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(Circulation. 1995;91:941-947.)
© 1995 American Heart Association, Inc.

Articles

Tissue Endothelin-1 Immunoreactivity in the Active Coronary Atherosclerotic Plaque

A Clue to the Mechanism of Increased Vasoreactivity of the Culprit Lesion in Unstable Angina

Andreas M. Zeiher, MD; Heike Goebel, BSc; Volker Schächinger, MD; Christian Ihling, MD

From the Department of Internal Medicine III, Division of Cardiology (A.M.Z., H.G., V.S.), and the Department of Pathology (C.I.), University of Freiburg (Germany).

Correspondence to Andreas M. Zeiher, MD, Department of Internal Medicine III, Division of Cardiology, University of Freiburg, Hugstetterstr 55, D-79106 Freiburg, Germany.

	Abstract

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Background The pathomorphological substrate of complicated coronary atherosclerotic lesions underlying unstable angina is characterized by a localized chronic inflammatory process. Functionally, coronary lesions associated with unstable angina demonstrate an enhanced vasoreactivity. Endothelin-1 is a potent vasoconstrictor peptide produced not only by endothelial cells but also by macrophages and polymorphonuclear leukocytes, the cell types characteristic of inflammation.

Methods and Results By use of immunohistochemical techniques, we examined the presence of endothelin-1 in coronary atherosclerotic plaque tissue obtained by directional coronary atherectomy of primary lesions from 50 consecutive patients. The tissue specimens of 43 of 50 patients (86%) demonstrated endothelin-1–like immunoreactivity. Endothelin-1–like immunoreactivity preferentially localized to macrophage-rich areas, to hypercellular regions rich in microvessels, and to plaque areas with evidence of prior hemorrhage. Double-immunolabeling revealed that both macrophages (HAM56 positive) and intimal smooth muscle cells (-actin positive) demonstrated cytoplasmic immunostaining for endothelin-1. Semiquantitative analysis of endothelin-1–like immunostaining revealed significantly (P<.005) higher staining grades in active (1.86±0.15, n=40) compared with nonactive lesions (0.78±0.35, n=10): endothelin-1 staining grades were significantly (P<.001) lower in patients with stable angina (0.69±0.19, n=13) than in patients with crescendo angina (1.82±0.30, n=11), with angina at rest (2.08±0.21, n=12), or with angina after myocardial infarction (2.0±0.26, n=14).

Conclusions Endothelin-1 immunostaining of atherosclerotic tissue localizes predominantly with plaque components indicative of chronic inflammatory processes. The increased tissue endothelin-1–like immunoreactivity in active coronary atherosclerotic lesions may provide a clue to the mechanisms of increased vasoreactivity of the culprit lesion in acute ischemic syndromes, which is the clinical substrate of the active coronary atherosclerotic plaque.

Key Words: atherosclerosis • endothelin • angina • leukocytes • ischemia

	Introduction

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Plaque rupture, hemorrhage, and thrombus formation have been implicated as the mechanisms responsible for the transformation of stable coronary lesions into active lesions,^{1 2} leading to unstable angina, acute myocardial infarction, and sudden ischemic death. The pathomorphological substrate underlying a complicated lesion appears to be related to plaque composition.^{1 3} Although plaque morphology is heterogeneous with respect to plaque architecture and cellular composition, the presence of a localized inflammatory process is a characteristic consistently associated with plaque rupture.^{4 5}

The active coronary atherosclerotic lesion is characterized functionally by an abnormal vasoconstriction⁶ manifested as exaggerated constrictor responses to platelet mediators.⁷ Importantly, a recent study demonstrated that enhanced coronary vasoreactivity in unstable angina is confined to the culprit lesion,⁸ suggesting that enhanced vasoreactivity is a local plaque–related phenomenon rather than the consequence of systemically operative neurohumoral factors.

Endothelin-1 is one of a family of peptides that are potent constrictors of vascular smooth muscle.^{9 10} In addition to being a potent vasoconstrictor itself, endothelin-1 markedly potentiates the constrictor effects of other vasoconstrictor stimuli, such as catecholamines, serotonin, and angiotensin II.^{11 12 13} Interestingly, endothelin-1 is not only produced by endothelial cells but also by human macrophages¹⁴ and polymorphonuclear leukocytes,¹⁵ suggesting a role for endothelin-1 in inflammatory processes.

Thus, the present study was designed to examine the presence of endothelin-1 in the active coronary atherosclerotic plaque as a potential clue to the mechanism of increased vasoreactivity of the culprit lesion in unstable angina.

	Methods

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Patients
Atherosclerotic lesions from 50 consecutive patients undergoing percutaneous revascularization for the first time (primary lesions) between August 1992 and May 1994 were analyzed. Atherectomy specimens were retrieved by therapeutic directional coronary atherectomy with the Simpson AtheroCath (DVI) according to previously described techniques.¹⁶ Patients with evidence of significant narrowing (>75%) of a major epicardial artery and lesion anatomy suitable for directional atherectomy were included in the study. The mean age of the patients was 57±8 years; 8 were women and 42 were men. Lesions were located in the left anterior descending coronary artery in 40 patients, in the right coronary artery in 7, and in the left circumflex artery in 3. Thirteen patients had stable angina, defined as stable angina pectoris for at least 3 months before percutaneous revascularization; 11 had crescendo angina, defined as accelerated angina pectoris during the past 2 months; 12 had angina at rest, defined as angina pectoris occurring at rest within 5 days before percutaneous revascularization; and 14 had postinfarction angina, defined as angina pectoris within the first 3 weeks after an acute myocardial infarction. In all patients with acute ischemic syndromes, the culprit lesion was treated by directional atherectomy.

Tissue Preparation
All atherectomy specimens retrieved were fixed in 4% unbuffered formalin at the time of percutaneous revascularization. Tissue was dehydrated in graded series of alcohol and embedded in a paraffin block. Serial sections were stained for hematoxylin and eosin, elastica–van Gieson's stain, and Perls' iron stain (Prussian blue reaction). Serial unstained sections were used for immunohistochemistry.

Immunohistochemistry
Sections embedded in paraffin were cut and mounted on slides. The slides were dried overnight at 60°C, deparaffinized with graded concentrations of xylene and ethanol, and washed with 0.6% H₂O₂ in methanol for 30 minutes at room temperature to block endogenous peroxidase activity. Tissue was then incubated with 5% normal bovine serum for 10 minutes at room temperature to reduce nonspecific background staining and then with a rabbit polyclonal endothelin-1 antiserum diluted 1:250 (Peninsula) in humidified chambers for 2 hours at room temperature. The specificity of this antibody has been extensively validated in previous studies.^{17 18} All treated slides were then incubated with biotinylated secondary antibody at room temperature followed by incubation with avidin and biotinylated horseradish peroxidase complex (ABC method, Vector Labs). Peroxidase activity was visualized by 3-amino-9-ethylcarbazole. The sections were counterstained with hematoxylin. As a positive control for endothelin-1, human internal mammary artery sections with preserved endothelial cell layers were used; these sections gave the expected well-localized pattern within endothelial cells, with negative staining of subintimal and medial layers.

Cell types were determined in serial sections with monoclonal antibodies specific to either smooth muscle -actin (dilution, 1:1000; Sigma Immunochemicals) or macrophages (HAM56; dilution, 1:50; Enzo Diagnostics Inc).

Double-Label Immunohistochemistry
To identify specific cell types expressing endothelin-1–like immunoreactivity, double labeling was performed with endothelin-1 antibody and a cell-specific antibody. Briefly, the single-label procedure was performed as described above with 3-amino-9-ethylcarbazole to yield a brownish reaction product. In a second step, either -actin or HAM56 staining was performed with the alkaline phosphatase and monoclonal antialkaline phosphatase method.¹⁹ Activity of alkaline phosphatase was visualized with naphthol AS-MX phosphate (Sigma N 4875) and fast blue BB salt (Sigma F 3378) substrate solution to yield a blue reaction product. Activity of endogenous alkaline phosphatase was blocked by adding 0.01 mL of 1 mol/L levamisole (Sigma L 9756) to the substrate solution. Since it has been shown that HAM56 also recognizes endothelial cells, we used a different antibody specific for macrophages, CD68 (Dako), in experiments in which microvessels were present in the tissue specimens. In general, HAM56 and CD68 gave identical results except in some areas with neovascularization, in which HAM56 occasionally also stained endothelial cells of the microvessels.

Histochemical and Immunohistochemical Analysis
The specimens were analyzed by light microscopy for the presence of thrombus, old hemorrhage (positive Prussian blue reaction), atheromatous gruel surrounded by macrophages indicative of inflammatory processes, abundant and disorganized smooth muscle cells in the presence of loose connective tissue, and neovascularization. A lesion was classified as active if one or more of the criteria mentioned above were met. These sections were examined for the presence and localization of endothelin-1–like immunoreactivity. Comparative examination of serial sections permitted the assessment of colocalization of endothelin-1–like immunoreactivity with intimal smooth muscle cells (-actin positive) and macrophages (HAM56 or CD68 positive). Double labeling was used to confirm the simultaneous presence of both antigens in the cell cytoplasm, as indicated by a brownish and blue staining. In addition, endothelin-1 immunostaining intensity was graded semiquantitatively from 0 to 3: grade 0 indicated the absence of any staining; grade 1, endothelin-1 positivity associated with <10% of the cells; grade 2, positivity of 10% to 30% of the cells; and grade 3, positivity of >30% of the cells. Grading was performed independently by two of the investigators (H.G., C.I.) who were without knowledge of the clinical symptoms. The grades independently assigned by both observers agreed to within one grade; differences were resolved by joint examination.

Statistical Analysis
All data are reported as mean±SEM unless stated otherwise. One-way ANOVA followed by the Student-Newman test was used for statistical comparison. For dichotomous variables, we used Fisher's exact or the ² test. The exact two-sided Jonckheere-Terpstra test²⁰ was used to compare the distribution of different plaque characteristics within different patient groups. A value of P<.05 was considered statistically significant.

	Results

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Endothelin-1 Labeling
The specimens of 43 of the 50 patients (86%) contained material that was immunostainable for endothelin-1. Endothelin-1–like immunoreactivity was distributed focally, with a preferential localization to three histologically defined components of the plaque: macrophage-rich areas surrounding atheromatous gruel; hypercellular regions rich in microvessels adjacent to areas of macrophage infiltration; and areas with evidence of old hemorrhage, as evidenced by a positive Prussian blue reaction. Fig 1 illustrates the characteristic distribution of endothelin-1 immunoreactivity in a tissue specimen exhibiting all the criteria mentioned above. Endothelin-1 immunostaining appeared in two distinct patterns: cytoplasmic and diffuse extracellular staining (Fig 1). Diffuse extracellular staining was frequently observed in necrotic areas, suggesting that endothelin-1 was derived from previously injured or dead cells. In contrast, endothelin-1 immunostaining that localized to macrophages surrounding necrotic areas or to hypercellular areas of intimal smooth muscle cells was exclusively found in the cytoplasm. Fig 2 illustrates cytoplasmic endothelin-1 immunostaining in an area of abundant disorganized smooth muscle cells in the presence of loose connective tissue. Double-labeling confirmed that both macrophages and intimal smooth muscle cells demonstrated cytoplasmic immunostaining for endothelin-1 (Fig 3).

View larger version (0K): [in this window] [in a new window]   Figure 1. Serial sections of a representative atherosclerotic tissue specimen stained for intimal smooth muscle cells (-actin, A and B), macrophages (HAM56, C and D), and endothelin-1 (E, F, and G). Inserts in A, C, E, and F are shown in higher-power magnification in B, D, F, and G, respectively. Note preferential localization of endothelin-1–like immunoreactivity (brownish-red staining) to macrophages surrounding the necrotic area as well as to -actin–positive intimal smooth muscle cells in hypercellular regions rich in microvessels (G). G illustrates diffuse extracellular endothelin-1 staining in necrotic areas (right) and granular cytoplasmic staining in hypercellular regions with neovascularization (middle and left). For A, C, and E, original magnification x22; for B, D, and F, original magnification x87; for G, original magnification x350.

View larger version (0K): [in this window] [in a new window]   Figure 2. Photomicrographs showing serial sections of an atherosclerotic tissue specimen stained for intimal smooth muscle cells (-actin, A), endothelin-1–like immunoreactivity (B), and macrophages (HAM56, C). Note cytoplasmic endothelin-1–like immunostaining of disorganized intimal smooth muscle cells between loose connective tissue and sparsely scattered macrophages. (D indicates insert in B at higher-power magnification). For A, B, and C, original magnification x175; for D, original magnification x550.

View larger version (0K): [in this window] [in a new window]   Figure 3. Double immunolabeling for endothelin-1 (red reaction product) and intimal smooth muscle cells (-actin, blue reaction product, A) or macrophages (HAM56, blue reaction product, B), demonstrating cytoplasmic codistribution of endothelin-1–like immunoreactivity with both intimal smooth muscle cells (A) and macrophages (B). Original magnification x550.

In the vascularized regions, cells that appeared to be endothelial stained inconsistently for endothelin-1 (Fig 1G). However, extensive endothelin-1 immunostaining was found in hypercellular regions adjacent to microvessels and preferentially localized to areas of old hemorrhage, as evidenced by a positive Prussian blue reaction (Fig 4).

View larger version (0K): [in this window] [in a new window]   Figure 4. Serial sections of a neovascularized region of an atherosclerotic tissue specimen showing evidence for prior intraplaque hemorrhage (positive Prussian blue staining, A) and endothelin-1–like immunoreactivity (reddish-brown reaction product, B) in hypercellular regions (A and B, right) adjacent to microvessels and hemosiderin deposits. * indicates microvessels. Original magnification x350.

Endothelin-1 immunostaining was weak in hypocellular fibrotic regions and, whenever present, preferentially localized to scattered macrophages.

In 33 patients, the tissue specimens contained regions of necrotic gruel. Of these, 31 (94%) were also positive for endothelin-1–like immunoreactivity, whereas endothelin-1 immunostaining was observed in only 9 of 17 patients (53%) without necrotic material in their atherectomy specimens (P<.05). All atherectomy specimens with microvessels (those from 23 patients) were also positive for endothelin-1 immunostaining, whereas endothelin-1 staining was found in only 16 of 27 patients (59%) without neovascularization in their excised coronary atherosclerotic tissue (P<.05). Thirty of 35 (86%) patients with evidence of old hemorrhage had material immunostainable for endothelin-1, and in 9 of 15 patients (60%), endothelin-1 immunostaining was observed in the absence of a positive Prussian blue reaction (P=NS). Thrombi were found in the tissue specimens of 28 patients, of whom 23 (82%) were also positive for endothelin-1 staining, whereas 17 of 22 patients (77%) demonstrated endothelin-1 immunostaining without evidence of thrombotic material. The tissue specimens of 11 patients consisted predominantly of hypocellular fibrotic material, whereas 39 patients had either mixed or hypercellular lesions with a predominance of smooth muscle cells. Endothelin-1 immunostaining was detected in only 6 patients (55%) with fibrotic lesions (n=11) but in 37 of 39 patients (95%) with mixed or hypercellular lesions (P<.01).

Semiquantitative Analysis of Endothelin-1 Immunostaining
Fig 5 illustrates the mean endothelin-1 staining grades with respect to the presence or absence of different well-defined plaque components. The degree of endothelin-1 staining was significantly greater in lesions containing necrotic areas and neovascularization but significantly lower in predominantly hypocellular fibrotic lesions. On the basis of histological plaque components, the lesions of 40 patients were classified as active; the mean endothelin-1 staining grade was significantly (P<.005) higher in these active lesions (1.86±0.15) compared with a mean endothelin-1 staining grade of 0.78±0.35 (P<.005) in the nonactive lesions (n=10).

View larger version (30K): [in this window] [in a new window]   Figure 5. Endothelin-1 (ET-1) immunostaining grades (mean±SEM) in tissue specimens of atherosclerotic lesions with histological evidence for necrosis, hemorrhage, neovascularization (neovasc.), thrombus, and predominant hypocellularity (hypocellular).

Correlation of Endothelin-1 Staining With Clinical Symptoms
Fig 6 illustrates the endothelin-1 staining grades for each individual lesion in the four groups of patients with different anginal symptoms. Endothelin-1 staining grades were significantly (P<.001) lower in patients with stable angina (0.69±0.19) compared with patients with crescendo angina (1.82±0.30), with angina at rest (2.08±0.21), and with postinfarction angina (2.0±0.26). At the same time, lesion activity was significantly (P<.001) higher in the patients with crescendo angina and acute ischemic syndromes compared with patients with stable angina, as assessed by the distribution of the histological characteristics necrosis, thrombus, old hemorrhage, and neovascularization within the four groups with different anginal syndromes (Fig 7).

View larger version (12K): [in this window] [in a new window]   Figure 6. Endothelin-1 (ET-1) immunostaining grade for each individual lesion with respect to different anginal symptoms. Error bars indicate mean±SD. P<.001 for stable angina vs crescendo angina, angina at rest, and angina after myocardial infarction (post-MI).

View larger version (29K): [in this window] [in a new window]   Figure 7. Frequency distribution of different histological characteristics in the four groups of patients with different anginal syndromes. Post-MI indicates angina after myocardial infarction.

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
This study was designed to identify and quantify the content of endothelin-1–like immunoreactivity of human coronary atherosclerotic plaque tissue. The results reveal that the active coronary atherosclerotic plaque is characterized by the presence of significant amounts of tissue endothelin-1–like immunoreactivity. Endothelin-1 immunostaining localizes predominantly to areas with extensive macrophage infiltration and to hypercellular regions with evidence for neovascularization in the vicinity of atheromatous gruel. The association of tissue endothelin-1 immunoreactivity with plaque components indicative of chronic inflammatory responses suggests a role for local inflammatory processes in the production of endothelin-1 within atherosclerotic lesions.

A role for endothelin-1 in inflammation has been suggested by experimental findings that demonstrated that endothelin-1 production is induced by lipopolysaccharides in human macrophages¹⁴ and that endothelin-1 is synthesized and degraded by polymorphonuclear leukocytes.¹⁵ Moreover, increased tissue endothelin-1 levels have been observed in the submucosa of patients with chronic inflammatory bowel disease.²¹ Atherosclerosis is increasingly thought to be a chronic inflammatory disease^{22 23} characterized by foci of macrophages and T lymphocytes in the arterial wall, by the proliferation of vascular smooth muscle cells, and by matrix formation and neovascularization.²⁴ Previous studies in humans have shown the presence of endothelin-1–like immunoreactivity in vascular smooth muscle cells of the atherosclerotic aorta¹⁷ and an increase in endothelin-1 mRNA in atherosclerotic carotid lesions,²⁵ suggesting an activation of the endothelin-1 gene in atherosclerosis and providing a rational basis for the observation of increased plasma levels of endothelin-1 correlating with the severity of atherosclerosis.¹⁷ The present study is the first to assess endothelin-1–like immunoreactivity and its localization to specific cell types within the atherosclerotic plaque. Endothelin-1 immunostaining was most prominent in areas with evidence of macrophage infiltration. Macrophages are the principal inflammatory cells in atherosclerotic plaques, and their role as key mediators involved in the transition of stable atherosclerotic lesions into active lesions is well established.^{4 5} The results of the present study, demonstrating an association of endothelin-1 immunostaining with macrophage-rich plaque areas indicative of active inflammatory responses, provide compelling new evidence in support of the view that endothelin-1 not only is generally involved in inflammatory processes in vivo but also is particularly involved in active coronary atherosclerotic lesions.

A role for inflammatory processes in the expression of tissue endothelin-1 in atherosclerotic plaque is also supported by our findings that, in the vicinity of atheromatous gruel, increased tissue endothelin-1 immunoreactivity was observed in hypercellular regions with evidence for neovascularization, which are also characteristic histological features of a chronic inflammatory response. Macrophages not only contribute to the disruption of the atherosclerotic plaque but also secrete mitogenic factors leading to the proliferation of smooth muscle cells and stimulation of plaque neovascularization.^{1 26 27} The finding of an association of increased tissue endothelin-1 immunoreactivity with hypercellular areas rich in microvessels is intriguing. Previous studies implicated that microvessels may contribute to plaque evolution or complication by means of intraplaque hemorrhages.^{28 29} Dividing cells exhibiting positive staining for proliferating cell nuclear antigen as an indicator of ongoing growth factor activity localize preferentially in areas of microvascularization.³⁰ Hemosiderin deposits located near intimal microvessels, as demonstrated in the present study and as reported by others,²⁹ suggest the occurrence of prior hemorrhage. The newly formed vascular channels may themselves be prone to rupture or cause intraplaque hemorrhage after plaque fracture with subsequent in situ thrombosis, activating thrombin-mediated events. Thrombin and an as yet unidentified platelet-derived regulatory factor have been shown to be potent inducers of endothelin production.^{31 32} Endothelin-1 is a potent mitogen for vascular smooth muscle cells in vitro^{33 34} and induces the expression and release of several proto-oncogenes and growth factors, the latter of which may be synergistic.^{35 36 37} Indeed, endothelin-1 has recently been shown to promote neointimal formation in a rat model of balloon angioplasty.³⁸ The finding that tissue endothelin-1 immunoreactivity colocalizing with intimal smooth muscle cells was most abundant in hypercellular regions rich in microvessels suggests that the localization of endothelin-1 in the atherosclerotic plaque may reflect the site of atheroma progression of primary atherosclerotic lesions. In addition, plaque microvessels also provide a large surface area, which can promote further recruitment of mononuclear cells and thus contribute to the evolution of the atherosclerotic plaque by magnifying inflammatory responses.

The presence of endothelin-1–like immunoreactivity in the atherosclerotic plaque could reflect an internalization of endothelin-1 produced by endothelial cells³⁹ or the active production of endothelin-1 by intimal smooth muscle cells or macrophages.^{14 40} Previous experimental studies have demonstrated that oxidatively modified low-density lipoproteins activate human monocyte–derived macrophages to secrete immunoreactive endothelin-1 by activation of protein kinase C.^{14 41} Since oxidized low-density lipoproteins accumulate within the vessel wall, especially in areas of atheromatous gruel,⁴² the preferential colocalization of endothelin-1 immunoreactivity with macrophages surrounding atheromatous gruel supports the view of an increased de novo production of endothelin-1 within the atherosclerotic plaque rather than internalization of endothelin-1 produced by endothelial cells. Importantly, blood-derived monocytes did not stain for endothelin-1–like immunoreactivity (data not shown), indicating functional differences compared with macrophages residing in plaque.

Clinical Implications
The active coronary lesion is the pathological substrate of the clinical syndrome of unstable angina.¹ The culprit lesion in unstable angina exhibits a greater vasoconstrictor potential compared with a stable coronary artery lesion.^{8 43} Previous studies aimed at elucidating the pathophysiology underlying exaggerated vasoconstriction in unstable angina have focused mainly on impaired vasodilation due to endothelial dysfunction with loss or impaired diffusion of endothelium-derived relaxing factors through the altered vascular wall.⁴⁴ Endothelial injury has been shown to promote platelet-dependent vasoconstriction mediated by serotonin and thromboxane A₂ and thrombin-dependent vasoconstriction.⁴⁴ However, endothelial vasodilator dysfunction, manifested as paradoxical constriction to endothelium-dependent vasodilator agonists such as acetylcholine or serotonin, is present already in very early stages of atherosclerosis.^{45 46 47} Thus, although impaired endothelial vasodilator function undoubtedly predisposes for platelet- and thrombin-dependent vasoconstriction at the site of plaque disruption and thrombosis, these abnormalities of coronary vasomotor response, related simply to the presence of atherosclerotic plaques, are by themselves likely to play only a modulating rather than a major role in impairing coronary blood flow in unstable angina.⁴⁸ Indeed, we have previously shown that intracoronary thrombus formation is associated with only moderate degrees of vasoconstriction of human atherosclerotic coronary arteries in vivo and never caused occlusive spasm.⁴⁹ Similarly, ergometrine induced occlusive spasm at the site of preexisting stenoses in only 4% of patients with stable angina but in as many as 36% of patients with angina at rest.⁴³ These findings suggest that the coincidental presence of a local coronary artery hyperreactivity may be a crucial factor for the exaggerated constrictor responses observed in unstable angina. Importantly, previous studies have demonstrated that threshold concentrations of endothelin-1 sensitize the vasculature to a variety of vasoconstrictor stimuli, such as serotonin, norepinephrine, and angiotensin II.^{11 12 13} In addition, Lerman et al¹⁸ recently reported a close correlation between the degree of acetylcholine-induced coronary vasoconstriction and elevated plasma endothelin concentrations in parallel with enhanced endothelin immunoreactivity in the coronary vascular wall of hypercholesterolemic pigs. On the basis of these results, increases in local tissue concentrations of endothelin-1 could very likely be responsible for the segmental coronary hyperreactivity observed in unstable angina. Thus, endothelin-1 could not only enhance vascular tone by itself but also could amplify the contractions induced by other vasoconstrictors leading to arterial spasm upon stimulation.

Most importantly, the advent of endothelin receptor antagonists, which are currently in phase 1 clinical evaluation, offers a direct, novel therapeutic strategy and ultimately will define the precise role of this peptide in pathophysiological consequences of unstable angina.

In summary, the results of the present study demonstrate that the active coronary atherosclerotic lesion is characterized by an increase in tissue endothelin-1–like immunoreactivity. Endothelin-1 immunostaining localizes predominantly with plaque components indicative of chronic inflammatory processes. Despite potential sampling limitations,⁵⁰ the increased tissue endothelin-1 content may provide a clue to the mechanism of increased vasoreactivity of the culprit lesion in unstable angina, which is the clinical substrate of the active coronary atherosclerotic plaque.

Received November 8, 1994; accepted November 25, 1994.

	References

Top Abstract Introduction Methods Results Discussion References

 
1. Fuster V, Badimon L, Badimon JJ, Chesebro JH. Mechanisms of disease: the pathogenesis of coronary artery disease and the acute coronary syndromes (part one). N Engl J Med. 1992;326:242-250. [Medline] [Order article via Infotrieve]

2. Falk E. Unstable angina with fatal outcome: dynamic coronary thrombosis leading to infarction and/or sudden death. Circulation. 1985;71:699-708. [Abstract/Free Full Text]

3. Richardson PD, Davies MJ, Born GV. Influence of plaque configuration and stress distribution on fissuring of coronary atherosclerotic plaque. Lancet. 1989;2:941-944. [Medline] [Order article via Infotrieve]

4. van der Wal AC, Becker AE, van der Loos CM, Das PK. Site of intimal rupture or erosion of thrombosed coronary atherosclerotic plaques is characterized by an inflammatory process irrespective of the dominant plaque morphology. Circulation. 1994;89:36-44. [Abstract/Free Full Text]

5. Moreno PR, Falk E, Palacios IF, Newell JB, Fuster V, Fallon JT. Macrophage infiltration in acute coronary syndromes: implications for plaque rupture. Circulation. 1994;90:775-778. [Abstract/Free Full Text]

6. Fuster V, Badimon L, Badimon JJ, Chesebro JH. Mechanisms of disease: the pathogenesis of coronary artery disease and the acute coronary syndromes (part two). N Engl J Med. 1992;326:310-318. [Medline] [Order article via Infotrieve]

7. Willerson JT, Golino P, Eidt J, Campbell WB, Buja LM. Specific platelet mediators and unstable coronary artery lesions: experimental evidence and potential clinical implications. Circulation. 1989;80:198-205. [Abstract/Free Full Text]

8. Bogarty P, Hackett D, Davies G, Maseri A. Vasoreactivity of the culprit lesion in unstable angina. Circulation. 1994;90:5-11. [Abstract/Free Full Text]

9. Yangiasawa M, Kurihara H, Kimura S, Tomobe Y, Kobayashi M, Mitsui Y, Yazaki Y, Goto K, Masaki T. A novel potent vasoconstrictor peptide produced by vascular endothelial cells. Nature. 1988;332:411-415. [Medline] [Order article via Infotrieve]

10. Inoue A, Yangiasawa M, Kimura S, Kasuya Y, Niyauchi T, Goto K, Masaki T. The human endothelin family: three structurally and pharmacologically distinct isopeptides predicted by three separate genes. Proc Natl Acad Sci U S A. 1989; 86:2863-2867.

11. Yang Z, Richard D, Von Segesser L, Bauer E, Stulz P, Turina M, Lüscher TF. Threshold concentrations of endothelin-1 potentiate contractions to norepinephrine and serotonin in human arteries: a new mechanism of vasospasm? Circulation. 1990;82:188-195. [Abstract/Free Full Text]

12. Tabuchi Y, Nakamura M, Rakugi H, Nagano M, Ogihara T. Endothelin enhances adrenergic vasoconstriction in perfused rat mesenteric arteries. Biochem Biophys Res Commun. 1989; 159:1304-1308.

13. Dohi Y, Hahn AWA, Boulanger CM, Bühler FR, Lüscher TF. Endothelin stimulated by angiotensin II augments contractility of spontaneously hypertensive rat resistance arteries. Hypertension. 1992;19:131-137. [Abstract/Free Full Text]

14. Ehrenreich H, Andreson RW, Fox CH, Rieckmann P, Hoffman GS, Travis WD, Coligan JE, Kehrl JH, Fauci AS. Endothelins, peptides with potent vasoactive properties, are produced by human macrophages. J Exp Med. 1990;172:1741-1748. [Abstract/Free Full Text]

15. Sessa WC, Kaw S, Hecker M, Vane JR. The biosynthesis of endothelin-1 by human polymorphonuclear leukocytes. Biochem Biophys Res Commun. 1991;174:613-615. [Medline] [Order article via Infotrieve]

16. Hinohara T, Selmon MR, Robertson GC, Braden L, Simpson JB. Directional atherectomy: new approaches for treatment of obstructive coronary and peripheral vascular disease. Circulation. 1990;81(suppl IV):IV-79-IV-91.

17. Lerman A, Edwards BS, Hallett JW, Heublein DM, Sandberg SM, Burnett JC Jr. Circulating and tissue endothelin immunoreactivity in advanced atherosclerosis. N Engl J Med. 1991;325:997-1001. [Abstract]

18. Lerman A, Webster MWI, Chesebro JH, Edwards WD, Wei C-M, Fuster V, Burnett JC. Circulating and tissue endothelin immunoreactivity in hypercholesterolemic pigs. Circulation. 1993;88:2923-2928. [Abstract/Free Full Text]

19. Cordell JL, Falini B, Erber WN, Ghosh AK, Abdulaziz Z, MacDonald S, Pulford KA, Stein H, Mason DY. Immunoenzymatic labelling of monoclonal antibodies using immune complexes of alkaline phosphatase and monoclonal anti-alkaline phosphatase (APAAP complexes). J Histochem Cytochem. 1984;32:219-229. [Abstract]

20. Hollander M, Wolfe DA. Nonparametric Statistical Methods. New York, NY: John Wiley; 1973:198.

21. Murch SH, Braegger CP, Sessa WC, MacDonald TT. High endothelin-1 immunoreactivity in Crohn's disease and ulcerative colitis. Lancet. 1992;339:381-385. [Medline] [Order article via Infotrieve]

22. Munro JM, Cotran RS. The pathogenesis of atherosclerosis: atherogenesis and inflammation. Lab Invest. 1988;58:249-261. [Medline] [Order article via Infotrieve]

23. Alexander RW. Inflammation and coronary artery disease. N Engl J Med. 1994;331:468-469. Editorial. [Free Full Text]

24. Ross R. The pathogenesis of atherosclerosis: a perspective for the 1990s. Nature. 1993;362:801-809. [Medline] [Order article via Infotrieve]

25. Winkles JA, Alberts GF, Brogi E, Libby P. Endothelin-1 and endothelin receptor mRNA expression in normal and atherosclerotic human arteries. Biochem Biophys Res Commun. 1993;191: 1081-1088.

26. Mitchinson MJ, Ball RY. Macrophages and atherogenesis. Lancet. 1987;2:146-148. [Medline] [Order article via Infotrieve]

27. Steinberg D. Antioxidants and atherosclerosis. Circulation. 1991;84:1420-1425. [Free Full Text]

28. Barger AC, Beeuwwkes R, Lainey LL, Siverman KJ. Hypothesis: vasa vasorum and neovascularization of human coronary arteries. N Engl J Med. 1984;310:175-177. [Medline] [Order article via Infotrieve]

29. Imparato AM, Riles TS, Mintzer R, Baumann FG. The importance of hemorrhage in the relationship between gross morphologic characteristics and cerebral symptoms in 376 carotid artery plaques. Ann Surg. 1982;197:195-203.

30. Brogi E, Winkles JA, Underwood R, Clinton SK, Alberts GF, Libby P. Distinct patterns of expression of fibroblast growth factors and their receptors in human atheroma and nonatherosclerotic arteries. Association of acidic FGF with plaque microvessels and macrophages. J Clin Invest. 1993;92:2408-2418.

31. Boulanger CM, Tanner FC, Bea ML, Hahn AWA, Werner A, Lüscher T. Oxidized low density lipoproteins induce mRNA expression and release of endothelin from human and porcine endothelium. Circ Res. 1992;70:1191-1197. [Abstract/Free Full Text]

32. Ohlstein EH, Storer JA, Debouck C, Feuerstein G. Platelets stimulate expression of endothelin mRNA and endothelin biosynthesis in cultured endothelial cells. Circ Res. 1991;69:832-841. [Abstract/Free Full Text]

33. Miller WL, Redfield MM, Burnett JC Jr. Integrated cardiac, renal, and endocrine actions of endothelin. J Clin Invest. 1989;83:317-320.

34. Dubin D, Pratt RE, Cooke JP, Dzau VJ. Endothelin, a potent vasoconstrictor, is a vascular smooth muscle mitogen. J Vasc Med Biol. 1989;1:150-154.

35. Komura I, Kurihara H, Sugiyama T, Takafu F, Yazaki Y. Endothelin stimulates c-fos and c-myc expression and proliferation of vascular smooth muscle cells. FEBS Lett. 1988;238:249-252. [Medline] [Order article via Infotrieve]

36. Bobik A, Grooms A, Millar JA, Mitchell A, Grinpukel S. Growth factor activity of endothelin on vascular smooth muscle. Am J Physiol. 1990;258:C408-C415. [Abstract/Free Full Text]

37. Scott-Burden T, Resink TJ, Hahn AWA, Vanhoutte PM. 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-S100.

38. Douglas SA, Louden C, Vickery-Clark LM, Storer BL, Hart T, Feuerstein GZ, Elliott JD, Ohlstein EH. A role for endogenous endothelin-1 in neointimal formation after rat carotid artery balloon angioplasty. Circ Res. 1994;75:190-197. [Abstract/Free Full Text]

39. Resink TJ, Scott-Burden T, Boulanger C, Weber E, Bühler FR. Internalization of endothelin by cultured human vascular smooth muscle cells: characterization and physiological significance. Mol Pharmacol. 1990;38:244-252. [Abstract]

40. Resink TJ, Hahn AWA, Scott-Burden T, Powell J, Weber E, Bühler FR. Inducible endothelin mRNA expression and peptide secretion in cultured human vascular smooth muscle cells. Biochem Biophys Res Commun. 1990;168:1303-1310. [Medline] [Order article via Infotrieve]

41. Martin-Nizard F, Houssaini HS, Lestavel-Delattre S, Duriez P, Fruchart J-C. Modified low density lipoproteins activate human macrophages to secrete immunoreactive endothelin. FEBS Lett. 1991;293:127-130. [Medline] [Order article via Infotrieve]

42. Ylä-Herttuala S, Palinski W, Rosenfeld ME, Parthasarathy C, Carew TE, Butler S, Witzum JL, Steinberg D. Evidence for the presence of oxidatively modified low density lipoprotein in atherosclerotic lesions of rabbit and man. J Clin Invest. 1989;84:1086-1095.

43. Bertrand ME, La Blanche JM, Tilmant PY, Thieuleux FA, Delfarge MR, Carre G, Asseman P, Berzin B, Libersa C, Laurent JM. Frequency of provoked coronary arterial spasm in 1089 consecutive patients undergoing coronary arteriography. Circulation. 1982;65:1299-1306. [Abstract/Free Full Text]

44. Vanhoutte PM, Shimokawa H. Endothelium-derived relaxing factor and coronary vasospasm. Circulation. 1989;80:1-9. [Abstract/Free Full Text]

45. Vita JA, Treasure CB, Nabel EG, McLenachan JM, Fish RD, Yeung AC, Vekshtein VI, Selwyn AP, Ganz P. Coronary vasomotor response to acetylcholine relates to risk factors for coronary artery disease. Circulation. 1990;81:491-497. [Abstract/Free Full Text]

46. Zeiher AM, Drexler H, Wollschläger H, Just H. Modulation of coronary vasomotor tone: progressive endothelial dysfunction with different early stages of coronary atherosclerosis. Circulation. 1991;83:391-401. [Abstract/Free Full Text]

47. McFadden EP, Clarke JG, Davies GJ, Kaski JC, Haider AW, Maseri A. Effect of intracoronary serotonin on coronary vessels in patients with stable angina and patients with variant angina. N Engl J Med. 1991;324:648-654. [Abstract]

48. Maseri A, Davies G, Hackett D, Kaski JC. Coronary artery spasm and vasoconstriction: the case for a distinction. Circulation. 1990;81:1983-1991. [Free Full Text]

49. Zeiher AM, Schächinger V, Weitzel SH, Wollschläger H, Just H. Intracoronary thrombus formation causes focal vasoconstriction of epicardial arteries in patients with coronary artery disease. Circulation. 1991;83:1519-1525. [Abstract/Free Full Text]

50. Waller BF, Pinkerton CA. `Cutters, scoopers, hovers and scrappers': the importance of atherectomy devices and clinical relevance of tissue removed. J Am Coll Cardiol. 1990;15:426-428.[Medline] [Order article via Infotrieve]

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				C. Ferri, G. Properzi, G. Tomassoni, A. Santucci, G. Desideri, A. E. Giuliani, R. C. Starling, N. B. Ratliff, D. J. Cook, P. McCarthy, et al. Patterns of Myocardial Endothelin-1 Expression and Outcome After Cardiac Transplantation Circulation, April 16, 2002; 105(15): 1768 - 1771. [Abstract] [Full Text] [PDF]

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