Skip Navigation

Cardiovascular Research 2001 52(3):468-476; doi:10.1016/S0008-6363(01)00431-X
© 2001 by European Society of Cardiology
This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Barolet, A. W
Right arrow Articles by Strauss, B. H
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Barolet, A. W
Right arrow Articles by Strauss, B. H
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 2001, European Society of Cardiology

Administration of exogenous endothelin-1 following vascular balloon injury: early and late effects on intimal hyperplasia

Alan W Barolet1, Saeid Babaei1, Ranga Robinson, Pierre Picard, Winston Tsui, Nafiseh Nili, Farida Mohamed, Olga Ornatsky, John D Sparkes, Duncan J Stewart and Bradley H Strauss*

Division of Cardiology, Terrence Donnelly Heart Center, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada M5B 1W8

straussb{at}smh.toronto.on.ca

* Corresponding author. Tel.: +1-416-864-5913; fax: +1-416-864-5978

Received 19 March 2001; accepted 5 July 2001


   Abstract
Top
 Abstract
1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
 References
 
Administration of exogenous endothelin-1 (ET-1) has been shown to stimulate neointimal hyperplasia following arterial balloon angioplasty (BA). However, the specific effects of ET-1 on the cellular and extracellular matrix response of the vessel wall after balloon injury and the persistence of these ET-1 effects have not been studied. The objectives of this study were to determine the acute (1 week) and long term (10 weeks) effects of administering exogenous ET-1 after arterial BA on neointimal hyperplasia, collagen synthesis and content, cellular proliferation, and ETA and ETB receptor expression. Thirty-one rabbits were randomized to receive subcutaneous ET-1 (500 pmol/kg/day for 1 week) or placebo time-release pellets and sacrificed at either 1 or 10 weeks after BA. At 1 week, there was a significant two-fold increase in intimal cross-sectional area (CSA) in ET-1 treated animals compared with placebo. ET-1 treated animals showed significant increases in collagen synthesis (ten-fold) and collagen content (three-fold) compared to placebo treated animals. ET-1 treated animals also had a significant increase (two-fold) in proliferation rates. In addition, ETA and ETB receptor expression were significantly upregulated in ET-1 treated animals. By 10 weeks these stimulatory effects on intimal CSA and collagen content were no longer evident with a ‘catch up’ phenomenon observed in the placebo treated animals. Similarly, ETA and ETB mRNA levels had declined significantly in both groups. Therefore, exogenous ET-1 acutely stimulates extracellular and cellular processes including increased expression of ETA and ETB receptors contributing to intimal hyperplasia. However, these effects are transient and not maintained long term after withdrawal of exogenous ET-1 stimulation.

KEYWORDS Angioplasty; Arteries; Connective tissue; Endothelins; Extracellular matrix; Remodeling; Restenosis


   1. Introduction
Top
 Abstract
 1. Introduction
2. Materials and methods
 3. Results
 4. Discussion
 References
 
A number of cytokines and growth factors have been implicated in the pathogenesis of the arterial response to balloon angioplasty (BA) injury. Endothelin-1 (ET-1) is a 21 amino acid peptide that stimulates both cell proliferation [1–3] and collagen synthesis in cultured smooth muscle cells (SMC) [4]. In vivo studies have shown that ET-1 infusion increases intimal hyperplasia after balloon injury in the rat model [5–7]. However, it is not known whether the intimal thickening is due to a cellular and/or an extracellular matrix effect. Moreover, the persistence of this effect on intimal hyperplasia after withdrawal of exogenous ET-1 is unknown. The objectives of this study were to characterize the mechanisms of ET-1 stimulated intimal hyperplasia by: (1) identifying the early and late in vivo effects of a brief (1 week) ET-1 administration on intimal hyperplasia, collagen metabolism and cell proliferation; and (2) assessing the effects of exogenous ET-1 on the expression of molecular components of the intrinsic ET-1 system in the vessel wall, namely preproET-1 and the two receptor subtypes ETA and ETB.


   2. Materials and methods
Top
 Abstract
 1. Introduction
 2. Materials and methods
3. Results
 4. Discussion
 References
 
2.1 Model
The animal experiments were performed in accordance with guidelines set out by the University of Toronto and approved by the St. Michael’s Hospital Animal Care Committee. We used a double-balloon normolipemic injury model in 34 male New Zealand White rabbits weighing 3.6–3.8 kg as previously described [8]. The initial 3 cm of both common iliac arteries immediately distal to the aortic bifurcation underwent dilation with a 30 mm length, 3.0 mm diameter BA catheter. After recovery, the rabbits were fed regular rabbit chow and water ad libitum. BA of both iliac arteries (injury #2) was repeated 3 weeks later. Immediately after injury #2, a time-release pellet (Innovative Research of America, Sarasota, FL), containing either ET-1 (500 pM/kg/day for 7 days) or placebo, was implanted subcutaneously. This dose was based on a previously published rat data which showed maximal effects on intimal hyperplasia without affecting blood pressure [5]. In selected animals, blood samples were taken immediately and at 1, 2, 4, 7 and 14 days after pellet placement for measurement of plasma ET-1 levels. Animals were killed with a fatal injection of sodium pentobarbital at either 1 week or 10 weeks after the second injury. The iliac arteries were then isolated and removed. The proximal 1.5 cm segments of the iliac arteries were used for the collagen and mRNA studies. The distal 1.5 cm segments were fixed in 4% paraformaldehyde and used for histology.

2.2 Histopathology and morphometric analysis
Intimal cross-sectional area (CSA) was measured in Movat-pentachrome-stained sections by a computerised morphometric system (C-Imaging, Model 640, Compix). Cell number and overall cell density were assessed on hematoxylin/eosin stained sections as previously described [8].

2.3 Collagen measurements
Collagen synthesis and content measurements were performed in the proximal segment of the injured right iliac artery using a 14C–hydroxyproline assay, as previously described [8]. Results of collagen synthesis and content were expressed per arterial segment.

2.4 Indices of cell proliferation
In 10 animals that were sacrificed at 1 week, 300 mg bromodeoxyuridine (BrdU, Sigma), a thymidine analog, was injected subcutaneously at 24 and 12 h prior to sacrifice to assess cell proliferation. A monoclonal anti-BrdU antibody (Dako) was used as the primary antibody (1:50 dilution), as previously described [8]. Totals labeled cells were counted under 40x magnification.

2.5 Measurement of preproendothelin-1 mRNA by reverse transcription-polymerase chain reaction (RT-PCR)
RNA was extracted from the proximal segment of the injured left iliac artery using a standard guanidinium isothiocyanate phenol–chloroform extraction procedure as previously described [9]. Two micrograms of the total RNA was reverse transcribed using Moloney Murine Leukemia Virus Reverse Transcriptase (MMLV-RT, Life Technologies) and random primers in a total volume of 20 µl. Five microlitres of the reverse transcription mixture was used for the amplification of preproendothelin-1 (ppET-1) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in a polymerase chain reaction (PCR) using either 90 or 50 pM each of rabbit ppET-1 or human GAPDH sense and antisense primers, respectively. The ppET-1 primers were designed to generate a 506 bp fragment while the GAPDH primers generated a 343 bp fragment by PCR. The PCR procedure was carried out with an initial denaturation step for 5 min at 94°C followed by 40 cycles for ppET-1 or 25 cycles for GAPDH of 1 min denaturation at 94°C, 1 min annealing at 60°C and 1 min extension at 72°C. The intensity of ppET-1 bands was assessed relative to their respective GAPDH band density.

2.6 ETA and ETB receptor
2.6.1 Quantitative RT-PCR
ETA and ETB receptor mRNA levels were assessed by quantitative-competitive reverse transcriptase polymerase chain reaction (qcRT-PCR) as previously described by our group [10]. Briefly, four serial dilutions of both ETA and ETB mutants (10–17.5–10–16 M) were used to compete 2 µg of total RNA extracted from the iliac arteries. The reaction mixture (containing the sample and either the specific ETA receptor competitor (232 bp) or the ETB receptor competitor (448 bp) were reverse transcribed. The reaction products were electrophoresed on a vertical Novex system, and stained with ethidium bromide for visualization under high-energy ultra-violet radiation. The intensity of the wild-type and competitor bands at each dilution of the competitor was quantified by densitometry (GS-700, Bio-Rad, Mississauga, Canada) and then plotted as a graph of log ratio (wild-type/competitor) versus log [competitor cRNA]. The exact amount of ETA and ETB receptor mRNA present in each sample was then calculated from the graph by intrapolating the log [competitor cRNA] where the log ratio (wild-type/competitor) is zero (i.e. molar equivalence of wild-type and competitor cRNA). This assay has been validated in several species, including rabbits [10].

2.6.2 Immunostaining with confocal microscopy
Paraformalin fixed paraffin-embedded serial sections (6 µm thickness) were deparaffinized and incubated for 30 min in 0.1% Saponin/phosphate buffered saline (PBS)/1% bovine serum albumin (BSA) to permeabilize cellular membranes. Primary protein-G purified sheep anti-ETA and anti-ETB antibodies (Research Diagnostics Inc, Flanders, NJ) were used at 1:50 dilution. After overnight incubation, endothelin receptors were visualized using FITC-labeled anti-sheep IgG (Sigma). Cell nuclei were counterstained with ethidium bromide at 1 µg/ml for 2 min. Negative controls were done using non-immune sheep serum in the primary incubation. Images were examined on a Bio-Rad MRC-600 laser-scanning confocal imaging system equipped with the Bio-Rad COMOS operating software.

2.7 Endothelin-1 ELISA
Plasma endothelin-1 levels were measured using a commercial enzyme immunoassay kit (Biomedica Group, American Laboratory Products Company).

2.8 Statistical methods
Values are presented as mean±S.E.M. Data were analysed by ANOVA followed by Student t-test. Non-parametric data are presented as median (range) and were analysed by Mann–Whitney U-test. Results with P<0.05 were considered statistically significant.


   3. Results
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
4. Discussion
 References
 
3.1 In vivo studies
A total of 34 rabbits were used in the study. Three perioperative deaths occurred from surgical complications at the time of the second angioplasty (one placebo, two ET-1). Twenty animals (five animals/treatment group/time point) were initially included in the histology, collagen and mRNA assays. Eleven animals (eight ET-1, three placebo) were later included for the determination of ET-1 plasma levels and additional RNA studies. In animals sacrificed at 1 week following the second injury and placement of the ET-1 pellet, there were no differences in blood pressure compared to placebo treated animals or compared to the blood pressure measurements recorded at the time of the angioplasty procedure (data not shown). There were no baseline differences in plasma ET-1 levels before the angioplasty between the two groups (ET-1: 2.24±0.08 fM/ml, placebo: 2.18±0.08 fM/ml, P=ns). The peak plasma ET-1 levels occurred during the first 4 days after the balloon injury with a return to baseline ET-1 levels at 7 days. Peak plasma ET-1 levels were modestly increased in ET-1 treated animals compared to placebo treated animals (3.08±0.22 vs. 2.55±0.16 fM/ml, P=0.08).

3.2 Histopathology and morphometric analysis
At 1 week after injury #2 and pellet insertion, there was a significant increase in intimal CSA in ET-1 treated animals compared with placebo (0.87±0.15 vs. 0.44±0.04 mm2, P=0.041) (Fig. 1A and B: panels a and b). This was associated with an increase in the ratio of intima/media in the ET-1 treated animals compared to placebo (2.68±0.54 vs. 1.21±0.16, P<0.04). There were no significant differences in medial or adventitial CSA between the two groups. At 10 weeks, there were no differences in intimal, medial or adventitial CSA between ET-1 treated and placebo treated rabbits (Fig. 1A and B: panels c and d).


Figure 1
Figure 1
View larger version (145K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 1 (A) Intimal cross-section area changes in the ET-1 and placebo treated animals at 1 and 10 weeks. (B) Movat-pentachrome-stained sections showing representative examples of placebo treated (panel a: 1 week; panel c: 10 weeks) and ET-1 treated (panel b: 1 week; panel d: 10 weeks). A: adventitia; M: media; I: intima; L: lumen.

 
3.3 Collagen analysis
At 1 week post injury #2, collagen synthesis was significantly increased approximately 10-fold in ET-1 treated animals compared to placebo treated animals (median: 6867 [range: 5943–13 069] vs. 594 [168–2034] cpm 14C–hydroxyproline/arterial segment, P<0.01) (Table 1)). This was associated with a >two-fold increase in collagen content (median: 300 [range: 280–312] vs. 110 [54–279] µg hydroxyproline/arterial segment, P<0.01) (Table 1). Placebo treated animals demonstrated a three-fold increase in collagen content at 10 weeks post angioplasty compared to 1 week period, while no differences occurred in ET-1 treated animals over the same time. At 10 weeks, there were also no significant differences in either collagen content or synthesis between ET-1 treated and placebo treated animals.


View this table:
[in this window]
[in a new window]

  		Table 1 In vivo collagen synthesis and content per arterial segment

 
3.4 Proliferation indices and cell density
There were significant increases in both intimal and medial cell proliferation in ET-1 treated animals (n=7 arteries) compared with placebo treated animals (n=9 arteries) at 1 week (Fig. 2). The ET-1 treated animals demonstrated a significantly reduced intimal cell density at 1 week compared with placebo treated animals (median: 3323 [range: 2208–4382] vs. 4343 [3015–8345], P<0.02). At 10 weeks, there were no significant differences in intimal cell density between ET-1 and placebo treated animals (median: 4047 [2095–4982] vs. 3857 [2589–6971]).


Figure 2
View larger version (18K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 2 Increased intimal and medial cell proliferation in ET-1 treated animals compared with placebo treated animals at 1-week. * P<0.01.

 
3.5 PreproET-1 mRNA levels
PreproET-1 mRNA was detectable in the vessel wall at 1 week in both placebo and ET-1 treated rabbits (Fig. 3). At 10 weeks, ET-1 expression was barely detectable in either ET-1 or placebo treated rabbits.


Figure 3
View larger version (81K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 3 RT-PCR of rabbit iliac arteries, with the top and bottom panels showing the expression of preproET-1 and GAPDH mRNA, respectively, in 1-week ET-1 treated (lane 1), 1-week placebo (lane 2), 10-week ET-1 treated (lane 3) and 10 week placebo (lane 4). Lane 8 is an uninjured control. Rabbit lung was used as a positive control (lane 6) and viral RNA as a negative control (lane 7). {varphi}X174/Hae III DNA markers were run in lane 5. The 1-week ET-1 treated and placebo arteries exhibited no differences in their expression of ppET-1, whereas ppET-1 was barely detectable at 10-weeks in either ET-1 treated or placebo arteries.

 
3.6 Endothelin receptors
At 1 week, both ETA receptor mRNA and ETB receptor mRNA were significantly increased (approximately four-fold) in ET-1 treated animals compared to placebo treated animals (Table 2, Fig. 4). By 10 weeks, there was a marked and significant downregulation (approximately 90%) of both ETA and ETB receptor mRNA levels in both groups compared to 1 week. There were no significant differences at 10 weeks between ET-1 treated and placebo treated animals for ETA mRNA levels although ETB receptors mRNA levels were still two-fold higher in ET-1 treated animals (P<0.05).


View this table:
[in this window]
[in a new window]

  		Table 2 ETA and ETB receptor mRNA expression

 

Figure 4
View larger version (32K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 4 qcRT-PCR analysis showing ETA and ETB receptor mRNA expression in ET-1 treated and placebo treated animals at 1 and 10 weeks. Four serial dilutions of both ETA and ETB mutants (10–17.5–10–16 M) were used to compete 2 µg of total RNA extracted from the iliac arteries (see text for details). Concentration for competitor (C) (log M) and samples (S) (µg of total RNA) are indicated for each lane. In this representative analysis, increased ETA and ETB receptor mRNA expression were present in the ET-1 treated animals at 1-week (upper right and left panels). However, by 10 weeks, there were marked downregulation of ETA and ETB receptor mRNA expression in both ET-1 and placebo treated animals (lower right and left panels).

 
Analysis of confocal microscopy images also demonstrated increased immunostaining for ETA receptors in the intimal SMCs at 1 week in ET-1 treated animals compared to placebo treated animals (Fig. 5). Similar results were seen for ETB receptors (data not shown). At 10 weeks there was substantially less immunostaining for ETA and ETB receptors with no appreciable differences between the ET-1 and placebo treated groups (data not shown).


Figure 5
View larger version (50K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 5 Confocal microscopy showing increased immunostaining for ETA receptors in the intimal SMCs at 1-week in ET-1 treated animals (panel B) compared to placebo treated animals (panel A). The submembrane localization of the ETA receptors is indicated by the yellow colour in cells that are counterstained red with ethidium bromide. Non-immune sheep serum as a negative control (panel C). The internal elastic lamina (IEL) demonstrates green autofluorescence. m: media; i: intima.

 

   4. Discussion
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
References
 
Endothelin has been implicated in the pathogenesis of restenosis after balloon injury. Elevated ET-1 plasma levels have been reported in patients following coronary angioplasty [11]. In various animal models, selective antagonism of the ETA receptor [12] or by a non-selective ET antagonist attenuates neointimal formation by approximately 35–50% following balloon or stent injury [5,13–19]. However, the analyses of these studies have been restricted to measurements of intimal areas and have not addressed the mechanisms by which ET-1 causes its effects. Therefore, we performed this detailed study of the cellular and extracellular matrix (ECM) responses to ET-1 administration in a rabbit iliac artery injury model.

The main finding of our study is that exogenous ET-1 promotes intimal thickening by increased collagen synthesis and content and to a lesser degree by stimulation of cell proliferation. The ECM effects appeared to predominate since collagen synthesis increased ten-fold, while cell proliferation demonstrated a more modest two-fold increase in ET-1 treated rabbits at 1 week. Furthermore, intimal cell density at 1 week post balloon injury was significantly decreased in the ET-1 treated group, suggesting a disproportionate increase in ECM accumulation relative to the increase in intimal cells. The second significant finding was that these ET-1 effects were mediated by increased expression of both ETA and ETB receptors in the vessel wall. The third novel observation of this study was the transient effects of exogenous ET-1 on the intimal thickening. Despite dramatic increases in collagen accumulation, SMC proliferation and endothelin receptor expression at 1 week in ET-1 treated animals, these effects did not persist. The placebo treated animals, which are also exposed to endogenously released growth factors and cytokines, demonstrated a similar but somewhat delayed healing pattern as the ET-1 supplemented animals with eventual ‘catch up’ by 10 weeks after the procedure.

Our data support ET-1 as an important mediator of ECM response after balloon injury. This particular function of ET-1 is consistent with its ECM stimulatory effects on cultured SMC and in various human diseases. In vitro studies of porcine SMC have shown that ET-1 stimulates synthesis of procollagen type I and III, an effect that can be inhibited by pretreatment with a selective ETA antagonist [4]. Several diseases have been identified that are associated with enhanced endothelin activity including scleroderma [20], pulmonary hypertension [21,22], pulmonary fibrosis [23], nephroangiosclerosis [24], hepatic fibrosis [25], and cardiac hypertrophy [26,27]. Similar to our finding in arterial balloon injury [28], in all of these conditions, the pathogenic role of ET-1 relies at least in part on aberrant local collagen deposition. At the progressive stage of pulmonary hypertension in monocrotaline-treated rats, both ET-1 levels and its mRNA expression in the lung increased in parallel with an increase in total collagen accumulation [22]. ET-1 also plays an important role on the progression of experimental glomerulonephritis [29]. Exogenous ET-1 stimulates mesangial synthesis of ECM components such as type I, III and IV collagen, laminin, fibronectin, and tenascin [30,31]. While a consistent relationship between ET-1 and enhanced ECM synthesis has been reported, several studies have shown rather variable effects of ET-1 on SMC proliferation, ranging from potent stimulation [4,32,33] to no effect [34,35].

4.1 ETAand ETB expression after exogenous ET-1 and balloon injury
The biological effects of ETs are mediated by two different receptor subtypes, ETA and ETB [35–37]. In the vessel wall, the ETA receptor is located most abundantly on SMC, whereas the ETB receptor is found mainly on the endothelial layer and to a much lesser extent on SMC. Two mechanisms have been postulated regarding the actions of ET-1 on ECM synthesis. ET-1 could either act directly at the transcriptional level of ECM genes or indirectly via induction of potent growth factors such as TGFβ [38]. A novel observation of this study is that both ETA and ETB receptor mRNA and protein levels were upregulated in the ET-1 treated animals compared to placebo treated animals at 1 week after balloon angioplasty. This increased ET receptor expression may be another important mechanism contributing to the ECM response. Upregulation of endothelin receptors has been previously reported in the carotid artery balloon injury model [6,28,39] and in scleroderma-associated fibrotic lung disease [40], two conditions associated with increased endogenous plasma levels of ET-1. Our data suggest that there may be in fact a causal relationship between ET-1 and endothelin receptor expression.

4.2 Relationship of our results to previous studies of exogenous ET-1
Another significant finding of our study is that the lack of persistent effect following withdrawal of exogenous ET-1, suggesting that the usual formation of intimal hyperplasia was accelerated at 1 week in ET-treated animals but not at 10 weeks. At 10 weeks, there was barely detectable ET-1 mRNA expression in the vessel wall in both ET-1 and placebo treated animals. The enhanced expression of ET receptor mRNA levels in the vessel wall also did not persist, and in fact had significantly declined by 10 weeks. Neointimal CSA and vessel wall collagen content were at similar levels in both groups, reflecting an increase over the 9-week time period in the placebo treated animals with minimal change in the ET-1 treated animals. Since the effect of prolonging the exogenous ET-1 administration was not assessed, it is unclear whether the maximum intimal response was reached at an earlier time period in the 1 week ET-1 treated animals or if additional intimal hyperplasia would have continued with ongoing exogenous ET-1 stimulation. This is the first study to assess the late effects of withdrawing ET-1 stimulation. Previous work by our group and others have indicated that balloon injury alone transiently increases mRNA levels for preproET-1 and both ETA and ETB receptors in the first 7 days following balloon injury [28,39]. A single dose of exogenous ET-1 (up to 500 pmol/kg immediately after BA) dose-dependently augmented the degree of neointimal formation (by up to 150%) at 14 days in a rat carotid injury model [5] but later time points were not assessed.

In summary, our data suggest an important role of ET-1 in upregulating the ECM and cellular proliferative responses that contributes to intimal hyperplasia after balloon injury. Differences in endogenous ET-1 expression and persistence of that expression may account for some of the variability in vessel wall repair and restenosis. It remains to be shown whether inhibition of ET-1 effects will significantly impact on restenosis, particularly since our study found no late differences in intimal CSA and vessel wall collagen after withdrawal of exogenous ET-1.

Time for primary review 25 days.


   Acknowledgements
 
This work was supported by a grant from the Heart and Stroke Foundation of Ontario, St. Michael’s Hospital Research Council and a generous donation from the estate of Mrs. Barbara Miller.


   Notes
 
1 Contributed equally to this work. Back


   References
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
 References
 

  1. Kanse S.M., Wijelath E., Kanthou C., Newman P., Kakkar V.V. The proliferative responsiveness of human vascular smooth muscle cells to endothelin correlates with endothelin receptor density. Lab Invest (1995) 72:376–382.[Web of Science][Medline]
  2. Weber H., Webb M.L., Serafino R., Taylor D.S., Moreland S., Norman J., Molloy C.J. Endothelin-1 and angiotensin-II stimulate delayed mitogenesis in cultured rat aortic smooth muscle cells: evidence for common signaling mechanisms. Mol Endocrinol (1994) 8:148–158.[Abstract/Free Full Text]
  3. Lonchampt M.O., Pinelis S., Goulin J., Chabrier P.E., Braquet P. Proliferation and Na+/H+ exchange activation by endothelin in vascular smooth muscle cells. Am J Hypertens (1991) 4:776–779.[Web of Science][Medline]
  4. Rizvi M.A., Katwa L., Spadone D.P., Myers P.R. The effects of endothelin-1 on collagen type I and type III synthesis in cultured porcine coronary artery vascular smooth muscle cells. J Mol Cell Cardiol (1996) 28:243–252.[CrossRef][Web of Science][Medline]
  5. Douglas S.A., Louden C., Vickery-Clark L.M., Storer B.L., Hart T., Feuerstein G.Z., Elliott J.D., Ohlstein E.H. A role for endogenous endothelin-1 in neointimal formation after rat carotid artery balloon angioplasty. Protective effects of the novel nonpeptide endothelin receptor antagonist SB 209670. Circ Res (1994) 75:190–197.[Abstract/Free Full Text]
  6. Douglas S.A., Ohlstein E.H. Endothelin-1 promotes neointima formation after balloon angioplasty in the rat. J Cardiovasc Pharmacol (1993) 22(Suppl_8):S371–S373.[CrossRef][Web of Science][Medline]
  7. Trachtenberg J.D., Sun S., Choi E.T., Callow A.D., Ryan U.S. Effect of endothelin-1 infusion on the development of intimal hyperplasia after balloon catheter injury. J Cardiovasc Pharmacol (1993) 22(Suppl 8):S355–S359.[CrossRef][Web of Science][Medline]
  8. Strauss B.H., Chisholm R.J., Keeley F.W., Gotlieb A.I., Logan R.A., Armstrong P.W. Extracellular matrix remodeling after balloon angioplasty injury in a rabbit model of restenosis. Circ Res (1994) 75:650–658.[Abstract/Free Full Text]
  9. Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate–phenol–chloroform extraction. Anal Biochem (1987) 162:156–159.[Web of Science][Medline]
  10. Smith P.J., Brooks J.I., Stewart D.J., Monge J.C. Quantification of endothelin ETA and ETB receptor mRNA by competitive reverse transcription-polymerase chain reaction: development of a multispecies assay. Anal Biochem (1999) 271:93–96.[CrossRef][Web of Science][Medline]
  11. Tahara A., Kohno M., Yanagi S., Itagane H., Toda I., Akioka K., Teragaki M., Yasuda M., Takeuchi K., Takeda T. Circulating immunoreactive endothelin in patients undergoing percutaneous transluminal coronary angioplasty. Metabolism (1991) 40:1235–1237.[CrossRef][Web of Science][Medline]
  12. Douglas S.A., Vickery-Clark L.M., Louden C., Ohlstein E.H. Selective ETA receptor antagonism with BQ-123 is insufficient to inhibit angioplasty induced neointima formation in the rat. Cardiovasc Res (1995) 29:641–646.[Abstract/Free Full Text]
  13. Ferrer P., Valentine M., Jenkins-West T., Weber H., Goller N.L., Durham S.K., Molloy C.J., Moreland S. Orally active endothelin receptor antagonist BMS-182874 suppresses neointimal development in balloon-injured rat carotid arteries. J Cardiovasc Pharmacol (1995) 26:908–915.[Web of Science][Medline]
  14. Chandra S., Clark L.V., Coatney R.W., Phan L., Sarkar S.K., Ohlstein E.H. Application of serial in vivo magnetic resonance imaging to evaluate the efficacy of endothelin receptor antagonist SB 217242 in the rat carotid artery model of neointima formation. Circulation (1998) 97:2252–2258.[Abstract/Free Full Text]
  15. McKenna C.J., Burke S.E., Opgenorth T.J., Padley R.J., Camrud L.J., Camrud A.R., Johnson J., Carlson P.J., Lerman A., Holmes D.R. Jr., Schwartz R.S. Selective ET(A) receptor antagonism reduces neointimal hyperplasia in a porcine coronary stent model. Circulation (1998) 97:2551–2556.[Abstract/Free Full Text]
  16. Burke S.E., Lubbers N.L., Gagne G.D., Wessale J.L., Dayton B.D., Wegner C.D., Opgenorth T.J. Selective antagonism of the ET(A) receptor reduces neointimal hyperplasia after balloon-induced vascular injury in pigs. J Cardiovasc Pharmacol (1997) 30:33–41.[CrossRef][Web of Science][Medline]
  17. Dashwood M.R., Noertersheuser P., Kirchengast M., Munter K. Altered endothelin-1 binding following balloon angioplasty of pig coronary arteries: effect of the ETA receptor antagonist, LU 135252. Cardiovasc Res (1999) 43:445–456.[Abstract/Free Full Text]
  18. Takiguchi Y., Sogabe K. The selective endothelin ETA receptor antagonist FR139317 inhibits neointimal thickening in the rat. Eur J Pharmacol (1996) 309:59–62.[CrossRef][Web of Science][Medline]
  19. Azuma H., Sato J., Masuda H., Goto M., Tamaoki S., Sugimoto A., Hamasaki H., Yamashita H. ATZ1993, an orally active and novel nonpeptide antagonist for endothelin receptors and inhibition of intimal hyperplasia after balloon denudation of the rabbit carotid artery. Jpn J Pharmacol (1999) 81:21–28.[CrossRef][Medline]
  20. Kahaleh M.B. Endothelin, an endothelial-dependent vasoconstrictor in scleroderma. Enhanced production and profibrotic action. Arthritis Rheum (1991) 34:978–983.[Web of Science][Medline]
  21. Dupuis J., Prie S. The ET(A)-receptor antagonist LU 135252 prevents the progression of established pulmonary hypertension induced by monocrotaline in rats. J Cardiovasc Pharmacol Ther (1999) 4:33–39.[Abstract/Free Full Text]
  22. Mansoor A.M., Honda M., Saida K., Ishinaga Y., Kuramochi T., Maeda A., Takabatake T., Mitsui Y. Endothelin induced collagen remodeling in experimental pulmonary hypertension. Biochem Biophys Res Commun (1995) 215:981–986.[CrossRef][Web of Science][Medline]
  23. Giaid A., Michel R.P., Stewart D.J., Sheppard M., Corrin B., Hamid Q. Expression of endothelin-1 in lungs of patients with cryptogenic fibrosing alveolitis. Lancet (1993) 341:1550–1554.[CrossRef][Web of Science][Medline]
  24. Tharaux P.L., Chatziantoniou C., Casellas D., Fouassier L., Ardaillou R., Dussaule J.C. Vascular endothelin-1 gene expression and synthesis and effect on renal type I collagen synthesis and nephroangiosclerosis during nitric oxide synthase inhibition in rats. Circulation (1999) 99:2185–2191.[Abstract/Free Full Text]
  25. Rockey D.C., Chung J.J. Endothelin antagonism in experimental hepatic fibrosis. Implications for endothelin in the pathogenesis of wound healing. J Clin Invest (1996) 98:1381–1388.[Web of Science][Medline]
  26. Hocher B., George I., Rebstock J., Bauch A., Schwarz A., Neumayer H.H., Bauer C. Endothelin system-dependent cardiac remodeling in renovascular hypertension. Hypertension (1999) 33:816–822.[Abstract/Free Full Text]
  27. Harada M., Itoh H., Nakagawa O., Ogawa Y., Miyamoto Y., Kuwahara K., Ogawa E., Igaki T., Yamashita J., Masuda I., Yoshimasa T., Tanaka I., Saito Y., Nakao K. Significance of ventricular myocytes and nonmyocytes interaction during cardiocyte hypertrophy: evidence for endothelin-1 as a paracrine hypertrophic factor from cardiac nonmyocytes. Circulation (1997) 96:3737–3744.[Abstract/Free Full Text]
  28. Picard P., Smith P.J., Monge J.C., Stewart D.J. Expression of endothelial factors after arterial injury in the rat. J Cardiovasc Pharmacol (1998) 31(Suppl 1):S323–S327.[CrossRef][Web of Science][Medline]
  29. Benigni A., Remuzzi G. Endothelin in the progressive renal disease of glomerulopathies. Miner Electrolyte Metab (1995) 21:283–291.[Web of Science][Medline]
  30. Hahn A.W., Resink T.J., Kern F., Buhler F.R. Peptide vasoconstrictors, vessel structure, and vascular smooth-muscle proliferation. J Cardiovasc Pharmacol (1993) 22(Suppl 5):S37–S43.
  31. Orisio S., Zoja C., Remuzzi G. The role of endothelin in the progression of the renal disease in an experimental model of chronic kidney failure. Ann Ital Med Int (1993) 8:213–217.[Medline]
  32. Hirata Y., Takagi Y., Fukuda Y., Marumo F. Endothelin is a potent mitogen for rat vascular smooth muscle cells. Atherosclerosis (1989) 78:225–228.[CrossRef][Web of Science][Medline]
  33. Komuro I., Kurihara H., Sugiyama T., Yoshizumi M., Takaku F., Yazaki Y. Endothelin stimulates c-fos and c-myc expression and proliferation of vascular smooth muscle cells. FEBS Lett (1988) 238:249–252.[CrossRef][Web of Science][Medline]
  34. Scott-Burden T., Resink T.J., Hahn A.W., Vanhoutte P.M. Induction of endothelin secretion by angiotensin II: effects on growth and synthetic activity of vascular smooth muscle cells. J Cardiovasc Pharmacol (1991) 17(Suppl 7):S96–100.[Web of Science][Medline]
  35. Jahan H., Kobayashi S., Nishimura J., Kanaide H. Endothelin-1 and angiotensin II act as progression but not competence growth factors in vascular smooth muscle cells. Eur J Pharmacol (1996) 295:261–269.[CrossRef][Web of Science][Medline]
  36. Arai H., Hori S., Aramori I., Ohkubo H., Nakanishi S. Cloning and expression of a cDNA encoding an endothelin receptor. Nature (1990) 348:730–732.[CrossRef][Medline]
  37. Sakurai T., Yanagisawa M., Takuwa Y., Miyazaki H., Kimura S., Goto K., Masaki T. Cloning of a cDNA encoding a non-isopeptide-selective subtype of the endothelin receptor. Nature (1990) 348:732–735.[CrossRef][Medline]
  38. Nakamura T., Ebihara I., Fukui M., Tomino Y., Koide H. Effect of a specific endothelin receptor A antagonist on mRNA levels for extracellular matrix components and growth factors in diabetic glomeruli. Diabetes (1995) 44:895–899.[Abstract]
  39. Wang X., Douglas S.A., Louden C., Vickery-Clark L.M., Feuerstein G.Z., Ohlstein E.H. Expression of endothelin-1, endothelin-3, endothelin-converting enzyme-1, and endothelin-A and endothelin-B receptor mRNA after angioplasty-induced neointimal formation in the rat. Circ Res (1996) 78:322–328.[Abstract/Free Full Text]
  40. Abraham D.J., Vancheeswaran R., Dashwood M.R., Rajkumar V.S., Pantelides P., Xu S.W., du Bois R.M., Black C.M. Increased levels of endothelin-1 and differential endothelin type A and B receptor expression in scleroderma-associated fibrotic lung disease. Am J Pathol (1997) 151:831–841.[Abstract]

Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?



This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Barolet, A. W
Right arrow Articles by Strauss, B. H
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Barolet, A. W
Right arrow Articles by Strauss, B. H
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?