HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 573/1/251    most recent jphysiol.2006.106740v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Krause, E. G. Articles by Contreras, R. J. Search for Related Content PubMed PubMed Citation Articles by Krause, E. G. Articles by Contreras, R. J. Related Collections Integrative

¹ Department of Psychology, Program in Neuroscience, Florida State University, Tallahassee, FL 32303-1270, USA

Studies from our laboratory and others show that oestrogen reduces angiotensin II (Ang II)-induced water intake by ovariectomized rats. Elimination of endogenous oestrogen by ovariectomy causes weight gain that can be reversed or prevented by oestrogen replacement. Changes in body weight modify cardiovascular responses to Ang II but whether such changes have similar effects on central and behavioural responses to Ang II is unknown. The goal of this study was to evaluate the contributions of oestrogen and weight loss to isoproterenol (isoprenaline; Iso)-induced Fos immunoreactivity (IR) and to angiotensin type 1 (AT1) receptor mRNA in forebrain regions implicated in the control of fluid balance. Isoproterenol significantly increased Fos IR in the hypothalamic paraventricular and supraoptic nuclei, the subfornical organ (SFO), and the organum vasculosum of the lamina terminalis, but had no effect on AT1 mRNA expression. However, both Iso-induced Fos IR and the AT1 mRNA were attenuated in the SFO of the oestrogen and weight loss groups compared with that of the control group. Consequently, we examined the effect of weight loss on Iso-induced water intake and plasma renin activity (PRA) and found that weight loss decreased water intake after Iso, but had no effect on PRA. Thus, we propose that weight loss decreases Ang II-elicited water intake in the female rat by down-regulating the expression of the AT1 receptor.

(Received 2 February 2006; accepted after revision 13 March 2006; first published online 16 March 2006)
Corresponding author R. J. Contreras: Department of Psychology, Program in Neuroscience, Florida State University, Tallahassee, FL 32303-1270, USA. Email: contreras{at}psy.fsu.edu

This article has been cited by other articles:

				A. S. Mecawi, A. Lepletier, I. G. Araujo, F. V. Fonseca, and L. C. Reis Oestrogenic influence on brain AT1 receptor signalling on the thirst and sodium appetite in osmotically stimulated and sodium-depleted female rats Exp Physiol, August 1, 2008; 93(8): 1002 - 1010. [Abstract] [Full Text] [PDF]

				E. G. Krause, K. S. Curtis, J. P. Markle, and R. J. Contreras Oestrogen affects the cardiovascular and central responses to isoproterenol of female rats J. Physiol., July 1, 2007; 582(1): 435 - 447. [Abstract] [Full Text] [PDF]