title: Estrogen receptors regulate the estrous behavior induced by progestins, peptides, and prostaglandin E2.
abstract: The role of classical estrogen receptors (ERs) in priming female reproductive behavior has been studied previously; however, the participation of this receptor during activation of estrous behavior has not been extensively studied. The purpose of this work was to test the possibility that the facilitation of lordosis behavior in estrogen-primed rats by progesterone (P) and its 5α- and 5β-reduced metabolites, gonadotropin-releasing hormone (GnRH), leptin, prostaglandin E2 (PGE2) and vagino-cervical stimulation (VCS) involves interactions with classical ERs by using the selective ER modulator, tamoxifen. To further assess the role of ERs, we also explored the effects of the pure ER antagonist, ICI182780 (ICI), on estrous behavior induced by P and GnRH. Ovariectomized, estrogen-primed rats (5μg estradiol benzoate 40h earlier) were injected intraventricularly with the above-mentioned compounds, or they received VCS. All compounds and VCS effectively facilitated estrous behavior when tested at 60, 120 or 240min after infusion or application of VCS. Intraventricular infusion of tamoxifen (5μg), 30min before, significantly attenuated estrous behaviors induced in estradiol-primed rats by P, most of its 5α- and 5β-reduced metabolites, GnRH, and PGE2, but not by VCS. Although there was a trend for reduction, tamoxifen did not significantly decrease lordosis in females treated with 5β-pregnan-3,20-dione. ICI also inhibited lordosis behavior induced by P and GnRH at some testing intervals. These results suggest that activation of classical ERs participates in the triggering effects on estrous behavior induced by agents with different chemical structures that do not bind directly to ERs.
authors: Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Plaza Hidalgo S/N, Panotla, Tlaxcala 90140, México; Doctorado en Ciencias Naturales del Centro Tlaxcala en Biología de la Conducta.
authors: F J
authors: FJ
authors: Lima-Hernández
authors: Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Plaza Hidalgo S/N, Panotla, Tlaxcala 90140, México.
authors: P
authors: P
authors: Gómora-Arrati
authors: Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Plaza Hidalgo S/N, Panotla, Tlaxcala 90140, México.
authors: M
authors: M
authors: García-Juárez
authors: Neuroscience and Behavior Program, Center for Neuroendocrine Studies, Tobin Hall, University of Massachusetts, Amherst, MA 01003-9271, USA.
authors: J D
authors: JD
authors: Blaustein
authors: Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors: A M
authors: AM
authors: Etgen
authors: Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Plaza Hidalgo S/N, Panotla, Tlaxcala 90140, México.
authors: C
authors: C
authors: Beyer
authors: Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Plaza Hidalgo S/N, Panotla, Tlaxcala 90140, México. Electronic address: oglezflo@gmail.mx.
authors: O
authors: O
authors: González-Flores
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015232:Dinoprostone / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D030762:Estrous Cycle / Q000187:drug effects*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007276:Injections, Intraventricular; D020738:Leptin / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D011372:Progestins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011960:Receptors, Estrogen / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D013629:Tamoxifen / Q000494:pharmacology
chemical_list: D004965:Estrogen Antagonists; D020738:Leptin; D010455:Peptides; D011372:Progestins; D011960:Receptors, Estrogen; D013629:Tamoxifen; D007987:Gonadotropin-Releasing Hormone; D015232:Dinoprostone
keywords: ER; GnRH; Leptin; Lordosis; PGE(2); Proceptivity; Progestins; Src kinase