title: Effects of intracerebroventricular administration of N-acetylhistamine on body temperature in mice.
abstract: The purpose of this study was to examine the effects of intracerebroventricular (i.c.v.) administration of N-acetylhistamine on rectal temperature, histamine level, histidine decarboxylase (HDC) activity, and the turnover rate of monoamines in mice. More than 60 micrograms of N-acetylhistamine induced hypothermia. The maximum effect of hypothermia was observed 20 min after administration of N-acetylhistamine (60-120 micrograms/mouse). A significant drop in rectal temperature of 3 degrees C was induced by 120 micrograms of N-acetylhistamine. Concurrent with the appearance of hypothermia, the histamine levels were increased. However, both histamine H1 and H2 antagonists did not prevent hypothermia. The i.c.v. administration of N-acetylhistamine inhibited HDC activity, but had no effect on the turnover rates of monoamines. These data confirmed that endogenous N-acetylhistamine may be a metabolite which lacks significant physiological roles, and demonstrated that exogenous N-acetylhistamine is not a good pharmacological tool for the study of the functions of the brain histaminergic system in mammals.
authors.affiliation: Department of Pharmacology, Tohoku University School of Dentistry, Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Onodera
authors.forename: H
authors.initials: H
authors.lastname: Shinoda
authors.forename: M
authors.initials: M
authors.lastname: Imaizumi
authors.forename: E
authors.initials: E
authors.lastname: Hiraki-Sakurai
authors.forename: A
authors.initials: A
authors.lastname: Yamatodani
mesh_terms: D000818:Animals; D015306:Biogenic Monoamines / Q000378:metabolism; D001831:Body Temperature / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects; D006632:Histamine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology; D006640:Histidine Decarboxylase / Q000378:metabolism; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains
chemical_list: D015306:Biogenic Monoamines; C021606:N-acetylhistamine; D006632:Histamine; D006640:Histidine Decarboxylase