Thermic and tremorogenic effects of thyroliberin (TRH) in reserpine-treated mice--the non-involvement of GABA-ergic mechanisms.
Administration of thyroliberin (TRH) to reserpinized mice causes tremor and counteracts the hypothermia in a dose-dependent fashion. The thyroliberin response is inhibited by gamma-hydroxybutyric acid (GHB) and baclofen, but not by other, more specific GABA-ergic agents, such as THIP, gamma-acetylenic GABA, and sodium valproate. Picrotoxin neither potentiates nor inhibits the thyroliberin actions. Nor are the thyroliberin effects dependent on cholinergic, monoaminergic or histaminergic mechanisms. The results repudiate a current hypothesis, that the peptide actions may be mediated by GABA-ergic pathways in the brain.
D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D001833:Body Temperature Regulation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006885:Hydroxybutyrates / Q000494:pharmacology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011956:Receptors, Cell Surface / Q000187:drug effects*; D011963:Receptors, GABA-A; D012110:Reserpine / Q000494:pharmacology*; D012978:Sodium Oxybate; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D014202:Tremor / Q000139:chemically induced*
D006885:Hydroxybutyrates; D011956:Receptors, Cell Surface; D011963:Receptors, GABA-A; D013973:Thyrotropin-Releasing Hormone; D012978:Sodium Oxybate; D012110:Reserpine; D001418:Baclofen