaled breath condensate (EBC) has hampered its quantitative assessment in this biological fluid. We sought to measure LTB4 in EBC in atopic asthmatic children and atopic nonasthmatic children. Exhaled nitric oxide (NO) was measured as an independent marker of airway inflammation.. Fifteen healthy children, 20 atopic nonasthmatic children, 25 steroid-naïve atopic asthmatic children, and 22 atopic asthmatic children receiving inhaled corticosteroids were studied. The study design was of cross-sectional type. Exhaled LTB4 concentrations were measured using liquid chromatography/mass spectrometry-mass spectrometry (LC/MS/MS) with a triple quadrupole mass spectrometer. Exhaled NO was measured by chemiluminescence with a single breath on-line method. LTB4 values were expressed as the total amount (in pg) of eicosanoid expired in the 15-minute breath test. Kruskal-Wallis test was used to compare groups.. Compared with healthy children [87.5 (82.5-102.5) pg, median and interquartile range], exhaled LTB4 was increased in steroid-naïve atopic asthmatic [255.1 (175.0-314.7) pg, p < 0.001], but not in atopic nonasthmatic children [96.5 (87.3-102.5) pg, p = 0.59)]. Asthmatic children who were receiving inhaled corticosteroids had lower concentrations of exhaled LTB4 than steroid-naïve asthmatics [125.0 (25.0-245.0) pg vs 255.1 (175.0-314.7) pg, p < 0.01, respectively]. Exhaled NO was higher in atopic nonasthmatic children [16.2 (13.5-22.4) ppb, p < 0.05] and, to a greater extent, in atopic steroid-naïve asthmatic children [37.0 (31.7-57.6) ppb, p < 0.001] than in healthy children [8.3 (6.1-9.9) ppb]. Compared with steroid-naïve asthmatic children, exhaled NO levels were reduced in asthmatic children who were receiving inhaled corticosteroids [15.9 (11.5-31.7) ppb, p < 0.01].. In contrast to exhaled NO concentrations, exhaled LTB4 values are selectively elevated in steroid-naïve atopic asthmatic children, but not in atopic nonasthmatic children. Although placebo control studies are warranted, inhaled corticosteroids seem to reduce exhaled LTB4 in asthmatic children. LC/MS/MS analysis of exhaled LTB4 might provide a non-invasive, sensitive, and quantitative method for airway inflammation assessment in asthmatic children.

Topics: Asthma; Biomarkers; Breath Tests; Child; Chromatography, Liquid; Cross-Sectional Studies; Exhalation; Female; Humans; Leukotriene B4; Male; Mass Spectrometry; Nitric Oxide

Dietary gammalinolenic acid (GLA), a potent inhibitor of 5-lipoxygenase (5-LOX) and suppressor of leukotriene B4 (LTB4), can attenuate the clinical course of rheumatoid arthritics, with negligible side effects. Since Zileuton, also an inhibitor of 5-LOX, attenuates asthma but with an undesirable side effect, we investigated whether dietary GLA would suppress biosynthesis of PMN-LTB4 isolated from asthma patients and attenuate asthma. Twenty-four mild-moderate asthma patients (16-75 years) were randomized to receive either 2.0 g daily GLA (borage oil) or corn oil (placebo) for 12 months. Blood drawn at 3 months intervals was used to prepare sera for fatty acid analysis, PMNs for determining phospholipid fatty acids and for LTB4 generation. Patients were monitored by daily asthma scores, pulmonary function, and exhaled NO. Ingestion of daily GLA (i) increased DGLA (GLA metabolite) in PMN-phospholipids; (ii) increased generation of PMN-15-HETrE (5-LOX metabolite of DGLA). Increased PMN-DGLA/15-HETrE paralleled the decreased PMN generation of proinflammatory LTB4. However, the suppression of PMN-LTB4 did not reveal statistically significant suppression of the asthma scores evaluated. Nonetheless, the study demonstrated dietary fatty acid modulation of endogenous inflammatory mediators without side effects and thus warrant further explorations into the roles of GLA at higher doses, leukotrienes and asthma.

Topics: Adult; Aged; Arthritis, Rheumatoid; Asthma; Dietary Supplements; Double-Blind Method; Fatty Acids; Female; gamma-Linolenic Acid; Humans; Hydroxyurea; Leukotriene B4; Lipoxygenase Inhibitors; Male; Middle Aged; Neutrophils; Plant Oils; Prospective Studies

To evaluate the effects on signs and symptoms of a coexisting vernal keratoconjunctivitis in patients treated with oral montelukast sodium for asthma.. Twelve patients with vernal keratoconjunctivitis and asthma were enrolled in this pilot study. Topical eyedrops or any systemic treatment was discontinued for at least 7 days before montelukast treatment. Patients were asked to grade their ocular discomfort daily. The following signs and symptoms were also recorded and graded through medical examination at baseline,after 15 days of treatment, and 15 days after treatment discontinuation: physician-evaluated tarsal and bulbar papillae, hyperemia, secretion, and chemosis; and patient-evaluated itching, burning, tearing, photophobia, foreign body sensation, secretion, and redness. Peak expiratory flow rate at 8 AM was also recorded. Samples were collected at the same time points for enzyme-linked immunosorbent assay measurement of leukotriene B4 in tears and leukotriene E4 in urine.. Eight of the 10 patients evaluated reported a reduction in symptoms at the end of treatment. Montelukast treatment significantly decreased physician-rated hyperemia, secretion, and chemosis as well as patient-rated burning, tearing, photophobia, secretion, and redness. Effects persisted 15 days after discontinuation of treatment. Clinical changes were associated with a significant increase in leukotriene B4 in tears and a significant decrease in leukotriene E4 in urine after 15 days of treatment.. The significant and persistent reduction of ocular signs and symptoms in asthmatic patients with vernal keratoconjunctivitis treated for 15 days with montelukast strongly suggests the need for double-masked placebo-controlled trials to confirm the potential of this new treatment in vernal keratoconjunctivitis.

Topics: Acetates; Adolescent; Adult; Anti-Asthmatic Agents; Asthma; Child; Child, Preschool; Conjunctivitis, Allergic; Cyclopropanes; Enzyme-Linked Immunosorbent Assay; Female; Humans; Leukotriene Antagonists; Leukotriene B4; Leukotriene E4; Male; Ophthalmic Solutions; Peak Expiratory Flow Rate; Pilot Projects; Quinolines; Sulfides; Tears

Platelet-activating factor (PAF)-induced neutrophil lung sequestration may require cell surface adhesion molecules (macrophage-1 antigen (MAC-1) and lymphocyte function-associated antigen-1 (LFA-1)). In this randomised, double-blinded, crossover study, the neutrophil kinetics after PAF and Lyso-PAF (L-PAF) airway challenge were investigated in nine mild-intermittent asthmatics. Neutrophils were measured in peripheral blood (PB) before and at 5, 15, 45 and 240 min after bronchoprovocation, and in induced sputum before and at 240 min after challenge. MAC-1 and LFA-1 expression were assessed by immunocytochemistry, and leukotriene B4 (LTB4) was measured by enzyme-immunoassay in induced-sputum supernatants. Compared with baseline, neutrophils in PB decreased 5 min after PAF, while at 240 min neutrophils in induced sputum increased. Compared with baseline and L-PAF, PAF decreased the percentages of MAC-1- and LFA-1-positive neutrophils in PB at 5 min, but increased the percentages of MAC-1 and LFA-1 in neutrophil-induced sputum. Moreover, compared with baseline and L-PAF, PAF-induced sputum revealed higher LTB4 levels, a finding that correlated with the elevated number of neutrophils in induced sputum. These findings suggest that macrophage-1 antigen and lymphocyte function-associated antigen-1 are involved in platelet-activating factor-induced neutrophil lung traffic, and that this process is modulated by enhanced leukotriene B4 release within the airways.

Topics: Adult; Asthma; Cross-Over Studies; Double-Blind Method; Female; Humans; Inflammation Mediators; Leukotriene B4; Male; Neutrophils; Platelet Activating Factor; Receptors, Leukocyte-Adhesion; Sputum

The effects of perilla seed oil (n-3 fatty acids) on bronchial asthma were compared with the effects of corn oil (n-6 fatty acids) in relation to the pulmonary function and the generation of leukotriene B4 (LTB4) and C4 (LTC4) by leucocytes.. 14 asthmatic subjects were divided randomly into two groups: one group (7 subjects) consumed perilla seed oil-rich supplementation and the other group (7 subjects) consumed corn oil-rich supplementation for 4 weeks. Generation of LTs by leucocytes and respiratory function were compared between the two groups.. The generation of LTB4 and LTC4 by leucocytes tended to increase in subjects (N=7) with corn oil-rich supplementation, and decrease in subjects (N=7) with perilla seed oil-rich supplementation. Significant differences between the two groups were observed in the generation of LTB4 at 2 weeks (p<0.05) and LTC4 at 2 weeks (p<0.05) after dietary supplementation. Significant increases in the value of PEF (p<0.05), FVC (p<0.01), FEV(1.0) (p<0.05) and V(25) (p<0.05) were found in subjects who received perilla seed oil supplementation for 4 weeks. And significant differences in the value of FVC (p<0.05) and FEV(1.0) (p<0.05) were observed between the two groups after 4 weeks of dietary supplementation.. These results suggest that perilla seed oil-rich supplementation is useful for the treatment of asthma in terms of suppression of LTB4 and LTC4 generation by leucocytes, and improvement of pulmonary function.

Topics: Adult; Aged; Aged, 80 and over; alpha-Linolenic Acid; Asthma; Biomarkers; Corn Oil; Dietary Fats, Unsaturated; Dietary Supplements; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Female; Humans; Leukocytes; Leukotriene B4; Leukotriene C4; Male; Middle Aged; Plant Oils; Respiratory Function Tests; Treatment Outcome

Leukotrienes have been implicated in the bronchoconstriction caused by indirect stimuli. In the present study we examined the effect of oral ABT-761, a novel 5-lipoxygenase (5-LO) inhibitor, on exercise- and adenosine (AMP)-induced bronchoconstriction in nine asthmatics. At the four 1-d, single-dose treatment periods, ABT-761 (200 mg) or placebo (P) was ingested 5 h before challenge in a double-blind, crossover fashion. At study periods 1 and 2 the subjects performed an exercise challenge and at study periods 3 and 4 an AMP challenge. Pretreatment with ABT-761 caused a significant inhibition of the maximal percentage fall of FEV1 from baseline (p = 0.037) and a reduction of the percentage fall in FEV1 (area under the curve, AUC) of 61.4 +/- 14.1% (mean +/- SEM) after exercise challenge (p = 0.021). Although pretreatment with ABT-761 did not significantly inhibit the maximal fall of FEV1 after AMP challenge (p = 0.134), the overall bronchoconstriction was significantly inhibited, the AUC being reduced by a mean (+/- SEM) of 82.7 +/- 7.2% (p = 0.012). There was no significant correlation between the protective effect against exercise and that against AMP for individual patients. The percentage change in urinary leukotriene E4 (LTE4) excretion at exercise was + 18.1 +/- 10.9% on placebo and -44.8 +/- 6.2% after ABT-761 (p = 0.017); changes at adenosine were + 38.5 +/- 27.0% on placebo and -36.7 +/- 9.8% after ABT-761 (p = 0.028). On placebo, exercise produced a marked stimulation of the ex vivo LTB4 production, whereas adenosine was associated with only a minor increase; ABT-761 caused a greater than 90% inhibition (p < 0.05 for both challenges). We conclude that ABT-761 is a potent and long-acting 5-LO inhibitor which significantly attenuates exercise- and adenosine-induced bronchoconstriction, indicating that leukotrienes are important mediators in both challenges.

Topics: Adenosine; Adult; Asthma; Bronchi; Bronchial Provocation Tests; Bronchoconstriction; Cross-Over Studies; Double-Blind Method; Enzyme Inhibitors; Exercise; Female; Forced Expiratory Volume; Humans; Hydroxyurea; Leukotriene B4; Lipoxygenase Inhibitors; Male; Middle Aged; Vasodilator Agents

To determine the efficacy of salmeterol alone in a group of patients with moderate asthma with nocturnal worsening of symptoms.. Double-blind, randomized, placebo-controlled crossover study.. Tertiary care hospital specializing in respiratory diseases.. Ten patients with nocturnal asthma.. Subjects were randomized to salmeterol, 100 micrograms twice daily, or placebo for 6 weeks with a 1-week washout between treatment periods. Symptoms, nocturnal awakenings, and beta 2-agonist use were recorded daily. Spirometry was performed at weeks 1 and 6 of each period at bedtime and at 4 AM, and methacholine challenge was performed at 4 AM followed by bronchoscopy with BAL. BAL fluid analysis included cell count and differential count, eosinophil cationic protein, Charcot-Leyden crystal protein, leukotriene B4, and thromboxane B2.. The percentage of nights with awakenings decreased significantly with salmeterol (69.8 +/- 8.7% vs 30.6 +/- 10.8% for placebo and salmeterol, respectively; p = 0.02). The percentage of 24-h days with supplemental inhaled beta 2-agonist use significantly decreased with salmeterol (85.9 +/- 9.4% vs 70.4 +/- 10.1% for placebo and salmeterol, respectively; p = 0.04). There were no significant differences in bronchial reactivity, 4 AM FEV1, overnight percentage change in FEV1, or indexes of airway inflammation.. Salmeterol alone improves the number of nocturnal awakenings and supplemental 24-h beta 2-agonist use in nocturnal asthma without significantly altering lung function and airway inflammation.

Topics: Adrenergic beta-Agonists; Adult; Albuterol; Asthma; Blood Proteins; Bronchoalveolar Lavage Fluid; Bronchoconstrictor Agents; Bronchodilator Agents; Bronchoscopy; Cell Count; Circadian Rhythm; Cross-Over Studies; Double-Blind Method; Eosinophil Granule Proteins; Eosinophils; Female; Follow-Up Studies; Forced Expiratory Volume; Glycoproteins; Humans; Inflammation; Inflammation Mediators; Leukotriene B4; Lung; Lysophospholipase; Male; Methacholine Chloride; Placebos; Ribonucleases; Salmeterol Xinafoate; Sleep; Spirometry; Thromboxane B2

Leukotriene (LT) B4 is a potent leukocyte chemotaxin that increases bronchial responsiveness in animal models. In a double-blind, placebo-controlled crossover study we examined the effects of LTB4 on lung function, bronchial responsiveness, and blood leukocyte counts in six normal subjects and in six subjects with mild asthma who inhaled mean +/- SEM doses of 17.6 +/- 3.4 and 18.2 +/- 1.9 microg LTB4, respectively, or placebo. There were no significant changes in specific airway conductance or bronchial responsiveness in either normal subjects or asthmatics for as long as 24 h after inhalation. In the normal subjects, LTB4 rapidly reduced blood neutrophil counts to 19.8 +/- 6.3% of baseline at 5 min (p = 0.0003 compared with placebo), followed by a neutrophilia of 307 +/- 40% of baseline at 30 min (p = 0.007). Similar changes occurred in asthmatics, with a neutropenia at 5 min (69.6 +/- 5.8%; p = 0.003) and a neutrophilia at 30 min (183 +/- 17.2%; p = 0.037). The neutrophilia was not sustained in either subject group, with values being no different from that of placebo by 6 h. The asthmatics had significantly less neutropenia (p = 0.005) and less neutrophilia (p = 0.018) than did the normal subjects. Placebo inhalation had no effect on any parameter in either group. The smaller neutrophil responses in asthmatics may reflect desensitization of blood neutrophils in vivo because of chronic exposure to endogenous LTB4.

Topics: Administration, Inhalation; Adult; Airway Resistance; Asthma; Bronchial Provocation Tests; Cross-Over Studies; Double-Blind Method; Female; Histamine; Humans; Leukocyte Count; Leukotriene B4; Male; Neutrophils; Respiratory Mechanics

Leukotrienes have been implicated in the mediation of airway obstruction induced by hyperventilation of cold dry air in asthmatic subjects. The effect of a novel inhibitor of 5-lipoxygenase activating protein, BAYx 1005, on the bronchospastic response to cold dry air hyperventilation was investigated in asthmatic patients.. After a screening cold dry air hyperventilation challenge to document cold air responsiveness, 16 asthmatic subjects (baseline forced expiratory volume in one second (FEV1) > 60% of predicted) underwent cold air challenge three hours after receiving 750 mg of BAYx 1005 or placebo using a randomised, double blind, crossover design. Leukotriene synthesis inhibition was estimated by measuring the concentration of leukotriene B4 in whole blood stimulated with calcium ionophore A21387.. Treatment with BAYx 1005 produced a 34% (95% CI 11 to 63) increase in the amount of cold air minute ventilation required for a 10% decrease in FEV1 (PD10VE) compared with placebo (mean (SE) 37.6 (1.12) 1/min compared with 28.0 (1.13) 1/min, p < 0.006). The PD20VE increased 19% (95% CI 8 to 31) after treatment with BAYx 1005 compared with placebo (57.3(1.10)1/min versus 48.1 (1.10) 1/min, p < 0.002). Treatment with BAYx 1005 produced a 15.4% decrease in ionophore-stimulated LTB4 production, while treatment with placebo produced a 7.1% increase in ex vivo LTB4 (p < 0.02).. Treatment with BAYx 1005, a novel inhibitor of leukotriene synthesis, produced a significant blunting of cold dry air responsiveness consistent with the hypothesis that leukotrienes mediate part of the bronchoconstriction induced by hyperventilation of cold dry air.

Topics: Adolescent; Adult; Analysis of Variance; Asthma; Bronchial Provocation Tests; Calcimycin; Cold Temperature; Cross-Over Studies; Double-Blind Method; Humans; Ionophores; Leukotriene B4; Lipoxygenase Inhibitors; Middle Aged; Quinolines

Recent information suggests that one of the therapeutic properties of theophylline is an antiinflammatory effect.. We evaluated this potential effect of theophylline in eight patients with nocturnal asthma.. The study design was a randomized, double-blind, placebo-controlled crossover of 2-week treatment periods, separated by a 1-week washout period. Spirometry and bronchoscopy were performed.. Theophylline, compared with placebo, significantly improved the overnight decrement in lung function. The higher the nocturnal theophylline level, the greater the improvement in lung function. Theophylline also significantly decreased the percentage of neutrophils in the 4:00 AM bronchoalveolar lavage fluid and stimulated leukotriene B4 levels from macrophages obtained at 4:00 AM. The greater change in neutrophils correlated with increasing serum theophylline concentration. Also, the change in leukotriene B4 production was significantly correlated with the theophylline-induced decrement in lavage granulocytes (neutrophils and eosinophils).. This study suggests that one action of theophylline is to alter inflammatory cell number and function in nocturnal asthma and that it may do this through an leukotriene B4-mediated mechanism.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Asthma; Bronchoalveolar Lavage Fluid; Circadian Rhythm; Cross-Over Studies; Female; Humans; Leukocyte Count; Leukotriene B4; Lung; Male; Theophylline

Leukotriene (LT) B4 is a potent neutrophil chemoattractant and also stimulates eosinophils in vitro, but its role in asthmatic inflammation is unknown.. The effect of the novel LTB4 receptor antagonist, LY293111, was examined using allergen challenge as a model for asthmatic inflammation in 12 atopic asthmatic subjects in a double blind placebo controlled crossover trial. Subjects with an established early (EAR) and late asthmatic response (LAR) to allergen at screening received oral LY293111 in a dose of 112 mg three times daily for seven days or placebo before further allergen challenge. Each treatment was separated by a washout period of 28 days. Individuals underwent histamine challenge one hour before and three hours after allergen challenge. Bronchoalveolar lavage (BAL) fluid was obtained at bronchoscopy 24 hours after allergen challenge.. There was no difference in baseline lung function, EAR, LAR, or in airway responsiveness to histamine before and after allergen between placebo and LY293111. By contrast, treatment with LY293111 significantly reduced the number of neutrophils in BAL fluid expressed as both absolute cell numbers and percentage cell differential counts: absolute cell counts, median (range) 0.04 (0.02-0.15) x 10(6) after LY293111, 0.09 (0.02-0.43) x 10(6) after placebo; percentage differential cell counts 0.35 (0.1-2.0) after LY293111, 0.80 (0.1-3.6) after placebo (p < 0.05). Eosinophils, macrophages, and lymphocytes in BAL fluid did not differ between treatments. There was a significant reduction in the concentration of myeloperoxidase (MPO) with both placebo (16 (6.6) ng/ml) and LY293111 (3.5 (1.8) ng/ml) and of LTB4 (placebo 4.6 (1.2) pg/ml, LY293111 2.2 (0.2) pg/ml). Concentrations of LTC4 and interleukin 8 were reduced, although not significantly, whereas concentrations of interleukin 6, GM-CSF, and TNF-alpha were unchanged by LY293111.. These results demonstrate an influence of LTB4 on neutrophil influx and activation in the airway following allergen challenge. Despite this anti-inflammatory effect, there was no measured physiological benefit and this questions the functional role of the neutrophil in the pathophysiology of allergen induced asthma.

Topics: Adult; Allergens; Asthma; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Cross-Over Studies; Cytokines; Double-Blind Method; Forced Expiratory Volume; Histamine; Humans; Leukotriene B4; Male; Peroxidase; Prostaglandins; Receptors, Leukotriene B4; Thromboxanes

Nocturnal worsening of asthma is associated with an increase in numbers of airway inflammatory cells during the early morning. However, cell function during the night, with and without administration of steroids, has not been investigated.. This study was designed to determine the effect of prednisone on pulmonary alveolar macrophage production of leukotriene B2 and thromboxane B2 at night and how it relates to changes in pulmonary function and cellular influx.. Alveolar macrophages were obtained from patients with nocturnal asthma, patients with nonnocturnal asthma, and normal control subjects at 4:00 AM by bronchoalveolar lavage after administration of placebo and prednisone. Cells were placed in limited cell culture, and eicosanoids were measured from baseline and stimulated cells.. Patients with nocturnal asthma had both a significantly greater fall in forced expiratory volume in 1 second (FEV1) and a greater influx of neutrophils and eosinophils at 4:00 AM than normal subjects after placebo treatment, whereas patients with nonnocturnal asthma had intermediary responses. There was no difference in baseline or stimulated LTB4 production during placebo administration in the three groups. After prednisone treatment, there was an improvement in the nocturnal fall in FEV1 and a significant decrease in the neutrophil influx in patients with nocturnal asthma compared with the other groups. These changes were accompanied by a significant decrease in the stimulated LTB4 production in patients with nocturnal asthma compared with a small increase in both patients with nonnocturnal asthma and normal subjects. Thromboxane B2 production did not change. The decrease in LTB4 production was correlated with the fall in granulocytic cells and improvement in the nocturnal FEV1. However, the two variables with the greatest combined influence on the improvement in FEV1 were the decrease in stimulated LTB4 production and the fall in neutrophil influx.. We demonstrate for the first time that a single oral dose of prednisone decreases LTB4 production from alveolar macrophages, obtained at night from patients with nocturnal asthma, during a time of known inflammation. Further, this decrease in stimulated production is associated with decreases in cellular influx and improvement in pulmonary function.

Topics: Administration, Oral; Adolescent; Adult; Asthma; Bronchoalveolar Lavage Fluid; Cell Count; Circadian Rhythm; Cross-Over Studies; Eicosanoids; Female; Forced Expiratory Volume; Humans; Leukocytes; Leukotriene B4; Macrophages, Alveolar; Male; Middle Aged; Placebos; Prednisone; Reference Values; Respiratory Function Tests

Leukotrienes are lipid mediators generated from arachidonic acid by the 5-lipoxygenase pathway which may play an important part in the pathophysiology of asthma. Previous studies have demonstrated attenuation of the allergen-induced early and late asthmatic responses by leukotriene receptor antagonists. The effect of the 5-lipoxygenase inhibitor ZD2138, a non-redox lipoxygenase inhibitor which inhibits leukotriene synthesis for 24 hours after single doses of 350 mg, on allergen-induced early and late asthmatic responses has been assessed.. Eight asthmatic subjects with baseline FEV1 > 70% were studied. On screening, all subjects developed an allergen-induced biphasic asthmatic response to grass pollen, cat dander, or house dust mite. ZD2138 (350 mg) or placebo was given on two occasions separated by two weeks in a randomised double blind fashion. Allergen inhalation challenge was performed four hours after dosing and FEV1 was measured for eight hours. The inhibitory activity of ZD2138 on the 5-lipoxygenase pathway was assessed by measurements of calcium ionophore-stimulated generation of LTB4 in whole blood ex vivo and by analysis of urinary LTE4 levels before administration of drug or placebo and at regular intervals after oral drug dosing and allergen challenge.. ZD2138 produced no significant bronchodilatation or attenuation of the early or late asthmatic response, although there was 82% inhibition of whole blood generation of LTB4 in response to calcium ionophore stimulation and 52% reduction in urinary excretion of LTE4.. In asthmatic subjects the 5-lipoxygenase inhibitor ZD2138 did not protect against allergen-induced asthmatic responses, despite substantial inhibition of 5-lipoxygenase.

Topics: Adult; Asthma; Bronchial Provocation Tests; Double-Blind Method; Forced Expiratory Volume; Humans; Hypersensitivity, Delayed; Hypersensitivity, Immediate; In Vitro Techniques; Leukotriene B4; Leukotriene E4; Lipoxygenase Inhibitors; Male; Pyrans; Quinolones; Spirometry

Although the mechanism of aspirin-induced asthma and rhinitis is unknown, it has been suggested that adverse nasal and bronchial reactions are caused by an increased production of lipoxygenase products. In examining this hypothesis we have measured the release of peptide leukotrienes (PeptLTs), 15-HETE, and prostaglandins in nasal fluids obtained by nasal lavages after instillation of acetylsalycilic acid (ASA) and placebo (saline). Ten ASA-sensitive asthmatics, 10 ASA-insensitive asthmatics, and seven healthy subjects were challenged in a double-blind study with normal saline and 12 mg of ASA. Twelve mg were administered based on the results of a previous study that showed that this dose caused minor to moderate symptoms in ASA-sensitive patients. PeptLTs, LTB4, 15-HETE, PGE2, PGF2 alpha, and PGD2 were measured by radioimmunoassay methods. Significant levels of PeptLTs were detected in sensitive asthmatic patients 60 min after nasal challenge. This change was associated with a significant increase in symptoms. No increase in PeptLTs levels were found, however, in either insensitive patients or healthy subjects. Inhibition of PGE2 and PGF2 alpha release was detected in the three groups after ASA administration. ASA also inhibited PGD2 release in insensitive asthmatic patients but not in both sensitive patients and healthy subjects. These results suggest that an abnormal release of PeptLTs in ASA-sensitive asthmatic patients contributes to nasal and bronchial adverse reactions. The lack of effects on PGD2 release suggests that mast cells from ASA-insensitive patients are more sensitive to ASA than those from sensitive asthmatic patients and healthy subjects.

Topics: Administration, Intranasal; Adult; Albumins; Aspirin; Asthma; Dinoprost; Dinoprostone; Drug Hypersensitivity; Female; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Leukotrienes; Male; Middle Aged; Nasal Mucosa; Prostaglandin D2

The effect of a single oral dose (800 mg) of zileuton (A-64077), a specific 5-lipoxygenase inhibitor, on the early and late airway responses to inhaled allergen was studied in a randomised, double blind, placebo controlled, and crossover trial in nine subjects with atopic asthma. Leukotriene generation was also assessed in vivo by measuring urinary leukotriene (LT) E4 excretion, and ex vivo by measuring calcium ionophore stimulated whole blood LTB4 production. Zileuton almost completely inhibited ex vivo LTB4 production but reduced urinary excretion of LTE4 by only about half. There was a trend for the early asthmatic response to be less on the day of zileuton treatment, but this did not reach statistical significance (p = 0.08). The zileuton induced reduction in maximum fall in FEV1 in the early asthmatic response was, however, significantly related to the reduction in urinary LTE4 excretion (r = 0.8), but not to the reduction in LTB4 generation ex vivo. There was no significant change in the allergen induced late asthmatic response, or in the increase in airway responsiveness to methacholine following antigen. The results provide some support for the hypothesis that the cysteinyl leukotrienes have a role in the allergen induced early asthmatic response. More complete in vivo inhibition of 5-lipoxygenase may be needed to produce a significant reduction in airway response to allergen challenge.

Topics: Adult; Allergens; Asthma; Double-Blind Method; Forced Expiratory Volume; Humans; Hydroxyurea; Leukotriene B4; Leukotriene E4; Lipoxygenase Inhibitors; Male; SRS-A; Time Factors

The effects of dietary supplementation with fish oil lipids on the airways responses to allergen and neutrophil biochemistry and function have been studied in 17 atopic asthmatic subjects. Nine subjects received 18 capsules of Max-EPA (3.2 g eicosapentaenoic acid and 2.2 g docosahexaenoic acid) a day and eight subjects received identical capsules containing olive oil, for 10 wk in a double-blind fashion. There were no differences between prediet values and those observed after dietary supplementation with Max-EPA or placebo in the dose of allergen causing an acute asthmatic response as assessed by a 35% fall in specific airways conductance (PD35), the extinction dose of allergen on skin prick testing, the histamine PD35, or the total serum IgE concentrations. Twelve of the 17 subjects developed late asthmatic responses after allergen challenge prediet. Six of these subjects received Max-EPA, and six received placebo capsules. As compared to prediet values, the magnitude of the allergen-induced late asthmatic response was significantly attenuated from 2 to 7 h after allergen challenge following dietary supplementation with Max-EPA (p less than 0.005) but not with placebo. The attenuation of the late response was not accompanied by any significant change in the clinical severity of disease as assessed by diurnal peak expiratory flow rates, symptom scores, or bronchodilator drug usage.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; Airway Resistance; Allergens; Asthma; Bronchi; Bronchial Provocation Tests; Chemotaxis, Leukocyte; Docosahexaenoic Acids; Double-Blind Method; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids; Fatty Acids, Unsaturated; Female; Fish Oils; Histamine; Humans; Immunoglobulin E; Leukotriene B4; Male; Neutrophils; Skin Tests; Time Factors

Leukotriene B4 (LTB4) is a potent chemoattractant that can recruit and activate immune cells such as neutrophils, eosinophils, and monocytes to sites of inflammation. Excessive production of LTB4 has been linked to acute and chronic inflammatory diseases, including asthma, rheumatoid arthritis, and psoriasis. Inhibiting the binding of LTB4 to its receptors, BLT1 and BLT2, is a potential strategy for treating these conditions. While several BLT1 antagonists have been developed for clinical trials, most have failed due to efficacy and safety issues. Therefore, discovering selective BLT2 antagonists could improve our understanding of the distinct functions of BLT1 and BLT2 receptors and their pharmacological implications. In this study, we aimed to discover novel BLT2 antagonists by synthesizing a series of biphenyl analogues based on a BLT2 selective agonist, CAY10583. Among the synthesized compounds, 15b was found to selectively inhibit the chemotaxis of CHO-BLT2 cells with an IC

Topics: Animals; Arthritis, Rheumatoid; Asthma; CHO Cells; Cricetinae; Inflammation; Leukotriene B4; Mice; Receptors, Leukotriene B4

Ganoderma, a fungal genus, is a traditional medicine with immuno-modulating effects. Asthma is an inflammatory disease of airways, and the main trigger of asthma is allergic inflammation. In this study, the effects of Ganoderma (an anti-inflammatory agent) given via oral administration (G/O) or intraperitoneal injection (G/IP) on asthma was evaluated. Forty BALB/c mice were divided into four groups, including the control, OVA-challenge, OVA-challenge + G/O, and OVA-challenge + G/IP. To determine AHR, the MCh challenge test was done. The levels of IL-1β, -4, -5, -6, -8, -10, -12, -13, -17, -25, -33, -38, Cys-LT, LTB4, and hydroxyproline were measured. Finally, lung histopathology was evaluated to determine eosinophilic inflammation, goblet cell hyperplasia, and mucus hyper-secretion. Treatment with G/O and G/IP could significantly reduce the levels of IL-1β, -5, -6, -8, -17, -25, -33, and -38; the levels of IL-4 and IL-13 had no significant changes, but the levels of IL-10 and IL-12 were enhanced. The mice treated with G/O and G/IP showed decreased levels of Cys-LT, LTB4, peribronchial and perivascular inflammation, but no significant changes were observed in AHR, hydroxyproline level, goblet cell hyperplasia, and mucus hyper-secretion. Ganoderma can be applied as an immunomodulatory and anti-inflammatory agent for managing asthma.

Topics: Animals; Anti-Inflammatory Agents; Asthma; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Ganoderma; Hydroxyproline; Hyperplasia; Inflammation; Leukotriene B4; Lung; Mice; Mice, Inbred BALB C; Ovalbumin

Topics: Animals; Anti-Allergic Agents; Asthma; Cytokines; Disease Models, Animal; Immunoglobulin E; Inflammation; Leukotriene B4; Leukotriene C4; Lung; Mice; Mice, Inbred BALB C; Mucoproteins; Respiratory Hypersensitivity

To study the effect of Hanchuan Zupa granule combined with conventional western medicine in the treatment of children with bronchial asthma.. 98 cases in Fengrun District People's Hospital of Tangshan City from June 2018 to February 2021 were selected. The control group was given oxygen therapy, antibiotics, and aerosol inhalation of quick acting. After treatment, the levels of sputum IL-4, IL-17, neu, and ECP in the two groups decreased, and the observation group was lower than the control group (. Bairui granule combined with conventional western medicine in the treatment of children with bronchial asthma, the curative effect is worthy of affirmation, can effectively improve cough symptoms, reduce EOS, CXCR, LTB4, SDF-1 levels, inhibit airway inflammation, and has good clinical application value.

Topics: Asthma; Child; Cough; Eosinophils; Humans; Inflammation Mediators; Leukotriene B4; Leukotriene C4; Sputum

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

We investigated the effects of resolvin E (RvE) 1, RvE2, and RvE3 on IL-4- and IL-33-stimulated bone marrow-derived dendritic cells (BMDCs) from house dust mite (HDM)-sensitized mice. We also investigated the role of RvE3 in a murine model of HDM-induced airway inflammation.

Topics: Animals; Asthma; beta-Arrestin 2; Bone Marrow Cells; Dendritic Cells; Fatty Acids, Unsaturated; Female; Gene Expression Regulation; Interleukin-17; Interleukin-23 Subunit p19; Leukotriene B4; Mice; Mice, Inbred BALB C; Pyroglyphidae; Receptors, Leukotriene B4; Signal Transduction

Asthma is associated with the overproduction of leukotrienes (LTs), including LTB4. Patients with severe asthma can be highly responsive to 5-lipoxygenase (5-LO) inhibition, which blocks production of both the cysteinyl LTs and LTB4. Production of LTB4 has traditionally been ascribed to neutrophils, mononuclear phagocytes, and epithelial cells, and acts as a chemoattractant for inflammatory cells associated with asthma. The source of LTB4 is unclear, especially in eosinophilic asthma. We speculated that the benefit of 5-LO inhibition could be mediated in part by inhibition of eosinophil-derived LTB4. LTB4 concentrations were assayed in BAL fluid from patients with severe asthma characterized by isolated neutrophilic, eosinophilic, and paucigranulocytic inflammation. Expression of LTA4 hydrolase (LTA4H) by airway eosinophils was determined by immunohistochemistry (IHC). Subsequently, peripheral blood eosinophils were activated and secreted LTB4 was quantified by enzyme immunoassay. Blood eosinophil LTA4H expression was determined by flow cytometry, qPCR, and IHC. LTB4 concentrations were elevated in BAL fluid from patients with severe asthma, including those with isolated eosinophilic inflammation, and these eosinophils displayed LTA4H via IHC. LTA4H expression by blood eosinophils was confirmed by flow cytometry, IHC, and qPCR. Robust LTB4 production by blood eosinophils was observed in response to some, but not all, stimuli. We demonstrated that eosinophils express LTA4H transcripts and protein, and can be stimulated to secrete LTB4. We speculate that in many patients with asthma, eosinophil-derived LTB4 is increased, and this may contribute to the efficacy of 5-LO inhibition.

Topics: Arachidonate 5-Lipoxygenase; Asthma; Bronchoalveolar Lavage Fluid; Child; Child, Preschool; Eosinophils; Epoxide Hydrolases; Female; Humans; Leukotriene B4; Lipoxygenase Inhibitors; Male; Neutrophils

Topics: Asthma; Eosinophils; Epoxide Hydrolases; Humans; Leukotriene B4

Various inflammatory eicosanoid levels in biomaterials from airways of asthma and their associations with clinical parameters remain uncertain. We hypothesized that prostaglandin and leukotriene levels differ between in exhaled breath condensates (EBCs) and in sputum in mild, moderate, and severe levels of asthma and that EBC and sputum eicosanoid levels are associated with indexes of pulmonary function and inflammation.. To determine the differences between EBC and sputum eicosanoid levels in healthy participants and patients with asthma with different asthma severity levels.. Collected EBC and sputum, as well as pulmonary function, were examined in adult patients with asthma and healthy participants. Exhaled breath condensate prostaglandin D2-methoxime (PGD2-MOX), cysteinyl leukotrienes (CysLTs), leukotriene B4 (LTB4), and thromboxane B2 levels, and some sputum eicosanoid and tryptase levels were measured. Differences in eicosanoid levels among participants and their associations with pulmonary function and tryptase and granulocyte levels in sputum were then evaluated.. Analysis of 94 EBCs and 43 sputa revealed that EBC and sputum PGD2-MOX and CysLT levels were significantly higher in patients with asthma than in healthy participants. Exhaled breath condensate PGD2-MOX, CysLT, and LTB4 levels were significantly higher in patients with severe asthma. Exhaled breath condensate PGD2-MOX level was also significantly correlated with sputum tryptase levels and lower pulmonary function in patients with asthma. Sputum PGD2-MOX and CysLT levels were significantly correlated with the proportion of eosinophils among all cells in sputum in patients with asthma.. The results suggest that EBC PGD2 levels are associated with impairment of pulmonary function in adults with asthma who have undergone guideline treatment. Exhaled breath condensate or sputum PGD2 and CysLTs may represent severity or airway inflammation in asthma.

Topics: Adult; Asthma; Breath Tests; Cysteine; Eicosanoids; Female; Granulocytes; Humans; Inflammation; Leukotriene B4; Leukotrienes; Lung; Male; Middle Aged; Prostaglandin D2; Sputum; Thromboxane B2; Tryptases

Aberrant generation of eicosanoids is associated with asthma, but the evidence remains incomplete and its potential utility as biomarkers is unclear. Major eicosanoids in exhaled breath condensates (EBCs) were assessed as candidate markers for childhood asthma.. Ten exhaled eicosanoid species was evaluated using ELISA in the discovery phase, followed by prediction model-building and validation phases.. Exhaled LTB. In a pediatric study population in Taiwan, the levels of exhaled LTB

Topics: Algorithms; Area Under Curve; Asthma; Biomarkers; Breath Tests; Child; Child, Preschool; Dinoprostone; Eicosanoids; Female; Forced Expiratory Volume; Humans; Leukotriene B4; Leukotriene E4; Lipoxins; Male; Nitric Oxide; ROC Curve; Sensitivity and Specificity

Calcium-binding protein spermatid-specific 1 (CABS1) is expressed in the human submandibular gland and has an anti-inflammatory motif similar to that in submandibular rat 1 in rats. Here, we investigate CABS1 in human saliva and its association with psychological and physiological distress and inflammation in humans. Volunteers participated across three studies:

Topics: Adolescent; Adult; Affect; Asthma; Biomarkers; Calcium-Binding Proteins; Female; Forced Expiratory Volume; Heart Rate; Humans; Hydrocortisone; Leukotriene B4; Male; Mathematical Concepts; Middle Aged; Molecular Weight; Respiratory Rate; Saliva; Speech; Stress, Psychological; Time Factors; Up-Regulation; Vascular Endothelial Growth Factor A; Young Adult

Topics: 5-Lipoxygenase-Activating Proteins; Acetates; Animals; Asthma; Cell Movement; Chemokines; Cyclopropanes; Epoxide Hydrolases; Humans; Inflammation; Leukotriene B4; Lipid Metabolism; Molecular Targeted Therapy; Neutrophil Activation; Neutrophils; Quinolines; Sulfides; T-Lymphocytes

Lipoxins are biologically active eicosanoids with anti-inflammatory properties. Lipoxin A4 (LXA4) signaling blocks asthmatic responses in human and experimental model systems. There is evidence that patients with respiratory diseases, including severe asthma (SA), display defective generation of lipoxin signals despite glucocorticoid therapy.. We investigated airway levels of formyl peptide receptor 2-lipoxin receptor (FPR2/ALXR), LXA4, and its counterregulatory compound, leukotriene B4 (LTB4), in patients with childhood asthma. We addressed the potential interplay of the LXA4-FPR2/ALXR axis and glucocorticoids in the resolution of inflammation.. We examined LXA4 and LTB4 concentrations in induced sputum supernatants from children with intermittent asthma (IA), children with SA, and healthy control (HC) children. In addition, we investigated FPR2/ALXR expression in induced sputum cells obtained from the study groups. Finally, we evaluated in vitro the molecular interaction between LXA4 and glucocorticoid receptor-based mechanisms.. We found that children with SA have decreased LXA4 concentrations in induced sputum supernatants in comparison with children with IA. In contrast to decreases in LXA4 concentrations, LTB4 concentrations were increased in children with asthma independent of severity. LXA4 concentrations negatively correlated with LTB4 concentrations and with exacerbation numbers in children with SA. FPR2/ALXR expression was reduced in induced sputum cells of children with SA compared with that seen in HC subjects and children with IA. Finally, we describe in vitro the existence of crosstalk between LXA4 and glucocorticoid receptor at the cytosolic level mediated by G protein-coupled FPR2/ALXR in peripheral blood granulocytes isolated from HC subjects, children with IA, and children with SA.. Our findings provide evidence for defective LXA4 generation and FPR2/ALXR expression that, associated with increased LTB4, might be involved in a reduction in the ability of inhaled corticosteroids to impair control of airway inflammation in children with SA.

Topics: Adrenal Cortex Hormones; Asthma; Biomarkers; Case-Control Studies; Child; Child, Preschool; Female; Humans; Immunoglobulin E; Leukocytes; Leukotriene B4; Lipoxins; Male; Phosphorylation; Receptors, Formyl Peptide; Receptors, Glucocorticoid; Receptors, Lipoxin; Respiratory Function Tests; Severity of Illness Index; Signal Transduction; Skin Tests; Sputum

Topics: Adrenal Cortex Hormones; Asthma; Humans; Leukotriene B4; Lipoxins; Respiratory System

To examine the effect of final exam stress on the concentrations of leukotriene B4 (LTB4) and vascular endothelial growth factor (VEGF) in the upper airways among healthy and asthmatic individuals.. Nasal samples were collected from 12 individuals with asthma and 23 healthy controls early and late in a final exam period, and during a low-stress period in the semester. We determined LTB4 and VEGF concentrations using Enzyme-Linked Immunoassays.. Mixed effects analysis of variance models showed that asthmatic participants with allergies in contrast to healthy individuals experienced a decrease in nasal LTB4 during the final exam period as compared to mid-semester (low stress period). There were no significant changes in nasal VEGF across the observation period. Changes in nasal LTB4 and VEGF were not associated with salivary cortisol, exhaled nitric oxide, or spirometric lung function.. Our results suggest that nasal LTB4 concentrations change in periods of psychological stress for asthmatic individuals with allergies.

Topics: Adult; Asthma; Biomarkers; Case-Control Studies; Female; Humans; Leukotriene B4; Longitudinal Studies; Male; Nasal Mucosa; Stress, Psychological; Vascular Endothelial Growth Factor A; Young Adult

We examined composition of plasma non-esterified fatty acids (NFAs), erythrocyte fatty acids, levels of eicosanoids in patients with asthma and chronic obstructive pulmonary disease (COPD) with different type of the inflammatory response. The results of our study show that asthma and COPD in remission are associated with changes in the composition NFAs of plasma, FA of erythrocytes, level eicosanoid despite the difference in the regulation of immunological mechanisms of systemic inflammation. These changes are characterized by excessive production of arachidonic acid (20:4n-6) and cyclooxygenase and lipoxygenase metabolites (thromboxane B2, leukotriene B4) and deficiency of their functional antagonist, eicosapentaenoic acid (20:5n-3). The recognized association between altered fatty acid composition and disorders of the immune mechanisms of regulation of systemic inflammation in COPD and asthma demonstrated the important role of fatty acids and their metabolites in persistence of inflammatory processes in diseases of the respiratory system in the condition of remission.. Izuchen sostav zhirnykh kislot (ZhK) plazmy krovi i membran éritrotsitov, uroven' éĭkozanoidov u bol'nykh bronkhial'noĭ astmoĭ (BA) i khronicheskoĭ obstruktivnoĭ bolezn'iu legkikh (KhOBL) pri raznom tipe vospalitel'noĭ reaktsii. Ustanovleno, chto techenie BA i KhOBL v period remissii, nesmotria na razlichie immunologicheskikh mekhanizmov reguliatsii sistemnogo vospaleniia, soprovozhdaetsia odnonapravlennymi izmeneniiami sostava neéterifitsirovannykh zhirnykh kislot plazmy krovi i ZhK membran éritrotsitov, urovnia éĭkozanoidov, kharakterizuiushchimisia povyshennoĭ produktsieĭ arakhidonovoĭ kisloty (20:4n-6) i ee tsiklooksigenaznykh i lipoksigenaznykh metabolitov (tromboksan V2, leĭkotrien V4) na fone defitsita funktsional'nogo antagonista – éĭkozapentaenovoĭ kisloty (20:5n-3). Obnaruzhennaia assotsiatsiia mezhdu modifikatsieĭ sostava zhirnykh kislot krovi i narusheniem immunnykh mekhanizmov reguliatsii sistemnogo vospaleniia pri KhOBL i BA svidetel'stvuet o vazhnom znachenii zhirnykh kislot i ikh metabolitov v persistentsii vospalitel'nogo protsessa pri zabolevaniiakh bronkholegochnoĭ sistemy v period remissii.

Topics: Adult; Arachidonic Acid; Asthma; Case-Control Studies; Eicosapentaenoic Acid; Female; Humans; Inflammation; Leukotriene B4; Lipoxygenases; Male; Prostaglandin-Endoperoxide Synthases; Pulmonary Disease, Chronic Obstructive; Thromboxane B2

Asthma is a common chronic disease characterized by bronchial inflammation, reversible airway obstruction, and airway hyperresponsiveness (AHR). Current therapeutic options for the management of asthma include inhaled corticosteroids and β2 agonists, which elicit harmful side effects. In the present study, we examined the capacity of phospholipase A2 (PLA2), one of the major components of bee venom (BV), to reduce airway inflammation and improve lung function in an experimental model of asthma. Allergic asthma was induced in female BALB/c mice by intraperitoneal administration of ovalbumin (OVA) on days 0 and 14, followed by intratracheal challenge with 1% OVA six times between days 22 and 30. The infiltration of immune cells, such as Th2 cytokines in the lungs, and the lung histology, were assessed in the OVA-challenged mice in the presence and absence of an intratracheal administration of bvPLA2. We showed that the intratracheal administration of bvPLA2 markedly suppressed the OVA-induced allergic airway inflammation by reducing AHR, overall area of inflammation, and goblet cell hyperplasia. Furthermore, the suppression was associated with a significant decrease in the production of Th2 cytokines, such as IL-4, IL-5, and IL-13, and a reduction in the number of total cells, including eosinophils, macrophages, and neutrophils in the airway.

Topics: Allergens; Animals; Anti-Asthmatic Agents; Asthma; Bee Venoms; Bronchoalveolar Lavage Fluid; Cell Count; Cytokines; Female; Immunoglobulin E; Leukotriene B4; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Phospholipases A2

Sputum eosinophils and exhaled fractional nitric oxide (FENO) are markers of airway inflammation in asthma. Cytokines, cysteinyl-leukotrienes and leukotriene B4 (LTB4) are responsible for this inflammation. The aim of this study is to determine the usefulness of these markers in monitoring asthma treatment in children. FENO, sputum eosinophils, and LTB4 in induced sputum were performed in 10 children (9-15 years old). These determinations were repeated four months later, after the beginning or an increase in the treatment. FENO values tended to decrease (P=.15), pulmonary function tended to improve (P=.10), and sputum eosinophils decreased (P=.003) compared to the first determination. There were no differences in LTB4 concentrations (P=.88). Sputum eosinophils seem to be more precise than FENO in the monitoring of inflammation in asthmatic children.

Topics: Adolescent; Asthma; Breath Tests; Child; Eosinophils; Humans; Leukocyte Count; Leukotriene B4; Monitoring, Physiologic; Nitric Oxide; Prospective Studies; Sputum

Inflammatory processes in the asthmatic lung involve the large and small airway and alveolar sites. Leukotriene B4 (LTB₄) is an important disease marker, but its role in inflammation of the small airways in asthma has not been established yet.. To distinguish between large and small airway or alveolar LTB₄ concentrations in children with asthma using the new technique of fractionated exhaled breath condensate sampling.. Sixty-eight children (9-17 years old, 33 children with asthma and 35 controls) underwent fractional exhaled nitric oxide (FeNO) measurements, lung function testing, and collection of fractionated exhaled breath condensate using a capnograph-based approach. The LTB₄ concentrations in the small airway or alveolar and large airway fractions were correlated to disease status, lung function impairment, and clinical parameters.. Children with asthma had significantly higher LTB₄ concentrations in the small airway or alveolar fraction than controls (5.58 pg/mL; 95% interquartile range [IQR], 2.0-11.77 pg/mL; vs 2.0 pg/mL; 95% IQR, 2.0-6.2 pg/mL; P = .003). No difference was found between the groups in the large airway fraction. Children with obstructive lung function impairment (forced expiratory volume in 1 second z score <-1.65) had increased small airway or alveolar LTB₄ concentrations compared with children without impairment (2.0 pg/mL; 95% IQR, 2.0-9.21 pg/mL; vs 18.32 pg/mL; 95% IQR, 3.7-23.02 pg/mL; P = .04). Children with asthma but without pathologic obstructive lung function still had higher LTB₄ concentrations than controls (5.57 pg/mL; 95% IQR, 2.00-10.60 pg/mL; vs 2.00 pg/mL; 95% IQR, 2.00-6.20 pg/mL; P = .01).. LTB₄ is detectable and elevated in the small airway or alveolar fraction of exhaled breath condensate in pediatric asthma. Because of the possibility of detecting elevated levels in patients without lung function impairment in controlled disease, it may be used as a noninvasive marker of small airways disease; however, future long-term studies are needed.

Topics: Adolescent; Asthma; Breath Tests; Child; Exhalation; Female; Forced Expiratory Volume; Humans; Inflammation; Leukotriene B4; Male; Nitric Oxide

In addition to lung volume restriction, individuals with chronic tetraplegia exhibit reduced airway caliber and bronchodilator responsiveness similar to persons with asthma. In asthma, airflow obstruction is closely linked to airway inflammation. Conversely, little is known regarding the airway inflammatory response in tetraplegia. To compare levels of biomarkers of inflammation in exhaled breath condensate (EBC) and serum in subjects with chronic tetraplegia, mild asthma, and able-bodied controls.Prospective, observational pilot study. Thirty-four subjects participated: tetraplegia (n = 12), asthma (n = 12), controls (n = 10). Biomarkers in EBC [8-isoprostane (8-IP), leukotriene B4 (LT-B4), prostaglandin E2 (PG-E2), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6)] and serum (8-IP, LT-B4, TNF-α, IL-6) were determined using commercially available EIA kits (Cayman Chemical Company, Ann Arbor, MI). Separate, one-way ANOVA with Bonferroni's post-hoc analyses were performed to determine group differences in demographic and dependent variables [EBC and serum biomarkers, fractional exhaled nitric oxide (FeNO), pulmonary function parameters, and specific airway conductance (sGaw)]. The tetraplegia group had significantly elevated 8-IP levels in EBC compared to the asthma (68 ± 38 versus 21 ± 13 pg ml(-1); p < 0.001) and control groups (22 ± 13 pg ml(-1); p < 0.01), respectively. FeNO levels were significantly elevated in the asthma compared to the control group (26 ± 18 versus 11 ± 4 ppb; p < 0.05), and trended higher than levels in the tetraplegia group (15 ± 6; p = 0.08). Levels of serum biomarkers did not differ significantly among groups. Through analysis of EBC, levels of 8-IP were significantly elevated compared to levels found in individuals with mild asthma and healthy controls. Further studies are needed to extend upon these preliminary findings that suggest the presence of airway inflammation in subjects with chronic tetraplegia, and how this relates to pulmonary dysfunction in this population.

Topics: Asthma; Biomarkers; Breath Tests; Case-Control Studies; Dinoprost; Exhalation; Female; Humans; Inflammation; Interleukin-6; Leukotriene B4; Male; Middle Aged; Nitric Oxide; Pilot Projects; Prospective Studies; Quadriplegia; Tumor Necrosis Factor-alpha

The 5-lipoxygenase product 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is the most powerful human eosinophil chemoattractant among lipid mediators and could play a major pathophysiological role in eosinophilic diseases such as asthma. Its actions are mediated by the OXE receptor, orthologs of which are found in many species from humans to fish, but not rodents. The unavailability of rodent models to examine the pathophysiological roles of 5-oxo-ETE and the OXE receptor has substantially hampered progress in this area. As an alternative, we have explored the possibility that the cat could serve as an appropriate animal model to investigate the role of 5-oxo-ETE. We found that feline peripheral blood leukocytes synthesize 5-oxo-ETE and that physiologically relevant levels of 5-oxo-ETE are present in bronchoalveolar lavage fluid from cats with experimentally induced asthma. 5-Oxo-ETE (EC50, 0.7nM) is a much more potent activator of actin polymerization in feline eosinophils than various other eicosanoids, including leukotriene (LT) B4 and prostaglandin D2. 5-Oxo-ETE and LTB4 induce feline leukocyte migration to similar extents at low concentrations (1nM), but at higher concentrations the response to 5-oxo-ETE is much greater. Although high concentrations of selective human OXE receptor antagonists blocked 5-oxo-ETE-induced actin polymerization in feline granulocytes, their potencies were about 200 times lower than for human granulocytes. We conclude that feline leukocytes synthesize and respond to 5-oxo-ETE, which could potentially play an important role in feline asthma, a common condition in this species. The cat could serve as a useful animal model to investigate the pathophysiological role of 5-oxo-ETE.

Topics: Actins; Allergens; Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acids; Asthma; Benzeneacetamides; Benzothiazoles; Bronchoalveolar Lavage Fluid; Cats; Chemotaxis; Cynodon; Disease Models, Animal; Eosinophils; Female; Gene Expression; Humans; Leukotriene B4; Male; Neutrophils; Polymerization; Primary Cell Culture; Prostaglandin D2; Receptors, Eicosanoid

Leukotriene B4 (LTB4) is a potent mediator of inflammation and plays a key function in the pathophysiology of chronic asthma. Detectable urinary levels of LTB4, arises from the activation of leukotriene pathways. In this study an ultra-fast, selective and sensitive analytical method based on semi-automatic microextraction by packed sorbents (MEPS) technique, using a new digitally controlled syringe (eVol®) combined with ultra-high pressure liquid chromatography (UHPLC), is proposed for the measurement of urinary LTB4 (U-LTB4) levels in a group of asthmatic patients (APs) and healthy controls (CTRL). Important parameters affecting MEPS performance, namely sorbent type, number of extraction cycles (extract-discard) and elution volume, were evaluated. The optimal experimental conditions among those investigated for the quantification of U-LTB4 in urine samples were as follows: porous graphitic carbon sorbent (PGC), 10 extractions cycle (10×250 μL of sample) and LTB4 elution with 100 μL of acetonitrile. The UHPLC optimum conditions resulted in a mobile phase consisting of 95% (v/v) of acid aqueous solution (v/v), and acetonitrile 5% (v/v); flow rate of 500 µL/min, and a column temperature of 37±0.1 °C. Under optimized conditions the proposed method exhibit good selectivity and sensitivity LOD (0.37 ng/mL) and LOQ (1.22 ng/mL). The recovery ranging from 86.4 to 101.1% for LTB4, with relative standard deviations (% RSD) no larger than 5%. In addition, the method also afforded good results in terms of linearity (r(2)>0.995) within the established concentration range, with a residual deviation for each calibration point below 6%, and intra- and inter-day repeatability in urine samples with RSD values lower than 4 and 5%, respectively. The application of the method to urine samples revealed a tendency towards the increased urinary LTB4 levels in APs (5.42±0.17 ng/mL) when compared to those of CTRL group (from ND to 1.9 ng/mL). Urinary measurement of LTB4 may be an interesting and non-invasive option to assess control of asthma.

Topics: Adolescent; Asthma; Automation; Chromatography, High Pressure Liquid; Cost-Benefit Analysis; Female; Humans; Leukotriene B4; Limit of Detection; Male; Semiconductors; Solid Phase Microextraction; Time Factors; Urinalysis

Topics: Asthma; Female; Humans; Leukotriene B4; Lipoxins; Male

Leukotriene B4 (LTB4), a potent lipid mediator of inflammation derived from arachidonic acid through the action of 5-lipoxygenase, has been implicated in the pathophysiology of several inflammatory diseases, including asthma and chronic obstructive pulmonary disease. A high-affinity LTB4 receptor BLT1 has been shown to exert proinflammatory roles. A cyclooxygenase metabolite, 12(S)-hydroxyheptadeca-5Z, 8E, 10E-trienoic acid (12-HHT), is an endogenous ligand for BLT2, a low-affinity LTB4 receptor. The recent study indicated that BLT2 has a protective role in allergic airway inflammation, suggesting different functions between BLT1 and BLT2 in the pathogenesis of asthma. Selective BLT1 antagonists may have a potential therapeutic application in patients with asthma, and BLT2 may represent a novel therapeutic target for lung diseases.

Topics: Asthma; Humans; Leukotriene B4; Lung; Receptors, Leukotriene B4; Signal Transduction

Leukotriene B4 (LTB4) has been implicated in the pathogenesis of allergic diseases. BLT2, a low-affinity LTB4 receptor, is activated by LTB4 and 12(S)-hydroxyheptadeca-5Z,8E,10E-trienoic acid (12-HHT). Although the high-affinity LTB4 receptor BLT1 has been shown to exert proinflammatory roles, the role of BLT2 in allergic inflammation has not been clarified. To study the function of BLT2 in development of asthma, we used mice model of ovalbumin (OVA)-induced allergic airway disease. The 12-HHT levels were elevated in bronchoalveolar lavage (BAL) fluids of OVA-sensitized/challenged wild-type mice. BLT2-deficient mice exhibited enhanced eosinophilia in BAL fluids after OVA exposure. Interleukin (IL)-13 levels in BAL fluids and IL-13-producing CD4(+) T cells in the lungs were elevated in BLT2-deficient mice compared to wild-type mice, whereas the levels of IL-4, IL-5, and interferon (IFN)-γ in BAL fluids and serum OVA-specific IgE were comparable. Transfection of BLT2-specific small interfering RNA enhanced IL-13 production in CD4(+) T cells in vitro. Expression of BLT2 mRNA in CD4(+) T cells was significantly reduced in patients with asthma compared to healthy control subjects. These findings indicate that BLT2 has a protective role in allergic airway inflammation and that diminished BLT2 expression in CD4(+) T cells may contribute to the pathophysiology of asthma.

Topics: Adult; Aged; Animals; Asthma; Bronchoalveolar Lavage Fluid; Calcium; CD4-Positive T-Lymphocytes; CHO Cells; Cricetinae; Cricetulus; Cytokines; Eosinophilia; Fatty Acids, Unsaturated; Humans; Leukotriene B4; Lung; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; Receptors, Leukotriene B4; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; Young Adult

The relationship between anti-inflammatory lipoxins and proinflammatory leukotrienes might be important in the pathobiology and severity of asthma.. We sought to investigate whether exhaled breath condensate (EBC) lipoxin and leukotriene measurements can noninvasively characterize the asthmatic diathesis and its severity.. We measured lipoxin A4 (LXA4) and leukotriene B4 (LTB4) levels in EBC collected from patients with asthma of different severities and from healthy control subjects.. EBC LXA4 and LTB4 levels are increased in asthmatic patients compared with those seen in healthy control subjects (LXA4: 31.40 vs 2.41 pg/mL EBC, respectively [P < .001]; LTB4: 45.62 vs 3.82 pg/mL EBC, respectively [P < .001]). Although levels of both eicosanoids are increased in asthmatic patients, the LXA4/LTB4 ratio decreases with increasing asthma severity. It is 41% lower in patients with severe versus moderate asthma (0.52 vs 0.88, P = .034). EBC LXA4 levels correlate with the degree of airflow obstruction measured by using FEV1 (r = 0.28, P = .018). An LXA4 cutoff value of 7 pg/mL EBC provides 90% sensitivity and 92% specificity for the diagnosis of asthma (area under the curve, 0.96; P < .001). An LTB4 cutoff value of 11 pg/mL EBC provides 100% sensitivity and 100% specificity for the diagnosis of asthma (area under the curve, 1; P < .001).. Proresolving and proinflammatory eicosanoids are generated in the airways of all asthmatic patients. The proportion of proresolving compounds decreases with asthma severity. These findings support the role for EBC eicosanoid measurements in the noninvasive diagnosis of asthma and suggest that proresolving eicosanoid pathways are dysregulated in patients with severe asthma.

Topics: Adolescent; Adult; Asthma; Breath Tests; Exhalation; Female; Humans; Leukotriene B4; Lipoxins; Male; Middle Aged; Severity of Illness Index; Young Adult

Non-invasive methods to assess inflammation of lower airways are induced sputum (IS), exhaled nitric oxide (eNO), and exhaled breath condensate (EBC). Here we focused on the assessment of airway inflammation with a panel of non-invasive methods in health care workers (HCWs) with suspected latex allergy with and without current allergic respiratory symptoms about 10 years after the latex ban in German health care facilities. Seventy-seven non-smoking subjects were examined by skin prick test and specific IgE measurements, eNO, IS, and EBC. Sensitivity, specificity, and positive and negative predicted values for relevant biomarkers were calculated using current asthma symptoms as the gold standard. Twenty-nine subjects (38%) reported ongoing asthmatic symptoms (AS). In these subjects the EBC concentrations of nitrogen oxides (NO(x); p=0.027) and leukotriene B(4) (p=0.025) were significantly higher than in subjects without AS. In addition, in the subjects with AS the numbers of eosinophils (p=0.015) and the concentrations of IL-5 (p= 0.021) in IS samples were significantly higher than in the subjects without AS. A good correlation between several inflammatory markers in IS was detected. The maximum Youden Index was reached for IS total eosinophils ≥3.5·10(4) with a test efficiency of 0.72. In conclusion, non-invasive inflammatory monitoring with EBC and IS may assist the diagnosis of allergic asthma. Self-reported current asthmatic symptoms were reflected by eosinophilic inflammation and the best parameter to support the asthma diagnosis is a total number of eosinophils ≥3.5·10(4) in IS.

Topics: Adult; Asthma; Breath Tests; Female; Health Personnel; Humans; Immunoglobulin E; Leukotriene B4; Male; Nitric Oxide; Skin Tests

Asthmatic patients are hypersensitive to the cough-provoking effect of hypertonic aerosols. 15- hydroxyeicosatetraenoic acid (15(S)-HETE) and leukotriene (LT) B4 are asthma-related mediators which can be released upon hypertonic stimuli, and both are potent agonists of the transient receptor potential vanilloid subfamily member 1 (TRPV1), a major cough receptor. Therefore, they are potential mediators for hypertonicity-provoked cough. Twenty-six asthmatic and ten healthy subjects underwent a hypertonic saline cough provocation test. Exhaled breath condensate was collected before and after the test, and the concentrations of 15(S)-HETE and LTB4 were analysed. Neither the baseline concentrations of these mediators nor the saline test-induced changes in them were associated with cough responsiveness to hypertonicity. High baseline 15(S)-HETE was associated with aspirin hypersensitivity and high LTB4 with male sex and large variability in ambulatory peak flow measurements. The TRPV1 agonists 15(S)-HETE and LTB4 seem not to be involved in the cough response to hypertonicity in asthmatic patients.

Topics: Adult; Asthma; Bronchial Provocation Tests; Cough; Female; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Male; Middle Aged; Saline Solution, Hypertonic; TRPV Cation Channels

Polymorphisms spanning genes involved in the production of leukotriene B4 (LTB4) e.g. ALOX5AP and LTA4H are associated with asthma susceptibility, suggesting a role for LTB4 in disease. The contribution of LTB4receptor polymorphism is currently unknown. The aim of this study was to characterise the genes for the two pivotal LTB4 receptors, LTB4R1 and LTB4R2 in lung tissue and determine if polymorphisms spanning these genes are associated with asthma and disease severity.. Rapid amplification of cDNA ends (RACE) was used to characterise the LTB4R1 and LTB4R2 gene structure in lung. The LTB4R1/2 locus on chromosome 14q11.2 was screened for polymorphic variation. Six LTB4R single nucleotide polymorphisms (SNPs) were genotyped in 370 Caucasian asthma families and 299 Adult Asthma Individuals (n=1877 total) and were evaluated for association with asthma and severity (BTS) outcome measures using Family Based Association Test, linear regression and chi square.. LTB4R1 has complex mRNA arrangement including multiple 5'-untranslated exons, suggesting additional levels of regulation. Three potential promoter regions across the LTB4R1/2 locus were identified with some airway cell specificity. 22 SNPs (MAF>0.01) were validated across the LTB4R locus in the Caucasian population. LTB4R1 and LTB4R2 SNPs were not associated with asthma susceptibility, FEV1 or severity.. LTB4R1 and LTB4R2 shows splice variation in the 5'-untranslated region and multiple promoter regions. The functional significance of this is yet to be determined. Both receptor genes were shown to be polymorphic. LTB4R polymorphisms do not appear to be susceptibility markers for the development of asthma in Caucasian subjects.

Topics: 5' Untranslated Regions; Adolescent; Adult; Alternative Splicing; Asthma; Cell Adhesion Molecules; Chromosomes, Human, Pair 14; Exons; Family; Female; Genetic Association Studies; Genetic Predisposition to Disease; Humans; Leukotriene B4; Linear Models; Linkage Disequilibrium; Lung; Male; Middle Aged; Nerve Tissue Proteins; Polymorphism, Single Nucleotide; Receptors, Leukotriene B4; Severity of Illness Index; White People; Young Adult

Allergic asthma is characterized by reversible airway obstruction, lung inflammation, and airway hyperresponsiveness (AHR). Previous studies using leukotriene B(4) (LTB(4)) receptor 1-deficient mice and adoptive transfer experiments have suggested that LTB(4) plays a role in lung inflammation and AHR.. In this study, we used a leukotriene A(4) hydrolase (LTA(4)H) inhibitor as a pharmacological tool to directly examine the role of LTB(4) in a mast cell-dependent murine model of allergic airway inflammation.. We used the forced oscillation technique to test the effects of an LTA(4)H inhibitor dosed during the challenge phase on AHR. Lung tissue and lavage were collected for analysis.. Treatment with an LTA(4)H inhibitor improved multiple parameters encompassing AHR and lung function. Significant decreases in inflammatory leukocytes, cytokines, and mucin were observed in the lung lumen. Serum levels of antigen-specific IgE and IgG1 were also decreased. Labeled antigen uptake by lung dendritic cells and subsequent trafficking to draining lymph nodes and the lung were decreased on LTA(4)H inhibitor treatment. Provocatively, inhibition of LTA(4)H increased lipoxin A(4) levels in lung lavage fluid.. These data suggest that LTB(4) plays a key role in driving lung inflammation and AHR. Mechanistically, we provide evidence that inhibition of LTA(4)H, affects recruitment of both CD4(+) and CD8(+) T cells, as well as trafficking of dendritic cells to draining lymph nodes, and may beneficially modulate other pro- and antiinflammatory eicosanoids in the lung. Inhibition of LTA(4)H is thus a potential therapeutic strategy that could modulate key aspects of asthma.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Cells, Cultured; Cytokines; Epoxide Hydrolases; Immunoglobulin E; Leukotriene B4; Mast Cells; Mice; Mice, Inbred BALB C; Mucins; Ovalbumin

Despite intensive studies focused on the pathophysiology of asthmatic inflammation, little is known about how cross-talk between neuroendocrine and immune systems regulates the inflammatory response during an asthmatic attack. We recently showed corresponding changes of cytokines and leukotriene B4 (LTB4) in brain and lung tissues of antigen-challenged asthmatic rats. Here, we investigated how LTB4 interacts with the neuroendocrine-immune system in regulating antigen-induced asthmatic responses in sensitized guinea pigs.. Ovalbumin-sensitized guinea pigs were challenged by inhalation of antigen. Vehicle, LTB4 or U75302 (a selective LTB4 BLT1 receptor inhibitor) was given via intracerebroventricular injection (i.c.v.) 30 min before challenge. Airway contraction response was evaluated using Penh values before and after antigen challenge. The inflammatory response in lung tissue was evaluated 24 h after challenge. The LTB4 content of lung and brain homogenate preparations was detected by reversed phase high-performance liquid chromatography (RP-HPLC). Plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were measured using ELISA kits.. Antigen challenge impaired pulmonary function and increased inflammatory cell infiltration in lung tissue. These responses could be significantly suppressed by LTB4, 30 ng i.c.v., in ovalbumin-sensitized guinea pigs. LTB4 content of lung and brain homogenates from antigen-challenged guinea pigs was significantly increased. In addition, administration of LTB4 via i.c.v. markedly increased CORT and ACTH level in plasma before antigen challenge, and there were further increases in CORT and ACTH levels in plasma after antigen challenge. U75302, 100 ng i.c.v., completely blocked the effects of LTB4. In addition, U75302, 100 ng via i.c.v. injection, markedly decreased LTB4 content in lung homogenates, but not in brain homogenates.. Increased LTB4 levels in brain during asthmatic attacks down-regulates airway contraction response and inflammation through the BLT1 receptor. Stimulation of the hypothalamic-pituitary-adrenal axis by LTB4 may result in an increase in systemic glucocorticoids which, in turn, would feed back to suppress the asthmatic response.

Topics: Adrenocorticotropic Hormone; Analysis of Variance; Animals; Asthma; Bronchoalveolar Lavage Fluid; Chromatography, Reverse-Phase; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Fatty Alcohols; Glycols; Guinea Pigs; Hydrocortisone; Injections, Intraventricular; Intracranial Hemorrhages; Leukotriene B4; Lung; Ovalbumin; Time Factors

Previously, we have shown that electroacupuncture (EA) in rats decreased eosinophil infiltration into the pulmonary tissue (PT) and in the bronchoalveolar lavage (BAL) in an experimental model of asthma. Th2 cytokines, leukotriene B4 (LTB4) and nitric oxide (NO) are involved in the asthma inflammatory process. The aim of this study was to verify the effects of EA on these asthma mediators. Male Wistar rats were divided into control (C), immobilized (I), sham acupuncture (SA), and acupuncture (A) groups. All rats were sensitized, and EA treatment using clinical acupuncture points was started 24h after antigen priming. EA was done every other day for 2weeks. Subsequently, animals were challenged by inhalation and sacrificed 24h later. At this time, the BAL and lungs were collected and used to analyze cytokine production, LTB4 and NO. The EA increased IL-1 and IFN-gamma and decreased IL-4, IL-10, NO and LTB4 in the BAL and PT compared to the C and SA groups. The presence of eosinophils in the BAL negatively correlated with IL-1 and IFN-gamma production and positively correlated with IL-4 and IL-10 production. Our results show that the beneficial anti-inflammatory action of EA on asthma is related to the balance of the Thl/Th2 response and the reduction of LTB4 and NO. These results suggest that EA therapy could be an important complementary treatment for asthma.

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; Cytokines; Electroacupuncture; Eosinophils; Humans; Inflammation; Leukotriene B4; Male; Nitric Oxide; Rats; Rats, Wistar; T-Lymphocytes, Helper-Inducer; Th1 Cells; Th2 Cells

5-Lipoxygenase (LOX) is an important arachidonic acid-metabolizing enzyme producing leukotrienes and other proinflammatory lipid mediators with potent pathophysiological functions in asthma and other inflammatory diseases. 4-(3-(4-(1-Methyl-1H-pyrazol-5-yl)phenylthio)phenyl)-tetrahydro-2H-pyran-4-carboxamide (PF-4191834) is a novel, selective non-redox 5-lipoxygenase inhibitor effective in inflammation and pain. In vitro and in vivo assays were developed for the evaluation of a novel 5-LOX inhibitor using conditions of maximal enzyme activity. PF-4191834 exhibits good potency in enzyme- and cell-based assays, as well as in a rat model of acute inflammation. Enzyme assay results indicate that PF-4191834 is a potent 5-LOX inhibitor, with an IC(50) = 229 +/- 20 nM. Furthermore, it demonstrated approximately 300-fold selectivity for 5-LOX over 12-LOX and 15-LOX and shows no activity toward the cyclooxygenase enzymes. In addition, PF-4191834 inhibits 5-LOX in human blood cells, with an IC(80) = 370 +/- 20 nM. This inhibitory concentration correlates well with plasma exposures needed for in vivo efficacy in inflammation in models of inflammatory pain. The combination of potency in cells and in vivo, together with a sustained in vivo effect, provides PF-4191834 with an overall pharmacodynamic improvement consistent with once a day dosing.

Topics: Animals; Asthma; Chromatography, Liquid; Disease Models, Animal; Humans; Inflammation; Leukocytes; Leukotriene B4; Lipoxygenase Inhibitors; Male; Mass Spectrometry; Oxidation-Reduction; Pain; Pyrazoles; Rats; Rats, Inbred Lew; Rats, Sprague-Dawley; Spectrophotometry; Sulfides

Basic and clinical studies suggest that hypothalamic-pituitary-adrenal (HPA) axis is the neuroendocrine-immune pathway that functionally regulates the chronic inflammatory disease including asthma. Our previous studies showed corresponding changes of cytokines and leukotriene B4 (LTB4) between brain and lung tissues in antigen-challenged asthmatic rats. Here, we investigated how the increased LTB4 level in brain interacts with HPA axis in regulating antigen-induced asthmatic response in sensitized rats.. Ovalbumin-sensitized rats were challenged by inhalation of antigen. Rats received vehicle, LTB4 or U75302 (a selective LTB4 BLT1 receptor inhibitor) was given via intracerebroventricular injection (i.c.v) 30 min before challenge. Lung resistance (RL) and dynamic lung compliance (Cdyn) were measured before and after antigen challenge. Inflammatory response in lung tissue was assessed 24 h after challenge. Expression of CRH mRNA and protein in hypothalamus were evaluated by RT-PCR and Western Blot, and plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were measured using the ELISA kits.. Antigen challenge decreased pulmonary function and induced airway inflammation, evoked HPA axis response in sensitized rats. Administration of LTB4 via i.c.v markedly attenuated airway contraction and inflammation. Meanwhile, LTB4 via i.c.v markedly increased CORT and ACTH level in plasma before antigen challenge, and followed by further increases in CORT and ACTH levels in plasma after antigen challenge in sensitized rats. Expression of CRH mRNA and protein in hypothalamus were also significantly increased by LTB4 via i.c.v in sensitized rats after antigen challenge. These effect were completely blocked by pre-treatment with BLT1 receptor antagonist U75302 (10 ng), but not by BLT2 antagonist LY255283.. LTB4 administered via i.c.v down-regulates the airway contraction response and inflammation through activation of the HPA axis via its BLT1 receptor. This study expands our concept of the regulatory role of intracranial inflammatory mediators in inflammatory diseases including asthma. The favourable effects of LTB4 on the HPA axis may help to explain the phenomenon of self-relief after an asthmatic attack.

Topics: Adrenocorticotropic Hormone; Airway Resistance; Animals; Asthma; Blotting, Western; Corticotropin-Releasing Hormone; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Fatty Alcohols; Female; Glycols; Hypothalamo-Hypophyseal System; Hypothalamus; Inflammation Mediators; Injections, Intraventricular; Leukotriene B4; Lung; Lung Compliance; Male; Ovalbumin; Pituitary-Adrenal System; Pulmonary Eosinophilia; Rats; Rats, Sprague-Dawley; Receptors, Leukotriene B4; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

An imbalance in the generation of pro-inflammatory leukotrienes, and counter-regulatory lipoxins is present in severe asthma. We measured leukotriene B4 (LTB4), and lipoxin A4 (LXA4) production by alveolar macrophages (AMs) and studied the impact of corticosteroids.. AMs obtained by fiberoptic bronchoscopy from 14 non-asthmatics, 12 non-severe and 11 severe asthmatics were stimulated with lipopolysaccharide (LPS,10 microg/ml) with or without dexamethasone (10(-6)M). LTB4 and LXA4 were measured by enzyme immunoassay.. LXA4 biosynthesis was decreased from severe asthma AMs compared to non-severe (p < 0.05) and normal subjects (p < 0.001). LXA4 induced by LPS was highest in normal subjects and lowest in severe asthmatics (p < 0.01). Basal levels of LTB4 were decreased in severe asthmatics compared to normal subjects (p < 0.05), but not to non-severe asthma. LPS-induced LTB4 was increased in severe asthma compared to non-severe asthma (p < 0.05). Dexamethasone inhibited LPS-induced LTB4 and LXA4, with lesser suppression of LTB4 in severe asthma patients (p < 0.05). There was a significant correlation between LPS-induced LXA4 and FEV1 (% predicted) (r(s) = 0.60; p < 0.01).. Decreased LXA4 and increased LTB4 generation plus impaired corticosteroid sensitivity of LPS-induced LTB4 but not of LXA4 support a role for AMs in establishing a pro-inflammatory balance in severe asthma.

Topics: Adrenal Cortex Hormones; Adult; Asthma; Bronchoscopy; Case-Control Studies; Dexamethasone; Down-Regulation; Female; Forced Expiratory Volume; Humans; Immunoenzyme Techniques; Inflammation Mediators; Leukotriene B4; Lipopolysaccharides; Lipoxins; Macrophages, Alveolar; Male; Middle Aged; Severity of Illness Index; Young Adult

Leukotrienes and isoprostanes are biomarkers of airway inflammation and oxidative stress that can be detected in exhaled breath condensate (EBC). The aim of this study was to evaluate leukotriene B4 (LTB4) and 8-isoprostane levels in EBC of healthy and asthmatic children with episodic and moderate persistent asthma.. EBC was collected from 62 children aged 6 to 14 years: 22 healthy children, 30 patients with episodic asthma, and 10 patients with moderate persistent asthma, without preventive treatment at the time of enrolment.. LTB concentrations were higher in children with asthma than in healthy controls (50.7 pg/mL vs. 13.68 pg/mL, P < .011). The same was true for children with moderate persistent asthma compared to children with episodic asthma (146.9 pg/mL vs. 18.85 pg/mL, P < .0001), children with moderate persistent asthma compared to healthy controls (146.9 pg/mL vs. 13.68 pg/mL, P < .0001), and children with episodic asthma compared to healthy controls (P, nonsignificant). EBC concentrations of 8-isoprostane were higher in asthmatic than in healthy children (18.3 pg/mL vs. 6.59 pg/mL, P < .026). They were also increased in children with moderate persistent asthma compared to those with episodic asthma (36.25 pg/mL and 12.28 pg/mL, P < .012), and in children with moderate persistent asthma and episodic asthma compared to healthy controls (36.25 pg/mL vs. 6.59 pg/mL [P < .0001] and 12.28 pg/mL versus 6.59 pg/mL [P < .0001], respectively).. LTB4 and 8-isoprostane concentrations were increased in asthmatic children compared to healthy individuals, with differences detected for 2 degrees of asthma severity. Our findings suggest that EBC is a noninvasive method for airway inflammation and oxidative stress assessment.

Topics: Adolescent; Asthma; Breath Tests; Child; Dinoprost; Female; Humans; Leukotriene B4; Male; Nitric Oxide; Oxidative Stress; Respiratory Function Tests; Statistics, Nonparametric

The purpose of the study was to determine which of the active constituents of fish oil, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), is most effective in suppressing proinflammatory mediator generation and cytokine expression from LPS-stimulated human asthmatic alveolar macrophages (AMphi).. The AMphi were obtained from twenty-one asthmatic adults using fiberoptic bronchoscopy. Cells were pretreated with DMEM, pure EPA, an EPA-rich media (45% EPA/10% DHA), pure DHA, a DHA-rich media (10% EPA/50% DHA) or Lipovenos (n-6 PUFA), and then exposed to Dulbecco's Modified Eagle's Medium (DMEM) (-) or LPS (+). Supernatants were analyzed for leukotriene (LT)B(4), prostaglandin (PG)D(2), tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta production. Detection of TNF-alpha and IL-1beta mRNA expression levels was quantified by reverse transcriptase polymerase chain reaction.. 120 microM pure EPA and EPA-rich media significantly (p<0.05) suppressed TNF-alpha and IL-1beta mRNA expression and the production of LTB(4), PGD(2) and TNF-alpha and IL-1beta in LPS-stimulated primary AMphi cells obtained from asthmatic patients to a much greater extent than 120 microM pure DHA and DHA-rich media respectively.. This study has shown for the first time that EPA is a more potent inhibitor than DHA of inflammatory responses in human asthmatic AMphi cells.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Asthma; Cell Line; Docosahexaenoic Acids; Dose-Response Relationship, Drug; Eicosapentaenoic Acid; Humans; Inflammation; Interleukin-1beta; Leukotriene B4; Lipopolysaccharides; Macrophages, Alveolar; Prostaglandin D2; Reverse Transcriptase Polymerase Chain Reaction; Tumor Necrosis Factor-alpha

Allergic rhinitis and bronchial asthma can coexist and affect each other.. To investigate the relationship between the postseasonal increase in the concentration of leukotriene (LT) B4 and LTE4 in exhaled breath condensate (EBC) and bronchial responsiveness to methacholine (BRM) in patients with seasonal allergic rhinitis (SAR).. In 28 patients with SAR and 50 healthy study patients, the leukotrienes were measured in EBC during and after the pollen season by gas chromatography/mass spectrometry. The BRM was determined after the pollen season.. In 7 patients with SAR, significantly increased concentrations of both the leukotrienes were found in EBC during and 5 months after the pollen season. The following seasonal and postseasonal median values were measured in patients with SAR in comparison with control patients: LTB4: 131 and 90 pg/mL vs 80 and 79 pg/mL, P < .001 and P = .03, respectively; LTE4: 122 and 86 pg/mL vs 76 and 74 pg/mL, P < .001 and P = .02, respectively. Five months after the pollen season, the concentrations of LTB4 and LTE4 decreased with respect to their seasonal values (90 and 86 pg/mL, respectively, P < .001, for both leukotrienes). In 7 patients with SAR and leukotriene levels exceeding the reference limits, significantly increased BRM was also found (LTB4: P = .02; LTE4: P = .002).. The seasonal and postseasonal increases in LTB4 and LTE4 concentrations in EBC of the patients with SAR correlated significantly with the later increase in BMR. This relationship could provide a useful predictive parameter for early inflammatory processes in the lower airways of patients with allergic rhinitis.

Topics: Adult; Anti-Asthmatic Agents; Asthma; Bronchi; Exhalation; Female; Humans; Leukotriene B4; Leukotriene E4; Male; Methacholine Chloride; Middle Aged; Reference Standards; Rhinitis, Allergic, Seasonal; Young Adult

Statins have been proposed as a novel treatment of respiratory diseases. To determine the beneficial effects of statins on allergic bronchial asthma, the effect of systemic treatment with lovastatin on antigen-induced airway inflammation was investigated.. Male BALB/c mice were used.. Mice were sensitized and repeatedly challenged with ovalbumin (OA) antigen to induce asthmatic response. Animals were also treated with lovastatin (4 mg/kg/day, i.p.) once a day prior to and during the antigen inhalation period.. Inflammatory cell counts and levels of interleukin (IL)-4, IL-13, eotaxin, thymus and activation-regulated chemokine and leukotriene B(4) (LTB(4)) in bronchoalveolar lavage (BAL) fluids were measured.. Significant increases in eosinophils and levels of the T helper 2 cytokines, chemokines and LTB(4) in BAL fluids in association with the increments of total and OA-specific immunoglobulin E (IgE) in sera were observed in the repeatedly antigen-challenged mice. The airway eosinophilia was ameliorated by lovastatin, whereas it had no significant effect on the levels of these inflammatory mediators or IgE.. Lovastatin may be beneficial for the treatment of allergic inflammatory diseases in the airways, such as allergic bronchial asthma.

Topics: Animals; Anti-Inflammatory Agents; Antigens; Asthma; Bronchoalveolar Lavage Fluid; Cell Count; Cytokines; Disease Models, Animal; Eosinophilia; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Immunoglobulin E; Inflammation Mediators; Leukotriene B4; Lovastatin; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Pneumonia

The potent and selective 5-lipoxygenase-activating protein leukotriene synthesis inhibitor 3-[3-tert-butylsulfanyl-1-[4-(6-methoxy-pyridin-3-yl)-benzyl]-5-(pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (11j) is described. Lead optimization was designed to afford compounds with superior in vitro and in vivo inhibition of leukotriene synthesis in addition to having excellent pharmacokinetics and safety in rats and dogs. The key structural features of these new compounds are incorporation of heterocycles on the indole N-benzyl substituent and replacement of the quinoline group resulting in compounds with excellent in vitro and in vivo activities, superior pharmacokinetics, and improved physical properties. The methoxypyridine derivative 11j has an IC(50) of 4.2 nM in a 5-lipoxygenase-activating protein (FLAP) binding assay, an IC(50) of 349 nM in the human blood LTB(4) inhibition assay, and is efficacious in a murine ovalbumin model of allergen-induced asthma. Compound 11j was selected for clinical development and has successfully completed phase 1 trials in healthy volunteers.

Topics: 5-Lipoxygenase-Activating Proteins; Animals; Asthma; Carrier Proteins; Dogs; Drug-Related Side Effects and Adverse Reactions; Heterocyclic Compounds; Humans; Indoles; Inhibitory Concentration 50; Leukotriene B4; Membrane Proteins; Mice; Propionates; Protein Binding; Rats; Structure-Activity Relationship

Leukotrienes (LTs) are proinflammatory lipid mediators synthesized by the conversion of arachidonic acid (AA) to LTA(4) by the enzyme 5-lipoxygenase (5-LO) in the presence of 5-LO-activating protein (FLAP). 3-[3-tert-Butylsulfanyl-1-[4-(6-methoxy-pyridin-3-yl)-benzyl]-5-(pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (AM103) is a novel selective FLAP inhibitor in development for the treatment of respiratory conditions such as asthma. In a rat ex vivo whole-blood calcium ionophore-induced LTB(4) assay, AM103 (administered orally at 1 mg/kg) displayed >50% inhibition for up to 6 h with a calculated EC(50) of approximately 60 nM. When rat lung was challenged in vivo with calcium ionophore, AM103 inhibited LTB(4) and cysteinyl leukotriene (CysLT) production with ED(50) values of 0.8 and 1 mg/kg, respectively. In this model, the EC(50) derived from plasma AM103 was approximately 330 nM for inhibition of both LTB(4) and CysLT. In an acute inflammation setting, AM103 displayed dose-dependent inhibition of LTB(4), CysLT, and plasma protein extravasation induced by peritoneal zymosan injection. In a model of chronic lung inflammation using ovalbumin-primed and challenged BALB/c mice, AM103 reduced the concentrations of eosinophil peroxidase, CysLTs, and interleukin-5 in the bronchoalveolar lavage fluid. Finally, AM103 increased survival time in mice exposed to a lethal intravenous injection of platelet-activating factor. In summary, AM103 is a novel, potent and selective FLAP inhibitor that has excellent pharmacodynamic properties in vivo and is effective in animal models of acute and chronic inflammation and in a model of lethal shock.

Topics: 5-Lipoxygenase-Activating Proteins; Acute Disease; Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Asthma; Carrier Proteins; Chronic Disease; Disease Models, Animal; Dose-Response Relationship, Drug; Extravasation of Diagnostic and Therapeutic Materials; Female; Humans; Indoles; Inflammation; Leukotriene B4; Male; Membrane Proteins; Mice; Mice, Inbred BALB C; Pneumonia; Propionates; Rats; Rats, Sprague-Dawley; Zymosan

To explore the effects and the mechanism of Wuwei Dilong Decoction (Schisandra Fruit and Earthworm Decoction) for treatment of asthma.. The asthma guinea pig model was established with spray of ovalbumin (OVA). Fifteen days later, the guinea pigs were administered by intra-gastric perfusion of Wuwei Dilong Decoction once a day for 8 consecutive days. Blood samples were taken for testing the total leucocytes, eosinophil (EOS), lymphocytes, interferon-gamma (IFN-gamma) and leukotriene B4 (LTB4).. In the asthma model group, the total leucocytes, EOS and lymphocytes were all increased, with significant differences as compared with the different dosage Wuwei Dilong Decoction groups (P < 0.01 or P < 0.05). The serum LTB4 in the asthma model group was significantly increased and IFN-gamma decreased. After administration of Wuwei Dilong Decoction of the large, medium and small dosages, LTB4 decreased, while IFN-gamma increased (P < 0.05 or P < 0.01).. Wuwei Dilong Decoction can inhibit infiltration and diffusion of the inflammatory cells in the asthma model guinea pigs, and regulate LTB4 and IFN-gamma, which is probably one of the important mechanisms of Wuwei Dilong Decoction for relieving asthma.

Topics: Analysis of Variance; Animals; Asthma; Disease Models, Animal; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Enzyme-Linked Immunosorbent Assay; Eosinophils; Guinea Pigs; Interferon-gamma; Leukocyte Count; Leukocytes; Leukotriene B4; Lymphocytes; Medicine, Chinese Traditional; Random Allocation; Treatment Outcome

Leukotrienes (LTs) have been identified as central mediators in asthma and allergy. Pharmacological inhibition of cysteinyl-LT activity improves asthma symptoms and control. Accumulating evidence suggests a role for the dihydroxy leukotriene LTB(4) in airway disease. LTA(4) hydrolase and 5-lipoxygenase activating protein have key roles in LTB(4) production. Single nucleotide polymorphism (SNPs) and haplotypes spanning the LTA4H and ALOX5AP genes have been associated with LTB(4) production and myocardial infarction (MI).. To assess the contribution of LTA4H and ALOX5AP polymorphism to asthma and allergy susceptibility.. Three hundred and forty-one Caucasian families (two asthmatic siblings) were genotyped for eight SNPs spanning ALOX5AP and five SNPs spanning LTA4H. Association analyses of asthma and related phenotypes (total IgE, atopy, bronchial hyper-responsiveness, FEV(1)) were undertaken using the Family Based Association Test.. Single point analyses identified association (P < 0.05) between SNPs SG13S114, SG13S89, SG13S41 (ALOX5AP), rs1978331 (LTA4H) and asthma and/or related phenotypes. Haplotype analyses using all LTA4H SNPs identified a single key risk haplotype for the development of asthma (P = 0.006) and related phenotypes (P = 0.042-0.005). Haplotype analyses using all ALOX5AP SNPs identified several asthma and atopy risk and protective haplotypes. There was limited correlation with previously identified MI risk haplotypes in both genes. Carriers of both ALOX5AP SG13S41 and LTA4H rs1978331 alleles had an increased risk of developing asthma (OR 2.17, CI 1.41-3.32).. These data provide evidence for the role of SNPs spanning the ALOX5AP and LTA4H genes in asthma and atopy susceptibility in the Caucasian population and support a role for LTB(4) in disease pathogenesis.

Topics: Adolescent; Adult; Arachidonate 5-Lipoxygenase; Asthma; Child; Epoxide Hydrolases; Female; Humans; Hypersensitivity; Leukotriene B4; Male; Polymorphism, Single Nucleotide; Risk Factors

Exercise-induced bronchospasm (EIB) occurs in athletes with and without asthma. Studies have suggested an inflammatory basis for EIB in asthmatics; however whether inflammation plays a similar role in EIB in athletes without asthma remains unclear. Our objective was to determine whether there is evidence of an inflammatory basis for exercise-induced bronchospasm occurring in non-asthmatic athletes. Ninety-six athletes without asthma from varsity college teams underwent eucapnic voluntary hyperventilation testing. Sputum was induced from subjects with hypertonic saline inhalation post-eucapnic voluntary hyperventilation testing and was analyzed with enzyme-linked immunosorbent assays for IL-5, IL-8, IL-13, cysteinyl-leukotrienes, prostaglandin E2, histamine, leukotriene B4, and thromboxane B2. In addition, inflammatory (neutrophils, lymphocytes, eosinophils, and macrophages) and epithelial cell counts in sputum were recorded. Multivariate regression modeling showed a significant correlation between concentrations of select inflammatory mediators after eucapnic voluntary hyperventilation testing and severity of EIB. Means of the log-transformed concentrations of inflammatory mediators in EIB-positive athletes were significantly higher post-eucapnic voluntary hyperventilation than in EIB-negative athletes. Similar findings were not demonstrated with inflammatory cells. Concentrations of inflammatory mediators are higher in EIB-positive athletes than in EIB-negative athletes without asthma after eucapnic voluntary hyperventilation testing. The severity of EIB in our cohort also is significantly correlated with increased concentrations of select inflammatory mediators suggesting a potential inflammatory basis for EIB in athletes without asthma.

Topics: Adult; Age Factors; Asthma; Asthma, Exercise-Induced; Bronchial Hyperreactivity; Cohort Studies; Dinoprostone; Female; Histamine; Humans; Incidence; Inflammation; Inflammation Mediators; Leukotriene B4; Male; Multivariate Analysis; Probability; Respiratory Function Tests; Risk Assessment; Sensitivity and Specificity; Sex Factors; Sports; Sputum; Thromboxane B2

Platelets are involved in the pathogenesis of aspirin-induced asthma (AIA). AIA patients suffer from an active disease despite avoidance of aspirin, and it has been suggested that administration of aspirin to these patients increases the generation of immediate oxygen products of arachidonic acid, 12-hydroperoxyeicosatetraenoic acid (12-HPETE), in their platelets. 12-HPETE further activates the 5-lipoxygenase of leukotriene B4-producing inflammatory macrophages precipitating an acute asthmatic attack. Glutathione peroxidase (GPX) has the antioxidant capacity to reduce 12-HPETE, and thus modulate the arachidonic acid metabolic cascade. There is evidence that selenium (Se) nutrition can influence asthma but Se status in AIA patients has not received much attention.. We measured Se concentrations and GPX activities in platelets and plasma from 13 patients with AIA. Age- and sex-matched healthy individuals served as the control group.. Patients with AIA had significantly higher median platelet Se concentration (102 ng/mg platelet protein) when compared with controls (49 ng/mg platelet protein, P = 0.003). Plasma Se concentrations in patients with AIA and controls were not significantly different (P = 0.59). Median platelet GPX activity was significantly higher in patients with AIA (102.7 mU/mg platelet protein) than in controls (66 mU/mg protein) (P = 0.05). The patient and control groups when combined showed weak, but significant correlation between platelet Se concentration and platelet GPX activity (r = 0.44; P = 0.03).. It is proposed that the higher platelet Se concentration observed in AIA patients contributed to the higher platelet GPX activity seen in these patients. Such an enhanced antioxidant defence system might represent an adaptive response to protect against increasing free radical production by inflammatory cells in AIA and help decelerate ongoing respiratory hypersensitivity.

Topics: Adult; Aged; Antioxidants; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Aspirin; Asthma; Female; Free Radicals; Humans; Leukotriene B4; Leukotrienes; Macrophages; Male; Middle Aged; Selenium

A diagnosis of aspirin-intolerant asthma requires aspirin provocation in specialist clinics. Urinary leukotriene E(4) (LTE(4)) is increased in aspirin-intolerant asthma. A study was undertaken to investigate new biomarkers of aspirin intolerance by comparing basal levels of cysteinyl-leukotrienes (CysLTs) and leukotriene B(4) (LTB(4)) in saliva, sputum and ex vivo stimulated blood in subjects with aspirin-intolerant and aspirin-tolerant asthma. The effects of aspirin- and allergen-induced bronchoconstriction on leukotriene levels in saliva and ex vivo stimulated blood were also compared with the effects of the provocations on urinary mediators.. Induced sputum, saliva, urine and blood were obtained at baseline from 21 subjects with asthma. At a separate visit, 11 subjects showed a positive response to lysine-aspirin inhalation and 10 were aspirin tolerant. Saliva, blood and urine were also collected on the provocation day. Analyses of CysLTs and LTB(4) and the prostaglandin D(2) metabolite 9alpha,11beta-prostaglandin F(2) were performed and the fraction of exhaled nitric oxide was measured.. Subjects with aspirin-intolerant asthma had higher exhaled nitric oxide levels and higher baseline levels of CysLTs in saliva, sputum, blood ex vivo and urine than subjects with aspirin-tolerant asthma. There were no differences in LTB(4) levels between the groups. Levels of urinary LTE(4) and 9alpha,11beta-prostaglandin F(2) increased after aspirin provocation whereas leukotriene levels in saliva and ex vivo stimulated blood did not increase.. These findings support a global and specific increase in CysLT production in aspirin-intolerant asthma. Measurement of CysLTs in saliva has the potential to be a new and convenient non-invasive biomarker of aspirin-intolerant asthma.

Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Asthma; Biomarkers; Cysteine; Dinoprost; Drug Hypersensitivity; Female; Humans; Leukotriene B4; Leukotrienes; Male; Middle Aged; Saliva; Sputum; Uteroglobin

Cysteinyl-leukotrienes are important pro-inflammatory mediators in bronchial asthma (BA) and are derived from arachidonic acid by the action of 5-lipoxygenase. We identified a novel polymorphism, c.760 G>A (E254K), in exon 6 of the 5-lipoxygenase gene (5-LO). This substitution was detected in 11 out of 180 patients with BA, but not in any of the 150 non-allergic subjects. The frequency of c.760 G>A showed a significant difference between BA and non-allergic subjects (P=0.0007). The c.760 G>A polymorphism existed at the surface edge of the C-terminal catalytic domain, and the E-to-K substitution changed the charge of the side chain from negative to positive. Thus, our results suggest that E254K in the 5-LO might be associated with BA.

Topics: Arachidonate 5-Lipoxygenase; Asthma; Base Sequence; Child; DNA Mutational Analysis; Female; Gene Expression Regulation, Enzymologic; Gene Frequency; Genetic Predisposition to Disease; Glutamic Acid; Humans; Ionomycin; Leukotriene B4; Leukotriene E4; Lysine; Male; Models, Molecular; Molecular Sequence Data; Neutrophils; Polymorphism, Genetic; RNA, Messenger; Structural Homology, Protein

There is increasing evidence that both neutrophilic and eosinophilic inflammation persist in the airways of patients with severe asthma. We have reported a positive relationship between the concentrations of eosinophils and neutrophils in sputum from severe asthmatics, suggesting a possible role of eosinophils in regulating neutrophilic inflammation. The aim of this study was to investigate whether activated eosinophils modify the trans-basement membrane migration (TBM) of neutrophils.. Eosinophils and neutrophils were isolated from peripheral blood drawn from healthy donors. The TBM of neutrophils in response to a variety of chemoattractants was evaluated in the presence or absence of eosinophils by using the chambers with a Matrigel-coated Transwell insert.. As expected, eotaxin (10 nM) and RANTES (10 nM), but not IL-8 (10 nM), induced the TBM of eosinophils. On the contrary, only IL-8 induced the TBM of neutrophils. When eosinophils were coincubated with neutrophils and stimulated with IL-8, the TBM of eosinophils was significantly augmented. On the other hand, when neutrophils were coincubated with eosinophils and stimulated with eotaxin or RANTES, the TBM of neutrophils was not modified.. Neutrophils migrated by IL-8 may lead eosinophils to accumulate in the airways of patients with severe asthma. On the other hand, it is unlikely that eosinophils migrated by chemoattractants such as CC chemokines regulate neutrophilic inflammation.

Topics: Adult; Asthma; Basement Membrane; Cells, Cultured; Chemokine CCL11; Chemokine CCL5; Chemokines, CC; Chemotaxis, Leukocyte; Eosinophils; Female; Humans; In Vitro Techniques; Interleukin-8; Leukotriene B4; Male; Neutrophils; Pulmonary Eosinophilia

We have recently shown that the leukotriene B(4) (LTB(4))-BLT1 pathway is important in early effector T-cell recruitment in mouse models of inflammation. Here we characterize the phenotype and function of human peripheral blood BLT1(+) T cells in health and illustrate their involvement in asthma and acute infection. In healthy individuals, BLT1(+) T cells are a rare peripheral blood T-cell population enriched for the activation markers CD38 and HLA-DR. Compared with BLT1(-) T cells, a larger proportion of peripheral blood BLT1(+) T cells express the effector cytokines IFNgamma and IL-4 and inflammatory chemokine receptors, CCR1, CCR2, CCR6, and CXCR1. Consequently, in healthy individuals peripheral blood BLT1(+) T cells are a rare antigen-primed T-cell subset with unique phenotypic, migratory, and functional properties. BLT1 expression on T cells is tightly regulated by inflammation and only transiently expressed after naive T-cell activation by dendritic cells. Although rare in the peripheral blood of healthy individuals, BLT1(+) T cells are markedly increased in frequency in the peripheral blood in response to acute Epstein-Barr virus (EBV) infection and moderately increased in the airways of asymptomatic allergic asthmatics. Our studies provide novel insights into the LTB(4)-BLT1 lipid chemoattractant pathway in human T-cell responses, and how it may link innate and adaptive immunity.

Topics: Acute Disease; ADP-ribosyl Cyclase 1; Asthma; Bronchoalveolar Lavage Fluid; Case-Control Studies; Cells, Cultured; Epstein-Barr Virus Infections; Herpesvirus 4, Human; HLA-DR Antigens; Humans; Inflammation; Interferon-gamma; Interleukin-4; Leukotriene B4; Lymphocyte Activation; Protein Serine-Threonine Kinases; Receptors, CCR2; Receptors, CCR6; Receptors, Chemokine; Receptors, Interleukin-8A; Receptors, Leukotriene B4; Receptors, Purinergic P2; T-Lymphocytes

Exhaled breath condensate (EBC) pH appears to be a robust measure of asthma. However, the association between EBC pH and clinical factors and airway inflammatory markers remains unclear. The objectives of this study were to investigate the factors determining EBC pH in asthmatic children, and the reproducibility and effects of collection devices on EBC pH in nine healthy, nonsmoking adults. EBC was collected once from asthmatic children using EcoScreen, and from adults over 3 consecutive days using both RTubes and EcoScreen. EBC pH was measured immediately in non-deaerated samples by microelectrode pH meter. Concentrations of 8-isoprostane, cysteinyl leukotrienes (cys-LT), and leukotriene B4 (LTB4) were measured using enzyme immunoassay. Exhaled nitric oxide concentration (FeNO) was measured by chemiluminescence. Fifty-eight asthmatics (16 intermittent, 12 mild persistent, and 30 moderate-to-severe persistent) were recruited. EBC pH was lower among patients with moderate-to-severe persistent than intermittent asthma (P = 0.046). This marker correlated inversely with disease severity score (rho = -0.276, P = 0.036), but not FeNO or other EBC biomarkers. Bland-Altman analyses found pH but not other EBC biomarkers to be reproducible, which were confirmed by its low coefficient of variation (2.7%; range, 0.4-5.2%). There was poor correlation between pH in EBC collected by RTube and EcoScreen (rho = 0.059, P = 0.784). Factor analysis selected four factors that explained 67.5% of the total variance, and EBC pH clustered with both cys-LT and LTB4. In conclusion, our results suggest that pH in non-deaerated EBC is influenced by asthma severity in children. EBC pH measurement is reproducible, but is dependent on the collection devices used.

Topics: Adolescent; Adult; Asthma; Biomarkers; Breath Tests; Child; Cysteine; Dinoprost; Factor Analysis, Statistical; Female; Forced Expiratory Volume; Humans; Hydrogen-Ion Concentration; Immunoenzyme Techniques; Leukotriene B4; Leukotrienes; Luminescent Measurements; Male; Nitric Oxide; Reproducibility of Results; Severity of Illness Index

Neutrophilic inflammation observed with severe asthma is often associated with interleukin-8 (IL-8). Neutrophils can secrete a variety of mediators that may augment the migration of eosinophils. We have reported a positive correlation between the concentrations of neutrophils and eosinophils in sputum from subjects with severe asthma, suggesting a possible role of neutrophils in regulating eosinophilic inflammation. The aim of this study was to investigate whether neutrophils stimulated with IL-8 modify the trans-basement membrane migration (TBM) of eosinophils. Eosinophils and neutrophils were isolated from peripheral blood drawn from healthy donors or subjects with mild asthma. The TBM of eosinophils in response to IL-8 was evaluated in the presence or absence of neutrophils using the chambers with a Matrigel-coated transwell insert. Neither IL-8 alone nor the presence of neutrophils alone induced the TBM of eosinophils. However, when eosinophils were coincubated with neutrophils and stimulated with IL-8, the TBM of eosinophils was significantly augmented. This augmented TBM of eosinophils was inhibited by a matrix metalloproteinase-9 inhibitor, a leukotriene B4 receptor antagonist, platelet-activating factor antagonists, or an anti-TNF-alpha monoclonal antibodies. These results suggest that neutrophils migrated in response to IL-8 may lead eosinophils to accumulate in the airways of asthma and possibly aggravate this disease.

Topics: Adult; Antibodies, Monoclonal; Asthma; Azepines; Basement Membrane; Chemotaxis, Leukocyte; Coculture Techniques; Collagen; Culture Media, Conditioned; Drug Combinations; Eosinophils; Humans; Interleukin-8; Laminin; Leukotriene B4; Matrix Metalloproteinase 9; Neutrophil Activation; Neutrophils; Paracrine Communication; Platelet Activating Factor; Protease Inhibitors; Proteoglycans; Pulmonary Eosinophilia; Triazoles; Tumor Necrosis Factor-alpha

An increasing prevalence of allergic diseases, such as atopic dermatitis, allergic rhinitis and bronchial asthma, has been noted worldwide. Allergic asthma strongly correlates with airway inflammation caused by the unregulated production of cytokines secreted by allergen-specific type-2 T helper (Th2) cells. This study aims to explore the therapeutic effect of the airway gene transfer of IL-12, IL-10 and TGF-beta on airway inflammation in a mouse model of allergic asthma.. BALB/c mice were sensitized to ovalbumin (OVA) by intraperitoneal injections with OVA and challenged by nebulized OVA. Different cytokine gene plasmids or non-coding vector plasmids were instilled daily into the trachea up to one day before the inhalatory OVA challenge phase.. Intratracheal administration of IL-10, IL-12 or TGF-beta can efficiently inhibit antigen-induced airway hyper-responsiveness and is able to largely significantly lower the number of eosinophils and neutrophils in bronchoalveolar lavage fluid of ovalbumin (OVA) sensitized and challenged mice during the effector phase. Furthermore, the effect of IL-10 plasmids is more remarkable than any other cytokine gene plasmid. On the other hand, local administration of IL-4 gene plasmids before antigen challenge can induce severe airway hyper-responsiveness (AHR) and airway eosinophilia.. Our data demonstrated that anti-inflammatory cytokines, particularly IL-10, have the therapeutic potential for the alleviation of airway inflammation in murine model of asthma.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Chemokine CCL11; Chemokines, CC; Disease Models, Animal; Female; Gene Transfer Techniques; Interleukin-10; Interleukin-12; Interleukin-4; Leukotriene B4; Mice; Mice, Inbred BALB C; Ovalbumin; Pulmonary Eosinophilia; Transforming Growth Factor beta

Inhaled endotoxin is known to induce airway inflammation, causing bronchial hyperreactivity.. We characterized the response to lipopolysaccharide-inhalation by measuring exhaled nitric oxide (eNO) and inflammatory mediators.. A total of 43 adult volunteers (13 asthmatics, 30 healthy controls) inhaled stepwise LPS every 30 min up to a cumulative dose of 100 microg (2.5, 10.5, 42, 45 microg). After each provocation and up to 24 h later, FEV(1) was determined; the procedure was stopped when FEV(1) declined more than 12.5%. We measured eNO, leucocytes, eosinophils, polymorphonuclear neutrophils (PMNs), C-reactive protein (CrP), lipopolysaccharide binding protein (LBP), eosinophilic cationic protein (ECP), leucotriene B4 (LTB4), thromboxane B2 (TXB2), and body temperature.. Initial eNO values were higher in asthmatics (P < 0.01), but only increased in an asthmatic subgroup. Marked differences were observed in the systemic response to LPS inhalation. Significant increases were found for CrP, LBP, and PMNs. There was no correlation between FEV(1) decrease and basal eNO levels.. Inhalation of endotoxin was followed by clinical and laboratory signs of systemic inflammation, with asthmatics responding to the challenge similar as healthy subjects. Bronchial eNO increased only temporarily in asthmatics.

Topics: Administration, Inhalation; Adult; Animals; Asthma; Biomarkers; Body Size; Body Weight; C-Reactive Protein; Eosinophils; Female; Humans; Inflammation; Leukocytes; Leukotriene B4; Leukotrienes; Lipopolysaccharides; Male; Mites; Neutrophils; Nitric Oxide Synthase Type III; Reference Values

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

Lipoxins and 15-epi-lipoxins are lipid mediators that modulate leukocyte trafficking and promote the inflammation resolution. They are produced by different enzymatic pathways. Patients with severe asthma present ongoing airway inflammation despite chronic long-term treatment including oral glucocorticoids.. The aim of this study was to assess the presence of proinflammatory and anti-inflammatory mediators in the supernatants of induced sputum.. Induced sputum supernatants were collected from 10 normal subjects; 12 subjects with mild, 15 with moderate, and 24 with severe asthma; and 13 patients with chronic obstructive pulmonary disease. First, we validated the measurements of IL-8, leukotriene B 4 , lipoxin A 4 , and 15-epi-lipoxin A 4 in these samples. Then we measured these mediators by using immunoenzymatic methods.. IL-8 levels were highly increased in patients with severe asthma ( P < .0001), and leukotriene B 4 levels were significantly increased in patients with severe asthma and patients with chronic obstructive pulmonary disease. Lipoxin A 4 was significantly increased in the supernatant obtained from patients with mild asthma ( P < .0001), whereas 15-epi-lipoxin A 4 levels were higher in patients with severe asthma ( P = .05). More interestingly, we found a positive correlation between the level of lipoxin A 4 and IL-8 in patients with mild asthma.. These results indicate that induced sputum is a suitable method to assess lipoxin and 15-epi-lipoxin measurements in bronchi. The mechanisms involved in the synthesis of these 2 eicosanoid mediators would be helpful to understand better the imbalance between proinflammatory and anti-inflammatory mediators occurring in severe asthma. Lipoxin production involves interaction between lipoxygenases, whereas 15-epi-lipoxin production might involve CytP450 activity.

Topics: Adult; Asthma; Female; Humans; Interleukin-8; Leukotriene B4; Lipoxins; Male; Middle Aged; Pneumonia; Pulmonary Disease, Chronic Obstructive; Sputum

To evaluate the role of Chlamydia pneumoniae respiratory tract infection on pediatric asthma, allergic rhinitis or atopic eczema initiation, children of three age groups (n=1211) were prospectively studied for a C. pneumoniae infection using throat swabs and polymerase chain reaction (PCR) with enzyme immunoassay (EIA) detection. Infected children (study group, SG) were examined monthly until the agent could not be detected, quantifying persistent infection. They were compared with randomly selected, non-infected children without asthma matched for age, gender and origin (control group, CG) regarding lung function and inflammatory parameters as well as initiation of allergic diseases judged by family doctor diagnosis after, in median, 22 months. At the first follow-up examination, SG children revealed a higher leukotriene B4 (median 36 pg/ml vs. 19, p=0.04) and 8-isoprostane (median 15 pg/ml vs. 12, p=0.04) in breath condensate characterizing neutrophil, agent-related inflammation and oxidative stress in the lower airways. Cysteinyl leukotrienes, important in acute allergic inflammation, were without difference. Local, anti C. pneumoniae secretory immunoglobulin A antibodies were higher in children after C. pneumoniae infection (optical density median 0.7 vs. 0.4, p=0.001) confirming PCR-EIA results. At the final examination, there was no difference in pathological lung function tests, parameters of exhaled breath condensate or eosinophilia of the nasal mucosa. Incidence of asthma (0/55 vs. 5/54, p=0.03) and allergic rhinitis [3/53 vs. 10/52, p=0.04, odds ratio and 95% confidence interval-OR 0.25 (0.06;0.98)] as well as prevalence of asthma [1/56 vs. 9/58, p=0.02, OR 0.1 (0.01;0.81)] and allergic rhinitis [6/56 vs. 16/58, p=0.03, OR 0.32 (0.11;0.88)] were lower in the SG children. There was no association in atopic eczema. Three children with persistent infection revealed a slightly higher incidence in allergic rhinitis without significance than those with single C. pneumoniae detection (1/3 vs. 2/50), however, not to the CG. In conclusion a C. pneumoniae upper respiratory tract infection may be regarded as a protective factor for childhood asthma or allergic rhinitis in a population of kindergarten and school-age children.

Topics: Adolescent; Animals; Asthma; Child; Child, Preschool; Chlamydophila Infections; Chlamydophila pneumoniae; Cohort Studies; Dermatitis, Atopic; Dinoprost; Female; Humans; Immunoenzyme Techniques; Immunoglobulin A; Leukotriene B4; Male; Pneumonia, Bacterial; Polymerase Chain Reaction; Respiratory Function Tests; Rhinitis

Topics: Asthma; Breath Tests; Cross-Sectional Studies; Humans; Leukotriene B4; Prospective Studies; Pulmonary Disease, Chronic Obstructive; Sputum

Some patients with COPD present with significant reversibility of airflow limitation after receiving bronchodilation therapy. Leukotriene B(4) (LTB(4)) has been implicated in the pathophysiology of both COPD and asthma. We tested the hypothesis that COPD patients with airflow reversibility and asthmatic patients who smoke might have similar levels of LTB(4) in exhaled breath condensate (EBC) and sputum supernatant. The repeatability and stability of LTB(4) measurements were additionally studied.. Prospective, cross-sectional study.. We studied 30 patients with COPD (15 smokers [FEV(1), 56% predicted; SD, 6% predicted]; 15 patients with significant reversibility in airway obstruction after bronchodilation [FEV(1), 14% predicted; SD, 2% predicted]). Fifteen asthmatic patients who smoked, with similar FEV(1) and reversibility were also studied. Ten healthy smokers served as control subjects.. A hospital research laboratory.. Spirometry and reversibility testing were performed on the first visit. On the following day, EBC was collected for the measurement of LTB(4), and induced sputum was collected for differential cell counts and LTB(4) measurement in the sputum supernatant.. LTB(4) levels in EBC [mean (SD)] were increased in COPD patients (mean, 86.7 pg/mL; SD, 19 pg/mL) and asthmatic patients (mean, 97.5 pg/mL; SD, 15 pg/mL) compared to control subjects (mean, 32.3 pg/mL; SD, 10 pg/mL; p < 0.0001 for both groups). COPD patients with airflow reversibility (mean, 99.8 pg/mL; SD, 12 pg/mL) had values similar to those of asthmatic patients (mean, 97.5 pg/mL; SD, 15 pg/mL; p = 0.2) and higher than those of COPD patients without airflow reversibility (mean, 73.7 pg/mL; SD, 17 pg/mL; p = 0.002). Similar results were observed in the sputum supernatant. Measurements of LTB(4) in EBC and sputum were repeatable on two consecutive days, but measurements in the frozen samples of EBC and sputum were not stable after 3 weeks.. Patients with asthma and reversible COPD presented with higher LTB(4) values compared to patients with nonreversible COPD and healthy smokers. This difference may be mainly attributed to the presence of reversibility in airway obstruction, probably as part of a common underlying inflammatory process.

Topics: Adult; Aged; Asthma; Breath Tests; Cross-Sectional Studies; Diagnosis, Differential; Humans; Leukotriene B4; Male; Middle Aged; Prospective Studies; Pulmonary Disease, Chronic Obstructive; Sputum

Recent studies have repeatedly shown weak correlations among lung function parameters, atopy, exhaled nitric oxide level (Feno), and airway inflammatory markers, suggesting that they are non-overlapping characteristics of asthma in adults. A study was undertaken to determine, using factor analysis, whether the above features represent separate dimensions of childhood asthma.. Clinically stable asthmatic patients aged 7-18 years underwent spirometric testing, methacholine bronchial challenge, blood sampling for atopy markers and chemokine levels (macrophage derived chemokine (MDC), thymus and activation regulated chemokine (TARC), and eotaxin), Feno, and chemokines (MDC and eotaxin) and leukotriene B(4) measurements in exhaled breath condensate (EBC).. The mean (SD) forced expiratory volume in 1 second (FEV1) and Feno of 92 patients were 92.1 (15.9)% predicted and 87.3 (65.7) ppb, respectively. 59% of patients received inhaled corticosteroids. Factor analysis selected four different factors, explaining 55.5% of total variance. The Kaiser-Meyer-Olkin measure of sampling adequacy was 0.587. Plasma total and specific IgE levels, peripheral blood eosinophil percentage, and Feno loaded on factor 1; plasma TARC and MDC concentrations on factor 2; MDC, eotaxin and leukotriene B4 concentrations in EBC on factor 3; and plasma eotaxin concentration together with clinical indices including body mass index and disease severity score loaded on factor 4. Post hoc factor analyses revealed similar results when outliers were excluded.. The results suggest that atopy related indices and airway inflammation are separate dimensions in the assessment of childhood asthma, and inflammatory markers in peripheral blood and EBC are non-overlapping factors of asthma.

Topics: Administration, Inhalation; Adolescent; Adrenal Cortex Hormones; Asthma; Biomarkers; Bronchitis; Chemokines; Child; Chronic Disease; Factor Analysis, Statistical; Forced Expiratory Volume; Humans; Hypersensitivity, Immediate; Leukotriene B4; Nitric Oxide; Vital Capacity

Late-phase airway hyperresponsiveness (AHR) in asthma is considered the event leading to persistent inflammation in the lungs, but the molecular mechanisms involved in this process are poorly understood.. To examine the role of TNF-alpha in the development of a late AHR and airway inflammation in asthma.. We established a murine model of asthma with not only biphasic AHR to methacholine but also airway eosinophilia. The effect of TNF-alpha blockade was determined by using anti-TNF-alpha antibody and TNF-alpha knockout mice. Cytosolic phospholipase A(2) (cPLA(2)) mRNA expression and activity were assessed by using RT-PCR and 1-stearoyl-2-[1-(14)C] arachidonyl-sn-glycero-3-phosphocholine as the substrate, respectively.. TNF-alpha blockade resulted in significant inhibition of the late AHR without affecting the early AHR, and reduction in airway eosinophilia and inflammation. cPLA(2) activity was increased in asthmatic lungs in a TNF-alpha-dependent way, and cPLA(2) inhibitor blocked late AHR and airway eosinophilia. TNF-alpha also stimulated the synthesis of cPLA(2) metabolites such as leukotriene B(4) and platelet-activating factor in the airway. Specific inhibitors of cPLA(2) metabolites inhibited the late AHR and airway eosinophilia.. TNF-alpha is the proximal key cytokine capable of developing late-phase AHR and subsequent airway inflammation through expression/activation of cPLA(2).

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Bronchoconstrictor Agents; Cytosol; Disease Models, Animal; Enzyme Activation; Histamine; Inflammation; Leukotriene B4; Male; Methacholine Chloride; Mice; Mice, Inbred BALB C; Mice, Knockout; Phospholipases A; Platelet Activating Factor; Pulmonary Eosinophilia; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Necrosis Factor-alpha

Bronchial asthma is an increasingly common disorder that remains poorly understood and difficult to manage. The disease is characterized by airway hyperresponsiveness, chronic inflammation, and mucus overproduction. Based on the finding that leukotriene B4 receptor 1 (BLT1) is expressed highly in Th2 lymphocytes, we analyzed the roles of BLT1 using an OVA-induced bronchial asthma model. BLT1-null mice did not develop airway hyperresponsiveness, eosinophilic inflammation, and hyperplasia of goblet cells. Attenuated symptoms were accompanied by reduced IgE production, and accumulation of IL-5 and IL-13 in bronchoalveolar lavage fluid, suggesting attenuated Th2-type immune response in BLT1-null mice. Peribronchial lymph node cells of sensitized BLT1-null mice showed much attenuated proliferation and production of Th2 cytokines upon re-stimulation with Ag in vitro. Thus, LTB4-BLT1 axis is required for the development of Th2-type immune response, and blockade of LTB4 functions through BLT1 would be novel and useful in the effort to ameliorate bronchial asthma and related Th2-biased immune disorders.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Calcium; Disease Models, Animal; Immunity, Innate; Immunoglobulin E; Leukotriene B4; Lung; Mice; Mice, Knockout; Peroxidase; Receptors, Leukotriene B4; Respiratory System; Th2 Cells

Smoking is the most important cause of chronic obstructive pulmonary disease (COPD). However, the influence of cigarette smoking on the pathogenesis of asthma in the elderly remains controversial. This study attempted to clarify the influence of cigarette smoking on elderly asthmatics.. Forty-eight asthmatics over 70 years old (25 ex-smokers and 23 never-smokers) and 20 patients with COPD over 70 years old (all ex-smokers) were studied to determine the influence of cigarette smoking on IgE-mediated allergy (total IgE, IgE antibodies against inhalant allergens, bronchial hyper-responsiveness (BHR), generation of leukotriene (LT) B4 and C4), pulmonary function, and the relative area of lung showing attenuation values less than -950 Hounsfield units (RA950) on high-resolution computed tomography scans.. The incidence of positive IgE antibodies against inhalant allergens, BHR, and the generation of leukotriene B4 (LTB4) by leucocytes were significantly increased in patients with a history of smoking compared with those without. Residual volume (%RV) was significantly increased, and diffusing capacity for carbon monoxide was significantly decreased in ex-smokers with asthma and COPD compared with never-smokers with asthma. Inspiratory RA950 and ratio of expiratory RA950 to inspiratory RA950 were significantly larger in asthmatics with a smoking history than in those without, and in COPD patients than in asthmatics.. Cigarette smoking enhances the production of IgE antibodies, BHR, and generation of LTB4 by leucocytes in elderly asthmatics. Increased hyper-inflation or emphysematous changes of the lungs expressed by increased RA950, closely related to %RV, was more frequently observed in ex-smokers compared with never-smokers.

Topics: Aged; Asthma; Bronchial Hyperreactivity; Case-Control Studies; Chi-Square Distribution; Female; Humans; Immunoglobulin E; Leukocytes; Leukotriene B4; Leukotriene C4; Male; Pulmonary Diffusing Capacity; Pulmonary Disease, Chronic Obstructive; Respiratory Function Tests; Smoking; Tomography, X-Ray Computed

Cysteinyl leukotrienes (cys-LTs), LTB4 and 8-isoprostane are increased in the exhaled breath condensate (EBC) from asthmatic patients. The aim of this study was to investigate whether the measurement of cys-LTs, LTB4 and 8-isoprostane in EBC can reflect the level of airway inflammation assessed by induced sputum in asthmatic children sensitized to house dust mite (HDM) during natural avoidance of HDM allergens. Twelve children were evaluated at the time of admission (T0) and after 3 months of stay (T1) at the Istituto Pio XII (Misurina, Italian Dolomites 1756 m). Sputum eosinophil percentage and measurement of cys-LTs, LTB4 and 8-isoprostanes in the breath condensate at T0 and T1 were evaluated. Eosinophil percentage in induced sputum was 8.5 +/- 1.1% at T0 and 3.5 +/- 0.4% at T1 (p = 0.011). Neutrophil percentage in sputum was 1.1 +/- 0.5% at T0 and 1.5 +/- 1.0% at T1 (ns). Cys-LTs mean level was 14.24 +/- 4.53 pg/ml at T0 and 4.65 +/- 0.68 pg/ml at T1 (p = 0.0125). LTB4 level was 2.36 +/- 0.19 pg/ml at T0 and 2.41 +/- 0.23 pg/ml at T1 (ns). 8-Isoprostane level reduced from 17.47 +/- 3.18 pg/ml at T0 to 7.36 +/- 3.26 pg/ml at T1 (p = 0.003). This study show that exhaled cys-LTs and 8-isoprostane, as well as eosinophil percentage in induced sputum, are reduced after allergen avoidance in asthmatic children suggesting a potential application of EBC for the non-invasive evaluation of airway inflammation in asthma in allergic asthmatic children.

Topics: Adolescent; Altitude; Asthma; Breath Tests; Child; Cysteine; Eicosanoids; Eosinophils; Female; Humans; Leukotriene B4; Leukotrienes; Male; Pilot Projects; Prostaglandins A; Pyroglyphidae; Sputum

The noninvasive assessment and monitoring of airway inflammation could be important in respiratory disease. The pH of exhaled breath condensate (EBC) is a promising marker. Although pH has been measured in the EBC of adults with inflammatory airway diseases, no study has measured this in children.. This study aimed to assess whether there is a change in pH in the EBC of children with cystic fibrosis (CF) and asthma, and to try to determine whether pH could be used as a marker of airway inflammation. Furthermore, the relationships among EBC pH, severity of disease, and oxidative stress were studied.. We studied 20 children with CF (mean [+/- SEM] age, 7 +/- 3 years), 20 children with asthma (mean age, 7 +/- 2 years), and 15 age-matched healthy children (mean age, 7 +/- 2 years). The pH of EBC was measured using a pH meter.. Lower pH values were observed in the EBC of children with CF and asthma compared to control subjects (mean pH, 7.23 +/- 0.03 and 7.42 +/- 0.01 vs 7.85 +/- 0.02, respectively). Furthermore, relationships among EBC pH, severity of asthma, and the presence of an infective exacerbation of CF was found. There was a negative correlation between exhaled pH and exhaled leukotriene B(4) concentrations (r = -0.5; p < 0.005).. We conclude that the measurement of EBC pH may be useful in the evaluation of airway inflammation in children with asthma and CF.

Topics: Asthma; Breath Tests; Case-Control Studies; Child; Child, Preschool; Cystic Fibrosis; F2-Isoprostanes; Female; Humans; Hydrogen-Ion Concentration; Inflammation Mediators; Leukotriene B4; Male; Predictive Value of Tests; Probability; Prognosis; Prospective Studies; Reference Values; Respiratory Function Tests; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Statistics, Nonparametric

Aspirin challenge of aspirin-intolerant asthma (AIA) patients causes a significant increase in leukotriene E4 (LTE4) concentration in urine. However, knowledge on leukotriene B4 (LTB4) generation in patients with AIA is insufficient. Recent research has demonstrated that exogenously administered LTB4 is excreted as glucuronide into the urine in human healthy subjects.. The purpose of this study is to estimate urinary LTB4 glucuronide (LTBG) concentration in the clinically stable condition in healthy subjects and asthmatic patients and to investigate changes in urinary LTBG concentration in patients with AIA after aspirin challenge.. A provocation test was performed by intravenous aspirin challenge. After urine was hydrolysed by beta-glucuronidase, the fraction containing LTB4 was purified by high-performance liquid chromatography and LTB4 concentration was quantified by enzyme immunoassay. Urinary LTBG concentration was calculated as the difference between the concentration obtained with hydrolysis and that without hydrolysis.. (1) After hydrolysis, the presence of urinary LTB4 was verified by gas chromatography-mass spectrometry-selected ion monitoring. (2) The urinary LTBG concentration was significantly higher in the asthmatic patients than in the healthy subjects (median, 5.37 pg/mg creatinine [range 1.2-13] vs. 3.32 pg/mg creatinine [range, 0.14-10.5], P = 0.0159). (3) The patients with AIA (n = 7), but not those with aspirin-tolerant asthma (n = 6), showed significant increases in LTBG and LTE4 excretions after aspirin challenge. (4) When the concentrations after aspirin challenge were analysed simultaneously, a significant linear correlation was observed between urinary LTBG concentration and urinary LTE4 concentration in patients with AIA (Spearman's rank correlation test, r = 0.817, P = 0.0003).. LTBG is present in human urine, albeit at a concentration lower than urinary LTE4. In addition to a marked increase in cysteinyl-leukotriene production, aspirin challenge induced LTB4 production in AIA patients.

Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Asthma; Case-Control Studies; Female; Glucuronides; Humans; Leukotriene B4; Leukotriene E4; Male; Middle Aged; Statistics, Nonparametric

Epidemiologic studies suggest increased asthma prevalence in obese subjects. However, the relation between obesity and airway inflammation remains unclear. This cross-sectional study aims to investigate the relation between obesity indices and exhaled nitric oxide (ENO) and leukotriene B(4) (LTB(4)) in children with asthma. Asthmatic patients aged 7-18 yr old were recruited. Weight-for-height Z score was calculated from anthropometry. ENO was measured by online single-breath method using a chemiluminescence analyzer, whereas LTB(4) concentrations in exhaled breath condensate (EBC) were quantified using competitive enzyme immunoassay. Ninety-two asthmatics and 23 controls were recruited. The mean ENO and LTB(4) concentrations in EBC were higher in asthmatic patients (87 p.p.b. and 40.5 pg/ml) than controls (25 p.p.b. and 18.7 pg/ml) (p < 0.0001 for both). Obesity, as defined by weight >120% median weight-for-height, was not associated with any alteration in ENO or LTB(4) concentrations in patients with asthma. Besides, these inflammatory markers did not differ between asthmatics in the highest and lowest quartiles of weight-for-height Z score. On multivariate analysis, ENO showed significant correlation with age (beta = 0.511, p < 0.0001), peripheral blood eosinophil count (beta = 0.222, p = 0.019), plasma total IgE concentration (beta = 0.187, p = 0.050) and forced expiratory volume in 1-s (FEV(1); beta = -0.221, p = 0.014). None of the factors was associated with LTB(4) concentration in EBC. In conclusion, ENO and LTB(4) concentration in EBC are increased in childhood asthma. However, these inflammatory markers did not differ between obese and non-obese children with asthma.

Topics: Adolescent; Asthma; Breath Tests; Child; Cross-Sectional Studies; Female; Humans; Inflammation; Leukotriene B4; Lung; Male; Nitric Oxide; Obesity; Respiratory Function Tests

5-Lipoxygenase is the key enzyme in the biosynthesis of leukotrienes, powerful lipid mediators involved in inflammation, cell-cell communication, and other important physiological and pathological conditions. Particularly, cysteinyl-leukotrienes have been recognized as playing a significant role in the pathophysiology of asthma and potent and effective Cys-LT1 receptor antagonists have been developed for the treatment of this illness. Here we report that montelukast, a structural Cys-LT1 receptor antagonist, also exerts a substantial and apparently direct inhibitory effect on 5-lipoxygenase activity in vitro, at concentrations in the lower micromolar range, which are of potential therapeutic relevance. Thus, when human mast cells HMC-1 were stimulated with the Ca ionophore A23187 in the presence of montelukast (up to 100 microM) a substantial decline in 5-lipoxygenase biosynthesis was observed. Similar results were obtained in the rat mast cell-like RBL-1 cell model (IC50 congruent with 2.5 microM) and in human polymorphonuclear leukocytes. Moreover, montelukast directly inhibited human recombinant 5-lipoxygenase. Kinetic experiments revealed that the inhibition was of the non-competitive type, suggesting that montelukast binds a yet undefined allosteric site on 5-lipoxygenase. 5-Lipoxygenase inhibition by montelukast appears to be highly selective since the drug had no effects on other enzymes of the leukotriene cascade, viz. LTC4 synthase and LTA hydrolase.

Topics: Acetates; Allosteric Site; Animals; Anti-Asthmatic Agents; Asthma; Calcimycin; Calcium; Catalysis; Cell Line; Cell Line, Tumor; Cell Survival; Cells, Cultured; Chromatography, High Pressure Liquid; Cyclopropanes; Dexamethasone; Dose-Response Relationship, Drug; HL-60 Cells; Humans; Inhibitory Concentration 50; Kinetics; Leukotriene B4; Leukotriene C4; Lipoxygenase Inhibitors; Mast Cells; Neutrophils; Protein Binding; Quinolines; Rats; Recombinant Proteins; Sulfides

The objective of this study is the measurement of leukotriene B7 (LTB4), a potent inflammatory mediator, in exhaled breath condensate by using liquid chromatography/mass spectrometry (LC/MS and LC/MS/MS). Condensation of exhaled breath is a non-invasive method to collect airway secretions. Deuterated (d4)-LTB4 was used as internal standard. The MS and MS/MS behavior of LTB4 and LTB4-d4 was studied by electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) in both positive and negative ion polarity mode. Preliminary results show that monitoring negative ions in ESI mode has the best sensitivity for both LTB4 and LTB4-d4. Therefore, negative ESI was chosen, and the [M-H]- ions at m/z 335 and 339 were selected for quantification. The lower limit of quantification for LTB4, expressed as the lowest point of the calibration curve, was 100 pg/mL. Using this technique, we measured LTB4 in exhaled breath condensate in two healthy subjects, four asthmatic patients on anti-inflammatory treatment, and four asthmatic patients who were not on anti-inflammatory drugs. Exhaled LTB4 concentrations were detected only in asthmatic patients who were not on anti-inflammatory therapy. This method is potentially useful for non-invasive assessment of airway inflammation, but the sensitivity of the technique needs to be improved.

Topics: Adolescent; Adult; Asthma; Atmospheric Pressure; Breath Tests; Child; Chromatography, High Pressure Liquid; Exhalation; Female; Humans; Leukotriene B4; Male; Spectrometry, Mass, Electrospray Ionization

Leukotriene B4 (LTB4) was originally described as a potent lipid myeloid cell chemoattractant, rapidly generated from innate immune cells, that activates leukocytes through the G protein-coupled receptor BLT1. We report here that BLT1 is expressed on effector CD4+ T cells generated in vitro as well as in vivo when effector T cells migrate out of the lymphoid compartment and are recruited into peripheral tissues. BLT1 mediated LTB4-induced T helper type 1 (T(H)1) and T(H)2 cell chemotaxis and firm adhesion to endothelial cells under flow, as well as early CD4+ and CD8+ T cell recruitment into the airway in an asthma model. Our findings show that the LTB4-BLT1 pathway is involved in linking early immune system activation and early effector T cell recruitment.

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; CD4-Positive T-Lymphocytes; Chemotaxis, Leukocyte; Disease Models, Animal; Female; Flow Cytometry; Immunoglobulin E; Immunoglobulin G; Leukotriene B4; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptors, Leukotriene B4; T-Lymphocyte Subsets

To investigate antigen-induced changes of leukotriene B(4)(LTB(4))content and LTA(4)-hydrolase mRNA expression in lung tissue and cerebral cortex in sensitized rats.. The contents of LTB(4) in lung tissue and cerebral cortex homogenates and LTA(4)-hydrolase mRNA expression after antigen challenge by aerosol were respectively detected by reverse-phase high performance liquid chromatography(RP-HPLC) and semi-quantitative RT-PCR.. The LTB(4) levels in lung tissue and cerebral cortex homogenates in asthmatic rats were significantly higher than those in control (P%0.05), and LTA4-hydrolase mRNA expression was also increased in asthmatic group. Dexamethason(DXM, 0.5 mg/kg, i.p.) decreased the LTB(4) content and inhibited the LTA(4)-hydrolase mRNA expression significantly in asthmatic rats(P%0.05).. LTB(4) content and LTA(4)-hydrolase mRNA expression in cerebral cortex and lung tissue are increased in asthmatic rats, and there may exist neuroimmunological cross-talking between central nervous system and lung tissue in asthma.

Topics: Animals; Asthma; Cerebral Cortex; Epoxide Hydrolases; Female; Leukotriene B4; Lung; Male; Rats; Rats, Sprague-Dawley; RNA, Messenger

To explore the changes of leukotrienes (LT) in cerebral cortex and lung tissues in ovalbumin-induced rat asthma model and effects of different anti-asthma drugs on the changes.. Aerosol antigen-induced changes of inflammation in bronchoalveolar lavage fluids (BALF), pulmonary and brain histologic section in sensitized rats were investigated. Changes of LTB4 and LTC4 in lung and cerebral cortex homogenates were analyzed by reverse-phase high performance liquid chromatography (RP-HPLC).. The number of inflammatory cells in BALF and the score of lung and brain histological examination from antigen- challenged rats were significantly higher than that from control group (P<0.05). Dexamethason (DXM, 0.5 mg/kg, ip) and ketotifen fumarate (KF, 5 mg/kg, ig) markedly reduced total leukocyte number in BALF, and inhibited eosinophil accumulation, reduced the infiltration of eosinophils, and improved mucous edema and epithelial lesion of bronchi and bronchioles. In addition, RP-HPLC results shown LTB4 in lung and cerebral cortex homogenates were increased in antigen-challenged rats [(4.1+/-2.4) ng/g and (1.5+/-0.9) ng/g, respectively] compared with control group [(1.55+/-0.21) ng/g and (0.7+/-0.3) ng/g, respectively, P<0.05], both DXM (0.5 mg/kg, ip) and KF (5 mg/kg, ig) reduced LTB4 amount in lung[(1.4+/-0.6) ng/g and (1.8+/-0.7) ng/g] and cerebral cortex homogenates [(0.5+/-0.4) ng/g and (0.7+/-0.4) ng/g] in asthma rats. LTC4 content in lung homogenates in asthma rats was increased compared with control group [(1.9+/-0.9) ng/g and (0.5+/-0.3) ng/g, respectively] (P<0.05), but it has no change in cerebral cortex homogenates. DXM (0.5 mg/kg, ip) and KF (5 mg/kg, ig) reduced LTC4 amount in lung homogenates in asthma rats [(0.8+/-0.6) ng/g and (1.0+/-0.3) ng/g, respectively] (P<0.05).. The results indicate there is coincidental increase of LTB4 between central nervous system and lung tissues in asthma rats. DXM and KF can inhibit the change.

Topics: Animals; Anti-Inflammatory Agents; Asthma; Cerebral Cortex; Dexamethasone; Female; Histamine H1 Antagonists; Ketotifen; Leukotriene B4; Leukotriene C4; Lung; Male; Ovalbumin; Rats; Rats, Sprague-Dawley

The pathogenesis of aspirin-induced asthma (AIA) has not yet been clearly elucidated, although eicosanoid metabolites appear to play an important role. We hypothesized that levels of eicosanoids in exhaled air condensate are abnormal in patients with AIA and that they change in patients receiving steroid therapy. We measured cysteinyl-leukotrienes (cys-LTs), prostaglandin E(2) (PGE(2)), and leukotriene B(4) (LTB(4)), and also 8-isoprostane as a marker of oxidative stress, by enzyme immunoassay in exhaled breath condensate from patients with AIA (17 steroid naive; mean age, 41 +/- 23 years; FEV(1), 63%pred), 26 patients with aspirin-tolerant asthma (ATA) (11 steroid naive; mean age, 47 +/- 18 years; FEV(1), 69%pred), and 16 healthy subjects (mean age, 45 +/- 17 years; FEV(1), 93%pred). Cys-LTs were significantly higher in steroid-naive patients with AIA compared with steroid-naive patients with ATA and healthy subjects (152.3 +/- 30.4 and 36.6 +/- 7.1 versus 19.4 +/- 2.8 pg/ml; p < 0.05 and p < 0.05, respectively). Steroid-naive patients with AIA also had higher levels of 8-isoprostane than normal subjects (131.8 +/- 31.0 versus 21.9 +/- 4.5 pg/ml; p < 0.05). There were significantly lower levels of both cys-LTs and 8-isoprostanes in steroid-treated patients with AIA. There was no difference in either the PGE(2) or LTB(4) level between the patient groups. This is the first study to show that cys-LTs and 8-isoprostanes are elevated in expired breath condensate of steroid-naive patients with AIA, and that cys-LTs are decreased in steroid-treated patients. Exhaled PGE(2) levels are not reduced, so that it is unlikely that a deficiency of PGE(2) is an important mechanism, whereas exhaled LTB(4) levels are unchanged, indicating an abnormality beyond 5-lipoxygenase.

Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Asthma; Breath Tests; Cysteine; Dinoprost; Dinoprostone; F2-Isoprostanes; Female; Humans; Inflammation Mediators; Leukotriene B4; Leukotrienes; Male; Middle Aged; Oxidative Stress; Oxytocics; Respiratory System; Vasoconstrictor Agents

Cysteinyl leukotrienes (cys-LTs; LTC4, LTD4, and LTE4) are generated predominantly by mast cells and eosinophils and induce airway smooth muscle contraction, microvascular leakage, and mucous hypersecretion whereas leukotriene B4 (LTB4) is a potent chemoattractant of neutrophils. We measured cys-LTs and LTB4 in exhaled breath condensate from children aged 7-14 years including healthy nonatopic children (n = 11) and children with mild intermittent asthma (steroid naive, n = 11), mild persistent asthma (low-dose inhaled steroid treatment, n = 13), or moderate to severe persistent asthma (high-dose inhaled steroid treatment, n = 13). Exhaled LTB4 levels were increased in patients with mild and moderate to severe persistent asthma compared with patients with mild intermittent asthma (126.0 +/- 8.8 and 131.9 +/- 7.1 versus 52.7 +/- 3.8 pg/ml, p < 0.001 and p < 0.0001) and normal subjects (126.0 +/- 8.8 and 131.9 +/- 7.1 versus 47.9 +/- 4.1 pg/ml, p < 0.0001). Elevated exhaled cys-LT levels were found in patients with mild and moderate to severe persistent asthma compared with normal subjects (27.9 +/- 2.8 and 31.5 +/- 4.5 versus 18.5 +/- 0.5 pg/ml, p < 0.01 and p < 0.05). There was an inverse correlation between exhaled cys-LTs and LTB4 in patients with mild persistent asthma. We conclude that exhaled cys-LTs and LTB4 may be noninvasive markers of airway inflammation in pediatric asthma.

Topics: Adolescent; Asthma; Biomarkers; Breath Tests; Child; Child Welfare; Cysteine; Female; Forced Expiratory Volume; Humans; Leukotriene B4; Leukotrienes; Male; Nitric Oxide; Respiration; Severity of Illness Index; Statistics as Topic; Steroids, Fluorinated; Treatment Outcome; United Kingdom

Most of the studies investigating the role of leukotrienes (LTs) and prostaglandins (PGs) in asthma have used invasive (eg, bronchoalveolar lavage fluid) or semi-invasive (eg, sputum induction) techniques. Others have measured eicosanoids in plasma or urine, probably reflecting systemic rather than lung inflammation. Collection of exhaled breath condensate (EBC) is a noninvasive method to collect airway secretions.. We sought to investigate whether eicosanoids are measurable in EBC, to show possible differences in their concentrations in asthmatic patients and healthy subjects, and to investigate whether exhaled eicosanoids correlate with exhaled nitric oxide (NO), a marker of airway inflammation.. Twelve healthy nonsmokers and 15 steroid-naive patients with mild asthma were studied. Subjects attended on one occasion for pulmonary function tests, collection of EBC, and exhaled NO measurements. Exhaled LTB(4)-like immunoreactivity, LTE(4)-like immunoreactivity, PGE(2)-like immunoreactivity, PGD(2)-methoxime, PGF(2)(alpha)-like immunoreactivity, and thromboxane B(2)-like immunoreactivity were measured by means of enzyme immunoassays.. LTE(4)-like immunoreactivity and LTB(4)-like immunoreactivity were detectable in EBC in healthy subjects, and their levels in asthmatic patients were increased about 3-fold (P <.0001) and 2-fold (P <.0005), respectively. Exhaled NO was increased in asthmatic patients compared with healthy subjects (P <.0001). There was a correlation between exhaled LTB(4) and exhaled NO (r = 0.56, P <.04) in patients with asthma. When measurable, prostanoid levels were similar in asthmatic patients and control subjects.. Exhaled LTE(4) and LTB(4) are increased in steroid-naive patients with mild asthma. EBC may be proved to be a novel method to monitor airway inflammation in asthma.

Topics: Adult; Asthma; Breath Tests; Cross-Sectional Studies; Female; Humans; Leukotriene B4; Leukotriene E4; Lung; Male; Nitric Oxide; Prostaglandins

Despite advances in understanding the pathophysiology of asthma, morbidity and mortality in pediatrics continue to rise. Little is known about the initiation and chronicity of inflammation resulting in asthma in this young population. We evaluated 20 "wheezing" children (WC) (median age 14.9 mo) with a minimum of two episodes of wheezing or prolonged wheezing > or = 2 mo in a 6-mo period with bronchoscopy and bronchoalveolar lavage (BAL). Comparisons were made with six normal controls (NC) (median age 23.3 mo) undergoing general anesthesia for elective surgery. BAL fluid cell counts and differentials were determined. The eicosanoids, leukotriene (LT) B(4), LTE(4), prostaglandin (PG)E(2), and 15-hydroxyeicosatetraenoic acid (HETE) and the mast cell mediators, beta-tryptase and PGD(2), were evaluated by enzyme immunoassay (EIA). WC had significant elevations in total BAL cells/ml (p = 0.01), as well as, lymphocytes (LYMPH, p = 0.007), macrophages/monocytes (M&M, p = 0.02), polymorphonuclear cells (PMN, p = 0.02), epithelial cells (EPI, p = 0.03), and eosinophils (EOS, p = 0.04) compared with NC. Levels of PGE(2) (p = 0.0005), 15-HETE (p = 0.002), LTE(4) (p = 0.04), and LTB(4) (p = 0.05) were also increased in WC compared with NC, whereas PGD(2) and beta-tryptase were not. This study confirms that inflammation is present in the airways of very young WC and may differ from patterns seen in adults with asthma.

Topics: Age Factors; Asthma; Bronchoalveolar Lavage Fluid; Bronchoscopy; Case-Control Studies; Chronic Disease; Dinoprostone; Disease Progression; Female; Humans; Hydroxyeicosatetraenoic Acids; Infant; Inflammation; Inflammation Mediators; Leukocyte Count; Leukotriene B4; Male; Prostaglandin D2; Respiratory Sounds; Risk Factors; Serine Endopeptidases; Tryptases

Carbon monoxide (CO) generated by catalysis of heme by heme oxygenase is increased in the exhaled air of asthmatic patients. Based on recent studies demonstrating that asthma is an inflammatory disease associated with increased oxidants and that CO confers cytoprotection in oxidant-induced lung injury and inflammation, we sought to better understand the functional role of CO in asthma by using an aeroallergen model. Mice were sensitized to ovalbumin, challenged with aerosolized ovalbumin, and maintained in either CO (250 parts/million) or room air for 48 h. The differential effects of CO on bronchoalveolar lavage (BAL) fluid cell types were observed, with a marked attenuation of BAL fluid eosinophils in the CO-treated animals at 24 and 48 h. A marked reduction of the proinflammatory cytokine interleukin-5 was observed in the CO-treated mice, with no significant changes for other proinflammatory cytokines. These differential effects of CO were also observed with leukotrienes (LTs) and prostaglandins in that CO significantly decreased BAL fluid PGE2, and LTB4 but exerted negligible effect on thromboxane B2 or LTC4/D4/E4. Our data suggest a putative immunoregulatory role for CO in aeroallergen-induced inflammation in mice.

Topics: Allergens; Animals; Asthma; Blood Cells; Bone Marrow; Bronchoalveolar Lavage Fluid; Carbon Monoxide; Cytokines; Dinoprostone; Eicosanoids; Eosinophils; Female; Inflammation Mediators; Leukotriene B4; Mice; Mice, Inbred BALB C; Ovalbumin

Leukotriene B(4) (LTB(4)) is a potent chemoattractant and activator of both granulocytes and macrophages. The actions of LTB(4) appear to be mediated by a specific G protein-coupled receptor (GPCR) BLT1, originally termed BLT (Yokomizo, T., T. Izumi, K. Chang, Y. Takuwa, and T. Shimizu. 1997. Nature. 387:620-624). Here, we report the molecular cloning of a novel GPCR for LTB(4), designated BLT2, which binds LTB(4) with a Kd value of 23 nM compared with 1.1 nM for BLT1, but still efficiently transduces intracellular signaling. BLT2 is highly homologous to BLT1, with an amino acid identity of 45.2%, and its open reading frame is located in the promoter region of the BLT1 gene. BLT2 is expressed ubiquitously, in contrast to BLT1, which is expressed predominantly in leukocytes. Chinese hamster ovary cells expressing BLT2 exhibit LTB(4)-induced chemotaxis, calcium mobilization, and pertussis toxin-insensitive inhibition of adenylyl cyclase. Several BLT1 antagonists, including U 75302, failed to inhibit LTB(4) binding to BLT2. Thus, BLT2 is a pharmacologically distinct receptor for LTB(4), and may mediate cellular functions in tissues other than leukocytes. BLT2 provides a novel target for antiinflammatory therapy and promises to expand our knowledge of LTB(4) function. The location of the gene suggests shared transcriptional regulation of these two receptors.

Topics: Amino Acid Sequence; Animals; Arthritis, Rheumatoid; Asthma; Base Sequence; Cell Line; CHO Cells; Cloning, Molecular; Cricetinae; DNA, Complementary; Humans; Inflammatory Bowel Diseases; Leukotriene B4; Mice; Molecular Sequence Data; Psoriasis; Receptors, Leukotriene B4; Renal Insufficiency; Sequence Homology, Amino Acid; Signal Transduction; Tissue Distribution

Topics: Animals; Anti-Asthmatic Agents; Asthma; CD4-Positive T-Lymphocytes; Chemotactic Factors; Cloning, Molecular; HIV Infections; HIV-1; Humans; Leukotriene Antagonists; Leukotriene B4; Ligands; Mice; Molecular Sequence Data; Receptors, Formyl Peptide; Receptors, HIV; Receptors, Immunologic; Receptors, Peptide

The effects of YM158 (3-[(4-tert-butylthiazol-2-yl)methoxy]-5'-[3-(4-chlorobenzenesu lfonyl )propyl]-2'-(1H-tetrazol-5-ylmethoxy)benzanilide monosodium salt monohydrate), a new dual antagonist for leukotriene D(4) and thromboxane A(2) receptors, on antigen-induced increases in airway resistance were investigated in mediator-controlled novel asthmatic models using actively sensitized guinea pigs. While the predominant mediator was thromboxane A(2), complete inhibition of cyclooxygenase induced mediation by cysteinyl-leukotrienes. About 1-mg/kg indomethacin induced a state where both mediators participated equally. YM158 inhibited increases in resistance whether only one or both mediators were involved. When leukotriene D(4) and thromboxane A(2) equally participated, ED(50) values for 4-oxo-8-[4-(4-phenylbutoxy)benzoylamino]-2-(tetrazol-5-yl)-4 H-1-benzo pyran hemihydrate (pranlukast; 3.9 mg/kg) and 7-(3,5,6-trimethyl-1, 4-benzoquinon-2-yl)-7-phenylheptanoic acid (seratrodast; 2.1 mg/kg) were similar to that for YM158 (8.3 mg/kg), although those effects on the corresponding mediator-induced reaction were 10 times stronger than those of YM158. Additionally, the maximum inhibition of YM158 was stronger than those of either single receptor antagonist. In conclusion, YM158 has a potentially greater efficacy in wider types of experimental asthmatic models than single receptor antagonists.

Topics: Administration, Oral; Airway Resistance; Animals; Anti-Asthmatic Agents; Anti-Inflammatory Agents, Non-Steroidal; Antigens; Asthma; Benzoquinones; Chromones; Dose-Response Relationship, Drug; Guinea Pigs; Heptanoic Acids; Indomethacin; Leukotriene Antagonists; Leukotriene B4; Leukotriene C4; Leukotriene E4; Lipid Metabolism; Lung; Male; Membrane Proteins; Ovalbumin; Receptors, Leukotriene; Receptors, Thromboxane; Tetrazoles; Thiazoles; Thromboxane B2; Time Factors

Leukotrienes (LTs) are pro-inflammatory mediators that contribute to the pathophysiological features of asthma. The relationship between the amounts of LTB4 and LTC4 produced by the leukocytes of asthmatic patients on the one hand and immunoglobulin E (IgE)-mediated allergy, asthma exacerbations and bronchial hyperresponsiveness was studied. Leukocytes were obtained from peripheral blood drawn from 29 atopic and 27 nonatopic asthmatics during exacerbations and clinically controlled periods, as well as from 20 control individuals. The leukocytes were stimulated with calcium ionophore A23187 to induce LTB4 and LTC4 production. Allergy was assessed by means of specific serum IgE or by positive skin tests, whereas bronchial hyperresponsiveness was measured by methacholine challenge. The leukocytes of the asthmatics generated significantly more LTB4 (p<0.05) and LTC4 (p<0.01) than those of controls. The leukocytes of patients with atopic asthma generated significantly more LTC4 than those of patients with nonatopic asthma (p<0.01). Significantly more LTC4 was produced by leukocytes obtained during exacerbations, than by those obtained during clinically controlled periods (p<0.01). In addition, there was a significant correlation between LTB4 generation by leukocytes and the degree of bronchial hyperresponsiveness to methacholine (r=-0.792, p<0.0001). These results suggest that leukotriene C4 production by leukocytes is associated with immunoglobulin E-mediated allergy and asthma exacerbations, and further that generation of leukotriene B4 is closely related to bronchial hyperresponsiveness in patients with asthma.

Topics: Asthma; Bronchial Hyperreactivity; Female; Humans; Leukocytes; Leukotriene B4; Leukotriene C4; Male; Middle Aged

The aim of this present study was to investigate the effect of amount and degree of oxidation of dietary oil on type 2 T-helper cell (TH)-related immune responses. Four groups of BALB/c mice were fed either 50 g soyabean oil/kg (50-S), 50 g oxidized oil/kg (50-O), 150 g soyabean oil/kg (150-S) or 150 g oxidized oil/kg (150-O). After 14 weeks consuming the experimental diets, the mice were immunized with ovalbumin (OVA) plus Al and antigen-specific immunoglobulin (Ig)E, IgG1 and IgG2a, inflammatory mediators such as prostaglandin (PG) E2 and leukotriene (LT)B4 were determined. Higher hepatic microsomal cytochrome P450 was noted in mice fed 150 g oxidized oil/kg compared with those of other groups. OVA-specific IgG1 and IgE were higher in mice fed 150 g oxidized oil/kg compared with those of the other groups. The data suggested the interleukin (IL)-4: interferon (IFN)-gamma ratio was higher in mice fed 50 g dietary oxidized oil/kg compared with that of the 50-S group. The IL-5:IFN-gamma ratios were higher in the 150-S and 150-O groups than in the 50-S and 50-O groups. PGE2 and LTB4 produced by macrophages stimulated by lipopolysaccharide were highest in mice in the 150 g oxidized oil/kg group. The data suggested that an increased intake of oxidized oil might exert an unfavourable effect on the TH2 response involved in allergic disease.

Topics: Animals; Asthma; Cell Division; Cytokines; Dinoprostone; Energy Intake; Female; Immunoglobulin E; Immunoglobulin G; Inflammation Mediators; Leukotriene B4; Mice; Mice, Inbred BALB C; Ovalbumin; Oxidation-Reduction; Soybean Oil; Spleen; T-Lymphocytes, Helper-Inducer; Weight Gain

The etiology and treatment of premenstrual exacerbations of asthma (PMA) remain uncertain.. We investigated the role of cellular mediators released from inflammatory cells in the airflow limitation during PMA.. Serum levels of leukotriene (LT) B(4), LTC(4), platelet- activating factor, histamine, IL-1beta, IL-4, IL-5, IL-6, and GM-CSF were measured at different time points, first just before or during menstruation when the peak expiratory flow rate (PEFR) began to decrease precipitously and second during the menstrual midcycle week (days 10-16) when the PEFR returned to baseline values in patients with PMA and in age-matched asthma patients without PMA at the same intervals.. Serum levels of LTC(4) were significantly higher during exacerbations of asthma than after recovery (69.0 +/- 16.0 pg/mL vs 24.0 +/- 9.5 pg/mL, P <.05), whereas those of IL-1beta, IL-4, IL-5, IL-6, GM-CSF, histamine, LTB(4), and platelet-activating factor did not differ between 2 periods in 5 patients with PMA. In contrast, in 5 asthmatic patients without PMA serum levels of cellular mediators did not differ between corresponding periods. Oral administration of pranlukast, an LT receptor antagonist (225 mg twice daily), significantly reduced decreases in PEFR from the baseline values (110 +/- 21 L/min with pranlukast vs 233 +/- 20 L/min without pranlukast, P <.01) in association with an improvement of asthma symptom scores (6.5 +/- 1. 1 with pranlukast vs 9.8 +/- 0.7 without pranlukast, P <0.05) in 5 patients with PMA.. LTs are partly involved in the pathogenesis of PMA, and LT receptor antagonists may be useful for preventing airflow obstruction in patients with PMA.

Topics: Adolescent; Adult; Anti-Asthmatic Agents; Asthma; Chromones; Cytokines; Female; Histamine; Humans; Leukotriene Antagonists; Leukotriene B4; Leukotriene C4; Mast Cells; Menstruation; Peak Expiratory Flow Rate; T-Lymphocytes

The formation of leukotriene B4 (LTB4) by neutrophils stimulated with the ionophore A23187 or physiological stimuli in heparinized plasma was investigated. In comparison with neutrophils stimulated (A23187) in a protein-free buffered salt solution, neutrophils stimulated in plasma produced only trace amounts of LTB4. The addition of human recombinant LTA4-hydrolase or erythrocytes to plasma prior to A23187 stimulation strongly and selectively stimulated (> 4-fold) the formation of LTB4 supporting that neutrophils activated in plasma with A23187 release in the extracellular milieu most of LTA4 formed by the cells, and indicating that plasma proteins drastically slow down the further metabolism of LTA4 released by neutrophils. The formation of LTB4 was then investigated in GM-CSF-primed neutrophils stimulated with fMLP in plasma; levels of synthesis were very low and the addition of erythrocytes prior to stimulation strongly enhanced LTB4 synthesis, demonstrating that agonist-stimulated neutrophils also release most of LTA4 generated in the extracellular milieu. Investigations on the fate of LTA4 in plasma revealed that LTA4 was slowly degraded through an unknown process, i.e. not through the previously described non-enzymic hydrolysis resulting in the formation of dihydroxy derivatives of LTA4. Using neutrophils labeled with tritiated arachidonate, we also demonstrated that neutrophils stimulated in plasma with fMLP or A23187, almost exclusively use endogenous arachidonate, as opposed to plasma arachidonate, to generate 5-lipoxygenase products. Finally, experiments performed with purified eosinophils indicated that contrary to neutrophils, the eosinophils do not release LTA4, but directly release LTC4.

Topics: Asthma; Calcimycin; Cell Separation; Eosinophils; Epoxide Hydrolases; Erythrocytes; Granulocytes; Humans; In Vitro Techniques; Leukotriene B4; Neutrophils; Plasma; Pulmonary Eosinophilia; Rhinitis

This study was designed to examine further the role of platelet-activating factor (PAF) in asthma, comparing leukotriene B4 (LTB4) release, 5-lipoxygenase activity and intracellular calcium levels ([Ca2+]i) in macrophages. LTB4 and other lipoxygenase metabolites in macrophages in bronchoalveolar lavage fluids obtained from 23 asthmatic patients and 20 control subjects were measured by reverse-phase high-performance liquid chromatography. [Ca2+]i was monitored using the fluorescent probe fura-2. The basal LTB4 release of resting macrophages was not different between groups (0.02+/-0.01 versus 0.05+/-0.02 ng x 10(-6) cells). When stimulated with calcium ionophore A23187 (2.5 microM), however, macrophages from asthmatic patients released more LTB4 than cells from control subjects (30.2+/-3.4 versus 13.7+/-2.1 ng x 10(-6) cells). Although PAF alone did not alter LTB4 release, it enhanced the response to subsequent A23187 stimulation. This effect was noted following short treatment (i.e., 5 min) at concentrations of > or =1.0 microM PAF, with the maximal effect noted after treatment with 5.0 microM PAF + 2.5 microM A23187 (105.1+/-6.7 versus 15.3+/-2.6 ng x 10(-6) cells). Treatment of macrophages with PAF also increased 5-lipoxygenase activity and [Ca2+]i more in cytosols from asthmatic patients than in cytosols from control subjects. These findings support a role of intracellular calcium in the activation of 5-lipoxygenase which, in turn, augments the release of leukotriene B4. Because levels of platelet-activating factor may be increased in the lung during asthma and can increase the subsequent release of a chemotactic mediator leukotriene B4, from macrophages, these findings suggest that platelet-activating factor may prime the constitutive cells of the lung to augment inflammatory effects important in the pathogenesis of asthma.

Topics: Adult; Arachidonate 5-Lipoxygenase; Asthma; Bronchoalveolar Lavage Fluid; Calcimycin; Calcium; Chromatography, High Pressure Liquid; Cytosol; Female; Humans; Inflammation Mediators; Ionophores; Leukotriene B4; Macrophages, Alveolar; Male; Middle Aged; Osmolar Concentration; Platelet Activating Factor; Reference Values

There are substantial numbers of reports showing that leukotrienes (LTs) play important roles in adult asthma. No definite evidence has been demonstrated that LTs are involved in asthma attacks in children, although it is highly expected. In this report, we demonstrated that the levels of LTB4 and LTC4 but not thromboxane B2 (TXB2), a stable metabolite of TXA2, were significantly elevated in the bronchoalveolar lavage fluid, which was obtained from intubated and mechanically ventilated children with severe asthma attacks. This is direct evidence that LTB4 and LTC4 predominantly participate in asthma attacks in pediatric patients.

Topics: Adolescent; Asthma; Child, Preschool; Female; Humans; Leukotriene B4; Leukotriene C4; Male; Thromboxane A2

Monoterpenes are prescribed to treat chronic obstructive airway disorders mainly because of their familiar secretolytic properties. The aim of this study was to investigate the effect of 1.8-cineole (Soledum) on arachidonic acid (AA) metabolism in blood monocytes of patients with bronchial asthma. Patients with bronchial asthma (n = 10) and healthy test subjects (n = 12) were included in the study. Production of the representative AA-metabolites LTB4 and PGE2 from isolated monocytes stimulated with the calcium ionophore A23187 were measured ex vivo before therapy with 1.8-cineole (3 x 200 mg/day), after three days of treatment (day 4) and four days after discontinuation of 1. 8-cineole (day 8). The production of LTB4 and PGE2 from monocytes ex vivo was significantly inhibited on day 4 in patients with bronchial asthma (-40.3%, n = 10 and -31.3%, p = 0.1, n = 3 respectively) as well as in healthy volunteers (-57.9%, n = 12 and -42.7%, n = 8 respectively). In conclusion, 1.8-cineole was shown to inhibit LTB4 and PGE2, both pathways of AA-metabolism. Further studies are needed to show that 1.8-cineole is suitable in the treatment of bronchial asthma.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Asthma; Calcimycin; Cyclohexanols; Eucalyptol; Forced Expiratory Volume; Humans; Inflammation Mediators; Interleukin-1; Leukotriene B4; Menthol; Middle Aged; Monocytes; Monoterpenes; Terpenes

The aim of this study was to investigate eicosanoid metabolism by human peripheral blood monocytes (PBM) from steroid-dependent asthmatic patients as compared to control subjects and untreated asthmatic patients. Eicosanoid biosynthesis by PBM isolated from venous blood using Percoll gradient centrifugation was evaluated following stimulation of 5 x 10(6) cells with calcium ionophore A23187, with or without exogenous 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE), and analyzed by reverse phase high performance liquid chromatography (RP-HPLC). Without 15(S)-HETE, PBM synthesized leukotriene B4 (LTB4) only (40 +/- 12 ng and 59 +/- 11 ng for untreated and steroid-dependent asthmatics, respectively). In the presence of 15(S)-HETE, PBM produced six-fold smaller amounts of leukotriene B4 (P < 0.0001). They also released 5(S),15(S)-dihydroxyeicosatetraenoic acid (5(S),15(S)-diHETE) in similar amounts for all the populations, whereas low amounts of lipoxins (LXs) were produced by PBM from asthmatics only (2.7 +/- 0.7 ng and 4.6 +/- 2.8 ng for untreated and steroid-dependent asthmatics, respectively). Moreover, PBM were also able to release an unknown compound containing conjugated triene chromophore. Cells from steroid-dependent asthmatic patients synthesized this unknown metabolite in higher amounts than controls and untreated asthmatics (133 +/- 18 ng vs 52 +/- 19 ng and 68 +/- 15 ng, respectively, P < 0.02). This work shows for the first time that human PBM are able to metabolize 15(S)-HETE and lead to lipoxins and to an unknown metabolite, with the amounts of the latter being enhanced by long-term corticosteroid treatment.

Topics: Adrenal Cortex Hormones; Adult; Aged; Asthma; Eicosanoids; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Middle Aged; Monocytes

Leukotriene B4 (LTB4), a potent chemokinetic mediator for neutrophils, is enhanced by interleukin-8 (IL-8) and may play a key role in the inflammatory response of asthma.. The aim of the present study was to investigate whether zileuton, a 5-lipoxygenase antagonist known to inhibit LTB4 production and recruitment of eosinophils/neutrophils in bronchoalveolar fluid, could affect the production of LTB4 and IL-8 by allergen-stimulated peripheral blood mononuclear cells in vitro from patients with asthma and/or allergic rhinitis.. Peripheral blood mononuclear cells were isolated using Ficoll-Hypaque density gradient from 14 subjects (2 with asthma, 11 with asthma and allergic rhinitis, and 1 with allergic rhinitis) and were stimulated by selected allergens (grass, tree, mite, and mold) in the absence or presence of 1 and 10 microM of zileuton. Supernatants were collected and assayed for LTB4 and IL-8 levels using RIA and ELISA, respectively.. Levels of LTB4 were significantly elevated in peripheral blood mononuclear cells stimulated with mold, grass, and tree compared with the unstimulated control group (P<.05). Levels of IL-8 were significantly elevated in all allergen-stimulated peripheral blood mononuclear cells, except mold, compared with the unstimulated control group (P<.05). Zileuton significantly reduced production of LTB4 by mold and tree-stimulated peripheral blood mononuclear cells. By contrast, no effect of zileuton on IL-8 production was observed in allergen-stimulated peripheral blood mononuclear cells.. The zileuton-induced attenuation of LTB4 production by allergen-stimulated peripheral blood mononuclear cells from patients with asthma and/or allergic rhinitis occurs independently from the allergen-stimulated IL-8 production.

Topics: Adult; Aged; Allergens; Asthma; Female; Humans; Hydroxyurea; Interleukin-8; Leukocytes, Mononuclear; Leukotriene B4; Lipoxygenase Inhibitors; Male; Middle Aged; Rhinitis, Allergic, Perennial; Rhinitis, Allergic, Seasonal

Cineole (eucalyptol) is the isolated active agent of eucalyptus oil. Traditionally, it is recommended for treating the symptoms of airway diseases exacerbated by infection. We have examined the inhibitory effect of 1.8-cineole on LPS-and IL1beta-stimulated mediator production by human monocytes in vitro. For the first time, we report on a dose-dependent and highly significant inhibition of production of tumor necrosis factor-alpha, interleukin-1beta, leukotriene B4 and thromboxane B2 by 1.8-cineole. In summary, this is the first report on a new mechanism of action of monoterpenes suggesting 1.8-cineole as a strong inhibitor of cytokines that might be suitable for longterm treatment of airway inflammation in bronchial asthma and other steroid-sensitive disorders.

Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Asthma; Cyclohexanols; Cytokines; Eucalyptol; Female; Humans; In Vitro Techniques; Inflammation; Inflammation Mediators; Interleukin-1; Leukotriene B4; Lipopolysaccharides; Male; Menthol; Monocytes; Monoterpenes; Respiratory Tract Diseases; Terpenes; Thromboxane B2; Tumor Necrosis Factor-alpha

We examined the action of Shinpi-To (Formula divinita; TJ-85), a granular extract of seven Chinese medicinal herbs that is used in treating childhood asthma, on the leukotriene synthesis in rat basophilic leukemia-2H3 cells (RBL-2H3 cells). IgE-loaded cells were stimulated with anti-IgE serum in the presence or absence of Shinpi-To. Released LTC4 and LTB4 were measured by radioimmunoassay (RIA). Shinpi-To significantly inhibited IgE-mediated synthesis of leukotriene (LT)C4 and LTB4. To identify the inhibitory sites, we investigated the action of this extract on four synthetic enzymes, phospholipase A2 (PLA2), 5-lipoxygenase (5-LO). LTC4 synthase, and LTA4 hydrolase. Shinpi-To inhibited the A23187-stimulated release of [3H]arachidonic acid (AA) from the cell membrane, reflecting an effect on PLA2 activity. It also suppressed production of LTC4 and LTB4 when cell lysates were incubated with AA as substrate. It did not inhibit the production of LTC4 and LTB4 when LTA4-free acid was used as the substrate. Shinpi-To did not inhibit the IgE-mediated increase of intracellular Ca2+ ([Ca2+]i) concentration. Results indicate that Shinpi-To inhibits LT synthesis by inhibiting PLA2 and 5-LO activities without affecting the mobilization of [Ca2+]i.

Topics: Analysis of Variance; Animals; Arachidonic Acid; Asthma; Bronchodilator Agents; Calcimycin; Calcium; Cell Membrane; Drugs, Chinese Herbal; Ephedrine; Immunoglobulin E; Ionophores; Isotope Labeling; Leukemia, Basophilic, Acute; Leukotriene A4; Leukotriene B4; Leukotriene C4; Lipoxygenase Inhibitors; Phospholipases A; Phospholipases A2; Radioimmunoassay; Rats; Tritium; Tumor Cells, Cultured

It has been suggested that phospholipase A2 (PLA2) contributes to the regulation of leukotriene (LT) and platelet-activating factor (PAF) synthesis by controlling the release of their precursors, arachidonic acid (AA) and lysophosphatidylcholine (lysoPC), from membrane phospholipids. In rat alveolar macrophages (AMs), PLA2 appears to have a major role in LT synthesis but a more limited role in PAF synthesis. The present study was designed to define the role of PLA2 in LT and PAF synthesis in human AMs and determine whether differences exist between AMs obtained from normal subjects and those from patients with asthma. In the normal subjects, the calcium ionophore A23187 (Cal) increased AM PAF synthesis (percent incorporation of tritiated acetate) by 135% (p < 0.01) and LTB4 synthesis 88-fold (p < 0.001). Phorbol myristate acetate (PMA) had little effect alone, but it had a synergistic effect with Cal, increasing PAF synthesis by 466% and LTB4 synthesis to 229-fold above the control values (p < 0.001 for both). Ro 25-4331, a combined cytosolic (c) and secretory (s) PLA2 inhibitor, had little effect on the Cal-stimulated PAF synthesis, but it completely blocked the effect of PMA. It also blocked the Cal- and Cal+PMA-stimulated LTB4 synthesis. AACOCF3, a cPLA2 inhibitor, had no effect on either Cal or Cal+PMA-stimulated PAF synthesis. It reduced LTB4 synthesis, but it did so less effectively than Ro 25-4331. CoA-independent transacylase (CoAI-TA) activity in the AMs increased after stimulation and exposure to Ro 25-4331. SK&F 45905, a CoAI-TA inhibitor, reduced stimulated PAF synthesis by 30% to 40%. Patients with asthma had similar results except that cPLA2 had a greater role in stimulated LTB4 synthesis. These data indicate that PLA2 plays a direct role in human AM LT synthesis; both the cytosolic and secretory forms contribute to LT synthesis; PLA2 appears to have a more limited role in PAF synthesis, although it mediates the synergistic effect of PMA, probably via sPLA2; and CoAI-TA contributes to PAF synthesis during PLA2 inhibition. With the exception of the greater role for cPLA2 in stimulated LTB4 synthesis in the patients with asthma, the contributions of PLA2 and CoAI-TA to AM LT and PAF synthesis appear to be similar in normal subjects and patients with asthma.

Topics: Acetyltransferases; Acyl-Carrier Protein S-Acetyltransferase; Arachidonic Acids; Asthma; Benzenesulfonates; Bronchoalveolar Lavage Fluid; Calcimycin; Calcium; Cells, Cultured; Cytosol; Enzyme Inhibitors; Humans; Ionophores; Leukotriene B4; Leukotrienes; Macrophages, Alveolar; Phospholipases A; Phospholipases A2; Platelet Activating Factor; Tetradecanoylphorbol Acetate; Urea

A role of prostaglandins (PGs) and leukotrienes (LTs) in the pathogenesis of nasal polyps has been recently suggested. Cyclooxygenase (CO) products (thromboxane B2, PGE2 and 6-keto PGF1 alpha) and lipoxygenase (LO) products (LTB4 and LTC4) were investigated by radioimmunoassay in polyps, hypertrophic turbinates and nasal mucosa from 14 patients with non-allergic (n = 6), allergic chronic rhinitis (n = 6) and aspirin-sensitive asthma (ASA) (n = 2), who underwent polypectomy. In all tissues CO metabolite levels were found higher than LO products (P < 0.01). Nasal polyps showed a significantly lower (P < 0.05) arachidonic acid (AA) metabolism in comparison to nasal mucosa. In polyps of allergic patients significantly higher LTB4 levels (P < 0.001) and a tendency to produce higher amounts of CO products in comparison to non-allergic subjects were observed, whereas in turbinates of non-allergic patients LT levels were significantly higher in comparison to those of allergic ones (P < 0.01). In ASA patients a decreased CO/LO ratio was found supporting the hypothesis of an imbalance of AA metabolism in this syndrome. These findings seem to indicate that the occurrence of nasal polyps may represent the result of different chronic inflammatory stimuli, regulated in part by AA metabolites.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Arachidonic Acid; Asthma; Dinoprostone; Humans; Leukotriene B4; Leukotriene C4; Lipoxygenase; Middle Aged; Nasal Mucosa; Nasal Polyps; Prostaglandin-Endoperoxide Synthases; Rhinitis; Thromboxane B2; Turbinates

The role of platelet activating factor (PAF) in asthma remains controversial. The priming effect of PAF on leukotriene B4 (LTB4) release, 5-lipoxygenase activity, and intracellular calcium levels in asthmatic neutrophils was examined.. LTB4 and other lipoxygenase metabolites in neutrophils obtained from 17 asthmatic patients and 15 control subjects were measured by reverse phase-high performance liquid chromatography (RP-HPLC). Intracellular calcium levels were monitored using the fluorescent probe fura-2.. The mean (SD) basal LTB4, release from neutrophils was not significantly different between the two groups (0.05 (0.01) vs 0.03 (0.02) ng/10(6) cells); however, when stimulated with calcium ionophore A23187 (2.5 microM), neutrophils from asthma patients released more LTB4 than cells from control subjects (15.7 (1.2) vs 9.9 (1.6) ng/10(6) cells). Although PAF alone did not alter LTB4 release, it enhanced the response to subsequent A23187 stimulation. This effect was observed following treatment for five minutes with PAF at concentrations > 1.0 microM. The maximal effect was seen with 5.0 microM PAF + 2.5 microM A23187 (62.7 (2.2) vs 18.6 (2.3) ng/10(6) cells). Pretreatment with PAF also increased 5-lipoxygenase activity and intracellular calcium levels in neutrophils from asthmatic patients to a greater extent than in those from non-asthmatic patients.. These findings indicate that, in neutrophils from asthmatic patients, PAF enhances LTB4 release and increases 5-lipoxygenase activity and intracellular calcium to a greater extent than in neutrophils from non-asthmatic patients.

Topics: Adult; Arachidonate 5-Lipoxygenase; Asthma; Calcimycin; Calcium; Cells, Cultured; Cytosol; Female; Humans; Ionophores; Leukotriene B4; Male; Middle Aged; Neutrophils; Platelet Activating Factor; Stimulation, Chemical

To test the hypothesis that leukotriene (LT) B4 antagonists may be clinically useful in the treatment of asthma, CP-105,696 was evaluated in vitro, using chemotaxis and flow cytometry assays, and in vivo, using a primate asthma model. CP-105,696 inhibited LTB4-mediated monkey neutrophil chemotaxis (isolated cells, LTB4 = 5 nM) and CD11b upregulation (whole blood, LTB4 = 100 nM) with IC50 values of 20 nM and 16.5 microM, respectively. Using a modification of a previously described in vivo protocol (Turner et al. Am. J. Respir. Crit. Care Med. 1994. 149: 1153-1159), we observed that treatment with CP-105,696 inhibited the acute increase in bronchoalveolar lavage (BAL) levels of IL-6 and IL-8 by 56.9 +/- 13.2% and 46.9 +/- 14.5%, respectively, 4 h after challenge with Ascaris suum antigen (Ag). CP-105,696 tended to reduce the increase in BAL protein levels 0.5 h after Ag challenge by 47.5 +/- 18.3%, but this was not statistically significant. In addition, CP-105,696 prevented the significant 11-fold increase in airway responsiveness to methacholine after multiple Ag challenge. These results suggest that LTB4 partially mediates acute and chronic responses to antigen in an experimental primate asthma model and support the clinical evaluation of LTB4 antagonists in human asthma.

Topics: Animals; Asthma; Benzopyrans; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Carboxylic Acids; Chemotaxis, Leukocyte; Humans; Leukotriene B4; Macaca fascicularis; Macrophage-1 Antigen; Neutrophils; Receptors, Leukotriene B4; Up-Regulation

We examined the release of leukotriene B4 from calcium ionophore A23187-stimulated neutrophils from asthmatic patients treated with or without intravenous prednisolone during an asthmatic attack. The mean level of LTB4 in the supernatant of stimulated neutrophils from patients treated with intravenous prednisolone was significantly lower than that in the supernatant of stimulated neutrophils from those without prednisolone treatment. Preincubation with prednisolone caused a dose-dependent inhibition of LTB4 release from calcium ionophore A23187-stimulated neutrophils. These findings suggest that intravenous prednisolone inhibits the release of LTB4 from neutrophils in vivo.

Topics: Adult; Asthma; Calcimycin; Calcium; Cells, Cultured; Humans; Ionophores; Leukocyte Count; Leukotriene B4; Middle Aged; Neutrophils; Prednisolone; Secretory Rate

Bronchial asthma is accompanied with inflammatory cell infiltration in the airway. Because kinin activity was detected in bronchoalveolar lavage fluid (BALF) from asthmatic patients, and because the concentrations of kallikrein and kinins in BALF increased after allergen challenge, we evaluated the potential that bradykinin (BK) might stimulate alveolar macrophages (AM) to release neutrophil, monocyte, and eosinophil chemotactic activity (NCA, MCA, and ECA). To test this hypothesis, bovine AM were isolated by bronchoalveolar lavage and cultured. The supernatant fluids of AM were tested for chemotactic activity by a blind well chamber technique. AM released NCA, MCA, and ECA in response to BK in a dose-and time-dependent manner (p < 0.01). The released activities were chemotactic by checkerboard analysis. Partial characterization and molecular sieve column chromatography revealed that these released activities were heterogeneous, suggesting predominant low-m.w. lipid soluble activity and weak high-m.w. peptide activity. Lipoxygenase inhibitors blocked the release of chemotactic activities (p < 0.01). The chemotactic activities were partly inhibited by leukotriene B4 (LTB4) and platelet-activating factor (PAF) receptor antagonists (p < 0.05, respectively). Immunoreactive LTB4 significantly increased in supernatant fluids in response to BK (p < 0.05), but PAF was detected only two out of six samples stimulated by BK. The receptor responsible for the release of LTB4 involved both BKB1 and BKB2 receptors. These data suggest that BK may stimulate AM and play a role in bronchial inflammation by recruiting inflammatory cells into the airway.

Topics: Animals; Asthma; Bradykinin; Bronchoalveolar Lavage Fluid; Cattle; Chemotactic Factors, Eosinophil; Cytokines; Dose-Response Relationship, Drug; Humans; Interleukin-8; Leukotriene B4; Lipoxygenase Inhibitors; Macrophages, Alveolar; Molecular Weight; Monocyte Chemoattractant Proteins; Platelet Activating Factor; Platelet Membrane Glycoproteins; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Receptors, Leukotriene B4

Inhalation of antigen in immunized mice induces an infiltration of eosinophils into the airways and increased bronchial hyperreactivity as are observed in human asthma. We employed a model of late-phase allergic pulmonary inflammation in mice to address the role of leukotrienes (LT) in mediating airway eosinophilia and hyperreactivity to methacholine. Allergen intranasal challenge in OVA-sensitized mice induced LTB4 and LTC4 release into the airspace, widespread mucus occlusion of the airways, leukocytic infiltration of the airway tissue and broncho-alveolar lavage fluid that was predominantly eosinophils, and bronchial hyperreactivity to methacholine. Specific inhibitors of 5-lipoxygenase and 5-lipoxygenase-activating protein (FLAP) blocked airway mucus release and infiltration by eosinophils indicating a key role for leukotrienes in these features of allergic pulmonary inflammation. The role of leukotrienes or eosinophils in mediating airway hyperresponsiveness to aeroallergen could not be established, however, in this murine model.

Topics: 5-Lipoxygenase-Activating Proteins; Allergens; Animals; Asthma; Bronchial Provocation Tests; Bronchoconstrictor Agents; Carrier Proteins; Disease Models, Animal; Female; Immunoglobulin E; Inflammation; Leukotriene B4; Leukotriene C4; Lipoxygenase Inhibitors; Membrane Proteins; Methacholine Chloride; Mice; Mice, Inbred BALB C; Mucus; Ovalbumin; Pulmonary Eosinophilia; Respiratory Function Tests; Respiratory System

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

The ability of linetastine (TMK688, 1-[¿5'-(3"-methoxy-4"-ethoxycarbonyloxyphenyl)-2',4'-pentadieno yl¿ aminoethyl]-4-diphenylmethoxypiperidine, CAS 110501-66-1) to inhibit leukotriene production and to antagonize the effect of histamine was examined in comparison with the ability of azelastine, an antiallergic drug having an antihistamine activity. Linetastine and its active metabolite TMK777 (1-[¿5'-(3"-methoxy-4"-hydroxyphenyl)-2',4'-pentadienoyl¿ aminoethyl]-4-diphenylmethoxypiperidine, CAS 101619-11-8) inhibited the release of leukotrienes B4 and C4 from calcium ionophore-stimulated human leukocytes. The respective IC50 values of leukotriene B4 were 1.2 x 10(-7) mol/l and 8.6 x 10(-8) mol/l, and those of leukotriene C4 were 1.5 x 10(-7) mol/l and 7.1 x 10(-8) mol/l. Azelastine also inhibited the release of leukotriene B4 and C4, but its IC50 values were higher than 1 x 10(-5) mol/l. Linetastine at 1-10 mg/kg p.o. inhibited the increase in leukotriene B4 and C4 production in the lungs during late asthmatic responses in actively sensitized guinea-pigs. The effect of 3.2 mg/kg lasted for more than 16 b. Since repeated oral administration of linetastine, 1 mg/kg once a day for 7 successive days, showed the same inhibitory effect on the increase in respiratory resistance and the leukotriene production as single oral administration, the effect of linetastine was neither tachyphylactic nor cumulative. Azelastine at 10 mg/kg had no effect on the leukotriene production. Linetastine TMK777 and azelastine dose-dependently inhibited the histamine-induced contraction of isolated guinea-pig trachea in a noncompetitive manner, the respective pD2 values were 7.28, 7.98 and 8.07. Linetastine inhibited histamine-induced bronchoconstriction dose-dependently at 1-10 mg/kg (p.o.) in guinea-pigs, and the effect lasted for more than 24 h. Repeated oral administration of linetastine, 0.32 to 3.2 mg/kg once a day for 7 successive days inhibited the histamine-induced bronchoconstriction, the same as single oral dosing. Azelastine at 0.32 mg/kg p.o. also showed antihistamine activity. In conclusion, linetastine inhibits both the production of leukotrienes and the effect of histamine at almost the same dose and the effects were long lasting.

Topics: Animals; Arachidonate 5-Lipoxygenase; Asthma; Bronchoconstriction; Female; Guinea Pigs; Histamine Antagonists; Humans; In Vitro Techniques; Leukocytes; Leukotriene B4; Leukotriene C4; Lipoxygenase Inhibitors; Lung; Male; Mammary Neoplasms, Experimental; Mast-Cell Sarcoma; Mice; Piperidines; Stimulation, Chemical; Trachea; Tumor Cells, Cultured

Topics: Adult; Animals; Asthma; Benzoates; Child; Child, Preschool; Dogs; Guinea Pigs; Humans; Infant; Leukotriene B4; Lymphokines; Rats; Receptors, Leukotriene B4

Eosinophils generate and release leukotrienes C4 and B4 (LTC4, LTB4) and platelet activating factor (PAF), all of which have the capacity to cause inflammation and tissue injury in the airways. This study has examined the effects of a new 5-lipoxygenase inhibitor, 6-hydroxy-2-(4-sulfamoylbenzylamino)-4,5,7-trimethylbenzothiazo le hydrochloride (CAS 120164-49-0, E6080) on the release of LTC4, LTB4 and PAF by human eosinophils, Eosinophils stimulated by 1 mumol/l calcium ionophore A23187 for 15 min released 37.5 +/- 2.2 ng, 2.3 +/- 0.3 ng and 4.0 +/- 0.3 pmol per 10(6) cells of immunoreactive LTC4, LTB4 and PAF, respectively (mean +/- SEM, n = 4). LTC4 and LTB4 releases were inhibited dose-dependently by the addition of E6080 to the cell suspension. The IC50 values were 0.26 mumol/l for LTC4 and 0.23 mumol/l for LTB4. PAF release was not inhibited. These results suggest that E6080 is a potent inhibitor of LTC4 and LTB4 release from eosinophils and may provide a protective effect against bronchoconstriction during late-phase asthmatic responses.

Topics: Asthma; Calcimycin; Dose-Response Relationship, Drug; Eosinophils; Humans; In Vitro Techniques; Ionophores; Leukotriene B4; Leukotriene C4; Lipoxygenase Inhibitors; Platelet Activating Factor; Thiazoles

Leukotrienes may mediate bronchoconstriction in asthma. Cysteinyl leukotriene production rises in vivo after allergen challenge, but few reports describe leukotriene concentrations in clinical asthma or in children. Using high performance liquid chromatography/radioimmunoassay, plasma and urinary leukotrienes in asthmatic children (aged 5-10 years) were measured during an acute exacerbation (peak expiratory flow (PEF) < 65%, n = 10) and one month later (PEF 74-169%, n = 9), and in non-atopic normal children (aged 1.3-13.2 years). In the asthmatics, geometric mean (95% confidence interval) plasma leukotriene B4 (LTB4) was 746 pg/ml (398 to 1403) acutely and 1026 pg/ml (662 to 1593) in remission, compared with 369 pg/ml (167 to 728) in the normal children (n = 14). Plasma cysteinyl leukotrienes were low or undetectable, but urinary leukotriene E4 (LTE4) was higher in the asthmatics during an acute episode (210 pmol/mmol creatinine, 101 to 454) and at follow up (179 pmol/mmol, 110 to 293), compared with the normal children (98 pmol/mmol, 81 to 118, n = 41). This persistent increase in plasma LTB4 and urinary LTE4 concentrations one month after a severe asthmatic episode suggests leukotriene production is related to chronic inflammation rather than to acute bronchoconstriction.

Topics: Acute Disease; Adolescent; Asthma; Child; Child, Preschool; Chromatography, High Pressure Liquid; Humans; Leukotriene B4; Leukotriene C4; Leukotriene E4; Radioimmunoassay

To determine the role of neutrophil elastase in asthmatic responses, we studied the effect of ONO-5046, a specific neutrophil elastase inhibitor, on antigen-induced asthmatic responses in allergic sheep. Pulmonary resistance (RL) was measured for 8 h after antigen challenge. Measurements of airway responsiveness to methacholine and bronchoalveolar lavage fluid (BALF) were obtained 8 h after challenge. Antigen challenge caused early and late increases in RL, airway hyperresponsiveness (AHR), and recruitment of neutrophils and eosinophils along with increases in TXB2 and LTB4 in BALF. ONO-5046 treatment significantly reduced both early and late bronchoconstriction, neutrophil recruitment, increases in LTB4 in BALF, and AHR. ONO-5046 post-treatment significantly reduced the increase in RL 8 h after antigen challenge. Another neutrophil elastase inhibitor, FR 134043, significantly reduced both early and late bronchoconstriction. ONO-5046 had little effect on calcium ionophore-induced LTB4 release from isolated neutrophils and whole blood obtained from drug-treated sheep. These findings suggest that neutrophil elastase is involved in antigen-induced bronchoconstriction and AHR mediated by neutrophil accumulation and 5-lipoxygenase products in allergic sheep.

Topics: Airway Resistance; Animals; Antigens; Asthma; Benzoquinones; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Bronchoconstriction; Calcimycin; Glycine; Heterocyclic Compounds; Leukocyte Elastase; Leukocytes; Leukotriene B4; Masoprocol; Methacholine Chloride; Pancreatic Elastase; Polycyclic Compounds; Sheep; Sulfonamides; Thromboxane B2

Leukotriene B4 (LTB4) serum and plasma concentrations were reported to be higher in some asthmatic patients than in normal subjects; however, reported LTB4 concentrations in normal subjects vary widely. One study suggested that blood clotting causes the increased LTB4 concentration.. To determine whether LTB4 concentration is increased in asthmatic patients, and whether it is affected by clotting.. We studied seven normal subjects and nine clinically stable asthmatic patients. Venous blood was drawn into test tubes without additives; containing heparin; or containing heparin and cyclo- and lipoxygenase inhibitors. Cells were separated after 30 minutes. Leukotriene B4 was measured by radioimmunoassay following its extraction from serum or plasma. In three subjects, plasma was separated also at times 0 through 30 minutes.. Serum and plasma concentrations of LTB4 in normal volunteers and asthmatic patients were similar, but the variance of LTB4 concentrations among the asthmatic patients was significantly higher than in the normal subjects. Leukotriene B4 concentrations, measured in plasma only, were significantly reduced in both asthmatic and nonasthmatic subjects in the presence of inhibitors. There was no significant difference in LTB4 concentrations between time 0 and 30 minutes, but there was considerable variability.. We conclude that clotting is unlikely to affect serum LTB4 concentrations. Leukotriene B4 serum and plasma concentrations are not consistently increased in asthmatic patients; however, LTB4 is synthesized during and possibly after blood has been drawn. Proper handling of the specimens and probably the addition of cyclo-oxygenase and lipoxygenase inhibitors is of the utmost importance for accurate LTB4 determination.

Topics: Adult; Asthma; Blood Coagulation; Female; Humans; Leukotriene B4; Male; Middle Aged

Mucosal inflammatory processes in late phase of allergic diseases involve cytokine production, cell adhesion molecule overexpression and release of inflammatory mediators with chemotactic activity, such as leukotriene B4 (LTB4). We had previously observed increased production of LTB4 by neutrophils in patients with allergic rhinitis and discussed the role of granulocyte macrophage-colony stimulating factor (GM-CSF) priming. Some antihistaminic compounds were shown to diminish the production of leukotrienes by neutrophils.. In a first step, we evaluated in ex vivo and in vitro studies, the effects of cetirizine on LTB4 production by blood neutrophils from allergic and healthy subjects. In a second step, we studied the in vitro effect of cetirizine on LTB4 production by neutrophils from healthy subjects during GM-CSF priming of these cells.. Neutrophils from both populations were purified from venous blood and LTB4 production was measured using high performance liquid cromatography (HPLC) method.. In ex vivo studies, cetirizine treatment induced a decreased LTB4 production by neutrophils in allergic rhinitis. This effect of decreased LTB4 production was reproduced in vitro with 10(-8)-10(-6)M cetirizine. Nevertheless, this anti-H1 compound had no effect on neutrophil priming with GM-CSF.. As LTB4 is an important chemotactic factor, Cetirizine could act on inflammatory cell recruitment by inhibiting LTB4 production by neutrophils.

Topics: Adult; Anti-Allergic Agents; Asthma; Cetirizine; Female; Granulocyte-Macrophage Colony-Stimulating Factor; Histamine H1 Antagonists; Humans; Leukotriene B4; Male; Middle Aged; Neutrophils; Rhinitis, Allergic, Perennial

Plasma from bronchial asthma patients and healthy controls was investigated for the content of lipoxygenase products. After lipid extraction using SEP-PAK C18 Cartridges, the lipoxygenase products were measured by Enzyme-Immunoassay. Elevated chemotactic B4 was found in plasma from asthmatic patients with mean value (483 +/- 75) pmol/L, while the mean value in normal healthy donors was (140 +/- 12.1) pmol/L (M +/- SE). The levels of spasmogenic cysteinyl containing leukotrienes were also very high in the bronchial asthma patients. Elevations of leukotriene B4 and cysteinyl containing leukotrienes were detected during attacks of bronchial asthma. These results suggest that leukotriene B4 may be important in the pathogenesis of bronchial asthma and confirmed that peptidoleukotrienes play a role as chemical mediators during the asthmatic attack.

Topics: Asthma; Humans; Leukotriene B4; Leukotriene C4

Aspirin-sensitive patients may be desensitized through a graded series of exposures to aspirin. We investigated the underlying mechanism of aspirin desensitization by measuring the release of leukotrienes B4 and C4 from calcium ionophore-stimulated peripheral blood monocytes. Compared with monocytes from normal volunteers (n = 5), monocytes from patients with aspirin-sensitive asthma (n = 10) released increased amounts of thromboxane B2 (1060 +/- 245 pg/ml vs 456 +/- 62 pg/ml), leukotriene B4 (861 +/- 139 pg/ml vs 341 +/- 44 pg/ml), and leukotriene C4 (147 +/- 31 pg/ml vs 56 +/- 6 pg/ml) at baseline. After aspirin desensitization, thromboxane B2 release was almost completely suppressed in both groups. Leukotriene B4 release was significantly decreased in the aspirin-sensitive group (484 +/- 85 pg/ml) but not in the normal subject group (466 +/- 55 pg/ml). The need for prednisone decreased significantly after patients were desensitized to aspirin (10.4 +/- 2.2 mg/day to 1.6 +/- 2.8 mg/day). These results demonstrate that desensitization to aspirin results in decreased monocyte leukotriene B4 release. On the basis of the bronchospastic and inflammatory potential of leukotrienes, the decrease in leukotriene release may contribute to the clinical improvement seen after aspirin desensitization.

Topics: Adult; Aspirin; Asthma; Desensitization, Immunologic; Female; Humans; Leukotriene B4; Leukotriene C4; Male; Middle Aged; Monocytes; Thromboxane B2

Prednisolone is very effective in controlling wheezing attacks of bronchial asthma, but its mechanism and the pathogenic role of leukotriene B4 remain unclear. We measured changes in plasma levels of leukotriene B4 in an open study during the clinical course of bronchial asthma, with or without water-soluble prednisolone treatment. Two millilitres of blood was drawn from the radial artery of patients on three occasions: 1) during remission; 2) on admission to hospital with an asthma attack; and 3) 2 days after admission and treatment with intravenous prednisolone (1,000 mg.day-1). Leukotriene B4 was detected by chromatographic fractionation and radioimmunoassay. In 11 asthmatic patients, leukotriene B4 levels on the three occasions were 26.8 (10.7), 106.0 (39.9) and 51.6 (20.2) pg.ml-1 (mean (SD)), respectively. In contrast, the mean leukotriene B4 level of 10 normal controls was 35.9 (10.5) pg.ml-1. Leukotriene B4 levels differed significantly between remission and attack treated without prednisolone, and between attacks treated with and without prednisolone. Mean arterial carbon dioxide (PaCO2) values were 4.8 (0.4) kPa (36.0 (3.0) mmHg), 6.1 (0.4) kPa (45.6 (2.9) mmHg), and 5.5 (0.3) kPa (41.6 (2.0) mmHg), respectively. There were significant differences between these mean PaCO2 values. The mean leukotriene B4 levels on the three occasions were correlated with the mean PaCO2 values. Thus, leukotriene B4 levels in arterial blood reflect the severity of asthmatic attacks and may be affected by intravenous prednisolone.

Topics: Adult; Aged; Asthma; Carbon Dioxide; Case-Control Studies; Chemotaxis, Leukocyte; Chromatography, High Pressure Liquid; Humans; Injections, Intravenous; Leukotriene B4; Male; Middle Aged; Neutrophils; Prednisolone; Radioimmunoassay

Peptidoleukotrienes may be important mediators of human bronchial asthma. Accordingly, the effects of a selective leukotriene (LT) biosynthesis inhibitor (MK-0591) were assessed in allergic dogs characterized by acute bronchoconstriction and subsequent airway hyperresponsiveness induced by inhaled ragweed allergen. Peak acute increases in airway resistance (Rrs) induced by ragweed were associated with increased bronchoalveolar lavage histamine concentration, and neither parameter was inhibited by MK-0591 (8 micrograms.kg-1.min-1 i.v.). However, the duration of the bronchoconstriction was significantly decreased by MK-0591, with a reduction in the area under the curve of 40% (P < 0.05). Associated with the acute bronchoconstriction in placebo-treated animals was a fivefold increase in urinary LTE4 excretion (as seen with allergic asthmatic patients), which was reduced to < 10% of basal values by MK-0591. Similarly, whole blood LTB4 biosynthesis was abolished in the MK-0591-treated animals. Bronchial hyperresponsiveness preallergen (measured as the percent concentration of acetylecholine required to increase Rrs by 5 cmH2O.l-1.s) tended to improve with MK-0591 (0.41 +/- 0.15 vs. 0.23 +/- 0.05%). Five hours after allergen inhalation, the percent concentration declined substantially in the placebo group (0.07 +/- 0.02%; P < 0.01), revealing an increased airway responsiveness that was significantly blunted by MK-0591 (0.26 +/- 0.07%; P < 0.001). These data suggest that selective inhibition of LT biosynthesis by novel compounds such as MK-0591 may modify the airway changes associated with bronchial hyperresponsiveness, as well as offer symptomatic relief in asthma.

Topics: 5-Lipoxygenase-Activating Proteins; Airway Resistance; Allergens; Animals; Asthma; Bronchoalveolar Lavage Fluid; Carrier Proteins; Dogs; Histamine; Indoles; Leukotriene Antagonists; Leukotriene B4; Leukotriene E4; Leukotrienes; Membrane Proteins; Quinolines; Respiratory Hypersensitivity

The peptidoleukotrienes and leukotriene B4, formed from arachidonic acid through the action of 5-lipoxygenase (5-LO), exert a spectrum of biological effects. It has been proposed that potent and selective 5-LO inhibitors will be effective therapy in diseases in which the peptidoleukotrienes and leukotriene B4 have been implicated, such as asthma and arthritis. The novel compound (S)-N-hydroxy-N-(2,3-dihydro-6-phenylmethoxy-3-benzyofuranyl )urea (SB 202235) was evaluated as a selective inhibitor of 5-LO in a cell-free system as well as in various cellular assays. In addition, the potential therapeutic value of SB 202235 was assessed in preclinical models of allergic asthma. The activity of the 5-LO enzyme isolated from rat basophilic leukemia-1 cells was inhibited by SB 202235 in a concentration-dependent manner with an IC50 value of 1.9 microM. Consistent with its ability to inhibit 5-LO, SB 202235 inhibited the production of leukotriene B4 by human monocytes and in human whole blood (IC50 values of 1.5 microM and 1.1 microM, respectively). The selectivity of SB 202235 was confirmed by its lack of effect against several other enzymes and receptors. SB 202235 potently and effectively inhibited the contraction produced by a single concentration of ovalbumin in guinea pig trachea (IC50 = 20 microM) and of anti-IgE in human bronchus (IC50 = 2 microM). SB 202235 (3-30 microM) also inhibited the contraction of guinea pig trachea in response to increasing concentration of ovalbumin. When administered orally (30 mg/kg) to conscious guinea pigs, SB 202235 attenuated antigen-induced broncho-constriction and the subsequent eosinophil influx.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Antigens; Asthma; Benzofurans; Bronchoconstriction; Disease Models, Animal; Eosinophils; Guinea Pigs; Humans; Hypersensitivity; In Vitro Techniques; Leukotriene B4; Lipoxygenase Inhibitors; Trachea; Urea

Leukotrienes are inflammatory mediators implicated in the pathogenesis of asthma. The capacity of inflammatory cells within the airways to generate leukotrienes may be altered in asthma. This hypothesis was tested using bronchoalveolar lavage (BAL) to sample cells within the airways from atopic asthmatic and normal subjects, and by measuring their capacity to generate leukotriene B4 (LTB4) and leukotriene C4 (LTC4) in response to A23187, a potent stimulus of leukotriene generation.. Bronchoalveolar lavage was performed in 12 mild asymptomatic atopic asthmatic patients and 12 normal subjects. Mixed BAL cell aliquots (approximately 80% alveolar macrophages) were incubated with 0-20 microM A23187 for 10 minutes and with 4 microM A23187 for 0-30 minutes, and leukotrienes were measured by radioimmunoassay and high performance liquid chromatography.. Mixed BAL cells from asthmatic subjects generated less LTB4 than cells from normal subjects in dose response and time course experiments (area under the curve 81.5 (0.0-228.5) ng.min.10(-6) cells in asthmatic subjects and 197.9 (13.9-935.6) ng.min.10(-6) cells in normal subjects. There were no differences in LTC4 generation between BAL cells from asthmatic and normal subjects.. Generation of LTB4 by BAL cells from atopic asthmatic subjects in response to A23187 was reduced. As the alveolar macrophage is the major source of LTB4 in BAL cells, these results probably reflect reduced generation of LTB4 by alveolar macrophages from asthmatic patients. This may be a consequence of monocyte migration into the lung, or altered alveolar macrophage function in asthma, or both.

Topics: Adult; Asthma; Bronchoalveolar Lavage Fluid; Calcimycin; Cell Count; Chromatography, High Pressure Liquid; Female; Humans; Leukotriene B4; Leukotriene C4; Macrophages, Alveolar; Male; Radioimmunoassay

The ex vivo release of leukotriene B4 (LTB4) and leukotriene C4 (LTC4) from leukocytes was evaluated after stimulation with both Ca-ionophore (Ca-I) and opsonized zymosan (OZ) in children with atopic asthma. Twenty-seven patients with asthma of varying severity were evaluated and divided into three groups: 1) moderate to severe asthma using inhaled steroids and symptom-free for the last 3 weeks (n = 8), 2) mild asthma with sporadic symptoms, only using inhaled beta 2-agonists < 3 times/week (n = 8), and 3) acute asthmatic attacks admitted to hospital (n = 11). A group of children without atopic disease or any other known disease served as controls (n = 15). Total serum IgE levels were significantly increased in the children with asthma compared with the control group. LTC4 production was only significantly increased in the group of children with moderate to severe asthma after stimulation with Ca-I, when compared with controls. In the same group, a trend towards increased LTC4 production after stimulation with OZ was found. LTB4 was not significantly increased in any patient group compared with the control group. A significant correlation between LTC4 production after stimulation with Ca-I, but not OZ, and the relative blood eosinophil count was found in all subjects. LTC4 generation per eosinophilic cell after stimulation with Ca-I or OZ was not statistically different in any patient group compared with the controls. We conclude that the increased leukotriene (LT) levels found after the stimulation of peripheral white blood cells sampled from atopic children with asthma are mainly the result of increased numbers of LT-producing cells, rather than due to increased releasability from these cells.

Topics: Adolescent; Asthma; Calcimycin; Child; Child, Preschool; Humans; Hypersensitivity, Immediate; Immunoglobulin E; Leukocytes; Leukotriene B4; Leukotriene C4; Opsonin Proteins; Zymosan

We have tested the effect of methotrexate (MTX) on platelet activating factor (PAF)-induced neutrophil and eosinophil locomotion, neutrophil leukotriene B4 (LTB4) generation and mononuclear cell DNA synthesis. Neutrophils from patients treated with low dose methotrexate showed reduced PAF-induced chemotactic responses (727.8 +/- 72.2/10 HPF vs 481.9 +/- 87.3/10 HPF, p < 0.05). Both MTX and the specific PAF antagonist BN-52021 significantly inhibited PAF-induced eosinophil and neutrophil locomotion in a dose-dependent manner. MTX also reduced calcium ionophore-driven LTB4 generation from the neutrophils of asthmatics (358.9 +/- 39.5 pg/10(6) cells vs 240.1 +/- 29.1 pg/10(6) cells, p < 0.05) and attenuated PHA-induced mononuclear DNA synthesis as shown by a reduction in 3H-thymidine uptake and propidium iodide staining. These findings support the view that the beneficial effects of MTX in asthma may be due not only to its anti-mitotic effects on the proliferation of mononuclear cells but also to direct effects on granulocyte locomotion and production of LTB4.

Topics: Asthma; Chemotaxis, Leukocyte; Dose-Response Relationship, Drug; Eosinophils; Humans; Leukocytes, Mononuclear; Leukotriene B4; Methotrexate; Neutrophils; Platelet Activating Factor

Nedocromil sodium, a disodium salt of a pyroquinolinedicarboxylic acid, raises the bronchial hyperresponsiveness threshold, because it inhibits the mediators released by the various cells, and reduces the involvement and activation of inflammatory cells. The aim of this study was to evaluate the state of activation of the immunocompetent cells and the main chemical mediators present in the bronchoalveolar lavage (BAL) fluid from 10 atopic asthmatic patients, before and after treatment with nedocromil sodium. The following examinations were performed before treatment and after 120 days of therapy with nedocromil sodium at 16 mg/day (two 2-mg puffs x 4): the level of chemical mediators and the state of activation of immunocompetent cells in BAL fluid; immunological analytes in activation of immunocompetent cells in BAL fluid; immunological analytes in peripheral blood; aspecific bronchial challenge test with ultrasonicated bidistilled H2O fog to evaluate variations in the hyperreactivity threshold; questionnaire to determine any adverse effects of treatment (cough, breathlessness, sleep disorders). Our findings demonstrate that nedocromil sodium prevents the release of chemotactic and inflammatory mediators by the effector cells and thus stabilizes microvascular permeability and epithelial damage, so raising the threshold of response to bronchoconstriction stimuli. Lastly, nedocromil sodium is associated with a better preventive therapeutic efficacy and good tolerance and can therefore be suggested as a valid drug to be used in the long-term treatment of bronchial asthma.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Albumins; Asthma; Blood Proteins; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Dinoprostone; Eosinophil Granule Proteins; Humans; Hypersensitivity; Immunoglobulins; Immunologic Factors; Leukocytes; Leukotriene B4; Lymphocytes; Macrophages; Male; Nedocromil; Peptide Hydrolases; Ribonucleases; Thromboxane B2

Topics: Airway Obstruction; Asthma; Bronchoconstriction; Humans; Leukotriene Antagonists; Leukotriene B4; Leukotriene C4; Leukotriene E4; Leukotrienes

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

The objective of this study was to determine whether exposure to ozone causes inflammatory or functional changes in the upper or lower airways of asthmatic and nonasthmatic individuals. Ten asthmatic and eight nonasthmatic subjects were exposed to clean air, 120 ppb ozone, or 240 ppb ozone for 90 min during intermittent moderate exercise using a head dome exposure system. Pulmonary function tests, posterior rhinomanometry, and nasal lavage were performed before and after exposure. Leukocyte counts and chemotactic factors leukotriene B4 (LTB4), platelet-activating factor (PAF), and interleukin-8 (IL-8) were analyzed from nasal lavage fluid. In subjects with asthma, a significant increase (p < 0.05) in the number of white blood cells in lavage fluid was detected both immediately and 24 h after exposure to 240 ppb ozone, as was a significant increase in epithelial cells immediately after exposure (p < 0.05). No significant cellular changes were seen in nonasthmatic subjects. A significant correlation was observed between IL-8 and white blood cells counts after exposure to 240 ppb ozone (r = 0.76) in asthmatic subjects. No significant changes in pulmonary or nasal function or biochemical mediators were found in either the asthmatic or nonasthmatic subjects. These data indicate that asthmatic individuals are more sensitive to the acute inflammatory effects of ozone than nonasthmatic individuals.

Topics: Adolescent; Adult; Asthma; Female; Histamine; Humans; Inflammation; Interleukin-8; Leukocyte Count; Leukotriene B4; Male; Nasal Lavage Fluid; Ozone; Platelet Activating Factor; Respiratory Mechanics; Respiratory System

Immunoallergological studies were carried out to clarify the differences between 24 patients with drug-induced asthma (DIA) and 240 with non-drug-induced asthma (non-DIA). The mean values of age, skin reaction to Candida albicans (C. albicans), serum IgE levels, specific IgE antibodies to house dust (HD) and C. albicans, bronchial sensitivity and leukotriene B4 (LTB4) synthesis from peripheral venous blood in patients with DIA were not significantly different from those in patients with non-DIA. In contrast, the frequency of positive skin reaction to HD and histamine release from peripheral basophils by anti-IgE were significantly lower in DIA than in non-DIA. These results agree with the reports that DIA was often observed in non-atopic asthma. But, the mean value of serum IgE was very high in DIA as well as in non-DIA. This result suggests that IgE mediated reaction in DIA is important. Furthermore, the proportion of neutrophils in bronchoalveolar lavage fluid (BALF) was significantly lower in DIA than in non-DIA. Our findings suggest that a decrease of intrapulmonary neutrophils might play an important role in the pathophysiology of DIA.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies; Asthma; Bronchi; Bronchoalveolar Lavage Fluid; Candida albicans; Child; Child, Preschool; Drug Hypersensitivity; Dust; Female; Histamine Release; Humans; Immunoglobulin E; Immunoglobulin M; Leukotriene B4; Male; Methacholine Chloride; Middle Aged; Radioallergosorbent Test; Retrospective Studies; Skin Tests

The proportion of inflammatory cells in bronchoalveolar lavage (BAL) fluid and the release of chemical mediators from BAL and peripheral blood cells were examined in 40 patients with steroid-dependent intractable asthma (SDIA) to clarify the effects of a long-term glucocorticoid regimen on these cells. The proportion of BAL lymphocytes was significantly reduced (p < 0.01) and the proportion of BAL neutrophils was significantly increased (p < 0.01) in SDIA patients compared with non-SDIA patients. The proportion of basophilic cells (mast cells and basophils) in BAL fluid was significantly lower in SDIA patients compared to non-SDIA patients (p < 0.02). The values of six ventilatory parameters were significantly lower in SDIA patients with a high proportion of BAL neutrophils (more than 10%) compared with the values in non-SDIA patients. The release of histamine and leukotriene C4 (LTC4) from the BAL cells of patients with atopic asthma was significantly reduced in SDIA patients compared with non-SDIA patients (p < 0.05). These results show that the changes in the proportion of BAL cells are observed in patients with SDIA, and these changes are related to suppressed ventilatory function and a reduction in the release of histamine and LTC4 from BAL cells.

Topics: Adult; Aged; Asthma; Basophils; Bronchoalveolar Lavage Fluid; Chronic Disease; Female; Histamine Release; Humans; Leukocyte Count; Leukotriene B4; Leukotrienes; Lymphocytes; Male; Middle Aged; Neutrophils; Prednisolone; Respiratory Function Tests; SRS-A

We measured changes in plasma levels of leukotriene B4 (LTB4) during the clinical course of bronchial asthma. Samples of 2 ml of blood were drawn from the femoral artery of 5 patients on two occasions: a) during remission and b) during an attack. LTB4 levels were determined by a combination of high-performance chromatography with radioimmunoassay. In the 5 asthmatic patients, the LTB4 levels (mean +/- S.D.) on the two occasions were respectively 34.2 +/- 8.6 and 118.0 +/- 49.5 pg/ml. In contrast, the mean LTB4 level of 5 control subjects was 23.5 +/- 3.77 pg/ml. LTB4 levels differed significantly between remission and an attack. The corresponding mean PaCO2 values on the two occasions were respectively 37.7 +/- 1.8 and 47.3 +/- 2.2 mmHg. LTB4 showed good correlation with PaCO2. We therefore suggest that leukotriene B4 levels in arterial blood are associated with the severity of asthmatic attacks.

Topics: Adult; Aged; Asthma; Chromatography, High Pressure Liquid; Humans; Leukotriene B4; Male; Middle Aged; Radioimmunoassay; Severity of Illness Index

In allergic and nonallergic asthma, eosinophils play an important effector role. However, because the pathogenesis of these types of asthma seems different, the mechanisms responsible for the tissue mobilization of those cells may be different. The in vivo and in vitro migratory response of eosinophils from patients with allergic and nonallergic asthma toward 20-hydroxy-leukotriene B4 (20-OH-LTB4), which is reported here, illustrates this.. By means of the Rebuck skin window technique the in vivo skin mobilizing capacity of intracutaneously applied buffer, LTB4, and 20-hydroxy (OH)-LTB4 was evaluated in healthy subjects (n = 6), subjects with allergic asthma (n = 14), and subjects with nonallergic asthma (n = 17). Also the in vitro chemotactic responsiveness of eosinophils from the circulation of both patient groups (both n = 8) toward buffer, LTB4, and 20-OH-LTB4 were tested by use of a microchemotaxis chamber technique.. Although none of the substances were capable of inducing macroscopic observable skin reactions, intracutaneously applied 20-OH-LTB4 had an almost similar capacity to mobilize eosinophils in the skin of the subjects with nonallergic asthma as allergens had in subjects with allergic asthma. In 92% of the tested subjects with nonallergic asthma significant skin eosinophilia was observed. By contrast, LTB4 did not induce significant skin eosinophilia in both patient groups compared with buffer solution. This in vivo eosinophil mobilizing capacity of 20-OH-LTB4 in subjects with nonallergic asthma was confirmed by in vitro chemotaxis studies. Dose ranges of both LTB4 and 20-OH-LTB4 proved to be potent chemoattractants for eosinophils from patients with nonallergic asthma, but not for those of healthy subjects and those with allergic asthma.. Our results indicate that 20-OH-LTB4 may be involved in the tissue mobilization of eosinophils in nonallergic asthma and that in vitro 20-OH-LTB4 (and LTB4) may act as potent chemotactic factors on eosinophils from those patients.

Topics: Adult; Asthma; Chemotaxis, Leukocyte; Eosinophils; Female; Humans; Hypersensitivity; Leukotriene B4; Male; Reference Values; Skin; Skin Window Technique

The aim of this study was to evaluate by cytofluorimetry, the phenotype and the activation of alveolar macrophages (CD14; CD33; CD44; CD54; CD23; HLA-DR) and, by radioimmunoassay, the "in vivo and in vitro" macrophage secretory pattern (IL-1 alpha; IL-1 beta; IL6; IL8; PGE2; PGD-1 alpha; TXB2; LTB4) in atopic patients with mild asthma in intercritical phase and with bronchial hyperreactivity (PD20 FEV1 = 377 +/- 262.8 micrograms). In asthmatic patients we have demonstrated that the number of cells recovered in BALF expressing the phenotypic features (CD14; CD33; HLA-DR; CD23; CD44; CD54) was larger than in control subjects. By analysing the culture medium of unstimulated and LPS-stimulated alveolar macrophages from asthmatic and normals we have demonstrated a greater production of IL-1 beta (p = 0.005) and IL-8 (p = 0.005) in the first group than in one second, as confirmed by a Wilcoxon test. Concerning the secretory pattern in BALF of asthmatic patients we obtained similar results, showing a significant IL-1 beta (p = 0.005) and IL-8 (p = 0.002) increase suggesting a persistent cellular activation. On the contrary we could not show any significant increase of IL-1 alpha (p = 0.31) and IL-6 (p = 0.22). The cellular activation was confirmed by increased levels of different chemical mediators such as TXB2 (p = 0.005); LTB4 (p = 0.004); PGE2 (p = 0.007); PGF-1 alpha (p = 0.008) which were recovered from BALF of asthmatic patients compared to normal subjects. In conclusion alveolar macrophages play an important role in the pathogenesis of asthma because of the presence of cytokines and mediators in BALF and in the supernatant of alveolar macrophage cultures.

Topics: Adult; Asthma; Biopsy; Bronchi; Bronchoalveolar Lavage Fluid; Bronchoscopy; Cytokines; Flow Cytometry; Humans; Interleukins; Leukotriene B4; Macrophage Activation; Macrophages, Alveolar; Phenotype; Prostaglandins; Radioimmunoassay; Thromboxane B2

The bronchoconstrictor potency of inhaled methacholine is widely used to assess airway responsiveness. However, evidence has accumulated that methacholine inhalation challenge may lead to an inflammatory response in the lower respiratory tract. We therefore compared cellular, leukotriene and prostanoid profiles in bronchoalveolar lavages (BAL) obtained five hours after methacholine challenge to control lavages without prior challenge. Eight subjects with asymptomatic to mild bronchial asthma and nine nonatopic healthy controls were enrolled in the study. Without prior challenge, the percentage of BAL eosinophils was higher in the asthmatic subjects ((mean +/- SD), 1.1 +/- 0.9%) than in the control subjects (0.1 +/- 0.1%. Leukotriene B4 (LTB4), and its omega-oxidation products (20-OH-LTB4 and 20-COOH-LTB4) were the only leukotrienes detectable in the baseline BAL fluids in five of the eight asthmatic patients. After methacholine challenge, no change in BAL cell profile occurred, but in the asthmatic patients, the total amounts of LTB4 and its omega-oxidation products rose from 0.52 +/- 0.50 ng.ml-1 (pre-challenge) to 1.55 +/- 1.32 ng.ml-1 (post-challenge), and prostaglandin D2 (PGD2) rose from 49.1 +/- 15.7 (pre-challenge) to 94.4 +/- 25.4 pg.ml-1 (post-challenge), with no change in 6-keto-PGF1 alpha, thromboxane B2 (TXB2), and prostaglandins F2 alpha and E2 (PGF2 alpha and PGE2). In the healthy controls, no consistent change in BAL cell profile and mediators occurred after methacholine provocation. We conclude that inhaled methacholine stimulates LTB4 and PGD2 release in asthmatics, but not in healthy controls, without affecting the number of inflammatory cells in BAL fluid.

Topics: Adult; Asthma; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchoscopy; Eosinophils; Female; Humans; Leukocyte Count; Leukotriene B4; Male; Methacholine Chloride; Prostaglandin D2; Time Factors

Alveolar macrophages (AM) may take part in the amplification of the inflammatory mechanism involved in asthma. During an asthma attack, mast cells and eosinophils release arachidonic acid derivative mediators of inflammation such as sulfidopeptide leukotrienes. Among them, LTC4 has been shown to be present in bronchoalveolar fluid. In asthmatic patients, we showed that the ability of AM to transform LTC4 into its derivatives LTD4 and LTE4 was related to the intensity of the local inflammation observed during endoscopy. AM from asthmatics incubated in the presence of LTC4 or LTE4, generated LTB4 and 5-HETE, which are potent chemoattractants. Nedocromil sodium (10(-4) M) decreased LTB4 releasability and intracellular 5-HETE concentrations in zymosan-stimulated AM from asthmatic patients, and was shown to decrease the LTC4 or LTE4-promoted formation of LTB4 and 5-HETE.

Topics: Adolescent; Adult; Aged; Anti-Inflammatory Agents, Non-Steroidal; Asthma; Bronchoalveolar Lavage Fluid; Cells, Cultured; Chromatography, High Pressure Liquid; Female; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Leukotriene E4; Leukotrienes; Macrophages, Alveolar; Male; Middle Aged; Nedocromil; Quinolones; Spectrophotometry, Ultraviolet; SRS-A; Stimulation, Chemical

In this study, it was presented that PAF and LTB4 exert a priming effect on PMNs to promote their superoxide anion production. PMNs preincubated with PAF of normal controls or PMNs from asthmatic patients are activated and their responsiveness to inhibitory stimuli such as antiallergic drugs and corticosteroid are attenuated. In conclusions, inflammatory cells of asthmatics may be activated by various mediators and play an important role in the progress of airway damage.

Topics: Adult; Aged; Asthma; Bronchial Hyperreactivity; Cells, Cultured; Dexamethasone; Female; Humans; Leukotriene B4; Lymphocyte Activation; Macrophage Activation; Macrophages, Alveolar; Male; Middle Aged; Neutrophils; Phthalazines; Platelet Activating Factor; Superoxides

WY-50,295 tromethamine demonstrates significant 5-lipoxygenase inhibitory activity with IC50 values ranging from 0.055 microM in rat peritoneal exudate cells, to 0.16 microM in mouse macrophages, 1.2 microM in human peripheral neutrophils and 8.1 microM in rat blood leukocytes. This activity appeared selective for 5-lipoxygenase as concentrations up to 10 microM in rat peritoneal exudate cells, and 1 microM in mouse macrophages did not effect prostaglandin generation. In non-cellular enzyme assays, WY-50,295 tromethamine displayed inhibitory activity against a soluble 5-lipoxygenase from guinea pig peritoneal exudate cells (IC50 = 5.7 microM), while it was essentially inactive against 12-lipoxygenase, 15-lipoxygenase, or prostaglandin H synthetase at concentrations up to 500 microM, or against human phospholipase A2 at concentrations up to 50 microM. In purified human blood neutrophils the inhibitory activity was reversible but did not appear dependent upon substrate concentration. IN contrast, in the guinea pig cell-free 5-lipoxygenase assay changing the arachidonic acid substrate concentration from 5 to 500 microM produced a concentration-dependent reduction in inhibitory activity. WY-50,295 tromethamine inhibited the release of peptidoleukotrienes from fragmented guinea pig lung with an IC50 of 0.63 microM. When administered p.o. with a 4 h pretreatment time, WY-50,295 tromethamine inhibited ex vivo leukotriene B4 production in rat blood leukocytes with an ED50 of 19.6 mg/kg. Against an ovalbumin-induced leukotriene dependent bronchoconstriction in anesthetized sensitized guinea pigs, WY-50,295 tromethamine inhibited the ovalbumin-induced bronchoconstriction with an i.v. ED50 of 2.5 mg/kg (5 min pretreatment) and a p.o. ED50 of 7.3 mg/kg (4 h pretreatment). Significant activity was also evident with an 18 h pretreatment. Thus WY-50,295 tromethamine is an potent and selective 5-lipoxygenase inhibitor in a number of in vitro systems. Additionally the compound is orally efficacious and has a long duration of action in an allergic bronchoconstriction model. This data suggests that WY-50,295 tromethamine may have utility in the treatment of asthma and other leukotriene-dependent pathologies.

Topics: Administration, Oral; Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Asthma; Female; Guinea Pigs; Humans; Hydroxyurea; Indoles; Leukocytes; Leukotriene B4; Lipoxygenase Inhibitors; Macrophages; Male; Mice; Naphthaleneacetic Acids; Prostaglandin-Endoperoxide Synthases; Quinolines; Rabbits; Rats; Rats, Wistar

We have attempted to determine whether interleukin-5 (IL-5), a cytokine that selectively affects eosinophil (as opposed to neutrophil) differentiation and activation, also modulates eosinophil migrational responses. Using a modified Boyden chemotaxis assay, IL-5, IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF) gave a weak locomotory response for eosinophils from normal nonatopic subjects (optimal at 10(-11), 10(-8), and 10(-9) mol/L, respectively), but not for eosinophils from subjects with an eosinophilia associated with asthma and/or allergic rhinitis. In contrast, IL-5 and IL-3 had no effect on neutrophils, while GM-CSF was chemotactic for neutrophils over a limited concentration range, optimal at 10(-8) mol/L. When eosinophils from normal subjects were incubated with IL-5 (10(-9) mol/L), the locomotory response to platelet-activating factor (PAF; 10(-8) mol/L, P less than .05), leukotriene B4 (LTB4; 10(-6) mol/L, P less than .01), and N-formyl-methionyl-leucyl-phenylalanine (FMLP; 10(-8) mol/L, P less than .01) was significantly enhanced. The percentage enhancement of eosinophil locomotion by IL-5 was greater for eosinophils from normal as compared with subjects with an eosinophilia associated with asthma (P less than .05 for PAF and LTB4; P less than .01 for FMLP). Preincubation of eosinophils from normal subjects with IL-5 (10(-9) mol/L) attenuated the subsequent locomotory response to IL-5 (10(-12) and 10(-11) mol/L, P less than .05). Therefore, the observed refractoriness of eosinophils from eosinophilic subjects to both directional migratory and priming effects of IL-5 in vitro, may reflect a deactivation process resulting from prior exposure in vivo. The selective priming of eosinophil but not neutrophil locomotion by IL-5 suggests that this cytokine may play a significant role in the preferential accumulation of eosinophils at sites of allergic inflammation.

Topics: Asthma; Chemotaxis, Leukocyte; Eosinophilia; Eosinophils; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Interleukin-3; Interleukin-5; Leukotriene B4; N-Formylmethionine Leucyl-Phenylalanine; Platelet Activating Factor; Rhinitis

Among the cells which participate in amplification of the local inflammatory reaction in asthma, neutrophils (PMN) are pro-inflammatory cells that can generate inflammatory mediators and arachidonic acid derivatives in particular. In asthmatic patients (AP) with attacks, the capacity of blood PMN to produce 5-lipoxygenase metabolites was investigated and compared to the response in healthy subjects (HS). PMN from 6 AP and from 6 HS were stimulated by calcium ionophore A23187 and arachidonate 5-lipoxygenase metabolites were analyzed by reverse-phase HPLC. LTB4, 6-trans LTB4, omega OH-LTB4 and 5-HETE were identified. In AP, total LTB4 synthesis was enhanced as compared to synthesis with PMN in HS. But the total 5-HETE synthesis by PMN from AP was decreased. Thus, the inflammatory potential of PMN from AP was enhanced in comparison to HS. The anti-inflammatory effect of nedocromil sodium (NS) was studied in the 5-lipoxygenase metabolism of arachidonic acid. NS (10(-4) mol/l) inhibited total LTB4 synthesized by PMN in AP but not in HS. We conclude that NS affects leukotriene synthesis only in cells with enhanced inflammatory potential.

Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Arachidonate 5-Lipoxygenase; Asthma; Calcimycin; Chromatography, High Pressure Liquid; Humans; Hydroxyeicosatetraenoic Acids; In Vitro Techniques; Leukotriene B4; Male; Middle Aged; Nedocromil; Neutrophils; Quinolones

In order to investigate the possible contribution of leukotrienes to the airway hypersensitiveness and inducibility of asthmatic spells, the probable temporal correlation of the urinary leukotriene levels (U-LTB4 and U-LTC4) were estimated along with the peripheral neutrophil counts in two groups of asthmatic children with or without an inflammatory sign of the elevated CRP. The first group consisted of 6 asthmatic children possessing inflammatory signs and symptoms of fever and peripheral leukocytosis. They all were hospitalized. The second group of 6 patients of light asthmatic attack without any signs and symptoms of acute inflammation were studied in the Outpatient Department. In the first group, U-LTB4 was as high as 258.6 +/- 88.9 ng/mmol Cr. during the attacks while U-LTB4 levels of the second group was as low as 62.2 +/- 32.20 ng/mmol Cr. The difference was statistically significant at p less than 0.01. Further mathematical analysis revealed a positive correlation of U-LTB4 to the peripheral neutrophils counts at r = 0.71. Thus, it was concluded that the elevation of U-LTB4 levels in the first group was strongly related to infections, and their asthmatic spells were thought to represent an infection-induced type. On the contrary, U-LTC4 levels in the samples during the asthmatic attacks were increased in 2 of the 6 of the first group. They both represented grave asthmatic spells. In the remainder, U-LTC4 levels did not rise enough to induce spasmodic contractions of the bronchial smooth muscles. Thus, it was also discussed that the most appropriate timing for urine collection for the study of U-LTs is some time following an asthmatic attack.

Topics: Age Factors; Asthma; Bronchial Hyperreactivity; Child; Child, Preschool; Female; Humans; Infant; Leukocyte Count; Leukotriene B4; Male; Neutrophils; SRS-A

Aspirin and nonsteroidal antiinflammatory drugs induce bronchospastic reactions in patients with aspirin-sensitive respiratory disease. Although the mechanism of this reaction is unknown, all drugs that induce the respiratory reaction also inhibit the cyclooxygenase enzyme. The ensuing changes in arachidonate metabolism are presumed to play a role in the pathogenesis of the reaction. We measured generation of leukotrienes and thromboxane by calcium ionophore stimulated blood monocytes. Before aspirin challenge, monocytes released significantly more thromboxane B2 in patients with aspirin sensitivity than in patients without aspirin sensitivity or in healthy control subjects (p < 0.02). During aspirin-induced bronchospasm, release of leukotriene B4 increased significantly (45.5%, p = 0.018), whereas release of thromboxane B2 decreased (-46.9%, p = 0.028). Two hours after ingestion of 60 mg aspirin, normal monocyte release of thromboxane B2 did not drop, whereas leukotriene B4 release increased. Monocytes formed only minimal amounts of leukotriene C4. We conclude that the profile of released eicosanoids from aspirin-sensitive monocytes is distinct from non-aspirin-sensitive subjects, and that these differences could contribute to the development of bronchospasm after aspirin ingestion.

Topics: Administration, Oral; Adult; Arachidonic Acid; Aspirin; Asthma; Bronchial Spasm; Calcimycin; Eicosanoids; Female; Humans; Leukotriene B4; Male; Middle Aged; Monocytes; Thromboxane B2

Leukotrienes are thought to be involved in allergen-induced airway responses. To test this hypothesis we used a newly described 5-lipoxygenase inhibitor, zileuton, and examined its effect on antigen-induced early and late bronchial responses, airway inflammation and airway hyperresponsiveness in allergic sheep. Early and late responses were determined by measuring specific lung resistance (SRL) before and serially for 8 h after antigen challenge. Airway inflammation was assessed by bronchoalveolar lavage performed before, 8 h after and 24 h after antigen challenge. Airway responsiveness was measured before and 24 h after challenge by determining the dose of inhaled carbachol that caused a 400% increase in SRL (PD400%). The sheep (n = 8) were challenged with Ascaris suum antigen once after vehicle treatment (methylcellulose) and once after treatment with zileuton (10 mg/kg in methylcellulose, p.o.) given 2 h before antigen challenge. Trials were separated by at least 21 days. Zileuton had no effect on the early bronchoconstrictor response to antigen but the drug inhibited the late bronchial response by 55% (P less than 0.05). Unlike the control trial, there was no significant increase in bronchoalveolar lavage eosinophils at 8 h post challenge in the zileuton-treated sheep. Furthermore, zileuton treatment blocked (P less than 0.05) the airway hyperresponsiveness seen 24 h after challenge. Ex vivo formation of leukotriene B4 was inhibited over several hours after a single oral dose of zileuton, indicating that the compound was acting as a 5-lipoxygenase inhibitor in vivo. These results suggest that 5-lipoxygenase metabolites contribute to allergen-induced late responses, airway inflammation and airway hyperresponsiveness in this animal model of asthma.

Topics: Administration, Oral; Animals; Antigens; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Bronchoconstriction; Calcimycin; Dose-Response Relationship, Drug; Hydroxyurea; Leukotriene B4; Lipoxygenase Inhibitors; Sheep

Pathophysiological changes in the airways with aging were examined in 78 patients with bronchial asthma. The FEV1.0% values in patients over the age of 71, and the %MMF, %V50 and %V25 values in those over 51 were significantly lower than those of patients between the ages of 10 and 30. The frequency of lymphocytes in bronchoalveolar lavage (BAL) fluid was significantly higher in patients aged between 61 and 70 than in those aged between 41 and 50 (p < 0.05). The frequency of each clinical asthma type changed with aging; the number of patients with simple bronchoconstriction type (type Ia) decreased with increasing age in patients under the age of 60, and the number of those with bronchiolar obstruction type (type II) increased with aging. The frequency of patients with bronchoconstriction+hypersecretion type (type Ib) showed a peak between the ages of 51 and 60. Bronchial reactivity to methacholine showed a tendency to decrease with aging. The release of histamine from leucocytes induced by Ca ionophore A23187 was significantly higher in patients between the ages of 10 and 30 than in those between the ages of 51 and 60 (p < 0.05) and between 61 and 70 (p < 0.01).

Topics: Adolescent; Adult; Aged; Aging; Airway Resistance; Asthma; Bronchoalveolar Lavage Fluid; Female; Humans; Immunoglobulin E; Leukotriene B4; Male; Middle Aged; Radioallergosorbent Test; Respiration; SRS-A

Leukotriene B4 levels were measured after stimulation by calcium ionophore A23187: (i) in peripheral, neutrophils (PMN) from allergic asthmatics, rhinitis and healthy subjects; (ii) in macrophages collected by bronchoalveolar lavage. LTB4 levels in PMNs were significantly higher in non-treated allergic asthmatics and non-treated subjects with rhinitis compared to controls. Beta-2 agonist-treated asthmatics showed a significantly decreased LTB4 production which was not different from those of controls. In vitro, LTB4 production decreased significantly after PMN incubation with Salbutamol (10(-6) mol l-1). LTB4 produced by AM collected by BAL was measured in non-treated (n = 5) and treated (n = 11) asthmatics with inhaled beta-2 agonist. AM collected from all controls and non-treated asthmatics produced LTB4. By contrast, no production of LTB4 was observed in the treated group. LTB4 production decreased when normal AM were incubated in vitro with Salbutamol (10(-8) mol l-1). These results suggest that biochemical differences occur in PMN and macrophages from subjects treated with beta-2 agonist, presumably in changing the 5-lipoxygenase pathway.

Topics: Adult; Albuterol; Asthma; Calcimycin; Female; Humans; In Vitro Techniques; Leukotriene B4; Macrophages, Alveolar; Male; Neutrophils

Human alveolar macrophages (AM) from bronchoalveolar lavage of asthmatic patients (AP) and healthy volunteers (HS) were compared for their respective capacities to produce lipoxins and leukotrienes when stimulated by calcium ionophore A23187 with or without 15(S)-HETE. The metabolites were analyzed using an isocratic RP-HPLC system and their formation profiles evaluated on the basis of chromatographic behaviour, UV spectral characteristics and co-elution with synthetic standards. Without 15-HETE, AM from AP produced more LTB4 and 5-HETE than those from HS. In the presence of 15-HETE, human AM were able to produce 5,15-diHETE and lipoxins. Moreover, the total amount of lipoxins synthesized by AM from AP was 2 fold higher than that synthesized by AM from HS, thus showing an enhanced cell activation via the 5-lipoxygenase (5-LO) pathway. These results presented AM as in vitro 15-HETE metabolizing cells and suggested some hypothesis about human AM 5-LO regulation mechanism. The enhanced 5-LO activity in AM from AP suggested that in vivo they could participate in cell to cell interaction mechanisms involved in inflammatory lung diseases and might also take up and transform 15-HETE predominantly released by airway epithelial cells.

Topics: Adult; Asthma; Bronchoalveolar Lavage Fluid; Calcimycin; Cells, Cultured; Chromatography, High Pressure Liquid; Epithelial Cells; Epithelium; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Lipoxins; Lung; Macrophage Activation; Macrophages, Alveolar; Middle Aged

To evaluate the acute effects of anti-asthmatic drugs in vitro, we examined the modulation of various anti-asthmatic drugs in therapeutic concentrations on PAF-induced human eosinophil chemotaxis. Aminophylline (20 micrograms/ml) and Isoproterenol (10 nM) inhibited PAF (3 X 10(-8) M)-induced eosinophil chemotaxis nearly 30%, whereas no inhibitory effects were observed by Dexamethasone (0.1 microM), Tranilast, Ketotifen or Azelastine. Aminophylline (20 micrograms/ml) also inhibited LTB4 (3 X 10(-8) M)-induced eosinophil chemotaxis nearly 30%, whereas it did not inhibit chemotaxis induced by zymosan (5 mg/ml)-activated serum. These results indicate that anti-asthmatic drugs except for aminophylline and isoproterenol, when used acutely in therapeutic concentrations, have no striking inhibitory effects on PAF-induced eosinophil chemotaxis. These results further suggest the possibility that there are different mechanisms in eosinophil chemotaxis induced by PAF, LTB4 or by C5a.

Topics: Aminophylline; Asthma; Cells, Cultured; Chemotaxis, Leukocyte; Dexamethasone; Eosinophils; Humans; Isoproterenol; Leukotriene B4; Platelet Activating Factor

A study was made of the effect of ketotifen on the concentration of leukotriene B4, prostacyclin and thromboxane A2 in the liquid of bronchoalveolar lavage and on external respiration and cellular immunity during 4 weeks of the treatment of patients with infection-dependent bronchial asthma and chronic obstructive bronchitis. Inclusion of ketotifen into the treatment of patients with bronchial obstruction exerts a stimulating action on the suppressor component of T-cell immunity, leads to a decrease of the content of leukotriene B4 and thromboxane A2 in the lavage liquid, which is accompanied by positive shifts in the clinical course of the broncho-obstructive syndrome. Ketotifen turned out most effective in patients with an initially low content of the subpopulation of T suppressors and with high concentrations of leukotriene B4 and thromboxane A2 in the liquid of bronchoalveolar lavage.

Topics: Adult; Asthma; Bronchi; Bronchitis; Bronchoalveolar Lavage Fluid; Chronic Disease; Eicosanoids; Epoprostenol; Female; Humans; Ketotifen; Leukotriene B4; Male; Middle Aged; Thromboxane A2

1. The capacity of various drugs (acetylsalicylic acid (ASA), ketoprofen, diclofenac, piroxicam, BW 755C, BW A4C, nedocromil sodium and azelastine) to inhibit human polymorphonuclear neutrophil (PMN)-mediated platelet activation was investigated. In this model, stimulated PMN release cathepsin G (Cat G), a serine proteinase which, in turn, induces platelet activation. 2. Among the different tested drugs, azelastine (100 microM for 1 min) was the only one able to prevent platelet aggregation. The cyclo-oxygenase inhibitors were all inactive, although used at effective concentrations as judged by inhibition of thromboxane B2 (TxB2) formation. Inhibition of platelet aggregation by azelastine was concentration-dependent, the range of active concentrations being of 20-70 microM. Release from platelets of 5-hydroxytryptamine was also inhibited at 30 microM and above, but never reached 100%. 3. The inhibition by azelastine is due to an effect on both cells. Indeed, beta-glucuronidase release from activated PMN and platelet activation by purified Cat G were both affected. 4. However, used at high concentrations (greater than 100 microM) azelastine was toxic since it released significant amounts of lactate dehydrogenase (LDH) from PMN and platelets. 5. These results show the capacity of azelastine, an anti-allergic and anti-asthmatic compound, to inhibit the cell-to-cell communication between PMN and platelets, an effect which may be relevant for its therapeutic efficacy or for a new application in diseases in which PMN and platelets are involved.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Asthma; Glucuronidase; Humans; In Vitro Techniques; L-Lactate Dehydrogenase; Leukotriene B4; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Phthalazines; Platelet Activation; Platelet Aggregation; Platelet Aggregation Inhibitors; Serotonin; Thromboxane B2; Vasodilator Agents

In eight subjects who showed dual asthmatic response (DAR) in bronchial provocation tests (BPT) with specific allergens, local allergen challenge (LAC) was conducted using a flexible bronchofiberscope. We examined the concentrations of histamine, leukotriene B4 and C4 (LTB4 and LTC4) and cell populations in bronchoalveolar lavage fluid (BALF) collected before LAC (control), during the immediate response phase (IR), and the late response phase (LR). Control BALF was collected from the left lingula (B4 or B5), and BALF in the IR or LR phase from the right middle lobe (B4 or B5). Each BAL was conducted with 50 ml of saline at 37 degrees C and repeated three times in succession. It was noted that histamine increased significantly (p less than 0.05) in IR-BALF from the control level. In addition, the concentrations of LTC4 and the numbers of eosinophils increased in IR-BALF. In LR-BALF, the numbers of eosinophils (p less than 0.01), and the concentrations of histamine (p less than 0.05), LTC4 (p less than 0.05) and LTB4 increased. From these results, it was suggested that infiltration of eosinophils and various chemical mediators in the bronchial mucosa play important roles in the development of late asthmatic response.

Topics: Adolescent; Adult; Allergens; Asthma; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Eosinophils; Female; Histamine; Humans; Leukocyte Count; Leukotriene B4; Male; SRS-A

A "late phase" antigen-induced bronchoalveolar eosinophilia has been demonstrated in ovalbumin sensitized guinea pigs (1,2). This in vivo response to antigen inhalation can be inhibited by a 2,6-disubstituted pyridine analog of LTB4, U-75,302(2) (3). In the present study, the mechanism of the drug action was studied by assessing the activity of U-75,302 and a second analog, U-75,485 to displace [3H]-leukotriene B4 binding at the guinea pig eosinophil membrane, as well as their action as chemoattractants or inhibitors of the directional migration of guinea pig eosinophils in vitro. Radioligand competition experiments demonstrated that both analogs interacted strongly with the high affinity LTB4 binding sites on guinea pig eosinophil membrane. Both analogs are powerful chemoattractants for guinea pig eosinophils since they induced directional migration of guinea pig eosinophils when administered alone. In addition, when the cells were treated with either analog and their chemotaxis response was measured in response to a natural chemoattractant, both U-75,302 and U-75,485 at concentrations of 0.1 to 100 microM dose dependently inhibited the LTB4 induced chemotaxis response. The EC50s obtained for U-75,302 and U-75,485 as inhibitors of LTB4 induced guinea pig eosinophil chemotaxis were estimated to be 11.5 +/- 5.5 microM and 5.4 +/- 2.5 microM respectively. Under the same conditions, they had no significant effect upon eosinophil migration induced by zymosan activated plasma at concentrations below 100 microM. We suggest that the inhibition of antigen-induced eosinophil infiltration in guinea pig airway in vivo by U-75,302 or U-75,485 may be a result of partial antagonism or desensitization at the LTB4 receptor level of guinea pig eosinophils.

Topics: Animals; Asthma; Binding, Competitive; Cell Movement; Chemotactic Factors; Dose-Response Relationship, Drug; Eosinophils; Fatty Alcohols; Female; Glycols; Guinea Pigs; Leukotriene B4; Pyridines; Receptors, Immunologic; Receptors, Leukotriene B4

Cytokines from asthmatic mononuclear cells (MNC) cultured with Bermuda Grass pollen extract (BG), were tested for their effect on leukotriene B4 (LTB4) and platelet-activating factor (PAF) generation by neutrophil under calcium ionophore stimulation. Three groups were enrolled in this study: 9 allergic asthmatics showing skin intradermal test positive to BG, 12 non-allergic asthmatics and 5 normal individuals. Results showed that the stimulation index of BG on MNC and the mediator-release enhancing activity from both allergic and non-allergic asthmatics were similar; neither showed significant increase when compared to that of normal individuals. However, there was a significant increase in PAF-release-enhancing activity in unstimulated MNC supernatant from both allergic and non-allergic asthmatics (618 +/- 75 pg/10(6) neutrophils and 569 +/- 60 pg/10(6) neutrophils) when compared to that of normal individuals (460 +/- 40 pg/10(6) neutrophils). This PAF-release-enhancing activity did not correlate with either skin test reactivity or the amount of BG specific IgE antibodies. The PAF-release-enhancing activity in unstimulated MNC supernatants from asthmatics suggesting that there is a pre-activation of MNC which might contribute to the asthmatic reaction through generation of PAF by neutrophils.

Topics: Asthma; Cells, Cultured; Culture Media; Humans; Hypersensitivity, Immediate; Leukocytes, Mononuclear; Leukotriene B4; Lymphocyte Activation; Neutrophils; Platelet Activating Factor; Pollen

Leukotriene B4 has been found to be increased in the serum of cigarette smokers and some patients with bronchial asthma, as well as in the sputum of patients with cystic fibrosis and COPD. Corticosteroids supposedly may block the formation of LTB4. To determine if the effect of CS on airway disease is by reduction in LTB4, we studied serum LTB4 levels in clinically stable patients with asthma or COPD who were treated with or without CS. The LTB4 was extracted from serum and assayed by radioimmunoassay. Serum LTB4 concentrations, expressed as the mean +/- SD, were 0.36 +/- 0.15 ng/ml in ten normal controls, 0.56 +/- 0.18 ng/ml in nine asthmatic subjects, 0.67 +/- 0.2 ng/ml in eight asthmatic subjects receiving CS, 0.81 +/- 0.19 ng/ml in seven patients with COPD, and 0.97 +/- 0.29 ng/ml in eight patients with COPD receiving CS. Serum LTB4 levels in normal controls differed significantly from all groups with COPD or asthma (p less than 0.01). Levels of LTB4 in asthmatic subjects differed from levels in patients with COPD (p less than 0.03), and levels in asthmatic subjects receiving CS differed from subjects with COPD receiving CS (p less than 0.03). Concentrations of LTB4 within either the COPD or the asthmatic groups were not lower in the patients treated with CS. We conclude that serum LTB4 concentrations are higher in COPD than in asthma or normal controls and that administration of CS is not associated with low LTB4 levels. The beneficial effects of CS in obstructive airway disease appear to be mediated by mechanisms other than reduction of LTB4.

Topics: Adult; Aged; Asthma; Forced Expiratory Volume; Humans; Leukotriene B4; Lung Diseases, Obstructive; Middle Aged; Prednisone; Smoking

The mechanism involved in amplification of the local inflammatory process, characteristic of asthma, was investigated through the role of human alveolar macrophages. During asthma attacks, mast cells and eosinophils are known to be activated in order to release arachidonic acid derived inflammation mediators such as sulfidopeptide leukotrienes. It is now known that these metabolites, particularly leukotriene C4, are present in bronchoalveolar lavage from asthmatic patients. Alveolar macrophages, recovered by bronchoalveolar lavage and purified by adherence, are able to transform LTC4 into LTE4. In four asthmatic patients with severe local inflammation as determined by fibrobronchoscopy, these phagocytes, incubated in the presence of LTC4, also generated LTB4 and 5-HETE, which remained within the cells. These preliminary results are discussed relative to amplification of the local process, involving cooperation between the different cells involved in airway responsiveness.

Topics: Adult; Asthma; Humans; Hydroxyeicosatetraenoic Acids; In Vitro Techniques; Leukotriene B4; Leukotrienes; Macrophage Activation; Macrophages; Pulmonary Alveoli; SRS-A

The generation and metabolism of leukotrienes (LTs) B4, C4, D4, and E4 were studied in vitro in the A23187-stimulated whole blood of normal (N) and atopic asthmatic (AA) human subjects. Using a combination of reversed-phase high performance liquid chromatography and radioimmunoassay, we have demonstrated that the blood cells of atopic asthmatic patients have an enhanced ability to release LTB4 and LTC4 when compared to those of normal subjects. The release of LTB4 and LTC4 in response to ionophore is dose- and time-dependent. Half-maximal doses of ionophore caused the generation of high, sustained levels of LTB4, which are significantly higher in the AA blood than in N blood. Incubations of 3H-LTB4 in ionophore-stimulated N and AA blood revealed a slow metabolism to 20-OH-LTB4 and 20-COOH-LTB4. LTC4 is generated in smaller amounts than LTB4, with an early peak after 10 min which is significantly higher (p less than 0.01) in the AA blood compared to the N blood. Subsequent metabolism of LTC4 elicits significantly greater amounts of LTD4, and consistently higher levels of LTE4, in the AA blood. Parallel incubations of 3H-LTC4 in ionophore-stimulated N and AA blood demonstrated rapid metabolism of LTC4 by the glutathione detoxification pathway. The elevated production of LTB4 and LTC4 in AA blood was not accounted for by differences in leukocyte sub-type counts in the two groups, nor by differences in their rates of catabolism. The novel, selective 5-lipoxygenase inhibitor BW A4C [N-(3-phenoxycinnamyl) acetohydroxamic acid] caused dose-dependent inhibition of LTB4 and LTC4 generation and was equipotent in N and AA blood.

Topics: Asthma; Benzeneacetamides; Calcimycin; Chromatography, High Pressure Liquid; Female; Humans; Hydroxamic Acids; In Vitro Techniques; Leukocyte Count; Leukotriene B4; Leukotrienes; Lipoxygenase Inhibitors; Male; Radioimmunoassay; Reference Values

Production of LTC4 and LTB4 by eosinophils and neutrophils was compared between nine asymptomatic asthmatic subjects and eight healthy donors. We observed a statistically significant difference in LTC4 generated by eosinophils, but not LTB4 produced by neutrophils. These findings suggest a quantitative difference in eosinophils between asthmatic subjects and healthy donors.

Topics: Asthma; Cells, Cultured; Chromatography; Eosinophils; Humans; Leukotriene B4; Neutrophils; Reference Values; SRS-A

We investigated whether leukotriene B4 (LTB4) is released from the lungs of sensitized subjects during asthmatic reactions induced by toluene diisocyanate (TDI). We examined three groups of TDI-sensitized subjects, one after no exposure to TDI, the second 8 h after an exposure to TDI that caused an early asthmatic reaction, and the third 8 h after an exposure to TDI that caused a late asthmatic reaction. We analyzed bronchoalveolar lavage (BAL) fluid by reverse-phase high-performance liquid chromatography and by specific radioimmunoassay. The mean concentration of LTB4 was higher [0.31 +/- 0.09 (SE) ng/ml, range 0.15-0.51] in BAL fluid of sensitized subjects who developed a late asthmatic reaction than in BAL fluid of subjects who developed an early asthmatic reaction (0.05 +/- 0.04 ng/ml, range 0-0.224), and no LTB4 was detectable in the control subjects. We also performed BAL 8 h after TDI exposure on four TDI-sensitized late-dual reactors who were on steroid treatment. In this group of subjects no LTB4 was detectable. These results suggest that LTB4 may be involved in late asthmatic reactions induced by TDI.

Topics: Adult; Asthma; Bronchoalveolar Lavage Fluid; Chromatography, High Pressure Liquid; Cyanates; Female; Humans; Leukocyte Count; Leukotriene B4; Male; Neutrophils; Toluene 2,4-Diisocyanate

To investigate whether leukotriene B4 is present in the arterial blood of asthmatic patients during wheezing attacks, 20 ml of arterial blood was drawn from the inguinal artery of five patients. Leukotriene B4 was detected in all five individuals, and its identity was confirmed by a combination of high pressure liquid chromatography and radioimmunoassay techniques. The concentration of leukotriene B4 was 48.34 +/- 16.27 pg ml-1 (mean value +/- SE). However, in five control subjects the leukotriene B4 concentration was found to be 9.43 +/- 5.44 pg ml-1. Thus there was a significant difference between the two groups (P less than 0.05). These results suggest that leukotriene B4 may be important in elucidation of the pathogenesis of bronchial asthma.

Topics: Adult; Asthma; Chromatography, High Pressure Liquid; Female; Humans; Leukotriene B4; Male; Radioimmunoassay; Respiratory Sounds

We determined the relationship of allergic disease to the number and activity of eosinophils and their production of leukotriene B4 and leukotriene C4 (leukotriene D4 equivalents). Granulocytes from allergic rhinitis (AR) subjects and asthmatics release more LTC4 than normals. Furthermore, eosinophils of asthmatics generate more LTC4 than those of AR subjects.

Topics: Adult; Asthma; Calcimycin; Eosinophils; Female; Granulocytes; Humans; Leukocyte Count; Leukotriene B4; Male; Middle Aged; Reference Values; Rhinitis, Allergic, Seasonal; SRS-A; Statistics as Topic

To assess the role of arachidonic acid metabolites in pathogenesis of bronchial asthma, we measured thromboxane B2 (TxB2), 6-keto PGF1 alpha, leukotriene (LT) C4, and LTB4 in venous blood plasma in patients with bronchial asthma and in controls. The level of TxB2 was significantly higher in 18 asthmatics with attacks than that in 11 controls (77.3 +/- 48.8 pg/ml vs 48.8 +/- 9.4 pgml). The levels of 6-keto PGF1 alpha in both asthmatics with attacks (17.8 +/- 6.7 pg/ml) and without an attack (16.4 +/- 9.7) were significantly higher than that in controls (11.6 +/- 3.9 pg/ml). The levels of LTC4 in asthmatics with attacks (0.84 +/- 0.11 ng/ml, n = 11) were significantly higher than that in controls, furthermore the level of LTC4 in asthmatics without an attack. The level of LTB4 was significantly higher in asthmatics with attacks (295.0 +/- 160.7 pg/ml, n = 26) than that in controls (161.7 +/- 25.3 pg/ml, n = 12) and asthmatics without an attack (182.4 +/- 97.9 pg/ml, n = 22). These findings suggest that the arachidonic acid metabolites are related to the asthma attack and are associated with the pathogenesis of bronchial asthma.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Arachidonic Acid; Arachidonic Acids; Asthma; Female; Humans; Leukotriene B4; Male; Middle Aged; SRS-A; Thromboxane B2

Mediator release was examined from superficially lying cells in the airway epithelium obtained by bronchoalveolar lavage (BAL) in 13 non-atopic individuals. The BAL-cells were incubated (20 min, 37 degrees C) with Staphylococcus (Staph.) aureus or with human influenza A virus Staph. aureus was found to release histamine from cells from 7 of the 13 individuals and influenza A virus in 3 of 5 persons. Furthermore, Staph, aureus stimulated the BAL-cells to release leukotriene B4 in 7 of 11 subjects, whereas no release was found by influenza A virus in 7 examined persons. When cells from 4 persons were stimulated with Staph. aureus no release of leukotriene C4 was found. The mediator release caused by bacteria and virus might be of importance for the exacerbation of bronchial asthma in upper respiratory tract infections, since histamine is assumed to increase the epithelial permeability with entrance of allergens and other insulting particles, and leukotriene B4 facilitates airway inflammation.

Topics: Adult; Aged; Asthma; Female; Histamine Release; Humans; In Vitro Techniques; Influenza A virus; Leukotriene B4; Leukotrienes; Male; Middle Aged; Respiratory System; Respiratory Tract Infections; SRS-A; Staphylococcus aureus

Studies have demonstrated that increased amounts of histamine in the airways of asthmatic patients are associated with increased airway reactivity. However, using routine bronchoalveolar lavage (BAL), histamine can be detected in only a portion of asthmatic subjects and a minority of control populations. To obtain relevant mediators from the airways in higher concentrations by avoiding the dilution inherent with a standard BAL, a technique was developed to lavage isolated airway segments of the human lung that employed a double-lumen bronchoscope and a balloon-tipped catheter. Lavage fluid obtained by this method yielded significantly higher concentrations of histamine than that obtained with routine BAL (asthmatic subjects, 2,403 +/- 633 pg/ml vs 188 +/- 42 pg/ml; rhinitis subjects, 533 +/- 187 pg/ml vs 113 +/- 53 pg/ml; normal subjects, 174 +/- 63 pg/ml vs 11 +/- 11 pg/ml). Similar findings were also noted for prostaglandin D2 (PGD2). Segmental airway lavage also resulted in higher lavage fluid concentrations of LTB, than routine BAL. Segmental airway lavage should help in studying the relationship of mast cell degranulation to airways reactivity in both asthmatic and other study populations.

Topics: Adolescent; Adult; Asthma; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchoscopes; Bronchoscopy; Catheterization; Histamine; Humans; Leukotriene B4; Methacholine Chloride; Methacholine Compounds; Middle Aged; Prostaglandin D2; Rhinitis, Allergic, Seasonal; Therapeutic Irrigation

1. Inflammatory cells such as eosinophils and neutrophils are thought to contribute actively to the pathogenesis of asthma by the release of bronchoconstrictor mediators including leukotrienes. Previous studies have revealed the almost exclusive synthesis of leukotriene C4 (LTC4) by human eosinophils and of leukotriene B4 (LTB4), 20-OH-LTB4 and the non-enzymatically formed LTB4-isomers by neutrophils when stimulated in vitro with the calcium ionophore A23187 or opsonized zymosan (OZ). In this study we have investigated whether nedocromil sodium, a new anti-asthma drug, was capable of inhibiting A23187- and OZ-induced leukotriene formation by these cells. 2. Nedocromil sodium inhibited A23187- and OZ-induced LTC4 formation by eosinophils in a concentration-dependent manner (mean IC30 for A23187: 5.6 X 10(-5) M; mean IC30 for OZ: 6.3 X 10(-5) M), whereas it did not inhibit A23187- and OZ-induced LTB4 formation by neutrophils. 3. Extension of the preincubation time of the cells with the drug did not alter the observed inhibitory capacity. The optimal preincubation time was 5 min. 4. The in vitro inhibition of LTC4 formation by eosinophils by nedocromil sodium may be a valuable property of this drug in the treatment of asthma.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Asthma; Calcimycin; Eosinophils; Humans; Hypersensitivity; In Vitro Techniques; Leukotriene B4; Nedocromil; Neutrophils; Quinolones; Zymosan

We have measured the total and differential cell counts, histamine, leukotriene (LT) B4 and LTC4, immunoglobulins, complement (C3), eosinophil-derived basic proteins, and monocyte complement rosettes in bronchoalveolar lavage (BAL) 6 h after challenge with either antigen or diluent control in seven patients with antigen-induced single early reactions, and seven with dual (early and late phase) reactions. In both groups, the total cell counts in BAL were similar, irrespective of whether they were challenged with antigen or diluent. However, in the late-phase responders (LPR), there were significant increases in lymphocytes, neutrophils, and eosinophils (p less than 0.05), and significant decreases in the percentage of lung mast cells (p less than 0.05). The eosinophil major basic protein and eosinophil-derived neurotoxin increased in four of five subjects with dual responses and in the majority of single early responders (SER). BAL histamine concentrations increased in five of seven patients with dual responses. There were no consistent changes in LTB4 concentrations in either the LPR or the SER between diluent and antigen days, but a small but significant increase in LTC4 was observed in the LPR. Concentrations of IgG, IgA, IgM, IgE, C3, and albumin did not differ significantly. The percentage of monocyte complement rosettes also increased significantly (p less than 0.05) in LPR, but not in SER. These findings support the hypothesis that eosinophils and their products play a role in tissue injury in LPR and that eosinophil infiltration may be associated with macrophage activation.

Topics: Adolescent; Adult; Allergens; Asthma; Blood Proteins; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchoscopy; Complement C3; Eosinophil Granule Proteins; Female; Forced Expiratory Volume; Histamine; Humans; Immunoglobulins; Leukocyte Count; Leukotriene B4; Macrophages; Male; Mast Cells; Ribonucleases; SRS-A; Time Factors

Alveolar macrophages (AM) are the principal resident phagocytes in the human lung, and play a major role in local defence against environmental agents. It is now known that during asthma these cells take part in the amplification of the inflammatory mechanism. It has been demonstrated in vitro that they can be activated to generate leukotriene B4 (LTB4) and 5-hydroxyeicosatetraenoic acid (5-HETE), mediators with potent pharmacological properties. These two arachidonic metabolites were identified and quantified by reversed phase high performance liquid chromatography (HPLC) performed in cell suspensions, and in cell free supernatants. AM from asthmatics, after stimulation by the calcium ionophore A23187 or opsonized zymosan, released significantly (p less than 0.05) more LTB4 than those from healthy subjects. The increase in LTB4 release could be evidence for in vivo activation. On the other hand, the levels of 5-HETE in the AM from asthmatics were significantly (p less than 0.03) higher than those in cells from healthy subjects. This intracellular increase could be correlated with a greater migratory ability of these inflammatory macrophages, as observed for eosinophils. The clinical efficacy of nedocromil sodium may be partly related to the decreases in LTB4 releasability and intracellular 5-HETE levels observed only in AM from asthmatic patients.

Topics: Adolescent; Adult; Asthma; Bronchoalveolar Lavage Fluid; Calcimycin; Cells, Cultured; Chromatography, High Pressure Liquid; Female; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Macrophages; Male; Middle Aged; Nedocromil; Pulmonary Alveoli; Quinolones; Zymosan

Airway responsiveness to histamine and leukotriene E4 (LTE4) has been compared between five subjects with aspirin-induced asthma (AIA) and 15 asthmatic subjects without aspirin sensitivity (non-AIA). In the AIA group, the geometric mean doses of histamine and LTE4 causing a 35% fall in specific airway conductance (PD35) were 0.31 mumol and 0.17 nmol, respectively, and LTE4 was 1,870 times more potent than histamine. In the non-AIA group, the histamine and LTE4 PD35 doses were 0.40 mumol (non-AIA versus AIA, NS) and 2.8 nmol (non-AIA versus AIA, p = 0.002), respectively, and LTE4 was 145 times more potent than histamine in eliciting bronchoconstriction (non-AIA versus AIA, p = 0.001). After desensitization to aspirin the geometric mean histamine and LTE4 PD 35 in the AIA group changed to 0.19 mumol (NS) and 3.3 nmol (p = 0.007), respectively, and there was an average 33-fold reduction in the responsiveness of the airways to LTE4 relative to histamine (p less than 0.001). In five non-AIA subjects. Ingestion of 600 mg of aspirin daily did not lead to any significant change in airway responsiveness to histamine or to LTE4. These results demonstrate a selective and marked increase in airway responsiveness to LTE4 in subjects with AIA. The efficacy of desensitization may relate in part to a selective down-regulation of LTE4 receptors within the airways.

Topics: Adult; Aspirin; Asthma; Bronchial Provocation Tests; Female; Histamine; Humans; Leukotriene B4; Male; Middle Aged; Time Factors

Leukotrienes (LTs) C4 and B4 are potent proinflammatory mediators with a wide variety of biologic activities, including smooth muscle contraction, mucus hypersecretion, and leukocyte activation, which may be of particular relevance to the pathology of asthma and other respiratory diseases. We measured the concentrations of LTC4 and LTB4 in bronchoalveolar lavage fluid from 16 atopic subjects with asthma (eight symptomatic and eight asymptomatic) and from 14 control subjects without asthma (six with hay fever and eight nonatopic). The amounts detected in symptomatic subjects with asthma were significantly higher than in control subjects (LTB4, 0.58 +/- 0.06 versus 0.36 +/- 0.05 pmol/ml, p less than 0.05; LTC4, 0.36 +/- 0.1 versus 0.12 +/- 0.02 pmol/ml, p less than 0.01). LTC4 and LTB4 were also measured in 17 patients: nine with interstitial lung disease of varying etiology (cryptogenic fibrosing alveolitis [CFA] or idiopathic pulmonary fibrosis), three with sarcoidosis, one with extrinsic allergic alveolitis, one with sulphonamide-induced pneumonia, and one patient with eosinophilic granuloma. The concentrations of LTB4 (but not LTC4) were significantly greater in patients with CFA compared with normal control subjects (0.69 +/- 0.3 versus 0.36 +/- 0.05 pmol/ml, p less than 0.01). There was a significant correlation (p less than 0.05) between the percentage of neutrophils and the concentration of LTB4 in the bronchoalveolar lavage fluid) of the group with interstitial lung disease as a whole. This study provides evidence for a role for LTs in the airways of subjects with day-to-day asthma and suggests that LTB4 may also be involved in the recruitment of granulocytes into the lung in patients with CFA.

Topics: Adult; Asthma; Bronchoalveolar Lavage Fluid; Cross-Sectional Studies; Female; Humans; Leukotriene B4; Male; Middle Aged; Respiration Disorders; SRS-A

We have developed a new method using a computerized photodiode-array spectrophotometer (CPAS), to characterize the biosynthesis and the inhibition of leukotriene (LT) B4, C4, D4 and E4 in calcium ionophore (Ca-I)-stimulated whole blood. The results obtained were as follows: 1. The use of CPAS enabled us to identify and measure LTs from 2 ml volume of Ca-I stimulated whole blood as well as to check the purity of LTs, without any use of radioimmunoassay or bioassay. 2. LTC4 produced in whole blood was almost completely converted to LTE4 after 80 min incubation, and at this time both the production of LTE4 and LTB4 reached a plateau and remained constant thereafter. 3. Azelastine added in vitro caused a dose-dependent inhibition of Ca-I stimulated LTB4 and LTE4 production with an IC50 of 10 microM.

Topics: Adolescent; Age Factors; Asthma; Calcium-Binding Proteins; Child; Chromatography, High Pressure Liquid; Humans; Leukotriene B4; Monitoring, Physiologic; Phthalazines; Spectrophotometry; SRS-A

Peripheral blood mononuclear cells (PBMC) were isolated from seven normal subjects, eight asthmatic subjects clinically sensitive to corticosteroids (CS), and eight asthmatic subjects clinically resistant to corticosteroids (CR). PBMC were cultured at 37 degrees C for 24 h in the absence or presence of 10(-16) to 10(-4) M hydrocortisone. Calcium ionophore (A23187)-activated neutrophils (PMN) primed by supernatants of PBMC from asthmatic subjects cultured in the absence of hydrocortisone generated approximately threefold more leukotriene B4 than PMN primed by supernatants of PBMC from normal subjects (P less than 0.05). Incubation of PBMC derived from CS subjects with 10(-8) M hydrocortisone completely inhibited the production of the enhancing activity (P less than 0.01), whereas in CR subjects hydrocortisone at concentrations up to 10(-4) M did not suppress the release of enhancing activity. The enhancing activity was produced by monocytes. Enhancing activity eluted with an Mr of 3,000 D and a pI of 7.1. It eluted at 10% acetonitrile after reverse-phase HPLC. The activity was destroyed by heating to 60 degrees C for 60 min and was sensitive to pronase treatment. The purified factor also enhanced superoxide generation by PMN which had been stimulated submaximally by phorbol myristate acetate.

Topics: Adrenal Cortex Hormones; Arachidonic Acid; Arachidonic Acids; Asthma; Calcimycin; Cells, Cultured; Chromatography, High Pressure Liquid; Drug Resistance; Forced Expiratory Volume; Humans; Hydrocortisone; Isoelectric Point; Kinetics; Leukotriene B4; Lipoxygenase; Molecular Weight; Monocytes; Neutrophils; Peptides

The levels of leukotriene C4 (LTC4), leukotriene B4 (LTB4), prostaglandin E2 (PGE2), and histamine were measured in nasal lavage fluids obtained from aspirin-sensitive, desensitized aspirin-sensitive, and aspirin-insensitive asthmatics and normal volunteers before and after ingestion of aspirin. Increased levels of LTC4 and histamine were associated with significant decreases in the FEV1 for 3 of 4 aspirin-sensitive asthmatics who had both naso-ocular and bronchospastic reactions to aspirin. In contrast, no increase in LTC4 or histamine release was detected in aspirin-sensitive asthmatics who had only bronchospastic reactions to aspirin. No significant decreases in PGE2 levels or increases in LTB4 levels were detected during these reactions to relatively low doses of aspirin regardless of the clinical symptoms, nor was any increase in mediator release apparent in lavage fluids from normal donors, aspirin-insensitive asthmatics, and desensitized aspirin-sensitive subjects before or after various doses of aspirin. Levels of PGE2 decreased in nasal secretions from normal volunteers, aspirin-insensitive asthmatics, and desensitized aspirin-sensitive subjects after ingestion of 650 mg of aspirin. These decreases were not associated with increased LTC4 or LTB4 or with histamine release, decreased FEV1, or naso-ocular symptoms. In addition, reductions of PGE2 release were similar for normal and desensitized aspirin-sensitive volunteers (63 +/- 11 versus 61 +/- 10%, respectively). The data demonstrate that LTC4 and histamine are released into nasal secretions of aspirin-sensitive asthmatics with naso-ocular and bronchospastic reactions after ingestion of low doses of aspirin without a decrease in the levels of PGE2 and suggest that LTC4 and histamine contribute to the naso-ocular and bronchospastic symptoms characteristic of reactions to aspirin.

Topics: Adult; Aspirin; Asthma; Dinoprostone; Drug Hypersensitivity; Female; Forced Expiratory Volume; Histamine Release; Humans; Leukotriene B4; Male; Middle Aged; Nasal Mucosa; Prostaglandins E; Reference Values; SRS-A

Ovalbumin (OA) aerosol exposure caused an increase in phospholipase (PLase) activity in guinea pig lung membranes and in leukotriene B4 (LTB4) in lung lavages with subsequent neutrophil influx into lung lavages. These results suggest that activation of PLase after exposure to OA aerosol triggers an increase in LTB4 synthesis resulting in neutrophil influx into the airways.

Topics: Animals; Asthma; Cell Count; Cell Movement; Chemotaxis, Leukocyte; Leukotriene B4; Lung; Membranes; Neutrophils; Phospholipases; Therapeutic Irrigation; Time Factors

1. The chemically novel acetohydroxamic acids, BW A4C, BW A137C and BW A797C, are potent inhibitors of the synthesis of leukotriene B4 (LTB4) from arachidonic acid by human leucocyte homogenates: the concentrations required for 50% inhibition (IC50) were 0.1 microM, 0.8 microM and 0.5 microM respectively. Inhibition was less at higher concentrations of arachidonic acid. 2. These compounds also inhibited the synthesis of [14C]-5-HETE from [14C]-arachidonic acid and the calcium-dependent synthesis of LTB4 from 5-HPETE. This, therefore, suggests that they inhibit 5-lipoxygenase and LTA4 synthase. 3. Concentrations of acetohydroxamic acids required to inhibit metabolism of arachidonic acid by cyclo-oxygenase, 12-lipoxygenase and 15-lipoxygenase were 10 to 100 times higher than those required to inhibit 5-lipoxygenase. 4. The compounds were potent inhibitors of LTB4 synthesis induced by the ionophore, A23187, in human intact leucocytes. This inhibition was reversed by washing the cells. They were also potent, selective inhibitors of LTB4 synthesis induced by A23187 in whole rat blood: binding to rat plasma proteins did not greatly reduce the effectiveness of the compounds. 5. The effects of the acetohydroxamic acids, administered either intravenously or orally to rats, on the synthesis of LTB4, and thromboxane B2 (TXB2) in A23187-stimulated blood ex vivo was studied. The three compounds caused dose-dependent inhibition of the synthesis of LTB4 but not TXB2. Inhibition of LTB4 synthesis persisted for up to 6 h after a single oral dose of 50 mg kg-1. 6. The plasma concentrations of unchanged compound determined by h.p.l.c. correlated with the inhibition of LTB4 synthesis ex vivo.

Topics: Animals; Arachidonate 5-Lipoxygenase; Arachidonate Lipoxygenases; Asthma; Blood Platelets; Carrier Proteins; Chromatography, High Pressure Liquid; Humans; Hydroxamic Acids; In Vitro Techniques; Leukocytes; Leukotriene B4; Lipoxygenase Inhibitors; Male; Rats; Thromboxane B2

The metabolism of exogenous leukotriene B4 (LTB4) was investigated in venous blood obtained from normal and asthmatic subjects. Using specific radioimmunoassay (RIA) and reverse-phase high performance liquid chromatography (RP-HPLC) techniques we have demonstrated that LTB4 is relatively stable during a 2 hr incubation period at 37 degrees C in our system in vitro. Nevertheless, chromatographic analysis revealed the presence of two products which had retention times identical to 20-hydroxy LTB4 (20-0H LTB4) and 20-carboxy LTB4 (20-C00H LTB4) in which the dicarboxylic derivative was the main metabolite present after 15 min incubation. The amount of LTB4 and its w-oxidation products observed after a 2 hr incubation period was 73% and 24% respectively. There was no basal release of LTB4 from blood. The appearance of these oxidative products was totally suppressed at 4 degrees C and with incubations performed with either venous plasma or Hartmann's control. No significant difference was observed in substrate metabolism between normal and asthmatic subjects. Our results demonstrate that LTB4 is slowly degraded in human whole blood through a cellular dependent process of w-oxidation which may be an important pathway for regulating the availability of this potent biologically active substance.

Topics: Asthma; Chromatography, High Pressure Liquid; Humans; In Vitro Techniques; Leukotriene B4; Radioimmunoassay; Scintillation Counting

The generation of LTB4 by peripheral blood neutrophils (PMN) isolated before and for as long as 6 h after exercise-induced asthma (EIA) has been analyzed. Three and 6 h after the development of EIA, PMN isolated from 10 asthmatic subjects and stimulated in vitro by 2 x 10(8) and 4 x 10(8) zymosan particles per 2 x 10(6) PMN demonstrated a 12- and 4-fold enhancement, respectively, in the production of immunoreactive LTB4 as compared with PMN isolated before exercise. At 6 h after EIA, there was a redistribution of generated LTB4 such that 30 to 40% of LTB4 produced by zymosan-activated PMN was released extracellularly as compared with 10% before exercise. There was no significant enhancement in the generation of LTB4 by unstimulated PMN at any time point after exercise. Resolution by reverse-phase high performance liquid chromatography (HPLC) of products from [3H]arachidonic-acid-labeled and zymosan-activated PMN demonstrated that, in addition to LTB4, there was enhanced metabolism to 6-trans-LTB4, omega-oxidation metabolites of LTB4 and 5-HETE. Stimulation of PMN with 10 microM A23187 revealed a 2-, 6-, and 5-fold enhancement in the production of LTB4, 6-trans-LTB4, and 5-HETE, respectively, at 6 h after EIA, as measured by integrated ultraviolet absorbance after HPLC. There was no significant enhancement in LTB4 generation by PMN in 6 asthmatic subjects after methacholine-induced bronchospasm, and after exercise in 6 subjects who did not develop asthma. The augmentation of PMN LTB4 generation in EIA correlated with the extent of the early decrease in SGaw.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; Airway Resistance; Arachidonate 5-Lipoxygenase; Asthma; Asthma, Exercise-Induced; Bronchial Provocation Tests; Calcimycin; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Female; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Male; Methacholine Chloride; Methacholine Compounds; Middle Aged; Neutrophils; Stereoisomerism; Zymosan

Topics: Adult; Asthma; Child; Child, Preschool; Chronic Disease; Humans; Leukotriene B4; Neutrophils

Aspirin (ASA)-induced asthma is a distinct clinical syndrome in which bronchoconstrictive response to nonsteroidal anti-inflammatory drugs can be predicted on the basis of their in vitro activity as inhibitors of cyclooxygenase. In ten ASA-sensitive asthmatics and ten matched healthy controls we measured 12-hydroxy-eicosatetraenoic acid (12-HETE) production by platelets and 5-hydroxy-eicosatetraenoic acid (5-HETE) and leukotriene B4 (LTB4) production by polymorphonuclear leucocytes. The blood cells were obtained before administration of the threshold doses of ASA and during the ASA-induced reactions. Initial levels of eicosanoids determined did not differ between the two groups. In both groups, after ASA challenge, 12-HETE rose to similar levels while 5-HETE and LTB4 remained unchanged. These data do not support the concept that an abnormality in the regulation of arachidonic acid oxidative pathways in ASA-sensitive asthmatics is a generalized phenomenon which embraces the platelets and leucocytes; rather it is inhibition of cyclo-oxygenase within the tissues of the respiratory tract that triggers asthmatic attacks in the sensitive patients.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adult; Arachidonate 12-Lipoxygenase; Arachidonic Acids; Aspirin; Asthma; Blood Platelets; Female; Humans; Hydroxyeicosatetraenoic Acids; Leukocytes; Leukotriene B4; Male; Middle Aged

Topics: Adolescent; Asthma; Asthma, Exercise-Induced; Body Temperature Regulation; Body Water; Child; Female; Histamine; Humans; Leukotriene B4; Male

Topics: Asthma; Calcimycin; Histamine Release; Humans; Hypersensitivity, Immediate; Leukocytes; Leukotriene B4; SRS-A

Purified serum samples from asthmatic and psoriatic patients and healthy controls were analysed by high-pressure liquid chromatography (HPLC) and the amounts of leukotrienes were measured from the corresponding HPLC fractions by specific radioimmunoassays. In the serum of healthy controls the amounts of leukotrienes B4, C4 and D4 were very small or negligible. Rather great amount of leukotriene B4 was, however, detected in the serum of many asthmatic and psoriatic patients. The amount of leukotriene B4 was in the serum of asthmatic patients 120 +/- 20 pmol/ml (n = 11, mean +/- SEM) and in that of psoriatic patients 100 +/- 10 pmol/ml (n = 10). The amounts of leukotrienes C4 and D4 were rather small in the serum of most patients. The amount of leukotriene C4 was, however, very high (250 pmol/ml) in the serum of a psoriatic patient. Significant amount of leukotriene D4 was also detected in the serum of this patient. The present study indicated that leukotrienes are formed during blood clotting in the leukocytes of asthmatic and psoriatic patients and that the rate of formation is so high that leukotrienes may have a role in these diseases.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adolescent; Adult; Aged; Asthma; Chromatography, High Pressure Liquid; Female; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Male; Middle Aged; Psoriasis; SRS-A

Amoxanox has potent antiallergic activity because it inhibits the release of chemical mediators such as histamine and leukotrienes. We studied the in vitro effect of amoxanox on arachidonic acid metabolism, including the lipoxygenase and cyclooxygenase pathways. Amoxanox inhibited calcium ionophore A23187-induced formation of 5-HETE, LTB4, SRS-A (LTC4, LTD4 and LTE4), and 12-HETE in rat peritoneal resident monocytes. These results indicate that amoxanox inhibits 5- and 12-lipoxygenases. The compound, however, did not affect the formation of TXB2 or 6-keto-PGF1 alpha in guinea pig lung fragments and PGE2 or PGF2 alpha in bovine seminal vesicles, suggesting that it did not inhibit cyclooxygenase. These results show that the antiallergic action of amoxanox is associated, at least in part, with the reduction of leukotrienes due to the inhibition of lipoxygenases.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 5,8,11,14-Eicosatetraynoic Acid; Aminopyridines; Animals; Asthma; Calcimycin; Cattle; Guinea Pigs; Histamine H1 Antagonists; Hydroxyeicosatetraenoic Acids; Hypersensitivity; In Vitro Techniques; Leukotriene B4; Lipoxygenase Inhibitors; Lung; Male; Monocytes; Prostaglandins; Rats; Rats, Inbred Strains; SRS-A; Thromboxane B2

Topics: Animals; Asthma; Bronchi; Capillary Permeability; Endothelium; Leukotriene B4; Microcirculation; Molecular Weight; Nervous System Physiological Phenomena; Pulmonary Circulation; Pulmonary Edema; Respiratory Hypersensitivity; SRS-A; Sympathomimetics; Trachea; Venules

The role of lipoxygenase products was studied in children suffering from chronic diseases of the lung. Leukotrienes C4, D4, E4 and B4 were measured by high performance liquid chromatography (HPLC) and a specific radioimmunoassay (RIA) for C4. Elevated levels (up to 40 ng/ml), especially for leukotriene E4, were found in plasma of asthmatic and bronchitic patients (leukotriene C4 concentrations varied between 0.05 and 40 ng/ml, mean 4.9 +/- 7.8 ng/ml). In healthy donors the concentrations were below the detection limits of HPLC, leukotriene C4 ranging between 5 +/- 4 ng/ml (RIA data). The conversion of leukotriene C4 to D4 and E4 was observed by incubating the samples with synthetic leukotriene C4. The half-life of leukotriene C4 in plasma varied greatly, ranging from less than 12 min to 72 min (mean 39 +/- 16 min). Bronchial lavages yielded leukotriene C4 concentrations of 0.2 to 7 ng. Leukotriene E4 was detected in 10 of 41 cases. Conversion of leukotriene C4 did not occur in 50% of all cases, but was regularly observed in putrid lavages. These data suggest that leukotrienes play an important role in allergic and infectious lung diseases.

Topics: Adolescent; Asthma; Bronchitis; Child; Child, Preschool; Chromatography, High Pressure Liquid; Chronic Disease; Humans; Infant; Leukotriene B4; Leukotriene E4; Radioimmunoassay; Respiratory Tract Diseases; SRS-A

The leukotrienes of white cells are powerful pharmacological mediators that are implicated in many immunological reactions. The most powerful effects (bronchoconstriction and mucus secretion) are seen in asthma. The circulatory effects are local, except perhaps in endotoxin shock. Apart from corticosteroids, there are as yet no inhibitors in use in therapeutics.

Topics: Animals; Asthma; Humans; Inflammation; Leukotriene B4; Lipoxygenase; Lung; Lymphocytes; Prostaglandin-Endoperoxide Synthases; SRS-A

Arachidonic acid metabolites may play a role in the pathophysiology of bronchial asthma, influencing bronchial tone, airways inflammation and bronchial hyperreactivity. This study was designed to investigate the effect of nedocromil sodium, at a range of concentrations, on the metabolism of arachidonic acid released from alveolar macrophages (AMs) obtained by bronchoalveolar lavage in healthy and asthmatic subjects. The only effect of nedocromil sodium observed in this study was a slight decrease in LTD4 synthesis by AMs from asthmatic patients. This possible effect of nedocromil sodium on LTD4 metabolism deserves further investigation.

Topics: Asthma; Calcimycin; Chromatography, Thin Layer; Humans; Leukotriene B4; Nedocromil; Pulmonary Alveoli; Quinolines; SRS-A; Thromboxane B2

Two groups of six adults with persistent asthma, who were identical clinically, received 0.1 or 4 g of purified eicosapentaenoic acid ethyl ester (EPA) daily for 8 weeks. Both doses increased significantly the generation of leukotriene B5 (LTB5) from EPA by polymorphonuclear (PMN) and mononuclear leukocytes, while only the high dose decreased leukocyte arachidonic acid (AA) and the generation of LTB4 and prostaglandin E2 from AA. Only the high dose led to inhibition of PMN leukocyte chemotaxis to multiple stimuli by a mean of 57-70% (P less than 0.01), without altering monocyte chemotaxis, the production of platelet-activating factor by mononuclear leukocytes, or the IgE-dependent release of histamine from basophils. Both doses of EPA increased the responses of T lymphocytes to phytohemagglutinin by a mean of 73% or more (P less than 0.01) without modifying the numbers of helper and suppressor T lymphocytes. EPA affects the functions of several types of leukocytes critical to inflammation and immunity.

Topics: Administration, Oral; Asthma; Chemotaxis, Leukocyte; Dinoprostone; Eicosapentaenoic Acid; Fatty Acids; Humans; Leukotriene B4; Lymphocyte Activation; Neutrophils; Prostaglandins E; T-Lymphocytes

Topics: Anaphylaxis; Arachidonic Acid; Arachidonic Acids; Asthma; Blood Proteins; Humans; Leukotriene B4; Macrophages; Platelet Activating Factor; Pulmonary Alveoli

Topics: Asthma; Bronchi; Eicosanoic Acids; Humans; Leukotriene B4; Lung; Prostaglandins; Pulmonary Circulation; SRS-A; Thromboxanes

The formation of 5-lipoxygenase products of arachidonic acid, 5-HETE and 5,12-diHETE, was determined in 100,000 X g supernatant of polymorphonuclear leukocytes from 17 healthy subjects, 17 patients with extrinsic asthma and 15 patients with intrinsic asthma. After the supernatant was incubated with 14C-arachidonic acid in the presence of calcium and indomethacin, the lipoxygenase products of arachidonic acid were separated by thin layer chromatography. The results were expressed as the percentage conversion of 14C-arachidonic acid into the product per 10(7) cells. The formation of 5,12-diHETE, but not of 5-HETE, was significantly increased in the cells from the group of patients with extrinsic asthma (4.38 +/- 0.78%, mean +/- S.E.; p less than 0.01) and intrinsic asthma (6.09 +/- 1.11%; p less than 0.01), when compared to normal subjects (1.74 +/- 0.30%). Both extrinsic and intrinsic asthmatics had significantly enhanced 5-lipoxygenase activity, which was expressed as the sum of percentage conversion of 14C-arachidonic acid into 5-HETE and 5,12-diHETE. The percentage conversion in normal subjects was 4.19 +/- 0.39%, 6.24 +/- 0.84% for 17 patients with extrinsic asthma (p less than 0.05), and 8.59 +/- 1.29% for 15 patients with intrinsic asthma (p less than 0.01). There was no significant difference between these asthmatic groups. These results indicate that 5-lipoxygenase activity is increased in patients with bronchial asthma.

Topics: Adult; Arachidonate Lipoxygenases; Arachidonic Acid; Arachidonic Acids; Asthma; Calcium; Chromatography, Thin Layer; Gas Chromatography-Mass Spectrometry; Humans; Hydroxyeicosatetraenoic Acids; Indomethacin; Leukotriene B4; Lipoxygenase; Middle Aged; Neutrophils; Seasons

The leukotriene generating capacities of ionophore stimulated human eosinophils and neutrophils were compared using specific radioimmunoassays for LTB4 and LTC4. Mixed granulocyte preparations (neutrophils and eosinophils) produced both LTB4 and LTC4 in a time-dependent fashion which was maximal at 10 and 15 min, respectively. Following the separation of eosinophils (greater than 75%) and neutrophils (greater than 90%) by metrizamide gradients, LTC4 production was predominantly from eosinophils, whereas neutrophils were the principal source of LTB4. The concentrations of leukotrienes produced by the eosinophil and neutrophil rich cell preparations were directly proportional to the concentration of ionophore. Following purification of eosinophil derived products by RP-HPLC the LTC4 immunoreactivity corresponded to the elution profile of a synthetic LTC4 marker. Furthermore, in 32 atopic subjects (21 bronchial asthmatics and 11 non-asthmatics) the amounts of LTC4 produced by unseparated leucocytes were directly proportional to the percentage of eosinophils in the total cell suspension. Preferential generation of LTB4 by neutrophils was also demonstrated by immunoreactivity of ionophore stimulated supernatants subjected to RP-HPLC, as well as by its characteristic u.v. absorbance and GC-MS profile and the ability to promote directional neutrophil locomotion (chemotaxis). These experiments support the concept that eosinophils accumulate in tissues partly as a result of the response to neutrophil derived LTB4, and that these cells contribute to the production of sulphidopeptide leukotrienes with subsequent amplification of the acute allergic response.

Topics: Adolescent; Adult; Asthma; Calcimycin; Eosinophils; Granulocytes; Humans; Leukotriene B4; Middle Aged; Neutrophils; Radioimmunoassay; Rhinitis; SRS-A; Urticaria

Leukotrienes have potent biologic actions in various biologic systems. Leukotriene (LT) B4 has inflammatory properties and has been detected in exudates from human inflammatory disease including psoriasis. LTC4, LTD4, and LTE4 have potent bronchoconstrictor actions in vitro and in normal human subjects. LTE4 causes very long-lasting bronchoconstriction. LTC4 and LTD4 are potent vasoconstrictors in coronary and other vascular beds of anesthetized animals. Sulfidopeptide LTs may therefore have a role in asthma and vasospastic disease.

Topics: Animals; Arachidonate Lipoxygenases; Arachidonic Acid; Arachidonic Acids; Asthma; Epoprostenol; Humans; Hypertension, Pulmonary; Indomethacin; Leukotriene B4; Leukotriene E4; Lipoxygenase; Lung; Muscle, Smooth; Research; SRS-A; Vasoconstriction

Airway and pulmonary vascular smooth muscle was obtained from the surgically resected lobe of a human asthmatic allergic to grass pollen who presented with an endobronchial carcinoid tumor. Grass antigen induced sustained contractions of bronchial and pulmonary vein, but not pulmonary artery tissue. Capsaicin did not alter the bronchial response to grass antigen. Contractions to leukotrienes B4, C4, D4 and E4 and methacholine were equivalent to those seen in nonasthmatic human lung tissue, whereas those to histamine were strikingly greater and disproportionate to methacholine. The C3a octapeptide Ala-Ala-Ala-Leu-Gly-Leu-Ala-Arg produced contractions of pulmonary vein and pulmonary artery. These findings are compared with those obtained using human lung samples from nonasthmatic individuals.

Topics: Allergens; Asthma; Bronchi; Capsaicin; Histamine; Humans; In Vitro Techniques; Leukotriene B4; Methacholine Chloride; Methacholine Compounds; Muscle Contraction; Muscle, Smooth; Muscle, Smooth, Vascular; Poaceae; Pulmonary Artery; Pulmonary Veins; Serotonin

The implication of "slow reacting substance of Anaphylaxis" SRS-A in the pathogenesis of asthma was realised in 1950. In recent years SRS-A has been shown to be a mixture of varied composition: The Leukotrienes (LT) C4, D4 and E4. These substances derive their arachidonic acid through the 5-lipoxygenase. The LT B4, which is not conjugated to glutathione (as compared to LT C4, D4 and E4) possesses powerful chemotactic activity and an (indirect) contractile effect on smooth muscle. LTC4, D4, E4 in vitro and in vivo, both by inhalation or intravenously, are powerful bronchoconstrictors clearly superior to histamine. The effects of C4 and LTD4 predominantly affect the peripheral airways.

Topics: Anaphylaxis; Animals; Asthma; Bronchi; Cardiovascular System; Cattle; Chemotaxis; Cricetinae; Dogs; Guinea Pigs; Haplorhini; Humans; In Vitro Techniques; Leukotriene B4; Lung; Mice; Rabbits; Rats; SRS-A

The mechanism of action of ketotifen in the prevention of bronchial asthma is discussed, the pathogenesis of the disease itself being taken as a starting point. The following biological effects of ketotifen may be relevant to its therapeutic activity: the inhibition of release of myotonic mediators, leukotrienes in particular, the inhibition of slow reacting substances-induced bronchoconstriction in vivo, calcium antagonistic properties, and the prevention or reversal of decreased beta-adrenoceptor sensitivity. In asthmatic patients the prevention of bronchospasm due to mediator release and a progressive reduction of bronchial hyperreactivity are the major consequences of these properties.

Topics: Animals; Asthma; Bronchial Spasm; Guinea Pigs; Histamine Release; Humans; In Vitro Techniques; Ketotifen; Leukocytes; Leukotriene B4; Mast Cells; Peritoneum; Rats; SRS-A

Leukotrienes and prostaglandins possess properties which are central in the asthmatic reaction. They are bronchoconstrictors, they inhibit the mucociliary clearance, increase blood flow and permeability and thereby induce edema formation, and they attract and activate leukocytes. They are formed partly by allergic reactions and partly by a large number of other more non-specific reactions. Finally, the concentration of prostanoids has been found increased in the asthmatic reaction in vivo. The leukotrienes have not been traced in vivo in asthmatic attacks so far, but have been found in vivo in man in a specific type I allergic conjunctival reaction. Much evidence suggests that these mediators are relevant in asthmatic diseases, even though prostaglandin inhibitors have no effect in asthma. There still remains the need to investigate the influence on asthmatic diseases by as yet unavailable leukotriene blocking agents. Even though leukotrienes are judged today to be important mediators in asthma, it does not seem reasonable to expect that a single mediator is responsible for asthmatic diseases. Rather, it seems quite likely that asthma is caused by a complex interplay of a large number of mediators, circulating hormones, nervous mechanisms, receptor abnormalities, intracellular metabolic defects, etc. Despite this complexity, investigations in recent years have increased the knowledge of the biochemistry and human physiological effects of leukotrienes and prostaglandins which has created an improved understanding of the asthmatic reaction's pathophysiology, contributed a pharmacological rationale for previously used therapy, and stimulated new perspectives for specific pharmacological research.

Topics: Anti-Inflammatory Agents; Arachidonic Acid; Arachidonic Acids; Asthma; Autacoids; Bronchial Spasm; Ciliary Motility Disorders; Cyclooxygenase Inhibitors; Edema; Enzyme Inhibitors; Histamine Release; Humans; Leukotriene B4; Leukotrienes; Mast Cells; Prostaglandins

Sputum samples from patients with bronchial asthma, chronic bronchitis and cystic fibrosis were examined for the presence of leukotrienes B4, C4 and D4. Following ethanol extraction and purification on Amberlite XAD-8, leukotrienes were identified by high pressure liquid chromatography (HPLC) using the appropriate markers. Fractions from HLPC were also tested for biological activity using both the Boyden chemotaxis assay and FPL 55712 inhibitable contraction of the isolated guinea-pig ileum. LTB4 was detected in the HPLC fractionated sputa from bronchial asthma (seven of seven), chronic bronchitis (four of four) and cystic fibrosis (four of four). In contrast, bioassay on the guinea-pig ileum failed to detect LTC4 or LTD4 in 17 asthmatic sputa, although they were detected in one of five bronchitics and 16 of 25 patients with cystic fibrosis. The activity in eight of these cystic fibrosis sputa was further characterized by HPLC and shown to be LTC4 and/or LTD4. Sputum from 11 of 17 asthmatics, four of 25 patients with cystic fibrosis and two of five bronchitics contained an anaphylatoxin like substance. The majority of sputum samples containing LTB4 also possessed an activity with physical and biological characteristics of the 5(S), 12(S), 6-trans LTB4 isomer. These studies indicate that lipoxygenase products of arachidonic acid metabolism are present in the sputum in various forms of obstructive airways disease. The failure to detect the 'SRS-A' leukotrienes in sputum from bronchial asthma may be attributable to either losses during extraction, the insensitivity of the assay procedure or to more rapid catabolism of LTC4 and LTD4 by bronchial secretions in asthma than in cystic fibrosis.

Topics: Asthma; Biological Assay; Bronchitis; Chemotaxis, Leukocyte; Chromatography, High Pressure Liquid; Cystic Fibrosis; Humans; Leukotriene B4; Lung Diseases, Obstructive; Muscle Contraction; Neutrophils; Sputum; SRS-A

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Asthma; Epoprostenol; Humans; Leukotriene B4; Leukotriene E4; Lipoxygenase Inhibitors; SRS-A

Extreme sensitivity of airways to multiple stimuli characterizes asthma. Airway hyperresponsiveness can be produced experimentally in otherwise healthy subjects or animals by inflammatory damage (e.g., induced by respiratory viruses or by inhaled oxidants). Evidence is presented that cell-to-cell interactions play an important role in experimental hyperreactivity and that similar inflammatory cascades may play a similar role in clinical asthma. Although the importance of epithelial cells and neutrophils has been identified in the present studies, other inflammatory mechanisms (e.g., sensory nerve release of substance P, epithelial mast cells, eosinophils) may also play key roles. In exercise-induced bronchospasm, the stimulus (e.g., cooling or drying) must affect a cell (e.g., one near the epithelial surface) by decreasing temperature or by increasing osmolality. This signal may cause mediator release and a subsequent cascade, leading to contraction of smooth muscle. Environmental irritants (e.g., ozone) inhaled during exercise may potentiate these effects by producing further inflammation.

Topics: Animals; Arachidonic Acids; Asthma; Cell Communication; Chemotactic Factors; Dinoprostone; Dogs; Epithelial Cells; Epithelium; Humans; Hydroxyeicosatetraenoic Acids; Inflammation; Interleukin-8; Leukotriene B4; Neutrophils; Ozone; Prostaglandins E; Sputum

The recent definition of the pathways of generation and structures of diverse products of the lipoxygenation of arachidonic acid has established the identity of a new family of mediators of hypersensitivity and inflammation. Studies of the effects of these mediators have shown that leukotrienes C, D, and E, the constitutents of the slow-reacting substance of anaphylaxis (SRS-A), are extremely potent smooth muscle contractile and vasoactive factors. Leukotriene B is a highly active stimulus of neutrophil and eosinophil functions and suppresses the immunological capabilities of T lymphocytes. The development of specific and sensitive radioimmunoassays has permitted the detection of elevated concentrations of leukotrienes in tissues or exudates in several diseases, including asthma, diverse allergic states, adult respiratory distress syndrome, psoriasis, spondyloarthritis, and gout. The application of selective inhibitors and antagonists of leukotrienes will clarify their pathogenetic contributions in human diseases and may yield new therapeutic approaches.

Topics: Arachidonate Lipoxygenases; Arachidonic Acids; Arthritis; Asthma; Cystic Fibrosis; Humans; Hypersensitivity; Leukotriene A4; Leukotriene B4; Leukotriene E4; Lipoxygenase; Psoriasis; SRS-A; Tears

Topics: Animals; Asthma; Bronchi; Humans; Leukotriene B4; Prostaglandin D2; Prostaglandins D

AA-861, a selective 5-lipoxygenase inhibitor, suppressed A23187-induced formations of 5-HETE and LTB4 in rat peritoneal macrophages. Immunologically-stimulated generation of SRS-A was also inhibited in guinea pig lung and rat peritoneal cavity. AA-861 had no effects on histamine release from rat mast cells or passive cutaneous anaphylaxis in rats. Essentially no antagonistic activity to LTD4 or histamine was observed. This compound exerted an obvious inhibition of allergic bronchoconstriction in guinea pigs and a moderate reduction of carrageenin-induced paw edema and pleurisy in rats. These findings suggest that SRS-A plays an important role in asthmatic and inflammatory reactions.

Topics: Animals; Arachidonate Lipoxygenases; Asthma; Benzoquinones; Edema; Female; Guinea Pigs; Histamine Release; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Lipoxygenase Inhibitors; Lung; Macrophages; Male; Mast Cells; Passive Cutaneous Anaphylaxis; Pleurisy; Quinones; Rats; Rats, Inbred Strains; SRS-A

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Asthma; Calcium; gamma-Glutamyltransferase; Humans; Hyperthyroidism; Leukotriene B4; Leukotriene E4; Membrane Lipids; Mice; Phospholipases; Rats; SRS-A; Thyroid Hormones; Thyroxine; Vitamin E

Topics: Asthma; Histamine; Humans; Leukotriene B4; Mast Cells; Prostaglandins; SRS-A

Topics: Adrenal Cortex Hormones; Allergens; Asthma; Bronchi; Epithelium; Granulocytes; Histamine; Humans; Leukotriene B4; Mast Cells; Muscle Contraction; Permeability

Topics: Arachidonic Acids; Asthma; Humans; Hypersensitivity; Inflammation; Leukotriene A4; Leukotriene B4; Leukotriene E4; SRS-A

Topics: Asthma; Basophils; Bronchi; Chemotactic Factors; Chemotaxis, Leukocyte; Eosinophils; Humans; Interleukin-8; Leukotriene B4; Mast Cells; Neutrophils