title: Estrogenic regulation of NADPH-diaphorase in the supraoptic and paraventricular nuclei under acute osmotic stress.
abstract: Estrogen receptors (ERs) α and β are involved in the regulation of the nitrergic system in the supraoptic (SON) and paraventricular (PVN) nuclei under basal conditions. In this study we have assessed whether ERs are also involved in the modulation of the nitrergic system in the SON and PVN under acute systemic hypertonic conditions. Adult ovariectomized rats received a single injection of either estradiol, a selective ERα agonist, a selective ERβ agonist, a selective ERα antagonist, a selective ERβ antagonist or vehicle. Twenty-four hours later, animals received one i.p. injection of 1.5M NaCl to induce osmotic stress and were sacrificed after two additional hours. The number of NADPH-diaphorase-positive cells in the SON and PVN was determined. Their number in the SON was not affected by NaCl administration, whereas in the four PVN subdivisions it was decreased after NaCl administration. Estradiol and the ERα agonist prevented the action of NaCl in the four subdivisions of the PVN. In contrast, the inhibition of ERα enhanced the effect of NaCl, inducing a further decrease in the number of NADPH-diaphorase-positive cells. Moreover, the ERβ agonist enhanced and the ERβ antagonist blocked the effect of NaCl on the number of NADPH-diaphorase-positive neurons in the SON and in the medial magnocellular subdivision of the PVN. These findings indicate that estradiol regulates the nitrergic system in the SON and PVN under acute osmotic stress conditions, but the effects specifically depend on the anatomical subregions and different ERs.
authors.affiliation: Universidad Nacional de Educacion a Distancia (UNED), Department of Psychobiology, Calle Juan del Rosal 10, 28040 Madrid, Spain; Instituto Cajal, CSIC, Avenida Doctor Arce 37, 28002 Madrid, Spain; University of Turin, Department of Neuroscience, Corso Massimo D'Azeglio 52, 10126 Turin, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, 10043 Orbassano, Italy. Electronic address: dada.grassi@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Grassi
authors.affiliation: Universidad Nacional de Educacion a Distancia (UNED), Department of Psychobiology, Calle Juan del Rosal 10, 28040 Madrid, Spain; Instituto Cajal, CSIC, Avenida Doctor Arce 37, 28002 Madrid, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Lagunas
authors.affiliation: Instituto Cajal, CSIC, Avenida Doctor Arce 37, 28002 Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Amorin
authors.affiliation: Universidad Nacional de Educacion a Distancia (UNED), Department of Psychobiology, Calle Juan del Rosal 10, 28040 Madrid, Spain.
authors.forename: H
authors.initials: H
authors.lastname: Pinos
authors.affiliation: University of Turin, Department of Neuroscience, Corso Massimo D'Azeglio 52, 10126 Turin, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, 10043 Orbassano, Italy.
authors.forename: G C
authors.initials: GC
authors.lastname: Panzica
authors.affiliation: Instituto Cajal, CSIC, Avenida Doctor Arce 37, 28002 Madrid, Spain.
authors.forename: L M
authors.initials: LM
authors.lastname: Garcia-Segura
authors.affiliation: Universidad Nacional de Educacion a Distancia (UNED), Department of Psychobiology, Calle Juan del Rosal 10, 28040 Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Collado
mesh_terms: D000818:Animals; D004958:Estradiol / Q000494:pharmacology / Q000502:physiology*; D047628:Estrogen Receptor alpha / Q000819:agonists / Q000037:antagonists & inhibitors; D047629:Estrogen Receptor beta / Q000819:agonists / Q000037:antagonists & inhibitors; D005260:Female; D009252:NADPH Dehydrogenase / Q000378:metabolism*; D009474:Neurons / Q000201:enzymology*; D009997:Osmotic Pressure; D010052:Ovariectomy; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological; D013495:Supraoptic Nucleus / Q000187:drug effects / Q000201:enzymology*
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004958:Estradiol; D009252:NADPH Dehydrogenase
keywords: estrogen receptor ligands; estrogen receptors; nitric oxide; paraventricular nucleus; supraoptic nucleus; water balance