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Eur J Cardiothorac Surg 1998;14:367-372
© 1998 Elsevier Science NL

Increased tissue endothelin-1-like immunoreactivity in the internal mammary artery of patients with diabetes or hypercholesterolemia modulates the graft flow in the peri-operative period

Heike Göbela, Christian Ihlinga, Janine Dentzc, Hans E. Schaefera, Andreas M. Zeiherb, Gustav Fraedrichc

a Department of Pathology, University Hospital, Freiburg, Germany
b Department of Internal Medicine IV, University Hospital, Frankfurt, Germany
c Department of Vascular Surgery, University Hospital, Anichstrasse 35, A-6020 Innsbruck, Austria

Received 3 June 1998; accepted 3 June 1998.

Corresponding author. Tel.: +43 512 5042587; fax: +43 512 5042559; e-mail: Gustav.Fraedrich@uibk.ac.at


   Abstract
Top
 Abstract
Introduction
Material and methods
 Results
 Discussion
References
 
Objective: Peri-operative ischemic episodes following coronary artery bypass grafting with the internal mammary artery (IMA) are thought to be due to a vasospasm of this conduit. Endothelin-1 (ET-1) is a potent vasoconstrictor by itself and increases the response to other vasoconstrictor stimuli. This study focused on the possible role of an enhanced tissue ET-1-like immunoreactivity in the peri-operative reaction of the IMA in patients with diabetes or hypercholesterolemia. Methods: Specimens of the distal part of the IMA from 46 patients (mean age 58.5 years, four women, 42 men) were studied prospectively. Nine of those patients were diabetic and 26 had evidence of hypercholesterolemia. Another cohort of 20 IMA specimens was stained retrospectively; 10 of those biopsies were from patients that had experienced transient ischemic events peri-operatively in the myocardial area supplied by the IMA. The biopsies were examined histologically and immunohistochemically (rabbit polyclonal ET-1 antiserum, three-step avidin-biotin complex) with regard to their immunoreactivity to tissue ET-1. Results: An immunoreactivity to ET-1 (graded 0–3) was present in 89% of the biopsies. The reactivity was significantly higher in patients with hypercholesterolemia (1.92±0.74) when compared to controls (1.0±0.63) (P=0.04). The reactivity was also increased in patients with non-insulin-dependent diabetes mellitus (2.1±0.79), when compared to controls (P=0.02). Mostly transient ischemic events in the area supplied by the IMA seemed to occur more frequently when the biopsies revealed a higher immunoreactivity to ET-1. They showed an increased reactivity to ET-1 (2.27±0.76) compared to 10 patients with an uneventful peri-operative course (1.66±0.71) (P=0.04). Conclusions: This study provides evidence that the internal mammary artery is not a passive conduit. Vasospasm or vasoconstriction, in particular at its distal end, may occur more frequently in patients with hypercholesterolemia or diabetes, and may lead to post-operative ischemic events.

Key Words: Internal mammary artery • Vasospasm • Endothelin-1 • Diabetes mellitus • Hypercholesterolemia


   Introduction
Top
 Abstract
 Introduction
Material and methods
 Results
 Discussion
References
 
For over a decade the survival benefit of the use of the left internal mammary artery (IMA) for patients undergoing coronary revascularization has been well established. Therefore, in particular in the more recent period, an expanded use of the IMA in coronary artery bypass grafting (CABG) has been reported [1] [2]. Although the IMA provides a superior long term patency, its flow seems to be limited in situations of large regional myocardial flow demand or when undisturbed oxygen supply is warranted especially in the very early post-operative period [3] [4].

The incidence of this so-called IMA malperfusion syndrome has been reported to amount to 2% after primary CABG and to 20% after reoperations. It is associated with an increased myocardial infarction rate and lethality [5] [6]. In most cases, the cause of such malperfusion may be due to technical or sizing problems. A mismatch between a small, or spastic, IMA at its distal part and the target artery [7] may result in hypoperfusion in conditions of a large myocardial flow demand. In addition, the vasoconstrictive effect of several drugs e.g. peri-operatively administrated inotropic substances and potassium, is increasingly accepted [8]. From a physiological aspect, an inferior flow capacity of the IMA may result from the reduced pressure in this vessel during diastole when coronary blood flow should be maximal [9].

In addition, there is increasing evidence for the influence of cardiovascular risk factors on survival after CABG e.g. the adverse effect of diabetes on the survival of the patients cannot be reduced by IMA grafts [10]. Moreover, low density lipoproteins and hypercholesterolemia have been shown to considerably attenuate endothelium-dependent vasodilatation [11]. In hypertensive patients, the modulation of the endothelin-1 (ET-1) gene expression in smooth muscle cells seems to affect the proliferative activity of the endothelium [12]. In order to clarify these findings, we performed a study focusing on the role of ET-1 in the internal mammary artery. ET-1 is a very potent vasoconstrictor peptide, which was originally reported to be produced by endothelial cells [13]. In addition to its long-lasting vasoconstrictive properties [13], ET-1 substantially potentiates the constrictor effects of other vasoconstrictor stimuli [14]. Moreover, recently it has been shown that atherosclerotic plaques from patients with acute coronary syndromes (rest angina, crescendo angina and post-infarction angina) contain a significantly greater amount of locally produced ET-1 than plaques from patients with stable angina, providing evidence that regional increases of ET-1 concentrations may be responsible for the segmental coronary hyper-reactivity underlying the acute coronary syndromes [15] [16] [17] [18]. Furthermore, ET-1 has mitogenic properties for vascular smooth muscle cells in vitro, suggesting that it has a role as growth factor [19]. Interestingly, ET-1 gene expression as well as ET-1 secretion of endothelial cells has been shown to be induced by insulin and glucose [20] [21] [22]. Furthermore, a recent study provided evidence for enhanced tissue ET-1-like immunoreactivity (ET-1-IR) in the coronary vascular wall of pigs after a 4 months hypercholesterolemic diet [23]. Likewise, ET-1 levels might be increased in segments of the IMA from patients with diabetes mellitus or hypercholesterolemia and locally augmented ET-1 levels in both conditions may contribute to the occurrence of peri-operative vasospasm.

In order to establish a possible role for ET-1 in the peri-operative vasospastic reaction of the IMA, we prospectively studied the extent of ET-1-IR in segments of the IMA from patients with non-insulin-dependent diabetes mellitus (NIDDM) and hypercholesterolemia undergoing CABG, as well as from a control group. Based on the results of this study, we retrospectively conducted a second investigation to assess the extent of ET-1-IR in segments of the IMA from patients undergoing CABG with peri-operative transient ischemic events and from a control group.


   Material and methods
Top
 Abstract
 Introduction
Material and methods
Results
 Discussion
References
 
Patients
Specimens of the distal part of the IMA from 46 patients undergoing coronary artery bypass surgery for severe coronary artery disease (mean age 58.5 years, four women, 42 men) were studied prospectively. Preparation of the IMA was performed using the conventional pedicle technique, the wide musculofascial pedicle was covered with a sponge soaked with papaverine-saline solution. The patients were divided into three groups: (1) patients with a history of NIDDM requiring therapy with oral agents, (2) patients with elevated serum cholesterol levels (defined as 75th percentile adjusted for age and sex) and (3) a control group with neither diabetes mellitus nor hypercholesterolemia (hypercholesterolemia was excluded with serum cholesterol levels <220 mg/dl, LDL cholesterol <140 mg/dl or LDL:HDL ratio <3.7). The demographic and clinical data for both groups are listed in Table 1. The patients were matched as to medication with ACE-inhibitors and Ca-antagonists.


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  		Table 1. Demographic data (n=46)

 
Based on the results of this first study, we performed a further retrospective investigation using IMA specimens from 10 patients with peri-operative transient ischemic events in the myocardial area supplied by the IMA, as verified by ECG changes and/or elevation of cardiac enzymes as mentioned below and a control group of 10 patients with uneventful peri-operative course. These specimens had been preserved from a former histological study on 150 patients.

Tissue preparation
All tissue specimens retrieved were immediately fixed in 4% unbuffered formalin. The tissue was then prepared according to standard methods, and embedded in paraffin. Serial sections were stained for hematoxylin/eosin and elastica van Gieson.

Immunohistochemistry
Immunostaining was performed using a modified three step avidin-biotin complex method [24] [25]. In short, the sequence of reagent application was as follows: first, the rabbit polyclonal ET-1 antiserum diluted 1:250 (Peninsula, Belmont, CA, IHC 6901) was applied to the sections. After washing, the sections were subsequently incubated with a biotinylated secondary antibody followed by the incubation with the preformed avidin-biotin peroxidase complex (Vector Lab. Burlingame USA). Peroxidase activity was visualized by 3-amino-9-ethylcarbazole (Sigma A 5754; 25) to yield a brown reaction product. Sections were slightly counterstained with hematoxylin. Control experiments were performed by staining samples of the internal mammary artery both with a well known ET-1 reactivity seen in the endothelium (positive control) and by substituting the polyclonal anti ET-1 serum with non-immune rabbit serum (Dako X 90210, negative control). The positive controls were invariably positive and the negative controls were invariably negative. The specificity of the rabbit polyclonal anti-ET-1 antiserum has been validated previously [15]. The antiserum showed a cross reactivity with human big endothelin of 17%, with endothelin-2 of 7% and with endothelin-3 of 7% according to the manufacturer.

Histochemical and immunohistochemical analysis
The light microscopical sections were examined for the localization of ET-1-IR. Comparative examination of serial sections permitted the assessment of colocalization of ET-1-IR with myofibroblasts (actin positive). ET-1-immunostaining intensity in the media was graded semi-quantitatively from 0 to 3: grade 0 indicated the absence of any staining, grade 1 indicated positivity associated with less than 10% of the cells ( Fig. 1 A); grade 2 indicated positivity of 10–30% of the cells ( Fig. 1B); and grade 3 indicated positivity of 30–60% of the cells ( Fig. 1C). The grading was independently performed by two of the investigators, without knowledge of clinical information. The grades independently assigned by both observers agreed within one grade, differences were resolved by joint examination.



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  		Fig. 1. Arrows show whenever preserved endothelial cells showed a strong endothelin-1-like immunoreactivity. Endothelin-1-like immunostaining intensity in the media of internal mammary artery segments (brown reaction product). (A) grade 1: weak endothelin-1 positivity in less than 10% of the cells. (B) grade 2: endothelin-1 positivity in 10–30% of the cells. (C) endothelin-1 positivity in more than 30% of the cells. (original magnificationx300).

 
Statistical analysis
The results of the grading of ET-1 staining are expressed as mean±1 SD. Statistical comparisons were made by analysis of variance followed by the Student–Newman–Keul test.


   Results
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 Abstract
 Introduction
Material and methods
 Results
Discussion
References
 
Histology and immunohistology
A normal vessel wall of the internal mammary artery by histological criteria was present in 4/11 (36%) specimens of the control group, in 3/9 (33%) specimens from diabetic patients and in 11/26 (42%) specimens from hypercholesterolemic patients, whereas focal intimal cushion-like hyperplasia or diffuse hyperplasia was present in 7/11 (64%) patients of the control group, in 6/9 (67%) of diabetic patients (67%) and in 15/26 (58%) patients with hypercholesterolemia. The endothelium was sometimes incompletely preserved probably due to peri-operative manipulation but, whenever present, endothelial cells showed a strong ET-1-IR ( Fig. 1). The cytoplasma of medial smooth muscle cells showed an inconsistent ET-1-IR ( Fig. 1), whereas myofibroblasts of focal neointimal hyperplasia demonstrated a strong ET-1-IR in all 28 cases with intimal hyperplasia. Although ET-1-IR in the media was present in 41/46 specimens (89%), the grade of the immunostaining was significantly higher in patients with diabetes mellitus (2.1±0.79; P=0.02 vs. control) and hypercholesterolemia (1.92±0.74; P=0.04 vs. control) compared to the control group (1.0±0.63, Table 2).


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  		Table 2. ET-1 immunoreactivity in patients with diabetes or hypercholesterolemia (n=46)

 
Clinical course
In this first study transient ischemic events in the area supplied by the IMA seemed to occur more frequently in patients with higher ET-1 staining grades.

In order to clarify this, we retrospectively investigated another 20 IMA specimens. Although there were no cases with an IMA malperfusion syndrome requiring therapy in this cohort, 10 of the patients had experienced post-operative transient ischemic events, verified by ECG changes and elevation of cardiac enzymes: in seven patients transient ST segment elevation or depression >0.1 mV occurred in the area supplied by the IMA graft, in three cases prolonged ST segment changes were observed, and a CK-MB:CK ratio of >10% was observed in six of these patients. Another group of 10 patients without any post-operative event served as control.

In this study cohort, patients with peri-operative ischemic events in the area supplied by the grafted IMA showed a significantly increased ET-1-IR (2.27±0.76) in comparison to 10 patients with an uneventful peri-operative course (1.66±0.71; P=0.04 vs. control) (Table 3).


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  		Table 3. ET-1 immunoreactivity in patients with ischemic events (n=20):

 

   Discussion
Top
 Abstract
 Introduction
Material and methods
 Results
 Discussion
References
 
The results of the present study demonstrate the presence of a significantly increased ET-1-IR in the wall of the internal mammary artery of patients with NIDDM and hypercholesterolemia undergoing CABG. More importantly, patients with transient peri-operative ischemic events in the myocardial area supplied by the IMA exhibited significantly greater ET-1-IR in specimens from the distal part of the bypass vessel compared to specimens from a control group with an uneventful peri-operative course. Taken together, these findings raise the possibility of a role for ET-1 in the pathophysiological processes associated with vasospastic reactions of the IMA complicating the peri-operative course after coronary artery bypass grafting from patients with NIDDM and hypercholesterolemia.

The vasoconstrictory effects of ET-1 are mediated through activation of the ETA receptor which is mainly present on medial smooth muscle cells. Since it had been shown [26] that receptor densities for ETA receptors in the media of diseased and normal coronary arteries were similar, whereas they were lacking in intimal smooth muscle cells of atherosclerotic plaque tissue, the response of medial smooth muscle cells to ET-1 might not be blunted. In addition, it has been shown that threshold concentrations of ET-1 potentiate the response to other vasoconstrictors. Therefore, the response of medial smooth muscle cells with a high content of ET-1 to other endogenous vasoconstrictors would be potentiated and may lead to vasospasm [14].

Hyperinsulinemia is a separate risk factor for accelerated vascular disease associated with diabetes mellitus [27] [28]. In addition to the effects of insulin upon ET-1 gene expression and ET-1 secretion, insulin increases the number of ET-1 receptors and, hence, stimulates the action of ET-1 on cultured vascular smooth muscle cells [29].

Hypercholesterolemia exerts profound effects on coronary vasodilator function [30] [31] [32] and is associated with an increased sensitivity to vasoconstrictors like catecholamines and serotonin [33]. In addition, a recent study demonstrated that coronary vasoconstriction in response to acetycholine was closely correlated with an increase in plasma ET-1 levels in hypercholestrolemic pigs, which at the same time showed an enhanced ET-1-IR in the coronary wall [23]. Thus, increased ET-1 levels in the vascular wall of patients with NIDDM and hypercholesterolemia might contribute to vasospastic reactions. Recent publications showed a close interaction of ACE inhibitors with plasma endothelin in vivo [34], in the present study, there was no obvious correlation between ACE inhibitor medication and the reactivity to ET-1.

ET-1 is a smooth muscle mitogen and not only stimulates the synthesis mRNA from the proto-oncogenes c-myc and c-fos but also that of DNA in cultured rat aortic cells [35] [36]. Moreover, insulin potentiates the proliferation of vascular smooth muscle cells induced by ET-1 leading to a 10-fold increase in DNA synthesis [29]. Since proliferation of myofibroblasts with their ability to synthesize connective tissue matrix is an important event in the development of the atherosclerotic process [37], ET-1 may contribute to the development of atherosclerosis in hyperinsulinemic as well as hypercholesterolemic states.

Regardless of whether the tissue ET-1 immunoreactivity is due to an internalization of ET-1 produced by endothelial cells or due to de novo production by other cells of the vascular wall, the increased ET-1 levels observed in the vascular wall of hyperglycemic and hypercholesterolemic patients provides evidence in support of a role for ET-1, not only as a mitogen itself, but also as a mediator in the atherogenic process associated with NIDDM and hypercholesterolemia.

In the present study, ET-1-IR was significantly increased in both normal segments of the internal mammary artery as well as in segments with neointimal hyperplasia of patients with NIDDM and hypercholesterolemia compared to the control group. Thus, the increase of ET-1 in the vascular wall of patients with NIDDM and hypercholesterolemia does not appear to be related to the presence of atherosclerotic lesions. Although ET-1 immunostaining can only be graded semi-quantitatively, the differences between patients with NIDDM and hypercholesterolemia and the control group were striking in the present study. Nevertheless, minor degrees of ET-1-IR were also detected in the medial smooth muscle layer in the majority of internal mammary artery specimens from the control group. However, it should be kept in mind that the specimens were obtained from patients with severe coronary atherosclerosis requiring CABG. Thus, other factors than NIDDM or hypercholesterolemia might also be involved in the expression of ET-1 in the muscular layer of histologically normal arteries of patients with severe coronary atherosclerosis.

In summary, the present study provides evidence that the internal mammary artery is not a passive conduit. Vasospasms or vasoconstriction occurring, in particular, at its distal end, may lead to regional myocardial ischemia and functional impairment in situations with large myocardial oxygen demand. In addition, the increased local tissue ET-1 levels in the wall of the IMA from patients with NIDDM and hypercholesterolemia undergoing CABG might contribute to the release of peri-operative vasospasm leading to transient peri-operative ischemic events in the myocardial area supplied by the IMA.


   References
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 Abstract
 Introduction
Material and methods
 Results
 Discussion
References
 

  1. Barner H.B. Use of the internal thoracic artery: simple, complex, or with a backup?. Ann Thorac Surg 1994;57:8-9.[Medline]
  2. Loop F.D., Lytle B.W., Cosgrove D.M., Stewart R.W., Goormastic M., Williams G.W., Golding L.A., Gill C.C., Taylor P.C., Sheldon W.C., Proudfit W.L. Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events. N Engl J Med 1986;314:6.
  3. Friesewinkel O., Harris L.J., Crooke G.A., LaMendola C.L., Grossi E.A., Baumann F.G., Esposito R.A. Effects of graded reductions in internal mammary bypass flow on left ventricular function. Ann Thorac Surg 1993;56:1348-1350.[Abstract]
  4. Kawsuji M., Tsujiguchi H., Tedorya T., Taki J., Iwa T. Evaluation of postoperative flow capacity of internal mammary artery. J Thorac Cardiovasc Surg 1990;99:696-702.[Abstract]
  5. Carrel T., Kujawski T., Zünd G., Schwitter J., Amann F.W., Gallino A., Bertel O., Jenni R., Turina M. The internal mammary artery malperfusion syndrome: incidence treatment and angiographic verification. Eur J Cardio-thorac Surg 1995;9:190-197.[Abstract]
  6. Navia D., Cosgrove D.M., Lytle B.W., et al. Is the internal thoracic artery the conduit of choice to replace a stentic vein graft?. Ann Thorac Surg 1994;57:40-44.[Abstract]
  7. Nataf P., Hadjiisky P., Bourbon A., Peuchmaurd M., Leprince P., Regan M., Escolano S., Gandjbakch I. Morphometric and metabolic profile of the distal segment of the internal mammary artery: caution on its use for coronary anastomoses. Eur J Cardio-thorac Surg 1996;10:965-970.[Abstract]
  8. He G.W., Acuff T.E., Yang C.Q., Ryan W.H., Mack M.J. Middle and proximal sections of human internal mammary artery are not `passive conduits'. J Thorac Cardiovasc Surg 1993;106:106.
  9. Tedoriya T., Kawasuji M., Sakakibara N., Ueyama K., Watanabe Y. Pressure characteristics in arterial grafts for coronary bypass surgery. Cardiovasc Surg 1995;3:381-385.[Medline]
  10. Morris JJ, Smith LR, Jones RH, Glower DD, Morris PB, Muhlbaier LH, Reves JG, Rankin JS. Influence of diabetes and mammary artery grafting on survival after coronary bypass. Circulation 1991;84:III275–III284.
  11. Lüscher TF, Tanner FC. Endothelial regulation of vascular tone and growth. Am J Hypertension 1993;6:283S–293S.
  12. Hasegawa K., Fujiwara H., Doyama K., Inada T., Ohtani S., Fujiwara T., Hosoda K., Nakao K., Sasayama S. ET-1 selective receptor in the arterial intima of patients with hypertension. Hypertension 1994;23:288-293.[Abstract/Free Full Text]
  13. Yanigasawa 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]
  14. Yang Z., Richard D., von Segesser L., Bauer E., Stulz P., Turina M., Lüscher T.F. 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]
  15. Ihling C., Göbel H.R., Lippoldt A., Wessels S., Paul M., Schaefer H.E., Zeiher A.M. Endothelin-1-like immunoreactivity in human atherosclerotic coronary tissue: a detailed analysis of the cellular distribution of endothelin-1. J Pathol 1996;179:303-308.[Medline]
  16. Lerman A., Edwards B.S., Halett J.W., Heublein D.M., Sandberg S.M., Burnett J.C. Circulating and tissue endothelin immunoreactivity in advanced atherosclerosis. N Engl J Med 1991;325:997-1001.[Abstract]
  17. Zeiher A.M., Ihling C., Pistorius K., Schächinger V., Schaefer H.E. Increased tissue endothelin immunoreactivity in atherosclerotic lesions associated with acute coronary syndromes. Lancet 1994;344:1405-1406.[Medline]
  18. Zeiher A.M., Goebel H.R., Schächinger V., Ihling C. 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. Circulation 1995;91:941-947.[Abstract/Free Full Text]
  19. Dubin D., Pratt R.E., Cooke J.E., Dzau V.J. Endothelin, a potent vasoconstrictor, is a vascular smooth muscle mitogen. J Vasc Med Biol 1989;1:150-154.
  20. Hu R.M., Levin E.R., Pedram A., Frank H.J.L. Insulin stimulates production and secretion of endothelin from bovine endothelial cells. Diabetes 1993;42:351-358.[Abstract]
  21. Oliver F.J., de la Rubia G., Feener E.P., Lee M.E., Loeken M.R., Shiba T., Quertermous T., King G.L. Stimulation of endothelin-1 expression by insulin in endothelial cells. J Biol Chem 1991;266:23251-23256.[Abstract/Free Full Text]
  22. Yamauchi T., Ohnaka K., Takayanagi R., Umeda F., Nawata H. Enhanced secretion of endothelin-1 by elevated glucose levels from cultured bovine endothelial aortic cells. FEBS Letters 1990;267:16-18.[Medline]
  23. Lerman A., Webster M.W.I., Chesebro J.H., Edwards W.D., Wie C.M., Fuster V., Burnett J.C. Circulating and tissue endothelin immunoreactivity in hypercholesterolemic pigs. Circulation 1993;88:2923-2928.[Abstract/Free Full Text]
  24. Hsu S.M., Raine L., Fanger H. Use of avidin-biotin-peroxidase complex (ABC) in immunoperoxidase techniques: a comparison between ABC and unlabeled antibody (PAP) procedures. J Histochem Cytochem 1981;29:577-580.[Abstract]
  25. Schaefer HE. Methoden zur histologischen, zytologischen und zytochemischen Diagnostik von Blut und Knochenmark. In: Remmele W, ed. Pathologie Vol 1. Berlin, Heidelberg, New York, Tokyo: Springer, 1984;435–452.
  26. Bacon C.R., Cary N.R.B., Davenport A.P. Endothelin peptide and receptors in human atherosclerotic coronary artery and aorta. Circ Res 1996;79:794-801.[Abstract/Free Full Text]
  27. Gordon T., Castelli W.P., Hjortland M.C., Kannel W.B., Dawber T.R. Diabetes, blood lipids and the role of obesity in coronary heart disease risks for women. The Framingham Study. Ann Intern Med 1977;87:393-397.
  28. Stout R.W. Diabetes and atherosclerosis-the role of insulin. Diabetologia 1979;16:141-150.[Medline]
  29. Frank H.J.L., Levin E.R., Hu R.M., Pedram A. Insulin stimulates endothelin binding and action on cultured vascular smooth muscle cells. Endocrinology 1993;133:1092-1097.[Abstract]
  30. Vita J.A., Treasure C.B., Nabel E.G., McLenachan J.M., Fish R.D., Yeung A.C., Vekshtein V.I., Selwyn A.P., Ganz P. Coronary vasomotor response to acetylcholine relates to risk factors for coronary artery disease. Circulation 1990;81:491-497.[Abstract/Free Full Text]
  31. Zeiher A.M., Drexler H., Saurbier H.B., Just H. Endothelium-mediated coronary blood flow modulations in humans. Effects of age, atherosclerosis, hypercholesterolemia, and hypertension. J Clin Invest 1993;92:652-662.
  32. Zeiher A.M., 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]
  33. Heistad D.D., Armstrong M.L., Marcus M.L., Piegors D.J., Mark A.L. Augmented responses to vasoconstrictor stimuli in hypercholesterinemic and atherosclerotic monkeys. Circ Res 1984;54:711-718.[Abstract/Free Full Text]
  34. Hirata Y., Takagi Y., Fukuda Y., Marumo F. Endothelin is a potent mitogen for rat vascular smooth muscle cells. Atherosclerosis 1989;78:225-228.[Medline]
  35. Galatius-Jensen S., Wroblewski H., Emmeluth C., Bie P., Haunso S., Kastrup J. Plasma endothelin in congestive heart failure: effect of the ACE inhibitor fosinopril. Cardiovasc Res 1996;32:1148-1154.[Abstract/Free Full Text]
  36. Komuro I., Kurihara I., Sugiyama T., Takaku F., Yazaki Y. Endothelin stimulates c-fos and c-myc expression and proliferation of vascular smooth muscle cells. FEBS Letters 1988;238:249-252.[Medline]
  37. Ross R. The pathogenesis of atherosclerosis – an update. N Engl J Med 1986;314:488-500.[Medline]




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