ovalbumin and phosphoramidon

Topics: Animals; Anti-Bacterial Agents; Bronchi; Glycopeptides; Guinea Pigs; Humans; In Vitro Techniques; Leukotriene C4; Muscle Contraction; Muscle, Smooth; Ovalbumin; Tachykinins; Thiorphan

Inhaled bradykinin causes bronchoconstriction in asthmatic subjects but not nonasthmatics. To date, animal studies with inhaled bradykinin have been performed only in anesthetized guinea pigs and rats, where it causes bronchoconstriction through sensory nerve pathways. In the present study, airway function was recorded in conscious guinea pigs by whole-body plethysmography. Inhaled bradykinin (1 mM, 20 s) caused bronchoconstriction and influx of inflammatory cells to the lungs, but only when the enzymatic breakdown of bradykinin by angiotensin-converting enzyme and neutral endopeptidase was inhibited by captopril (1 mg/kg i.p.) and phosphoramidon (10 mM, 20-min inhalation), respectively. The bronchoconstriction and cell influx were antagonized by the B(2) kinin receptor antagonist 4-(S)-amino-5-(4-{4-[2,4-dichloro-3-(2,4-dimethyl-8-quinolyloxymethyl)phenylsulfonamido]-tetrahydro-2H-4-pyranylcarbonyl}piperazino)-5-oxopentyl](trimethyl)ammonium chloride hydrochloride (MEN16132) when given by inhalation (1 and 10 μM, 20 min) and are therefore mediated via B(2) kinin receptors. However, neither intraperitioneal MEN16132 nor the peptide B(2) antagonist icatibant, by inhalation, antagonized these bradykinin responses. Sensitization of guinea pigs with ovalbumin was not sufficient to induce airway hyperreactivity (AHR) to the bronchoconstriction by inhaled bradykinin. However, ovalbumin challenge of sensitized guinea pigs caused AHR to bradykinin and histamine. Infection of guinea pigs by nasal instillation of parainfluenza-3 virus produced AHR to inhaled histamine and lung influx of inflammatory cells. These responses were attenuated by the bradykinin B(2) receptor antagonist MEN16132 and H-(4-chloro)DPhe-2'(1-naphthylalanine)-(3-aminopropyl)guanidine (VA999024), an inhibitor of tissue kallikrein, the enzyme responsible for lung synthesis of bradykinin. These results suggest that bradykinin is involved in virus-induced inflammatory cell influx and AHR.

Topics: Animals; Bradykinin; Bradykinin B2 Receptor Antagonists; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Bronchoconstriction; Captopril; Cell Count; Glycopeptides; Guinea Pigs; Histamine; Male; Ornithine; Ovalbumin; Parainfluenza Virus 3, Human; Peptides; Plethysmography, Whole Body; Pneumonia; Protease Inhibitors; Respirovirus Infections; Sulfonamides; Tissue Kallikreins

We investigated the effect of the orally active non-peptide bradykinin B2 receptor antagonist, FR173657 (E)-3-(6-acetamido-3-pyridyl)-N-[N-[2.4-di-chloro-3-[(2-methyl-8-quinoli nyl)oxymethyl]phenyl]-N-methy-laminocarbonylmethyl] acrylamide), on plasma extravasation mediated by activation of sensory nerves in guinea pig airways. Plasma extravasation was assessed by the photometric measurement of the extravasated Evans blue after formamide extraction. We found that the increase in Evans blue dye extravasation evoked by an aerosol of bradykinin (0.1 mM, 2 min) in the presence of phosphoramidon (2.5 mg/kg, i.v.) was abolished completely by FR173657 (20 mg/kg, p.o.) in the trachea and main bronchi. In sensitized guinea pigs pretreated with phosphoramidon, FR173657 (20 mg/kg, p.o.) inhibited plasma extravasation evoked by ovalbumin aerosol (5%, 2 min) by 77+/-14.2% in the trachea and 65+/-11.2% in the main bronchi. FR173657 (20 mg/kg, p.o.) did not affect the plasma extravasation caused by aerosolised capsaicin. These findings suggest that FR173657 is an orally active, promising anti-inflammatory agent for kinin-dependent inflammation following antigen challenge.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bradykinin; Bradykinin Receptor Antagonists; Bronchi; Capsaicin; Evans Blue; Extravasation of Diagnostic and Therapeutic Materials; Glycopeptides; Guinea Pigs; Inflammation; Male; Ovalbumin; Photometry; Protease Inhibitors; Quinolines; Respiratory System; Trachea

Changes in the immunoreactive ET-1 levels during the anaphylactic reaction of airway tissue from ovalbumin-sensitized guinea pigs were investigated. ET-1-immunoreactivity (ET-IR) was detected in the epithelial and smooth muscle layers of tracheal sections from normal guinea pigs and it was enhanced slightly by phosphoramidon (1 microM) treatment. The ET-IR level of the epithelial layer of ovalbumin-treated tissue from actively sensitized animals was slightly higher than that from normal animals, but it was enhanced markedly by phosphoramidon (1 microM) treatment. Furthermore, the mean ET-IR level of homogenates of antigen-treated tracheal tissues from sensitized guinea pigs (22.8 +/- 1.55 fmol mg-1 protein, n = 5) was significantly higher than the corresponding normal level (12.3 +/- 1.21 fmol mg-1 protein, n = 5). These results suggest that increased epithelial airway ET-1 levels contribute to the anaphylactic reaction of guinea pig airways.

Topics: Anaphylaxis; Animals; Antigens; Endothelin-1; Epithelium; Glycopeptides; Guinea Pigs; Immunohistochemistry; Male; Muscle, Smooth; Ovalbumin; Trachea

An inhalation of ultrasonically nebulized distilled water (UNDW) induces bronchoconstriction only in asthmatics, but the mechanism underlying the response is not fully understood. We recently showed that bronchoconstriction occurs immediately after UNDW is inhaled 20min after an aerosolized antigen challenge in passively sensitized guinea-pigs.. This study was conducted to examine the role of tachykinins in this response.. Passively sensitized animals were anaesthetized and artificially ventilated, and changes in pressure at the airway opening (Pao) were measured as an overall index of airway narrowing. A tachykinin NK1 and NK2 dual receptor antagonist, FK224, and a tachykinin NK1 selective antagonist, FK888, were intravenously administered 15 min after the antigen challenge. The effects of capsaicin desensitization and a neutral endopeptidase inhibitor, phosphoramidon, were also examined.. FK224 and FK888 significantly (P < 0.05 and P < 0.05, respectively) reduced the time course curve of the increase in Pao caused by UNDW inhalation in a dose-dependent manner. The percentage increase in Pao from the preantigen challenge value at 1 min after the UNDW inhalation was 267.4+/-17.1, 358.0+/-33.7 and 412.4+/-27.6% with 10 mg/kg of FK224, 1.0 mg/kg of FK224 and vehicle, respectively, (P<0.01 between 10 mg/kg of FK224 and vehicle) and the value was 254.4+/-48.5% with 10 mg/kg of FK888, 327.1+/-57.6% with 1.0 mg/kg of FK888 and 418.5+/-39.0% with vehicle, respectively (P < 0.05 between 10 mg/kg of FK888 and vehicle). The capsaicin desensitization, but not phosphoramidon, significantly reduced the UNDW-induced increase in Pao.. These results suggest that tachykinins, at least substance P, are involved in a part of the UNDW-induced bronchoconstriction in our guinea-pig model.

Topics: Animals; Bronchoconstriction; Capsaicin; Dipeptides; Disease Models, Animal; Glycopeptides; Guinea Pigs; Indoles; Killer Cells, Natural; Male; Nebulizers and Vaporizers; Ovalbumin; Peptides, Cyclic; Respiration; Tachykinins; Water

Tachykinins, such as substance P, might be involved in the development of airway hyperresponsiveness and airway inflammation.. This study was designed to investigate the effects of the tachykinin NK1 receptor antagonist SR 140333 (Nolpitantium) and the NK2 receptor antagonist SR 48968 (Saredutant) on the activation of alveolar macrophages in the guinea-pig.. Guinea-pigs sensitized and challenged by ovalbumin administered by aerosol or naive guinea-pigs were exposed by aerosol to the neutral endopeptidase, phosphoramidon and, 15 min later, to substance P. Twenty-four hours later, bronchoalveolar lavages were performed and the cell composition of bronchoalveolar lavage fluids and the arachidonate release from alveolar macrophages stimulated in vitro with fMLP were evaluated.. Antigen challenge in sensitized guinea-pigs induced an increase in the total number of cells and granulocytes in the bronchoalveolar lavage fluids that was not reduced by pre-treatment of guinea-pigs with a single dose of SR 140333 or SR 48968 (1 mg/kg). Substance P exposure in phosphoramidon-pretreated guinea-pigs did not induce an increase in the total number of cells. In contrast, antigen or substance P exposure induced a significant increase in the in vitro fMLP-induced arachidonate release from alveolar macrophages. Pre-treatment of the guinea pigs with SR 140333 or SR 48968 did not reduce the increase in arachidonate release from fMLP-stimulated alveolar macrophages from sensitized and challenged guinea-pigs. Pre-treatment of the animals by SR 140333 and SR 48968 reduced the enhanced arachidonate release induced by fMLP from substance P-exposed guinea-pigs.. The present data demonstrate the importance of NK1- and NK2-receptor stimulation in the development of substance P-induced increased reactivity of alveolar macrophages.

Topics: Animals; Antigens; Arachidonic Acid; Benzamides; Bronchoalveolar Lavage; Bronchoalveolar Lavage Fluid; Endopeptidases; Glycopeptides; Guinea Pigs; Macrophage Activation; Macrophages, Alveolar; Male; Neurokinin-1 Receptor Antagonists; Ovalbumin; Piperidines; Quinuclidines; Receptors, Neurokinin-1; Receptors, Neurokinin-2; Substance P

To study the role of tachykinins in allergic responses in the airways of guinea pigs sensitized to ovalbumin (OVA), we examined the bronchial contractile response to allergen in the presence or absence of the tachykinin antagonist FK224 in vitro. Because neutral endopeptidase (NEP) effectively cleaves tachykinins, we incubated bronchial tissues with the NEP inhibitor phosphoramidon (10(-5) M) to maintain the activity of endogenously released tachykinins. Then we added 10(-5)% (10 microns/ml) OVA in the presence or absence of FK224 (10(-5) M). FK224 significantly inhibited OVA-induced contraction plateaued and began to relax, we added 10(-5) M phosphoramidon. In the tissue without FK224, phosphoramidon blocked the relaxation and enhanced the contraction. In contrast, in the tissues treated with FK224, phosphoramidon did not enhance the OVA-induced contraction. The enhancement of the contraction induced by phosphoramidon was not inhibited by the sodium channel blocker tetrodotoxin. These results suggest that (1) allergic response causes release of tachykinin-like substances to induce bronchial contraction in part, (2) these responses are blocked by tachykinin antagonist FK224 and (3) nerve conduction is not necessary for the release of tachykinin-like substances induced by allergic response in the guinea pig bronchus.

Topics: Allergens; Animals; Bronchoconstriction; Drug Hypersensitivity; Glycopeptides; Guinea Pigs; Male; Metalloendopeptidases; Ovalbumin; Peptides, Cyclic; Protease Inhibitors; Tachykinins; Tetrodotoxin

The plasma extravasation evoked by instillation of 5% ovalbumin in the nasal mucosa of sensitized guinea-pigs was potentiated by the neutral endopeptidase inhibitor, phosphoramidon, and was reduced by the tachykinin NK1 receptor antagonist, CP-96,345. The bradykinin B2 receptor antagonist, HOE 140, also reduced the plasma extravasation evoked by the antigen. The combination of HOE 140 and CP-96,345 did not increase further the inhibition caused by HOE 140 alone. Plasma extravasation evoked by instillation of capsaicin was abolished by CP-96,345. HOE 140 blocked and CP-96,345 markedly reduced plasma extravasation caused by instillation of bradykinin. Plasma extravasation evoked by instillation of substance P was not affected by HOE 140. We conclude that antigen challenge causes plasma extravasation in the nasal mucosa of sensitized guinea-pigs, an effect that is due in part to the release of tachykinins from sensory nerve endings. Our evidence suggests that tachykinin release in response to antigen is provoked mainly by the release of kinins.

Topics: Animals; Biphenyl Compounds; Bradykinin; Capillary Permeability; Capsaicin; Evans Blue; Glycopeptides; Guinea Pigs; Hypnotics and Sedatives; In Vitro Techniques; Kinins; Male; Nasal Mucosa; Nerve Endings; Neurokinin-1 Receptor Antagonists; Neurons, Afferent; Ovalbumin; Protease Inhibitors; Substance P; Tachykinins

Topics: Allergens; Animals; Anti-Bacterial Agents; Biphenyl Compounds; Blood Proteins; Glycopeptides; Guinea Pigs; Hypnotics and Sedatives; Immunization; Male; Microcirculation; Neurokinin-1 Receptor Antagonists; Ovalbumin; Receptors, Neurokinin-1; Respiratory System; Substance P

The role of tachykinins released from sensory nerves in bronchoconstriction induced by antigen was studied in sensitized guinea pigs anesthetized with pentobarbital sodium and pretreated with atropine. The combination of NK2 (SR-48968) and NK1 (CP-96,345) tachykinin-receptor antagonists abolished the increase in total pulmonary resistance (RL) evoked by intravenous capsaicin but did not affect the response evoked by intravenous histamine. A small dose of aerosolized ovalbumin (OVA, 0.1%) produced a small increase in RL that was further increased and markedly prolonged by the neutral endopeptidase (NEP) inhibitor phosphoramidon; this bronchoconstrictor effect of OVA was markedly reduced by the NK2-receptor antagonist and was abolished by the combination of the NK1 and NK2-receptor antagonists together. When a larger dose of OVA (0.5%) was used, a maximal bronchoconstrictor response was obtained. Phosphoramidon did not potentiate this response significantly. The combination of NK1- and NK2-receptor antagonists blunted the response at 5 min only slightly but markedly attenuated the later (10-20 min) response. These results show that tachykinins released from sensory nerves play a significant role in antigen-induced bronchoconstriction in guinea pigs. This effect is exaggerated when the normal modulation of neuropeptides by NEP is inhibited and is mediated predominantly by NK2-receptor activation, with a smaller contribution by NK1 receptors.

Topics: Aerosols; Animals; Atropine; Benzamides; Biphenyl Compounds; Bronchoconstriction; Capsaicin; Glycopeptides; Guinea Pigs; Histamine; Immunization; Inflammation; Lung; Male; Neurokinin-1 Receptor Antagonists; Ovalbumin; Piperidines; Pulmonary Circulation; Receptors, Neurokinin-2; Vascular Resistance

To determine whether endogenous tachykinins are released in allergic airway response to contribute to bronchoconstriction and whether neutral endopeptidase (NEP), which effectively cleaves tachykinins, modulates that bronchoconstriction, we studied the effects of the NEP inhibitor phosphoramidon on bronchoconstriction induced by allergic response in anesthetized guinea pigs. We mechanically ventilated the guinea pigs sensitized with ovalbumin (OVA) in a bodyplethysmograph and measured the pulmonary resistance (RL). We exposed the sensitized guinea pigs to doubling concentrations of OVA aerosols from 2(-5)% (wt/vol) until the transpulmonary pressure increased more than twofold from the baseline. After the final exposure, we exposed them to phosphoramidon (10(-4) M) or its vehicle. Phosphoramidon significantly potentiated the increased RL induced by OVA challenge. Phosphoramidon also significantly potentiated the increased RL in the guinea pigs treated with atropine, but the potentiation was significantly reduced. In contrast, phosphoramidon failed to potentiate the increased RL induced by OVA in guinea pigs pretreated with capsaicin. These results suggest that 1) endogenous tachykinin-like substances are released in allergic airway response and that 2) when endogenous NEP is inhibited in the guinea pig airways in vivo, the substances contribute to bronchoconstriction by partly activating the parasympathetic nerve.

Topics: Airway Resistance; Animals; Asthma; Capsaicin; Glycopeptides; Guinea Pigs; Male; Neprilysin; Ovalbumin; Plethysmography, Whole Body; Propranolol; Tachykinins

The effect of phosphoramidon on the increase in pulmonary inflation pressure (PIP) induced by endothelin-1 (ET-1) administered by aerosol in ovalbumin (OA)-sensitized and challenged guinea-pigs was investigated after pretreatment or not of the animals with the neutral endopeptidase inhibitor, phosphoramidon, the cyclooxygenase inhibitor, indomethacin or the platelet activating factor (PAF) antagonist, BN 50730. When guinea-pigs were pretreated by phosphoramidon (0.1 mM, aerosol for 15 min), a significant enhancement of PIP was observed after administration of ET-1 (1 or 3 micrograms ml-1, aerosol for 2 min), whereas these doses of the peptide were only slightly active in control animals. In sensitized and unchallenged guinea-pigs, ET-1 (1 or 3 micrograms.ml-1, aerosol for 2 min) induced, as in controls, a moderate increase in PIP. In contrast, aerosol exposure of OA in sensitized guinea-pigs developed an increased PIP following ET-1 (1 and 3 micrograms.ml-1, aerosol for 2 min) administration, that was non significantly affected by pretreatment of the animals with phosphoramidon after the dose of 3 micrograms ml-1 ET-1. Guinea-pigs exposed to phorphoramidon and treated with indomethacin (10 mg kg-1, i.v.) or BN 50730 (25 mg kg-1, per os) significantly reduced the increase in PIP upon administration of ET-1 (3 micrograms.ml-1, aerosol for 2 min). No inhibitory effect of indomethacin was noted when ET-1 (3 micrograms.ml-1, aerosol for 2 min) was administered to sensitized and OA-exposed guinea-pigs, pretreated or not with phosphoramidon. In contrast, BN 50730 significantly reduced the increase in PIP induced by ET-1 observed in sensitized and OA-exposed guinea-pigs. Moreover, this drug was moderately active in reducing the increase in PIP induced by ET-1, when the animals were pretreated by phosphoramidon. These results suggest that a phosphoramidon-sensitive endopeptidase-like enzyme, present in the airway tissue modulates the effect of ET-1. Furthermore, the increase in PIP to ET-1 observed in aerosol-sensitized and antigen-exposed guinea-pigs appears to be mediated by PAF rather than cyclooxygenase metabolites, even though the participation of other mediators in this process is open.

Topics: Aerosols; Animals; Azepines; Bronchi; Disease Models, Animal; Endothelins; Glycopeptides; Guinea Pigs; Immunization; Indomethacin; Lung; Male; Neprilysin; Ovalbumin; Platelet Activating Factor; Prostaglandin-Endoperoxide Synthases; Respiratory Function Tests; Tetrazoles; Thienopyridines; Time Factors; Triazoles

To study the role of tachykinins and neutral endopeptidase (NEP), an enzyme that degrades tachykinins, in the immune response in the airways of guinea pigs sensitized to ovalbumin (OVA), we examined the bronchial contractile response to OVA by inhibiting NEP in vitro. After incubating bronchial tissues with the NEP inhibitors phosphoramidon and thiorphan, we added 10(-5)% (10 micrograms/ml) OVA. Phosphoramidon and thiorphan (10(-5) M) significantly maintained the contraction that followed the peak contraction. In the next stages of the experiment, when the contraction induced by 10(-5)% OVA reached a plateau and began to relax, we added 10(-5) M phosphoramidon. Phosphoramidon inhibited the relaxation and significantly potentiated the contraction. In tissues treated with 10(-5) M capsaicin to deplete tachykinins, phosphoramidon did not potentiate the OVA-induced contraction, but substance P (10(-6) M) caused contraction. These results suggest that the immune response causes the release of tachykinin-like substances from capsaicin-sensitive nerves to induce bronchial contraction in part. To confirm the mediators that cause the release of the tachykinin-like substances from the bronchus, we also examined whether phosphoramidon potentiates the effect of leukotriene C4 (LTC4), serotonin, histamine, and platelet-activating factor on bronchial contraction. When the contractions induced by these agonists reached a plateau and began to relax, we added phosphoramidon. Phosphoramidon inhibited the relaxation and significantly potentiated the contractile response to 10(-5) M LTC4, and it significantly reduced the relaxing rate of the 10(-6) M serotonin-induced contraction. However, it did not change the effect of histamine and platelet-activating factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Bronchi; Bronchoconstriction; Capsaicin; Glycopeptides; Guinea Pigs; Histamine; Immunization; In Vitro Techniques; Male; Neprilysin; Ovalbumin; Platelet Activating Factor; Serotonin; SRS-A; Thiorphan