Fish Physiology and Biochemistry

, Volume 39, Issue 6, pp 1555–1565 | Cite as

Enteroendocrine profile of α-transducin immunoreactive cells in the gastrointestinal tract of the European sea bass (Dicentrarchus labrax)

  • Rocco Latorre
  • Maurizio Mazzoni
  • Roberto De Giorgio
  • Claudia Vallorani
  • Alessio Bonaldo
  • Pier Paolo Gatta
  • Roberto Corinaldesi
  • Eugenio Ruggeri
  • Chiara Bernardini
  • Roberto Chiocchetti
  • Catia Sternini
  • Paolo Clavenzani


In vertebrates, chemosensitivity of nutrients occurs through the activation of taste receptors coupled with G-protein subunits, including α-transducin (Gαtran) and α-gustducin (Gαgust). This study was aimed at characterising the cells expressing Gαtran immunoreactivity throughout the mucosa of the sea bass gastrointestinal tract. Gαtran immunoreactive cells were mainly found in the stomach, and a lower number of immunopositive cells were detected in the intestine. Some Gαtran immunoreactive cells in the stomach contained Gαgust immunoreactivity. Gastric Gαtran immunoreactive cells co-expressed ghrelin, obestatin and 5-hydroxytryptamine immunoreactivity. In contrast, Gαtran 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 Gαtran and Gαgust 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.


Chemosensory system Gut peptides Taste receptors Teleost 



This work was partially supported by the grants PRIN/COFIN from the Italian Ministry of University, Research and Education 2008 and 2010 (to R. De G.), and R.F.O. funds from the University of Bologna (R. De G., R.C. and P.C.). R. De G. is the recipient of research grants from Fondazione Del Monte di Bologna e Ravenna. C.S. is supported by the National Institutes of Health DK41301 (Morphology and Cell Imaging Core) and University of California Los Angeles (UCLA) Academic Senate Grant.


  1. Al-Mahrouki AA, Youson JH (1998) Immunohistochemical studies of the endocrine cells within the gastro-entero-pancreatic system of Osteoglossomorpha, an ancient teleostean group. Gen Comp Endocrinol 110(2):125–139. doi: 10.1006/gcen.1998.7070 PubMedCrossRefGoogle Scholar
  2. Barreiro-Iglesias A, Anadon R, Rodicio MC (2010) The gustatory system of lampreys. Brain Behav Evol 75:241–250. doi: 10.1159/000315151 PubMedCrossRefGoogle Scholar
  3. Barrenechea MA, Lopez J, Martinez A (1994) Regulatory peptides in gastric endocrine cells of the rainbow trout Oncorhynchus mykiss: general distribution and colocalizations. Tissue Cell 26:309–321. doi: 10.1016/0040-8166(94)90017-5 PubMedCrossRefGoogle Scholar
  4. Behrens M, Meyerhof W (2011) Gustatory and extragustatory functions of mammalian taste receptors. Physiol Behav 105:4–13. doi: 10.1016/j.physbeh.2011.02.010 PubMedCrossRefGoogle Scholar
  5. Beorlegui C, Martinez A, Sesma P (1992) Endocrine cells and nerves in the pyloric caeca and the intestine of Oncorhynchus mykiss (Teleostei): an immunocytochemical study. Gen Comp Endocrinol 86(3):483–495. doi: 10.1016/0016-6480(92)90073-S PubMedCrossRefGoogle Scholar
  6. Bermudez R, Vigliano F, Quiroga MI, Nieto JM, Bosi G, Domeneghini C (2007) Immunohistochemical study on the neuroendocrine system of the digestive tract of turbot, Scophthalmus maximus (L.), infected by Enteromyxum scophthalmi (Myxozoa). Fish Shellfish Immunol 22:252–263. doi: 10.1016/j.fsi.2006.05.006 PubMedCrossRefGoogle Scholar
  7. Bosi G, Di Giancamillo A, Arrighi S, Domeneghini C (2004) An immunohistochemical study on the neuroendocrine system in the alimentary canal of the brown trout, Salmo trutta, L., 1758. Gen Comp Endocrinol 138:166–181. doi: 10.1016/j.ygcen.2004.06.003 PubMedCrossRefGoogle Scholar
  8. Bosi G, Domeneghini C, Arrighi S, Giari L, Simoni E, Dezfuli BS (2005a) Response of the gut neuroendocrine system of Leuciscus cephalus (L.) to the presence of Pomphorhynchus laevis Muller, 1776 (Acanthocephala). Histol Histopathol 20:509–518PubMedGoogle Scholar
  9. Bosi G, Shinn AP, Giari L, Simoni E, Pironi F, Dezfuli BS (2005b) Changes in the neuromodulators of the diffuse endocrine system of the alimentary canal of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), naturally infected with Eubothrium crassum (Cestoda). J Fish Dis 28:703–711. doi: 10.1111/j.1365-2761.2005.00674.x PubMedCrossRefGoogle Scholar
  10. Caicedo A, Pereira E, Margolskee RF, Roper SD (2003) Role of the G-protein subunit alpha-gustducin in taste cell responses to bitter stimuli. J Neurosci 23(30):9947–9952PubMedGoogle Scholar
  11. Chandrashekar J, Mueller KL, Hoon MA, Adler E, Feng L, Guo W, Zuker CS, Ryba NJ (2000) T2Rs function as bitter taste receptors. Cell 100:703–711. doi: 10.1016/S0092-8674(00)80706-0 PubMedCrossRefGoogle Scholar
  12. Clavenzani P, De Giorgio R, Mazzoni M, Chiocchetti R, Barbara G, Costerbosa GL, Russo D, Sternini C (2009) Expression of α-transducin, a chemoreceptive molecule, in endocrine and non endocrine cells of the pig gastrointestinal tract. Vet Res Commun 33:S85–S87. doi: 10.1007/s11259-009-9253-0 CrossRefGoogle Scholar
  13. De Girolamo P, Lucini C, Vega JA, Andreozzi G, Coppola L, Castaldo L (1999) Co-localization of Trk neurotrophin receptors and regulatory peptides in the endocrine cells of the teleostan stomach. Anat Rec 256:219–226. doi: 10.1002/(SICI)1097-0185(19991101)256:3<219:AID-AR1>3.0.CO;2-N PubMedCrossRefGoogle Scholar
  14. Domeneghini C, Radaelli G, Arrighi S, Mascarello F, Veggetti A (2000) Neurotransmitters and putative neuromodulators in the gut of Anguilla anguilla (L.). Localizations in the enteric nervous and endocrine systems. Eur J Histochem 44:295–306PubMedGoogle Scholar
  15. Elbal MT, Lozano MT, Agulleiro B (1988) The endocrine cells in the gut of Mugil saliens Risso, 1810 (Teleostei): an immunocytochemical and ultrastructural study. Gen Comp Endocrinol 70:231–246. doi: 10.1016/0016-6480(88)90144-X PubMedCrossRefGoogle Scholar
  16. Ferrando S, Gambardella C, Bottaro M, Saroglia M, Terova G, Tagliafierro G (2009) The compensatory growth in juveniles of sea bass gastric distributive pattern of molecules regulating metabolism. Ann N Y Acad Sci 1163:389–393. doi: 10.1111/j.1749-6632.2009.04458.x PubMedCrossRefGoogle Scholar
  17. Fujita Y, Wideman RD, Speck M, Asadi A, King DS, Webber TD, Haneda M, Kieffer TJ (2009) Incretin release from gut is acutely enhanced by sugar but not by sweeteners in vivo. Am J Physiol Endocrinol Metab 296(3):E473–E479. doi: 10.1152/ajpendo.90636.2008 PubMedCrossRefGoogle Scholar
  18. Groff KE, Youson JH (1997) An immunohistochemical study of the endocrine cells within the pancreas, intestine, and stomach of the gar (Lepisosteus osseus L.). Gen Comp Endocrinol 106:1–16. doi: 10.1006/gcen.1996.6842 PubMedCrossRefGoogle Scholar
  19. Hass N, Schwarzenbacher K, Breer H (2007) A cluster of gustducin-expressing cells in the mouse stomach associated with two distinct populations of enteroendocrine cells. Histochem Cell Biol 128:457–471. doi: 10.1007/s00418-007-0325-3 PubMedCrossRefGoogle Scholar
  20. He W, Danilova V, Zou S, Hellekant G, Margolskee RF, Damak S (2002) Partial rescue of taste response of alpha-gustducin null mice by transgenic expression of alpha-transducin. Chem Senses 27(8):719–727. doi: 10.1093/chemse/27.8.719 PubMedCrossRefGoogle Scholar
  21. Höfer D, Drenckhahn D (1998) Identification of the taste cell G-protein, alpha-gustducin, in brush cells of the rat pancreatic duct system. Histochem Cell Biol 110:303–309. doi: 10.1007/s004180050292 PubMedCrossRefGoogle Scholar
  22. Höfer D, Puschel P, Drenckhahn D (1996) Taste receptor-like cells in the rat gut identified by expression of α-gustducin. Proc Natl Acad Sci USA 93:6631–6634. doi: 10.1073/pnas.93.13.6631 PubMedCrossRefGoogle Scholar
  23. Höfer D, Asan E, Drenckhahn D (1999) Chemosensory perception in the gut. News Physiol Sci 14:18–23PubMedGoogle Scholar
  24. Holmgren S (1985) Neuropeptide functions in the fish gut. Peptides 6:363–368. doi: 10.1016/0196-9781(85)90398-5 PubMedCrossRefGoogle Scholar
  25. Holmgren S, Vaillant C, Dimaline R (1982) VIP-, substance P-, gastrin/CCK-, bombesin-, somatostatin- and glucagon-like immunoreactivities in the gut of the rainbow trout, Salmo gairdneri. Cell Tissue Res 223:141–153. doi: 10.1007/BF00221505 PubMedCrossRefGoogle Scholar
  26. Hoon MA, Adler E, Lindemeier J, Battey JF, Ryba NJ, Zuker CS (1999) Putative mammalian taste receptors: a class of taste specific GPCRs with distinct topographic selectivity. Cell 96:541–551. doi: 10.1016/S0092-8674(00)80658-3 PubMedCrossRefGoogle Scholar
  27. Ishimaru Y (2009) Molecular mechanisms of taste transduction in vertebrates. Odontology 97:1–7. doi: 10.1007/s10266-008-0095-y PubMedCrossRefGoogle Scholar
  28. Ishimaru Y, Okada S, Naito H, Nagai T, Yasuoka A, Matsumoto I, Abe K (2005) Two families of candidate taste receptors in fishes. Mech Dev 122:1310–1321. doi: 10.1016/j.mod.2005.07.005 PubMedCrossRefGoogle Scholar
  29. Janssen S, Laermans J, Verhulst PJ, Thijs T, Tack J, Depoortere I (2011) Bitter taste receptors and α-gustducin regulate the secretion of ghrelin with functional effects on food intake and gastric emptying. Proc Natl Acad Sci USA 108:2094–2099. doi: 10.1073/pnas.1011508108 PubMedCrossRefGoogle Scholar
  30. Ku SK, Lee JH, Lee HS (2004) Immunohistochemical study on the endocrine cells in the gut of the stomachless teleost, Zacco platypus (Ciprinidae). Anat Histol Embryol 33:212–219. doi: 10.1111/j.1439-0264.2004.00539.x PubMedCrossRefGoogle Scholar
  31. Kusakabe Y, Yamaguchi E, Tanemura K, Kameyama K, Chiba N, Arai S, Emori Y, Abe K (1998) Identification of two alpha- subunit species of GTP-binding proteins, Galpha15 and Galphaq, expressed in rat taste buds. Biochim Biophys Acta 1403(3):265–272. doi: 10.1016/S0167-4889(98)00062-7 PubMedCrossRefGoogle Scholar
  32. Lindemann B (2001) Receptors and transduction in taste. Nature 413:219–225. doi: 10.1038/35093032 PubMedCrossRefGoogle Scholar
  33. Manning AJ, Murray HM, Gallant JW, Matsuoka MP, Radford E, Douglas SE (2008) Ontogenetic and tissue-specific expression of preproghrelin in the Atlantic halibut, Hippoglossus hippoglossus L. J Endocrinol 196:181–192. doi: 10.1677/JOE-07-0517 PubMedCrossRefGoogle Scholar
  34. Margolskee RF (2002) Molecular mechanisms of bitter and sweet taste transduction. J Biol Chem 277:1–4. doi: 10.1074/jbc.R100054200 PubMedCrossRefGoogle Scholar
  35. Mazzoni M, De Giorgio R, Latorre R, Vallorani C, Bosi P, Trevisi P, Barbara G, Stanghellini V, Corinaldesi R, Forni M, Faussone Pellegrini MS, Sternini C, Clavenzani P (2013) Expression and regulation of α-transducin in the pig gastrointestinal tract. J Cell Mol Med 17:466–474. doi: 10.1111/jcmm.12026 Google Scholar
  36. McLaughlin SK, McKinnon PJ, Margolskee RF (1992) Gustducin is a taste-cell-specific G protein closely related to the transducins. Nature 357:563–569. doi: 10.1038/357563a0 PubMedCrossRefGoogle Scholar
  37. Ming D, Ninomiya Y, Margolskee RF (1999) Blocking taste receptor activation of gustducin inhibits gustatory responses to bitter compounds. Proc Natl Acad Sci USA 96:9903–9908. doi: 10.1073/pnas.96.17.9903 PubMedCrossRefGoogle Scholar
  38. Moran AW, Al-Rammahi MA, Arora DK, Batchelor DJ, Coulter EA, Daly K, Ionescu C, Bravo D, Shirazi-Beechey SP (2010) Expression of Na +/glucose co-transporter 1 (SGLT1) is enhanced by supplementation of the diet of weaning piglets with artificial sweeteners. Br J Nutr 104:637–646. doi: 10.1017/S0007114510000917 PubMedCrossRefGoogle Scholar
  39. Muradov H, Kerov V, Boyd KK, Artemyev NO (2008) Unique transducins expressed in long and short photoreceptors of lamprey Petromyzon marinus. Vis Res 48(21):2302–2308. doi: 10.1016/j.visres.2008.07.006 PubMedCrossRefGoogle Scholar
  40. Nelson LE, Sheridan MA (2006) Gastroenteropancreatic hormones and metabolism in fish. Gen Comp Endocrinol 148:116–124. doi: 10.1016/j.ygcen.2006.01.011 PubMedCrossRefGoogle Scholar
  41. Nelson G, Hoon MA, Chandrashekar J, Zhang Y, Ryba NJ, Zuker CS (2001) Mammalian sweet taste receptors. Cell 106:381–390. doi: 10.1016/S0092-8674(01)00451-2 PubMedCrossRefGoogle Scholar
  42. Nelson G, Chandrashekar J, Hoon MA, Feng L, Zhao G, Ryba NJ, Zuker CS (2002) An amino-acid taste receptor. Nature 416:199–202. doi: 10.1038/nature726 PubMedCrossRefGoogle Scholar
  43. Ohmoto M, Okada S, Nakamura S, Abe K, Matsumoto I (2011) Mutually exclusive expression of Gαia and Gα14 reveals diversification of taste receptor cells in Zebrafish. J Comp Neurol 519:1616–1629. doi: 10.1002/cne.22589 PubMedCrossRefGoogle Scholar
  44. Oike H, Nagai T, Furuyama A, Okada S, Aihara Y, Ishimaru Y, Marui T, Matsumoto I, Misaka T, Abe K (2007) Characterization of ligands for fish taste receptors. J Neurosci 27:5584–5592. doi: 10.1523/JNEUROSCI.0651-07.2007 PubMedCrossRefGoogle Scholar
  45. Oka Y, Korsching SI (2011) Shared and unique G alpha proteins in Zebrafish versus mammalian sense of taste and smell. Chem Senses 36:357–365. doi: 10.1093/chemse/bjq138 PubMedCrossRefGoogle Scholar
  46. Palmer JM, Greenwood-Van Meerveld B (2001) Integrative neuroimmunomodulation of gastrointestinal function during enteric parasitism. J Parasitol 87:483–504. doi:10.1645/0022-3395(2001)087[0483:INOGFD]2.0.CO;2PubMedGoogle Scholar
  47. Pederzoli A, Bertacchi I, Gambarelli A, Mola L (2004) Immunolocalisation of vasoactive intestinal peptide and substance P in the developing gut of Dicentrarchus labrax (L.). Eur J Histochem 48:179–184PubMedGoogle Scholar
  48. Plisetskaya EM, Mommsen TP (1996) Glucagon and glucagon-like peptides in fishes. Int Rev Cytol 168:187–257PubMedCrossRefGoogle Scholar
  49. Reinecke M, Muller C, Segner H (1997) An immunohistochemical analysis of the ontogeny, distribution and coexistence of 12 regulatory peptides and serotonin in endocrine cells and nerve fibers of the digestive tract of the turbot, Scophthalmus maximus (Teleostei). Anat Embryol (Berl) 195:87–101. doi: 10.1007/s004290050028 CrossRefGoogle Scholar
  50. Rozengurt N, Wu SV, Chen MC, Huang C, Sternini C, Rozengurt E (2006) Colocalization of the alpha-subunit of gustducin with PYY and GLP-1 in L cells of human colon. Am J Physiol Gastrointest Liver Physiol 291:G792–G802. doi: 10.1152/ajpgi.00074.2006 PubMedCrossRefGoogle Scholar
  51. Ruiz-Avila L, McLaughlin SK, Wildman D, McKinnon PJ, Robichon A, Spickofsky N, Margolskee RF (1995) Coupling of bitter receptor to phosphodiesterase through transducin in taste receptor cells. Nature 376:80–85. doi: 10.1038/376080a0 PubMedCrossRefGoogle Scholar
  52. Sainz E, Cavenagh MM, Gutierrez J, Battey JF, Northup JK, Sullivan SL (2007) Functional characterization of human bitter taste receptors. Biochem J 403:537–543. doi: 10.1042/BJ20061744 PubMedCrossRefGoogle Scholar
  53. Sarwal MM, Sontag JM, Hoang L, Brenner S, Wilkie TM (1996) G protein alpha subunit multigene family in the Japanese puffer fish Fugu rubripes: PCR from a compact vertebrate genome. Genome Res 6:1207–1215. doi: 10.1101/gr.6.12.1207 PubMedCrossRefGoogle Scholar
  54. Steinert RE, Gerspach AC, Gutmann H, Asarian L, Drewe J, Beglinger C (2011) The functional involvement of gut-expressed sweet taste receptors in glucose-stimulated secretion of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). Clin Nutr 30:524–532. doi: 10.1016/j.clnu.2011.01.007 PubMedCrossRefGoogle Scholar
  55. Sternini C (2007) Taste receptors in the gastrointestinal tract. IV. Functional implications of bitter taste receptors in gastrointestinal chemosensing. Am J Physiol Gastrointest Liver Physiol 292:G457–G461. doi: 10.1152/ajpgi.00411.2006 PubMedCrossRefGoogle Scholar
  56. Sternini C, Anselmi L, Rozengurt E (2008) Enteroendocrine cells: a site of ‘taste’ in gastrointestinal chemosensing. Curr Opin Endocrinol Diabetes Obes 15:73–78. doi: 10.1097/MED.0b013e3282f43a73 PubMedCrossRefGoogle Scholar
  57. Sutherland K, Young RL, Cooper NJ, Horowitz M, Blackshaw LA (2007) Phenotypic characterization of taste cells of the mouse small intestine. Am J Physiol Gastrointest Liver Physiol 292:G1420–G1428. doi: 10.1152/ajpgi.00504.2006 PubMedCrossRefGoogle Scholar
  58. Takechi R, Galloway S, Pallebage-Gamarallage MM, Johnsen RD, Mamo JC (2008) Three-dimensional immunofluorescent double labelling using polyclonal antibodies derived from the same species: enterocytic colocalization of chylomicrons with Golgi apparatus. Histochem Cell Biol 129:779–784. doi: 10.1007/s00418-008-0404-0 PubMedCrossRefGoogle Scholar
  59. Terova G, Rimoldi S, Bernardini G, Gornati R, Saroglia M (2008) Sea bass ghrelin: molecular cloning and mRNA quantification during fasting and refeeding. Gen Comp Endocrinol 155:341–351. doi: 10.1016/j.ygcen.2007.05.028 PubMedCrossRefGoogle Scholar
  60. Visus IG, Abad ME, Garcia Hernández MP, Agulleiro B (1996) Occurrence of somatostatin and insulin immunoreactivities in the stomach of sea bass (Dicentrarchus labrax L.): light and electron microscopic studies. Gen Comp Endocrinol 102:16–27. doi: 10.1006/gcen.1996.0041 PubMedCrossRefGoogle Scholar
  61. Wong GT, Gannon KS, Margolskee RF (1996) Transduction of bitter and sweet taste by gustducin. Nature 381:796–800. doi: 10.1038/381796a0 PubMedCrossRefGoogle Scholar
  62. Wu SV, Rozengurt N, Yang M, Young SH, Sinnett-Smith J, Rozengurt E (2002) Expression of bitter taste receptors of the T2R family in the gastrointestinal tract and enteroendocrine STC-1 cells. Proc Natl Acad Sci USA 99:2392–2397. doi: 10.1073/pnas.042617699 PubMedCrossRefGoogle Scholar
  63. Yasuoka A, Abe K (2009) Gustation in fish: search for prototype of taste perception. Results Probl Cell Differ 47:239–255. doi: 10.1007/400_2008_6 PubMedCrossRefGoogle Scholar
  64. Yeung CM, Chan CB, Woo NY, Cheng CH (2006) Seabream ghrelin: cDNA cloning, genomic organization and promoter studies. J Endocrinol 189:365–379. doi: 10.1677/joe.1.06593 PubMedCrossRefGoogle Scholar
  65. Zhang JV, Ren PG, Avsian-Kretchmer O, Luo CW, Rauch R, Klein C, Hsueh AJ (2005) Obestatin, a peptide encoded by the ghrelin gene, opposes ghrelin’s effects on food intake. Science 310:996–999. doi: 10.1126/science.1117255 PubMedCrossRefGoogle Scholar
  66. Zhang G, Deng S, Zhang H, Li H, Li L (2006) Distribution of different taste buds and expression of alpha gustducin in the barbles of yellow catfish (Pelteobagrus fulvidraco). Fish Physiol Biochem 32:55–62. doi: 10.1007/s10695-006-6937-z PubMedCrossRefGoogle Scholar
  67. Zhao GQ, Zhang Y, Hoon MA, Chandrashekar J, Erlenbach I, Ryba NJ, Zuker CS (2003) The receptors for mammalian sweet and umami taste. Cell 115:255–266. doi: 10.1016/S0092-8674(03)00844-4 PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Rocco Latorre
    • 1
  • Maurizio Mazzoni
    • 1
  • Roberto De Giorgio
    • 2
  • Claudia Vallorani
    • 1
  • Alessio Bonaldo
    • 1
  • Pier Paolo Gatta
    • 1
  • Roberto Corinaldesi
    • 2
  • Eugenio Ruggeri
    • 2
  • Chiara Bernardini
    • 1
  • Roberto Chiocchetti
    • 1
  • Catia Sternini
    • 3
    • 4
    • 5
  • Paolo Clavenzani
    • 1
  1. 1.Department of Veterinary Medical ScienceUniversity of BolognaOzzano dell’Emilia, BolognaItaly
  2. 2.Department of Medical and Surgical Sciences, St.Orsola-Malpighi HospitalUniversity of BolognaBolognaItaly
  3. 3.CURE/DDRC, Division of Digestive Diseases, Department of MedicineUCLALos AngelesUSA
  4. 4.Department of NeurobiologyUCLALos AngelesUSA
  5. 5.Veterans Administration Greater Los Angeles Health SystemLos AngelesUSA

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