| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
(Hypertension. 2003;42:600.)
© 2003 American Heart Association, Inc.
Scientific Contributions |
From the Department of Medicine, University of Virginia School of Medicine, Charlottesville.
Correspondence to Helmy M. Siragy, MD, Department of Internal Medicine, Box 801409, University of Virginia Health System, 450 Ray C. Hunt Dr, Charlottesville, VA 22908. E-mail hms7a{at}virginia.edu
| Abstract |
|---|
|
|
|---|
Key Words: nitric oxide receptors, angiotensin II animals, transgenic receptors, bradykinin angiotensin II cyclic GMP
| Introduction |
|---|
|
|
|---|
BK, the major effector hormone of the kallikrein-kinin system, acts mainly through the BK B2-subtype (B2) receptor to mediate the majority of its cardiovascular and renal actions.7 Studies in mice that lack the B2 receptor (B2-/-) have reported normal development, blood pressure, and renal function.810 It is not known how B2-/- mice produce NO to maintain their normal blood pressures.
In the present study, we investigated whether the AT2 receptor can directly stimulate renal NO production independently of BK. Using a microdialysis technique in B2-/- and B2+/+mice, we monitored changes in the renal interstitial fluid (RIF) NO stable end products, nitrate and nitrite (NOX), and cGMP levels during low sodium intake alone and with AT1 or AT2 receptor blockade, individually or combined.
| Methods |
|---|
|
|
|---|
In Vivo Microdialysis Technique
For the determination of RIF cGMP and NOX, we constructed a microdialysis probe as previously described.2,3
In Vitro Microdialysis
In vitro best recoveries for renal NOX and cGMP were observed with a perfusion rate of 3 µL/min and were 70% for both cGMP and NOX.1,3,5
Blood Pressure Measurements
Systolic blood pressure (SBP) was measured in the tail artery in B2+/+ and B2-/-mice under restraint by using an automated sphygmomanometer.
Animal Preparation
With mice under general anesthesia, the left kidney was exposed through a left flank incision. A microdialysis probe was inserted into the outer renal cortex, as previously described,4
1 mm deep from the outer renal surface. The inflow and outflow tubes of the dialysis probe were burrowed subcutaneously and were exited near the intrascapular region. The external portions of the tubes were placed in a stainless steel spring. While the mice were still under general anesthesia, an indwelling renal interstitial infusion catheter, constructed as described previously,12 was implanted into the left renal cortex through a small hole made with a 26-gauge needle. Mice were housed under controlled conditions. Experiments were initiated at the same time each day. For collection of RIF, the inflow tube was connected to a gas-tight syringe that was filled with lactated Ringers solution and perfused at 3 µL/min.
Analytical Methods
RIF nitrate/nitrite (NOX) and cGMP levels in dialysate samples were measured with an enzyme immunoassay kit.1,3 The sensitivity was 2.0 µmol/L and 0.09 pmol/mL for NOX and cGMP,3 respectively, and the specificity was 100% for both.
Effects of Sodium Depletion and Angiotensin Receptor Blockade on RIF NOX and cGMP
RIF sample collections were performed 5 days after surgical insertion of the renal microdialysis probes. RIF samples were obtained for NOX and cGMP while the mice were consuming a normal-sodium diet. Mice were placed on a low-sodium diet for 10 days. On experimental days 6 to 10 while the animals were consuming the low-sodium diet, RIF samples were collected during renal cortical interstitial administration of 5% dextrose in water (D5W); the angiotensin AT1 receptor blocker valsartan (Novartis) at 0.5 µg /min; and the AT2 receptor blocker PD123319 (Parke-Davis) at 0.15 µg/min, individually or combined. Renal cortical interstitial infusion of each treatment was given at 3 µL/min for 4 hours on different experimental days.
Statistical Analysis of Data
Data are expressed as mean±SEM. Differences between mean values of multiple or 2 groups were analyzed by ANOVA, with subsequent Tukey honestly significant difference multiple-comparisons test. Differences of P<0.05 were considered significant.
| Results |
|---|
|
|
|---|
|
RIF NOX Response to Low Sodium Intake, PD123319, or Valsartan, Individually or Combined
During normal salt intake, there were no significant differences in RIF NOX levels between B2+/+ (4.0±0.5 µmol/L) and B2-/- (4.6±0.6 µmol/L) mice. The low salt intake increased RIF NOX levels in B2+/+ mice to 7.0±0.3 µmol/L (P<0.05). However, low salt intake did not increase RIF NOX levels in B2-/- mice (4.7±0.2 µmol/L; Figure 1).
|
AT1 receptor blockade with valsartan increased RIF NOX in B2+/+ mice to 11.9±1.4 µmol/L (P<0.0001) and in B2-/- mice to 8.34±0.5 µmol/L (P<0.0001), compared with RIF NOX levels during low salt intake. The increase in RIF NOX levels was more pronounced in B2+/+ than in B2-/- (P<0.01) mice in response to valsartan treatment. In contrast, AT2 receptor blockade with PD123319 caused a significant reduction in the RIF NOX level in the B2+/+ mice, to 3.3±0.3 µmol/L (P<0.01), and in B2-/- mice to 2.0±0.16 µmol/L (P<0.0001). Combined infusion of PD123319 and valsartan significantly decreased RIF NOX levels in both B2+/+and B2-/- mice, to 2.3±0.2 µmol/L (P<0.0001) and 2.1±0.16 µmol/L (P<0.001), respectively. There were no significant differences between RIF NOX levels during administration of PD123319 alone or during administration of combined PD123319 and valsartan.
RIF cGMP Responses to Low Sodium Intake, PD123319, and Valsartan, Individually or Combined
RIF cGMP levels increased in response to low sodium intake, from 0.31±0.07 to 0.81±0.1 pmol/mL, in B2+/+ mice (P<0.01) but did not change significantly in B2-/- mice (Figure 2). RIF cGMP values increased by >3-fold in response to administration of valsartan in the B2+/+ mice, to 2.64+0 0.6 pmol/mL (P<0.01), and in B2-/- mice, from 0.28±0.06 to 0.85±0.1 pmol/mL (P<0.0001). AT1 receptor blockade with valsartan caused a larger increase in RIF cGMP in B2+/+ than in B2-/- mice.
|
In contrast, AT2 receptor blockade with PD123319 significantly decreased RIF cGMP values in B2+/+ mice to 0.24±0.08 pmol/mL (P<0.001) and in B2-/- mice to 0.16±0.04 pmol/mL (P<0.0001). Combined infusion of PD12331 and valsartan significantly decreased RIF cGMP in both B2+/+ and B2-/- mice, to 0.22±0.05 (P<0.05) and 0.16±0.03 pmol/mL (P<0.0001), respectively. There were no significant differences between RIF cGMP levels during administration of PD alone or during combined PD123319 and valsartan treatment.
Contribution of AT1, AT2, and B2 Receptors, Individually or Combined, to Renal NOX During Low Sodium Intake
The contributions of AT1, AT2, and B2 receptors to renal levels of NO measured as the percent change from the condition in which AT1, AT2, and B2 receptors were simultaneously active in B2+/+ mice under low-salt conditions are shown in Figure 3. Data were calculated as the percentage of increase or decrease in the level of NOX for each mouse under each condition or treatment from the NOX level in wild-type mice during low salt intake. Data were averaged for each treatment to reflect the effect of blockade of each specific receptor on the renal production of NOX. AT1 receptor blockade caused a 70.3% increase in the level of NOX. Whereas solitary blockade of the AT2 receptor caused a 53% decrease in the level of NOX, the combination of AT1 and AT2 blockade caused a greater decrease, leading to a 66% decrease in the level of NOX. In contrast to blockade of the B2 receptor (ie, in B2-/- mice), which decreased NOX by 31.6%, combined blockade of AT1 and B2 receptors increased NOX by 18%. The combination of AT2 and B2 receptor blockade (PD123319 in B2-/- mice) decreased NOX production by 71%, which did not change on addition of AT1 receptor blockade to the combination of AT2 and B2 receptor blockade (69%).
|
| Discussion |
|---|
|
|
|---|
Previous studies15 demonstrated that angiotensin II, via the AT2 receptor, mediates renal production of BK, NO, and cGMP. Gohlke et al13 have shown that angiotensin II stimulates aortic cGMP in stroke-prone hypertensive rats by stimulating BK via the AT2 receptor. Tsutsumi et al14 confirmed these results by indicating that the AT2 receptor stimulates the BK-NO-cGMP cascade. However, it was unclear whether the B2 receptor is necessary for AT2 receptormediated production of NO or whether the AT2 receptor can stimulate NO production directly.
In the present study, low salt intake, a stimulus for both the renin-angiotensin system and the kallikrein-kinin system,15 failed to increase NO production in the absence of the B2 receptor. These data demonstrate the importance of B2 receptor interaction with angiotensin receptors16 during this physiologic maneuver. The interaction between the AT1 and AT2 receptors16 or the formation of a stable AT1-B2 receptor heterodimer17 might necessitate the presence of the B2 receptor to maintain the level of NO production in response to sodium restriction. During AT1 receptor blockade, angiotensin synthesis is increased because of inhibition of the short, negative-feedback loop on renin secretion, which allows for further stimulation of the AT2 receptor.18
In the current study, in the absence of the B2 receptor, direct production of NO via the AT2 receptor was exaggerated on blockade of the AT1 receptor, providing evidence that NO can be produced directly via the AT2 receptor. The contribution of AT2 receptors to the production of NO under dietary sodium restriction became evident when the AT2 receptor was blocked, leading to a significant reduction in renal tissue NO. The reductions in NO and cGMP during AT2 receptor blockade suggest that in the presence of low salt intake, the majority of NO and cGMP production is mediated via an AT2 receptor pathway.
One possibility to explain these findings is that NOX production might theoretically be stimulated by the B1 receptor in B2-/- mice. Metabolites of the kinin system might stimulate NO and cGMP production via the B1 receptor.19 However, the B1 receptor either is not expressed or is expressed only at very low levels in tissues under normal conditions, although it is induced under pathologic conditions. The B1 receptor is induced by cytokines such as interleukin-1ß, bacterial lipopolysaccharides, or vascular injury.2022 In addition, BK though potent, is short-lived and is degraded quickly in the system.23
Using a potent and specific BK B2 receptor antagonist, icatibant,24 to evaluate the role of intrarenal BK in the regulation of renal NO under conditions of a low-salt diet, we have shown that blocking the B2 receptor increases BK and decreases NO and cGMP. This dissociation elucidates that the B1 receptor does influence the production of NO2,6 in normal kidney. The combination of AT1 and AT2 receptor blockade decreased NO and cGMP. However, the levels of NO and cGMP were not significantly different from their levels during AT2 receptor blockade alone, suggesting that the AT1 receptor does not influence the production of NO and cGMP in the absence of AT2 and B2 receptors.
Our data suggest that when AT1 and B2 receptors were blocked and inactive, respectively, there was an 18% increase in renal NOX. The role of the AT2 receptor in this increase became evident when we added AT2 receptor blockade, leading to an
88% decrease in the production of NOX compared with that when only AT1 and B2 receptors were blocked or inactive. This finding suggests that NO is produced directly via the AT2 receptor. This observation is consistent with our previous study,2 which showed that combined administration of valsartan and PD123319 caused a greater decrease in renal tissue levels of NO and cGMP than did combined treatment with valsartan and icatibant. These results suggest that the AT2 receptor can directly stimulate NO in addition to its effects through the kinin system.
When the AT2 receptor was blocked, we observed a decrease in NOX production by 53.4%, and this decrease was magnified by additional blockade of the AT1 receptor (66%). This observation is consistent with previous reports17,25 that have demonstrated the interaction between AT1 and B2 receptors as an example of signal enhancement triggered by heterodimerization of 2 different, vasoactive hormone receptors. The blockade of B2 receptors led to a 31% decrease in the level of NOX. This decrease was reversed, and the level of NOX increased by 50% with the addition of AT1 blockers. These results suggest tonic inhibitory effects of AT1 on the AT2 receptor.
The maximum increase in NO production was observed on blocking the AT1 receptor, leading to a 70% increase in the level of NO, and this result suggests potentiation between AT2 and B2. Lack of this potentiation might explain the diminished cardioprotective response to inhibition of the AT1 receptor in B2-/- mice.26 The present study indicates that the AT2 receptor is capable of stimulating NO production by 2 alternative pathways: through the BK B2 receptor and by direct stimulation of NO and cGMP. These findings suggest a potential role for the AT2 receptor in the pathophysiology and management of cardiovascular diseases.
Perspectives
The primary findings of this study are as follows: (1) During ingestion of a low-salt diet, production of NO is mediated mainly through the AT2-B2 receptor cascade. (2) Blockade of the AT1 receptor enhances the production of NO through the AT2 receptor in both wild-type and B2-null mice. Our study demonstrates that NO can be produced directly through AT2 receptor stimulation. Understanding the mechanism of interaction among different receptors in the production of NO might lead to new insights into the pathophysiology and treatment of various cardiovascular disorders, such as hypertension and congestive heart failure. Human studies are required for a better understanding of the interrelations among AT1, AT2, and B2 receptors in patients with cardiovascular disorders.
| Acknowledgments |
|---|
Received June 11, 2003; first decision July 7, 2003; accepted July 29, 2003.
| References |
|---|
|
|
|---|
2. Siragy HM, de Gasparo M, Carey RM. Angiotensin type 2 receptor mediates valsartan-induced hypotension in conscious rats. Hypertension. 2000; 35: 10741077.
3. Siragy HM, Carey RM. The subtype 2 (AT2) angiotensin receptor mediates renal production of nitric oxide in conscious rats. J Clin Invest. 1997; 100: 264269.[Medline] [Order article via Infotrieve]
4. Siragy HM, Inagami T, Ichiki T, Carey RM. Sustained hypersensitivity to angiotensin II and its mechanism in mice lacking the subtype-2 (AT2) angiotensin receptor. Proc Natl Acad Sci U S A. 1999; 96: 65066510.
5. Siragy HM, Carey RM. Protective role of the angiotensin AT2 receptor in a renal wrap hypertension model. Hypertension. 1999; 33: 12371242.
6. Siragy HM, Jaffa AA, Margolius HS. Bradykinin B2 receptor modulates renal prostaglandin E2 and nitric oxide. Hypertension. 1997; 29: 757762.
7. Campbell DJ. The kallikrein-kinin system in humans. Clin Exp Pharmacol Physiol. 2001; 28: 10601065.[CrossRef][Medline] [Order article via Infotrieve]
8. Alfie ME, Yang XP, Hess F, Carretero OA. Salt-sensitive hypertension in bradykinin B2 receptor knockout mice. Biochem Biophys Res Commun. 1996; 224: 625630.[CrossRef][Medline] [Order article via Infotrieve]
9. Alfie ME, Sigmon DH, Pomposiello SI, Carretero OA. Effect of high salt intake in mutant mice lacking bradykinin B2 receptors. Hypertension. 1997; 29 (pt 2): 483487.
10. Milia AF, Gross V, Plehm R, De Silva JA Jr, Bader M, Luft FC. Normal blood pressure and renal function in mice lacking the bradykinin B2 receptor. Hypertension. 2001; 37: 14731479.
11. Borkowski JA, Ransom RW, Seabrook GR, Trumbauer M, Chen H, Hill RG, Strader CD, Hess JF. Targeted disruption of a B2 bradykinin receptor gene in mice eliminates bradykinin action in smooth muscle and neurons. J Biol Chem. 1995; 270: 1370613710.
12. Wang ZQ, Felder RA, Carey RM. Selective inhibition of the renal dopamine subtype D1Areceptor induces antinatriuresis in conscious rats. Hypertension. 1999; 33 (pt 2): 504510.
13. Gohlke P, Pees C, Unger T. AT2 receptor stimulation increases aortic cyclic GMP in SHRSP by kinin-dependent mechanisms. Hypertension. 1998; 31: 349355.
14. Tsutsumi Y, Matsubara H, Masaki H, Kurihara H, Murasawa S, Takai S, Miyazaki M, Nozawa Y, Ozono R, Nakagawa K, Miwa T, Kawada N, Mori Y, Shibasaki Y, Tanaka Y, Fujiyama S, Koyama Y, Fujiyama A, Takahashi H, Iwasaka T. Angiotensin II type 2 receptor overexpression activates the vascular kinin system and causes vasodilation J Clin Invest. 1999; 104: 925935.[Medline] [Order article via Infotrieve]
15. Siragy HM, Jaffa AA, Margolius HS, Carey RM. Renin-angiotensin system modulates renal bradykinin production. Am J Physiol. 1996; 271: R1090R1095.[Medline] [Order article via Infotrieve]
16. Abdalla S, Lother H, Abdel-tawab AM, Quitterer U. The angiotensin II AT2 receptor is an AT1 receptor antagonist. J Biol Chem. 2001; 276: 3972139726.
17. Abdalla S, Lother H, Quitterer U. AT1-receptor heterodimers show enhanced G-protein activation and altered receptor sequestration. Nature. 2000; 407: 9498.[CrossRef][Medline] [Order article via Infotrieve]
18. Carey RM, Howell NL, Jin XH, Siragy HM. Angiotensin type 2 receptormediated hypotension in angiotensin type-1 receptorblocked rats. Hypertension. 2001; 38: 12721277.
19. Agata J, Miao R, Yayama K, Chao L, Chao J. Bradykinin B1 receptor mediates inhibition of neointima formation in rat artery after balloon angioplasty. Hypertension. 2000; 36: 364370.
20. deBlois D, Bouthillier J, Marceau F. Pulse exposure to protein synthesis inhibitors enhances vascular responses to des-Arg9-bradykinin: possible role of interleukin-1. Br J Pharmacol. 1991; 103: 10571066.[Medline] [Order article via Infotrieve]
21. Bouthillier J, Deblois D, Marceau F. Studies on the induction of pharmacological responses to des-Arg9-bradykinin in vitro and in vivo. Br J Pharmacol. 1987; 92: 257264.[Medline] [Order article via Infotrieve]
22. Pruneau D, Belichard P. Induction of bradykinin B1 receptor-mediated relaxation in the isolated rabbit carotid artery. Eur J Pharmacol. 1993; 239: 6367.[CrossRef][Medline] [Order article via Infotrieve]
23. Prado GN, Taylor L, Zhou X, Ricupero D, Mierke DF, Polgar P. Mechanisms regulating the expression, self-maintenance, and signaling-function of the bradykinin B2 and B1 receptors. J Cell Physiol. 2002; 193: 275286.[CrossRef][Medline] [Order article via Infotrieve]
24. Wirth K, Hock FJ, Albus U, Linz W, Alpermann HG, Anagnostopoulos H, Henke ST, Breipohl G, König W, Knolle J, Schölkens BA. HOE 140, a new potent and long acting bradykinin-antagonist: in vivo studies. Br J Pharmacol. 1991; 102: 774777.[Medline] [Order article via Infotrieve]
25. AbdAlla S, Lother H, el Massiery A, Quitterer U. Increased AT1 receptor heterodimers in preeclampsia mediate enhanced angiotensin II responsiveness. Nat Med. 2001; 7: 10031009.[CrossRef][Medline] [Order article via Infotrieve]
26. Yang XP, Liu YH, Mehta D, Cavasin MA, Shesely E, Xu J, Liu F, Carretero OA. Diminished cardioprotective response to inhibition of angiotensin-converting enzyme and angiotensin II type 1 receptor in B2 kinin receptor gene knockout mice. Circ Res. 2001; 88: 10721079.
This article has been cited by other articles:
![]() |
M. Byku, H. Macarthur, and T. C. Westfall Nerve stimulation induced overflow of neuropeptide Y and modulation by angiotensin II in spontaneously hypertensive rats Am J Physiol Heart Circ Physiol, November 1, 2008; 295(5): H2188 - H2197. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Schindler ACE-inhibitor, AT1-receptor-antagonist, or both? A clinical pharmacologist`s perspective after publication of the results of ONTARGET Therapeutic Advances in Cardiovascular Disease, August 1, 2008; 2(4): 233 - 248. [Abstract] [PDF] |
||||
![]() |
D. C. Isbell, S. Voros, Z. Yang, J. M. DiMaria, S. S. Berr, B. A. French, F. H. Epstein, S. P. Bishop, H. Wang, R. J. Roy, et al. Interaction between bradykinin subtype 2 and angiotensin II type 2 receptors during post-MI left ventricular remodeling Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3372 - H3378. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Toda, K. Ayajiki, and T. Okamura Interaction of Endothelial Nitric Oxide and Angiotensin in the Circulation Pharmacol. Rev., March 1, 2007; 59(1): 54 - 87. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. LeFebvre, A. Shintani, T. Gebretsadik, J. R. Petro, L. J. Murphey, and N. J. Brown Bradykinin B2 Receptor Does Not Contribute to Blood Pressure Lowering during AT1 Receptor Blockade J. Pharmacol. Exp. Ther., March 1, 2007; 320(3): 1261 - 1267. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Savoia, R. M. Touyz, M. Volpe, and E. L. Schiffrin Angiotensin Type 2 Receptor in Resistance Arteries of Type 2 Diabetic Hypertensive Patients Hypertension, February 1, 2007; 49(2): 341 - 346. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. M. Carey and J. Park Role of Angiotensin Type 2 Receptors in Vasodilation of Resistance and Capacitance Vessels Hypertension, November 1, 2006; 48(5): 824 - 825. [Full Text] [PDF] |
||||
![]() |
P. M. Abadir, A. Periasamy, R. M. Carey, and H. M. Siragy Angiotensin II Type 2 Receptor-Bradykinin B2 Receptor Functional Heterodimerization Hypertension, August 1, 2006; 48(2): 316 - 322. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Shariat-Madar, F. Mahdi, M. Warnock, J. W. Homeister, S. Srikanth, Y. Krijanovski, L. J. Murphey, A. A. Jaffa, and A. H. Schmaier Bradykinin B2 receptor knockout mice are protected from thrombosis by increased nitric oxide and prostacyclin Blood, July 1, 2006; 108(1): 192 - 199. [Abstract] [Full Text] [PDF] |
||||
![]() |
C.-F. Xia, R. S. Smith Jr, B. Shen, Z.-R. Yang, C. V. Borlongan, L. Chao, and J. Chao Postischemic Brain Injury Is Exacerbated in Mice Lacking the Kinin B2 Receptor Hypertension, April 1, 2006; 47(4): 752 - 761. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. L. Pallone Microvascular Effects of Aldosterone and Angiotensin Type 2 Receptors Hypertension, May 1, 2005; 45(5): 845 - 846. [Full Text] [PDF] |
||||
![]() |
G. W. Booz Putting the Brakes on Cardiac Hypertrophy: Exploiting the NO-cGMP Counter-Regulatory System Hypertension, March 1, 2005; 45(3): 341 - 346. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Campbell, H. Krum, and M. D. Esler Losartan Increases Bradykinin Levels in Hypertensive Humans Circulation, January 25, 2005; 111(3): 315 - 320. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. J.V. McMurray, M. A. Pfeffer, K. Swedberg, and V. J. Dzau Which Inhibitor of the Renin-Angiotensin System Should Be Used in Chronic Heart Failure and Acute Myocardial Infarction? Circulation, November 16, 2004; 110(20): 3281 - 3288. [Full Text] [PDF] |
||||
![]() |
A. Benigni, D. Corna, C. Zoja, L. Longaretti, E. Gagliardini, N. Perico, T. M. Coffman, and G. Remuzzi Targeted Deletion of Angiotensin II Type 1A Receptor Does not Protect Mice from Progressive Nephropathy of Overload Proteinuria J. Am. Soc. Nephrol., October 1, 2004; 15(10): 2666 - 2674. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Kawada, K. Dennehy, G. Solis, P. Modlinger, R. Hamel, J. T. Kawada, S. Aslam, T. Moriyama, E. Imai, W. J. Welch, et al. TP receptors regulate renal hemodynamics during angiotensin II slow pressor response Am J Physiol Renal Physiol, October 1, 2004; 287(4): F753 - F759. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Johren, A. Dendorfer, and P. Dominiak Cardiovascular and renal function of angiotensin II type-2 receptors Cardiovasc Res, June 1, 2004; 62(3): 460 - 467. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Hypertension Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2003 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |