Faculty Articles

Title

Divergent effects of ERα and ERβ on fluid intake by female rats are not dependent on concomitant changes in AT1R expression or body weight

Publication Title

American Journal of Physiology. Regulatory, Integrative and Comparative Physiology

Volume

311

Issue

1

Publication Date / Copyright Date

7-1-2016

First Page

14

Last Page

23

Publisher

American Physiological Society

DOI Number

10.1152/ajpregu.00102.2016

Abstract

Estradiol (E2) decreases both water and saline intakes by female rats. The ERα and ERβ subtypes are expressed in areas of the brain that control fluid intake; however, the role that these receptors play in E2's antidipsogenic and antinatriorexigenic effects have not been examined. Accordingly, we tested the hypothesis that activation of ERα and ERβ decreases water and saline intakes by female rats. We found a divergence in E2's inhibitory effect on intake: activation of ERα decreased water intake, whereas activation of ERβ decreased saline intake. E2 decreases expression of the angiotensin II type 1 receptor (AT1R), a receptor with known relevance to water and salt intakes, in multiple areas of the brain where ERα and ERβ are differentially expressed. Therefore, we tested for agonist-induced changes in AT1R mRNA expression by RT-PCR and protein expression by analyzing receptor binding to test the hypothesis that the divergent effects of these ER subtypes are mediated by region-specific changes in AT1R expression. Although we found no changes in AT1R mRNA or binding in areas of the brain known to control fluid intake associated with agonist treatment, the experimental results replicate and extend previous findings that body weight changes mediate alterations in AT1R expression in distinct brain regions. Together, the results reveal selective effects of ER subtypes on ingestive behaviors, advancing our understanding of E2's inhibitory role in the controls of fluid intake by female rats.

Disciplines

Medicine and Health Sciences | Pharmacy and Pharmaceutical Sciences

Keywords

Angiotensin II, Animals, Body Weight, Brain Chemistry, Drinking, Estradiol, Estrogen Receptor alpha, Estrogen Receptor beta, Estrogens, Female, RNA, Messenger, Rats, Rats, Long-Evans, Receptor, Angiotensin, Type 1

Peer Reviewed

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