Testosterone influences renal electrolyte excretion in SHR/y and WKY males

Jonathan Toot¹^,2 , Cathy Jenkins¹^,2 , Gail Dunphy¹ , Shannon Boehme¹ , Mike Hart¹ , Amy Milsted¹ , Monte Turner¹ and Daniel Ely¹

¹Biology Department, The University of Akron, Akron, OH 44325-3908, USA

²School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA

author email corresponding author email

BMC Physiology 2008, 8:5doi:10.1186/1472-6793-8-5


Published:	26 March 2008

Abstract

Background

The Y-chromosome (Yc) and testosterone (T) increase blood pressure and may also influence renal electrolyte excretion. Therefore, the goal of this study was to determine if the Yc combined with T manipulation could influence renal Na and K excretion.

Methods

To investigate the role of the Yc and T, consomic borderline hypertensive (SHR/y) and normotensive Wistar-Kyoto (WKY) rat strains were used (15 weeks) in three T treatment groups: castrate, castrate with T implant and gonadally intact males. Urine was collected (24 hrs at 15 weeks of age) for Na and K measurements by flame photometry. RT-PCR was used to demonstrate the presence of renal androgen receptor (AR) transcripts. Plasma T and aldosterone were measured by RIA. In another experiment the androgen receptor was blocked using flutamide in the diet.

Results

Na and K excretion were decreased by T in SHR/y and WKY. AR transcripts were identified in SHR/y and WKY kidneys. Plasma aldosterone was decreased in the presence of T. Blockade of the AR resulted in a significant increase in Na excretion but not in K excretion in both SHR/y and WKY males.

Conclusion

T influences electrolyte excretion through an androgen receptor dependent mechanism. There was not a differential Yc involvement in electrolyte excretion between WKY and SHR/y males.