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Effects of SR 140333 and SR 48968 on antigen and substance P‐induced activation of guinea‐pig alveolar macrophages
Author(s) -
Elisabeth Boichot,
Nicolas Germain,
Xavier EmondsAlt,
C. Advenier,
Vincent Lagente
Publication year - 1998
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1046/j.1365-2222.1998.00398.x
Subject(s) - phosphoramidon , substance p , guinea pig , bronchoalveolar lavage , ovalbumin , neprilysin , pulmonary alveolus , immunology , chemistry , nk1 receptor antagonist , medicine , endocrinology , receptor , pharmacology , antigen , lung , neuropeptide , respiratory disease , biochemistry , endothelin receptor , enzyme
Background Tachykinins, such as substance P, might be involved in the development of airway hyperresponsiveness and airway inflammation. Objective This study was designed to investigate the effects of the tachykinin NK 1 receptor antagonist SR 140333 (Nolpitantium) and the NK 2 receptor antagonist SR 48968 (Saredutant) on the activation of alveolar macrophages in the guinea‐pig. Methods 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. Results 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. Conclusion The present data demonstrate the importance of NK 1 ‐ and NK 2 ‐receptor stimulation in the development of substance P‐induced increased reactivity of alveolar macrophages.