Kinins are generated in nasal secretions during allergic reactions and during induced rhinovirus colds. To determine if kinins may contribute to the symptomatology of these inflammatory reactions, 8 subjects were challenged with increasing doses of bradykinin or with placebo. Levels of albumin, histamine, and N-alpha-tosyl-L-arginine methyl ester (TAME)-esterase were measured in nasal lavages, and symptom scores were noted. No symptoms or increases in mediators or protein were observed after placebo challenge. Symptom scores increased in a dose-dependent manner, however, in response to bradykinin challenge. Increased symptoms were associated with significant increases in albumin and TAME-esterase activity, but no increases in histamine were observed. Nasal conductance measurements confirmed that bradykinin induces dose-dependent unilateral obstruction in the challenged nostril. Other common symptoms were rhinorrhea and, of particular relevance to rhinovirus infections, a persistent sore throat. We conclude that bradykinin causes increased vascular permeability and rhinitis, which are independent of mast cell mediator release. Kinins may, therefore, contribute to the symptomatology of inflammatory reactions of the upper airways, including the common cold.
BackgroundIt is widely recognized that deep inspiration (DI), either before methacholine (MCh) challenge (Bronchoprotection, BP) or after MCh challenge (Bronchodilation, BD) protects against this challenge in healthy individuals, but not in asthmatics. Sulforaphane, a dietary antioxidant and antiinflammatory phytochemical derived from broccoli, may affect the pulmonary bronchoconstrictor responses to MCh and the responses to DI in asthmatic patients.MethodsForty-five moderate asthmatics were administered sulforaphane (100 μmol daily for 14 days), BP, BD, lung volumes by body-plethsmography, and airway morphology by computed tomography (CT) were measured pre- and post sulforaphane consumption.ResultsSulforaphane ameliorated the bronchoconstrictor effects of MCh on FEV1 significantly (on average by 21 %; p = 0.01) in 60 % of these asthmatics. Interestingly, in 20 % of the asthmatics, sulforaphane aggravated the bronchoconstrictor effects of MCh and in a similar number was without effect, documenting the great heterogeneity of the responsiveness of these individuals to sulforaphane. Moreover, in individuals in whom the FEV1 response to MCh challenge decreased after sulforaphane administration, i.e., sulforaphane was protective, the activities of Nrf2-regulated antioxidant and anti-inflammatory genes decreased. In contrast, individuals in whom sulforaphane treatment enhanced the FEV1 response to MCh, had increased expression of the activities of these genes. High resolution CT scans disclosed that in asthmatics sulforaphane treatment resulted in a significant reduction in specific airway resistance and also increased small airway luminal area and airway trapping modestly but significantly.ConclusionThese findings suggest the potential value of blocking the bronchoconstrictor hyperresponsiveness in some types of asthmatics by phytochemicals such as sulforaphane.
Endothelin-1 (ET-1), a 21 amino acid peptide, and its receptors are distributed in the mammalian respiratory tract. To examine the responses of human upper airways to ET-1, we investigated the effects of intranasal administration of ET-1 to nine symptomatic allergic and nine nonallergic volunteers. Paper discs were used to administer ET-1 or diluent to one side of the nasal mucosa, and to collect secretions from the ipsilateral (challenged) and contralateral (opposite) nostrils. ET-1 (0.3-10 micrograms), but not diluent, induced dose-dependent bilateral increases in secretion weights, lysozyme secretion, symptoms of rhinorrhea and itch, and sneezing in both populations. ET-1 did not induce albumin secretion, histamine release, or symptoms of nasal congestion. Compared with the nonallergic subjects, allergic individuals sneezed more and had significantly higher bilateral secretion weights, contralateral lysozyme secretion, and symptoms of rhinorrhea following ET-1 provocation. In summary, ET-1 induced symptoms relevant to inflammatory upper airway diseases in allergic and nonallergic subjects. However, responses of allergic subjects were more pronounced, particularly with respect to symptoms associated with neural reflex responses, such as sneezing and contralateral secretion. Therefore, allergic inflammation enhances responsiveness of the nasal mucosa to ET-1.
BackgroundThe upper respiratory tract functions to protect lower respiratory structures from chemical and biological agents in inspired air. Cellular oxidative stress leading to acute and chronic inflammation contributes to the resultant pathology in many of these exposures and is typical of allergic disease, chronic sinusitis, pollutant exposure, and bacterial and viral infections. Little is known about the effective means by which topical treatment of the nose can strengthen its antioxidant and anti-inflammatory defenses. The present study was undertaken to determine if naturally-occurring plant oils with reported antioxidant activity can provide mechanisms through which upper respiratory protection might occur.MethodsControlled exposure of the upper respiratory system to ozone and nasal biopsy were carried out in healthy human subjects to assess mitigation of the ozone-induced inflammatory response and to assess gene expression in the nasal mucosa induced by a mixture of five naturally-occurring antioxidant oils - aloe, coconut, orange, peppermint and vitamin E. Cells of the BEAS-2B and NCI-H23 epithelial cell lines were used to investigate the source and potential intracellular mechanisms of action responsible for oil-induced anti-inflammatory activity.ResultsAerosolized pretreatment with the mixed oil preparation significantly attenuated ozone-induced nasal inflammation. Although most oil components may reduce oxidant stress by undergoing reduction, orange oil was demonstrated to have the ability to induce long-lasting gene expression of several antioxidant enzymes linked to Nrf2, including HO-1, NQO1, GCLm and GCLc, and to mitigate the pro-inflammatory signaling of endotoxin in cell culture systems. Nrf2 activation was demonstrated. Treatment with the aerosolized oil preparation increased baseline levels of nasal mucosal HO-1 expression in 9 of 12 subjects.ConclusionsThese data indicate that selected oil-based antioxidant preparations can effectively reduce inflammation associated with oxidant stress-related challenge to the nasal mucosa. The potential for some oils to activate intracellular antioxidant pathways may provide a powerful mechanism through which effective and persistent cytoprotection against airborne environmental exposures can be provided in the upper respiratory mucosa.
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