Zusammenfassung
Das Endothel als innere Auskleidung aller Blutgefäße hat eine zentrale Bedeutung in der Homöostase der Gefäßwand. Es stellt ein wichtiges Organ mit autokrinen und parakrinen Eigenschaften dar, das den Gefäßtonus reguliert und entscheidenden Einfluß auf die zelluläre Zusammensetzung der Gefäße ausübt. Durch seine strategische Lage zwischen vorbeiströmendem Blut und Gefäßwand interagiert das Endothel mit den zellulären und humoralen Bestandteilen beider Kompartimente. Zu den wichtigsten physiologischen Funktionen des Endothels gehört die Regulation des Gefäßtonus, die Kontrolle des Gefäßwachstums, die Vermittlung leukozytenadhäsiver Prozesse sowie die Aufrechterhaltung eines antithrombotischen und profibrinolytischen Zustands.
Eine der zentralen und bis heute am besten charakterisierten Substanzen, die vom Endothel gebildet wird und an einer Vielzahl der humoralen und zellulären Interaktionen beteiligt ist, stellt das Stickstoffmonoxid (NO) dar. NO wird im Endothel durch das Enzym NO-Synthase aus der Aminosäure L-Arginin gebildet und nach luminal und abluminal sezerniert. Zu den wichtigsten physiologischen Stimuli einer NO-Bildung zählen neben einer Reihe von zirkulierenden und lokal freigesetzten Substanzen insbesondere auch pysikochemische Stimuli wie pulsatile Dehnung der Gefäßwand und Scherkräfte. Das Endothel kann somit als ein Biosensor gesehen werden, der kontinuierlich auf unterschiedlichste Einflüsse reagiert und eine an den jeweiligen Bedarf angepaßte NO-Freisetzung garantiert.
Die bekannten klassischen kardiovaskulären Risikofaktoren, wie Hypercholesterinämie, arterielle Hypertonie, Nikotinkonsum und Diabetes mellitus, gehen mit einem Verlust der endothelvermittelten Vasodilatation einher. Dieser Verlust der NO-vermittelten Gefäßerweiterung ist das Kennzeichen einer „endothelialen Dysfunktion”, die bereits in der Frühphase der Atherosklerose nachweisbar und ursächlich mit dieser Erkrankung verbunden ist. Der endothelialen Dysfunktion kommt jedoch nicht nur im Rahmen der frühen Atherogenese eine zentrale Bedeutung zu, sondern auch bei den akuten Koronarsyndromen, bei denen sich auf dem Boden einer Plaqueruptur eine Thrombozytenaktivierung mit nachfolgender Thrombose und eine Gefäßkonstriktion entwickeln. So führt ein NO-Mangel zu einer gestörten Gefäßrelaxation bis hin zu einer Gefäßkonstriktion, zu einer gesteigerten Leukozytenadhäsion und Migration sowie zu einer Thrombozytenadhäsion und Aggregation.
Ein weiteres Kennzeichen atherosklerotischer Gefäße ist eine Endothelzellaktivierung, die durch eine Expression von Adhäsionsmolekülen wie „vascular cell adhesion moleculel” (VCAM-1), „intercellular adhesion molecule-1” (ICAM-1) und „endothelial-leukocyte adhesion molecule-1” (E-Selektin) charakterisiert ist und eine Ankopplung zirkulierender Leukozyten an das Endothel bewirkt. So ist die endotheliale Adhäsion von Monozyten mit nachfolgender Migration in den subendothelialen Raum ein zentraler Vorgang in der Entwicklung von frühen atherosklerotischen Läsionen („fatty streaks”), die durch eine Ansammlung von Schaumzellen und Lipidablagerungen gekennzeichnet sind. Im subendothelialen Raum transformieren diese Zellen dann zu Makrophagen, die sich durch eine unkontrollierte Aufnahme von oxidiertem LDL über den Scavenger-Rezeptor zu den typischen Schaumzellen entwickeln. Zytokine, oxidiertes LDL und möglicherweise auch ein Befall mit Chlamydia pneumoniae oder anderen Erregern bewirken eine Entzündung der Gefäßwand mit der Folge einer kontinuierlichen Endothelzellaktivierung, was wiederum die Vorgänge der Plaqueentwicklung bis hin zur Plaqueruptur unterhält. Die endotheliale Dysfunktion und eine Endothelzellaktivierung, bedingt durch die kardiovaskulären Risikofaktoren und entzündliche Gefäßprozesse, bilden damit die Basis für die Entwicklung der Atherosklerose und akuter Koronarsysndrome.
Abstract
The vascular endothelium is the inner lining of all blood vessels and serves as an important autocrine and paracrine organ, that regulates vascular wall functions. Because of its strategic location between the circulating blood and the vascular wall, the endothelium interacts with cellular and neurohumoral mediators, thus controlling vascular contractile state and cellular composition. The vascular endothelium maintains vascular homeostasis by modulating blood vessel tone, by regulating local cellular growth and extracellular matrix deposition and by controlling hemostatic as well as inflammatory responses. One of the best characterized and most important substances released from the endothelium is nitric oxide (NO). NO is a soluble gas wich is continuously synthesized from the amino acid L-arginine in endothelial cells by the constitutively expressed nitric oxide synthase. The most important stimuli represent physical factors such as shear stress and pulsatile stretching of the vessel wall as well as circulating and locally released vasoactive substances. The endothelium can be seen as a biosensor, reacting to a large variety of stimuli and therefore maintaining adequate NO release. A large number of risk factors for atherosclerosis including hypercholesterolemia, systemic hypertension, smoking and diabetes have been associated with impaired endothelial NO-mediated vasodilation. “Endothelial dysfunction” is an early marker of atherosclerosis and may be closely related to the disease process. In acute coronary syndroms dysfunctional endothelium may trigger the devastating event of plaque rupture by promoting adhesion of leukocytes, vasoconstriction, activation of platelets and thrombos formation.
Atherosclerotic blood vessels are further characterized by activation through zytokines and expression of cellular adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and endothelial-leukocyte adhesion molecule-1 (E-Selectin). After adhesion to the endothelium mononuclear cells migrate to the subendothelial space to take up oxidized LDL, thus transforming into foam cells, a hall mark of early atherosclerotic lesions. A number of conditions including infection with Chlamydia pneumoniae may cause continuous activation of the endothelium and inflammation of the vessel wall, Continuous endothelial dysfunction and activation, caused by risk factors and infection, represent the basis for atherogenesis and acute coronary syndromes.
Literatur
Anderson TJ, Meredith I, Yeung AC, et al. The effect of cholesterol-lowering and antioxidant therapy on endothelium-dependent coronary vasomotion. N Engl J Med 1995;332:488–93.
Beckman JS, Ye ZY, Anderson PG, et al. Extensive nitration of protein tyrosines in human atherosclerosis detected by immunohistochemistry. Hoppe-Seylers Z Physiol Chem 1994;375:81–8.
Bevilacqua MP. Endothelial-leucocyte adhesion molecules. Ann Rev Immunol 1993;11:767–804.
Boulanger CM, Tanner FC, Bea ML, et al. Oxidized low density lipoproteins induce mRNA expression and release of endothelin from human and porcine endothelium. Circ Res 1992;70:1191–7.
Bredt DS, Hwang PH, Glatt C, et al. Cloned and expressed nitric oxide synthase structurally resembles cytochrome P-450 reductase. Nature 1991;351:714–8.
Buttery LD, Springall DR, Chester AH, et al. Inducible nitric oxide synthase is present within human atherosclerotic lesions and promotes the formation and activity of peroxynitrite. Lab Invest 1996;75:77–85.
Campbell LA, O’Brien ER, Cappuccio AL, et al. Detection of Chlamydia pneumoniae TWAR in human coronary atherectomy tissues. J Infect Dis 1995;172:585–8.
Cayatte AJ, Palacino JJ, Horten K, et al. Chronic inhibition of nitric oxide production accelerates neointima formation and impairs endothelial function in hypercholesterolemic rabbits. Arterioscler Thromb 1994;14:753–9.
Celermajer DS, Sorensen KE, Gooch VM, et al. Noninvasive detection of endothelial dysfunction in children and adults at risk of atherosclerosis. Lancet 1992;340:1111–5.
Cibulski MI, Gimbrone MA Jr. Endothelial expression of mononuclear leukocyte adhesion molecule during atherogenesis. Science 1991;251:788–91.
Cohen RA, Zitnay KM, Haudenschild CC, et al. Loss of selective endothelial cell vasoactive functions caused by hypercholesterolemia in pig coronary arteries. Circ Res 1988;63:903–10.
Collins P, Rosano GMC, Sarrel PM, et al. 17β-estradiol attenuates acetylcholine-induced coronary artery constriction in women but not in men with coronary heart disease. Circulation 1995;92:24–30.
Cooke JP, Singer AH, Tsao P, et al. Antiatherogenic effects of L-arginine in the hypercholestrolemic rabbit. J Clin Invest 1992;90:1168–72.
Cox DA, Vita JA, Treasure CB, et al. Atherosclerosis impairs flow-mediated dilation of coronary arteries in humans. Circulation 1989;80:458–65.
Creager MA, Cooke JP, Mendelsohn ME, et al. Impaired vasodilation of forearm resistance vessels in hypercholesterolemic humans. J Clin Invest 1990;86:228–34.
Drexler H, Zeiher AM, Meinzer K, et al. Correction of endothelial dysfunction in coronary microcirculation of hypercholesterolemic patients by L-arginine. Lancet 1991;338:1546–50.
Drexler H, Zeiher AM, Wollschläger H, et al. Flow-dependent coronary artery dilatation in humans. Circulation 1989;80:466–74.
Drexler H, Zeiher AM, Köster W, et al. Endothelial dysfunction in the coronary circulation in hypercholesterolemia: effect of high HDL-cholesterol. Circulation 1992;86:Suppl 1:467.
Egashira K, Kai HY, et al. Reduction in serum cholesterol with pravastatin improves endothelium-dependent coronary vasomotion in p. J Infect Dis 1995;172:585–8.
Freiman PC, Mitchell GC, Heistad DD, et al. Atherosclerosis impairs endothelium-dependent vascular relaxation to acetylcholine and thrombin in primates. Circ Res 1986;58:783–9.
Furchgott RF, Zawadzki JV. The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature 1980;228:373–6.
Garg UC, Hassid A. Nitric oxide-generating vasodilators and 8-bromo-cyclic guanosine monophosphate inhibit mitogenesis and proliferation of cultured rat vascular smooth muscle cells. J Clin Invest 1989;83:1774–7.
Gruetter CA, Gruetter DY, Lyon JE, et al. Relationship between cyclic guanosine 3′:5′-monophosphate formation and relaxation of coronary arterial smooth muscle by glyceryl trinitrate, nitroprusside, nitrite and nitric oxide: effects of methylene blue and methemoglobin. J Pharmacol Exp Ther 1981;219:181–6.
Gryglewski RJ, Palmer RMJ, Moncada S. Superoxide anion is involved in the breakdown of edndothelium-derived vascular relaxing factor. Nature 1986;320:454–6.
Heitzer T, Just H, Münzel T. Antioxidant vitamin C improves endothelial dysfunction in chronic smokers. Circulation 1996;94:6–9.
Hirata K, Miki N, Kuroda Y, et al. Low concentration of oxidized low density lipoprotein and lysophosphatidylcholine upregulate constitutive nitric oxide synthase mRNA expression in bovine aortic endothelial cells. Circ Res 1995;76:958–62.
Huang PL, Huang Z, Mashimo H, et al. Hypertension in mice lacking the gene for endothelial nitric oxide synthase. Nature 1995;377:239–42.
Ignarro LJ, Buga GM, Wood KS, et al. Endothelium-derived relaxing factor produced and released from artery and vein is nitric oxide. Proc Natl Acad Sci USA 1987;84:9265–9.
Kubes P, Suzuki M, Granger DN. Nitric oxide: an endogenous modulator of leukocyte adhesion. Proc Natl Acad Sci USA 1991;88:4651–5.
Lamas S, Marsden PA, Li GK, et al. Endothelial nitric oxide synthase: molecular cloning and characterization of a distinct constitutive enzyme isoform. Proc Natl Acad Sci 1992;89:6348–52.
Lerman A, Holmes DR Jr, Bell MR, et al. Endothelin in coronary endothelial dysfunction and early atherosclerosis in humans. Circulation 1995;92:2426–31.
Lerman A, Edwards BS, Hallett JW, et al. Circulating and tissue endothelin immunoreactivity in advanced atherosclerosis. N Engl J Med 1991;325:997–1001.
Lerman AJ, Burnett JC Jr. Intact and altered endothelium in regulation of vasomotion. Circulation 1992;86:1112–9.
Leung WH, Pak LC, Wong CK. Beneficial effects of cholesterollowering therapy on coronary endothelium-dependent relaxation in hypercholesterolemic patients. Lancet 1993;341:1496–500.
Levine GN, Frei B, Koulouris SN, et al. Ascorbic acid reverses endothelial vasomotor dysfunction in patients with coronary artery disease. Circulation 1996;93:1107–13.
Liao JK. Inhibition of Gi proteins by low density lipoprotein attenuates bradykinin-stimulated release of endothelial-derived nitric oxide. J Biol Chem 1994;269:19528–33.
Liao JK, Shin WS, Lee WY, et al. Oxidized low density lipoprotein decreases the expression of endothelial nitric oxide synthase. J Biol Chem 1994;270:319–24.
Libby P. Inflammatory and immune mechanisms in atherogenesis. In: Leaf A, Weber P, eds. Atherosclerosis reviews. New York: Raven Press, 1990:79–89.
Libby P, Clinton SK. The role of macrophages in atherogenesis. Curr Opin Lipidol 1993;4:355–63.
Lüscher TF. Endothelium in the control of vascular tone and growth: role of local mediators and mechanical forces. Blood Pressure 1994;1:Suppl:18–22.
Lyons CR, Orloff GJ, Cunningham JM. Molecular cloning and functional expression of an inducible nitric oxide synthase from a murine macrophage cell line. J Biol Chem 1992;267:6370–4.
Martin-Nizard F, Houssaini HS, Lestavel-Delattre S, et al. Modified low density lipoproteins activate human macrophages to secrete immunoreactive endothelin. FEBS Lett 1991;293:127–30.
McLenachan JM, Williams JK, Fish RD, et al. et al. Loss of flowmediated endothelium-dependent dilation occurs early in the development of atherosclerosis. Circulation 1991;84:1273–8.
Minor RL, Myers PR, Guerra R, et al. Diet-induced atherosclerosis increases the release of nitrogen oxides from rabbit aorta. J Clin Invest 1990;86:2109–16.
Moncada S, Palmer RM, Higgs EA. Nitric oxide physiology, pathophysiology and pharmacology. Pharmacol Rev 1991;43:109–42.
Moroi M, Zhang L, Yasuda T, et al. Interaction of genetic deficiency of endothelial nitric oxide, gender and pregnancy in vascular reponse to injury in mice. J Clin Invest 1998;101:1225–32.
Murad F. Regualtion of cytosolie guanylyl cyclase by nitric oxide: the NO-cyclic GMP signal transduction system. Adv Pharmacol 1994;26:19–33.
Myers RP, Minor RL Jr, Fuerra R Jr, et al. Vasorelaxant properties of the endothelium-derived relaxant factor more closely resemble S-nitrosocysteine than nitric oxide. Nature 1990;345:161–3.
Nishida K, Harrison DG, Navas JP, et al. Molecular cloning and characterization of the constitutive bovine aortic endothlial cell nitric oxide synthase. J Clin Invest 1992;90:2092–6.
Niu XF, Smith CW, Kubes P. Intracellular oxidative stress induced by nitric oxide synthesis inhibition increases endothelial cell adhesion to neutrophils. Circ Res 1994;74:1133–40.
Ohara Y, Peterson TE, Sayegh HS, et al. Dietary correction of hypercholesterolemia in the rabbit normalizes endothelial superoxide anion production. Circulation 1995;92:898–903.
Ohara Y, Peterson TE, Harrison DG. Hypercholesterolemia increases endothelial superoxide anion production. J Clin Invest 1993;91:2546–51.
Palmer RMJ, Ferridge AG, Moncada S. Nitric oxide release accounts for the biological activity of endothelium-derived relaxing factor. Nature 1987;327:524–6.
Panza JA, Quyyumi AA, Callahan TS, et al. Effect of antihypertensive treatment on endothelium-dependent vascular relaxation in patients with essential hypertension. J Am Coll Cardiol 1993;21:1145–51.
Pearson JD. Baillers Clin Haemat 1994;7:441–52.
Pohl U, Dezsi L, Simon B, et al. Selective inhibition of endothelium-dependent dilation in resistance-sized vessels in vivo. Am J Physiol 1987;253:H234–9.
Radomski MW, Palmer RMJ, Moncada S. Comparative pharmacology of endothelium-derived relaxing factor, nitric oxide and prostacyclin in platelets. Br J Pharmacol 1987;92:181–7.
Radl R, Beckman JW, Bush KM, et al. Peroxynitrite induced membrane lipid peroxidation: the cytotoxic potential of superoxide and nitric oxide. Arch Biochem Biophys 1991;288:481–7.
Reddy KG, Nair RN, Sheehan HM, et al. Evidence that selective endothelial dysfunction may occur in the absence of angiographic or ultrasound atherosclerosis in patients with risk factors for atherosclerosis. J Am Coll Cardiol 1994;23:833–43.
Rubani GM, Romero JC, Vanhoutte PM. Flow-induced release of endothelium-derived relaxing factor. Am J Physiol 1986;250:H1145–9.
Saikku P, Leinonen M, Mattila K, et al. Serological evidence of an association of a novel Chlamydia, TWAR, with chronic coronary heart disease and acute myocardial infarction. Lancet 1988;2:983–6.
Schreck R, Albermann K, Baeuerle PA. Nuclear factor-κB: an oxidative stress-responsive transcription factor of eukaryotic cells. Free Radicals Res Commun 1992;17:221–37.
Shepherd J, Cobbe SM, Ford I, et al. Prevention of coronary heart disease with pravastatin in men with hypercholesterolemia. West of Scotland Coronary Prevention Study Group. N Engl J Med 1995;333:1301–7.
Simon BC, Cunningham LD, Cohen RA. Oxidized low density lipoproteins cause contraction and inhibit endothelium-dependent relaxation in the pig coronary artery. J Clin Invest 1990;86:75–9.
Simon BC, Haudenschild CC, Cohen RA. Preservation of endothelium-dependent relaxation in atherosclerotic rabbit aorta by probucol. J Cardiovasc Pharmacol 1993;21:893–901.
Steinberg D. Oxidative modification of LDL and atherogenesis. Circulation 1997;95:1062–71.
Treasure CB, Klein JL, Weintraub WS. Beneficial effects of cholesterol-lowering therapy on the coronary endothelium in patients with coronary artery disease. N Engl J Med 1995;332:481–7.
Tsao P, McEvoy LM, Drexler H, et al. Enhanced ednothelial adhesiveness in hypercholesterolemia is attenuated by L-arginine. Circulation 1994;89:2176–82.
Vita JA, Treasure CB, Nabel EG, et al. Coronary vasomotor response to acetylcholine relates to risk facotrs for coronary artery disease. Circulation 1990;81:491–7.
Vita JA, Treasure CB, Ganz P, et al. Control of shear stress in the epicardial coronary arteries of humans: impairment by atherosclerosis. J Am Coll Cardiol 1989;14:1193–9.
Von der Leyen HE, Gibbons GH, Morishita R, et al. Gene therapy inhibiting neointimal vascular lesion: in vivo transfer of endothelial cell nitric oxide synthase gene. Proc Natl Acad Sci USA 1995;92:1137–41.
Watt GF, Lewi B, Brunt JN. Effects of coronary artery disease of lipid-lowering diet, or diet plus cholestyramine, in the St. Thomas’ Atherosclerosis Regression Study (STARS). Lancet 1992;339:563–9.
Weissberg PL, Witchell C, Davenport AP, et al. The ednothelin peptides ET-1, ET-2, ET-3, and sarafotoxin S6b are co-mitogenic with platelet-derived growth factor for vascular smooth muscle cells. Atherosclerosis 1990;85:257–62.
Werner-Felmayer G, Werner ER, Fuchs D. Tetrahydrobiopterin-dependent formation of nitrite and nitrate in murine fibroblasts. J Exp Med 1990;172:1599–607.
Werns SW, Walton JA, Hsia HH, et al. Evidence of endothelial dysfunction in angiographically normal coronary arteries of patients with coronary artery disease. Circulation 1989;79:287–91.
Yeung AC, Vekshtein VL, Krantz DS, et al. The effect of atherosclerosis on the vasomotor response of coronary arteries to mental stress. N Engl J Med 1991;325:1551–6.
Zeiher MA, Drexler H, Wollschläger H, et al. Coronary vasomotion in response to sympathetic stimulation in humans: importance of the functional integrity of the endothelium. J Am Coll Cardiol 1989;14:1181–90.
Zeiher AM, Goebel H, Schachinger V, et al. 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;91:941–7.
Zhao XQ, Brown BG, Hillger L. Effects of intensive lipid lowering therapy on on the coronary arteries of asymptomatic subjects with elevated apolipoprotein B. Circulation 1993;88:2744–53.
4S-Trial: Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S). Lancet 1994;344:1383–9.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Simon, B.C., Noll, B. & Maisch, B. Endotheliale Dysfunktion — eine Bestandsaufnahme und Ansätze zur Therapie. Herz 24, 62–71 (1999). https://doi.org/10.1007/BF03043820
Issue Date:
DOI: https://doi.org/10.1007/BF03043820