title: Regulation of body temperature by thyrotropin-releasing hormone in neonatal chicks.
abstract: To understand thermal regulation of neonatal chicks, the contribution of thyrotropin-releasing hormone (TRH), a key regulator of the hypothalamus-pituitary-thyroid axis, was investigated. Intracerebroventricular (i.c.v.) injection of TRH (5 and 20 microg) increased body temperature, but did not change plasma T3 and T4 concentrations. Intraperitoneal (i.p.) injection of triiodothyronine (T3) and thyroxine (T4) did not influence body temperature. Thereafter, the relationships between TRH and the hypothalamus-pituitary-adrenal axis and sympathetic nervous system were further investigated. Central TRH stimulated both corticosterone and epinephrine release. The i.c.v. injection of a corticotropin-releasing factor receptor antagonist attenuated the change in body temperature and corticosterone concentration caused by TRH, but did not influence plasma T3 and T4 concentrations. The i.p. injection of epinephrine did not induce hyperthermia. Therefore, the thermoregulatory response to TRH may differ in neonatal stages being dependent upon the stimulation of the hypothalamus-pituitary-adrenal axis rather than the hypothalamus-pituitary-thyroid axis.
authors.affiliation: Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Iigo
authors.forename: Kôichi
authors.initials: K
authors.lastname: Ando
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tachibana
authors.forename: D Michael
authors.initials: DM
authors.lastname: Denbow
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Furuse
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000097:blood / Q000502:physiology; D001831:Body Temperature / Q000187:drug effects* / Q000502:physiology; D002645:Chickens; D003345:Corticosterone / Q000378:metabolism; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004333:Drug Administration Routes; D004347:Drug Interactions; D004837:Epinephrine / Q000378:metabolism; D007276:Injections, Intraventricular / Q000379:methods; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D013974:Thyroxine / Q000008:administration & dosage / Q000097:blood; D014284:Triiodothyronine / Q000008:administration & dosage / Q000097:blood
chemical_list: D010446:Peptide Fragments; D014284:Triiodothyronine; C104416:astressin; D013973:Thyrotropin-Releasing Hormone; D003346:Corticotropin-Releasing Hormone; D013974:Thyroxine; D003345:Corticosterone; D004837:Epinephrine