title: Changes in the GnRH mRNA and GnRH receptor (GnRH-R) mRNA levels in the hypothalamic-anterior pituitary unit of anestrous ewes after infusion of GnRH into the third cerebral ventricle.
abstract: In the present paper the role of GnRH in the ultrashort loop of the negative feedback action on GnRH secretion was evaluated on the molecular level by the Real-time PCR technique. Specifically, the effect of GnRH infused into the third cerebral ventricle on the expression of GnRH and GnRH receptor (GnRH-R) genes was analyzed in the hypothalamic-pituitary unit of anestrous ewes. GnRH did not significantly affect GnRH mRNA levels in the preoptic/anterior hypothalamic area but drastically increased its level in the ventromedial hypothalamus. In addition, GnRH infusion augmented GnRH-R mRNA level in the entire hypothalamus. In the GnRH-treated animals, anterior pituitary GnRH-R mRNA level and plasma LH concentration were also elevated. The changes in GnRH mRNA and GnRH-R mRNA levels in the hypothalamus in response to treatment with GnRH suggest that GnRH acts differently on the stability of these transcripts. On the basis of presented results it seems that GnRH may affect GnRH and GnRH-R biosynthesis and, consequently, GnRH/LH release.
authors.affiliation: The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jabłonna n. Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Lopot
authors.forename: Magdalena
authors.initials: M
authors.lastname: Ciechanowska
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Malewski
authors.forename: Krystyna
authors.initials: K
authors.lastname: Mateusiak
authors.forename: Tomasz
authors.initials: T
authors.lastname: Misztal
authors.forename: Franciszek
authors.initials: F
authors.lastname: Przekop
mesh_terms: D000780:Anestrus / Q000502:physiology*; D000818:Animals; D002552:Cerebral Ventricles / Q000187:drug effects; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000096:biosynthesis*; D007031:Hypothalamus / Q000378:metabolism*; D007276:Injections, Intraventricular; D007986:Luteinizing Hormone / Q000097:blood; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D011966:Receptors, LHRH / Q000096:biosynthesis*; D012756:Sheep
chemical_list: D012333:RNA, Messenger; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone