title: Evidence for, and characterization of, a lipopolysaccharide-inducible adenosine A2 receptor in human tracheal gland serous cells.
abstract: Human tracheal glands are considered as the principle secretory structures in the bronchotracheal tree. In earlier studies, we successfully performed primary cultures of human tracheal gland (HTG) serous cells and noted that these cells were responsive to many secretagogues including purinergic agonists but not to the inflammatory mediator adenosine. In this study, we demonstrate that adenosine was capable of including stimulation of protein secretion by HTG serous cells which had previously been cultured in pro-inflammatory conditions (induced by lipopolysaccharide (LPS)). This stimulation was inhibited by 8-phenyltheophyllline but not by dipyridamole, which is indicative of a P1 purinoceptor. This inducible receptor is the adenosine A2 subtype [rank potency order: (5'-(N-ethyl)-carboxamidoadenosine (NECA) > adenosine > N6-(phenylisopropyl)-adenosine (PIA); and stimulation of adenylyl cyclase]. The adenosine-induced protein secretion was concentration-dependent, however, increased intracellular cyclic adenosine monophosphate (cAMP) was not dependent on the concentration of adenosine. The adenosine-induced secretion and the ATP-induced secretion were shown to be additive. This study concludes that there is evidence of a LPS-inducible adenosine A2 receptor in human tracheal gland serous cells.
authors.affiliation: Groupe de Recherche sur les Glandes Exocrines, Faculté de Médecine, Marseille, France.
authors.forename: M D
authors.initials: MD
authors.lastname: Merten
authors.forename: W
authors.initials: W
authors.lastname: Kammouni
authors.forename: C
authors.initials: C
authors.lastname: Figarella
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide); D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis; D004176:Dipyridamole / Q000494:pharmacology; D005088:Exocrine Glands / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1 / Q000096:biosynthesis* / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000378:metabolism; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology; D014132:Trachea / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1; D015842:Serine Proteinase Inhibitors; D010660:Phenylisopropyladenosine; D019830:Adenosine-5'-(N-ethylcarboxamide); D004176:Dipyridamole; D013806:Theophylline; D000242:Cyclic AMP; C028322:8-phenyltheophylline; D000241:Adenosine