title: Melanin concentrating hormone (MCH) is involved in the regulation of growth hormone in Cichlasoma dimerus (Cichlidae, Teleostei).
abstract: Growth hormone (GH) is the main pituitary hormone involved in somatic growth. In fish, the neuroendocrine control of GH is multifactorial due to the interaction of multiple inhibitors and stimulators. Melanin-concentrating hormone (MCH) is a cyclic peptide involved in skin color regulation of fish. In addition, MCH has been related to the regulation of food intake in both mammals and fish. There is only one report presenting evidences on the GH release stimulation by MCH in mammals in experiments in vitro, but there are no data on non-mammals. In the present work, we report for the first time the sequence of MCH and GH cDNA in Cichlasoma dimerus, a freshwater South American cichlid fish. We detected contacts between MCH fibers and GH cells in the proximal pars distalis region of the pituitary gland by double label confocal immunofluorescence indicating a possible functional relationship. Besides, we found that MCH increased GH transcript levels and stimulated GH release in pituitary cultures. Additionally, C. dimerus exposed to a white background had a greater number of MCH neurons with a larger nuclear area and higher levels of MCH transcript than those fish exposed to a black background. Furthermore, fish reared for 3 months in a white background showed a greater body weight and total length compared to those from black background suggesting that MCH might be related to somatic growth in C. dimerus. Our results report for the first time, that MCH is involved in the regulation of the synthesis and release of GH in vitro in C. dimerus, and probably in the fish growth rate.
authors.affiliation: Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA Buenos Aires, Argentina.
authors.forename: D I
authors.initials: DI
authors.lastname: Pérez Sirkin
authors.forename: M M
authors.initials: MM
authors.lastname: Cánepa
authors.forename: M
authors.initials: M
authors.lastname: Fossati
authors.forename: J I
authors.initials: JI
authors.lastname: Fernandino
authors.forename: T
authors.initials: T
authors.lastname: Delgadin
authors.forename: L F
authors.initials: LF
authors.lastname: Canosa
authors.forename: G M
authors.initials: GM
authors.lastname: Somoza
authors.forename: P G
authors.initials: PG
authors.lastname: Vissio
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D023681:Cichlids / Q000254:growth & development* / Q000502:physiology*; D003116:Color; D004777:Environment; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D013006:Growth Hormone / Q000235:genetics / Q000378:metabolism*; D007028:Hypothalamic Hormones / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008543:Melanins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009924:Organ Culture Techniques; D010902:Pituitary Gland / Q000254:growth & development / Q000378:metabolism*; D010907:Pituitary Hormones / Q000235:genetics / Q000378:metabolism*
chemical_list: D007028:Hypothalamic Hormones; D008543:Melanins; D010907:Pituitary Hormones; C019463:melanin-concentrating hormone; D013006:Growth Hormone