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: 290/6/R1608    most recent 00364.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science 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 Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Song, J. Articles by Martin, D. S. Search for Related Content PubMed PubMed Citation Articles by Song, J. Articles by Martin, D. S.

RENAL HEMODYNAMICS AND CARDIORENAL INTEGRATION

Androgens augment renal vascular responses to ANG II in New Zealand genetically hypertensive rats

Basic Biomedical Sciences, University of South Dakota, Vermillion, South Dakota

Submitted 24 May 2005 ; accepted in final form 29 January 2006

Males develop higher blood pressure than do females. This study tested the hypothesis that androgens enhance responsiveness to ANG II during the development of hypertension in New Zealand genetically hypertensive (NZGH) rats. Male NZGH rats were obtained at 5 wk of age and subjected to sham operation (Sham) or castration (Cas) then studied at three age groups: 6–7, 11–12, and 16–17 wk. Mean arterial blood pressure (MAP), heart rate (HR), and renal blood flow (RBF) measurements were recorded under Inactin anesthesia. These variables were measured after enalapril (1 mg/kg) treatment and during intravenous ANG II infusion (20, 40, and 80 ng/kg/min). Plasma testosterone was measured by ELISA. Angiotensin type 1 (AT1) receptor expression was assessed by Western blot analysis and RT-PCR. ANG II-induced MAP responses were significantly attenuated in Cas NZGH rats. At the highest ANG II dose, MAP increased by 40 ± 4% in Sham vs. 22 ± 1% in Cas NZGH rats of 16–17 wk of age. Similarly, renal vascular resistance (RVR) responses to ANG II were reduced by castration (209 ± 20% in Sham vs. 168 ± 10% in Cas NZGH rats at 16–17 wk of age). Castration also reduced MAP recorded in conscious NZGH rats of this age group. Testosterone replacement restored baseline MAP and the pressor and RVR responses to ANG II. Castration reduced testosterone concentrations markedly. Testosterone treatment restored these concentrations. Neither castration nor castration+testosterone treatment affected AT1 receptor mRNA or protein expression. Collectively, these data suggest that androgens modulate renal and systemic vascular responsiveness to ANG II, which may contribute to androgen-induced facilitation of NZGH rat hypertension.

angiotensin; sex steroids; kidney; hypertension

This article has been cited by other articles:

				T. Henriques, X. Zhang, F. B. Yiannikouris, A. Daugherty, and L. A. Cassis Androgen Increases AT1a Receptor Expression in Abdominal Aortas to Promote Angiotensin II-Induced AAAs in Apolipoprotein E-Deficient Mice Arterioscler Thromb Vasc Biol, July 1, 2008; 28(7): 1251 - 1256. [Abstract] [Full Text] [PDF]

				N. B. Ojeda, D. Grigore, and B. T. Alexander Developmental Programming of Hypertension: Insight From Animal Models of Nutritional Manipulation Hypertension, July 1, 2008; 52(1): 44 - 50. [Full Text] [PDF]

				J. C. Sullivan Sex and the renin-angiotensin system: inequality between the sexes in response to RAS stimulation and inhibition Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2008; 294(4): R1220 - R1226. [Abstract] [Full Text] [PDF]

				J. C. Sullivan, L. Semprun-Prieto, E. I. Boesen, D. M. Pollock, and J. S. Pollock Sex and sex hormones influence the development of albuminuria and renal macrophage infiltration in spontaneously hypertensive rats Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2007; 293(4): R1573 - R1579. [Abstract] [Full Text] [PDF]

				J. Song, C. K. Kost Jr., and D. S. Martin Androgens potentiate renal vascular responses to angiotensin II via amplification of the Rho kinase signaling pathway Cardiovasc Res, December 1, 2006; 72(3): 456 - 463. [Abstract] [Full Text] [PDF]