Enteroendocrine profile of ?-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 ?-transducin (G(?tran)) and ?-gustducin (G(?gust)). This study was aimed at characterising the cells expressing G(?tran) immunoreactivity throughout the mucosa of the sea bass gastrointestinal tract. G(?tran) immunoreactive cells were mainly found in the stomach, and a lower number of immunopositive cells were detected in the intestine. Some G(?tran) immunoreactive cells in the stomach contained G(?gust) immunoreactivity. Gastric G(?tran) immunoreactive cells co-expressed ghrelin, obestatin and 5-hydroxytryptamine immunoreactivity. In contrast, G(?tran) 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(?tran) and G(?gust) 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.

SUBMITTER: Latorre R 

PROVIDER: S-EPMC3825768 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature