title: Elucidating the roles of gut neuropeptides on channel catfish feed intake, glycemia, and hypothalamic NPY and POMC expression.
abstract: Both intrinsic and extrinsic factors modulate food intake and glycemia in vertebrates, in part through interactions with hypothalamic neuropeptide Y (NPY) and proopiomelanocortin (POMC) neurons. The objective of this project was to elucidate the effects of ghrelin (GHRL), gastrin-releasing peptide (GRP), cholecystokinin (CCK), glucagon-like peptide (GLP), pancreatic polypeptide (PP), and peptide YY (PYY) on appetite, glycemia, and hypothalamic expression of NPY and POMC in channel catfish. Catfish were injected intraperitoneally with a single peptide at concentrations of either 0 (control), 50, 100, or 200 ng/g body weight (BW), respectively. Fish were allowed to recover for 30 min, and then fed to satiation over 1 h. Feed intake was determined 1h post-feeding. Catfish injected with GHRL at 50 and 100 ng/g BW and GRP at 200 ng/g BW consumed significantly (P<0.05) less feed compared to controls. A tendency (P<0.1) to suppress feed intake was also observed in the 200 ng/g BW GHRL and PP treatments. PYY, CCK, and GLP had no effects on feed intake. Glycemia was not affected by GHRL, GRP, PP, and PYY treatments, but was suppressed by CCK. A tendency toward lower plasma glucose concentrations was observed in fish administered GLP at 50 ng/g BW. Hypothalamic NPY expression was highly variable and not significantly affected by treatment. POMC expression was also variable, but tended to be reduced by the highest concentration of CCK. These results provide new insight into the roles and regulation of gut neuropeptides in catfish appetite and glycemia.
authors.affiliation: Center for Fisheries, Aquaculture, and Aquatic Sciences, Department of Animal Science, Food, and Nutrition, Southern Illinois University, Carbondale, IL 62901, USA.
authors.forename: Julie C
authors.initials: JC
authors.lastname: Schroeter
authors.affiliation: Center for Fisheries, Aquaculture, and Aquatic Sciences, Department of Animal Science, Food, and Nutrition, Southern Illinois University, Carbondale, IL 62901, USA.
authors.forename: Carlin M
authors.initials: CM
authors.lastname: Fenn
authors.affiliation: Center for Fisheries, Aquaculture, and Aquatic Sciences, Department of Animal Science, Food, and Nutrition, Southern Illinois University, Carbondale, IL 62901, USA. Electronic address: bcsmall@siu.edu.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Small
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002766:Cholecystokinin / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects* / Q000502:physiology; D019886:Gastrin-Releasing Peptide / Q000008:administration & dosage / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D054439:Ghrelin / Q000008:administration & dosage / Q000494:pharmacology; D004763:Glucagon-Like Peptides / Q000008:administration & dosage / Q000494:pharmacology; D007031:Hypothalamus / Q000378:metabolism; D007059:Ictaluridae / Q000097:blood / Q000235:genetics / Q000502:physiology*; D007274:Injections, Intraperitoneal; D009478:Neuropeptide Y / Q000235:genetics*; D010191:Pancreatic Polypeptide / Q000008:administration & dosage / Q000494:pharmacology; D036361:Peptide Hormones / Q000008:administration & dosage / Q000494:pharmacology*; D019894:Peptide YY / Q000008:administration & dosage / Q000494:pharmacology; D011333:Pro-Opiomelanocortin / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D001786:Blood Glucose; D054439:Ghrelin; D009478:Neuropeptide Y; D036361:Peptide Hormones; D019894:Peptide YY; D010191:Pancreatic Polypeptide; D004763:Glucagon-Like Peptides; D011333:Pro-Opiomelanocortin; D019886:Gastrin-Releasing Peptide; D002766:Cholecystokinin
keywords: Appetite; Arcuate nucleus; GI tract; Glucose