|
|
||||||||
1Department of Physiology, Tulane University Health Sciences Center, New Orleans, Louisiana; and 2Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
Submitted 28 April 2004 ; accepted in final form 7 December 2004
Transient exposure to ANG II results in the development of salt-sensitive hypertension in rats. This study was performed to determine whether a transient hypertensive episode can induce salt-sensitive hypertension in transgenic rats with inducible expression of the mouse Ren2 renin gene [strain name TGR(Cyp1a1-Ren2)]. Systolic blood pressures were measured in conscious male Cyp1a1-Ren2 rats (n = 6) during control conditions and during dietary administration of indole-3-carbinol (I3C; 0.15%, wt/wt), for 14 days. Systolic pressure increased from 135 ± 5 to 233 ± 7 mmHg by day 14. I3C administration was terminated and blood pressure returned to normal levels (137 ± 5 mmHg) within 10 days. Subsequently, the rats were placed on a high-salt diet (8% NaCl) for 10 days. Systolic pressure increased by 34 ± 2 mmHg throughout 10 days of the high-salt diet. Neither glomerular filtration rate nor renal plasma flow was altered in Cyp1a1-Ren2 rats with salt-sensitive hypertension. In a separate group of male Cyp1a1-Ren2 rats (n = 6) transiently induced with 0.15% I3C for 14 days, administration of the superoxide dismutase mimetic tempol (4-hydroxy-2,2,6,6-tetramethyl piperidinoxyl, 2 mM) attenuated the increase in systolic pressure induced by high salt. Systolic pressure increased by only 11 ± 1 mmHg throughout 8 days of a high-salt diet and tempol administration. Thus transient induction of ANG II-dependent hypertension via activation of the Cyp1a1-Ren2 transgene induces salt-sensitive hypertension in these transgenic rats. The attenuation by tempol of the high salt-induced blood pressure elevation indicates that ANG II-induced production of superoxide anion contributes to the development of salt-sensitive hypertension after transient induction of ANG II-dependent hypertension.
tempol; superoxide anion; kidney; sodium excretion; renal hemodynamics
This article has been cited by other articles:
![]() |
C. S. Wilcox and A. Pearlman Chemistry and Antihypertensive Effects of Tempol and Other Nitroxides Pharmacol. Rev., December 1, 2008; 60(4): 418 - 469. [Abstract] [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] |
||||
![]() |
M. L. Graciano, C. R. Mouton, M. E. Patterson, D. M. Seth, J. J. Mullins, and K. D. Mitchell Renal vascular and tubulointerstitial inflammation and proliferation in Cyp1a1-Ren2 transgenic rats with inducible ANG II-dependent malignant hypertension Am J Physiol Renal Physiol, June 1, 2007; 292(6): F1858 - F1866. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Ozawa, H. Kobori, Y. Suzaki, and L. G. Navar Sustained renal interstitial macrophage infiltration following chronic angiotensin II infusions Am J Physiol Renal Physiol, January 1, 2007; 292(1): F330 - F339. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. D Mitchell, S. J Bagatell, C. S Miller, C. R Mouton, D. M Seth, and J. J Mullins Genetic Clamping of Renin Gene Expression Induces Hypertension and Elevation of Intrarenal Ang II Levels of Graded Severity in Cyp1a1-Ren2 Transgenic Rats Journal of Renin-Angiotensin-Aldosterone System, June 1, 2006; 7(2): 74 - 86. [Abstract] [PDF] |
||||
![]() |
L. Kopkan and D. S. A. Majid Superoxide Contributes to Development of Salt Sensitivity and Hypertension Induced by Nitric Oxide Deficiency Hypertension, October 1, 2005; 46(4): 1026 - 1031. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |