SciELO - Scientific Electronic Library Online

vol.31 issue9Molecular biology of the kallikrein-kinin system: from structure to functionBaroreflex control of sympathetic activity in experimental hypertension author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Brazilian Journal of Medical and Biological Research

Print version ISSN 0100-879XOn-line version ISSN 1414-431X

Braz J Med Biol Res vol. 31 no. 9 Ribeirão Preto Sept. 1998 

Braz J Med Biol Res, September 1998, Volume 31(9) 1205-1212

Antihypertensive effects of angiotensin-(1-7)

M.C. Chappell, S.N. Iyer, D.I. Diz and C.M. Ferrario

The Hypertension and Vascular Disease Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA

Correspondence and Footnotes


Accumulating evidence suggests that angiotensin-(1-7) (Ang-(1-7)) is an important component of the renin-angiotensin system and that the actions of the peptide may either contribute to or oppose those of Ang II. Ang-(1-7) can be converted directly from Ang I bypassing prerequisite formation of Ang II. Formation of Ang-(1-7) is under the control of at least three endopeptidases depending on the tissue compartment and include neprilysin, thimet oligopeptidase and prolyl oligopeptidase. Both neprilysin and thimet oligopeptidase are also involved in the metabolism of bradykinin and the atrial natriuretic peptide. Moreover, recent studies suggest that in addition to Ang I and bradykinin, Ang-(1-7) is an endogenous substrate for angiotensin converting enzyme. These enzymatic pathways may contribute to a complex relationship between the hypertensive actions of Ang II and various vasodepressor peptides from either the renin-angiotensin system or other peptide systems. Ang-(1-7) is devoid of the vasoconstrictor, central pressor, or thirst-stimulating actions associated with Ang II. In fact, new findings reveal depressor, vasodilator, and antihypertensive actions that may be more apparent in hypertensive animals or humans. Thus, Ang-(1-7) may oppose the actions of Ang II directly or as a result of increasing prostaglandins or nitric oxide. In this review, we examine the mechanisms by which Ang-(1-7) may contribute to cardiovascular regulation.

Key words: angiotensin-(1-7), angiotensin II, hypertension


It is well recognized that the renin-angiotensin system plays an important role in the overall control of water and salt homeostasis. The generation of angiotensin II (Ang II) from angiotensin I (Ang I) has long been considered the final product of this system. Ang II induces a variety of actions in the vasculature, brain, pituitary, adrenal and kidney to augment blood pressure. These actions include vasoconstriction, cellular hypertrophy, salt and water retention and stimulation of drinking. Indeed, the inhibition of the renin angiotensin system has been shown to be a powerful strategy to lower blood pressure in the clinical setting.

Recent studies have revived the possibility that angiotensin peptides other than Ang II may either contribute to or actually oppose the cardiovascular actions of Ang II, endowing this hormonal system with a greater flexibility than originally imagined. The characterization of angiotensin-(1-7) (Ang-(1-7)) as the first amino terminal angiotensin peptide product possessing biological actions provided a foundation for the pursuit of a new concept regarding the regulation of cardiovascular function by the renin-angiotensin system. The accumulating evidence suggests that Ang-(1-7) may serve to counterbalance the actions of Ang II (1). This review updates the progress that has been made in the development of this concept by examining the diverse actions of Ang-(1-7) and the receptors that mediate these actions.

Pathways of angiotensin-(17) formation and degradation

Illustrated in Figure 1 are the major bioactive components of the renin-angiotensin system. As shown, the enzymatic cascade diverges with the processing of Ang I to either Ang II via converting enzyme (ACE ) or to Ang-(1-7). Ang II is then N-terminally metabolized to the smaller bioactive fragments Ang-(2-8) and Ang-(3-8) by peptidyl (AP) or dipeptidyl (DAP) aminopeptidases. Conversely, Ang I can be directly converted to Ang-(1-7) bypassing formation of Ang II (2). This pathway is potentially under the control of three endopeptidases which form Ang-(1-7) including neprilysin (NEP), thimet oligopeptidase (TO) and prolyl oligopeptidase (PO) (2), as well as ACE. Although the generation of Ang-(1-7) from Ang II has not been fully investigated, PO and prolyl carboxypeptidase (PCP) both cleave the Pro7-Phe8 bond of Ang II.

The biosynthetic pathways for the formation of Ang-(1-7) from Ang I are well understood; however, the route for the degradation of the peptide has not been elucidated. Several mechanisms have been postulated for the removal of peptides from the circulation including receptor-mediated processes (3,4) and enzymatic metabolism. We and others have recently shown that Ang-(1-7) is hydrolyzed to Ang-(1-5) by ACE in vitro (5,6). Initial evidence that Ang-(1-7) was a substrate for ACE arose from a comparison of the potencies of various angiotensin and bradykinin peptides to inhibit ACE activity. Ang-(1-7) was a more potent competitor of ACE than bradykinin, Ang I or substance P (Figure 2, top panel) (5,7). Interestingly, the Ang-(1-7) antagonist D-[Ala7]-Ang-(1-7) in which the carboxyl-terminal or C proline is substituted with D-alanine did not compete for activity (Figure 2) nor was the peptide hydrolyzed by ACE (Chappell MC, unpublished results). The complete inhibition with di-nitrofluorobenzene (DNFB, Figure 2, middle panel) and the greater potency of lisinopril over captopril (2.1 nM vs 27 nM, respectively; Figure 2, bottom panel) suggest that the C domain of ACE is primarily involved in the hydrolysis of Ang-(1-7) (8,9). However, Deddish et al. (6) have recently reported that Ang-(1-7) is a selective substrate for the amino or N domain of human ACE and may inhibit the C domain. Although both canine and human ACE exhibited similar kinetic values for Ang-(1-7), there may exist species differences concerning which domain participates in the hydrolysis of the peptide. The favorable kinetic constants (Km = 0.8 µM, kcat = 1.8/s for canine ACE) suggest an in vivo role for ACE in the regulation of Ang-(1-7) and recent studies demonstrate that lisinopril augments the half-life of infused Ang-(1-7) by 4- to 5-fold (10). Thus, the marked increase in circulating levels of Ang-(1-7) following chronic ACE inhibition reflects both increased synthesis (due to higher Ang I levels) and decreased metabolism.

Figure 1 - Pathways for the generation and metabolism of angiotensin peptides. Angiotensin I (Ang I) is processed to biologically active products through distinct enzymatic pathways. Ang II is formed by the hydrolysis of the Phe8-His9 bond of Ang I by angiotensin converting enzyme (ACE). Ang II is further processed by aminopeptidases (AP) or dipeptidyl aminopeptidases (DAP) to yield the active metabolites Ang-(2-8) and Ang-(3-8). Ang-(1-7) is formed by the hydrolysis at Pro7-Phe8 of Ang I by several endopeptidases including neprilysin (NEP), thimet oligopeptidase (TO) and prolyl oligopeptidase (PO) and from Ang II by PO and prolyl carboxypeptidase (PCP). Ang-(1-7) is hydrolyzed at the Ile5-His6 bond by ACE to yield Ang-(1-5); Ang II is cleaved at Tyr4-Ile5 by NEP to yield Ang-(1-4).

[View larger version of this image (24 K GIF file)]

Figure 2 - Top panel, Comparison of the potencies of angiotensin and bradykinin peptides to compete for ACE activity determined with the synthetic substrate Hip-His-Leu as described (5). Sub P, Substance P; Ang, angiotensin; BK, bradykinin; [D-Ala], D-[Ala7]-Ang-(1-7). Middle panel, Effects of di-nitrofluorobenzene (DNFB) on the ACE-dependent hydrolysis of Ang-(1-7) and Hip-His-Leu. Lower panel, Potencies of the inhibitors lisinopril, enalaprilat and captopril to inhibit the hydrolysis of Ang-(1-7) by ACE.

[View larger version of this image (22 K GIF file)]

Physiological actions of angiotensin-(1-7)

There is substantial evidence available now to demonstrate that the fragments formed from Ang I and Ang II metabolism are biologically active. Of the biologically active fragments studied to-date, the physiological actions of Ang-(1-7) have been most widely investigated. This peptide has been shown to be present in the plasma and a variety of tissues in both humans and rats. Ang-(1-7) elicits physiological effects that are similar or opposite to that of Ang II. In the brain, Ang-(1-7) stimulates release of vasopressin (11,12) and facilitates baroreflexes (13-15). However, unlike Ang II, the peptide does not stimulate dipsogenesis (16) or elicit potent vasoconstrictor actions. At the cellular level, Ang-(1-7) stimulates release of PGE2 and PGI2 (17-21), potentiates the hypotensive effects of bradykinin (7,22-25), and stimulates the release of nitric oxide (7,24,26). Finally Ang-(1-7) exerts a vasodilatory effect which may account for its antihypertensive effects that are manifested in vivo (19,27,28). The fact that the physiological effects of Ang-(1-7) are either identical or opposite to those of Ang II indicates that this is a pleiotropic fragment. Collectively, the various physiological effects of Ang-(1-7) mentioned above would favor a blood pressure lowering effect under conditions of high Ang II activity.

The biological function of the enzymes forming Ang-(1-7) reinforces the idea that this peptide is a component of a vasodepressor system regulating blood pressure. The two enzymes, neprilysin and thimet oligopeptidase that have been shown to form Ang-(1-7) from Ang I (2,29) also cleave bradykinin and the atrial natriuretic peptide to smaller fragments (30). These observations suggest that the various angiotensin products and other vasodepressor peptides are intertwined through these enzymatic pathways, and this is a concept of importance. Physiologists have always considered that Ang II could indirectly lead to activation of vasodepressor systems. However, the fact that Ang-(1-7) may exhibit antihypertensive actions and arises from Ang I points to its existence within the renin angiotensin system itself for mitigation of the actions of Ang II. Thus, the role of the smaller fragments of the renin angiotensin system in physiology and pathology should not be examined independently from Ang II.

The relationship between the status of the renin angiotensin system and the antihypertensive response to ACE inhibitors or Ang II antagonists is not a simple one. Often, these agents show good antihypertensive activity in the presence of normal or even suppressed renin activity (31,32). The argument has been posed that the chronic antihypertensive action of ACE inhibitors may be mediated by accumulation of tissue bradykinin (33). However, Cachofeiro et al. (34) reported that, in contrast to acute lisinopril treatment, the kinin B2 antagonist HOE 140 did not reverse the antihypertensive effects of chronic lisinopril treatment. We and others have reported similar observations in spontaneously hypertensive rats (SHR) treated with lisinopril/losartan and in renal hypertensive rats with ramipril treatment (35,36).

In this regard, we began a series of studies to determine whether Ang-(1-7) contributes to the antihypertensive effects of a combined lisinopril/losartan regimen in SHR. As shown in Figure 3, three strategies were employed to attenuate the potential actions of Ang-(1-7): 1) inhibition of Ang-(1-7) formation with a neprilysin inhibitor; 2) neutralization of the peptide by infusion of a selective monoclonal antibody (mAb-Ang-(1-7)), and 3) blockade of the receptor with the non-selective antagonist [Sar1,Thr8]-Ang II (Sarthran). The combined treatment with an ACE inhibitor and AT1 antagonist should favor the conversion of Ang I to Ang-(1-7) by neprilysin (37) and block actions at the AT1 receptor. Systemic administration of an Ang-(1-7) monoclonal antibody at increasing concentrations partially reversed the antihypertensive response in SHR chronically treated with lisinopril/losartan (Figure 4, top panel) (38). Acute inhibition of the endogenous synthesis of Ang-(1-7) by two different neprilysin inhibitors (SCH 39370 and CGS 24592) resulted in a similar reversal of the antihypertensive effect produced by the lisinopril/losartan in SHR (Figure 4, lower panel) (36). The increase in blood pressure with the neprilysin inhibitor CGS 24592 was associated with a 60% fall in the plasma concentrations of Ang-(1-7) (36). Administration of Sarthran also induced a pressor response in the SHR that was not attenuated by prior blockade with the AT2 antagonist PD 123319 and indicates that the vasodepressor actions of Ang-(1-7) are mediated via a non-AT1/AT2 receptor. In addition, prior treatment with Sarthran prevented any further increase in blood pressure with the CGS compound (Figure 4). These data suggest that the effects of ACE inhibitors may be partially mediated by Ang-(1-7) and add a new and important dimension to the understanding of the physiology of the renin angiotensin system.

Figure 3 - Strategy for the blockade of peripheral Ang-(1-7). Circulating angiotensin I (Ang I) is hydrolyzed to Ang-(1-7) by neprilysin (NEP) situated on the vascular surface. Attenuation of the vasodilator actions of Ang-(1-7) is achieved by either inhibiting the synthesis of the peptide with a neprilysin inhibitor (NEPI), neutralization of the circulating peptide with monoclonal antibody (mAb-Ang-(1-7)) or blockade of the putative receptor site with the non-selective antagonist [Sar1,Thr8]-Ang II (Sarthran).

[View larger version of this image (5 K GIF file)]

Figure 4 - Top panel, Peripheral administration of an Ang-(1-7) monoclonal antibody (Ab) increases mean arterial blood pressure (MAP) in chronically treated losartan/lisinopril spontaneously hypertensive rats (SHR) as described (38). Vehicle administration (Vehicle; normal mouse IgG, 400 µg/min) did not affect MAP. Bottom panel, Effect of neprilysin (NEP) inhibitors and angiotensin receptor antagonists on MAP from the losartan/lisinopril-treated SHR (36). Animals were acutely treated with the NEP inhibitors SCH 39370 (SCH), CGS 24592 (CGS) or the antagonists [Sar1,Thr8]-Ang II (SAR) or PD 123319 (PD).

[View larger version of this image (13 K GIF file)]

Receptors mediating the actions of ang-(1-7)

Accumulating evidence suggests that the effects of Ang-(1-7) are mediated by a unique angiotensin receptor (1,38). The stimulation of prostaglandin E2 and I2 synthesis, and nitric oxide release by Ang-(1-7) occur via activation of a receptor subtype distinct from AT1 and AT2 but recognized by the competitive non-selective Ang II antagonist Sarthran (1). Similarly, the in vivo vasodepressor effects of Ang-(1-7) have been shown to be mediated, in part, by non-AT1/AT2 receptor subtypes that are sensitive to Sarthran (38). In addition, a high affinity binding site has been described in bovine endothelial cells in culture (39) and canine coronary artery endothelium by in vitro autoradiography (1). Thus, the majority of the data available suggest that Ang-(1-7) may act at a novel non-AT1/AT2 receptor, the signal transduction pathway for which still remains to be elucidated. However, it should be noted that, under certain conditions, the effects of Ang-(1-7) may be blocked by losartan or to a variable extent by AT2 receptor antagonists (17,18,40), suggesting a heterogeneity of Ang-(1-7) receptors sensitive to either AT1 or AT2 antagonists. This may be particularly evident regarding the actions of Ang-(1-7) in the kidney (see below for further discussion of sites within the kidney).

Renal actions of angiotensin(1-7)

Renal infusion of Ang-(1-7) produced marked diuresis and natriuresis in the isolated (41) and intact kidney of Sprague Dawley (SD) and Wistar rats, respectively (42,43). In contrast to the potent renal actions of Ang II, Ang-(1-7) lacked any effect on renal blood flow and tended to increase the glomerular filtration rate (41,43). The diuretic actions of Ang-(1-7) in the isolated kidney were attenuated by the cyclooxygenase inhibitor indomethacin (44). In cultured renal tubular epithelial cells from rabbit, Ang-(1-7) inhibited transcellular sodium flux (45). Interestingly, the inhibition of sodium transport with Ang I was markedly potentiated by the ACE inhibitor captopril. The brush border of proximal tubules contains high concentrations of neprilysin, an endopeptidase which cleaves Ang I directly to Ang-(1-7) (46). Ang-(1-7) also inhibited transport-dependent oxygen consumption, a marker for Na-K-ATPase activity in isolated convoluted proximal tubules (43). This potent inhibition by Ang-(1-7) was partially blocked by an AT1 antagonist and completely attenuated by Sarthran while the AT2 antagonist PD 123319 had no effect. However, Ang-(1-7) exhibited biphasic effects on water and bicarbonate transport in perfused straight proximal tubules (47). A low concentration (1 pM) of Ang-(1-7) stimulated water transport, while 10 nM inhibited fluid absorption most probably by altering the Na+/H+ exchanger. The biphasic actions of Ang-(1-7) were completely blocked by losartan and the AT2 antagonist had no effect (47).

The effect of various angiotensin antagonists and the tubular actions of Ang-(1-7) suggest that this peptide may distinguish multiple AT1 receptor sites in the kidney. Santos and colleagues also report that Ang-(1-7) may interact with a novel AT1 or losartan-sensitive site in the kidney (12). Ang-(1-7) promotes an anti-diuretic action in water-loaded Wistar rats with a tendency for increased plasma vasopressin (12,48). Both the AT1 agent losartan and the Ang-(1-7) antagonist D-[Ala7]-Ang-(1-7) attenuated the anti-diuretic effects of Ang-(1-7) (49). The D-[Ala7] antagonist has also been reported to block the inhibition of water transport by Ang-(1-7) in a collecting duct preparation (12). The D-[Ala7]-Ang-(1-7) compound does not inhibit Ang II binding at typical AT1 or AT2 sites in the adrenal or attenuate the vasoconstrictor effects of Ang II (50).

The intriguing actions of Ang-(1-7) to inhibit diuresis are completely opposed to the effects observed in the perfused kidney and deserve further comment. One obvious difference in the studies with intact animals was that the experiments were performed after water loading. In human patients, differential effects were observed with AT1 treatment following an acute water load (51). Importantly, these data emphasize that the overall state of sodium and water balance, as well as the overall activity of the renin-angiotensin system may greatly influence the effects of Ang-(1-7) in the kidney. Perhaps of equal importance, the dose of the peptide, the route of administration and the site of the nephron exposed to Ang-(1-7) may also influence the actions of the peptide.


The angiotensin fragments of the renin angiotensin system cascade have been shown to possess biological activity although their role in the maintenance of the physiological process is still not clear. Of all these metabolites, Ang-(1-7) may be the most pleiotropic as it exerts effects that either oppose those of Ang II or comprise a subset of Ang II actions. The studies reported above provide a new understanding to the contribution of the renin angiotensin system in physiology and pathology.


1. Ferrario CM, Chappell MC, Tallant EA, Brosnihan KB & Diz DI (1997). Counter-regulatory actions of angiotensin-(1-7). Hypertension, 30: 535-541.         [ Links ]

2. Welches WR, Brosnihan KB & Ferrario CM (1993). A comparison of the properties, and enzymatic activity of three angiotensin processing enzymes: angiotensin converting enzyme, prolyl endopeptidase and neutral endopeptidase 24.11. Life Sciences, 52: 1461-1480.         [ Links ]

3. Iyer SN, Chappell MC, Brosnihan KB & Ferrario CM (1998). Role of AT1 and AT2 receptors in the plasma clearance of angiotensin II. Journal of Cardiovascular Pharmacology (in press).         [ Links ]

4. Vernace MA, Mento PF, Maita ME & Wilkes BM (1994). Effects of angiotensin receptor subtype inhibitors on plasma angiotensin clearance. Hypertension, 23: 853-856.         [ Links ]

5. Chappell MC, Pirro NT, Sykes A & Ferrario CM (1998). Metabolism of angiotensin-(1-7) by angiotensin converting enzyme. Hypertension, 31: 362-367.         [ Links ]

6. Deddish PA, Jackman HL, Wang H-Z, Skidgel RA & Erdos EG (1997). An N-domain specific substrate and C-domain specific inhibitor of angiotensin converting enzyme: Angiotensin1-7 and Keto-ACE. Hypertension, 30: 494 (Abstract).         [ Links ]

7. Li P, Chappell MC, Ferrario CM & Brosnihan KB (1997). Angiotensin-(1-7) augments bradykinin-induced vasodilation by competing with ACE and releasing nitric oxide. Hypertension, 29: 394-400.         [ Links ]

8. Wei L, Caluser E, Alhenc-Gelas F & Corvol P (1992). The two homologous domains of human angiotensin I-converting enzyme interact differently with competitive inhibitors. Journal of Biological Chemistry, 267: 13398-13405.         [ Links ]

9. Deddish PA, Wang LX, Jackman HL, Michel B, Wang J, Skidgel RA & Erdos EG (1996). Single-angiotensin I-converting enzyme (kininase II): characterization and properties. Journal of Pharmacology and Experimental Therapeutics, 279: 1582-1589.         [ Links ]

10. Yamada K, Iyer SN, Chappell MC, Ganten D & Ferrario CM (1998). Converting enzyme determines the plasma clearance of angiotensin-(1-7). Hypertension (in press).         [ Links ]

11. Schiavone MT, Santos RAS, Brosnihan KB, Khosla MC & Ferrario CM (1988). Release of vasopressin from the rat hypothalamo-neurohypophysial system by angiotensin-(1-7) heptapeptide. Proceedings of the National Academy of Sciences, USA, 85: 4095-4098.         [ Links ]

12. Santos RAS, Silva ACS, Magaldi AJ, Khosla MC, Ceasr KR, Passaglio KT & Baracho NCV (1996). Evidence for a physiological role of angiotensin-(1-7) in the control of hydroelectrolyte balance. Hypertension, 27: 875-884.         [ Links ]

13. Campagnole-Santos MJ, Heringer SB, Batista EN, Khosla MC & Santos RAS (1992). Differential baroreceptor reflex modulation by centrally infused angiotensin peptides. American Journal of Physiology, 263: R89-R94.         [ Links ]

14. Silva LCS, Fontes MAP, Campagnole-Santos MJ, Khosla MC, Campos Jr RR, Guertzenstein PG & Santos RAS (1993). Cardiovascular effects produced by micro-injection of angiotensin-(1-7) on vasopressor and vasodepressor sites of the ventrolateral medulla. Brain Research, 613: 321-325.         [ Links ]

15. Campagnole-Santos MJ, Diz DI, Santos RAS, Khosla MC, Brosnihan KB & Ferrario CM (1989). Cardiovascular effects of angiotensin-(1-7) injected into the dorsal medulla of rats. American Journal of Physiology, 257: H324-H329.         [ Links ]

16. Mahon JM, Allen M, Herbert J & Fitzsimons JT (1995). The association of thirst, sodium appetite and vasopressin release with c-fos expression in the forebrain of the rat after intracerebroventricular injection of angiotensin II, angiotensin-(1-7) or carbachol. Neuroscience Letters, 69: 199-208.         [ Links ]

17. Jaiswal N, Diz DI, Chappell MC, Khosla MC & Ferrario CM (1992). Stimulation of endothelial cell prostaglandin production by angiotensin peptides. Hypertension, 19 (Suppl II): 49-55.         [ Links ]

18. Jaiswal N, Tallant EA, Jaiswal RK, Diz DI & Ferrario CM (1993). Differential regulation of prostaglandin synthesis by angiotensin peptides in porcine aortic smooth muscle cells: Subtypes of angiotensin receptors involved. Journal of Pharmacology and Experimental Therapeutics, 265: 664-673.         [ Links ]

19. Benter IF, Ferrario CM, Morris M & Diz DI (1995). Antihypertensive actions of angiotensin-(I-7) in spontaneously hypertensive rats. American Journal of Physiology, 269: H313-H319.         [ Links ]

20. Jaiswal N, Jaiswal RK, Tallant EA, Diz DI & Ferrario CM (1993). Alterations in prostaglandin production in spontaneously hypertensive rat smooth muscle cells. Hypertension, 21: 900-905.         [ Links ]

21. Trachte GJ, Ferrario CM & Khosla MC (1990). Selective blockade of angiotensin responses in the rabbit isolated vas deferens by angiotensin receptor antagonists. Journal of Pharmacology and Experimental Therapeutics, 255: 929-934.         [ Links ]

22. Lima CV, Paula RD, Resende FL, Khosla MC & Santos RAS (1997). Potentiation of the hypotensive effect of bradykinin by short-term infusion of angiotensin-(1-7) in normotensive and hypertensive rats. Hypertension, 30: 542-548.         [ Links ]

23. Paula RD, Lima CV, Khosla MC & Santos RAS (1995). Angiotensin-(1-7) potentiates the hypotensive effect of bradykinin in conscious rats. Hypertension, 26: 1154-1159.         [ Links ]

24. Abbas A, Gorelik G, Carbini LA & Scicli AG (1997). Angiotensin-(1-7) induces bradykinin-mediated hypotensive responses in anesthetized rats. Hypertension, 30: 217-221.         [ Links ]

25. Porsti I, Bara AT, Busse R & Hecker M (1994). Release of nitric oxide by angiotensin-(1-7) from porcine coronary endothelium: implications for a novel angiotensin receptor. British Journal of Pharmacology, 111: 652-654.         [ Links ]

26. Osei SY, Ahima RS, Minkes RK, Weaver JP, Khosla MC & Kadowitz PJ (1993). Differential responses to angiotensin-(1-7) in the feline mesenteric and hindquarters vascular beds. European Journal of Pharmacology, 234: 35-42.         [ Links ]

27. Benter IF, Diz DI & Ferrario CM (1993). Cardiovascular actions of angiotensin-(1-7). Peptides, 14: 679-684.         [ Links ]

28. Benter IF, Diz DI & Ferrario CM (1995). a-Adrenergic and angiotensin II pressor responses are reduced in angiotensin-(1-7)-treated spontaneously hypertensive rats. Hypertension, 25: 1416 (Abstract).         [ Links ]

29. Chappell MC, Tallant EA, Brosnihan KB & Ferrario CM (1994). Conversion of angiotensin I to angiotensin-(1-7) by thimet oligopeptidase (EC in vascular smooth muscle cells. Journal of Vascular Medicine and Biology, 5: 129-137.         [ Links ]

30. Erdos EG (1990). Angiotensin I converting enzyme and the changes in our concepts through the years. Hypertension, 16: 363-370.         [ Links ]

31. Biollaz J, Brunner HR, Gavras I, Waeber B & Gavras H (1982). Antihypertensive therapy with MK 421: angiotensin II-renin relationships to evaluate efficacy of converting enzyme blockade. Journal of Cardiovascular Pharmacology, 4: 966-972.         [ Links ]

32. Brunner HR, Gavras H, Turini GA, Waeber B, Chappuis P & McKinstry DN (1978). Long term treatment of hypertension in man by an orally active angiotensin-converting enzyme inhibitor. Clinical Science and Molecular Medicine, 55: 2934-2959.         [ Links ]

33. Carretero OA, Miyazaki S & Scicli AG (1981). Role of kinins in the acute antihypertensive activity of the converting enzyme inhibitor, captopril. Hypertension, 3: 18-22.         [ Links ]

34. Cachofeiro V, Maeso R, Rodrigo E, Navarro J, Ruilope LM & Lahera V (1995). Nitric oxide and prostaglandins in the prolonged effects of losartan and ramipril in hypertension. Hypertension, 26: 236-243.         [ Links ]

35. Bao G, Gohlke P & Unger T (1992). Role of bradykinin in chronic antihypertensive actions of ramipril in different hypertension models. Journal of Cardiovascular Pharmacology, 20: S96-S99.         [ Links ]

36. Iyer SN, Ferrario CM & Chappell MC (1998). Angiotensin-(1-7) contributes to the antihypertensive effects of blockade of the renin-angiotensin system. Hypertension, 31: 356-361.         [ Links ]

37. Yamamoto K, Chappell MC, Brosnihan KB & Ferrario CM (1992). In vivo metabolism of angiotensin I by neutral endopeptidase (EC in spontaneously hypertensive rats. Hypertension, 19: 692-696.         [ Links ]

38. Iyer SN, Chappell MC, Averill DB, Diz DI & Ferrario CM (1998). Vasodepressor actions of angiotensin-(1-7) unmasked during combined treatment with lisinopril and losartan. Hypertension, 31: 699-705.         [ Links ]

39. Tallant EA, Lu X, Weiss RB, Chappell MC & Ferrario CM (1997). Bovine aortic endothelial cells contain an angiotensin-(1-7) receptor. Hypertension, 29: 388-392.         [ Links ]

40. Tallant EA, Diz DI, Khosla MC & Ferrario CM (1991). Identification and regulation of angiotensin II receptor subtypes on NG108-15 cells. Hypertension, 17: 1135-1143.         [ Links ]

41. DelliPizzi A, Hilchey SD & Bell-Quilley CP (1994). Natriuretic actions of angiotensin-(1-7). British Journal of Pharmacology, 111: 1-3.         [ Links ]

42. Heyne N, Beer W, Muhlbauer B & Osswald H (1995). Renal response to angiotensin (1-7) in anesthetized rats. Kidney International, 47: 975-976 (Abstract).         [ Links ]

43. Handa RK, Ferrario CM & Strandhoy JW (1996). Renal actions of angiotensin-(1-7) in vivo and in vitro studies. American Journal of Physiology, 270: F141-F147.         [ Links ]

44. Hilchey SD & Bell-Quilley CP (1995). Association between the natriuretic action of angiotensin-(1-7) and selective stimulation of renal prostaglandin I2 release. Hypertension, 25: 1238-1244.         [ Links ]

45. Andreatta-Van Leyen S, Romero MF, Khosla MC & Douglas JG (1993). Modulation of phospholipase A2 activity and sodium transport by angiotensin-(1-7). Kidney International, 44: 932-936.         [ Links ]

46. Stephenson SL & Kenny AJ (1987). Metabolism of neuropeptides. Biochemistry Journal, 241: 237-247.         [ Links ]

47. Garcia NH & Garvin JL (1994). Angiotensin 1-7 has a biphasic effect on fluid absorption in the proximal straight tubule. Journal of the American Society of Nephrology, 5: 1133-1138.         [ Links ]

48. Santos RAS & Baracho NCV (1992). Angiotensin-(1-7) is a potent anti-diuretic peptide in rats. Brazilian Journal of Medical and Biological Research, 25: 651-654.         [ Links ]

49. Baracho NCV, Silva ACE, Khosla MC & Santos RAS (1995). Characterization of the anti-diuretic action of angiotensin-(1-7) in water-loaded rats. Hypertension, 25: 1408 (Abstract).         [ Links ]

50. Santos RAS, Campagnole-Santos MJ, Baracho NCV, Fontes MAP, Silva LCS, Neves LAA, Oliveira DR, Caligiorne SM, Rodrigues ARV, Gropen Jr C, Carvalho WS, Silva ACSE & Khosla MC (1994). Characterization of a new angiotensin antagonist selective for angiotensin-(1-7): evidence that the actions of angiotensin-(1-7) are mediated by specific angiotensin receptors. Brain Research Bulletin, 35: 293-398.         [ Links ]

51. Burnier M, Pechere-Bertschi A, Nussberger J, Waeber B & Brunner HR (1995). Studies of the renal effects of angiotensin II receptor blockade: the confounding factor of acute water loading on the action of vasoactive systems. American Journal of Kidney Diseases, 26: 108-115.         [ Links ]


We thank Drs. A.J. Trapani (Novartis Corporation, Summit, NJ) and E.J. Sybertz (Schering-Plough Corp., Kenilworth, NJ) for their generous gifts of CGS 24592 and SCH 39370, respectively.

Correspondence and Footnotes

Address for correspondence: M.C. Chappell, The Hypertension and Vascular Disease Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1032, USA. Fax: (336) 716-0269. E-mail:

Presented at the II International Symposium on Vasoactive Peptides, Ouro Preto, MG, Brasil, October 6-8, 1997. Research supported in part by RO1 (Nos. HL38535, HL56973, HL50066, P01-HL51952 and T35-HL0779). Received February 18, 1998. Accepted March 16, 1998.

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License