(Hypertension. 1995;25:1232-1237.)
© 1995 American Heart Association, Inc.
Articles |
From the Department Nephrology and Hypertension, University Hospital Utrecht, Netherlands (B.B.), and the Department of Physiology, Tulane University School of Medicine, New Orleans, La.
Correspondence to K.D. Mitchell, PhD, Department of Physiology, SL 39, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112.
Abstract It has been suggested that the increased levels of angiotensin II (Ang II) in the contralateral kidney of two-kidney, one clip (2K1C) Goldblatt hypertensive rats act to enhance tubuloglomerular feedback responsiveness and proximal tubular reabsorption and thereby exert a substantial sodium-retaining influence on the nonclipped kidney. The current study investigated the Ang II dependency of tubuloglomerular feedback responsiveness in the nonclipped kidney during the early stages of development of 2K1C hypertension. Stop-flow pressure feedback responses were assessed in the nonclipped kidney of 2K1C rats during control conditions and after systemic administration of the Ang II type 1 receptor antagonist losartan (10 mg/kg). In 1-week clipped and sham-operated rats, losartan administration decreased mean arterial pressure (from 143±6 to 123±2 mm Hg, P<.01, and from 129±2 to 106±5 mm Hg, P<.01, respectively) and attenuated the magnitude of the maximal feedback responses (from -12.9±1.2 to -3.0±0.3 mm Hg, P<.01, and from -13.2±1.5 to -3.6±1.1 mm Hg, P<.01, respectively). The decreases in mean arterial pressure were not significantly different in sham-operated and 1-week clipped rats. In 3-week clipped rats, mean arterial pressure was further elevated (163±6 mm Hg) compared with sham-operated rats (134±4 mm Hg, P<.01). Although maximal tubuloglomerular feedback responses were similar in 3-week clipped and sham-operated rats, the late proximal perfusion rate eliciting a half-maximal response averaged 13±2 nL/min in the 3-week clipped and 18±1 nL/min in the sham-operated rats (P<.05), indicating enhanced tubuloglomerular feedback responsiveness in the nonclipped kidney. After losartan administration, mean arterial pressure decreased by 32±5 and 43±3 mm Hg, and the maximal tubuloglomerular feedback responses were markedly attenuated in both the sham-operated rats (from -12.3±1.9 to -2.4±0.9 mm Hg, P<.01) and clipped rats (from -9.6±0.6 to -1.8±0.5 mm Hg, P<.01). These data indicate that during the early stages of 2K1C Goldblatt hypertension, tubuloglomerular feedback responsiveness in the nonclipped kidney is maintained or slightly enhanced and highly dependent on Ang II type 1 receptor activation.
Key Words: renal circulation receptors, angiotensin hypertension, renovascular rats, Sprague-Dawley losartan
This article has been cited by other articles:
![]() |
H. Kobori, M. Nangaku, L. G. Navar, and A. Nishiyama The Intrarenal Renin-Angiotensin System: From Physiology to the Pathobiology of Hypertension and Kidney Disease Pharmacol. Rev., September 1, 2007; 59(3): 251 - 287. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. D. Mitchell and J. J. Mullins Enhanced tubuloglomerular feedback in Cyp1a1-Ren2 transgenic rats with inducible ANG II-dependent malignant hypertension Am J Physiol Renal Physiol, December 1, 2005; 289(6): F1210 - F1216. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Zhuo, J. D. Imig, T. G. Hammond, S. Orengo, E. Benes, and L. G. Navar Ang II Accumulation in Rat Renal Endosomes During Ang II-Induced Hypertension: Role of AT1 Receptor Hypertension, January 1, 2002; 39(1): 116 - 121. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Cervenka, H. J. Kramer, J. Maly, and J. Heller Role of nNOS in Regulation of Renal Function in Angiotensin II-Induced Hypertension Hypertension, August 1, 2001; 38(2): 280 - 285. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. TURKSTRA, B. BRAAM, and H. A. KOOMANS Impaired Renal Blood Flow Autoregulation in Two-Kidney, One-Clip Hypertensive Rats Is Caused by Enhanced Activity of Nitric Oxide J. Am. Soc. Nephrol., May 1, 2000; 11(5): 847 - 855. [Abstract] [Full Text] |
||||
![]() |
E. Turkstra, P. Boer, B. Braam, and H. A. Koomans Increased Availability of Nitric Oxide Leads to Enhanced Nitric Oxide Dependency of Tubuloglomerular Feedback in the Contralateral Kidney of Rats With 2-Kidney, 1-Clip Goldblatt Hypertension Hypertension, October 1, 1999; 34(4): 679 - 684. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Cervenka, C.-T. Wang, K. D. Mitchell, and L. G. Navar Proximal Tubular Angiotensin II Levels and Renal Functional Responses to AT1 Receptor Blockade in Nonclipped Kidneys of Goldblatt Hypertensive Rats Hypertension, January 1, 1999; 33(1): 102 - 107. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Zhuo, M. Ohishi, and F. A. O. Mendelsohn Roles of AT1 and AT2 Receptors in the Hypertensive Ren-2 Gene Transgenic Rat Kidney Hypertension, January 1, 1999; 33(1): 347 - 353. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Ichihara, J. D. Imig, and L. G. Navar Neuronal Nitric Oxide Synthase-Dependent Afferent Arteriolar Function in Angiotensin II-Induced Hypertension Hypertension, January 1, 1999; 33(1): 462 - 466. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. G. Navar, L. Zou, A. Von Thun, C. Tarng Wang, J. D. Imig, and K. D. Mitchell Unraveling the Mystery of Goldblatt Hypertension Physiology, August 1, 1998; 13(4): 170 - 176. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Cervenka, C.-T. Wang, and L. G. Navar Effects of acute AT1 receptor blockade by candesartan on arterial pressure and renal function in rats Am J Physiol Renal Physiol, May 1, 1998; 274(5): F940 - F945. [Abstract] [Full Text] [PDF] |
||||
![]() |
L.-X. Zou, J. D. Imig, A. M. Von Thun, A. Hymel, H. Ono, and L. G. Navar Receptor-Mediated Intrarenal Angiotensin II Augmentation in Angiotensin II–Infused Rats Hypertension, October 1, 1996; 28(4): 669 - 677. [Abstract] [Full Text] |
||||
|
Hypertension Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1995 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |