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BioMed Research International
Volume 2013 (2013), Article ID 346480, 9 pages
http://dx.doi.org/10.1155/2013/346480
Research Article

Rapid Nongenomic Action of Aldosterone on Protein Expressions of Hsp90(α and β) and pc-Src in Rat Kidney

1Department of Physiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
2Department of Medicine, Lerdsin General Hospital, Bangkok 10500, Thailand
3Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand

Received 11 October 2012; Revised 25 December 2012; Accepted 25 December 2012

Academic Editor: Paul Higgins

Copyright © 2013 Somchit Eiam-Ong et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Previous in vitro studies indicated that aldosterone nongenomically phosphorylates epidermal growth factor receptor (EGFR) through activation of upstream signals, heat shock protein 90β (Hsp90β), and cytosolic (c)-Src kinase. We demonstrated that aldosterone rapidly elevates EGFR phosphorylation in rat kidney. There are no in vivo data regarding renal Hsp90(α and β) and phosphorylated (p)c-Src protein expressions. The present study further investigates the expressions of these proteins. Male Wistar rats were intraperitoneally injected with normal saline solution or aldosterone (Aldo: 150 μg/kg BW). After 30 minutes, abundances and localizations of these proteins were determined. Aldosterone enhanced renal Hsp90β protein abundance ( ), but Hsp90α and pc-Src protein levels remained unaltered. Expression of Hsp90(α and β) was induced prominently in the proximal convoluted tubules (PCTs). Activation of Hsp90α was observed in vascular and outer medulla regions, whereas Hsp90β was induced in the cortex. Immunoreactivity of pc-Src was elevated in PCT with obvious staining at the luminal membrane. This in vivo study is the first to demonstrate that aldosterone nongenomically elevates Hsp90(α and β) protein expressions in rat kidney. Aldosterone had no effect on pc-Src protein levels but modulated localization. These results indicate that aldosterone regulates upstream mediators of EGFR transactivation in vivo.