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Biomedical subjects

Peter J Barnes

Publications and source records attributed to Peter J Barnes.

At least 163 records · Page 9Linked to original sources
PubMed2002

Analysis of exhaled breath condensate for monitoring airway inflammation.

Several inflammatory mediators have been identified in the exhaled breath condensate (EBC) that is formed by breathing through a cooling system. Analysis of EBC is a noninvasive method that allows repeat measurements of lung inflammation and is potentially useful for monitoring drug therapy. Characterization of the profiles of exhaled markers could help to discriminate between different inflammatory lung diseases; thus, EBC might be a novel, noninvasive approach to monitoring lung diseases. However, several methodological issues, such as standardization of sample collection and validation of analytical techniques, need to be addressed before this method can be applied clinically. Controlled studies are needed to establish the utility of EBC markers for guiding pharmacological treatment in inflammatory lung diseases.

Breath Tests↗
PubMed2002

New treatments for COPD.

COPD is one of the most common diseases in the world, and there is a global increase in prevalence, but there are no drugs available at present that halt the relentless progression of this disease. However, a better understanding of the cellular and molecular mechanisms that are involved in the underlying inflammatory and destructive processes has revealed several new targets for which drugs are now in development, and the prospects for finding new treatments are good.

Bronchodilator Agents↗
PubMed2002

Glucocorticoids reverse IL-1beta-induced impairment of beta-adrenoceptor-mediated relaxation and up-regulation of G-protein-coupled receptor kinases.

1. The aim of the present study was to examine the effects of glucocorticoid dexamethasone on airway responsiveness to albuterol after intratracheal instillation of saline or IL-1beta in Brown-Norway rats in vivo and to elucidate the molecular mechanism of this effect. 2. IL-1beta caused a significant reduction in albuterol-mediated relaxation to protect against MCh-induced bronchoconstriction. Dexamethasone attenuated the IL-1beta-induced impaired relaxation while alone had no effect when compared to rats treated identically with saline. 3. The density of beta(2)-adrenoceptors was significantly reduced in lung membranes harvested from IL-1beta-treated rats, which was associated with impaired isoproterenol- and forskolin-stimulated cyclic AMP accumulation and adenylyl cyclase (AC) activity ex vivo. Dexamethasone did not prevent IL-1beta-induced down-regulation of beta(2)-adrenoceptors but completely blocked IL-1beta-induced impairment of cyclic AMP accumulation and AC activity stimulated by isoproterenol and forskolin. 4. The inhibitory G-protein subtypes, G(ialpha1), G(ialpha2) and G(ialpha3), were detected in lung membranes prepared from all groups of rats but the intensity of G(ialpha1) and G(ialpha2) was markedly increased in IL-1beta-treated rats, which were not prevented by dexamethasone. 5. The activity of cytosolic GRK and the expression of GRK2 and GRK5 were elevated in the lung of IL-1beta-treated rats, which were completely abolished by dexamethasone. 6. These results indicate that treatment of rats with IL-1beta results in desensitization of pulmonary beta(2)-adrenoceptors. In light of data obtained in this study, we propose that both the decrease in AC activity and the increase in GRK activity, which are reversed by dexamethasone, may underlie beta(2)-adrenoceptor desensitization.

Adenylyl Cyclases↗
PubMed2002

Postnatal changes in beta-adrenoceptors in the lung and the effect of hypoxia induced pulmonary hypertension of the newborn.

1. beta-adrenoceptor activation leads to pulmonary vasodilatation. The increase in circulating catecholamines at birth may assist the postnatal fall in vascular resistance by their activation. To study beta(1)- and beta(2)-adrenoceptors during postnatal adaptation, we used [(125)I]-iodocyanopindolol (ICYP) binding to lung membranes and sections to quantify and locate the binding sites in piglets from birth to 14 days of age and compared them with those in adult pigs. In addition, pulmonary hypertension was induced in newborn piglets by hypobaric hypoxia. 2. In lung membranes the equilibrium dissociation constant (K(d)) did not change with age for total beta-adrenoceptors or for beta(2)-adrenoceptors, but there was a significant increase in maximum binding sites (B(max)) between birth and 3 days of age. On tissue sections, B(max) increased between 3 days and adulthood with no change in K(d). 3. Binding sites of beta(1)- and beta(2)-adrenoceptors were localized to the bronchial epithelium, to endothelium of extra- and intra-pulmonary arteries and to lung parenchyma. Total beta-adrenoceptor density increased with age at all locations (P<0.05 - 0.01). At birth intrapulmonary arteries showed no binding, beta(2)-adrenoceptors appeared on day 1 and increased up to 14 days of age. beta(1)-adrenoceptors appeared by 3 days of age and increased with age. 4. Hypobaric hypoxia from birth led to attenuation in the normal postnatal increase in receptor number, but hypoxia from 3 - 6 days did not decrease receptor density. 5. The normal postnatal increase in beta-adrenoceptors suggests a potential for catecholamine induced dilatation in the lung during adaptation which is attenuated in pulmonary hypertension.

Aging↗
PubMed2002

Effect of dopamine receptor agonists on sensory nerve activity: possible therapeutic targets for the treatment of asthma and COPD.

Sensory nerves regulate central and local reflexes such as airway plasma leakage, and cough and their function may be enhanced during inflammation. Evidence suggests that dopamine receptor agonists may inhibit sensory nerve-mediated responses. In this study dopamine inhibited vagal sensory nerve induced microvascular leakage in the rat. In order to characterize the receptor involved rat vagus preparations were utilized. Quinagolide (D(2/3) agonist), ropinirole (D(2/3/4) agonist), SKF 38393 (D(1/5) agonist), AR-C68397AA (Viozan) (dual D(2)/B(2) agonist) and dopamine inhibited hypertonic saline induced depolarization by approximately 50%. Data suggests that AR-C68397AA and quinagolide also inhibited depolarization of the human vagus. The quinagolide response was blocked by sulpiride (D(2/3) antagonist) but not SCH 23390 (D(1/5) antagonist); ropinirole was partially blocked by sulpiride, totally blocked by spiperone (at a concentration that blocks all dopamine receptors) but not by SCH 23390. The response to SKF 38393 was not blocked by sulpiride but was by SCH 23390. The inhibition evoked by AR-C68397AA was only partially blocked by SCH 23390 but not by sulpiride or spiperone whereas dopamine was blocked by spiperone. The effect of dopamine was not stimulus-specific as it inhibited capsaicin-induced depolarization of the rat vagus in a spiperone sensitive manner. In conclusion, dopamine receptor ligands inhibit depolarization of the rat and human vagus. These data suggest that dopamine receptor agonists may be of therapeutic benefit in the treatment of symptoms such as cough and mucus secretion which are evident in respiratory diseases such as asthma and chronic obstructive pulmonary disease.

Animals↗
PubMed2002

Exhaled leukotrienes and prostaglandins in asthma.

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Adult↗
PubMed2002

p38 Mitogen-activated protein kinase-induced glucocorticoid receptor phosphorylation reduces its activity: role in steroid-insensitive asthma.

BACKGROUND: Although glucocorticoids are the most effective treatment for chronic inflammatory diseases, such as asthma, some patients show a poor response. IL-2 combined with IL-4 can alter glucocorticoid receptor (GR) ligand-binding affinity and modulate glucocorticoid function. OBJECTIVE: We sought to confirm the altered ligand-binding affinity in a distinct group of steroid-dependent asthmatic subjects and examine the mechanism by which IL-2 and IL-4 modify the ligand-binding affinity of the GR. METHODS: We examined PBMCs from healthy subjects, subjects with mild asthma, and steroid-dependent subjects with severe asthma using dexamethasone-binding assays and Western blot analysis of GR and phosphorylated activated transcription factor 2 expression. GR phosphorylation was measured after orthophosphate labeling and immunoprecipitation and cytokine production by means of ELISA. RESULTS: GR ligand-binding affinity was reduced in the nucleus but not in the cytoplasm of steroid-dependent asthmatic subjects compared with that seen in healthy subjects (dissociation constant, 39.8 +/- 4.6 vs. 6.79 +/- 0.8 nmol/L). This difference in ligand-binding affinity could be mimicked by IL-2 and IL-4 cotreatment and was blocked by the p38 mitogen-activated kinase (MAPK) inhibitor SB203580. Activation of p38 MAPK by IL-2 and IL-4, as shown by means of phosphorylation of activated transcription factor 2, resulted in GR phosphorylation and reduced dexamethasone repression of LPS-stimulated GM-CSF release. p38 MAPK phosphorylation of CD2(+) T cells occurred on serine residues. The ability of dexamethasone to modulate IL-10 release was also inhibited by IL-2 and IL-4 cotreatment. These effects were also inhibited by SB203580. CONCLUSION: These data show that p38 MAPK inhibitors may have potential in reversing glucocorticoid insensitivity and reestablishing the beneficial effects of glucocorticoids in patients with severe asthma.

Administration, Oral↗
PubMed2002

Cytokine modulators as novel therapies for asthma.

Cytokines play a critical role in orchestrating and perpetuating inflammation in asthmatic airways and several specific cytokine and chemokine inhibitors are now in development for the treatment of asthma. Inhibition of IL-4 with soluble IL-4 receptors has shown promising early results in asthma. Anti-IL-5 antibody is very effective at inhibiting peripheral blood and airway eosinophils but does not appear to be effective in symptomatic asthma. Inhibitory cytokines, such as IL-10, interferons, and IL-12 are less promising because systemic delivery produces intolerable side effects. Inhibition of TNF-alpha may be useful in severe asthma. Many chemokines are involved in the inflammatory response of asthma, and small-molecule inhibitors of chemokine receptors are in development. CCR3 antagonists are now in clinical development for the treatment of asthma. Because so many cytokines are involved in asthma, drugs that inhibit the synthesis of multiple cytokines may prove to be more useful. Several such classes of drug are now in clinical development, and the risk of side effects with these nonspecific inhibitors may be reduced by the inhaled route of delivery.

Asthma↗
PubMed2002

Alveolar macrophage-mediated elastolysis: roles of matrix metalloproteinases, cysteine, and serine proteases.

Chronic obstructive pulmonary disease (COPD) is a common lung disease with cigarette smoking as the major etiological factor, but only 15% of smokers develop COPD. Destruction of lung elastin observed in COPD is mediated by many enzymes, including cysteine, serine, and matrix metalloproteinases (MMP). The contribution of these enzymes to the lung elastolytic load, released from alveolar macrophages collected from nonsmokers, healthy smokers, and COPD patients, was examined by radiolabeled elastin as substrate in the presence of specific enzyme inhibitors. The activity of MMP was further examined by zymography and Western blotting. COPD macrophages degraded more elastin than either of the other groups. Elastolysis was greatest in the initial 24 h. Through the 72-h culture period, the contribution to elastolysis of serine elastases decreased, MMP increased, and cysteine elastases remained constant. The increased release of elastolytic enzymes in COPD subjects may explain why some smokers develop COPD. This difference may be due to unknown susceptibility factors. Serine proteases play a significant role; however, other enzymes, particularly the MMP, deserve further investigation.

Aged↗
PubMed2002

Hydrogen peroxide reverses IL-5 afforded eosinophil survival and promotes constitutive human eosinophil apoptosis.

BACKGROUND: Eosinophils play a central role in the induction and perpetuation of allergic inflammatory responses. The present study was performed to investigate the effects of reactive oxygen intermediates on constitutive apoptosis as well as on interleukin (IL)-5 afforded human eosinophil survival. METHODS: Peripheral blood eosinophils were isolated by CD16-negative selection to >99% purity and were cultured for 48 h. The number of apoptotic eosinophils in the culture was assessed by flow cytometric analysis of relative DNA content in propidium-iodide-stained cells, annexin-V binding or by morphological analysis. Apoptosis was confirmed by the appearance of a typical ladder pattern in the DNA fragmentation assay by agarose gel electrophoresis. RESULTS: Exogenous H(2)O(2) reversed IL-5-afforded eosinophil survival by inducing apoptosis. Constitutive eosinophil apoptosis was inhibited by a reduction of intracellular levels of H(2)O(2) by catalase. Exogenous H(2)O(2) increased the rate of constitutive apoptosis. CONCLUSIONS: Our results suggest that H(2)O(2) may play a role in the downregulation of eosinophilic inflammation by inducing eosinophil apoptosis.

Apoptosis↗
PubMed2002

Expression and regulation of inducible nitric oxide synthase from human primary airway epithelial cells.

Elevated levels of exhaled nitric oxide are seen in inflammatory airway diseases such as asthma, but the cellular source remains unknown. This study investigated whether human airway epithelial cells express inducible nitric oxide synthase (iNOS). Human bronchial epithelial cells stimulated with 50 ng/ml interleukin-1beta, tumor necrosis factor-alpha, and interferon-gamma express iNOS mRNA, protein and increased nitrite in the cell culture media, which was inhibited by the selective iNOS inhibitor 1400W. Cells derived from subjects with asthma produced less nitrite than cells from normal subjects (6.59 +/- 0.99 microM nitrite, n = 15 versus 3.89 +/- 0.42 microM nitrite, n = 20; P < 0.05). This was not attributed to steroid treatment of subjects with asthma because there was no difference in the amount of nitrite released from steroid-naive and steroid-treated cells (3.51 +/- 0.46 versus 4.27 +/- 0.7 microM nitrite, n = 10). Neither dexamethasone nor budesonide inhibited iNOS mRNA induction, protein expression, or nitrite accumulation. The cells were not steroid insensitive because steroids inhibited GM-CSF release. Therefore, although these cells express iNOS under inflammatory conditions, they do not appear to be regulated directly by glucocorticosteroids.

Administration, Topical↗
PubMed2002

Release and activity of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 by alveolar macrophages from patients with chronic obstructive pulmonary disease.

Destruction of lung elastin is critical for development of emphysema associated with chronic obstructive pulmonary disease (COPD). Lung macrophages release elastolytic enzymes, including matrix metalloproteinase (MMP)-9, along with tissue inhibitors of MMP (TIMP). We examined the production and activity of macrophage-derived MMP-9 and TIMP-1 from alveolar macrophages (AM) from smokers with COPD, healthy smokers (HS), and nonsmokers (NS). AM were stimulated with either lipopolysaccharide (LPS), interleukin (IL)-1 beta, or cigarette smoke-conditioned culture medium (CSM). AM from patients with COPD released greater amounts of MMP-9 with greater enzymatic activity than HS and NS. In contrast, AM from NS released more TIMP-1 than cells from HS and subjects with COPD. LPS and IL-1 beta caused a dose-dependent increase in MMP-9 release and activity, together with increased levels of TIMP-1. Dexamethasone prevented the increase in MMP-9 release, and increased TIMP-1 release. CSM increased MMP-9 and TIMP-1 release from AM of all groups. Dexamethasone decreased CSM-stimulated MMP-9 release, but had no effect on MMP-9 activity This study suggests that macrophages might be important in the development of COPD because these cells exhibit increased levels of elastolytic activity.

Aged↗
PubMed2002

Tiotropium bromide: a novel once-daily anticholinergic bronchodilator for the treatment of COPD.

Tiotropium bromide (Spiriva, BA679BR, Boehringer Ingelheim) is a novel inhaled, long-acting anticholinergic bronchodilator that is employed as a once-daily maintenance treatment for patients with chronic obstructive pulmonary disease (COPD). Like ipratropium bromide, tiotropium bromide is a quaternary ammonium derivative that binds to muscarinic receptors. However, although tiotropium binds with high affinity to muscarinic receptors of M1-, M2- and M3-subtypes, it dissociates very slowly from M1- and M3-receptors but more rapidly from M2-receptors, thereby giving it a unique kinetic selectivity. To date, the short-acting anticholinergic agents ipratropium and oxitropium bromide have been extensively employed as bronchodilator therapy for patients with COPD. Indeed, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy emphasises the role of bronchodilators in symptomatic management of all stages of COPD. It is encouraging that tiotropium given once daily from a dry powder inhaler at 18 g has been shown to cause greater improvement in lung function and reduction in symptoms than ipratropium bromide given four times daily. Furthermore, clinical studies over a 1-year period have demonstrated that tiotropium has impressive and maintained effects on lung function, symptoms and health-related quality of life, and may also reduce exacerbations. In a recent large scale comparative study over 6 months, tiotropium has been shown to cause superior bronchodilation and symptomatic improvement when compared to twice daily salmeterol in COPD. The only significant reported adverse event is dry mouth, which is found in approximately 10%-15% of subjects, but this is reversible and rarely causes discontinuation of therapy. Based on these promising features, it is likely that tiotropium used alone or in combination with other bronchodilators will emerge as first-line maintenance treatment for patients with airway obstruction due to COPD.

Administration, Inhalation↗
PubMed2002

Comparison of the effects of salmeterol and formoterol in patients with severe asthma.

STUDY OBJECTIVE: Several studies have demonstrated the superiority of salmeterol and formoterol to either regular treatment with albuterol or placebo. However, to date there have been no trials comparing the efficacy of salmeterol and formoterol in patients with severe asthma. DESIGN: We undertook a randomized, placebo-controlled, crossover study to compare 4 weeks of treatment with inhaled formoterol (12 microg twice daily) or salmeterol (50 microg twice daily) in patients with severe asthma whose conditions were not being adequately controlled by therapy with high doses of inhaled corticosteroids (i.e., > or = 1,500 microg daily) or with regular oral corticosteroid treatment. Morning pretreatment peak expiratory flow (PEF) during the last 14 days of the treatment period was the primary outcome variable. Patients recorded morning and evening pretreatment PEF, daytime and nighttime symptom scores, and any use of rescue medication. Spirometry and bronchial reversibility were performed after each treatment. RESULTS: Forty-two nonsmoking patients (29 women; mean age, 45 +/- 2 years; mean [+/- SEM] FEV(1), 61.8 +/- 3.4% of predicted) took part in the trial, and 27 patients completed the trial. The mean morning PEF was greater in patients receiving formoterol (mean increase, 14.4 L/min; 95% confidence interval [CI]. 0.2 to 28.6) or salmeterol (mean increase, 14.8 L/min; 95% CI, 0.5 to 29.1) compared with those receiving placebo, but there was no difference between these treatments. There were no significant treatment effects for any of the secondary outcome variables (i.e., FEV(1,) FVC, mean evening PEF, mean daytime symptom score, or nighttime symptom score). CONCLUSION: We conclude that the long-acting beta(2)-agonists salmeterol and formoterol improve morning PEF in patients with severe asthma, but that there is no difference in efficacy between the two drugs.

Adrenergic beta-Agonists↗
PubMed2002

Increased 8-isoprostane and interleukin-6 in breath condensate of obstructive sleep apnea patients.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is characterized by repeated episodes of upper airways obstruction during sleep that result in episodes of hypoxia. An increase of systemic biomarkers of inflammation and oxidative stress has been found in patients with OSA and obesity. DESIGN: The aim of this study was to measure the levels of markers of inflammation (interleukin [IL]-6) and oxidative stress (8-isoprostane) in the exhaled breath condensate of OSA and obese patients. PATIENTS AND METHODS: Eighteen OSA patients (13 men; mean [+/- SEM] age, 44 +/- 7 years), 10 obese subjects (4 men; mean age, 39 +/- 8 years), and 15 healthy age-matched subjects (8 men; mean age, 42 +/- 4 years) were recruited. IL-6 and 8-isoprostane were measured in exhaled breath condensate by a specific enzyme immunoassay kit. MEASUREMENTS AND RESULTS: Higher concentrations of IL-6 were found in OSA patients (8.7 +/- 0.3 pg/mL) than in healthy control subjects (1.6 +/- 0.1 pg/mL; p < 0.0001). Obese subjects also had higher levels than healthy control subjects, but lower levels than OSA patients (2.1 +/- 0.2 pg/mL, p < 0.05 and p < 0.0001 respectively). Furthermore, 8-isoprostane levels were found to be higher in OSA patients (7.4 +/- 0.7 pg/mL) than in obese subjects (5 +/- 0.3 pg/mL; p = 0.4) and healthy subjects (4.5 +/- 0.5 pg/mL; p < 0.005). We found a positive correlation between these two markers and neck circumference and apnea/hypopnea index. CONCLUSIONS: These findings suggest that inflammation and oxidative stress are characteristic in the airways of OSA patients but not in obese subjects, and that their levels depend on the severity of the OSA. The measurement of IL-6 and 8-isoprostane levels may prove to be useful in screening and monitoring obese patients who have a high risk of developing OSA.

Adult↗
PubMed2002

Matrix metalloproteinase-9 expression in asthma: effect of asthma severity, allergen challenge, and inhaled corticosteroids.

BACKGROUND: Asthma is associated with remodeling of the extracellular matrix (ECM) and increased airway obstruction, and the mechanisms of this process are unknown. Matrix metalloproteinases (MMPs) are a group of enzymes capable of degrading the ECM. They are released along with their inhibitors, tissue inhibitor of MMP (TIMP). STUDY OBJECTIVE: s: To determine whether severe, persistent asthma is associated with increased levels of MMP-9 in the airway compared with mild asthma, and to assess the effect of both allergen exposure and steroid treatment on MMP-9 and TIMP-1 levels. DESIGN: Prospective analysis of levels and activity of MMP-9 and TIMP-1 in BAL fluid (BALF) and induced sputum obtained from asthmatics of differing disease severity. In patients with mild asthma, MMP-9 and TIMP-1 levels were studied in induced sputum following allergen challenge and in BALF after inhaled steroid therapy. PATIENTS: Eighteen patients with mild asthma, 10 patients with severe asthma, and 10 nonsmoking, atopic subjects had their sputum studied. Fourteen of the patients with mild asthma underwent allergen challenge. BAL was collected from 16 patients with mild asthma before and after 4 weeks treatment with inhaled budesonide, 800 micro g bid, or placebo. RESULTS: Patients with severe asthma had increased levels and activity of sputum MMP-9 in their sputum compared with patients with mild asthma and normal subjects. Allergen challenge increased the MMP-9/TIMP-1 ratio and MMP-9 activity. Inhaled budesonide had no effect on MMP-9 or TIMP-1 in patients with mild asthma. CONCLUSIONS: MMP-9 may play a role in chronic airway inflammation and remodeling in asthma, as concentrations are increased in severe, persistent asthma and following allergen challenge. Inhaled steroids may not affect MMP-9 and TIMP in patients with mild asthma, and additional studies in patients with more severe asthma are needed.

Administration, Inhalation↗
PubMed2002

Current and future therapies for airway mucus hypersecretion.

Mucus hypersecretion is a prominent feature of chronic inflammatory diseases of the airways, including asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis, but little is known about the effects of current therapies for airway disease because of the difficulties in quantifying mucus hypersecretion in clinical studies. Anticholinergics may reduce mucus hypersecretion, whereas beta2 agonists and mucolytics have little obvious effect. Corticosteroids are highly effective in inhibiting mucus hypersecretion in asthma by suppressing the underlying inflammatory process, but are ineffective in COPD and cystic fibrosis. Novel approaches in the future may include inhibition of sensory neuropeptides by tachykinin antagonists, modulators of sensory nerves or K+ channel openers. Inhibition of Th2 cytokines (interleukin [IL]4, IL9, IL13) may also be effective in asthma. In COPD inhibition of neutrophil-derived proteases by small molecule inhibitors or inhibiting neutrophilic inflammation in the airways by reducing neutrophil chemotaxis may also be effective strategies. Several novel targets involved in mucus hypersecretion have recently been identified, including epidermal growth factor receptors, MARCKs, Ca2+-activated Cl- channels and mitogen-activated protein kinases. However, the clinical benefits from inhibiting mucus hypersecretion are still not certain, casting some doubts on this therapeutic approach.

Anti-Asthmatic Agents↗