title: The orexin system in the enteric nervous system of the bottlenose dolphin (Tursiops truncatus).
abstract: This study provides a general approach to the presence and possible role of orexins and their receptors in the gut (three gastric chambers and intestine) of confined environment bottlenose dolphin. The expression of prepro-orexin, orexin A and B and orexin 1 and 2 receptors were investigated by single immunostaining and western blot analysis. The co-localization of vasoactive intestinal peptide and orexin 1 receptor in the enteric nervous system was examined by double immunostaining. Also, orexin A concentration were measured in plasma samples to assess the possible diurnal variation of the plasma level of peptide in this species. Our results showed that the orexin system is widely distributed in bottlenose dolphin enteric nervous system of the all gastrointestinal tract examined. They are very peculiar and partially differs from that of terrestrial mammals. Orexin peptides and prepro-orexin were expressed in the main stomach, pyloric stomach and proximal intestine; while orexin receptors were expressed in the all examined tracts, with the exception of main stomach where found no evidence of orexin 2 receptor. Co-localization of vasoactive intestinal peptide and orexin 1 receptor were more evident in the pyloric stomach and proximal intestine. These data could suggest a possible role of orexin system on the contractility of bottlenose dolphin gastrointestinal districts. Finally, in agreement with several reports, bottlenose dolphin orexin A plasma level was higher in the morning during fasting. Our results emphasize some common features between bottlenose dolphin and terrestrial mammals. Certainly, further functional investigations may help to better explain the role of the orexin system in the energy balance of bottlenose dolphin and the complex interaction between feeding and digestive physiology.
authors.affiliation: Department of Veterinary Medicine and Animal Productions, University of Napoli "Federico II", Napoli (NA), Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Gatta
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento (BN), Italy.
authors.forename: Finizia
authors.initials: F
authors.lastname: Russo
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento (BN), Italy.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Russolillo
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento (BN), Italy.
authors.forename: Ettore
authors.initials: E
authors.lastname: Varricchio
authors.affiliation: Department of Sciences and Technologies, University of Sannio, Benevento (BN), Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Paolucci
authors.affiliation: Department of Veterinary Medicine and Animal Productions, University of Napoli "Federico II", Napoli (NA), Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Castaldo
authors.affiliation: Department of Veterinary Medicine and Animal Productions, University of Napoli "Federico II", Napoli (NA), Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Lucini
authors.affiliation: Department of Veterinary Medicine and Animal Productions, University of Napoli "Federico II", Napoli (NA), Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: de Girolamo
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro (PD), Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Cozzi
authors.affiliation: Department of Veterinary Medicine and Animal Productions, University of Napoli "Federico II", Napoli (NA), Italy.
authors.forename: Lucianna
authors.initials: L
authors.lastname: Maruccio
mesh_terms: D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000378:metabolism*; D004289:Dolphins / Q000378:metabolism*; D017615:Enteric Nervous System / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D009479:Neuropeptides / Q000378:metabolism*; D000068797:Orexins
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins