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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

MODULATION OF THE ACTIVITY OF VASOPRESSINERGIC NEURONS BY ESTROGEN IN RATS REFED WITH NORMAL OR SODIUM-FREE FOOD AFTER FASTING

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Author(s):
Lucio-Oliveira, F. [1] ; Traslavina, G. A. A. [1] ; Borges, B. D. B. [1] ; Franci, C. R. [1]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Fisiol, BR-14049900 Ribeirao Preto, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Neuroscience; v. 284, p. 325-336, JAN 22 2015.
Web of Science Citations: 3
Abstract

Feeding increases plasma osmolality and ovarian steroids may influence the balance of fluids. Vasopressin (AVP) neurons in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) express estrogen receptor type beta (ER beta), but not estrogen receptor type alpha(ER alpha). The circum-ventricular organs express ERa and project efferent fibers to the PVN and SON. Our aim was to assess whether interactions exist between food state-related osmolality changes and the action of estrogen on AVP neuron activity and estrogen receptor expression. We assessed plasma osmolality and AVP levels; fos-coded protein (FOS)-and AVP-immuno-reactivity (-IR) and FOS-IR and ER alpha-IR in the median preoptic nucleus (MnPO) and organ vasculosum lamina terminalis (OVLT) in estrogen-primed and unprimed ovariectomized rats under the provision of ad libitum food, 48 h of fasting, and subsequent refeeding with standard chow or sodiumfree food. Refeeding with standard chow increased plasma osmolality and AVP as well as the co-expression of FOS-IR/ AVP-IR in the PVN and SON. These responses were not altered by estrogen, with the exception of the decreases in FOS-IR/AVP-IR in the lateral PVN. During refeeding, estrogen modulates only a subpopulation of AVP neurons in the lateral PVN. FOS-ER alpha co-expression in the ventral median preoptic nucleus (vMnPO) was reduced by estrogen and increased after refeeding with standard chow following fasting. It appears that estrogen may indirectly modulate the activity of AVP neurons, which are involved in the mechanism affected by hyperosmolality-induced refeeding after fasting. This indirect action of estrogen can be at least in part via ER alpha in the vMnPO. (C) 2014 IBRO. Published by Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 04/09638-9 - Neuroendocrine regulation and effects of stress on female reproduction
Grantee:Janete Aparecida Anselmo Franci
Support Opportunities: Research Projects - Thematic Grants