title: Progesterone-induced amplification and advancement of GnRH/LH surges are associated with changes in kisspeptin system in preoptic area of estradiol-primed female rats.
abstract: The time course effects of ovarian steroids on kisspeptin and GnRH/LH systems is not totally clarified. We investigated the temporal relationship among kisspeptin and GnRH mRNA and kisspeptin content in the preoptic area (POA), GnRH content and release in the medial basal hypothalamus (MBH) and plasma LH levels under different steroid treatments. Ovariectomized rats treated with oil (OVOO), oil plus single dose of estradiol (OVOE), oil plus single dose of progesterone (OVOP), estradiol for 3 days plus oil (OVEO) or estradiol for 3 days plus progesterone (OVEP) were hourly decapitated from 10:00 to 17:00 or had the MBH microdialyzed from 09:00 to 19:00. Estradiol and progesterone acutely increased POA kisspeptin content without altering POA kisspeptin mRNA levels. Short-term exposure to both hormones stimulated MBH GnRH content, although no GnRH/LH surges had occurred. Chronic estradiol-treatment increased both kisspeptin mRNA levels and content in the POA, demonstrating that long exposure to estradiol is required to activate the whole kisspeptin synthesis machinery. This was followed by the peak in the GnRH/LH release. In estradiol-primed rats, progesterone further increased POA kisspeptin content, amplified and advanced GnRH/LH surges, with no additional change on POA kisspeptin mRNA. The data show an estradiol-induced temporal association between kisspeptin increase in the POA and GnRH/LH surges. Interestingly, the classic action of progesterone in amplifying and accelerating the GnRH/LH surges seems to occur by a mechanism which involves POA kisspeptin system.
authors: Departamento de Morfologia, Fisiologia e Patologia Básica, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil. Electronic address: crismleite@yahoo.com.br.
authors: Cristiane M
authors: CM
authors: Leite
authors: Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors: Bruna
authors: B
authors: Kalil
authors: Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil; Departamento de Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
authors: Ernane T
authors: ET
authors: Uchôa
authors: Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors: José
authors: J
authors: Antunes-Rodrigues
authors: Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors: Lucila K L
authors: LK
authors: Elias
authors: Department of Neuroscience, Wisconsin National Primate Research Centre, University of Wisconsin, Madison, WI, USA.
authors: Jon E
authors: JE
authors: Levine
authors: Departamento de Morfologia, Fisiologia e Patologia Básica, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors: Janete A
authors: JA
authors: Anselmo-Franci
mesh_terms: D000818:Animals; D004958:Estradiol / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000187:drug effects* / Q000378:metabolism*; D006062:Gonadotropins; D007031:Hypothalamus / Q000187:drug effects; D007033:Hypothalamus, Middle / Q000187:drug effects; D059648:Kisspeptins / Q000187:drug effects / Q000378:metabolism; D007986:Luteinizing Hormone / Q000097:blood; D010052:Ovariectomy; D011301:Preoptic Area / Q000187:drug effects; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D062211:Spatio-Temporal Analysis
chemical_list: D006062:Gonadotropins; C491406:Kiss1 protein, rat; D059648:Kisspeptins; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone
keywords: Estradiol; GnRH; Gonadotropin; Hypothalamus; Kisspeptin; Progesterone