| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1Department of Physiology and Renal and Hypertension Center, Tulane University Health Science Center, New Orleans, Louisiana; 2Division of Natural Sciences, University of California, Merced, California; and 3Department of Physiology and Biophysics, University of Buffalo, Buffalo, New York
Submitted 18 December 2006 ; accepted in final form 28 February 2007
Effects of aldosterone receptor (AR) blockade with eplerenone (epl) on renal Na+ excretion, arterial blood pressure, intra-adrenal and renal ANG II, and plasma aldosterone levels during ANG II-dependent hypertension were evaluated. Rats from one cohort (n = 10/group) 1) control, 2) control + epl (25 mg/day), 3) ANG II (60 ng/min), and 4) ANG II + epl were maintained in metabolic cages for 28 days for daily urine collections. Systolic blood pressure (SBP) was measured weekly by tail-cuff. In a second cohort (n = 12/group), daily SBP was measured by telemetry (n = 6 rats/group) 1) control, 2) ANG II, and 3) ANG II + epl. A diet containing epl (0.1%) was provided after 1 wk of ANG II infusion. Direct monitoring of BP by telemetry showed that epl delayed the onset of the increase in SBP by 2 days and slightly reduced SBP (186 ± 6 vs. 177 ± 8 mmHg). Epl transiently increased Na+ excretion within 24 h of treatment in both normo- and hypertensive rats; however, balance was reestablished within 5 days suggesting that alternative mechanisms for conserving Na+ are activated. Cortical 
-epithelial Na+ channel content (-ENaC) was not altered after 21 days of epl treatment. Epl exacerbated the ANG II-mediated increases in intrarenal ANG II (226 ± 16 vs. 365 ± 38 fmol/g) and further increased intra-adrenal ANG II (3.9 ± 0.3 vs. 8.2 ± 0.9 fmol/mg) and aldosterone (255 ± 55 vs. 710 ± 87 pmol/mg) content. Exacerbation of intrarenal ANG II levels likely contributes to the maintenance of -ENaC protein content and thus Na+ reabsorption, which helps explain the ineffectiveness of AR blockade in reducing SBP in ANG II-infused models of hypertension.
eplerenone; mineralocorticoids; sodium; spironolactone
This article has been cited by other articles:
|
|
 |
|
  M. Maliszewska-Scislo, H. Chen, R. A. Augustyniak, D. Seth, and N. F. Rossi Subfornical organ differentially modulates baroreflex function in normotensive and two-kidney, one-clip hypertensive rats Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2008; 295(3): R741 - R750. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Sun, M. Bello-Roufai, and X. Wang RNAi inhibition of mineralocorticoid receptors prevents the development of cold-induced hypertension Am J Physiol Heart Circ Physiol, April 1, 2008; 294(4): H1880 - H1887. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. C. Li and J. L. Zhuo In vivo regulation of AT1a receptor-mediated intracellular uptake of [125I]Val5-ANG II in the kidneys and adrenals of AT1a receptor-deficient mice Am J Physiol Renal Physiol, February 1, 2008; 294(2): F293 - F302. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. M. Ortiz Delineating the contributions of AT1a and AT1b receptor-mediated uptake of ANG II in kidneys and adrenals Am J Physiol Renal Physiol, February 1, 2008; 294(2): F291 - F292. [Full Text] [PDF]
|
|
|
|
|
|
R. M. Ortiz, M. L. Graciano, J. J. Mullins, and K. D. Mitchell Aldosterone receptor antagonism alleviates proteinuria, but not malignant hypertension, in Cyp1a1-Ren2 transgenic rats Am J Physiol Renal Physiol, November 1, 2007; 293(5): F1584 - F1591. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
