title: alpha-Gustducin immunoreactivity in the airways.
abstract: The G-protein subunit alpha-gustducin is a marker of chemoreceptive cells. In the present study, we examined the immunohistochemical localization of alpha-gustducin in rat airway epithelium both by light and electron microscopy. alpha-Gustducin immunoreactivity was found in solitary cells that presented ultrastructural features of chemoreceptor cells, i.e. flask-shaped or pear-shaped, with an apical process with thin microvilli protruding into the lumen. The immunostaining was mainly concentrated in the apical process and along the basolateral cell surface. To investigate whether alpha-gustducin-immunoreactive cells represented a distinct cell subset in rat airways, we performed double-label immunocytochemistry with antibodies to protein gene groduct (PGP) 9.5, a marker of neuroendocrine cells, and to phospholipase C beta2 (PLCbeta2), a component of the bitter signalling pathway. alpha-Gustducin-immunoreactive cells were present in a subset of PGP-9.5-immunoreactive elements, although not all alpha-gustducin-positive cells expressed PGP 9.5 labelling. In addition, a subset of alpha-gustducin-expressing cells colocalized PLCbeta2. This work thus demonstrates that solitary alpha-gustducin-immunoreactive cells exist throughout the airways and represent a specialized cell type with morphological and immunohistochemical characteristics of chemoreceptor cells.
authors.affiliation: Department of Morphological-Biomedical Sciences, Human Anatomy and Histology Section, University of Verona, Verona, Italy.
authors.forename: Flavia
authors.initials: F
authors.lastname: Merigo
authors.forename: Donatella
authors.initials: D
authors.lastname: Benati
authors.forename: Marco
authors.initials: M
authors.lastname: Tizzano
authors.forename: Francesco
authors.initials: F
authors.lastname: Osculati
authors.forename: Andrea
authors.initials: A
authors.lastname: Sbarbati
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D007830:Larynx / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D016253:Microscopy, Immunoelectron; D008871:Microvilli / Q000378:metabolism / Q000648:ultrastructure; D054799:Phospholipase C beta; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014132:Trachea / Q000378:metabolism* / Q000648:ultrastructure; D015293:Transducin / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism; D043222:Ubiquitin Thiolesterase / Q000378:metabolism
chemical_list: D015415:Biomarkers; D005456:Fluorescent Dyes; D007527:Isoenzymes; C075192:gustducin; D010738:Type C Phospholipases; D054799:Phospholipase C beta; C518038:Plcb2 protein, rat; C489034:UCHL1 protein, rat; D043222:Ubiquitin Thiolesterase; D015293:Transducin; D016650:Fluorescein-5-isothiocyanate