title: Characterization of melanin-concentrating hormone in chum salmon pituitaries.
abstract: Many lower vertebrates exhibit colour change in response to the background. A dual hormonal control of colour change by two antagonistic pituitary melanophorotropic hormones was first postulated in amphibia by Hogben and Slome. It is well established that the melanotropins alpha- and beta-MSH are responsible for pigment dispersion in the integumentary melanophore of lower vertebrates and that these molecules are derived from a common precursor protein, proopiocortin, by specific processing within the intermediate lobe. No evidence has been found for an antagonistic hormone in amphibia, although the existence of such a molecule in the pituitary gland of teleost fishes has long been recognized and was termed the melanophore-concentrating hormone by Enami. Early attempts to separate the two hormones proved unsuccessful. Recently, Baker and Ball re-invoked the dual hormone concept, and it has been suggested that a melanin-concentrating hormone (MCH) is synthesized in the hypothalamus of teleosts and stored and released by the neurohyphophysis. We have now isolated a novel peptide from the pituitary of the salmon (Oncorhynchus keta) possessing an antagonistic function to MSH, and we describe here its chemical and biological characteristics.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D007028:Hypothalamic Hormones; D008543:Melanins / Q000302:isolation & purification*; D009074:Melanocyte-Stimulating Hormones / Q000037:antagonists & inhibitors; D008547:Melanophores / Q000187:drug effects*; D009842:Oligopeptides / Q000032:analysis; D010902:Pituitary Gland / Q000032:analysis*; D010907:Pituitary Hormones / Q000302:isolation & purification*; D012474:Salmon / Q000502:physiology*
chemical_list: D007028:Hypothalamic Hormones; D008543:Melanins; D009842:Oligopeptides; D010907:Pituitary Hormones; C019463:melanin-concentrating hormone; D009074:Melanocyte-Stimulating Hormones