Estrous cycle influences the expression of neuronal nitric oxide synthase in the hypothalamus and limbic system of female mice.

Full Abstract

BACKGROUND: Nitric oxide plays an important role in the regulation of male and female sexual behavior in rodents, and the expression of the nitric oxide synthase (NOS) is influenced by testosterone in the male rat, and by estrogens in the female. We have here quantitatively investigated the distribution of nNOS immunoreactive (ir) neurons in the limbic hypothalamic region of intact female mice sacrificed during different phases of estrous cycle. RESULTS: Changes were observed in the medial preoptic area (MPA) (significantly higher number in estrus) and in the arcuate nucleus (Arc) (significantly higher number in proestrus). In the ventrolateral part of the ventromedial nucleus (VMHvl) and in the bed nucleus of the stria terminalis (BST) no significant changes have been observed. In addition, by comparing males and females, we observed a stable sex dimorphism (males have a higher number of nNOS-ir cells in comparison to almost all the different phases of the estrous cycle) in the VMHvl and in the BST (when considering only the less intensely stained elements). In the MPA and in the Arc sex differences were detected only comparing some phases of the cycle. CONCLUSION: These data demonstrate that, in mice, the expression of nNOS in some hypothalamic regions involved in the control of reproduction and characterized by a large number of estrogen receptors is under the control of gonadal hormones and may vary according to the rapid variations of hormonal levels that take place during the estrous cycle.

Author information

Author/s: Sica, Monica (M); Martini, Mariangela (M); Viglietti-Panzica, Carla (C); Panzica, GianCarlo (G);

Affiliation: University of Torino, Department of Anatomy, Pharmacology and Forensic Medicine, Neuroscience Institute of Turin (NIT), Laboratory of Neuroendocrinology, Torino, Italy. msica(-atsign-)dr-knoell-consult.com

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: BMC neuroscience (BMC Neurosci), published in England. (Language: eng)

Reference: 2009-; vol 10 (issue ) : pp 78

Dates: Created 2009/07/29; Completed 2009/08/19;

PMID: 19604366, status: MEDLINE (last retrieval date: 8/21/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.