title: Ghrelin modulates gene and protein expression of digestive enzymes in the intestine and hepatopancreas of goldfish (Carassius auratus) via the GHS-R1a: Possible roles of PLC/PKC and AC/PKA intracellular signaling pathways.
abstract: Ghrelin, a multifunctional gut-brain hormone, is involved in the regulation of gastric functions in mammals. This study aimed to determine whether ghrelin modulates digestive enzymes in goldfish (Carassius auratus). Immunofluorescence microscopy found colocalization of ghrelin, GHS-R1a and the digestive enzymes sucrase-isomaltase, aminopeptidase A, trypsin and lipoprotein lipase in intestinal and hepatopancreatic cells. In vitro ghrelin treatment in intestinal and hepatopancreas explant culture led to a concentration- and time-dependent modulation (mainly stimulatory) of most of the digestive enzymes tested. The ghrelin-induced upregulations of digestive enzyme expression were all abolished by preincubation with the GHS-R1a ghrelin receptor antagonist [D-Lys3]-GHRP-6, and most of them by the phospholipase C inhibitor U73122 or the protein kinase A inhibitor H89. This indicates that ghrelin effects on digestive enzymes are mediated by GHS-R1a, partly by triggering the PLC/PKC and AC/PKA intracellular signaling pathways. These data suggest a role for ghrelin on digestive processes in fish.
authors.affiliation: Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada; Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain. Electronic address: ayelenmelisablanco@ucm.es.
authors.forename: Ayelén Melisa
authors.initials: AM
authors.lastname: Blanco
authors.affiliation: Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada; Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Avenida Intendente Marinos Km. 8,2, 7130 Chascomús, Buenos Aires, Argentina. Electronic address: jbertucci@intech.gov.ar.
authors.forename: Juan Ignacio
authors.initials: JI
authors.lastname: Bertucci
authors.affiliation: Department of Pharmacology and Toxicology, and Neuroscience Institute, Morehouse School of Medicine, 720 Westview Drive, GA 30310 Atlanta, GA, United States. Electronic address: asanchez@msm.edu.
authors.forename: Aída
authors.initials: A
authors.lastname: Sánchez-Bretaño
authors.affiliation: Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain. Electronic address: mjdelgad@bio.ucm.es.
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Delgado
authors.affiliation: Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain. Electronic address: aivalenciano@bio.ucm.es.
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Valenciano
authors.affiliation: Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada. Electronic address: suraj.unniappan@usask.ca.
authors.forename: Suraj
authors.initials: S
authors.lastname: Unniappan
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004963:Estrenes / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D054439:Ghrelin / Q000494:pharmacology*; D006054:Goldfish / Q000378:metabolism*; D043143:Hepatopancreas / Q000187:drug effects* / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects*; D007546:Isoquinolines / Q000494:pharmacology; D054801:Phosphoinositide Phospholipase C / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D011760:Pyrrolidinones / Q000494:pharmacology; D054440:Receptors, Ghrelin / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D004963:Estrenes; D054439:Ghrelin; D007546:Isoquinolines; D011760:Pyrrolidinones; D054440:Receptors, Ghrelin; D013449:Sulfonamides; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D054801:Phosphoinositide Phospholipase C; D000262:Adenylyl Cyclases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide
keywords: Aminopeptidase; Fish; Ghrelin; Lipoprotein lipase; Sucrase-isomaltase; Trypsin