title: Two molecular forms of gonadotropin-releasing hormone (GnRH-I and GnRH-II) are expressed by two separate populations of cells in the rhesus macaque hypothalamus.
abstract: Gonadotropin-releasing hormone represents the primary neuroendocrine link between the brain and the reproductive axis, and at least two distinct molecular forms of this decapeptide (GnRH-I and GnRH-II) are known to be expressed in the forebrain of rhesus macaques (Macaca mulatta). Although the distribution pattern of the two corresponding mRNAs is largely dissimilar, their expression appears to show some overlap in specific regions of the hypothalamus; this raises the possibility that some cells express both molecular forms of GnRH. To resolve this issue, double-label histochemistry was performed on hypothalamic sections from six male rhesus macaques, using a monoclonal antibody to GnRH-I and a riboprobe to monkey GnRH-II mRNA. In total, more than 2000 GnRH neurons were examined but in no instance were GnRH-I peptide and GnRH-II mRNA found to be coexpressed. This finding emphasizes that GnRH-I and GnRH-II are synthesized by two distinct populations of hypothalamic neurons, and suggests that they may be regulated by different neuroendocrine pathways.
authors.affiliation: Division of Neuroscience, Oregon Regional Primate Research Center, 505 NW 185th Avenue, Beaverton, OR, USA.
authors.forename: V S
authors.initials: VS
authors.lastname: Latimer
authors.forename: S M
authors.initials: SM
authors.lastname: Rodrigues
authors.forename: V T
authors.initials: VT
authors.lastname: Garyfallou
authors.forename: S G
authors.initials: SG
authors.lastname: Kohama
authors.forename: R B
authors.initials: RB
authors.lastname: White
authors.forename: R D
authors.initials: RD
authors.lastname: Fernald
authors.forename: H F
authors.initials: HF
authors.lastname: Urbanski
mesh_terms: D000818:Animals; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000096:biosynthesis; D007031:Hypothalamus / Q000737:chemistry / Q000378:metabolism*; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008253:Macaca mulatta; D008297:Male; D020033:Protein Isoforms / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D007987:Gonadotropin-Releasing Hormone; C047717:LHRH, His(5)-Trp(7)-Tyr(8)-