title: Enteroendocrine profile of α-transducin immunoreactive cells in the gastrointestinal tract of the European sea bass (Dicentrarchus labrax).
abstract: In vertebrates, chemosensitivity of nutrients occurs through the activation of taste receptors coupled with G-protein subunits, including α-transducin (G(αtran)) and α-gustducin (G(αgust)). This study was aimed at characterising the cells expressing G(αtran) immunoreactivity throughout the mucosa of the sea bass gastrointestinal tract. G(αtran) immunoreactive cells were mainly found in the stomach, and a lower number of immunopositive cells were detected in the intestine. Some G(αtran) immunoreactive cells in the stomach contained G(αgust) immunoreactivity. Gastric G(αtran) immunoreactive cells co-expressed ghrelin, obestatin and 5-hydroxytryptamine immunoreactivity. In contrast, G(αtran) immunopositive cells did not contain somatostatin, gastrin/cholecystokinin, glucagon-like peptide-1, substance P or calcitonin gene-related peptide immunoreactivity in any investigated segments of the sea bass gastrointestinal tract. Specificity of G(αtran) and G(αgust) antisera was determined by Western blot analysis, which identified two bands at the theoretical molecular weight of ~45 and ~40 kDa, respectively, in sea bass gut tissue as well as in positive tissue, and by immunoblocking with the respective peptide, which prevented immunostaining. The results of the present study provide a molecular and morphological basis for a role of taste-related molecules in chemosensing in the sea bass gastrointestinal tract.
authors.affiliation: Department of Veterinary Medical Science, University of Bologna, via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia, Bologna, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: Latorre
authors.forename: Maurizio
authors.initials: M
authors.lastname: Mazzoni
authors.forename: Roberto
authors.initials: R
authors.lastname: De Giorgio
authors.forename: Claudia
authors.initials: C
authors.lastname: Vallorani
authors.forename: Alessio
authors.initials: A
authors.lastname: Bonaldo
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Gatta
authors.forename: Roberto
authors.initials: R
authors.lastname: Corinaldesi
authors.forename: Eugenio
authors.initials: E
authors.lastname: Ruggeri
authors.forename: Chiara
authors.initials: C
authors.lastname: Bernardini
authors.forename: Roberto
authors.initials: R
authors.lastname: Chiocchetti
authors.forename: Catia
authors.initials: C
authors.lastname: Sternini
authors.forename: Paolo
authors.initials: P
authors.lastname: Clavenzani
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D001492:Bass / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000378:metabolism*; D015293:Transducin / Q000378:metabolism*
chemical_list: D015293:Transducin