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1 Institut für Physiologie und Pathophysiologie, Ruprecht-Karls Universität, 69120 Heidelberg; 3 Zentrum für Physiologie und Pathophysiologie, Universität Köln, 50931 Köln; and 2 Institut für Physiologie, Universität Hamburg, 20246 Hamburg, Germany
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ABSTRACT |
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Locally released endothelin (ET)-1 has been recently identified as an important mediator of cardiac hypertrophy. It is still unclear, however, which primary stimulus specifically activates ET-dependent signaling pathways. We therefore examined in adult rats (n = 51) the effects of a selective ETA receptor antagonist in experimental models of cardiac hypertrophy, in which myocardial growth is predominantly initiated by a single primary stimulus. Rats were exposed to mechanical overload (ascending aortic stenosis), increased levels of circulating ANG II (ANG II infusion combined with hydralazine), or adrenergic stimulation (infusion of norepinephrine in a subpressor dose) for 7 days. All experimental treatments significantly increased left ventricular weight/body weight ratios compared with untreated rats, whereas systolic left ventricular peak pressure was increased only after ascending aortic stenosis. ETA receptor blockade exclusively reduced norepinephrine-induced cardiac hypertrophy and atrial natriuretic peptide gene expression. Blood pressure levels and heart rates remained unaffected during ETA receptor blockade in all experimental groups. These data indicate that in rat left ventricle, the ET-dependent signaling pathway leading to early development of cardiac hypertrophy and fetal gene expression is primarily activated by norepinephrine.
angiotensin II; endothelin-A receptor; gene expression; norepinephrine; remodeling
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INTRODUCTION |
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ENDOTHELIN (ET) is a potent vasoconstrictor that was first described by Yanagisawa and co-workers in 1988 (35). During the past years, it has become clear that in addition to its hemodynamic effects, ET-1 can also act as a growth-promoting hormone in the myocardium. Initial observations made on isolated cardiomyocytes revealed an increase of protein biosynthesis and cellular volume after the addition of ET-1 to the culture medium (11). Consecutive studies in intact animals demonstrated a stimulation of the cardiac ET system in several forms of extrinsic cardiac hypertrophy (2, 10, 12, 15, 20, 21), particularly during its early development (12, 15, 21). Correspondingly, either selective ETA subtype receptor blockade or unselective ETA/B subtype receptor blockade significantly attenuated early myocardial hypertrophy and fetal gene expression associated with renal artery stenosis (7, 9), suprarenal abdominal aortic banding (12), ANG II infusion (8), and high-dose infusion of norepinephrine (NE) (15). In all of these pathophysiologically relevant models, however, several primary stimuli, which can individually induce myocardial hypertrophy, are activated concurrently, i.e., mechanical load, the renin-angiotensin system, and/or the sympathetic nervous system. Accordingly, it remains unclear whether the cardiac ET system is specifically activated either by one or by a combined action of several primary stimuli or whether it constitutes a more general downstream signaling pathway of myocardial growth.
In the present study, we therefore sought to design experimental
paradigms of extrinsically induced cardiac hypertrophy, in which
myocardial growth is predominantly initiated by a single primary
stimulus. To increase mechanical load to the ventricle, in one group of
animals the ascending aorta was banded directly at the root of the
aortic arch. In a previous study, we found that this procedure does not
stimulate the circulating renin-angiotensin system (33).
The observation by others that myocardial growth after ascending aortic
stenosis is neither diminished by angiotensin AT1 receptor
blockade (32) nor by angiotensin-converting enzyme inhibition (37) strongly suggests that the local cardiac
renin-angiotensin system does not participate in the growth response to
mechanical overload. To investigate the isolated role of circulating
ANG II in ET-dependent cardiac hypertrophy, in a second group of rats ANG II was chronically infused subcutaneously via osmotic minipumps. These animals also received the vasodilator hydralazine to prevent increases in blood pressure induced by the elevation of circulating ANG
II levels. This experimental protocol has previously been shown to
induce blood pressure-independent myocardial growth (17). There is at present no evidence indicating any significant contribution of an increased sympathetic activity in these two experimental forms of
cardiac hypertrophy. Finally, to initiate cardiac hypertrophy primarily
via a stimulation of myocardial
1/
1-adrenoceptors (36), a
third group of animals received chronic infusions of NE at a low dose
(100 µg · kg body
wt
1 · h
1). To assess the
participation of the ET system in each of these experimental forms of
extrinsic cardiac hypertrophy, animals were treated with either saline
or the ETA receptor antagonist LU-135252 (27).
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METHODS |
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Experimental groups.
Experiments were conducted on a total of 51 female Sprague-Dawley rats
weighing 180-200 g (9 wk old). All surgical procedures were performed under anesthesia with ketamine/xylazine (4 and 100 mg/kg
body wt, respectively). Constriction of the ascending aorta was
performed as described previously. ANG II was chronically administered
at a rate of 200 ng · kg body
wt
1 · min
1 via osmotic minipumps
(Alzet model 2001, Charles River) that were implanted
subcutaneously. In female rats, this dose of ANG II induces a
moderate increase in mean arterial blood pressure and significant left
ventricular hypertrophy by ~10-15% after 7 days of chronic
infusion (34; compare Ref. 17). To prevent changes in
blood pressure, hydralazine was given with the drinking water to ANG
II-infused rats. The daily intake was 10 mg/kg body wt as calculated
from the average consumption of water. NE was chronically administered
via osmotic minipumps at a rate of 100 µg · kg body
wt
1 · h
1. Preliminary experiments
in our laboratory showed that this dose induces left ventricular
hypertrophy without affecting systolic or mean arterial blood pressure.
All animals survived the experimental interventions and were included
in the final analysis.
1 · day
1
with the diet resulted in morning plasma levels of LU-135252 of ~30
µmol/l (2). In dogs, oral administration of LU-135252 at
doses of 10 and 30 mg/kg body wt completely blocked the pressor effect
of intravenous bolus injections of 0.75 nmol/kg ET-1 (24). Accordingly, the administration of 25 mg/kg body wt of LU-135252 twice
daily (i.e., every 12 h) by gavage should provide a high degree
(>99%) of ETA receptor blockade.
At the end of the experimental period of 7 days, animals were
anesthetized and left ventricular peak pressure or systolic aortic
blood pressure was measured by directly puncturing the chamber from the
abdominal cavity through the diaphragm or via a catheter inserted into
the left A. femoralis and advanced into the abdominal aorta. Heart
rates were derived from the direct pressure signal. After completion of
the hemodynamic measurements, animals were killed and ratios of left
ventricular weight to body weight were determined as an estimate of
left ventricular hypertrophy. Then left ventricular tissue was frozen
with liquid nitrogen and stored at
80°C for determination of levels
of atrial natriuretic peptide (ANP) mRNA. All experiments were
conducted in accordance with institutional guidelines and the
Guide for the Care and Use of Laboratory Animals put forth
by the U.S. Department of Health and Human Services, National
Institutes of Health Publication No. 86-23, and were approved by
local authorities.
RNA analysis. RNA was extracted from ventricles pulverized under liquid nitrogen (5). It was confirmed that the probes used for mRNA analysis hybridized to a single band of the appropriate molecular weight by Northern blot analysis (33). For quantification, RNA was blotted to nitrocellulose in serial dilutions (4, 2, and 1 µg RNA/slot) using a vacuum filtration slot blot apparatus. Blots were probed consecutively with cDNA probes specific for ANP mRNA (plasmid containing a 145-bp, PCR-derived sequence of rat preproANP mRNA was kindly donated by Prof. Forssmann, Hannover, Germany) and 28S rRNA under conditions described in detail previously (7). Autoradiographs of the slot blots were scanned densitometrically, and tissue levels of ANP mRNA were expressed as arbitrary densitometric units/28S densitometric units taking care that the signal was in the linear range for all measurements.
Statistical analysis. Statistical analysis was performed using Graph-pad prism software. For a statistical evaluation of the effects of the different treatments compared with sham-treated animals, blood pressure data and ratios of left ventricular weight to body weight were analyzed by one-way ANOVA followed by the Bonferroni test. Statistical analysis of the effects of ETA receptor antagonism was made separately for each group by the two-tailed, unpaired Student's t-test. All data are expressed as means ± SE. A value of P < 0.05 was considered significant.
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RESULTS |
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The effects of the different experimental interventions to induce
cardiac hypertrophy are summarized in Table
1. Banding of the ascending aorta
significantly increased left ventricular peak pressure from 115 ± 5 to 182 ± 7 mmHg (P < 0.001; n = 8). On the contrary, blood pressure was neither elevated by chronic infusion of ANG II combined with hydralazine nor by chronic low-dose infusion of NE. All three experimental treatments caused significant left ventricular hypertrophy, as indicated by increased ratios of left
ventricular weight to body weight. None of the interventions caused a
decrease in body weight (data not shown). Left ventricular hypertrophy
was most pronounced in the ascending aortic banding group (39 vs. 18%
in the ANG II-infused group and 24% in the NE-infused group). ANP gene
expression was elevated in all groups. Interestingly, ANP-to-28S ratios
were considerably higher after aortic banding and chronic NE infusion
than after ANG II combined with hydralazine (where the difference
failed to reach statistical significance), indicating that different
primary hypertrophic stimuli induce different cardiac gene expression
patterns.
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The effects of ETA receptor blockade on the increase
in left ventricular mass and ANP gene expression induced by the
different experimental interventions are depicted in Figs.
1-3.
ETA receptor blockade had no effects on body weight in any
of the experimental groups (data not shown). In ascending aortic-banded
animals, ETA receptor blockade had no effects on the
development of left ventricular hypertrophy or myocardial expression of
the ANP gene compared with animals treated with saline (Fig. 1).
Similarly, left ventricular hypertrophy and ANP gene expression
remained unaffected by ETA receptor blockade in animals
subjected to ANG II combined with hydralazine (Fig. 2). In contrast,
both increase in left ventricular mass as well as stimulation of left
ventricular ANP gene expression were significantly reduced by >50% in
rats with NE-induced cardiac hypertrophy (Fig. 3). In all three
treatment groups, chronic ETA receptor blockade by
LU-135252 remained without effects on blood pressure and heart rate
(Figs. 1-3).
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DISCUSSION |
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The present results demonstrate that neither an increase in mechanical load nor elevated levels of ANG II without concurrent changes in blood pressure induces cardiac hypertrophy or ANP gene expression via the ETA receptor-signaling pathway within 7 days after induction. In contrast, blockade of ETA receptors significantly attenuated NE-induced cardiac growth and ANP gene expression. These data suggest that the myocardial ET signaling pathway mediating early cardiac hypertrophy and ANP gene expression is primarily activated by NE.
The finding that cardiac hypertrophy caused by an increase in mechanical load was unaffected by ETA receptor blockade seems to be at variance with an earlier study by Ito et al. (12) who observed a significant reduction of cardiac remodeling by the selective ETA receptor blocker BQ-123. In contrast to the present study, these investigators used suprarenal abdominal aortic banding, which resembles the experimental model of one-kidney, one-clip hypertension, to induce an elevation of blood pressure. In dogs, suprarenal abdominal aortic banding has been shown to activate the renin-angiotensin system, whereas plasma renin activity (PRA) did not change after ascending aortic banding because of an elevated cardiac filling pressure causing an increased release of ANP and a stimulation of cardiac mechanoreceptors (18). In a previous study, we could also show that in rats subjected to ascending aortic stenosis, PRA remains unchanged (33). Because PRA was not determined by Ito et al. (12), it remains unclear whether suprarenal abdominal aortic banding directly increased left ventricular peak pressure similar to ascending aortic banding or whether the hypertension was secondary to an activation of the renin-angiotensin system and/or fluid retention. The rather slow increase in blood pressure (>24 h) after abdominal banding reported by Ito et al. (12), however, speaks in favor of the latter alternative.
Most unexpectedly, ETA receptor blockade also had no effects on cardiac hypertrophy and ANP gene expression induced by ANG II. Several recent studies strongly implicated a close interplay between ANG II and ET in the regulation of cardiac growth. In cultured neonatal cardiomyocytes, ANG II upregulated ET gene expression and ET-1 release at a dose that induced cellular hypertrophic growth (11). The increase in protein synthesis induced by ANG II was completely blocked by either selective ETA receptor blockade, antisense oligonucleotides against preproET-1, or AT1 receptor blockade (11). These results suggested that locally released ET-1 may act as an important mediator of ANG II-induced myocardial growth. Further in vivo studies demonstrated that ET antagonism was very effective in blocking vascular remodeling (6, 8, 22) and enhanced vascular responsiveness (6, 26) in chronically ANG II-infused rats. In these studies, however, blood pressure increased considerably in response to ANG II, and ET antagonism significantly reduced this hypertension (6, 8, 22, 26). Similarly, cardiac hypertrophy associated with renovascular hypertension was largely blunted by administration of a selective ETA receptor antagonist, particulary during the early pressure-independent phase (7). Long-term ETA receptor blockade in rats with renovascular hypertension did not affect blood pressure or cardiac hypertrophy, but it completely prevented vascular remodeling of intramyocardial arteries (9). Again, it is important to note that renovascular hypertension does not represent a condition with a pure stimulation of the renin-angiotensin system, but it is associated with a marked increase of sympathetic activity and the release of NE in both experimental animal models (16) as well as humans (13). The present observations of a lack of effect of ETA receptor blockade on left ventricular hypertrophy and ANP gene expression induced by a "pure" elevation of circulating ANG II levels may therefore suggest that the inhibitory influences of ET antagonism found in these former studies may have been secondary to alterations in blood pressure and/or sympathetic activity.
A reduction of cardiac hypertrophy induced by chronic NE infusions was
also recently found after unselective ETA/B receptor blockade by bosentan (15). In contrast to the present
study, however, left ventricular ANP gene expression remained
unaffected. One possible explanation for this discrepancy may be
related to differences in ET antagonism (selective vs. nonselective
blockade). Alternatively, the much higher dose of 600 µg · kg
body wt
1 · h
1 of NE used by
Kaddoura and co-workers (15) may have elicited different
responses in myocardial gene expression. In preliminary experiments, we found that chronic infusion of NE at this rate was
lethal within 48 h after surgery in 80% of infused rats. In the
surviving animals, we observed a very pronounced increase in left
ventricular weight-to-body weight ratios and marked increases in blood
pressure by 40-50 mmHg. Unfortunately, blood pressures were not
reported by Kaddoura and co-workers (15). Also, in the
present investigation, blood pressures were only determined at a single
time point during anesthesia. Because cardiac unloading can cause a
rapid reduction of left ventricular mass even in the presence of
intense neurohumoral stimulation by ET-1 (19), further experiments in awake rats need to be performed to clarify this issue.
A limitation of the present study is that it does not differentiate between effects on cardiomyocytes, fibroblasts, and extracellular matrix. Accumulating evidence suggests that ET-dependent signaling may significantly affect cardiac fibrosis in various forms of cardiac hypertrophy (2, 9, 23). It seems very likely that the primary stimuli investigated here (mechanical load, ANG II, and NE) contribute to different extents to those different aspects of cardiac remodeling. Their individual precise effects on collagen deposition, increase in extracellular matrix, and activation of cardiac fibroblasts cannot be estimated from the present study. It should be noted, however, that the increase in interstitial volume observed in early stages of cardiac hypertrophy does not exceed ~1-2% of total volume (2, 9, 32). In the present study, left ventricular weight-to-body weight ratios increased by 18-39% (Table 1). This indicates that most of the increase in left ventricular mass in response to all three primary stimuli can be attributed to cardiomyocyte hypertrophy.
Perspectives
The present findings imply a major role for an interaction between the sympathetic nervous system (or circulating catecholamines) and the myocardial ET system during the early development of cardiac hypertrophy. This is particularly interesting from a pathogenic point of view, as several studies suggest that ET-1 may act as a "triggering factor" for myocardial growth (12, 15, 21). Isolated cardiac myocytes display a hypertrophic response with
-adrenergic stimulation (30, 31), and it has
recently been shown that the
1-adrenoreceptor agonist
phenylephrine induces ET-1 gene expression and accelerates the
conversion of big ET to bioactive ET-1 in cultured neonatal
cardiomyocytes (14). Stimulation of the cardiac ET system
with adrenergic activation therefore appears to constitute an important
signaling pathway of early myocardial growth, which may initiate
cardiomyocyte hypertrophy even in pathophysiological states without
obvious catecholamine excess such as renal artery stenosis
(7). The therapeutic value of ET antagonism for the
treatment of cardiac hypertrophy, however, remains to be clarified.
Although blocking the ET system has been shown to prevent excessive
myocardial hypertrophy in cardiac failure (29), it may
also be harmful under pathophysiological conditions such as myocardial
infarction, when early compensatory cardiac growth induced by
adrenergic stimulation is required.
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ACKNOWLEDGEMENTS |
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This work was supported by the Deutsche Forschungsgemeinschaft (SFB 320, C5 to R. Wiesner) and Knoll AG, Ludwigshafen, Germany (to H. Ehmke). J. Faulhaber received a scholarship from the Graduiertenkolleg "Experimentelle Nieren-und Kreislaufforschung."
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FOOTNOTES |
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* L. Moser and J. Faulhaber contributed equally to this work.
Address for reprint requests and other correspondence: H. Ehmke, Institut für Physiologie, Universität Hamburg, Martinistrase 52, D-20246 Hamburg, Germany (E-mail: ehmke{at}uke.uni-hamburg.de).
The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
First published January 24, 2002;10.1152/ajpregu.00685.2001
Received 16 November 2001; accepted in final form 16 January 2002.
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REFERENCES |
|---|
|
|
|---|
1.
Amann, K,
Miltenberger-Miltenyi G,
Simonoviciene A,
Koch A,
Orth S,
and
Ritz E.
Remodeling of resistance arteries in renal failure: effect of endothelin receptor bloackade.
J Am Soc Nephrol
12:
2040-2050,
2001.
2.
Amann, K,
Münter K,
Wessels S,
Wagner J,
Baljew V,
Hergenröder S,
Mall G,
and
Ritz E.
Endothelin A receptor blockade prevents capillary/myocyte mismatch in the heart of uremic animals.
J Am Soc Nephrol
11:
1702-1711,
2000.
3.
Barton, M,
d'Uscio LV,
Shaw S,
Meyer P,
Moreau P,
and
Lüscher TF.
ETA receptor blockade prevents increased tissue endothelin-1, vascular hypertrophy, and endothelial dysfunction in salt-sensitive hypertension.
Hypertension
31:
499-504,
1998.
4.
Bohlender, J,
Gerbaulet S,
Krämer J,
Gross M,
Kirchengast M,
and
Dietz R.
Synergistic effects of AT1 and ETA receptor blockade in a transgenic, angiotensin II-dependent rat model.
Hypertension
35:
992-997,
2000.
5.
Chomczynski, P,
and
Sacchi N.
Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.
Anal Biochem
162:
156-159,
1987.
6.
D'Uscio, LV,
Moreau P,
Shaw S,
Takase H,
Barton M,
and
Lüscher TF.
Effects of chronic ETA-receptor blockade in angiotensin II-induced hypertension.
Hypertension
29:
435-441,
1997.
7.
Ehmke, H,
Faulhaber J,
Münter K,
Kirchengast M,
and
Wiesner RJ.
Chronic ETA receptor blockade attenuates cardiac hypertrophy independently of blood pressure effects in renovascular hypertensive rats.
Hypertension
33:
954-960,
1999.
8.
Herizi, A,
Jover B,
Bouriquet N,
and
Mimran A.
Prevention of the cardiovascular and renal effects of angiotensin II by endothelin blockade.
Hypertension
31:
10-14,
1998.
9.
Hocher, B,
George I,
Rebstock J,
Bauch A,
Schwarz A,
Neumayer HH,
and
Bauer C.
Endothelin system-dependent cardiac remodeling in renovascular hypertension.
Hypertension
33:
816-822,
1999.
10.
Iemitsu, M,
Miyauchi T,
Maeda S,
Sakai S,
Kobayashi T,
Fujii N,
Miyazaki H,
Matsuda M,
and
Yamaguchi I.
Physiological and pathological cardiac hypertrophy induce different molecular phenotypes in the rat.
Am J Physiol Regulatory Integrative Comp Physiol
281:
R2029-R2036,
2001.
11.
Ito, H,
Hirata Y,
Adachi S,
Tanaka M,
Tsujino M,
Koike A,
Nogami A,
Marumo F,
and
Hiroe M.
Endothelin-1 is an autocrine/paracrine factor in the mechanism of angiotensin II-induced hypertrophy in cultured rat cardiomyocytes.
J Clin Invest
92:
398-403,
1993.
12.
Ito, H,
Hiroe M,
Hirata Y,
Fujisaki H,
Adachi S,
Akimoto H,
Ohta Y,
and
Marumo F.
Endothelin ETA receptor antagonist blocks cardiac hypertrophy provoked by hemodynamic overload.
Circulation
89:
2198-2203,
1994.
13.
Johansson, M,
Elam M,
Rundquist B,
Eisenhofer G,
Herlitz H,
Lambert G,
and
Friberg P.
Increased sympathetic nerve activity in renovascular hypertension.
Circulation
99:
2537-2542,
1999.
14.
Kaburagi, S,
Hasegawa K,
Morimoto T,
Araki M,
Sawamura T,
Masaki T,
and
Sasayama S.
Development of
1-adrenergic-stimulated hypertrophy in cultured neonatal rat cardiac myocytes.
Circulation
99:
292-298,
1999.
15.
Kaddoura, S,
Firth JD,
Boheler KR,
Sugden PH,
and
Poole-Wilson PA.
Endothelin-1 is involved in norepinephrine-induced ventricular hypertrophy in vivo.
Circulation
93:
2068-2079,
1996.
16.
Katholi, RE.
Renal nerves in the pathogenesis of hypertension in experimental animals and humans.
Am J Physiol Renal Fluid Electrolyte Physiol
245:
F1-F14,
1983.
17.
Kim, S,
Ohta K,
Hamaguchi A,
Yukimura T,
Miura K,
and
Iwao H.
Angiotensin II induces cardiac phenotypic modulation and remodeling in vivo in rats.
Hypertension
25:
1252-1259,
1995.
18.
Lee, ME,
Trasher TN,
and
Ramsay DJ.
Elevated cardiac pressure inhibits renin release after arterial hypotension in conscious dogs.
Am J Physiol Regulatory Integrative Comp Physiol
247:
R953-R959,
1984.
19.
Lisy, O,
Redfield MM,
Jovanovic S,
Jougasaki M,
Jovanovic A,
Leskinen H,
Terzic A,
and
Burnett JC.
Mechanical unloading versus neurohumoral stimulation on myocardial structure and endocrine function in vivo.
Circulation
102:
338-343,
2000.
20.
Luchner, A,
Jougasaki M,
Friedrich E,
Borgeson DD,
Stevens TL,
Redfield MM,
Riegger GAJ,
and
Burnett JC.
Activation of cardiorenal and pulmonary tissue endothelin-1 in experimental heart failure.
Am J Physiol Regulatory Integrative Comp Physiol
279:
R974-R979,
2000.
21.
Massart, PE,
Donckier J,
Kyselovic J,
Godfraind T,
Heyndrickx GR,
and
Wibo M.
Carvedilol and lacidipine prevent cardiac hypertrophy and endothelin-1 gene overexpression after aortic banding.
Hypertension
34:
1197-1201,
1999.
22.
Moreau, P,
d'Uscio LV,
Shaw S,
Takase H,
Barton M,
and
Lüscher TF.
Angiotensin II increases tissue endothelin and induces vascular hypertrophy. Reversal by ETA-receptor antagonist.
Circulation
96:
1593-1597,
1997.
23.
Mulder, P,
Boujedaini H,
Richard V,
Derumeaux G,
Henry JP,
Renet S,
Wessale J,
Opgenorth T,
and
Thuillez C.
Selective endothelin-A versus combined endothelin-A/endothelin-B receptor blockade in rat chronic heart failure.
Circulation
102:
491-493,
2000.
24.
Münter, K,
Ehmke H,
and
Kirchengast M.
Maintenance of blood pressure in normotensive dogs by endothelin.
Am J Physiol Heart Circ Physiol
276:
H1022-H1027,
1999.
25.
Münter, K,
Hergenröder S,
Unger L,
and
Kirchengast M.
Oral treatment with an ETA-receptor antagonist inhibits neointima formation induced by endothelial injury.
Pharm Pharmacol Lett
6:
90-92,
1996.
26.
Rajagopalan, S,
Laursen JB,
Borthayre A,
Kurz S,
Keiser J,
Haleen S,
Giaid A,
and
Harrison DG.
Role for endothelin-1 in angiotensin II-mediated hypertension.
Hypertension
30:
29-34,
1997.
27.
Riechers, H,
Albrecht HP,
Amberg W,
Baumann E,
Bernard H,
Böhm HJ,
Klinge D,
Kling A,
Müller S,
Raschack M,
Unger L,
Walker N,
and
Wernet W.
Discovery and optimization of a novel class of orally active nonpeptidic endothelin-A receptor antagonists.
J Med Chem
39:
2123-2128,
1996.
28.
Ruschitzka, F,
Quaschning T,
Noll G,
deGottardi A,
Rossier MF,
Enseleit F,
Hürlimann D,
Lüscher TF,
and
Shaw SG.
Endothelin 1 type A receptor antagonism prevents vascular dysfunction and hypertension induced by 11
-hydroxysteroid dehydrogenase inhibition: role of nitric oxide.
Circulation
103:
3129-3135,
2001.
29.
Sakai, S,
Miyauchi T,
Sakurai T,
Kasuya Y,
Ihara M,
Yamaguchi I,
Goto K,
and
Sugishita Y.
Endogenous endothelin-1 participates in the maintenance of cardiac function in rats with congestive heart failure.
Circulation
93:
1214-1222,
1996.
30.
Schlüter, KD,
Millar BC,
McDermott BJ,
and
Piper HM.
Regulation of protein synthesis and degradation in adult ventricular cardiomyocytes.
Am J Physiol Cell Physiol
269:
C1347-C1355,
1995.
31.
Simpson, P.
Norepinephrine-stimulated hypertrophy of cultured rat myocardial cells is an
1 adrenergic response.
J Clin Invest
72:
732-738,
1983.
32.
Weinberg, EO,
Lee MA,
Weigner M,
Lindpaintner K,
Bishop SP,
Benedict CR,
Ho KKL,
Douglas PS,
Chafizadeh E,
and
Lorell BH.
Angiotensin AT1 receptor inhibition; effects on hypertrophic remodeling and ACE expression in rats with pressure-overload hypertrophy due to ascending aortic stenosis.
Circulation
95:
1592-1600,
1997.
33.
Wiesner, RJ,
Ehmke H,
Faulhaber J,
Zak R,
and
Rüegg JC.
Dissociation of left ventricular hypertrophy,
-myosin heavy chain gene expression, and myosin isoform switch in rats after ascending aortic stenosis.
Circulation
95:
1253-1259,
1997.
34.
Wiesner, RJ,
Moser L,
and
Ehmke H.
Mechanical stretch and angiotensin II lead to cardiac hypertrophy via different mechanisms (Abstract).
FASEB J
12:
A977,
1998.
35.
Yanagisawa, M,
Kurihara H,
Kimura S,
Tomobe Y,
Kobayashi M,
Mitsui Y,
Yazaki Y,
Goto K,
and
Masaki T.
A novel potent vasoconstrictor peptide produced by vascular endothelial cells.
Nature
332:
411-415,
1988.
36.
Zierhut, W,
and
Zimmer HG.
Significance of myocardial
- and
-adrenoreceptors in catecholamine-induced cardiac hypertrophy.
Circ Res
65:
1417-1425,
1989.
37.
Zierhut, W,
Zimmer HG,
and
Gerdes AM.
Effect of angiotensin converting enzyme inhibition on pressure-induced left ventricular hypertrophy in rats.
Circ Res
69:
609-617,
1991.
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