title: Ghrelin stimulates milk intake by affecting adult type feeding behaviour in postnatal rats.
abstract: The influence of ghrelin on feeding behaviour during infancy is unknown. To determine whether ghrelin influences milk intake in rat pups, newborn rats received a single i.p. injection of either rat ghrelin (100 microg/kg) or rabbit anti-ghrelin immunoglobulin G (100 microg/kg) every 5 days from postpartum day 5 to day 30 (P5-P30). Milk intake was then assessed by body weight gain following a 2-h suckling period. Ghrelin significantly increased weight gain relative to vehicle-injected controls in P20, P25 and P30 pups, but not in younger animals. Similarly, after 8 h of milk restriction, anti-ghrelin injections significantly decreased weight gain in P25 and P30, but not in younger pups. Interestingly, however, ghrelin did increase independent feeding in P10 and P15 pups using a paradigm in which pups consumed milk from a milk-soaked paper towel. We therefore conclude that ghrelin stimulates milk intake at an early postnatal stage, primarily by affecting adult-type feeding behaviour.
authors.affiliation: Department of Physiology, Faculty of Medical Sciences, University of Fukui, Matsuoka, Fukui, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Piao
authors.forename: H
authors.initials: H
authors.lastname: Hosoda
authors.forename: K
authors.initials: K
authors.lastname: Kangawa
authors.forename: T
authors.initials: T
authors.lastname: Murata
authors.forename: K
authors.initials: K
authors.lastname: Narita
authors.forename: T
authors.initials: T
authors.lastname: Higuchi
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000833:Animals, Suckling; D004435:Eating / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects*; D005260:Female; D054439:Ghrelin / Q000037:antagonists & inhibitors / Q000276:immunology / Q000494:pharmacology*; D007074:Immunoglobulin G / Q000494:pharmacology; D008098:Litter Size / Q000502:physiology; D008892:Milk; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D013391:Sucking Behavior / Q000187:drug effects; D015430:Weight Gain / Q000187:drug effects
chemical_list: D054439:Ghrelin; D007074:Immunoglobulin G