Expression of functional purinergic receptors in pulmonary neuroepithelial bodies and their role in hypoxia chemotransmission.
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.
Fu
Xiao Wen
XW
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.
Nurse
Colin A
CA
Cutz
Ernest
E
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
D058913:Purinergic Agonists; D058914:Purinergic Antagonists; D011983:Receptors, Purinergic; D012701:Serotonin; D000255:Adenosine Triphosphate