title: Effects of unilaterally microinjecting ethanol in the preoptic-anterior hypothalamic areas of rats on ovulation.
abstract: BACKGROUND
  Intragastric or intraperitoneal ethanol (EtOH) treatment inhibits reproductive functions in females and male rats. The area of the hypothalamus where these effects take place is unknown. As the participations of the preoptic-anterior hypothalamic area (POA-AHA) in regulating ovulation is asymmetric, this study aims to analyze the effects on 17β-estradiol(E2 ), progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) serum levels, the messenger ribonucleic acid (mRNA) expression of estrogen receptor alpha (ERα) and beta (ERβ), and ovulation resulting from unilaterally microinjecting water or an EtOH solution into either side of the POA-AHA.
  
  
  METHODS
  The treatment consisted of microinjecting a 8.6 μM EtOH solution into either side of the POA-AHA. The study was performed on groups of adult cyclic rats at 09.00 hours on diestrus-1, and sacrificed on diestrus-2 at 13.00, on proestrus at 09.00 or 17.00 or on estrus at 09.00 hours. Ovulation rates were assessed in rats sacrificed on estrus. Hormonal serum levels were measured using radioimmunoassay, and as a function of ERα and ERβ mRNA expression in each side of the POA-AHA by reverse transcriptase polymerase chain reaction.
  
  
  RESULTS
  EtOH treatment blocked ovulation and the preovulatory release of LH, and lowered E2 levels. Irrespective of the treated POA-AHA side, ERα mRNA expression was consistently lower in the left POA-AHA and higher on the right. EtOH treatment in the left POA-AHA decreased FSH serum levels and lowered ERβ mRNA expression. In turn, EtOH treatment on the right POA-AHA resulted in higher FSH levels and ERβ mRNA expression.
  
  
  CONCLUSIONS
  The present results show that EtOH blocks the preovulatory surge of LH on the POA-AHA. The effects of EtOH treatment of preovulatory FSH surge on the POA-AHA are asymmetric (stimulative on the right and inhibiting in the left). The effects of EtOH treatment on preovulatory LH and FSH surge could be explained by the inhibition of ERα and ERβ mRNA expression, respectively.
authors.affiliation: Laboratory of Neuroendocrinology , Biology of Reproduction Research Unit, FES Zaragoza, U.N.A.M, México City, Mexico.
authors.forename: María-Esther
authors.initials: ME
authors.lastname: Cruz
authors.forename: Esteban
authors.initials: E
authors.lastname: Olvera
authors.forename: Marian-Jesabel
authors.initials: MJ
authors.lastname: Pérez
authors.forename: Enrique-Isid
authors.initials: EI
authors.lastname: Min
authors.forename: Angélica
authors.initials: A
authors.lastname: Flores
authors.forename: Mario
authors.initials: M
authors.lastname: Cárdenas
authors.forename: Roberto
authors.initials: R
authors.lastname: Chavira
authors.forename: Roberto
authors.initials: R
authors.lastname: Domínguez
mesh_terms: D000818:Animals; D007025:Anterior Hypothalamic Nucleus / Q000187:drug effects* / Q000502:physiology; D004958:Estradiol / Q000097:blood; D047628:Estrogen Receptor alpha / Q000096:biosynthesis; D047629:Estrogen Receptor beta / Q000096:biosynthesis; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D007986:Luteinizing Hormone / Q000097:blood; D008845:Microinjections; D010060:Ovulation / Q000187:drug effects*; D011301:Preoptic Area / Q000187:drug effects* / Q000502:physiology; D011374:Progesterone / Q000097:blood; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D000431:Ethanol; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone
keywords: Estrogen Receptor Alpha mRNA Expression; Estrogen Receptor Beta mRNA Expression; Ethanol; Follicle-Stimulating Hormone, Luteinizing Hormone Surge; Preoptic-Anterior Hypothalamic Area