title: Central administration of melanin-concentrating hormone (MCH) suppresses food intake, but not locomotor activity, in the goldfish, Carassius auratus.
abstract: Melanin-concentrating hormone (MCH) is a hypothalamo-pituitary peptide, which was first identified in the salmon pituitary as a hormone affecting body color. Recently, MCH has been implicated in the regulation of feeding behavior and energy homeostasis in mammals. Despite a growing body of knowledge concerning MCH in mammals, however, there is little information about the effect of MCH on appetite and behavior in fish. The aim of the present study was to investigate the action of MCH on feeding behavior and spontaneous locomotor activity in the goldfish. We administered synthetic MCH by intracerebroventricular (ICV) injection and examined its effect on food intake and locomotor activity using an automatic monitoring system. Both types of synthetic MCH we employed, which are of fish and human origin, were effective in stimulating aggregation of melanin granules in the melanophores of goldfish scales. Cumulative food intake was significantly decreased by ICV injection of both MCHs in a dose-dependent manner. ICV injection of fish MCH at the same doses as those used for examination of food intake induced no marked changes in locomotor activity during the observation period. These results suggest that MCH influences feeding behavior, but not spontaneous locomotor activity, in the goldfish, and may exert an anorexigenic action in the goldfish brain, unlike its orexigenic action in mammals.
authors.affiliation: Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan. kmatsuda@sci.toyama-u.ac.jp
authors.forename: Kouhei
authors.initials: K
authors.lastname: Matsuda
authors.forename: Sei-Ichi
authors.initials: S
authors.lastname: Shimakura
authors.forename: Keisuke
authors.initials: K
authors.lastname: Maruyama
authors.forename: Tohru
authors.initials: T
authors.lastname: Miura
authors.forename: Minoru
authors.initials: M
authors.lastname: Uchiyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawauchi
authors.forename: Seiji
authors.initials: S
authors.lastname: Shioda
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D006054:Goldfish; D007028:Hypothalamic Hormones / Q000494:pharmacology*; D008543:Melanins / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D010907:Pituitary Hormones / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D007028:Hypothalamic Hormones; D008543:Melanins; D010907:Pituitary Hormones; C019463:melanin-concentrating hormone