(Hypertension. 1997;30:217-221.)
© 1997 American Heart Association, Inc.
Articles |
From the Hypertension and Vascular Research Division, Heart and Vascular Institute, Henry Ford Hospital, Detroit, Mich.
Correspondence to A.G. Scicli, PhD, Hypertension and Vascular Research Division, Henry Ford Hospital, 2799 West Grand Blvd, Detroit MI 48202-2689. E-mail agscicli{at}aol.com
| Abstract |
|---|
|
|
|---|
MAP: -15±2.7 and -21±3.3
mm Hg, respectively; P<.001); this hypotension was not
affected by the angiotensin type 1 antagonist
L-158,809 (200 µg/kg IA), the angiotensin type 2
antagonist PD 123319 (10 mg/kg IA), saralasin, or sarthran
(10 µg/kg per minute). The bradykinin type 2 receptor
antagonist icatibant (30 µg per rat) eliminated the
hypotensive responses to Ang-(1-7), which now increased MAP at all
doses tested (P<.005). Thus in the presence of bradykinin,
Ang-(1-7) induces hypotensive responses that are blocked by icatibant
and unaffected by angiotensin receptor
antagonists. Ang-(1-7) given to saline-infused rats
elicited hypertensive responses at all doses (
MAP: 6.4±1.5,
12±1.6, and 16.3±2.7 mm Hg, respectively; P<.01);
these responses were abolished by L-158,809 and sarthran. In rats
pretreated with saralasin, Ang-(1-7) induced hypotension at 80 and 380
nmol (
MAP: -7.7±2.3 and -9.5±2.7, respectively;
P<.05), whereas icatibant abolished this response. Thus in
the rat, Ang-(1-7) can decrease blood pressure by a mechanism involving
the bradykinin type 2 receptor and participates with bradykinin in a
vasodepressor pathway that may serve a counterregulatory role,
modulating the vasoconstrictor effects of Ang II.
Key Words: angiotensin-(1-7) rats angiotensin bradykinin blood pressure
| Introduction |
|---|
|
|
|---|
There are data suggesting an interaction between Ang-(1-7) and bradykinin and/or bradykinin receptors. In canine coronary arteries, Ang-(1-7) released NO, and this release was blunted by icatibant (Hoe 140), a bradykinin type 2 (B2) receptor antagonist.7 Pörsti et al8 reported that Ang-(1-7) induced relaxation in isolated perfused and precontracted porcine coronary arteries and that this effect was lessened by icatibant. Paula et al9 reported that Ang-(1-7) potentiated the hypotensive response to bradykinin, whereas Brosnihan et al,10 working with canine coronary arteries, found that Ang-(1-7) directly relaxed precontracted rings by a mechanism involving NO and bradykinin receptors; they postulated that it acts via a non-AT1/AT2 receptor. Somewhat different results were found by Gorelik and Scicli11 using isolated precontracted porcine coronary artery rings. They reported that Ang-(1-7) by itself at 10-9 to 10-5 mol/L was unable to induce relaxation; however, when given after bradykinin, Ang-(1-7) consistently relaxed the rings by a mechanism involving B2 receptors. Thus we hypothesize that Ang-(1-7) induces hypotension in the presence of bradykinin.
To test this hypothesis, we studied whether Ang-(1-7) can decrease blood pressure in rats when given alone or in the presence of vasodepressor amounts of bradykinin. We also evaluated the contribution of bradykinin and angiotensin receptors to the blood pressure responses induced by Ang-(1-7).
| Methods |
|---|
|
|
|---|
Angiotensin and bradykinin peptides were freshly dissolved in 0.9% saline from concentrated aliquots kept in Eppendorf vials at -70°C until used. Once thawed, the aliquot was discarded.
Surgical Procedures
All protocols were approved by the Institutional Experimental
Animal Care Committee. Male Sprague-Dawley rats (375 to 400 g)
bred at Charles River Laboratories (Wilmington, Mass) were used. Water
was given ad libitum, but food was withheld on the night preceding the
experiments. Rats were anesthetized with thiobutabarbital (125
mg/kg body wt IP). A tracheostomy was performed to facilitate
spontaneous breathing. A heparinized indwelling catheter (PE-10 fused
to PE-50) was inserted into the abdominal aorta via the left femoral
artery for direct blood pressure measurements. Two catheters (PE-10
fused to PE-50) were placed close to the root of the aorta via the
right carotid artery, one for continuous infusion and the other for
bolus injections. All drugs were dissolved in 0.9% NaCl and given as a
bolus (100 µL, followed by 100 µL of 0.9% NaCl), except for
bradykinin, saralasin, and sarthran, which were given as
intra-arterial infusions.
Arterial Blood Pressure Measurements
MAP was monitored with a solid-state strain-gauge transducer
(Gould) connected to an ink recorder (model 2200S, Gould). Changes
in blood pressure were estimated from the records by measuring
maximal changes from baseline, which was defined as the average MAP
observed during the 5 minutes preceding the bolus injection.
Experimental Protocols
Protocol 1: Blood Pressure Response to Ang-(1-7) in Rats Infused
With Bradykinin
After a 60-minute stabilization period, an
intra-arterial bolus injection of Ang-(1-7) at different
doses (20, 80, and 380 nmol per rat) was given to either saline-infused
rats or rats receiving an intra-arterial infusion of
bradykinin (5 µg/kg per minute at 50 µL/min). In the rats
receiving bradykinin, responses to Ang-(1-7) were studied beginning 15
minutes after the bradykinin infusion was begun. A minimum of 5 minutes
was allowed between bolus injections to allow reproducible responses to
Ang-(1-7). Bolus saline injections were administered
intra-arterially as controls to determine nonspecific
changes in MAP.
Protocol 2: Effects of Angiotensin and Bradykinin
Receptor Antagonists on the MAP Response to Ang-(1-7) in
Bradykinin-Treated Rats
In this protocol, we studied the influence of
angiotensin receptor antagonists and a
B2 receptor antagonist, icatibant (Hoe 140), on
the hypotensive response to bolus injections of Ang-(1-7) in rats
receiving a bradykinin infusion. The following antagonists
were studied: (1) the AT1 receptor antagonist
L-158,809 (125 µg/kg IA); (2) the AT2 receptor
antagonist PD 123319 (10 mg/kg IA) (these two
antagonists were given just before the bradykinin [or
vehicle] infusion was started); (3) the
AT1/AT2 receptor antagonist
saralasin (10 µg/kg per minute IA); (4) the
AT1/AT2 receptor antagonist
sarthran (10 µg/kg per minute IA) (these two
antagonists were given simultaneously with
bradykinin); and (5) the B2 receptor antagonist
icatibant (30 µg per rat IA), which was given 15 minutes after the
bradykinin infusion was started.
Protocol 3: Effects of Angiotensin Receptor
Antagonists on the MAP Responses to Ang-(1-7) in
Saline-Infused Rats
In this protocol, we studied the effects of
angiotensin receptor antagonists on the blood
pressure response to bolus intra-arterial injections of
Ang-(1-7) in control rats infused with saline alone, using the same
antagonists and doses as in protocol 2.
Protocol 4: Effects of a B2 Receptor
Antagonist on the Blood Pressure Response to Ang-(1-7) in
Saralasin-Treated Rats
In protocol 3, we observed that Ang-(1-7) induced hypotension in
saralasin-treated rats. In protocol 4, we studied whether this
hypotensive response would be affected by the B2 receptor
antagonist icatibant (30 µg per rat IA), which was
administered 15 minutes after the saralasin infusion was started.
The doses of the AT1 and AT1/AT2 receptor antagonists used abolished the responses to an intra-arterial Ang II bolus of 5 ng per rat, a dose that increased MAP by more than 20 mm Hg.
Statistical Analysis
Unless otherwise indicated, data are mean±SEM. Data were
analyzed by two-sample t test. When variances were
found to be unequal, we used Wilcoxon's rank sum test. This
test is analogous to the two-sample t test but is based on
the ranking of the data and does not require the equal variance and
normality assumptions of the t test. An adjusted
level
of .01 was used to determine statistical significance, since multiple
comparisons were done.
| Results |
|---|
|
|
|---|
|
|
Effects of Angiotensin and Bradykinin Receptor
Antagonists on the MAP Response to Ang-(1-7) in
Bradykinin-Treated Rats
Responses to 80 nmol Ang-(1-7) per rat, either alone or in the
presence of angiotensin receptor antagonists,
are shown in Fig 2
. The concentrations of L-158,809,
saralasin, and sarthran we used abolished the response to 5 ng Ang II
IA per rat.
|
No statistical differences were observed between responses to Ang-(1-7)
alone or in the presence of angiotensin receptor
antagonists. Although a trend toward decreased responses
was observed in the L-158,809treated rats, it did not reach
statistical significance. In the bradykinin-infused rats pretreated
with the bradykinin antagonist icatibant, Ang-(1-7) induced
only a hypertensive response, as shown in Fig 2
.
To determine whether Ang IImediated hypotensive responses could be unmasked in the presence of bradykinin and an AT1 antagonist, we tested whether Ang II (5 ng per rat IA) would also decrease MAP in rats pretreated with L-158,809 and bradykinin infusion. In saline-infused rats, Ang II increased MAP by 23.8±5.1 mm Hg. In rats treated with L-158,809 alone or in the presence of bradykinin, Ang II failed to alter blood pressure.
Effects of Angiotensin Antagonists and a
Bradykinin Receptor Antagonist on the Blood Pressure
Responses to Ang-(1-7)
Intra-arterial administration of Ang-(1-7) (20, 80,
and 380 nmol per rat) in saline-infused rats resulted in a hypertensive
response (Fig 3
, Table
). This response was not affected
by the AT2 antagonist PD 123319 but was
completely blocked by the AT1 antagonists
L-158,809 and sarthran. Ang-(1-7) induced a mild hypotensive response
in rats treated with saralasin. The data corresponding to responses to
80 nmol Ang-(1-7) per rat are shown in Fig 4
. In rats
pretreated with saralasin, icatibant abolished the hypotensive response
to Ang-(1-7) (Fig 5
).
|
|
|
| Discussion |
|---|
|
|
|---|
Treating bradykinin-infused rats with a B2 receptor antagonist eliminated the vasodepressor effects of Ang-(1-7) and converted the response induced by Ang-(1-7) from hypotension to hypertension. Thus Ang-(1-7)induced hypotension requires the presence of vasodepressor bradykinin activity.
To ascertain whether the responses we observed were specific for Ang-(1-7), in a few experiments we tested whether hypotension was also observed with Ang II, reasoning that if the hypotensive response was not selective for Ang-(1-7), we should also see it with Ang II. Since the potent vasoconstrictor effects of Ang II may conceal concomitant vasodepressor activity, we performed these studies in the presence of the AT1 antagonist L-158,809, which was not able to suppress Ang- (1-7)induced hypotension. Ang II failed to show any hypotensive response. These data suggest that Ang-(1-7) selectively induces hypotension in the presence of bradykinin.
The precise mechanisms activated by Ang-(1-7) are not clear. The fact that angiotensin receptor antagonists had no effect suggests that hypotension is not mediated by any of the known angiotensin receptors. It has been suggested that Ang-(1-7) acts via a receptor pharmacologically distinguishable from AT1 or AT2 receptor subtypes. For example, sarthran antagonized the response to Ang-(1-7) in arreflexic rats, whereas losartan and saralasin did not.3 Sarthran also blocked the direct vasorelaxant effect of Ang-(1-7) in isolated canine coronary rings, whereas an AT1 or AT2 blocker was ineffective.10 Sarthran exhibited no such ability to block the effects of Ang-(1-7) in bradykinin-treated rats in the present experiments. Mediation via nonreceptor mechanisms is possible, but it is not clear what they might be. It has been reported that Ang-(1-7) is an AT1 receptor blocker12 ; but since Ang-(1-7) induced hypotension in rats already treated with blocking doses of an AT1 antagonist, AT1 blockade cannot be involved.
It is noteworthy that sarthran ([Sar1,Thr8]-Ang II), which differs from saralasin ([Sar1,Val5,Ala8]-Ang II) with regard to both the amino acid in position 5 (Ile versus Val) and its carboxyl-terminal amino acid (Thr versus Ala), was unable to reveal a hypotensive response to Ang-(1-7). Both are considered effective AT1/AT2 antagonists. At this time we do not have an explanation for the differential effects of saralasin and sarthran; however, as mentioned above, they have been reported to affect Ang-(1-7) responses differently.3
It has been proposed that Ang-(1-7) may release bradykinin from endothelial cells,13 14 thus increasing local bradykinin concentrations. It is difficult to envisage such a mechanism as explaining the effects of Ang-(1-7) shown in this part of the study, since the rats were already receiving conspicuous amounts of bradykinin. Although we did not measure circulating bradykinin, the dose we used (5 µg/kg per minute IA) initially resulted in marked hypotension, suggesting that circulating bradykinin levels were very high. It is highly unlikely that any site could release enough bradykinin to add significantly to the already excessive kinin concentrations in the circulation.
Other studies have linked some of the pharmacological actions of angiotensin peptides to bradykinin. Seyedi et al7 reported that both Ang II and to a lesser extent Ang-(1-7) were able to release NO from canine coronary microvessels. In the study of Seyedi et al, the effects of the angiotensin peptides were also blocked by icatibant. These and other studies8 9 10 as well as the present data show a link between angiotensin peptides [particularly Ang-(1-7)] and bradykinin- and/or bradykinin receptormediated responses in vascular tissue, with aspects that appear to depend, among other things, on the experimental model and species involved.
When Ang-(1-7) was given intra-arterially to saline-infused rats, it induced hypertension. This increase in MAP was mediated by AT1 receptors, since it was opposed by an AT1 receptor antagonist and by sarthran, a nonselective angiotensin receptor blocker, but not by an AT2 antagonist. Other researchers have reported that Ang-(1-7) is a weak activator of AT1 receptors15 16 ; the present study confirms this, since hundreds of micrograms of Ang-(1-7) were needed to increase MAP by 20 mm Hg as opposed to only nanogram amounts of Ang II.
The results obtained by injection of Ang-(1-7) into saralasin-treated rats were puzzling, because we anticipated blockade of the hypertensive response; instead, Ang-(1-7) induced a small but consistent hypotensive response, which was obliterated by the B2 receptor blocker. Thus in the presence of saralasin, Ang-(1-7) elicited a mild hypotensive response, which was mediated by activation of B2 receptors and did not require exogenous bradykinin. One explanation for these results might be that Ang-(1-7) potentiated endogenous bradykinin, which would imply that activation of the renin-angiotensin system is accompanied by activation of bradykinin-dependent responses. Thus the Ang-(1-7)bradykinin/bradykinin receptor tandem would potentially act as a counterregulatory system opposing the vasoconstrictor and progrowth activities of Ang II. For this to occur, endogenous Ang-(1-7) would need to reach concentrations enabling it to exert these effects, a distinct possibility according to reported data.2 In any case, the data suggest that Ang-(1-7) can alter or propel bradykinin- and/or bradykinin receptormediated vasodepressor responses from subthreshold to above-threshold levels. It is not clear whether these responses are due to pathways similar to those involved in the response to Ang-(1-7) in the presence of excess bradykinin; however, one possibility is that excess bradykinin further potentiated responses to Ang-(1-7).
Conceptually, these data imply that when activated, the renin-angiotensin system can produce an angiotensin peptide, Ang-(1-7), that can exert a negative functional feedback on the vasoconstrictor activity of Ang II by increasing the responses to kinins (which are potent vasodilators). In addition, treatment with ACE inhibitors increases Ang-(1-7) in tissue as well as plasma17 and endothelial cells.1 Bradykinin appears to mediate a number of the cardiovascular effects of ACE inhibitors.18 19 20 Perhaps the newly found link between bradykinin and Ang-(1-7) participates in the mechanism or mechanisms whereby ACE inhibitors exert their cardiovascular effects.
The doses of Ang-(1-7) we used, as well as those used in some other studies,3 4 9 are not physiological. Responses to acute administration of a drug do not mimic the effects of prolonged and chronic changes in an endogenous compound or the effects of local (tissue) increases in concentration; however, they do demonstrate a potentially important biological effect. Further efforts should be made to elucidate its relevance.
In summary, we have shown that in thiobutabarbital-anesthetized rats, Ang-(1-7) induces hypotension when given in the presence of vasodepressor bradykinin concentrations. This hypotensive response is not significantly inhibited by an AT1, AT2, or nonselective AT1/AT2 antagonist but is completely reversed (converted back into hypertension) by icatibant, a B2 antagonist. In saline-infused rats, Ang-(1-7) induces a hypertensive response that is not affected by the AT2 antagonist PD 123319 and is blocked by an AT1 antagonist as well as the AT1/AT2 antagonist sarthran. In contrast, Ang-(1-7) induces a mild hypotensive response in saralasin-treated rats, which in turn is abolished by icatibant. These data suggest that in the rat, Ang-(1-7) participates together with bradykinin in a vasodepressor pathway. We conclude that the renin-angiotensin and kallikrein-kinin systems may be connected by an interaction between Ang-(1-7) and bradykinin- and/or bradykinin receptormediated responses.
| Selected Abbreviations and Acronyms |
|---|
|
| Acknowledgments |
|---|
Received September 18, 1996; first decision October 28, 1996; accepted January 6, 1997.
| References |
|---|
|
|
|---|
2.
Kohara K, Brosnihan KB, Chappell MC, Khosla MC,
Ferrario CM. Angiotensin-(1-7): a member of
circulating angiotensin peptides.
Hypertension. 1991;17:131-138.
3. Benter IF, Diz DI, Ferrario CM. Cardiovascular actions of angiotensin(1-7). Peptides. 1993;14:679-684.[Medline] [Order article via Infotrieve]
4.
Benter IF, Ferrario CM, Morris M, Diz DI.
Antihypertensive actions of angiotensin-(1-7) in
spontaneously hypertensive rats. Am J Physiol. 1995;269:H313-H319.
5.
Meng W, Busija DW. Comparative effects of
angiotensin-(1-7) and angiotensin II on piglet
pial arterioles. Stroke. 1993;24:2041-2044.
6. Osei SY, Ahima RS, Minkes RK, Weaver JP, Khosla MC, Kadowitz PJ. Differential responses to angiotensin-(1-7) in the feline mesenteric and hindquarters vascular beds. Eur J Pharmacol. 1993;234:35-42.[Medline] [Order article via Infotrieve]
7.
Seyedi N, Xu X, Nasjletti A, Hintze TH.
Coronary kinin generation mediates nitric oxide release after
angiotensin receptor stimulation.
Hypertension. 1995;26:164-170.
8. Pörsti I, Bara AT, Busse R, Hecker M. Release of nitric oxide by angiotensin-(1-7) from porcine coronary endothelium: implications for a novel angiotensin receptor. Br J Pharmacol. 1994;111:652-654.[Medline] [Order article via Infotrieve]
9.
Paula RD, Lima CV, Khosla MC, Santos RA.
Angiotensin-(1-7) potentiates the hypotensive effect of
bradykinin in conscious rats. Hypertension. 1995;26:1154-1159.
10.
Brosnihan KB, Li P, Ferrario CM.
Angiotensin 1-7 dilates canine coronary arteries
through kinins and nitric oxide. Hypertension. 1996;27:523-528.
11. Gorelik G, Scicli AG. Effects of angiotensin 1-7 on pig coronary artery. FASEB J. 1996;10:A18. Abstract.
12. Mahon JM, Carr RD, Nicol AK, Henderson IW. Angiotensin (1-7) is an antagonist at the type 1 angiotensin II receptor. J Hypertens. 1994;12:1377-1381.[Medline] [Order article via Infotrieve]
13. Busse R, Fleming I. Molecular responses of endothelial tissue to kinins. Diabetes. 1996;45(suppl 1):S8-S13.
14. Mombouli J-V, Vanhoutte PM. Kinins and endothelial control of vascular smooth muscle. Annu Rev Pharmacol Toxicol. 1995;35:679-705.[Medline] [Order article via Infotrieve]
15.
Ernsberger P, Zhou J, Damon TH, Douglas JG.
Angiotensin II receptor subtypes in cultured rat renal
mesangial cells. Am J Physiol. 1992;263:F411-F416.
16.
Zhou J, Ernsberger P, Douglas JG. A novel
angiotensin receptor subtype in rat mesangium: coupling to
adenylyl cyclase. Hypertension. 1993;21:1035-1038.
17.
Campbell DJ, Kladis A, Duncan A-M. Effects of
converting enzyme inhibitors on angiotensin and
bradykinin peptides. Hypertension. 1994;23:439-449.
18.
Farhy RD, Carretero OA, Ho K-L, Scicli AG. Role
of kinins and nitric oxide in the effects of angiotensin
converting enzyme inhibitors on neointima
formation. Circ Res. 1993;72:1202-1210.
19.
Liu Y-H, Yang X-P, Sharov VG, Sigmon DH, Sabbah HN,
Carretero OA. Paracrine systems in the cardioprotective effect
of angiotensin-converting enzyme inhibitors on
myocardial ischemia/reperfusion injury in rats.
Hypertension. 1996;27:7-13.
20. Linz W, Wiemer G, Schölkens BA. Role of kinins in the pathophysiology of myocardial ischemia: in vitro and in vivo studies. Diabetes. 1996;45(suppl 1):S51-S58.
This article has been cited by other articles:
![]() |
L. Anton and K. B. Brosnihan Review: Systemic and uteroplacental renin--angiotensin system in normal and pre-eclamptic pregnancies Therapeutic Advances in Cardiovascular Disease, October 1, 2008; 2(5): 349 - 362. [Abstract] [PDF] |
||||
![]() |
B. Gurzu, M. Costuleanu, S. M. Slatineanu, A. Ciobanu, and G. Petrescu Are Multiple Angiotensin Receptor Types Involved in Angiotensin (1-7) Actions on Isolated Rat Portal Vein? Journal of Renin-Angiotensin-Aldosterone System, June 1, 2005; 6(2): 90 - 95. [Abstract] [PDF] |
||||
![]() |
J. Stegbauer, V. Oberhauser, O. Vonend, and L. C. Rump Angiotensin-(1-7) modulates vascular resistance and sympathetic neurotransmission in kidneys of spontaneously hypertensive rats Cardiovasc Res, February 1, 2004; 61(2): 352 - 359. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. S. Zisman, R. S. Keller, B. Weaver, Q. Lin, R. Speth, M. R. Bristow, and C. C. Canver Increased Angiotensin-(1-7)-Forming Activity in Failing Human Heart Ventricles: Evidence for Upregulation of the Angiotensin-Converting Enzyme Homologue ACE2 Circulation, October 7, 2003; 108(14): 1707 - 1712. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. H. Schmaier The kallikrein-kinin and the renin-angiotensin systems have a multilayered interaction Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2003; 285(1): R1 - R13. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Nakamura, D. B. Averill, M. C. Chappell, D. I. Diz, K. B. Brosnihan, and C. M. Ferrario Angiotensin receptors contribute to blood pressure homeostasis in salt-depleted SHR Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2003; 284(1): R164 - R173. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Wiemer, L. W. Dobrucki, F. R. Louka, T. Malinski, and H. Heitsch AVE 0991, a Nonpeptide Mimic of the Effects of Angiotensin-(1-7) on the Endothelium Hypertension, December 1, 2002; 40(6): 847 - 852. [Abstract] [Full Text] [PDF] |
||||
![]() |
C.-C. Wei, C. M. Ferrario, K. B. Brosnihan, D. M. Farrell, W. E. Bradley, A. A. Jaffa, and L. J. Dell'Italia Angiotensin Peptides Modulate Bradykinin Levels in the Interstitium of the Dog Heart in Vivo J. Pharmacol. Exp. Ther., January 1, 2002; 300(1): 324 - 329. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Souza dos Santos, K. T. Passaglio, J. B. Pesquero, M. Bader, and A. C. Simoes e Silva Interactions Between Angiotensin-(1-7), Kinins, and Angiotensin II in Kidney and Blood Vessels Hypertension, September 1, 2001; 38(3): 660 - 664. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. J. Ferreira, R. A.S. Santos, and A. P. Almeida Angiotensin-(1-7): Cardioprotective Effect in Myocardial Ischemia/Reperfusion Hypertension, September 1, 2001; 38(3): 665 - 668. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Wilsdorf, J. V. Gainer, L. J. Murphey, D. E. Vaughan, and N. J. Brown Angiotensin-(1-7) Does Not Affect Vasodilator or TPA Responses to Bradykinin in Human Forearm Hypertension, April 1, 2001; 37(4): 1136 - 1140. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Heitsch, S. Brovkovych, T. Malinski, and G. Wiemer Angiotensin-(1-7)-Stimulated Nitric Oxide and Superoxide Release From Endothelial Cells Hypertension, January 1, 2001; 37(1): 72 - 76. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Hansen, G. Servant, T. J. Baranski, T. Fujita, T. Iiri, and S. P. Sheikh Functional Reconstitution of the Angiotensin II Type 2 Receptor and Gi Activation Circ. Res., October 27, 2000; 87(9): 753 - 759. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Ueda, S. Masumori-Maemoto, K. Ashino, T. Nagahara, E. Gotoh, S. Umemura, and M. Ishii Angiotensin-(1-7) Attenuates Vasoconstriction Evoked by Angiotensin II but Not by Noradrenaline in Man Hypertension, April 1, 2000; 35(4): 998 - 1001. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. P. Davie and J. J. V. McMurray Effect of Angiotensin-(1-7) and Bradykinin in Patients With Heart Failure Treated With an ACE Inhibitor Hypertension, September 1, 1999; 34(3): 457 - 460. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Linz, P. Wohlfart, B. A Scholkens, T. Malinski, and G. Wiemer Interactions among ACE, kinins and NO Cardiovasc Res, August 15, 1999; 43(3): 549 - 561. [Full Text] [PDF] |
||||
![]() |
A. J. M. Roks, P. P. van Geel, Y. M. Pinto, H. Buikema, R. H. Henning, D. de Zeeuw, and W. H. van Gilst Angiotensin-(1–7) Is a Modulator of the Human Renin-Angiotensin System Hypertension, August 1, 1999; 34(2): 296 - 301. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Gorelik, L. A. Carbini, and A. G. Scicli Angiotensin 1-7 Induces Bradykinin-Mediated Relaxation in Porcine Coronary Artery J. Pharmacol. Exp. Ther., July 1, 1998; 286(1): 403 - 410. [Abstract] [Full Text] |
||||
![]() |
P. Gohlke, C. Pees, and T. Unger AT2 Receptor Stimulation Increases Aortic Cyclic GMP in SHRSP by a Kinin-Dependent Mechanism Hypertension, January 1, 1998; 31(1): 349 - 355. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. N. Iyer, C. M. Ferrario, and M. C. Chappell Angiotensin-(1-7) Contributes to the Antihypertensive Effects of Blockade of the Renin-Angiotensin System Hypertension, January 1, 1998; 31(1): 356 - 361. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Hypertension Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1997 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |