title: Centrally administered ghrelin potently inhibits water intake induced by angiotensin II and hypovolemia in rats.
abstract: Ghrelin is a potent, centrally acting orexigenic hormone. Recently, we showed that centrally administered ghrelin is a potent antidipsogenic hormone in 24-h water deprived rats. In this study, we examined the effect of intracerebroventricular (icv) injection of ghrelin on angiotensin II (AII)-induced water intake in rats. We also examined the effects of icv injection of ghrelin on drinking induced by intraperitoneal injection of an isotonic polyethylene glycol (PEG) solution that causes isotonic hypovolemia. Water intake induced by the icv injection of AII or ip injection of PEG was significantly reduced after icv injection of ghrelin, although food intake was stimulated by the hormone. The drinking induced by AII was also inhibited by the icv administration of 4alpha-phorbol 12, 13-didecanoate, an agonist of the osmosensitive TRPV4 channel. This study showed that ghrelin is a potent antidipsogenic peptide by antagonizing general dipsogenic mechanisms including those activated by AII and hypovolemia in rats.
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Hiroki
authors.initials: H
authors.lastname: Otsubo
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Fujihara
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Ohbuchi
authors.forename: Toru
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Takei
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ueta
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000187:drug effects*; D004435:Eating / Q000187:drug effects; D054439:Ghrelin / Q000008:administration & dosage* / Q000494:pharmacology; D020896:Hypovolemia / Q000503:physiopathology*; D007276:Injections, Intraventricular; D008297:Male; D010704:Phorbols / Q000008:administration & dosage / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D050916:TRPV Cation Channels / Q000819:agonists
chemical_list: C517592:4alpha-phorbol 12,13-didecanone; D054439:Ghrelin; D010704:Phorbols; D050916:TRPV Cation Channels; C486577:Trpv4 protein, rat; C422650:ghrelin, des-n-octanoyl; D000804:Angiotensin II; D011092:Polyethylene Glycols