title: Expression of functional purinergic receptors in pulmonary neuroepithelial bodies and their role in hypoxia chemotransmission.
abstract: Adenine nucleotides act through specific cell surface receptors to invoke a variety of biological responses. Here we show that cells of neuroepithelial bodies (NEB), presumed O2 airway sensors in neonatal hamster lung, express functional P2X receptors (P2X-R). Positive immunostaining was detected in NEB cells using double-label immunohistochemistry with antibodies against P2X2 and P2X3 receptor subunits, which co-localized with serotonin (5-HT), a marker of NEB cells. For electrophysiological characterization of P2X2-R in NEB cells, fresh neonatal hamster lung slice preparation was used. Under whole-cell patch clamp, perfusion with ATP induced a concentration-dependent, non-desensitizing inward current (EC50=12 microM). Perfusion with alpha,beta-methylene ATP also induced a slow-desensitizing inward current (EC50=8.2 microM). Suramin (IC50 ca. 43 microM) and TNP-ATP (IC50 ca. 8 microM) blocked the currents evoked by both ATP and alpha,beta-methylene ATP. Using carbon fiber amperometry we observed that hypoxia and ATP induced 5-HT release from NEB cells and that this release was blocked by suramin. These data suggest that functional P2X2/3 heteromeric receptors are expressed in NEB cells. The possible function of these purinoreceptors in NEB cells could include modulation of hypoxia chemotransmission.
authors.affiliation: Division of Pathology, Department of Pediatric Laboratory Medicine, The Research Institute, The Hospital for Sick Children and University of Toronto, Toronto, Ontario M5G 1X8, Canada.
authors.forename: Xiao Wen
authors.initials: XW
authors.lastname: Fu
authors.forename: Colin A
authors.initials: CA
authors.lastname: Nurse
authors.forename: Ernest
authors.initials: E
authors.lastname: Cutz
mesh_terms: D000255:Adenosine Triphosphate / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000378:metabolism*; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D008168:Lung / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008647:Mesocricetus; D058913:Purinergic Agonists; D058914:Purinergic Antagonists; D011983:Receptors, Purinergic / Q000096:biosynthesis* / Q000502:physiology; D020545:Respiratory Mucosa / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism
chemical_list: D058913:Purinergic Agonists; D058914:Purinergic Antagonists; D011983:Receptors, Purinergic; D012701:Serotonin; D000255:Adenosine Triphosphate