elastin and Arteriosclerosis

Vascular calcification occurred as the last step of arteriosclerosis makes a lot of disturbances on vascular function and should influence on the worsening of the vascular diseases. Calcium is the main component of the vascular calcification like bone, and one of causes of vascular calcification should be the hypoparathyroidism due to the lowering of serum calcium and the following calcium paradox seen in osteoporosis. Bone calcium must shift to the arterial wall from the bone. Medial calcification could be formed under the molecular regulatory control like in bone by differentiated osteoblast or chondroblast from pericyte like cell origin smooth muscle cell. Many substances such as osteopontine, osteocalcine, bone morphogenetic protein 2, matrix Gla protein and alkaliphosphatase were found in calcified area. In intimal calcification, degenerated elastin and macrophage originated calcification were found. In the process of degeneration of elastin polypentapeptide structure in elastin can be easily conbined to Ca(2+), elastin-Ca(2+) complex is neutralized by PO4(2-) and calcium phosphate is accumulated in degenerated elastin.

Topics: Alkaline Phosphatase; Aortic Diseases; Arteriosclerosis; Bone Morphogenetic Protein 2; Calcinosis; Calcium; Calcium-Binding Proteins; Elastin; Extracellular Matrix Proteins; Humans; Hypoparathyroidism; Macrophages; Matrix Gla Protein; Osteocalcin; Osteopontin; Osteoporosis

Animal models of large artery wall stiffness fall into two categories: firstly those that slowly develop multifactorial vascular dysfunction spontaneously, such as the ageing rat. The second type of model consists of those in which a specific pathology is induced by surgical, chemical, or genetic means. Such models are based on a short-term, highly traumatic insult to the arterial wall of a young animal and its acute reaction to such insult. This is very different from the human situation in which changes in wall stiffness arise from the long-term accumulation of relatively minor episodes of vascular insult in the vulnerable elderly.

Topics: Animals; Arteries; Arteriosclerosis; Calcinosis; Collagen; Disease Models, Animal; Elastin; Humans; Hypertension; Neurotransmitter Agents; Pancreatic Elastase; Renin-Angiotensin System; Vascular Resistance

Four classes of agents capable of producing human illness have been identified: toxicity, heredity, infection and deficiency. Examples of how members of these classes of etiologic agents can cooperate to produce illness were shown. The copper deficiency theory of ischemic heart disease and the homocysteine theory of arteriosclerosis were examined using concepts about cooperation. The Western diet so closely associated with these illnesses often is low in copper. Copper deficiency decreases the activity of methionine synthase which contributes to elevation of homocysteine, and of paraoxonase which impairs hydrolysis of homocysteine thiolactone, an inhibitor of lysyl oxidase. This copper-dependent enzyme initiates the cross-linking of collagen and elastin in arteries and bone. High homocysteine also impairs superoxide dismutase, a copper-dependent enzyme important in oxidative defense. Some genes affecting paraoxonase activity may respond to dietary copper. The copper deficiency theory of ischemic heart disease and the homocysteine theory of arteriosclerosis are inextricably entwined.

Topics: Animals; Arteriosclerosis; Aryldialkylphosphatase; Collagen; Copper; Diet; Elastin; Heart Diseases; Homocysteine; Humans; Malnutrition; Myocardial Ischemia

The progressive stiffening of the large arteries in humans that occurs during aging constitutes a potential risk factor for increased cardiovascular morbidity and mortality, and is accompanied by an elevation in systolic blood pressure and pulse pressure. While the underlying basis for these changes remains to be fully elucidated, factors that are able to influence the structure and composition of the extracellular matrix and the way it interacts with arterial smooth muscle cells could profoundly affect the properties of the large arteries. Thus, while age and sex represent important factors contributing to large artery stiffening, the variation in growth-stimulating factors and those that modulate extracellular production and homeostasis are also being increasingly recognized to play a key role in the process. Therefore, elucidating the contribution that genetic variation makes to large artery stiffening could ultimately provide the basis for clinical strategies designed to regulate the process for therapeutic benefit.

Topics: Arteries; Arteriosclerosis; Collagen Type I; Cytochrome P-450 CYP11B2; Elasticity; Elastin; Endothelins; Extracellular Matrix Proteins; Fibrillins; Genetic Predisposition to Disease; GTP-Binding Proteins; Humans; Matrix Metalloproteinase 3; Matrix Metalloproteinase 9; Matrix Metalloproteinases, Secreted; Microfilament Proteins; Nitric Oxide Synthase; Polymorphism, Genetic; Receptors, Endothelin; Renin-Angiotensin System

Topics: Aging; Arteriosclerosis; Blood Pressure; Calcinosis; Cholesterol; Collagen; Diastole; Elastin; Endothelium, Vascular; Humans; Myocardial Infarction

HUNDREDS OF THEORIES: The mechanisms of aging have been intensively studied since the middle of the last century on cellular and molecular level in experimental studies, case reports and epidemiological estimations. They have also generated a number of speculations and over 300 theories. THE ROLE OF GENES: Genetic data suggest an indirect determinism through the enhancement of antiradical defense mechanisms or by the presence of genes enhancing age-related diseases. One of the best examples is the dose-effect of genes coding for apolipoprotein E(4) (epsilon (4)), its presence in 0, 1 or 2 copies proportionally increases the risk of Alzheimer-type dementia but also atherosclerotic diseases. THE UNFORESEABILITY OF NATURE: However, it appears more and more clearly that epigenetic mechanisms (escaping direct genetic control) would be more directly implied in the decline of physiological functions with age. Several examples of such mechanisms are discussed and may be attributed to "negligence of nature' during the development of multicellular eukaryotic organisms. However, their very nature makes it possible to propose specific therapeutic interventions in order to slow down the effects of such mechanisms indirectly coded in the genome.

Topics: Adolescent; Adrenal Cortex Hormones; Adult; Age Factors; Aged; Aged, 80 and over; Aging; Alzheimer Disease; Animals; Arteriosclerosis; Child; Columbidae; Elastin; Female; Fibronectins; Hormones; Humans; Longevity; Male; Mice; Middle Aged; Rats; Risk Factors

Abdominal aortic aneurysms and their management remain a significant health problem that is likely to assume greater importance with the expansion of the elderly population. Elastin fibres degradation and extracellular matrix remodelling seems to be the basic process in aneurysm formation. Recent investigations revealed the principal role of elastin-laminin receptor in extracellular matrix remodelling in aging and atherosclerosis. The correlation between events observed in animal aneurysm models, human aneurysms and in experiments on elastin-laminin receptor properties was discussed to propose the hypothesis about the role of elastin peptides and elastin-laminin receptor in aortic aneurysm formation.

Topics: Aging; Animals; Aortic Aneurysm, Abdominal; Arteriosclerosis; Elastin; Extracellular Matrix; Humans; Receptors, Cell Surface; Receptors, Laminin

With aging we assist to alterations in the vascular structure and function. One important factor in these vascular wall changes is the degradation of the elastin fibre major protein: elastin. Elastin peptides derived from the degradation are present in human sera. Elastin peptides induce on fibroblasts, phagocytic cells, lymphocytes, smooth muscle cells and endothelial cells, a variety of biological effects mediated by the elastin-laminin receptor which has been demonstrated to be present on the membrane of these cells. The transduction pathway of the ELR receptor involves the activation of phospholipase C (PLC) by a pertussis toxin sensitive G-protein. PLC induces the production of inositol trisphosphate (IP3) leading to the increase of the intracellular free calcium on one hand, and of diacylglycerol (DAG) which stimulates the translocation to the membrane of PKC leading to the phosphorylation of members of the MAPK family, such as p42/p44 MAPK. A progressive age dependent uncoupling of the elastin-laminin receptor occurs impairing its transduction pathway and which results in alteration of the calcium signaling and loss in calcium homeostasis of the cells. These alterations in the signal transduction of the elastin-laminin receptor result in modified activities of parenchymal and phagocytic cells with aging, such as free radical production and elastase release. Thus, these age-related alterations in the elastin-laminin receptor signal transduction may be involved in the atherogenesis.

Topics: Aging; Arteriosclerosis; Blood Vessels; Elastin; Enzyme Activation; GTP-Binding Proteins; Humans; Pertussis Toxin; Phagocytes; Receptors, Cell Surface; Receptors, Laminin; Signal Transduction; T-Lymphocytes; Type C Phospholipases; Virulence Factors, Bordetella

Vascular calcification occurs at two distinct sites within the vessel wall: the intima and the media. Intimal calcification occurs in the context of atherosclerosis, associated with lipid, macrophages and vascular smooth muscle cells, whereas medial calcification can exist independently of atherosclerosis and is associated with elastin and vascular smooth muscle cells.. In this review we compare intimal and medial calcification, particularly discussing the mechanisms which may be responsible for each type of calcification. Similar mechanisms probably initiate and regulate both forms of calcification including the generation of matrix vesicles/apoptotic bodies and local expression of mineralization-regulating proteins. However, since different modifying agents such as lipids in the intima and elastin in the media are present at the sites of calcification and are associated with particular diseases, this implies that the etiologies of these processes differ. For example, intimal calcification is associated with atherosclerosis while medial calcification occurs commonly in the diabetic neuropathic leg.. Since both types of calcification correlate with significant morbidity and mortality, we discuss the different types of calcification in terms of their clinical importance.

Topics: Adult; Age Factors; Aged; Animals; Apoptosis; Arteriosclerosis; Calcinosis; Cells, Cultured; Coronary Artery Disease; Diabetic Neuropathies; Elastin; Endothelium, Vascular; Gene Expression; Humans; Lipid Metabolism; Mice; Mice, Knockout; Muscle, Smooth, Vascular; Phenotype; Risk Factors; Tunica Intima

Elastases are proteinases capable of solubilizing fibrous elastin. They may belong to the class of serine proteinases, cysteine proteinases and metalloproteinases. Mammalian elastases occur mainly in the pancreas and the phagocytes. Among non-mammalian elastases there is a great variety of bacterial metallo and serine elastases. The elastolytic activity varies from one elastase to another and is usually not correlated with the catalytic efficiency of these proteinases. One may measure this activity using native or labelled elastins. With pure elastases one may use synthetic substrates. There is a large number of natural (proteins) and synthetic elastase inhibitors. Elastases play a pathologic role in pulmonary emphysema, cystic fibrosis, infections, inflammation and atherosclerosis.

Topics: alpha 1-Antitrypsin Deficiency; alpha-Macroglobulins; Animals; Arteriosclerosis; Arthritis, Rheumatoid; Bacterial Proteins; Catalysis; Cathepsin G; Cathepsins; Elastin; Enzyme Inhibitors; Fibroblasts; Glycosaminoglycans; Humans; Leukocytes; Mammals; Organ Specificity; Pancreas; Pancreatic Elastase; Phagocytes; Polynucleotides; Pseudomonas Infections; Pulmonary Emphysema; Serine Endopeptidases; Species Specificity; Substrate Specificity

Topics: Aorta, Abdominal; Aortic Aneurysm, Abdominal; Aortic Diseases; Aortic Rupture; Arteriosclerosis; Collagen; Elastin; Humans; Metalloendopeptidases

This review proposes reinvestigation of a topic studied in the author's laboratory over the last decades concerning the age-dependent modifications of the vascular extracellular matrix (ECM) as related to atherogenesis and its recognized risk-factors: blood lipids, lipoproteins. Most salient previous results are confronted with recent publications in this field. Age-dependent modifications of the vascular wall discussed in this review include upregulation of elastolytic enzymes, demonstrated for the first time in the vascular wall in this laboratory, matrix biosynthesis and receptor function. The progressive deposition of lipids in elastic tissues as well as the addition of lipoproteins or lipids to cell and organ cultures were shown to modify matrix biosynthesis and upregulate elastase expression. Lipid-elastin interactions exhibit a great deal of specificity as shown by the nature and amount of lipids accumulating in elastin in vivo and in vitro. Recent epidemiological studies (the EVA study) enables the confrontation of blood lipid parameters with matrix related components (serum elastase and inhibitors, elastin peptides, fibronectin) in the same blood samples. The elastin laminin receptor present on vascular cells was shown to trigger NO dependent vasodilation, and downregulation of cholesterol synthesis. Both of these functions decrease or disappear with age except the upregulation of elastase release which is preserved and increased. Recent experiments extended these findings to T-lymphocytes present also in the atherosclerotic plaque. Finally several recent publications are analyzed which give more precision on the cellular mechanisms underlying the above-described modifications.

Topics: Adult; Aged; Aging; Animals; Arteries; Arteriosclerosis; Cholesterol; Elastin; Extracellular Matrix; Female; Humans; Male; Middle Aged; Pancreatic Elastase; Rabbits; Risk Factors; Vasodilation

Vascular cells, as well as monocytes, neutrophils, and lymphocytes which may infiltrate vascular walls and tissues express a multifunctional 67 kD protein which also serves as a subunit of the cell surface "elastin receptor". This protein differs structurally and functionally from other matrix adhesion molecules. Unlike the integrins or cadherins, it is not a transmembrane molecule, but can be immobilized on the cell surface by association with two other membrane-anchored proteins. Once expressed on the cell surface, it may mediate cell-matrix interaction in a calcium-independent manner. Unlike most integrins, which recognize the linear sequence on the matrix ligands (RGD), it recognizes the secondary structure of the matrix macromolecules and binds to several non identical domains on different matrix components, as long as they form the appropriate hydrophobic conformation. Similarly to the transmembrane selectins, the 67 kD protein has lectin-like properties with the galactosugars' binding specificity. However, binding of galactosugar-bearing ligands interrupts its contacts with matrix proteins and displaces the 67 kD protein from the cell surface. Moreover, the 67 kD protein also serves as an intracellular chaperone which facilitates secretion of tropoelastin and assembly of elastic fibers. In this review I will address the role of this 67 kD protein in mechanisms of mutual interaction between vascular smooth muscle cells, infiltrating leukocytes, and several components of extracellular matrix during the development of heart-transplant associated arteriosclerosis.

Topics: Animals; Arteriosclerosis; Cell Communication; Elastin; Extracellular Matrix; Heart Transplantation; Humans; Receptors, Cell Surface

Topics: Arteries; Arteriosclerosis; Cholesterol; Elastin; Humans; Lipids; Muscle, Smooth, Vascular

In some pathological states such as therosclerosis tissue destruction may be accelerated due to uncontrolled protease release of polymorphonuclear leukocytes and other events such as decreased concentration and/or the inactivation of main protease inhibitor molecules in the serum. In this study, the authors measured the elastase release of polymorphonuclear leukocytes which increased in atherosclerosis independently of the patients aged compared to healthy young subjects. These findings were similar to the response of polymorphonuclear leukocytes separated from healthy elderly subjects. Simultaneously, the main plasma proteinase inhibitors such as alpha-1-antitrypsin and alpha-2-macroglobulin in healthy and atherosclerotic subjects were determined. alpha-1-antitrypsin did not decrease significantly, whereas alpha-2-macroglobulin did in sera of atherosclerotic patients compared to age matched subjects (p < 0.05). In contrast, the activity of porcine pancreatic elastase was more effectively neutralized by the plasma obtained from healthy subjects suggesting diminished antiprotease activity of sera obtained from patients. The authors concluded that increased elastase release and decreased antiproteinase activity should be considered in atherosclerotic arterial wall damage. The similarity of the results in aged and therosclerotic subjects suggests that arteriosclerosis is an earlier aging process.

Topics: Arteriosclerosis; Elastin; Female; Humans; Leukocyte Elastase; Leukocytes; Male; Middle Aged; Pancreatic Elastase; Peptides; Protease Inhibitors

Topics: Aging; Aorta; Aortic Aneurysm, Abdominal; Arteriosclerosis; DNA, Complementary; Elastic Tissue; Elastin; Enzyme Induction; Humans; Leukocyte Elastase; Neutrophils; RNA, Messenger; Serine Endopeptidases

Past concepts of aneurysmal dilatation as a passive process of attenuation are oversimplified and inaccurate. Aneurysm formation is a complex remodeling process that involves both synthesis and degradation of matrix proteins. Interstitial procollagen gene expression is increased in AAA compared to AOD or normal aorta, whereas tropoelastin gene expression is decreased in both AOD and AAA. The medial elastin network is disrupted and discontinuous in small AAA. Thus, the growth rate of an established AAA may well relate to the balance between collagen synthesis and degradation. Although the increased procollagen expression found in AAA may represent a compensatory response, understanding the factors that modulate matrix metabolism in AAA may allow for development of pharmacologic strategies which effectively inhibit the growth of small aneurysms.

Topics: Animals; Aorta; Aortic Aneurysm, Abdominal; Aortitis; Arteriosclerosis; Cattle; Collagen; Elastin; Extracellular Matrix Proteins; Humans; Platelet-Derived Growth Factor; RNA, Messenger; Tensile Strength

Topics: Aortic Aneurysm, Abdominal; Arteriosclerosis; Collagen; Elastin; Humans; Prevalence

This report is the continuation of two earlier reports that defined human arterial intima and precursors of advanced atherosclerotic lesions in humans. This report describes the characteristic components and pathogenic mechanisms of the various advanced atherosclerotic lesions. These, with the earlier definitions of precursor lesions, led to the histological classification of human atherosclerotic lesions found in the second part of this report. The Committee on Vascular Lesions also attempted to correlate the appearance of lesions noted in clinical imaging studies with histological lesion types and corresponding clinical syndromes. In the histological classification, lesions are designated by Roman numerals, which indicate the usual sequence of lesions progression. The initial (type I) lesion contains enough atherogenic lipoprotein to elicit an increase in macrophages and formation of scattered macrophage foam cells. As in subsequent lesion types, the changes are more marked in locations of arteries with adaptive intimal thickening. (Adaptive thickenings, which are present at constant locations in everyone from birth, do not obstruct the lumen and represent adaptations to local mechanical forces). Type II lesions consist primarily of layers of macrophage foam cells and lipid-laden smooth muscle cells and include lesions grossly designated as fatty streaks. Type III is the intermediate stage between type II and type IV (atheroma, a lesion that is potentially symptom-producing). In addition to the lipid-laden cells of type II, type III lesions contain scattered collections of extracellular lipid droplets and particles that disrupt the coherence of some intimal smooth muscle cells. This extracellular lipid is the immediate precursor of the larger, confluent, and more disruptive core of extracellular lipid that characterizes type IV lesions. Beginning around the fourth decade of life, lesions that usually have a lipid core may also contain thick layers of fibrous connective tissue (type V lesion) and/or fissure, hematoma, and thrombus (type VI lesion). Some type V lesions are largely calcified (type Vb), and some consist mainly of fibrous connective tissue and little or no accumulated lipid or calcium (type Vc).

Topics: Aneurysm; Arteriosclerosis; Blood Vessels; Calcium; Collagen; Coronary Artery Disease; Coronary Vessels; Elastin; Extracellular Matrix; Fibrinogen; Foam Cells; Humans; Lipid Metabolism; Lipoproteins; Lymphocytes; Muscle, Smooth, Vascular; Proteoglycans; Thrombosis; Tunica Intima

We now know our past concepts of AAA pathogenesis to be oversimplified and inaccurate. In fact, the metabolic activity of the aneurysm wall is markedly increased in comparison with normal aorta. It has become clear that AAAs result not from passive dilatation, but from a complex remodeling process involving both the synthesis and degradation of matrix proteins. Our understanding of this process has been advanced by applying molecular biology techniques. Although elastin fragmentation and medial attenuation remain the most striking histological features of AAA tissue, experimental and clinical evidence suggests that the adventitia, which is predominantly collagen, is capable of maintaining the dimensional stability of the aorta in the absence of the medial elastin network. Thus, although factors that result in fragmentation and attenuation of elastin may be important in the etiology of AAA, factors regulating the balance of collagen synthesis and degradation likely determine the rate of AAA progression. The resident inflammatory cells in AAA undoubtedly play an important pathological role in aortic dilatation. Thus, understanding the interaction between aortic mesenchymal cells (smooth muscle cells and fibroblasts) and inflammatory cells (lymphocytes and macrophages) should allow for the identification of genetic factors that predispose to AAA. In addition to the possibility of early identification of patients at risk for AAA, new insights into AAA pathogenesis might allow for development of pharmacological strategies for inhibiting expansion of small AAA.

Topics: Aorta, Abdominal; Aortic Aneurysm, Abdominal; Aortitis; Arteriosclerosis; Collagen; Elastin; Endopeptidases; Extracellular Matrix Proteins; Humans

The pathogenesis of abdominal aortic aneurysm involves many factors acting over time. However, destruction of elastin in the aortic wall is a key event that shifts the load produced by blood pressure on to collagen. This is exacerbated in the presence of hypertension. Smoking and age are further important factors, as is the site; elastic lamellae are relatively less common in the abdominal aorta. Once the shielding effect of elastin is lost, further dilatation and rupture of the aorta depend on the physical properties of the collagen present.

Topics: Age Factors; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Arteriosclerosis; Collagen; Elastin; Humans; Hypertension; Inflammation; Smoking

During pathologies such as arteriosclerosis and emphysema, degradation of elastin by elastases occurs and elastin peptides are produced. In order to evaluate elastin degradation, measurements of elastin peptide concentration in human blood were carried out. According to elastin peptides used for obtention of antibodies and for ELISA, the measured values are different. Elastin peptides have several biological effects: they are chemotactic, modify ion fluxes and several intracellular mechanisms.

Topics: Arteriosclerosis; Elastin; Humans; Peptides

The progression of atheroarteriosclerosis was shown to be age dependent. This designation covers two separate entities: arteriosclerosis, the progressive and diffuse hardening of the walls of arteries with loss of elasticity, and atheromatous plaque formation, which can start early in life according to nutrition and genetic factors (LDL-receptor expression). Lipoprotein-receptor interactions play a crucial role in lipidic plaque formation. There is, however, no indication that the diffuse hardening of the vascular wall would also be influenced by these mechanisms. We described recently a high-affinity receptor for elastin peptides, present on smooth muscle cells, fibroblasts, and also on monocytes and PMNs. When activated, this receptor will increase intracellular calcium. Circulating elastin peptides were determined by a sensitive Elisa method and found to be between 0.1 and 20 micrograms/ml, in the range of activation of the elastin receptor. They increase in obliterative arteriopathies and type IIb hyperlipidemia. Elastolysis accompanies aging and vascular pathology; the sensitivity of this receptor changes with age, intracellular Ca++ increases, but the receptor appears to be uncoupled from its normal transmission mechanism. These results may well explain the increasing diffuse calcification of the vessel wall. The previously demonstrated potentiation of cholesterol deposition in elastic fibers by calcium is in agreement with simultaneous deposition of calcium and lipids. The recent demonstration of the efficient competition of fibronectin for LDL in proteoglycan-LDL complexes suggests that this reaction may be involved in foam cell formation by the opsonization of LDL for phagocytosis. Fibronectin was shown to accumulate in atherosclerotic plaques. Altogether these recent results confirm the importance of cell-matrix interactions in atherogenesis and lead to a better understanding of the age dependence of these disease processes.

Topics: Aging; Animals; Arteriosclerosis; Blood Vessels; Elastin; Extracellular Matrix; Glycoproteins; Humans; Receptors, Cell Surface

Topics: Animals; Arteriosclerosis; Blood Vessels; Collagen; Connective Tissue; Elastin; Humans; Hypertension; Muscle, Smooth, Vascular

Atherosclerotic lipid deposits found in the core region of fibrous plaques are almost entirely extracellular, but it is not known whether they are derived from necrosis of cells containing accumulated lipid or from direct extracellular lipid accumulation. New evidence pertaining to this question has been obtained through the use of recently developed techniques for preserving and staining lipids in electron microscopy, and through a detailed morphologic and chemical examination of human aortic fibrolipid lesions, which are progenitor lesions for fibrous plaques. The evidence favours a substantial role, perhaps a dominant role, for extracellular lipid accumulation in the formation of the fibrous plaque core region.

Topics: Aorta; Arteriosclerosis; Cholesterol, LDL; Elastin; Humans; In Vitro Techniques; Lipids

Elastin in the most resistant fibrous protein of the organisms. Its degradation is catalysed by proteases designated as elastases. Elastic fibers appeared during phylogenesis at the level of the first Vertebrates and rendered possible the emergence of efficient circulatory and respiratory systems which were necessary for the development of the higher Vertebrates. Several pathological conditions, mostly age-dependent, are accompanied by the degradation of elastic fibers or their alteration due to increasing association with lipids and calcium salts. Several proteases (endopeptidases) of cellular origin were described over the last years, especially those of PMN leukocytes, platelets, monocytes-macrophages, smooth muscle cells and fibroblasts. Although less active on fibrous elastin than pancreatic elastase, these enzymes may well play an important role in the development of age-dependent pathologies such as athero-arteriosclerosis and emphysema. The involvement of cellular elastases in these pathologies is discussed in some detail. The age-dependent increase, both in vivo and in vitro of the elastase activity of fibroblasts and smooth muscle cells appears to play an important role in the modifications of cell behaviour observed in the above pathologies.

Topics: Aging; Animals; Arteriosclerosis; Elastin; Endopeptidases; Humans; Pancreatic Elastase

Recent concepts on the mechanisms of aging of extracellular matrix (EM) are reviewed as well as its involvement in age-associated diseases. Cell differentiation, histogenesis and organogenesis can be analyzed in terms of the program of the biosynthesis of EM macromolecules during development, maturation and aging. The most important biological role of EM is the integration of cells in tissues, of tissues in organs and of organs in the whole organism. EM can directly influence cell behavior through the contact between EM and the genome mediated by structural glycoproteins (fibronectin, laminin, elastonectin, etc.) interacting with other EM macromolecules (collagen, proteoglycans, elastin) and the cytoskeleton by trans-membrane receptors (integrins). Most age-associated diseases exhibit a deviation (qualitative or quantitative) from the normal program of EM biosynthesis. Three examples are analyzed in some detail: atherosclerosis, diabetes and malignant tumors. The degradation of elastic fibers catalyzed by cellular elastase-type enzymes is observed in atherosclerosis and also in emphysema and skin aging. Several of these enzymes were isolated and characterized from platelets, fibroblasts, smooth muscle cells and lipoproteins. The biosynthesis of some of them increases with age and facilitates cell migration. Plasma fibronectin increases with age exponentially. This increase is absent or strongly attenuated in diabetes and some cancers. Tissue fibronectin increases in diabetes, Werner syndrome and in the peritumoral desmoplastic reaction while most tumor cells can no more retain fibronectin on their membrane facilitating their movement in the organism. These examples demonstrate the importance of the study of cell matrix interactions for gerontology.

Topics: Aging; Arteriosclerosis; Cell Differentiation; Diabetes Mellitus; Elastin; Extracellular Matrix; Fibronectins; Humans; Neoplasms

Topics: Animals; Arteries; Arteriosclerosis; Collagen; Elastin; Glycosaminoglycans; Humans; Lipid Metabolism; Lipoproteins; Proteoglycans

Topics: Animals; Arteriosclerosis; Aspirin; Blood Platelets; Cell Division; Collagen; Coronary Artery Bypass; Dipyridamole; Elastin; Endothelium; Graft Occlusion, Vascular; Hemodynamics; Humans; Lipoproteins; Models, Cardiovascular; Muscle, Smooth, Vascular; Risk; Saphenous Vein; Thrombosis

Topics: Aged; Aging; Animals; Aorta; Arteries; Arteriosclerosis; Basement Membrane; Blood Platelets; Cell Adhesion; Child, Preschool; Collagen; Diet, Atherogenic; Elastin; Endothelium; Extracellular Matrix; Humans; Hyperlipidemias; Middle Aged; Muscle, Smooth, Vascular; Platelet Aggregation; Skin

In studies concerning risk factors for cardiovascular diseases, a number of reports have emphasized the influence of lipids, but the role of dietary minerals other than sodium has been less studied. However, epidemiological studies have suggested that dietary intake of magnesium and potassium may be involved in such pathogenesis. Studies of the influence of magnesium deficiency on arteriosclerosis include its effect on the initial lesion, altered metabolism of elastin, proliferation of collagen, calcification, lipid metabolism, platelet aggregation and hypertension. Magnesium and potassium metabolism are closely related and magnesium is required for maintaining the level of cellular potassium. As a consequence, magnesium and potassium deficiency frequently occur together and potassium deficiency may be an aggravating factor in pathogenesis. The development of the initial lesion in the arterial wall may be facilitated by loss of cellular magnesium and potassium. Experimental magnesium deficiency induces arterial damage, a loss of magnesium and potassium and an increase in the calcium and sodium content of the cell. Experimental models that have been used to produce cardiovascular lesions induce similar changes and losses of major intracellular cations may affect the main metabolic processes of the cell. This report summarizes the experimental evidence that magnesium deficiency may affect several different stages involved in arteriosclerosis and that potassium deficiency may exacerbate this. Magnesium deficiency results in vascular calcification. Experiments indicate that elastin is the site of the initial calcification and the metabolism of elastin is altered. This vascular lesion then brings about an increase in the collagen content of the wall. Low magnesium status could probably affect this process by slowing collagen resorption and lead to an irreversible accumulation of connective tissue. Results showing a different distribution of the various types of lipoprotein during experimental magnesium deficiency strongly suggest that lipid exchange between the vessel walls and blood can be modified. Severe magnesium deficiency in weanling rats produces a marked hypertriglyceridemia, a decrease in the percentage of cholesterol transported by HDL lipoprotein and a reduction in LCAT activity. The decreased clearance of circulatory triglycerides appears to be the major mechanism contributing to hyperlipemia. Magnesium deficiency could therefore contribute to accu

Topics: Animals; Arteriosclerosis; Blood Platelets; Calcinosis; Collagen; Diabetes Mellitus; Diet; Elastin; Humans; Hypertension; Lipid Metabolism; Lipoproteins; Magnesium; Magnesium Deficiency; Muscle, Smooth, Vascular; Potassium; Potassium Deficiency; Rats; Thrombosis

Topics: Animals; Arteriosclerosis; Blood Vessels; Elastic Tissue; Elastin; Guinea Pigs; Humans; Lipid Metabolism; Pulmonary Emphysema; Skin Diseases; Tropoelastin

Topics: Animals; Arteries; Arteriosclerosis; Collagen; Elastin; Glycoproteins; Glycosaminoglycans; Humans; Lipid Metabolism; Lipoproteins; Proteoglycans

Topics: Animals; Arteries; Arteriosclerosis; Calcium; Collagen Diseases; Cricetinae; Elastic Tissue; Elastin; Humans; Lipid Metabolism; Lung; Microscopy, Electron; Models, Chemical; Molecular Conformation; Pancreatic Elastase; Pseudoxanthoma Elasticum; Pulmonary Emphysema; Skin Diseases; Tropoelastin

Topics: Absorption; Animals; Aorta; Arteries; Arteriosclerosis; Biological Transport; Blood Physiological Phenomena; Cholesterol; Cholesterol, Dietary; Collagen; Coronary Vessels; Elastin; Haplorhini; Humans; Lymph; Macaca; Macaca fascicularis; Macaca mulatta; Postmortem Changes; Radiography; Saimiri

Topics: Adult; Aging; Amino Acids; Animals; Arteriosclerosis; Elastin; Humans; Pulmonary Emphysema; Tropoelastin

Topics: Arteries; Arteriosclerosis; Collagen; Connective Tissue; Elastin; Glycosaminoglycans; Humans; Lipid Metabolism; Muscle, Smooth, Vascular

The elastic fibers present in various connective tissues of the body are responsible for physiologic elasticity of the organs. These fibers consist of 2 distinct components, elastin and the elastic fiber microfibrils. Controlled synthesis and balanced interaction of these 2 components are essential for normal fibrillogenesis. The intracellular biosynthesis of elastin by connective tissue cells, such as smooth muscle cells, involves assembly of the polypeptide chains on the membrane-bound ribosomes, hydroxylation of some prolyl residues to hydroxyproline, and secretion of the polypeptides packaged in Golgi vacuoles. In the extracellular space the elastin molecules assemble into fiber structures which are stabilized by the synthesis of complex covalent cross-links, desmosines. Recently, aberrations in the structure or metabolism of elastin have been detected in a variety of heritable and acquired diseases affecting skin and other connective tissues. These conditions include pseudoxanthoma elasticum, cutis laxa, and elastosis perforans serpiginosa, as well as arteriosclerosis and other degenerative changes of the vascular connective tissues.

Topics: Amino Acids; Arteriosclerosis; Chemical Phenomena; Chemistry; Collagen Diseases; Connective Tissue; Contractile Proteins; Cutis Laxa; Desmosine; Ehlers-Danlos Syndrome; Elastic Tissue; Elastin; Female; Glycoproteins; Humans; Hydroxyproline; Marfan Syndrome; Menkes Kinky Hair Syndrome; Muscle Proteins; Pancreatic Elastase; Peptide Biosynthesis; Protein Precursors; Pseudoxanthoma Elasticum; X Chromosome

Thrombangiitis obliterans, a segmental, multilocal, inflammatory disease of the small and medium-sized arteries and veins, is characterized by the relatively juvenile onset of the disease, the peripheral localization of the arterial occlusions and by phlebitis saltans. Other diagnostic criteria are the absence of risk factors typical of atherosclerosis (except smoking), strictly localized occlusion on angiography, phasic clinical course, and exclusion of either collagen disease or essential thrombocytosis. A possible immunopathogenesis for the disease is increasingly favored. In our own study of 33 patients the complement factor C4 was increased in 54.6%, the antielastin antibodies were found at a titre of 1:8 in 57.1% and the immuncomplexes in 23.3%. In only 1 case was the histocompatibility antigen HLA B 12 absent. In view of these immunologic findings and also the fact that phlebitis saltans as a symptom of the disease can be suppressed by salicylates and corticosteroids, but not by anticoagulants, the following therapy is proposed: high doses of acetylsalicylic acid during the acute stage of the illness, or, if this regimen fails, a trial with corticosteroids or immunosuppressive agents.

Topics: Adult; Anti-Inflammatory Agents; Antibodies; Anticoagulants; Antigen-Antibody Complex; Arteriosclerosis; Aspirin; Complement C4; Diagnosis, Differential; Elastin; Female; Histocompatibility Antigens; Humans; Immunosuppressive Agents; Male; Middle Aged; Phlebitis; Prognosis; Risk; Smoking; Thromboangiitis Obliterans

Topics: Amino Acids; Animals; Arteries; Arteriosclerosis; Calcification, Physiologic; Cattle; Cholesterol; Connective Tissue; Elastin; Humans; Models, Chemical; Molecular Conformation; Tropoelastin

Topics: Aging; Animals; Aorta; Arteriosclerosis; Collagen; Coronary Vessels; Elastic Tissue; Elastin; Humans; Protein-Lysine 6-Oxidase; Pyridoxine; Thrombosis

Topics: Animals; Arteries; Arteriosclerosis; Calcium; Cholesterol, Dietary; Collagen; Connective Tissue; Elastin; Glycoproteins; Glycosaminoglycans; Humans

Topics: Aging; Animals; Aorta; Arteriosclerosis; Autoantibodies; Connective Tissue; Elastin; Glucosamine; Glycoproteins; Humans; Lipid Metabolism; Lysine

The changes of the arteries appearing diffusely caused by ageing as a rule favour the development of the focal arteriosclerotic changes. Already due to the increasing blood lipid level the ageing vessel is exposed to increased loads. It is more difficult for it to cope with them, since caused by ageing the cell functions of endothelium, intima and adjacent media decrease, whereas the diffundibility increases. The alterations of the mucopolysaccharide spectre in old age also render difficult the maintenance of the integrity of the arterial wall. The decrease of the distensibility of the arterial wall, partly consequence of increasing cross-linking, partly expression of senile fibrosis, is partially compensated by dilatation of the vascular tube. When arteriosclerotic beds supervene on account of solidification caused by old age additional difficulties appear. On principle the genuine changes caused by old age smooth the way for the development of arteriosclerotic changes.

Topics: Age Factors; Aged; Aging; Arteries; Arteriosclerosis; Blood Coagulation; Cholesterol; Collagen; Elastin; Glycosaminoglycans; Humans; Lipids; Lipoproteins

Topics: Aging; Amino Acid Sequence; Amino Acids; Animals; Arteriosclerosis; Calcium; Cholesterol; Copper; Cyanogen Bromide; Desmosine; Diet; Elastin; Microbial Collagenase; Models, Chemical; Molecular Weight; Protein Conformation; Swine; Tyrosine

Topics: Adolescent; Adult; Aged; Aging; Aorta; Arteries; Arteriosclerosis; Blood Pressure; Elasticity; Elastin; Female; Humans; In Vitro Techniques; Male; Middle Aged; Plethysmography, Whole Body; Pulse; Regression Analysis

Topics: Animals; Arteries; Arteriosclerosis; Autoradiography; Collagen; Disease Models, Animal; DNA; Elastin; Endothelium; Female; Glycosaminoglycans; Histocytochemistry; Humans; In Vitro Techniques; Lipid Metabolism; Polysaccharides; Proteins; Proteoglycans; Solubility; Staining and Labeling; Thymidine; Tritium; Vascular Diseases

Topics: Age Factors; Aging; Animals; Aorta; Arteries; Arteriosclerosis; Carbon Radioisotopes; Chickens; Collagen; Connective Tissue; Connective Tissue Cells; Elastin; Endothelium; Female; Glycoproteins; Glycosaminoglycans; Humans; Hydroxyproline; Hypertension; In Vitro Techniques; Lysine; Male; Microscopy, Electron; Muscle, Smooth; Proline; Rabbits; Rats; Swine

Topics: Adolescent; Adult; Age Factors; Aged; Animals; Aorta; Arteries; Arteriosclerosis; Child; Cholesterol; Collagen; Elastin; Glycosaminoglycans; Humans; Lipoproteins; Male; Middle Aged

Topics: Animals; Arteriosclerosis; Blood Platelets; Blood Vessels; Calcium; Cell Division; Cell Membrane Permeability; Collagen; Disease Models, Animal; Elastin; Endothelium; Fibrin; Glycosaminoglycans; Histocytochemistry; Humans; Lipid Metabolism; Microscopy, Electron; Necrosis; Platelet Adhesiveness

Topics: Adolescent; Animals; Aorta; Arteries; Arteriosclerosis; Calcium; Cardiovascular Diseases; Child; Collagen; Connective Tissue; Elastin; Endothelium; Female; Glycopeptides; Glycosaminoglycans; Heparin; Hexosamines; Humans; Lipids; Lipoproteins; Macromolecular Substances; Male; Vascular Diseases

Topics: Aging; Amino Acids; Animals; Aorta, Thoracic; Arteriosclerosis; Calcinosis; Cattle; Chemical Phenomena; Chemistry; Chickens; Dogs; Elastin; Extracellular Space; Hot Temperature; Humans; Macromolecular Substances

Topics: Arteries; Arteriosclerosis; Calcinosis; Calcium; Elastin; Glycoproteins; Humans; Lipid Metabolism; Macromolecular Substances; Myofibrils; Pancreatic Elastase

Topics: Animals; Arteriosclerosis; Chemical Phenomena; Chemistry; Chick Embryo; Copper; Deficiency Diseases; Elastic Tissue; Elastin; Fibroma; Guinea Pigs; Haplorhini; Histocytochemistry; Microscopy; Microscopy, Electron; Pseudoxanthoma Elasticum; Rats; Skin Neoplasms; Staining and Labeling; Swine

Topics: Adult; Animals; Arteries; Arteriosclerosis; Blood Coagulation; Chondroitin; Collagen; Elastic Tissue; Elastin; Female; Glycoproteins; Glycosaminoglycans; Heparitin Sulfate; Humans; Lipid Metabolism; Lipids; Lipoproteins; Rabbits; Staining and Labeling; Veins

Topics: Aminopropionitrile; Androgens; Animals; Arteriosclerosis; Blood Vessels; Cell Differentiation; Cholesterol; Collagen; Cyproterone; Elastin; Estrogens; Glycosaminoglycans; Humans; Hyperlipidemias; Hypertension; Muscle, Smooth; Rabbits; Rats

Topics: Aging; Allergy and Immunology; Antibody Formation; Arteriosclerosis; Autoantibodies; Autoimmune Diseases; Cell Membrane; Collagen; Connective Tissue; Corneal Transplantation; Elastin; Genes; Glycoproteins; Glycosaminoglycans; Histocompatibility Antigens; Humans; Mononuclear Phagocyte System; Solubility; Transplantation, Homologous

Topics: Aging; Animals; Aorta; Arteries; Arteriosclerosis; Cholesterol; Collagen; Coronary Disease; Coronary Vessels; Elastin; Endothelium; Glucose; Glycosaminoglycans; Humans; Lipoproteins; Lipoproteins, VLDL; Phagocytosis; Platelet Adhesiveness; Vasa Vasorum

Topics: Animals; Aorta; Arteries; Arteriosclerosis; Carbon Isotopes; Chemical Phenomena; Chemistry; Cholesterol; Cholesterol, Dietary; Connective Tissue; Elastic Tissue; Elastin; Female; Lipids; Lipoproteins; Male; Protein Precursors; Rats; Skin

Topics: Aging; Amino Acids; Aneurysm; Animals; Arteriosclerosis; Brain Diseases; Copper; Deficiency Diseases; Elastic Tissue; Elastin; Endocardial Fibroelastosis; Growth Disorders; Hair; Humans; Inflammation; Lathyrism; Marfan Syndrome; Metabolic Diseases; Respiratory Tract Diseases; Skin Diseases

Topics: Animals; Antibodies; Antigen-Antibody Complex; Antigens; Aorta; Arteriosclerosis; Autoantibodies; Cholesterol; Dietary Fats; Elastin; Epitopes; Fluorescent Antibody Technique; Freund's Adjuvant; Glycosaminoglycans; Haptens; Heparin; Humans; Hyaluronic Acid; Lipoproteins, LDL; Rabbits; Serum Sickness

Topics: Arteries; Arteriosclerosis; Cholesterol; Collagen; Elastin; Glycosaminoglycans; Humans; Hypertension; L-Lactate Dehydrogenase; Macromolecular Substances; Metabolic Diseases; Necrosis; Oxidoreductases; Sclerosis; Thrombosis; Time Factors; Vasa Vasorum

Topics: Aging; Animals; Antibody Formation; Arteriosclerosis; Calorimetry; Carbon Isotopes; Cattle; Elastin; Fluorescent Antibody Technique; gamma-Globulins; Glycoproteins; Hexosamines; Hexoses; Humans; Immunochemistry; Krypton; Molecular Biology; Neuraminic Acids; Proline; Protein Denaturation; Rabbits; Solvents; Surface Properties; Swine

Topics: Aged; Aging; Amino Acids; Aorta; Arteriosclerosis; Calcinosis; Calcium; Chemical Phenomena; Chemistry; Child; Elastic Tissue; Elastin; Fluorescence; Glycosaminoglycans; Humans; Lipids; Pulmonary Artery

Topics: Age Factors; Aminopropionitrile; Animals; Arteriosclerosis; Chemical Phenomena; Chemistry, Physical; Elastin; Lathyrism; Leucine; Molecular Weight; Protein Binding

Topics: Animals; Arteries; Arteriosclerosis; Blood Vessel Prosthesis; Collagen; Columbidae; Dogs; Elastin; Haplorhini; Humans; Lipids; Lipoproteins; Metaplasia; Monocytes; Muscle, Smooth; Rabbits; Swine

Topics: Arteriosclerosis; Chemistry Techniques, Analytical; Collagen; Elastic Tissue; Elastin; Enzyme Inhibitors; Enzyme Precursors; Pancreas; Pancreatic Elastase; Peptide Hydrolases; Research; Toxicology

Topics: Arteries; Arteriosclerosis; Atherosclerosis; Calcification, Physiologic; Collagen; Connective Tissue; Elastic Tissue; Elastin; Glycosaminoglycans; Humans; Lipids; Pathology

In some pathological states such as therosclerosis tissue destruction may be accelerated due to uncontrolled protease release of polymorphonuclear leukocytes and other events such as decreased concentration and/or the inactivation of main protease inhibitor molecules in the serum. In this study, the authors measured the elastase release of polymorphonuclear leukocytes which increased in atherosclerosis independently of the patients aged compared to healthy young subjects. These findings were similar to the response of polymorphonuclear leukocytes separated from healthy elderly subjects. Simultaneously, the main plasma proteinase inhibitors such as alpha-1-antitrypsin and alpha-2-macroglobulin in healthy and atherosclerotic subjects were determined. alpha-1-antitrypsin did not decrease significantly, whereas alpha-2-macroglobulin did in sera of atherosclerotic patients compared to age matched subjects (p < 0.05). In contrast, the activity of porcine pancreatic elastase was more effectively neutralized by the plasma obtained from healthy subjects suggesting diminished antiprotease activity of sera obtained from patients. The authors concluded that increased elastase release and decreased antiproteinase activity should be considered in atherosclerotic arterial wall damage. The similarity of the results in aged and therosclerotic subjects suggests that arteriosclerosis is an earlier aging process.

Topics: Arteriosclerosis; Elastin; Female; Humans; Leukocyte Elastase; Leukocytes; Male; Middle Aged; Pancreatic Elastase; Peptides; Protease Inhibitors

Computerized automatic-image analytical procedure was applied on dermal biopsies stained for elastin by a new procedure giving a completely white background and staining only the elastic fiber system. In arteriosclerotic hypertensive patients, a 3-4 months' treatment with 1 mg colchicine per day resulted in a significant (60-80%, p less than 0.01) increase of the dermal elastic fiber density both in the superficial papillary dermis and in the deep dermis. This result shows that the age-dependent increase of elastic fibers can be influenced by pharmacological means. The inhibition by colchicine of the synthesis and secretion of the fibroblast-derived metalloelastase-type protease could be a plausible explanation of this finding.

Topics: Adult; Aged; Arteriosclerosis; Blood Pressure; Clinical Trials as Topic; Colchicine; Elasticity; Elastin; Female; Humans; Male; Middle Aged; Skin

Topics: Amino Acids; Aorta; Arteries; Arteriosclerosis; Autoradiography; Calcinosis; Chemical Phenomena; Chemistry; Cholesterol; Clinical Trials as Topic; Elastin; Humans; Hydrolysis; In Vitro Techniques; Lipid Metabolism; Lipoproteins; Proteins; Tritium

Schimke immuno-osseous dysplasia (SIOD) is an autosomal recessive disorder caused by mutations in SMARCAL1. A frequent complication is arteriosclerosis associated with reduced elastin expression; however, the mechanism underlying the reduced elastin expression remains unknown.. Expression of transcriptional regulators of elastin (ELN) and microRNA (miRNA) regulators of ELN messenger RNA (mRNA), ELN promoter methylation, and ELN mRNA poly(A) tail length were assessed by quantitative RT-PCR, bisulfite Sanger sequencing, and the Poly(A) Tail Length Assay Kit, respectively, in unaffected developing human aortae and in an SIOD aorta.. Comparing unaffected fetal and adult aortae, ELN precursor mRNA (pre-mRNA) levels remained nearly constant, whereas mRNA levels declined by ~10(2)-fold. This corresponded with a reduction in poly(A) tail length but not with changes in the other parameters. In contrast, compared to the unaffected fetal aortae, the SIOD aorta had 18-fold less ELN pre-mRNA and 10(4)-fold less mRNA. This corresponded with increased expression of miRNA regulators and shorter ELN mRNA poly(A) tail lengths but not with altered expression of ELN transcriptional regulators or ELN promoter methylation.. Posttranscriptional mechanisms account for the reduction in ELN mRNA levels in unaffected aortae, whereas transcriptional and posttranscriptional mechanisms reduce elastin expression in SIOD aorta and predispose to arteriosclerosis.

Topics: Adolescent; Adult; Aorta; Arteriosclerosis; Case-Control Studies; Cells, Cultured; Child; Child, Preschool; DNA Methylation; Down-Regulation; Elastin; Female; Gestational Age; Humans; Immunologic Deficiency Syndromes; Male; MicroRNAs; Middle Aged; Nephrotic Syndrome; Osteochondrodysplasias; Primary Immunodeficiency Diseases; Promoter Regions, Genetic; Pulmonary Embolism; RNA Precursors; RNA Processing, Post-Transcriptional; RNA, Messenger; Transcription Factors; Transcription, Genetic

Acute aortic dissection is a life-threatening disease with a high rate of mortality. At the Institute of Legal Medicine of the Hanover Medical School, 30 cases with aortic dissections were found during autopsy and examined histologically between 2006 and 2009. The grade of medial alterations in the form of cystic medial necrosis, elastin fragmentation, fibrosis and medionecrosis were estimated semi-quantitatively. In order to assess the normal aging process, samples of the aortic wall of 25 decedents without dissecting aneurysms were analyzed histologically. This study demonstrates that there are partly quantitative differences, particularly with a statistically significant increase in cystic medial necrosis (p<0.001) and elastin fragmentation (p<0.001), between aortas from dissecting aneurysms and the normal aging aorta, which may help to identify genetically predisposed relatives of patients with a dissection of the aorta.

Topics: Adult; Aged; Aged, 80 and over; Aging; Aorta; Aortic Aneurysm; Aortic Dissection; Arteriosclerosis; Case-Control Studies; Elastin; Female; Fibrosis; Forensic Pathology; Humans; Male; Middle Aged; Necrosis; Tunica Media

Calcification and fibrosis reduce vascular compliance in arteriosclerosis. To better understand the role of osteopontin (OPN), a multifunctional protein upregulated in diabetic arteries, we evaluated contributions of OPN in male low-density lipoprotein receptor (LDLR)-/- mice fed a high-fat diet.. OPN had no impact on high-fat diet-induced hyperglycemia, dyslipidemia, or body composition. However, OPN-/-;LDLR-/- mice exhibited an altered time-course of aortic calcium accrual-reduced during initiation but increased with progression-versus OPN+/+;LDLR-/- controls. Collagen accumulation, chondroid metaplasia, and mural thickness were increased in aortas of OPN-/-;LDLR-/- mice. Aortic compliance was concomitantly reduced. Vascular reexpression of OPN (SM22-OPN transgene) reduced aortic Col2A1 and medial chondroid metaplasia but did not affect atherosclerotic calcification, Col1A1 expression, collagen accumulation, or arterial stiffness. Dosing with the proinflammatory OPN fragment SVVYGLR upregulated aortic Wnt and osteogenic gene expression, increased aortic β-catenin, and restored early-phase aortic calcification in OPN-/-;LDLR-/- mice.. OPN exerts stage-specific roles in arteriosclerosis in LDLR-/- mice. Actions phenocopied by the OPN metabolite SVVYGLR promote osteogenic calcification processes with disease initiation. OPN limits vascular chondroid metaplasia, endochondral mineralization, and collagen accumulation with progression. Complete deficiency yields a net increase in arteriosclerotic disease, reducing aortic compliance and conduit vessel function in LDLR-/- mice.

Topics: Amino Acid Sequence; Animals; Aorta; Arteriosclerosis; beta Catenin; Calcinosis; Calcium; Collagen; Diabetic Angiopathies; Elastin; Fibrosis; Male; Matrix Metalloproteinases; Mice; Mice, Knockout; Microfilament Proteins; Muscle Proteins; Osteopontin; Peptide Fragments; Promoter Regions, Genetic; Receptors, LDL; Signal Transduction; Vascular Resistance

Aspartic acid racemisation (AAR) results in an age-dependent accumulation of D: -aspartic acid in durable human proteins and can be used as a basis for age estimation. Routinely, age estimation based on AAR is performed by analysis of dentine. However, in forensic practise, teeth are not always available. Non-dental tissues for age estimation may be suitable for age estimation based on AAR if they contain durable proteins that can be purified and analysed. Elastin is such a durable protein. To clarify if purified elastin from arteries is a suitable sample for biochemical age estimation, AAR was determined in purified elastin from arteries from individuals of known age (n = 68 individuals, including n = 15 putrefied corpses), considering the influence of different stages of atherosclerosis and putrefaction on the AAR values. AAR was found to increase with age. The relationship between AAR and age was good enough to serve as basis for age estimation, but worse than known from dentinal proteins. Intravital and post-mortem degradation of elastin may have a moderate effect on the AAR values. Age estimation based on AAR in purified elastin from arteries may be a valuable additional tool in the identification of unidentified cadavers, especially in cases where other methods cannot be applied (e.g., no available teeth and body parts).

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aging; Aorta, Abdominal; Arteriosclerosis; Aspartic Acid; Child; Child, Preschool; Elastin; Forensic Pathology; Humans; Infant; Linear Models; Middle Aged; Postmortem Changes; Young Adult

Matrix remodelling plays an important role in regulating plaque stability. Cystatin C, an inhibitor of the elastin-degrading cysteine proteases of the cathepsin family, is believed to be one of the key protease inhibitors in this process. The aim of the present study was to investigate the role of leukocyte-specific cystatin C expression under conditions that favour plaque regression. Apolipoprotein E-deficient mice (apoE-/-) were given a Western-type diet 15 weeks prior transplantation with bone marrow from mice lacking cystatin C (cysC-/-) or cystatin C positive (cysC+/+) mice, in both cases apoE+/+ to create conditions favouring plaque regression. Transplantations were verified with PCR and Western analyses. Transplanted mice showed a 70% decrease in lipid content and reduction in plaque area compared to baseline ApoE-/- mice, demonstrating plaque regression due to apoE expression in macrophages. apoE-/- mice transplanted with cysC-/- bone marrow were then compared to mice transplanted with cysC+/+ bone marrow. Mice receiving cysC-/- bone marrow had a 30% larger plaque area, despite absence of significant differences in plasma cholesterol and lipid contents in plaque. Unexpectedly, mice transplanted with cystatin C-deficient bone marrow cells had increased elastin and collagen content in lesions. These observations suggest that leukocyte-specific expression of cystatin C is actively involved in matrix remodelling associated with plaque regression.

Topics: Animals; Apolipoproteins E; Arteriosclerosis; Azo Compounds; Bone Marrow Transplantation; Cholesterol; Collagen; Coloring Agents; Cystatin C; Cystatins; Dietary Fats; Elastin; Female; Lipid Metabolism; Macrophages; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Monocytes

The present study was undertaken to systematically investigate whether calcification of elastic fibers occurs in human atherosclerotic plaques. Fourteen carotid artery segments obtained by endarterectomy were examined by a combination of electron microscopy and cytochemistry. The analysis demonstrated that calcification of elastic fibers occurred in all 14 specimens. Two distinct types of calcification of elastic fibers were identified. In type I calcification, elastin itself was observed to undergo calcification and no visible structural alterations preceded the calcification. In type II of calcification, structural alteration of elastin preceded calcification of elastic fibers and included vacuolization of elastin accompanied by the accumulation of neutral lipids and unesterified cholesterol within altered elastic fibers. In type II calcification, calcified deposits were found to form in an association with unesterified cholesterol. Type II calcification was widespread throughout the plaque matrix while type I calcification occurred only in the deep portions of plaques.

Topics: Aged; Arteriosclerosis; Calcinosis; Carotid Arteries; Elastin; Female; Humans; Immunohistochemistry; Male; Microscopy, Electron; Middle Aged

It has been suggested that aortic valve sclerosis (AVS) is an atherosclerotic disease process that can proceed to aortic stenosis. The absence of reports studying an animal model of the early stages of this disease has precluded the development of preventive therapeutic strategies. A cholesterol-fed (0.25% cholesterol in chow) rabbit model of atherosclerosis that is characterized by a moderate level of hypercholesterolemia was studied to determine its efficacy as a model of early AVS. Cellular, structural and morphological changes in the aortic valves of these rabbits were studied.. Twenty rabbits were assigned randomly to four experimental groups: Group 1 received normal chow for 40 weeks; group 2 received 0.25% cholesterol-supplemented chow for 20 weeks; group 3 received 0.25% cholesterol-supplemented chow for 40 weeks; and group 4 received 0.25% cholesterol-supplemented chow for 20 weeks followed by normal chow for an additional 20 weeks. The aortas and aortic valves were analyzed using immunohistochemical and histological methods to detect cellular and structural components of the developing lesions.. All rabbits in groups 2, 3 and 4 developed atherosclerotic lesions in their aortas. Aortic valves from these animals demonstrated thickening, lipid deposition, a change in collagen content and organization, a reorganization of elastin, and the presence of both macrophage infiltrate and osteopontin.. These findings were consistent with the suggestion of a link between atherosclerosis and AVS. Results were also similar to changes reported in human sclerotic aortic valves, suggesting the suitability of this rabbit model of atherosclerosis as a model for AVS.

Topics: Animals; Aorta; Aortic Valve; Arteriosclerosis; Cholesterol, Dietary; Collagen; Diet, Atherogenic; Disease Models, Animal; Elastin; Humans; Hypercholesterolemia; Immunohistochemistry; Lipids; Macrophages; Male; Osteopontin; Phosphoproteins; Rabbits; Random Allocation; Sclerosis; Sialoglycoproteins

Epidemiological and histological evidence implicates proteinases of the matrix metalloproteinase (MMP) family in atherosclerosis and aneurysm formation. We previously indicated a role for urokinase-type plasminogen activator in atherosclerotic media destruction by proteolytic activation of MMPs. However, the role of specific MMPs, such as MMP-9 and MMP-12, in atherosclerosis remains undefined.. MMP-9- or MMP-12-deficient mice were crossed in the atherosclerosis-prone apolipoprotein E-deficient background and fed a cholesterol-rich diet. Mice were killed at 15 or 25 weeks of diet to study intermediate and advanced lesions, respectively. Loss of MMP-9 reduced atherosclerotic burden throughout the aorta and impaired macrophage infiltration and collagen deposition, while MMP-12 deficiency did not affect lesion growth. MMP-9 or MMP-12 deficiency conferred significant protection against transmedial elastin degradation and ectasia in the atherosclerotic media.. This study is the first to provide direct genetic evidence for a significant involvement of MMP-9, but not of MMP-12, in atherosclerotic plaque growth. In addition, deficiency of MMP-9 or MMP-12 protected apolipoprotein E-deficient mice against atherosclerotic media destruction and ectasia, mechanisms that implicate the involvement of these MMPs in aneurysm formation.

Topics: Animals; Aortic Diseases; Apolipoproteins E; Arteriosclerosis; Collagen; Diet, Atherogenic; Dilatation, Pathologic; Elastin; Extracellular Matrix; Female; Hypercholesterolemia; Macrophages; Matrix Metalloproteinase 12; Matrix Metalloproteinase 9; Metalloendopeptidases; Mice; Mice, Inbred C57BL; Tunica Media

Atherosclerosis is a multifactorial disease, the progression of which is modulated by several factors, including inflammation and hypercholesterolemia. The A(3) adenosine receptor (A(3)AR) has been reported to affect mast cell degranulation leading to inflammation, as well as to influence cardiovascular homeostasis. Here, we show that its deletion can also impact vascular smooth muscle cell (VSMC) proliferation in vitro. Based on these observations, we hypothesized that A(3)AR deficiency would affect atheromatous lesion development in vivo. Our results indicate that the expression of the matrix enzyme lysyl oxidase (LO) is increased while the proliferation potential of VSMC is decreased in A(3)AR-null aortas. This is in accordance with the previously reported inverse correlation between LO level and proliferation. Nevertheless, we found that A(3)-deficiency does not protect vessels against atherogenesis. This was demonstrated in mouse models of high fat diet-induced atherosclerosis and guidewire-induced femoral artery injury. We conclude that the contributions of the A(3)AR to inflammation and to modulating LO levels are not significant enough to control vascular response to injury.

Topics: Animals; Aorta; Arteriosclerosis; Base Sequence; Blotting, Western; Cells, Cultured; DNA Primers; DNA Replication; Elastin; Immunohistochemistry; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Protein-Lysine 6-Oxidase; Receptor, Adenosine A3; Up-Regulation

Elastin, an extracellular matrix protein, constitutes about 30% of the dry weight of the arteries. Elastolysis induced by inflammatory processes is active in chronic arterial diseases. However, elastogenesis in arterial diseases has received little attention. In this work we hypothesized that disordered elastogenesis is active in matrix remodeling in atheroma and abdominal aortic aneurysm (AAA).. Human AAA and atheroma have 4- to 6-fold more tropoelastin protein than nondiseased arteries. The smooth muscle cell-containing media and fibrous cap of atherosclerotic arteries contain ordered mature elastin, whereas macrophage (MPhi)-rich regions often have disorganized elastic fibers. Surprisingly, in addition to smooth muscle cells, MPhis in diseased arteries also produce the elastin precursor tropoelastin, as shown by double immunostaining, in situ hybridization, and reverse transcription-polymerase chain reaction for tropoelastin mRNA. Cultured monocyte-derived MPhis can express the elastin gene. AAA have 9-fold but atheroma only 1.6-fold lower levels of desmosine, a marker for mature cross-linked elastin, than normal arteries.. This study demonstrates ongoing but often ineffective elastogenesis in arterial disease and establishes human macrophages as a novel source for this important matrix protein. These results have considerable import for understanding mechanisms of extracellular matrix remodeling in arterial diseases.

Topics: Aorta; Aortic Aneurysm, Abdominal; Arteriosclerosis; Cells, Cultured; Desmosine; Elastin; Extracellular Matrix Proteins; Humans; In Situ Hybridization; Macrophages; RNA, Messenger; Tropoelastin

Human atherosclerotic lesions overexpress the lysosomal cysteine protease cathepsin S (Cat S), one of the most potent mammalian elastases known. In contrast, atheromata have low levels of the endogenous Cat S inhibitor cystatin C compared with normal arteries, suggesting involvement of this protease in atherogenesis. The present study tested this hypothesis directly by crossing Cat S-deficient (CatS(-/-)) mice with LDL receptor-deficient (LDLR(-/-)) mice that develop atherosclerosis on a high-cholesterol diet. Compared with LDLR(-/-) mice, double-knockout mice (CatS(-/-)LDLR(-/-)) developed significantly less atherosclerosis, as indicated by plaque size (plaque area and intimal thickening) and stage of development. These mice also had markedly reduced content of intimal macrophages, lipids, smooth muscle cells, collagen, CD4(+) T lymphocytes, and levels of IFN-gamma. CatS(-/-)LDLR(-/-) monocytes showed impaired subendothelial basement membrane transmigration, and aortas from CatS(-/-)LDLR(-/-) mice had preserved elastic laminae. These findings establish a pivotal role for Cat S in atherogenesis.

Topics: Animals; Arteriosclerosis; Cathepsins; Cell Movement; Collagen; Elastin; Leukocytes; Macrophages; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Rabbits; Receptors, LDL

Vascular smooth muscle cell (SMC) proliferation and migration are important events in the development of atherosclerosis. The low-density lipoprotein receptor-related protein (LRP1) mediates suppression of SMC migration induced by platelet-derived growth factor (PDGF). Here we show that LRP1 forms a complex with the PDGF receptor (PDGFR). Inactivation of LRP1 in vascular SMCs of mice causes PDGFR overexpression and abnormal activation of PDGFR signaling, resulting in disruption of the elastic layer, SMC proliferation, aneurysm formation, and marked susceptibility to cholesterol-induced atherosclerosis. The development of these abnormalities was reduced by treatment with Gleevec, an inhibitor of PDGF signaling. Thus, LRP1 has a pivotal role in protecting vascular wall integrity and preventing atherosclerosis by controlling PDGFR activation.

Topics: Animals; Aorta; Arteriosclerosis; Becaplermin; Benzamides; Cattle; Cell Division; Cell Line; Cholesterol, Dietary; Diet, Atherogenic; Elastin; Enzyme Inhibitors; Imatinib Mesylate; Ligands; Low Density Lipoprotein Receptor-Related Protein-1; Mesenteric Arteries; Mice; Mice, Knockout; Mice, Transgenic; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Phosphorylation; Piperazines; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Pyrimidines; Receptor, Platelet-Derived Growth Factor beta; Signal Transduction

Cardiovascular diseases, such as atherosclerosis and hypertension, are associated with arterial stiffening. Previous studies showed that ANG II exacerbated atherosclerosis and induced hypertension and aneurysm formation in apolipoprotein E-deficient (apoE-KO) mice. The aim of the present study was to examine the effects of chronic treatment of ANG II on the arterial elastic properties in apoE-KO mice. We hypothesized that ANG II will injure the arterial wall resulting in increased arterial stiffening. Male apoE-KO mice were infused with either ANG II (1.44 mg. kg(-1). day(-1)) or vehicle (PBS) for 30 days. ANG II treatment accelerated atherosclerosis in the carotid artery by sixfold (P < 0.001) and increased blood pressure by 30% (P < 0.05). Additionally, our data demonstrated that ANG II increased arterial stiffening using both in vivo and in vitro methods. ANG II significantly increased pulse wave velocity by 36% (P < 0.01) and decreased arterial elasticity as demonstrated by a more than 900% increase in maximal stiffening (high strain Young's modulus) compared with vehicle (P < 0.05). These functional changes were correlated with morphological and biochemical changes as demonstrated by an increase in collagen content (60%), a decrease in elastin content (74%), and breaks in the internal elastic lamina in the aortic wall. In addition, endothelium-independent vasorelaxation to sodium nitroprusside was impaired in the aortic rings of ANG II-treated mice compared with vehicle. Thus, the present data indicate that ANG II injures the artery wall in multiple ways and arterial stiffening may be a common outcome of ANG II-induced arterial damage.

Topics: Acetylcholine; Angiotensin II; Animals; Aorta; Aortic Aneurysm, Abdominal; Apolipoproteins E; Arteriosclerosis; Blood Pressure; Carotid Arteries; Collagen; Drug Administration Schedule; Elasticity; Elastin; Endothelium, Vascular; Male; Mice; Mice, Knockout; Nitroprusside

To measure serum concentrations of elastin-derived peptides (S-EDP) in patients with aneurysmal, occlusive and ulcerative manifestations of atherosclerotic disease.. S-EDP concentrations were measured by a competitive enzyme-linked immunosorbent assay in 10 patients with infrarenal aneurysms 5cm in diameter (AAA), 10 patients with distal aortic occlusive disease (AOD), 10 patients with symptomatic carotid stenosis (>or=70%) and plaque ulceration (SCS) and a control group of 10 patients with no similar specific manifestations of atherosclerotic disease (NAM).. S-EDP concentrations (median, range) were significantly higher in patients with AAA (42ng/ml, 35-52, p<0.001) and SCS (49ng/ml, 37-60, p<0.001) but not AOD (28ng/ml, 22-38, p=0.240) compared to NAM (26ng/ml, 19-36) patients.. Increased concentrations of S-EDP were associated with aneurysmal and ulcerative, but not occlusive, manifestations of atherosclerosis.

Topics: Aged; Aged, 80 and over; Analysis of Variance; Aortic Aneurysm, Abdominal; Aortic Diseases; Arterial Occlusive Diseases; Arteriosclerosis; Carotid Stenosis; Elastin; Enzyme-Linked Immunosorbent Assay; Female; Humans; Male; Middle Aged; Peptides; Pulmonary Disease, Chronic Obstructive; Smoking; Statistics, Nonparametric

Glycoxidation and lipid peroxidation products accumulate in collagen of various tissues in haemodialysis patients with end-stage renal disease (ESRD). The purpose of this study was to test the hypothesis that increased glycoxidation and lipid peroxidation of aortic elastin is implicated in the cardiovascular complications, particularly atherosclerosis, of chronic haemodialysis patients.. Post-mortem aortic samples were obtained from 16 deceased subjects, including chronic haemodialysis patients (group 1 n=6, age 64.7+/-11.4 years) and control subjects (group 2 n=10, age 61.1+/-10.4 years). The samples were divided into three vessel wall sites: atherosclerotic intima, lesion-free intima, and media. They were sequentially treated with 0.01 M phosphate-buffered saline, collagenase, and elastase to obtain three fractions, namely soluble (SF), collagen (CF), and elastin (EF) fractions, respectively. Using spectrophotofluorometry, the pentosidine- and malondialdehyde (MDA)-linked fluorescence of these fractions was measured at wavelengths 335/385 and 390/460 (excitation/emission), respectively.. Samples from haemodialysis patients (group 1) exhibited a significant increase in both pentosidine- and MDA-linked fluorescence of EF in atherosclerotic intima, lesion-free intima, and media samples, compared with samples from control subjects (group 2). In group 1, the levels of pentosidine- and MDA-linked fluorescence of EF were highest in atherosclerotic intima among the three aortic sites. Interestingly, in both groups, the levels of pentosidine- and MDA-linked fluorescence of EF were significantly higher than those of CF in all aortic sites. There was a strong correlation between the levels of pentosidine- and MDA-linked fluorescence in CF and EF for all aortic sites. In group 1, the pentosidine- and MDA-linked fluorescence levels of EF correlated significantly with the duration of haemodialysis in lesion-free intima and media.. Our study provides the first biochemical evidence for a close link between aortic elastin glycoxidation and lipid peroxidation. In addition, we demonstrated high levels of these products in the aortic elastin of haemodialysis patients with ESRD. Our findings support the hypothesis that modification of aortic elastin by glycoxidation and lipid peroxidation may contribute to the development of vascular complications, particularly atherosclerosis, in patients with end-stage renal failure.

Topics: Arteriosclerosis; C-Reactive Protein; Elastin; Fluorescence; Glycosylation; Humans; Kidney Failure, Chronic; Lipid Peroxidation; Malondialdehyde; Oxidation-Reduction; Renal Dialysis

Nitric oxide (NO), an endothelium-dependent relaxing factor, regulates relaxation, proliferation, and migration of smooth muscle cells (SMCs) and most likely attenuates developing vascular disease such as atherosclerosis. We investigated whether or not NO is associated with regulation of aortic elasticity. S-Nitrosoglutathione (GSNO), a NO donor, stimulated tropoelastin synthesis in cultured SMCs during both the quiescent and proliferating phases. The stimulation of tropoelastin synthesis was dose-dependent within 1-100 nM. Maximum stimulation was detected by treatment with 100 nM GSNO for 24 h. 8-Bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP), an exogenous cyclic GMP analog, also upregulated tropoelastin synthesis. Tropoelastin and lysyl oxidase mRNA expression, as assessed by Northern blot analysis, was also stimulated by GSNO. Administration of KT5823, a cyclic GMP-dependent protein kinase inhibitor, inhibited the GSNO-induced tropoelastin synthesis. These results indicate that the stimulatory effects of GSNO are due to cyclic GMP dependent protein kinase (PKG) activation by NO. In conclusion, NO seems to enhance aortic elasticity via tropoelastin and lysyl oxidase upregulation.

Topics: Animals; Aorta; Arteriosclerosis; Cell Division; Chick Embryo; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Elastin; Glutathione; Muscle, Smooth, Vascular; Nitric Oxide; Nitroso Compounds; Protein-Lysine 6-Oxidase; RNA, Messenger; S-Nitrosoglutathione; Tropoelastin

The time-resolved fluorescence spectra of the main arterial fluorescent compounds were retrieved using a new algorithm based on the Laguerre expansion of kernels technique. Samples of elastin, collagen and cholesterol were excited with a pulsed nitrogen laser and the emission was measured at 29 discrete wavelengths between 370 and 510 nm. The expansion of the fluorescence impulse response function on the Laguerre basis of functions was optimized to reproduce the observed fluorescence emission. Collagen lifetime (5.3 ns at 390 nm) was substantially larger than that of elastin (2.3 ns) and cholesterol (1.3 ns). Two decay components were identified in the emission decay of the compounds. For collagen, the decay components were markedly wavelength dependent and hydration dependent such that the emission decay became shorter at higher emission wavelengths and with hydration. The decay characteristics of elastin and cholesterol were relatively unchanged with wavelength and with hydration. The observed variations in the time-resolved spectra of elastin, collagen and cholesterol were consistent with the existence of several fluorophores with different emission characteristics. Because the compounds are present in different proportions in healthy and atherosclerotic arterial walls, characteristic differences in their time-resolved emission spectra could be exploited to assess optically the severity of atherosclerotic lesions.

Topics: Arteries; Arteriosclerosis; Cholesterol; Collagen; Elastin; Humans; Image Processing, Computer-Assisted; Spectrometry, Fluorescence; Time Factors

Topics: Aorta; Arteriosclerosis; Elastin; Humans; Lipoproteins, LDL; Tunica Intima; Tunica Media

Fluorescence emission analysis (FEA) has proven to be very sensitive for the detection of elastin, collagen and lipids, which are recognized as the major sources of autofluorescence in vascular tissues. FEA has also been reported to detect venous thromboemboli. In this paper we have tested the hypothesis that FEA can reproducibly detect in vivo and in vitro triggered plaque disruption and thrombosis in a rabbit model. Fluorescence emission (FE) spectra, recorded in vivo, detected Russell's viper venom (RVV)-induced transformation of atherosclerotic plaque. FE intensity at 410-490 nm 4 weeks after angioplasty was significantly lower (P < 0.0033 by analysis of variance) in RVV-treated rabbits when compared to control animals with stable plaque. FE spectral profile analyses also demonstrated a significant change in curve shape as demonstrated by polynomial regression analysis (R2 from 0.980 to 0.997). We have also demonstrated an excellent correlation between changes in FE intensity and the structural characteristics detected at different stages of "unstable atherosclerotic plaque" development using multiple regression analysis (R2 = 0.989). Thus, FEA applied in vivo is a sensitive and highly informative diagnostic technique for detection of triggered atherosclerotic plaque disruption and related structural changes, associated with plaque transformation, in a rabbit model.

Topics: Angioplasty, Balloon; Animals; Arteriosclerosis; Collagen; Daboia; Disease Models, Animal; Elastin; Fluorescence; Rabbits; Spectrometry, Fluorescence; Thrombosis; Viper Venoms

Leukocyte infiltration and serine elastase activity lead to smooth muscle cell proliferation in association with posttransplant coronary arteriopathy and may also be involved in vein graft neointimal formation. A number of therapies have targeted cellular proliferation, but the inhibition of serine elastase-mediated extracellular matrix remodeling has not been investigated as a potential strategy to prevent neointimal formation and subsequent atherosclerotic degeneration in vein grafts.. We studied jugular vein grafts 48 hours after interposition into the carotid arteries of rabbits and demonstrated inflammatory cell infiltration and elevated serine elastase activity, a stimulus for matrix remodeling and deposition of elastin. Therefore, elastolytic activity in vein grafts was targeted through transient expression of the selective serine elastase inhibitor elafin with hemagglutinating virus of Japan liposome-mediated gene transfer. Elafin transfection reduced inflammation by 60% at 48 hours and neointimal formation by approximately 50% at 4 weeks after implantation. At 3 months, a 74% decrease in neointimal elastin deposition correlated with protection against cholesterol-induced macrophage infiltration and lipid accumulation, which were both reduced by approximately 50% in elafin-transfected grafts relative to controls.. Gene transfer of the selective serine elastase inhibitor elafin in vein grafts is effective in reducing the early inflammatory response. Although transient expression of elafin delays neointimal formation, it is also sufficient to cause an alteration in elastin content of the extracellular matrix, making it relatively resistant to atherosclerotic degeneration.

Topics: Animals; Arteriosclerosis; Carotid Arteries; Disease Models, Animal; Elastin; Extracellular Matrix; Gene Transfer Techniques; Graft Occlusion, Vascular; Immunohistochemistry; Jugular Veins; Liposomes; Proteinase Inhibitory Proteins, Secretory; Proteins; Rabbits; Respirovirus; Serine Proteinase Inhibitors; Transfection; Tunica Intima

Structure and content of atherosclerotic plaque varies between patients and may be indicative of their risk for embolisation. This study aimed to construct parametric images of B-scan texture and assess their potential for predicting plaque morphology. Sequential transverse in vitro scans of 10 carotid plaques, excised during endarterectomy, were compared with macrohistology maps of plaque content. Multidiscriminant analysis combined the output of 157 statistical and textural algorithms into five separate texture classes, displayed as ultrasound (US) texture classification images (UTCI). Visual comparison between corresponding UTCI and histology maps found the five texture classes matched with the location of fibrin, elastin, calcium, haemorrhage or lipid. However, histology preparation removes calcium and lipid and, so, can affect the structural integrity of atherosclerotic plaques. Soft tissue regions smaller than the UTCI kernel, (0.87 mm x 0.85 mm x 3.9 mm), such as blood clots, are also difficult to detect by UTCI. These factors demonstrate limitations in the use of histology as a "gold standard" for US tissue characterisation.

Topics: Arteriosclerosis; Calcium; Carotid Arteries; Carotid Stenosis; Elastin; Endarterectomy, Carotid; Fibrin; Hemorrhage; Humans; Image Processing, Computer-Assisted; In Vitro Techniques; Lipids; Ultrasonography

To investigate whether there are alterations of elastin fibres in the arterial intima at the pre-atherosclerotic stage, grossly normal areas of human thoracic aorta were taken soon after death from 13 healthy trauma victims whose ages ranged from 16 to 40 years. Two areas were compared: atherosclerosis-prone (AP) areas localised to the dorsal aspect of the aorta along the rows of intercostal branch origins, and atherosclerosis-resistant (AR) areas from the ventral aorta. Electron microscopic analysis combined with cytochemical staining was applied. Unesterified cholesterol was identified using the filipin-staining technique while neutral lipids were visualised by the OTO-technique. Intimal features were studied by combining the filipin-staining and the OTO-technique. Electron microscopical examination showed that in both AR and AP areas, some elastin fibres in the intima were vacuolised. Unesterified cholesterol was found to be predominantly localised in the musculoelastic layer, in particular, inside the vacuolised elastin fibres. This localisation was seen in all 13 AP areas studied in contrast to the AR areas where it was observed in only four of 13 aortas studied (P < 0.0005, chi2-test). Accumulation of neutral lipids inside vacuolised elastin fibres was found in five out of 13 AP areas but was not observed in any of the AR areas (P=0.01, chi2). A combination of the filipin-staining and OTO-techniques showed that some deposits of neutral lipids and unesterified cholesterol within vacuolised elastin fibres were independently located from each other, but more frequently, neutral lipids were co-located with unesterified cholesterol. The present observations indicate a difference between AP and AR intimal areas which, in particular, relates to the structure of elastin fibres in the musculoelastic layer. The observations suggest that alterations of the extracellular matrix are involved in the trapping and retention of cholesterol and neutral lipids within the intima at an early stage in the development of atherosclerotic lesions.

Topics: Adolescent; Adult; Aorta, Thoracic; Arteriosclerosis; Cholesterol; Elastin; Humans; Lipids; Tunica Intima

The comparative effects of vitamin K2 and vitamin E on aortic calcium (Ca) and inorganic phosphorus (P) levels in the aorta and the elastin fraction (fr.) were investigated in male rats after experimental arteriosclerosis was induced by vitamin D2 with atherogenic diet. Both vitamin K2 (100 mg/kg b.w.) and vitamin E (40 mg/kg b.w.) inhibited the increase of Ca and P in the aorta and the elastin fr. from the arteriosclerotic rats. Vitamin K2 (50 mg/kg b.w.) also suppressed the deposition of Ca and P in the aorta, but there was no change due to vitamin K3 or geranylgeraniol (side chain of vitamin K2) administration. Both vitamin K2 and vitamin E showed lipid radical scavenging activity in the in vitro experiment. However, neither vitamin K3 nor geranylgeraniol exhibited anti-arteriosclerotic or radical scavenging activity under the above experimental conditions. It is suggested that vitamin K2 and vitamin E promoted an antiarteriosclerotic effect by radical scavenging activity. These actions of vitamin K2 are required in the structure of 2-methylnaphtoquinone and its side chain (geranylgeraniol).

Topics: Animals; Aorta; Arteriosclerosis; Calcium; Diet, Atherogenic; Elastin; Ergocalciferols; Free Radical Scavengers; Male; Naphthoquinones; Phosphorus; Rats; Rats, Sprague-Dawley; Structure-Activity Relationship; Vitamin E; Vitamin K; Vitamin K 3

A hallmark of vascular lesions is the phenotypic modulation of vascular smooth muscle cells (VSMCs) from a quiescent, contractile state to a more primitive, proliferative phenotype with a more fetal pattern of gene expression. Using subtraction hybridization to identify genes that may regulate this transition, we cloned a novel gene named EVEC, an acronym for its expression in the embryonic vasculature and the presence of Ca2+ binding epidermal growth factor-like repeats contained in the predicted protein structure. Although these repeats are characteristic of the extracellular matrix proteins, fibrillin, fibulin, and the latent transforming growth factor-beta binding proteins, EVEC most closely resembles the H411 and T16/S1-5 gene products, the latter of which are believed to regulate DNA synthesis in quiescent fibroblasts. Using in situ hybridization, we demonstrated that EVEC is expressed predominantly in the VSMCs of developing arteries in E11.5 through E16.5 mouse embryos. Lower levels of expression are also observed in endothelial cells, perichondrium, intestine, and mesenchyme of the face and kidney. EVEC mRNA expression is dramatically downregulated in adult arteries, except in the uterus, where cyclic angiogenesis continues; however, EVEC expression is reactivated in 2 independent rodent models of vascular injury. EVEC mRNA is observed in cellular elements of atherosclerotic plaques of LDL receptor-deficient, human apolipoprotein B transgenic mice and in VSMCs of the media and neointima of balloon-injured rat carotid arteries. These data suggest that EVEC may play an important role in the regulation of vascular growth and maturation during development and in lesions of injured vessels.

Topics: Age Factors; Animals; Arteriosclerosis; Blotting, Northern; Cells, Cultured; Cloning, Molecular; COS Cells; Cytoplasmic Granules; Elastin; Epidermal Growth Factor; Extracellular Matrix Proteins; Fetus; Gene Expression Regulation, Developmental; In Situ Hybridization; Mice; Microsomes; Molecular Sequence Data; Muscle, Smooth, Vascular; Phenotype; Rats; Recombinant Proteins; Repetitive Sequences, Nucleic Acid; RNA, Messenger; Sequence Homology, Amino Acid; Tunica Intima; Up-Regulation

To study the photobleaching of the main fluorescent compounds of the arterial wall, we repeatedly measured the time-resolved fluorescence of elastin, collagen and cholesterol during 560 s of excitation with nitrogen laser pulses. Three fluence rate levels were used: 0.72, 7.25 and 21.75 microW/mm2. The irradiation-related changes of the fluorescence intensity and of the time-resolved fluorescence decay constants were characterized for the emission at 390, 430 and 470 nm. The fluorescence intensity at 390 nm decreased by 25-35% when the fluence delivered was 4 mJ/mm2, a common value in fluorescence studies of the arterial wall. Cholesterol fluorescence photobleached the most, and elastin fluorescence photobleached the least. Photobleaching was most intense at 390 nm and least intense at 470 nm such that the emission spectra of the three compounds were markedly distorted by photobleaching. The time-resolved decay constants and the fluorescence lifetime were not altered by irradiation when the fluence was below 4 mJ/mm2. The spectral distortions associated with photobleaching complicate the interpretation of arterial wall fluorescence in terms of tissue content in elastin, collagen and cholesterol. Use of the time-dependent features of the emission that are not altered by photobleaching should increase the accuracy of arterial wall analysis by fluorescence spectroscopy.

Topics: Animals; Arteries; Arteriosclerosis; Cattle; Cholesterol; Collagen; Elastin; Fluorescent Dyes; In Vitro Techniques; Photochemistry; Spectrometry, Fluorescence; Ultraviolet Rays

The broad-spectrum MMP inhibitor CGS 27023A was tested to determine its potential as a therapy for atherosclerosis, aneurysm, and restenosis. LDL receptor-deficient (LDLr -/-) mice fed a high-fat, cholic acid-enriched diet for 16 weeks developed advanced aortic atherosclerosis with destruction of elastic lamina and ectasia in the media underlying complex plaques. Lesion formation correlated with a 4.6- to 21.7-fold increase in MMP-3, -12, and -13 expression. Treatment with CGS 27023A (p.o., b.i.d. at 50 mg/kg) had no effect on the extent of aortic atherosclerosis (36 +/- 4% versus 30 +/- 2% in controls), but both aortic medial elastin destruction and ectasia grade were significantly reduced (38% and 36%, respectively, p < 0.05). In the rat ballooned-carotid-artery model, CGS 27023A (12.5 mg/kg/day via osmotic minipump) reduced smooth muscle cell migration at 4 days by 83% (p < 0.001). Intimal lesions were reduced by 85% at 7 days (p < 0.001), but intimal smooth muscle proliferation was unaffected, and inhibitory efficacy was lost with time. At 12 days, intimal lesion reduction was less potent (52%, p < 0.01). At 3 and 6 weeks, reductions of 11% and 4%, respectively, were not significant. This demonstrates that it is essential to include late time points when the ballooned-carotid-artery model is employed to ensure that lesion size does not "catch up" when a compound solely inhibits smooth muscle cell migration. In summary, MMP inhibitor therapy delayed but did not prevent intimal lesions, thereby demonstrating little promise to prevent restenosis. In contrast, MMP inhibitor therapy may prove useful to retard progression of aneurysm.

Topics: Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Arteriosclerosis; Carotid Arteries; Carotid Artery Injuries; Catheterization; Cell Movement; Collagenases; Elastin; Hydroxamic Acids; Male; Matrix Metalloproteinase 12; Matrix Metalloproteinase 13; Matrix Metalloproteinase 3; Metalloendopeptidases; Mice; Mice, Knockout; Protease Inhibitors; Pyrazines; Rats; Rats, Sprague-Dawley; Receptors, LDL; Recurrence; Sulfonamides; Transcription, Genetic

The intimal hyperplasia hypothesis that equates lumen narrowing after arterial injury with intimal mass has recently been challenged. Evidence has emerged to suggest that lumen narrowing is caused in large part by changes in artery wall geometry rather than intimal mass per se. We have begun to explore this hypothesis in a unique nonhuman primate model of atherosclerosis.. Monkeys who were fed an atherogenic diet for 3 to 5 years underwent experimental angioplasty of the left iliac artery. The contralateral iliac artery served as an intraanimal control. Arteries were removed 2, 4, 7, 14, 28, or 112 days later for analysis (6 or 13 per time point). Angioplasty dilated arteries by fracturing atheroma and stretching or tearing the media. Cross-sections of injured arteries were analyzed for expression of extracellular matrix components and cell surface integrins that are important in wound healing. Antibodies, riboprobes, or histochemical stains specific for fibrin, hyaluronan, versican (chondroitin sulfate-containing proteoglycan), procollagen-I, elastin, and the alpha 2 beta 1 and alpha V beta 3 integrins were used.. A thin mural thrombus was seen at sites of denudation and plaque fracture (days 2 to 7). This provisional matrix was invaded by leukocytes (days 2 to 4) and alpha-actin-positive smooth muscle cells (SMCs; days 4 to 7). Thrombus was replaced by SMCs expressing hyaluronan and the associated versican proteoglycans (day 14). Versican was expressed throughout the neointima as it enlarged (day 28), but expression later subsided (day 112). Procollagen-I expression initially increased in the adventitia (day 4) and then in the forming neointima (day 14). Procollagen-I expression was found to persist within the adventitia and in the neointima in SMCs nearest the lumen (days 28 to 112). Elastin staining was prominent within the mature neointima (day 112) but not at earlier time points. Integrin expression also increased within the injured artery wall. alpha v beta 3 staining (fibrin[ogen] receptor) increased in the injured media (days 2 to 7) and was then seen throughout the early neointima (day 7). Low level expression of alpha V beta 3 subsequently persisted within the forming neointima (day 28). alpha 2 beta 1 (collagen receptor) expression increased in the neointima in SMCs nearest the lumen (day 28).. Lumen narrowing after angioplasty in this model of atherosclerosis is caused largely by decreased artery wall diameter. The pattern of matrix and integrin expression within the injured artery wall is in many ways analogous to that of healing wounds. These observations suggest that tissue contraction may play a role in lumen narrowing at sites of arterial reconstruction. Strategies to inhibit wound contraction may prove effective in preventing restenosis.

Topics: Angioplasty, Balloon; Animals; Arteriosclerosis; Chondroitin Sulfate Proteoglycans; Elastin; Extracellular Matrix Proteins; Female; Hyaluronic Acid; Iliac Artery; Immunohistochemistry; In Situ Hybridization; Integrins; Lectins, C-Type; Macaca fascicularis; Procollagen; Thrombosis; Tunica Intima; Versicans; Wound Healing

The objective of this study was to determine the arterial responses to plasma lipid lowering alone or in combination with (1) estrogen replacement therapy or (2) hormone replacement therapy in surgically postmenopausal female monkeys with preexisting atherosclerosis. Eighty-eight female cynomolgus macaques were ovariectomized, fed an atherogenic diet for 24 months, and then assigned by randomized stratification into 4 groups. One group (baseline, n=20) was necropsied at the end of the atherogenic diet period; the remaining 3 groups were fed a plasma lipid-lowering diet (regression) for 30 months. These regression groups were control (diet only), CEE (receiving conjugated equine estrogens alone), and CEE+MPA (receiving CEE and continuous medroxyprogesterone acetate). A previous report described coronary artery functional and histological results; the present report describes biochemical and histological results from the abdominal aorta. Aortic plaque size was not different between groups, similar to previous findings in the coronary arteries. Aortic cholesterol content (milligrams per gram lipid-free dry weight) was lower in the regression groups compared with baseline, both for free cholesterol (mean, control=19.1, CEE=15.7, CEE+MPA=14.4, and baseline=32.7; P<0.001) and for esterified cholesterol (mean, control=18.9, CEE=15.4, CEE+MPA=14.2, and baseline=58.7; P<0.001). This cholesterol efflux could lead to increased plaque stability without changing the physical size of the lesion. Alterations in aortic connective tissue composition were observed in the regression groups. When expressed as a percentage of the lipid-free tissue weight, the aortic elastin content of the control (mean=14.9) and the CEE+MPA (mean=14.0) groups was lower than that of the baseline group (mean=19.0), which was not different from that of the CEE group (mean=15.8). Aortic collagen content, as estimated by hydroxyproline content per milligram of lipid-free tissue, was higher in the control group (mean=67.4) and the CEE+MPA group (mean=66.1) than in the baseline group (mean=56.2; P<0.05). Collagen content of the CEE group (mean=58.9) was not different from that of the baseline group. When the regression groups were considered separately, the aortic collagen content of the CEE group was lower than that of the control group (P<0.05) and tended to be lower than that of the CEE+MPA group (P=0.10), suggesting that CEE therapy (but not CEE+MPA) inhibits potentially detrimental connective t

Topics: Animals; Aorta; Arteriosclerosis; Cholesterol; Cholesterol, Dietary; Collagen; Connective Tissue; Dietary Fats; Drug Interactions; Elastin; Estrogen Replacement Therapy; Estrogens, Conjugated (USP); Female; Horses; Lipids; Macaca fascicularis; Medroxyprogesterone Acetate; Minerals; Ovariectomy

The structure of medial elastin determines arterial function and affects wall mechanical properties. The aim of this study was to (1) characterize the structure of elastin in terms of textural features, (2) relate structural parameters to total number of cardiac cycles (TC), and (3) determine the contribution of medial elastin to lumen mechanical stress. Images of pressure-fixed aortic sections stained for elastin were obtained from specimens collected postmortem from 35 animals of different species with a wide range of age, heart rate, and TC and divided into 2 groups: TClow=3.69+/-0.38x10(8) (n=17) and TChigh=15.8+/-2.38x10(8) (n=18) (P<0.001). A directional fractal curve was generated for each image, and image texture was characterized by directional fractal curve parameters. Elastin volume fraction and interlamellar distance were obtained by image analysis. Wall stress distribution was determined from a finite element model of the arterial wall with multiple layers simulating elastin lamellae. DFC amplitude was related to elastin volume fraction. Increased TC (TClow versus TChigh) was associated with lower directional fractal curve amplitude (0.23+/-0.02 versus 0.14+/-0.02; P<0.001), reduced elastin volume fraction (36.5+2.6% versus 25.7+2.1%; P<0.01), and increased interlamellar distance (8.5+/-0.5 versus 11.5+/-1.0 microm; P<0.05). Loss of medial elastic function increased pressure-dependent maximal circumferential stress. Structural alterations of medial elastin, quantified by fractal parameters, are associated with cumulative effects of repeated pulsations due to the combined contribution of age and heart rate. Loss of medial functional elasticity increases luminal wall stress, increasing the possibility of endothelial damage and predisposition to atherosclerosis.

Topics: Age Factors; Animals; Aorta, Thoracic; Arteries; Arteriosclerosis; Data Interpretation, Statistical; Elasticity; Elastin; Endothelium, Vascular; Fractals; Heart Rate; Histological Techniques; Stress, Mechanical; Tunica Media

Formation of the atherosclerotic intima must involve altered metabolism of the elastin-rich arterial extracellular matrix. Proteases potentially involved in these processes remain unclear. This study examined the expression of the potent elastases cathepsins S and K in human atheroma. Normal arteries contained little or no cathepsin K or S. In contrast, macrophages in atheroma contained abundant immunoreactive cathepsins K and S. Intimal smooth muscle cells (SMC), especially cells appearing to traverse the internal elastic laminae, also contained these enzymes. Extracts of atheromatous tissues had approximately twofold greater elastase-specific activity than extracts of uninvolved arteries, mostly due to cysteine proteases. Cultured human SMC displayed no immunoreactive cathepsins K and S and exhibited little or no elastolytic activity when incubated with insoluble elastin. SMC stimulated with the atheroma-associated cytokines IL-1beta or IFN-gamma secreted active cathepsin S and degraded substantial insoluble elastin (15-20 microg/10(6) cells/24 h). A selective inhibitor of cathepsin S blocked > 80% of this elastolytic activity. The presence of cathepsins K and S at sites of vascular matrix remodeling and the ability of SMC and macrophages to use these enzymes to degrade elastin supports a role for elastolytic cathepsins in vessel wall remodeling and identifies novel therapeutic targets in regulating plaque stability.

Topics: Arteriosclerosis; Carotid Stenosis; Cathepsin K; Cathepsins; Cells, Cultured; Coronary Disease; Elastin; Enzyme Induction; Humans; Interferon-gamma; Muscle, Smooth, Vascular; RNA, Messenger; Tunica Intima

Calcification has been examined in 250 samples of atherosclerotic lesions (types II to VI) of human carotid arteries using von Kossa and haematoxylin staining. Early calcification described as 'stippling' was first noted in stage III specimens, with intermediate and solid calcifications becoming increasingly prominent within advanced plaques, especially stages Vb and VI. Although the relative frequencies of stippling, intermediate and large calcified deposits varied between plaques of the same stage, the prevalent sites of calcification were recognized as the deeper regions of the intima and the atheroma. Immunolocalization and histochemical techniques were used to identify the associations of mast cells (MCs), macrophages, smooth muscle cells (SMCs), and elastin with the different stages of calcification. Early, dispersed stippling was commonly associated with local accumulations of macrophages (HAM56 and CD68-positive), MCs and extracellular MC tryptase, the presence of immunoreactive elastin, but the relative absence of SMCs. Intermediate stages of calcification described as 'morula' deposits were also associated with local increases in the numbers of macrophages and MCs. Larger calcified deposits, even within the same plaque specimen, showed no regular pattern of cellular or elastin associations. However, in the vast majority of specimens, macrophages represented the predominant cell type associated with different phases of calcification. By contrast, the calcification less frequently observed in the media beneath advanced plaques was commonly associated with SMCs and elastin; only rarely were macrophages or MCs present. These studies are the first to demonstrate that macrophages, MCs, and extracellular tryptase frequently occupy micro-environmental loci showing the first stages of calcification within the atherosclerotic plaque; similar associations with more advanced mineral deposits are discussed in relation to plaque rupture.

Topics: Aged; Aged, 80 and over; Arteriosclerosis; Calcinosis; Carotid Artery Diseases; Elastin; Female; Humans; Macrophages; Male; Mast Cells; Middle Aged; Muscle, Smooth, Vascular

Elastolytic matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of abdominal aortic aneurysms (AAA), a disorder characterized by chronic aortic wall inflammation and destruction of medial elastin. The purpose of this study was to determine if human macrophage elastase (HME; MMP-12) might participate in this disease. By reverse transcription-polymerase chain reaction, HME mRNA was consistently demonstrated in AAA and atherosclerotic occlusive disease (AOD) tissues (six of six), but in only one of six normal aortas. Immunoreactive proteins corresponding to proHME and two products of extracellular processing were present in seven of seven AAA tissue extracts. Total HME recovered from AAA tissue was sevenfold greater than normal aorta (P < 0.001), and the extracted enzyme exhibited activity in vitro. Production of HME was demonstrated in the media of AAA tissues by in situ hybridization and immunohistochemistry, but HME was not detected within the media of normal or AOD specimens. Importantly, immunoreactive HME was specifically localized to residual elastin fragments within the media of AAA tissue, particularly areas adjacent to nondilated normal aorta. In vitro, the fraction of MMP-12 sequestered by insoluble elastin was two- to fivefold greater than other elastases found in AAA tissue. Therefore, HME is prominently expressed by aneurysm-infiltrating macrophages within the degenerating aortic media of AAA, where it is also bound to residual elastic fiber fragments. Because elastin represents a critical component of aortic wall structure and a matrix substrate for metalloelastases, HME may have a direct and singular role in the pathogenesis of aortic aneurysms.

Topics: Aortic Aneurysm, Abdominal; Aortic Diseases; Arteriosclerosis; Elastin; Enzyme Induction; Enzyme Precursors; Humans; In Situ Hybridization; Macrophages; Matrix Metalloproteinase 12; Metalloendopeptidases; Reverse Transcriptase Polymerase Chain Reaction; Tunica Media

Using a model of atherosclerosis in minipigs, we analyzed changes in elastic structure within the medial sections of the abdominal aorta and left interventricular coronary artery both in the vicinity of and distal to atheromatous plaques. Twenty-four animals, divided into three groups, were fed either a control diet or a hypercholesterolemic and hyperhomocysteinic atherogenic diet, alone or in association with an antihypertensor, namely isosorbide dinitrate (Risordan). The atherogenic diet, administered for a period of four months, induced in the minipig advanced noncalcified atherosclerotic lesions that were histologically similar to those found in humans. A morphodensitometric analysis of the medial elastic structures was carried out on images obtained from specifically stained transverse arterial sections examined under a light microscope. The volume density of the elastic structures was diminished in the arterial media of the atherosclerotic animals due to opening and widening of the fenestrae in the elastic laminate and increased communication between the interlamellar spaces. Whereas this elastolytic process was uniform and independent of the proximity of atheromatous plaques in the left interventricular coronary artery, it was intensified in the vicinity of the plaques in the abdominal aorta. Overall elastolytic activity was increased in the walls of atheromatous artery in both arterial sites, and metalloproteinases were implied in this increase of activity. We previously reported that treatment with isosorbide dinitrate significantly reduced the moderate systolic hypertension and the increase in transparietal stress observed in the abdominal aorta of atheromatous animals. We report here that isosorbide dinitrate prevented the atherogenic-diet-induced deterioration of the elastic structure in these arteries; complete inhibition of changes to the elastic laminae was evident in areas remote from plaque formation, but only partial inhibition in the vicinity of such plaques. It did not, however, prevent structural damage in the left interventricular coronary artery or modify the increase in parietal elastolytic activity in either of the two arteries. This suggests that damage to the elastic structure in atheromatous arteries is dependent not only on overall elastolytic activity but also on localized factors, possibly related to parietal stresses, affected by the presence of atheromatous plaques.

Topics: Amino Acids; Animals; Aorta, Abdominal; Arteries; Arteriosclerosis; Cholesterol; Coronary Vessels; Densitometry; Diet, Atherogenic; Elastic Tissue; Elastin; Male; Pancreatic Elastase; Swine; Swine, Miniature

We showed recently that human activated lymphocytes express the elastin-laminin receptor. In this study, we were interested in the kinetics of the induction of this receptor on human activated lymphocytes in vitro and in the quantification of its expression on different human lymphocyte subsets. It appears that the expression of the elastin-laminin receptor is a general property of most activated human lymphocytes but strongly dependent on the lymphocyte subsets. It appeared that the helper (CD4+) and memory (CD45RO+) lymphocytes exhibited the strongest increase of elastin-laminin receptor expression when cultured for 72 h in the presence of 2 microg/ml elastin peptides (2.7x10[-8] M) as compared to control cells. Activation of this receptor by elastin peptides triggers the stimulation of biosynthesis and release of a PMN-like elastase. Activated T lymphocytes (mostly helper and memory T cells) are present from early stages of the atherosclerotic process and this release could contribute to the progression of the lesion by engaging a vicious circle with more elastin peptides released attracting more mononuclear cells and increasing their elastase production.

Topics: Antibodies, Monoclonal; Arteriosclerosis; Cells, Cultured; Elastin; Flow Cytometry; Fluorescent Antibody Technique, Indirect; Humans; Immunoenzyme Techniques; Leukocyte Common Antigens; Leukocyte Elastase; Lymphocyte Activation; Receptors, Cell Surface; Receptors, Laminin; T-Lymphocyte Subsets; T-Lymphocytes, Helper-Inducer

The molecular mechanisms predisposing to atherosclerotic aneurysm formation remain undefined. Nevertheless, rupture of aortic aneurysms is a major cause of death in Western societies, with few available treatments and poor long-term prognosis. Indirect evidence suggests that matrix metalloproteinases (MMPs) and plasminogen activators (PAs) are involved in its pathogenesis. MMPs are secreted as inactive zymogens (pro-MMPs), requiring activation in the extracellular compartment. Plasmin, generated from the zymogen plasminogen by tissue-type plasminogen activator (t-PA) or urokinase-type plasminogen activator (u-PA; refs 14,15), has been proposed as a possible activator in vitro, but evidence for such a role in vivo is lacking. Analysis of atherosclerotic aorta in mice with a deficiency of apoliprotein E (Apoe-/-; ref. 18), singly or combined with a deficiency of t-PA (Apoe-/-:Plat-/-) or of u-PA (Apoe-/-:Plau-/-; ref. 19), indicated that deficiency of u-PA protected against media destruction and aneurysm formation, probably by means of reduced plasmin-dependent activation of pro-MMPs. This genetic evidence suggests that plasmin is a pathophysiologically significant activator of pro-MMPs in vivo and may have implications for the design of therapeutic strategies to prevent aortic-wall destruction by controlling Plau gene function.

Topics: Animals; Aortic Aneurysm, Abdominal; Aortic Aneurysm, Thoracic; Arteriosclerosis; Collagen; Diet, Atherogenic; Elastin; Enzyme Activation; Female; Fibrinolysin; Macrophages; Male; Metalloendopeptidases; Mice; Mice, Knockout; Tunica Media; Urokinase-Type Plasminogen Activator

The relationship between atherosclerosis and abdominal aortic aneurysm development is well known. Atherosclerosis cannot explain the whole mechanism. Genetic characters of mechanisms leading to abdominal aortic development is obvious from this study and others. Our study evidences an increased metalloproteases activity in aortic wall proportionally to the size of the abdominal aortic aneurysm. A decrease of aortic wall elastin is evidenced proportionally to the AAA size. Extractable collagen is significantly increased in the aortic wall of patients operated on for aortic rupture.

Topics: Age Factors; Aged; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Aortic Rupture; Arteriosclerosis; Elastin; Female; Humans; Male; Metalloendopeptidases; Middle Aged

Although directional atherectomy (DA) reduces the plaque burden, successful revascularization is not associated with a reduced restenosis rate when compared with percutaneous transluminal coronary angioplasty (PTCA). The purpose of this study was to compare and contrast the vascular response to DA-induced and PTCA-induced injury. Six to 8 weeks after induction of atherosclerosis, PTCA (n = 34) was performed in one iliac artery and DA in the other (n = 30). Arteries were obtained at 6 time points: 1, 3, 5, 7, 14, and 28 days. Eleven arteries that did not undergo an intervention acted as controls. Radiograms obtained before and after intervention and at euthanization were compared. Morphometric, histologic, and immunohistochemical analyses were performed. Both PTCA and DA resulted in an immediate increase in luminal diameter that subsequently decreased over the ensuing month. PTCA caused deep dissection (7 of 8 arteries), often extending to the adventitia, whereas stand alone DA resulted in deep cleft formation (4 of 5). Of the 30 arteries that underwent DA, 4 exhibited an increase in luminal diameter in the absence of tissue retrieval. Thrombus was observed in both the dissection planes and the clefts within the first 7 days, and cellular ingrowth was appreciated at 5 to 7 days. By 7 days the artery was repaired, and the histologic appearance of the arteries that had undergone PTCA could not be differentiated from the arteries that had undergone DA. Increased intimal and medial collagen and elastin was noted at 14 and 28 days. An increase in the area bordered by the external elastic lamina was observed in both groups. Although successful DA results in tissue removal and the production of a deep tissue cleft and PTCA causes a dissection, both produce a condition in which the arterial injury exposes the arterial media to blood, causing thrombus formation and inflammation with subsequent cellular accumulation into the thrombotic framework.

Topics: Angioplasty, Balloon; Angioplasty, Balloon, Coronary; Animals; Aortic Dissection; Arteriosclerosis; Arteritis; Atherectomy; Atherectomy, Coronary; Collagen; Elastic Tissue; Elastin; Iliac Aneurysm; Iliac Artery; Immunohistochemistry; Rabbits; Radiography; Recurrence; Thrombosis; Tunica Intima; Tunica Media; Wound Healing

The elastin peptide level (EP) and elastase-type activity (EA) were investigated in 89 patients with different types of systemic vasculitis (polyarteritis nodosa-14, non-specific aortoarteritis-33, temporal arteritis-23 and thromboangiitis obliterans-18) and compared to the controls: 31 patients with leg atherosclerosis and 12 aged subjects with no evident vascular pathology. EP and EA levels in patients with thromboangiitis obliterans were significantly lower as compared to leg atherosclerosis and the aged control group (p < 0.02 for EA, p < 0.05 for EP). The increase of EP predominated in giant-cell arteritis as compared to the other vasculitic groups (18/56 vs. 5/32, p < 0.05); EA in these patients was the lowest. The activation of elastin degradation after corticosteroid treatment was demonstrated by an increase of EP in temporal arteritis (p < 0.05) and of EA in thromboangiitis obliterans (p < 0.03). We suggest that the determination of the above parameters of elastin degradation may be helpful in the search for differences in mechanisms of vascular damage between atherosclerosis and inflammatory vascular diseases.

Topics: Adolescent; Adrenal Cortex Hormones; Adult; Aged; Aortitis; Arteriosclerosis; Elastin; Female; Giant Cell Arteritis; Humans; Male; Middle Aged; Pancreatic Elastase; Peptides; Polyarteritis Nodosa; Reference Values; Thromboangiitis Obliterans

Tissue destruction in atherosclerosis is partly due to uncontrolled protease and oxygen radical release. In this study we investigated the release of elastase and myeloperoxidase, as well as the production of reactive oxygen species by polymorphonuclear leukocytes (PMNLs) obtained from patients with obliterative atherosclerotic of the lower legs. In addition we measured the plasma concentration of xanthine oxidase. PMNLs of atherosclerotic patients have a greater ability to increase elastase and myeloperoxidase release after their stimulation with formyl-methionin-leucyl-phenylalanin (fMLP) and calcium ionophore, A23187, independently of their age, than PMNLs of healthy middle-aged subjects. Similarly to healthy elderly subjects there was an increased superoxide anion (O2-) production under basal condition in both atherosclerotic patient age-groups. The activation of PMNLs with fMLP and A23187 enhanced O2- formation both in healthy subjects and in patients with atherosclerotic disease of the lower legs, however the increase was significantly less in the latter group. No biochemical parameters showed significant correlation with patient's risk factors, however myeloperoxidase production was significantly higher in less severe stage of the disease (P < 0.05). We found that patients with atherosclerotic disease of the lower legs have higher plasma xanthine oxidase level than control subjects. This study indicates an other piece of evidence suggesting the activation and involvement of neutrophils in the pathogenesis of atherosclerosis of the lower legs. The similar tendencies in the reactivity of neutrophils during aging and in atherosclerosis suggest that atherosclerosis may be an early aging process.

Topics: Adult; Aged; Arteriosclerosis; Calcimycin; Cell Degranulation; Elastin; Humans; Hydrogen Peroxide; Ionophores; Leukocyte Elastase; Middle Aged; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Pancreatic Elastase; Peroxidase; Respiratory Burst; Superoxides; Xanthine Oxidase

Whether the arterial elastic structures are involved in the beneficial effects of long-term treatment with organic nitrates on atherosclerosis-induced changes in hemodynamics and arterial wall viscoelastic properties, are case for angiotensin-converting enzyme (ACE) inhibitors, is not known. In the present study, atherogenic (A) diet, and isosorbide dinitrate (ISDN) (I) (60 mg Risordan LP, daily dose) were given concomitantly for 4 months to adult Pitman-Moore minipigs (A + I animals, n = 8), which were compared with A (n = 8) or control (C, n = 8) animals. Blood flow was investigated by hemodynamics in the hindlimb arterial bed; and wall rheology, histomorphometry and elastin; and desmosine (DES) and isodesmosine (IDE) contents in the abdominal aorta. Atherosclerosis prominently impaired the function of capacitance and resistance arteries, altered blood pressure contours, increased aortic stiffness and wall tension, and reduced parietal viscoelasticity through viscous component blunting. The treatment with ISDN significantly improved aortic pulsatility, arteriolar opposition to blood flow, and blood pressure (BP) contours by restoring, at least in part, the wall viscoelastic properties. However, there was no significant change in the area of the pressure-diameter curve hysteresis between the three animal groups. In contrast, ISDN reduced neither the cross-sectional area of lesions nor the losses in wall elastin content and had no influence on lipid accumulations in vessels and in the blood. The present results demonstrate that the beneficial hemodynamic and wall viscoelastic effects elicited by ISDN in atherosclerotic minipigs are not accounted for by therapeutic properties of the nitric oxide (NO) donor against alterations of elastic structures, but by the viscoelastic properties in the arterial wall.

Topics: Animals; Arteries; Arteriosclerosis; Cholesterol; Elasticity; Elastin; Hemodynamics; Isosorbide Dinitrate; Male; Swine; Swine, Miniature; Vasodilator Agents; Viscosity

This study focuses on the fortuitous discovery of an atypical atherosclerotic lesion in four of 49 male adult cynomolgus monkeys (macacus fascicularis) which were maintained for a long time at a high level of hypercholesterolemia, and in seven of 19 female cynomolgus monkeys examined from the second to the 24th week of hypercholesterolemic diet: this lesion was in formation or already mature during this period of diet. This atypical lesion was formed by a collagen and elastic network surrounding synthetic smooth muscle cells without fibrofatty or fibrous plaques. Lipids were occasionally seen in the inner intima. The lesion appeared early (from the third week of diet). Once established, its morphology did not change. It became more extensive, but was not complicated by lipid overload in spite of prolonged, permanent hypercholesterolemia. This response to hypercholesterolemia is interesting because the activity of the smooth muscle cells differs from that observed in the classic lesion: they intervene earlier, their replication is very marked and rapid, their elastin secretion is greater and remains constant over time, and their phagocytic properties are reduced. This experimental study examines the installation and the maintenance of this lesion and raises the problem of its origin.

Topics: Animals; Aorta, Abdominal; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Cell Division; Collagen; Coronary Vessels; Diet, Atherogenic; Elastin; Female; Hypercholesterolemia; Lipids; Macaca fascicularis; Macrophages; Male; Muscle, Smooth, Vascular

Micro-methods are described for the serial determinations of elastin metabolism related parameters in human serum or plasma samples: serum elastase activity, elastase inhibitor titers and elastin peptide conc-s. These methods were used in an epidemiological study (the EVA study, " Etude du vieillissement vasculaire") carried out in Nantes, west of France on several thousand individuals. Blood samples obtained from the first-1389 individuals (574 males, 815 females) were used for the determinations. In order to carry out this large number of determinations previously described procedures had to be modified. These methods used for the large serial determinations of the above mentioned three elastin metabolism related serum (or plasma) parameters are described because of their potential interest for serial clinical investigations.

Topics: Aged; Aging; Arteriosclerosis; Biological Assay; Elastin; Endothelium, Vascular; Female; Humans; Lipids; Male; Pancreatic Elastase; Proteinase Inhibitory Proteins, Secretory; Proteins; Risk Factors; Serine Proteinase Inhibitors

To understand the balance of proteinase antiproteinase activity and the production of extracellular matrix (ECM) at the site of arterial injury, we analyzed the composition of ECM and proteinase activity in normal internal mammary arteries, tissue samples obtained from atherosclerotic coronary lesions and restenotic lesions obtained during directional coronary atherectomy. Histologically and biochemically, collagen and proteoglycans increased, and elastin decreased in samples from restenotic lesions when compared to samples taken from patients undergoing their first revascularization (de novo). In contrast, cellularity was increased in samples obtained from de novo patients as compared to samples obtained from restenotic lesions. Intrinsic activity of matrix metalloproteinases (MMPs) was measured by using zymography and scanning all the lytic bands in zymographic gel. In these gels, identical amounts of total protein were loaded in each lane. MMP activity was determined as % of the total (latent and active) MMPs after trypsin activation (100%) in the normal artery. Intrinsic MMP activity was reduced to 6% +/- 1% in atherosclerotic lesions and 1% +/- 1% in restenotic lesions, when compared to activity found in normal (10% +/- 3%) arteries. Based on solubilization of fluorescein-conjugated elastin by the extracts, the MMP-mediated elastinolytic activity was 0.2 +/- 0.1, 8.8 +/- 1.5, and 24.0 +/- 3 nmol/min/mg in restenotic, native atherosclerotic and normal tissue, respectively. The results suggested that, in arterial tissue from patients with angiographic restenosis, there is an increased production of ECM collagen and a decrease in MMP activity compared to both normal artery and atherosclerotic samples from de novo patients undergoing an initial revascularization procedure of a significant coronary artery lesion.

Topics: Angioplasty, Balloon; Arteriosclerosis; Atherectomy; Collagen; Coloring Agents; Coronary Disease; Coronary Vessels; Elastin; Extracellular Matrix Proteins; Glycoproteins; Humans; Internal Mammary-Coronary Artery Anastomosis; Metalloendopeptidases; Models, Biological; Proteoglycans; Recurrence; Tissue Inhibitor of Metalloproteinases; Wound Healing

The purpose of this study was to characterize the distribution of aortic wall microvessels in normal aorta, atheroocclusive disease (AOD), and abdominal aortic aneurysms (AAA) and to evaluate whether medial neovascularization (MNV) is a reliable histopathologic marker of aneurysmal degeneration.. Aortic tissue specimens (9 normal, 10 AOD, and 10 AAA) were examined for elastin with Verhoeff-van Gieson stain and for Ulex europaeus type I lectin, an endothelial-specific antigen, and laminin, a marker of basement membranes, by immunohistochemistry. The density of MNV was determined by morphometry of aortic sections stained for endothelium. The spatial distribution of aortic microvessels was compared with that of elastin destruction and chronic inflammation.. Evidence of medial neovascularization was generally not observed in normal aorta or AOD, whereas AAAs showed strong spatial correlations between MNV, disruption and degradation of elastin, and chronic inflammation in the outer aortic wall. Several specimens of AOD had focal areas of MNV associated with localized elastin fragmentation and monocytic infiltration located at the interface between the atherosclerotic plaque and the inner media. The density of MNV was about fifteenfold higher in AAA compared with normal aorta and about threefold higher compared with AOD (microvessels per high-power field): normal aorta, 0.77 +/- 0.28; AOD, 3.40 +/- 0.51; AAA, 11.32 +/- 1.58 (ANOVA, p < 0.001).. The presence and density of MNV in the abdominal aorta is a consistent histopathologic marker of aneurysmal degeneration that is spatially correlated with the destruction of elastin and chronic inflammation. The observation of focal MNV in some specimens of AOD, associated with partial elastin disruption, raises the possibility that early changes of aneurysm disease might develop by an extension of angiogenic/inflammatory processes from the atherosclerotic plaque into the aortic media.

Topics: Adult; Aged; Analysis of Variance; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Arterial Occlusive Diseases; Arteriosclerosis; Elastin; Endothelium, Vascular; Female; Humans; Immunohistochemistry; Laminin; Lectins; Male; Middle Aged; Neovascularization, Pathologic; Tunica Media

To test the hypothesis that atherosclerosis may be initiated by hypoperfusion or thrombotic occlusion of the adventitial vasa vasonum.. In a new model of atherogenesis, an early atherosclerotic lesion may be initiated by removal of the adventitia from the carotid artery of the New Zealand White rabbit, wherein lie the vasa vasorum.. Animal laboratory, University Department of Surgery and Medicine.. Immunocytochemistry was undertaken to demonstrate the presence of smooth muscle cells and macrophages within the intimal lesions. Smooth muscle cells were labelled with a monoclonal antibody designated HHF35 and macrophages were labelled with a rabbit specific, macrophage specific antibody, RAM11. CHIEF RESULTS: In rabbits fed a normal diet, at day 14, the intimal lesion was composed exclusively of smooth muscle cells. By day 28, such lesions had regressed. In rabbits fed a high cholesterol diet, at day 14, the intimal lesion was composed of a mixture of macrophages and smooth muscle cells. By day 42, the pattern of cellular distribution was such that macrophages (present as foam cells) were predominant. In the presence of persistent hypercholesterolaemia these lesions did not regress.. This new model can produce two different cellular responses that may mimic the intimal lesions seen with re-stenosis after angioplasty or in hypercholesterolaemic man and as such, might be useful in separating out these two different pathophysiologies.

Topics: Animals; Arteriosclerosis; Carotid Arteries; Carotid Artery Diseases; Collagen; Elastic Tissue; Elastin; Endothelium, Vascular; Foam Cells; Hypercholesterolemia; Immunohistochemistry; Ischemia; Macrophages; Male; Microscopy, Electron; Muscle, Smooth, Vascular; Rabbits; Thrombosis; Tunica Intima

While localization of atherosclerosis and aneurysms to the infrarenal aorta has been attributed, in part, to hemodynamic factors, anatomic differences between the proximal and the distal aorta may also be important. Our purpose was to determine the changes in content and organization of major structural proteins (elastin and collagen) throughout the normal human aorta.. Biochemical analysis for desmosine-isodesmosine (elastin) and hydroxyproline (collagen) content was done by HPLC on complete 1-cm transverse rings removed from the ascending and descending thoracic aorta and abdominal supraceliac, suprarenal, and midinfrarenal aorta. Elastin and collagen content was normalized to lumenal surface area and compared by ANOVA: Light microscopy and optical micrometry were used to determine changes in intimal, medial, and adventitial thickness and number of elastin lamellae at each level.. Both collagen/cm2 and elastin/cm2 decrease from the proximal to distal aorta. Collagen content did not differ among the three abdominal segments, but there was a 58% decrease in elastin between the suprarenal and the infrarenal aorta. The proportion of elastin and collagen does not differ throughout the aorta except in the infrarenal aorta where there is decreased elastin relative to collagen.. Collagen and elastin in the distal aorta bear an increased load as compared to the proximal aorta. The infrarenal aorta differs biochemically and histologically from the remainder of the aorta. A decrease in infrarenal elastin without a corresponding decrease in collagen may effect the compliance and integrity of the distal aorta. These anatomic differences may be important in predisposing the infrarenal aorta to atherosclerosis and aneurysm formation.

Topics: Adult; Aorta; Aortic Aneurysm; Aortic Diseases; Arteriosclerosis; Collagen; Elastin; Female; Humans; Male

Ageing of the arterial wall is defined as the age-related structural and functional changes in arteries. These changes include distension of the lumen, kinking of the artery, and rigidity of the arterial wall. Distension of the arterial luminal diameter with hardening of the arterial wall causes chronic ischemia in peripheral tissues, leading to age-related deterioration of the organs. The ensuing pathological modification in blood circulation is mainly linked to the decrease in the elastic recoil of the arteries and to the increasing difficulty of pumping systolic blood volume towards the periphery. This results in increased systolic blood pressure in the elderly and an increasing load on the ageing heart. Age-related changes in elastic arteries are characterized as degenerative changes in the SMCs of the media associated with depositions of collagen fibers and the fragmentation of elastic fibers. Data obtained from in vivo experiments indicate that the susceptibility of aged arteries to atherogenic stimuli might be related to intrinsic cellular changes with age. Substances that can regulate the function of vascular wall cells may be continuously present in the vessel walls, perhaps as components of super-extracellular matrix complexes. One type of substance is the functional domain structure of extracellular matrix molecules exposed to specific receptors or binding proteins on the surface of the cells. The role of extracellular matrices, especially elastin, on cultured vascular cells has been discussed.

Topics: Adult; Aged; Aged, 80 and over; Aging; Amino Acid Sequence; Aorta; Arteriosclerosis; Elastin; Female; Humans; Molecular Sequence Data

The dipolar-decoupled, natural abundance Fourier transform and cross polarization [13C] NMR spectra of human elastin isolated from atherosclerotic aorta and aortas free of atherosclerotic lesions, bovine insoluble elastin and bovine kappa-elastin were obtained at 75 MHz, with 5-7 kHz magic angle sample spinning. Spin-lattice rotating frame relaxation parameters were measured for protons (T1pH) and for carbons (T1pC) at room temperature. Proton relaxation times were shorter for bovine kappa-elastin (T1pH = 1.7 ms) than for bovine elastin (T1pH) = 3.5 ms). Calculation of T1pH showed no differences between human normal and atherosclerotic elastins. T1pC were shorter for bovine kappa-elastin than for bovine elastin. While alpha-carbons of human atherosclerotic elastin had shorter T1pC than normal elastin alpha carbons, carbons from hydrophobic amino acid side chains had longer T1pC for atherosclerotic then for normal elastin. Biochemical studies of aortic wall and purified elastin showed significantly increased content of lipids (atherosclerotic 67.7 mmol/g elastin, control 54.7 mmol/g elastin) and calcium (atherosclerotic 38.3 mmol/g elastin, control 19.6 mmol/g elastin). Changes in relaxation parameter values may be caused by the structural and biochemical changes in human elastin. Increased mobility of polypeptide chains as based on the model kappa-elastin studies is caused by the action of elastase. Restriction of mobility is expected to be caused by the accumulation of lipids and calcium.

Topics: Analysis of Variance; Animals; Aorta; Arteriosclerosis; Calcium; Carbon Isotopes; Cattle; Elastin; Fourier Analysis; Humans; Lipids; Magnetic Resonance Spectroscopy; Muscle, Smooth, Vascular; Reference Values

Laser-induced fluorescence (LF) spectroscopic analysis of the chemical composition of atherosclerotic plaque was examined.. The intima of 18 dog aortas was injected with chemical compounds found in atherosclerotic plaque. Spectra were recorded in air prior to and after injection of collagens I, III and IV, elastin, cholesterol, triglyceride, and beta-nicotinamide adenine dinucleotide (NADH).. Significant changes in LF intensity were detected after injection of collagens I and III, cholesterol and elastin in thoracic aorta (P < 0.001), but not with triglyceride or NADH. Minor changes were detected in abdominal aorta. Multiple regression analysis of LF intensity ratios demonstrated a clear correlation with the quantity of injected collagens I (R2 = 0.90-0.99) and III (R2 = 0.84-1.0), cholesterol (R2 = 0.72-0.76), and triglyceride (R2 = 0.68-0.80) in both thoracic and abdominal aorta. The correlation between LF and atherosclerotic plaque composition was confirmed in a rooster model of atherosclerosis where multiple regression analysis predicted the measured aortic cholesterol (R2 = 0.78) and triglyceride content (R2 = 0.96).. (1) Fluorescence spectra recorded from dog aorta were significantly altered by injection of collagens I and III, cholesterol, and elastin. (2) LF may allow quantitative assessment of plaque chemical content.

Topics: Analysis of Variance; Animals; Aorta; Aorta, Abdominal; Arteriosclerosis; Chickens; Cholesterol; Collagen; Dogs; Elastin; Herpesvirus 2, Gallid; In Vitro Techniques; Lasers; Male; Reference Values; Regression Analysis; Sensitivity and Specificity; Spectrometry, Fluorescence; Triglycerides

A new structural model is described for the tension-radius relationship of blood vessels, taking into account their mechanically important constituents: collagen, elastin and smooth muscle. The model has four characteristic parameters: EC, the Young's modulus of the collagen fibres; ESE, the Young's modulus of the combined smooth-muscle/elastin network; epsilon mu, the amount of strain at which the high stiffness region on the tension-radius curve is reached, and eta an indicator for the degree of collagen fibre stretching. The structural stiffness of the wall constituents is reflected by EC and ESE whereas the global stiffness of the entire blood vessel is described by epsilon mu and eta. All these elasticity parameters are pressure independent, in contrast to generally quoted values for the incremental modulus or vascular compliance which are strongly pressure dependent. Hence, an objective comparison of the mechanical properties for various types of blood vessel, based on the present model parameters, has been made possible. The model was successfully fitted to tension-radius data of 65 human aortas, age range 30-88 years, with moderate or severe atherosclerosis. The structural as well as the global stiffness changes with age, e.g. collagen stiffness shows a ninefold increase over 60 years. Global stiffness depends on atherosclerosis.

Topics: Adult; Aged; Aged, 80 and over; Aging; Aorta; Aorta, Abdominal; Aorta, Thoracic; Arteriosclerosis; Collagen; Elasticity; Elastin; Humans; Mathematics; Middle Aged; Models, Cardiovascular; Models, Structural; Muscle Development; Muscle, Smooth, Vascular; Pressure; Regression Analysis; Reproducibility of Results

The formation of calcified deposits in intimal thickenings of human aorta was studied by electron microscopy. Microzones of calcification were detected in about 20% of fatty streaks and were located predominantly in the deep musculoelastic layer of the intima. Calcified deposits formed only on previously existing structures including extracellular vesicles and unesterified cholesterol. Calcified deposits in the musculoelastic layer of the intima localised inside altered elastin fibres, but initiating the calcification of of elastin required the prior accumulation of cholesterol esters inside elastin fibres. Co-localization of calcified deposits and elastin fibres was followed by destruction of elastin. The present study suggests that at an early stage of development is atherosclerotic lesions, calcified deposits are formed by a physicochemical process which is not strongly controlled by the intimal cells. The recognition of calcified deposits in intimal thickenings support the hypothesis that a subset of fatty streaks might progress to fibrous plaques in human atherosclerosis.

Topics: Adolescent; Adult; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Calcinosis; Elastin; Humans; Male; Middle Aged; Tunica Intima

The walls of human abdominal aortas and atherosclerosis-induced aneurysms contain similar amounts of collagen. The quantitative ratio between collagens of various types of this protein does not differ significantly either, whereas solubility of the collagen in aneurysmal wall and its susceptibility to the action of EDTA are distinctly decreased. In contrast with collagen, the amount of elastin in aneurysms is significantly lower. Total amount of glycosaminoglycans slightly decreased as compared with that of normal tissue, but the ratio of particular compounds varies. The percentage of chondroitin sulphate is increased and that of heparan sulphate significantly decreased. The significance of these changes in pathogenesis of aneurysms is discussed.

Topics: Adult; Aged; Aging; Aortic Aneurysm, Abdominal; Arteriosclerosis; Case-Control Studies; Chondroitin Sulfates; Collagen; Elastin; Female; Glycosaminoglycans; Humans; Keratan Sulfate; Male; Middle Aged; Solubility

In order to explore the potential role and importance of elastin fiber degradation in atherogenesis we determined in more than 1,400 individuals (males and females between 59 and 71 years of age), [the EVA epidemiological study] serum parameters related to elastin fiber degradation: serum elastase activity, circulating elastin peptides and serum elastase inhibitor titers. Significant correlations were found these between parameters and several other serum constituents considered as risk-factors of atherogenesis--essentially serum lipid-parameters and glycemia as well as several other biological factors. These correlations confirm the validity of the underlying hypothesis concerning the interest of the clinical determinations of these elastin-related parameters and the potential role of the permanent activation of the endothelial elastin-receptor in atherogenesis.

Topics: Aged; Aging; Arteriosclerosis; Elastic Tissue; Elastin; Female; Humans; Male; Middle Aged; Pancreatic Elastase; Risk Factors

An antibody to elastin-derived chemotactic peptide Val-Gly-Val-Ala-Pro-Gly was used to study human artery samples from 18 patients with various vascular lesions, such as aneurysms or occlusive arteriopathy. The antibody recognised epitopes in two artery specimens, one occlusive arteriopathy and one aneurysm, and both specimens were also characterised by a segmental destruction of media. The positive staining for the peptide was located in the elastic membranes and endothelial cells that were also stained with antibodies to IgG. This study suggests that elastin-derived chemotactic peptides may have a role in vascular lesions characterised by a destruction of media and a formation of aneurysm. Since elastin-derived chemotactic peptides are more chemotactic to monocytes than to neutrophils, it is possible that mononuclear phagocytes are involved in the segmental destruction of elastin.

Topics: Adult; Aged; Aortic Aneurysm, Abdominal; Aortic Dissection; Arterial Occlusive Diseases; Arteries; Arteriosclerosis; Arteritis; Chemotactic Factors; Elastic Tissue; Elastin; Endothelium, Vascular; Female; Humans; Immunoenzyme Techniques; Male; Middle Aged; Peptides; Tunica Media; Vascular Diseases

Remodeling of the vessel wall after balloon angioplasty injury is incompletely understood, and in particular, the role of extracellular matrix synthesis in restenosis has received little attention. The objective of the present study was to determine the sequence of changes in collagen, elastin, and proteoglycan synthesis and content after balloon injury and to relate these changes to growth of the intimal lesions and extent of cell proliferation. In a double-injury non-cholesterol-fed model, right iliac arterial lesions in 43 rabbits were treated with balloon angioplasty, and the rabbits were killed at five time points ranging from immediate to 12 weeks. Vessel wall collagen and elastin content and synthesis were measured after incubation with 14C-proline and separation with a cyanogen bromide extraction procedure. Sulfated glycosaminoglycan synthesis was measured after incubation with [35S]sulfate, papain digestion, and ethanol precipitation. Continuous in vivo infusion of bromodeoxyuridine (96 hours) was used to assess cell proliferation. The intimal area significantly increased from 0.27 +/- 0.08 to 0.73 +/- 0.11 mm2 between 0 and 12 weeks. Intimal and medial cell proliferation were modest and peaked at 1 week (labeling indexes of 4.8% and 3.0%, respectively) and then markedly declined by 2 weeks. Significant increases in collagen, elastin, and proteoglycan synthesis, up to 4 to 10 times above control nondamaged contralateral iliac arteries, were noted at 1, 2, and 4 weeks. These increases in synthesis were accompanied by significant increases in collagen and elastin content (by approximately 35%) that coincided with the temporal increase in cross-sectional area.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Angioplasty, Balloon; Animals; Arteriosclerosis; Cell Division; Collagen; Constriction, Pathologic; Elastin; Extracellular Matrix; Glycosaminoglycans; Histological Techniques; Iliac Artery; Male; Rabbits; Recurrence; Time Factors; Tunica Intima; Tunica Media

Dysregulated extracellular matrix (ECM) metabolism may contribute to vascular remodeling during the development and complication of human atherosclerotic lesions. We investigated the expression of matrix metalloproteinases (MMPs), a family of enzymes that degrade ECM components in human atherosclerotic plaques (n = 30) and in uninvolved arterial specimens (n = 11). We studied members of all three MMP classes (interstitial collagenase, MMP-1; gelatinases, MMP-2 and MMP-9; and stromelysin, MMP-3) and their endogenous inhibitors (TIMPs 1 and 2) by immunocytochemistry, zymography, and immunoprecipitation. Normal arteries stained uniformly for 72-kD gelatinase and TIMPs. In contrast, plaques' shoulders and regions of foam cell accumulation displayed locally increased expression of 92-kD gelatinase, stromelysin, and interstitial collagenase. However, the mere presence of MMP does not establish their catalytic capacity, as the zymogens lack activity, and TIMPs may block activated MMPs. All plaque extracts contained activated forms of gelatinases determined zymographically and by degradation of 3H-collagen type IV. To test directly whether atheromata actually contain active matrix-degrading enzymes in situ, we devised a method which allows the detection and microscopic localization of MMP enzymatic activity directly in tissue sections. In situ zymography revealed gelatinolytic and caseinolytic activity in frozen sections of atherosclerotic but not of uninvolved arterial tissues. The MMP inhibitors, EDTA and 1,10-phenanthroline, as well as recombinant TIMP-1, reduced these activities which colocalized with regions of increased immunoreactive MMP expression, i.e., the shoulders, core, and microvasculature of the plaques. Focal overexpression of activated MMP may promote destabilization and complication of atherosclerotic plaques and provide novel targets for therapeutic intervention.

Topics: Arteries; Arteriosclerosis; Carotid Arteries; Collagenases; Elastin; Extracellular Matrix; Frozen Sections; Glycoproteins; Humans; Immunohistochemistry; Leukocyte Common Antigens; Matrix Metalloproteinase 1; Matrix Metalloproteinase 3; Matrix Metalloproteinase 9; Metalloendopeptidases; Proteins; Tissue Distribution; Tissue Inhibitor of Metalloproteinase-2; Tissue Inhibitor of Metalloproteinases

The rate of calcification within the human thoracic aorta from completion of body growth to advanced old age was examined. Fifty-eight aortae, obtained at necropsy, were dissected into four layers: the complete intima and the separated media, which was subdivided into three tissue samples of equal thickness, defined as the media-inner, -middle, and -outer layers. The sampling sites selected for analysis were from regions of the aortic surface that were free of atherosclerotic plaques. The calcium content within each tissue layer of the aorta was determined. Arterial wall thickness and the cholesterol content of the four layers were also measured. Intimal calcification increased progressively during aging: from 1.6 micrograms Ca/mg tissue at 20 years of age to 5.2 micrograms Ca/mg tissue by 90 years of age. When intima calcium concentration was expressed by tissue volume (w/v), no significant change during aging was found. Medial calcification, as w/v and by w/w, increased throughout aging. Calcium accumulation was most marked in the middle, elastin-rich layer of the media, increasing from 1.4 micrograms Ca/mg tissue at 20 years of age to 49.50 micrograms Ca/mg tissue by 90 years of age. Calcium levels also increased in the other media layers, but at a slower rate than that found within the middle media.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aging; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Calcinosis; Calcium; Cholesterol; Cohort Studies; Elastin; Female; Humans; Male; Middle Aged

Abdominal aortic aneurysms (AAA) are associated with diffuse arteriomegaly and peripheral aneurysms, suggesting a generalized process. Elastin and collagen are the key structural proteins of the aorta, and their relative content is markedly altered in tissue from AAA. Our purpose was to investigate elastin and collagen content in the proximal, nonaneurysmal segments of aortas with infrarenal AAA.. After extraction of lipid, calcium, and soluble proteins, hydroxyproline (collagen) and desmosine-isodesmosine (elastin) contents were determined by high-performance liquid chromatography in the ascending and descending thoracic, supraceliac, and suprarenal aorta. By repeated measures of analysis of covariance, collagen was found to be increased throughout the aorta in AAA as compared with normal aorta or aorta with atherosclerotic occlusive disease. This difference remained significant when adjustments were made for group differences in age and degree of atherosclerosis. This increase in collagen content results in a dilutional decrease in elastin concentration. These data demonstrate that the same matrix protein alterations found in AAA tissue occur throughout the aorta, differing only in magnitude in the aneurysmal and nonaneurysmal segments. These data suggest that aneurysm formation may related to alterations in the regulation of elastin and collagen.

Topics: Adult; Aged; Analysis of Variance; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Arteriosclerosis; Chromatography, High Pressure Liquid; Collagen; Elastin; Extracellular Matrix Proteins; Female; Humans; Linear Models; Male

One-month-old male New Zealand White rabbits were fed either a cholesterol-free casein diet (n = 10) or low-level cholesterol-supplemented chow (n = 10) for 24 weeks, during which total plasma cholesterol levels were matched. After perfusion fixation, aortic tissue samples were taken from six predetermined locations and embedded in epoxy resin for examination by light and electron microscopy. Frozen sections were also obtained for histochemical demonstration of collagen and elastin. Lesion morphology was classified in toluidine blue-stained, semithin epoxy sections as early fatty streaks (round foam cells with little intervening extracellular matrix); advanced fatty streaks (foam cells with extracellular lipid); fibrous plaques (spindle-shaped cells within extracellular matrix); or atheromatous lesions (presence of an atheromatous core). In representative specimens, electron microscopy showed that the ultrastructure of round foam cells was consistent with macrophage derivation, whereas most spindle-shaped cells were clearly smooth muscle cells. Fibrous plaques were more common in the distal than the proximal aorta. Lesions in the casein-fed animals were essentially equally distributed among the four morphological categories, whereas lesions in the cholesterol-fed rabbits were predominantly of the atheromatous type. Thus, cholesterol-fed rabbits had, in general, more advanced lesions than casein-fed rabbits with matched total plasma cholesterol levels. Moreover, the feeding of a low-level cholesterol diet (0.125% to 0.5% by weight) to rabbits for a relatively short time (6 months) led to the development of advanced lesions similar to those seen in humans.

Topics: Animals; Aorta; Arteriosclerosis; Caseins; Cholesterol; Cholesterol, Dietary; Collagen; Dietary Proteins; Disease Models, Animal; Elastin; Histocytochemistry; Male; Microscopy, Electron; Rabbits

We have previously shown that high-frequency, high-resolution ultrasound can characterize the acoustic properties and composition of fatty plaques in cholesterol-fed rabbits. To determine whether quantitative ultrasound can delineate the regression of atherosclerotic lesions by detecting a change in their composition from fatty to fibrous types induced by alterations in dietary regimen, we fed six New Zealand White rabbits a 2% cholesterol diet for 3 months, followed by a standard diet for 3 additional months to promote the development of fibrous intimal lesions. Segments of aortas were excised, and backscattered radiofrequency data were acquired from 400 to 600 independent sites in each specimen with an acoustic microscope operated at 50 MHz. Control data were provided by measuring backscatter from adjacent portions of the aortas devoid of lesions. Histological and immunocytochemical analyses of the fibrous intimal lesions confirmed the presence of smooth muscle cells and abundant connective tissue with little appreciable lipid. Backscatter from normal aortic segments (-30.7 +/- 1.0 dB) was approximately 10-fold greater than that from fibrous lesions (-42.4 +/- 1.0 dB; P < .05). We previously reported that integrated backscatter from fatty lesions was -50.6 +/- 0.7 dB, or approximately 10-fold less than that from fibrous lesions (P < .05). Values for integrated backscatter from the media of each tissue type were approximately equal (-30.0 +/- 1.7 versus -30.7 +/- 1.6 versus -33.4 +/- 0.8 dB for normal versus fibrous versus fatty tissues, respectively; P = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Actins; Animals; Aorta; Arteriosclerosis; Cholesterol, Dietary; Elastin; Immunohistochemistry; Macrophages; Rabbits; Staining and Labeling; Ultrasonography

This study examines the hypothesis that progressive intimal thickening and atherosclerosis in the larger pulsatile arteries arise from failure to maintain, subjacent to the endothelial cells, a substantial elastin membrane, a component which has been shown to be of special structural significance. The internal thoracic arteries of 293 subjects of all ages up to 60 years were compared histologically with the anterior descending coronary arteries of the same individuals by light- and electronmicroscopy and immunoperoxidase staining for macromolecules. The internal thoracic arteries usually developed a new robust reduplicated internal elastic lamina at an early age, no further intimal thickening, and no significant entry of lipid or cells to the intima. The coronary arteries showed areas of rapid intimal thickening with poor and incomplete reduplicated internal elastic laminae, entry of lipid, macrophages, and other cells to the intima. The reduplicated internal elastic laminae appeared to be formed primarily by the endothelial cells themselves. An elastin membrane subjacent to the endothelial cells appears to be essential. It provides a secure attachment for the cells and a barrier to the entry of macromolecules and cells to the intima. Its absence is associated with progressive intimal thickening and atherosclerosis.

Topics: Adolescent; Adult; Arteries; Arteriosclerosis; Child; Child, Preschool; Coronary Vessels; Elastic Tissue; Elastin; Endothelium, Vascular; Humans; Immunoenzyme Techniques; Infant; Infant, Newborn; Microscopy, Electron; Middle Aged; Thoracic Arteries; Tunica Intima

Topics: Antigens; Aorta; Arteriosclerosis; Cross Reactions; Elastin; Humans; Peptides

Doxazosin was administered to rabbits fed diets enriched in cholesterol and peanut oil for 7.5 or 12 weeks, in 2 separate experiments. Doxazosin suppressed the accumulation of cholesterol and formation of atherosclerotic plaques in the aortas of treated rabbits and prevented a diet-induced increase in aortic collagen and wall mass. Doxazosin was more effective in the thoracic and abdominal segments of the aorta than in the aortic arch. Pharmacokinetic analysis indicated that treated rabbits were exposed to concentrations of doxazosin, integrated over 24 h, which were consistent with the therapeutic range of doxazosin measured in patients treated for hypertension. Doxazosin did not alter serum levels of cholesterol or triglycerides, nor were there any consistent effects on glucose, free fatty acid or ketone levels. Hypotheses of the mechanism of action of doxazosin are discussed, including the possible involvement of alpha 1-adrenergic receptors in recruitment of smooth muscle cells by subintimal macrophages and nonadrenergic mechanisms of inhibition of lipid infiltration.

Topics: Animals; Aorta; Arteriosclerosis; Cholesterol; Cholesterol, Dietary; Collagen; Doxazosin; Elastin; Lipid Metabolism; Male; Rabbits

Measurements of total collagen, of the ratio of collagen types III/(I+III) and of sulphated glycosaminoglycans (GAGs) were compared with mechanical strength for individual ulcerated and non-ulcerated human aortic plaque caps and with intima adjacent to the plaques. The distributions of the collagen type ratio were similar for both ulcerated and non-ulcerated plaque caps but different from that of the adjacent intima. The proportions of different collagen types were not related to fracture stress and are thus unlikely to affect the potential to ulcerate. The distributions of the sulphated GAGs showed lower amounts for the plaque caps compared with the nearby intima, with the centres of ulcerated plaque caps having the lowest values. Total collagen had higher values in the peripheries of plaque caps compared with the nearby intima, but was distinctly lower in the centres of ulcerated plaque caps. Plaque caps appeared to require a higher collagen content than adjacent intima to support a given level of mechanical strength, suggesting that while collagen production had occurred in the plaque caps it was not as efficiently organized to resist fracture as a similar amount of collagen in the adjacent intima. Ulcerated plaque caps are notable for much larger transverse (centre vs. periphery) gradients of connective tissue constituents than for non-ulcerated plaque caps. The development of these transverse gradients may be a critical aspect in determining the propensity of a plaque to ulcerate.

Topics: Aortic Diseases; Arteriosclerosis; Chondroitin Sulfates; Collagen; Dermatan Sulfate; Elastin; Glycosaminoglycans; Hexosamines; Humans; In Vitro Techniques; Tensile Strength; Uronic Acids

We have developed a method for using near infrared Raman spectroscopy to quantitatively analyze the histochemical composition of human artery. The main contributors to bands observed in the Raman spectra of normal and atherosclerotic aorta are the proteins collagen and elastin, cholesterol lipids, and calcium hydroxyapatite. The Raman scattering cross-sections of different bands for these components have been determined in order to understand their relative contributions to the Raman spectra of biological tissue. The Raman signal is observed to behave linearly with the concentration of the components, even in a highly scattering medium such as a powder. Using these data, we have developed a linear model that can be used to extract the quantitative contribution of an individual component to the spectrum of a mixture. The model has been applied to several mixtures of known composition of tissue constituents in order to evaluate its precision and accuracy. The calculated fit coefficients from the spectra are in agreement with the measured values within experimental uncertainties. The spectra of different types of atherosclerotic aorta have also been modeled, and we have extracted quantitative information regarding the relative concentration of biological constituents in atherosclerotic aorta.

Topics: Arteries; Arteriosclerosis; Cholesterol; Cholesterol Esters; Chondroitin Sulfates; Collagen; Elastin; Fourier Analysis; Humans; Hyaluronic Acid; Muscle, Smooth, Vascular; Palmitic Acid; Palmitic Acids; Spectrophotometry, Infrared; Spectrum Analysis, Raman; Triglycerides

To elucidate whether tissue fibronectin increases in the early stages of atherogenesis induced by hypercholesterolemia without mechanical trauma, we investigated sequential changes in the distribution of tissue fibronectin during fatty streak initiation and maturation in the aortas of hypercholesterolemic fat-fed rabbits. The presence of fibronectin was examined on immunoperoxidase stained tissue specimens with the aid of a microscope-photometric technique. Twenty male albino rabbits were used. Cholesterol supplemented chow (1%) was given for 4 weeks (n = 6), 8 (n = 5) or 14 weeks (n = 5). A membrane-like layer positive for fibronectin was observed along the endothelium in the normal aorta. After 4 weeks of the cholesterol-feeding, fatty streaks were initiated in the intima, where fibronectin was more densely accumulated than the normal intima. After 8 weeks of the cholesterol-feeding, fatty streaks were expanding, associated with the dense staining for fibronectin. After 14 weeks, fibronectin was still concentrated in the endothelial layer and also in the superficial areas of the thickened intima, but decreased in the deep areas of the thickened intima where collagen and elastin appeared as bundles. The photometric data of fibronectin supported these visual observations. Thus, fibronectin appeared early and disappeared later in the intima during the process of fatty streak initiation and maturation. These findings suggest that in hypercholesterolemia without mechanical endothelial injury, fibronectin may play an important role in an early process of atherogenesis.

Topics: Animals; Aorta; Arteriosclerosis; Collagen; Diet, Atherogenic; Disease Models, Animal; Elastin; Endothelium, Vascular; Fibronectins; Hypercholesterolemia; Immunohistochemistry; Male; Rabbits

In this paper we demonstrate that near infrared Fourier transform Raman spectroscopy provides unprecedented biochemical information about the extent of atherosclerosis in human aorta. In particular, elastin, collagen, cholesterol, cholesterol esters, lipids, carotenoids, and calcium apatite deposits all can be discerned by using this technique, permitting study of each stage in the disease process. Additionally, these moieties can be detected over 1.5 mm below the irradiated surface of the tissue, possibly allowing extraction of three-dimensional information about the histology of atherosclerotic plaques. We propose that this technique may be utilized for in situ optical histochemical analysis of atherosclerosis in particular and human disease in general.

Topics: Aorta; Apatites; Arteriosclerosis; Calcinosis; Calcium; Collagen; Elastin; Fourier Analysis; Humans; Lipids; Muscle, Smooth, Vascular; Reference Values; Spectrum Analysis, Raman

High resolution (125-microns lateral, 55-microns axial) images of 16 muscular (femoral) and 15 elastic (common carotid) human arteries were made in vitro with use of a prototype 45-MHz intravascular imaging system. Four distinct regions of scattering, excluding plaque, were identified in the ultrasound images corresponding histologically to the adventitia, media, thickened intima and elastic laminae, both internal and external. Arterial samples imaged under pressure and in a collapsed state underwent dimensional changes but exhibited similar levels of backscatter amplitude. All the elastic arteries displayed a prominent echogenic media, whereas all the muscular arteries displayed an echolucent media. Scattering from the internal elastic lamina in muscular arteries provided an excellent landmark for defining the location and extent of intimal thickening or plaque. In elastic arteries the internal elastic lamina could not be distinguished from the echogenic media; consequently, the boundary between the media and intimal layer was indistinct. Differences in the relative concentration and organization of collagen and elastin were found to provide a consistent explanation for the differences in scattering that were observed between individual layers within an artery as well as between muscular and elastic arteries.

Topics: Arteriosclerosis; Carotid Arteries; Carotid Artery Diseases; Collagen; Elastin; Femoral Artery; Humans; Pressure; Ultrasonography

Unstained frozen sections of normal and atherosclerotic human aorta and coronary artery were examined using histochemical and fluorescence microscopic techniques to identify the structures responsible for autofluorescence under 351 to 364 nm laser excitation. These structures included elastin and collagen in normal and atherosclerotic specimens, calcium deposits in calcified plaques, and granular or ring-shaped deposits histochemically identified as ceroid found in both calcified and non-calcified plaques. Qualitatively, both the color and intensity of ceroid autofluorescence differed greatly from that of elastin or collagen. The emission spectra of elastin, collagen, and ceroid were examined by microscopic spectrofluorimetry, and were found to differ significantly as well. When compared with spectra of elastin and collagen, spectra of ceroid were broader, shifted to the red, and were somewhat resistant to bleaching. We conclude that detection of laser-induced ceroid autofluorescence may aid in identifying plaques for laser ablation.

Topics: Angioplasty, Laser; Aorta; Arteriosclerosis; Ceroid; Collagen; Coronary Artery Disease; Coronary Vessels; Elastin; Fluorescence; Humans; In Vitro Techniques; Lasers; Microscopy, Fluorescence; Microscopy, Ultraviolet; Spectrometry, Fluorescence; Ultraviolet Rays

Healthy subjects of different ages and a group of atherosclerotic patients were tested for the presence of elastin-antielastin circulating immune complexes (CIC) in their sera. For the purpose the authors used a method based on sequential precipitation with rising concentrations of polyethylene glycol (PEG), dissociation of the precipitated CIC and further analysis of the resuspended precipitates for the presence of elastin derived peptides by an enzyme-linked immunosorbent assay (ELISA). Elastin-antielastin CIC were detected only in the serum of atherosclerotic patients and that of healthy subjects over 60. The elastin-antielastin CIC obtained from the serum of atherosclerotic patients were precipitated by higher PEG concentrations mainly and had a higher elastin content in comparison with those isolated from the serum of healthy persons over 60.

Topics: Adolescent; Adult; Aged; Antigen-Antibody Complex; Arteriosclerosis; Child; Child, Preschool; Diagnosis, Differential; Elastin; Enzyme-Linked Immunosorbent Assay; Female; Humans; Infant; Male; Middle Aged; Reference Values

Aortic elastins, isolated from 30 humans of different ages, were purified by alkaline extraction, and separated into two groups depending on the presence of atherosclerotic plaques and calcification (grades 0 and 1). It was confirmed that the severity of atherosclerosis increases significantly with age (P less than 0.001) and elastin content decreases with atherosclerosis (P less than 0.001). The hydrolysis of the aortic elastins using pancreatic porcine elastase (PPE) was studied. It was observed that increased elastolytic activities are connected with severity of atherosclerosis (P less than 0.001) and both Vm and Km apparent kinetic parameters are affected (P less than 0.001). Correlation tests have shown that enzymatic hydrolysis is significantly modified by cholesterol (P less than 0.05), calcium (P less than 0.001) and magnesium concentrations (P less than 0.01) but only cholesterol changes significantly Vm and Km parameters.

Topics: Adolescent; Adult; Aged; Aorta; Arteriosclerosis; Calcium; Cations, Divalent; Child; Child, Preschool; Cholesterol; Elastin; Humans; Infant; Infant, Newborn; Lipids; Magnesium; Middle Aged; Pancreatic Elastase; Phospholipids; Triglycerides

Markers of elastin metabolism were estimated in sera of children from families with a high risk of atherosclerosis (ATH). There was no statistically significant difference in the serum elastase-like activity between the groups studied. The concentration of elastin-derived peptides was statistically significantly elevated in the ATH group. Anti-elastin antibodies were found to be present in 73% of ATH children, while they circulated in 5% of control subjects only. Antibodies observed in the youngest ATH children were of the IgM type, suggesting the initial stage of the autoimmunization to elastin. The data obtained in this study may indicate an enhanced metabolism of elastin in ATH children.

Topics: Arteriosclerosis; Autoantibodies; Child; Child, Preschool; Elastin; Female; Humans; Male; Pancreatic Elastase; Risk Factors

Immunological and microbial factors may lead to the formation of atherosclerotic lesions. Cross immune reactions between aortic kappa-2-elastin and antisera against some antigens of Gram-negative bacteria--Salmonella and Escherichia coli--were studied using the dot-immunobinding assay. Positive results were obtained with antisera against Salmonella AO, BO, CO, EO, HM and Escherichia coli OK(A). Among immunological mechanisms leading to atherosclerosis cross immunoreactivity of aortic antigens with antimicrobial antibodies should be taken into consideration.

Topics: Animals; Antibodies, Bacterial; Antigens, Bacterial; Aorta; Arteriosclerosis; Cross Reactions; Elastin; Escherichia coli; Humans; Immunoblotting; Rabbits; Salmonella; Swine

Anti-elastin antibodies which seem to play an important role in atherogenesis were studied in serum of rabbits fed with a cholesterol-rich diet using the dot-immunobinding assay. These antibodies appeared only in rabbits of the experimental group after the sixth week of the experiment and a progressive rise in their titer was observed. The concentration of total serum cholesterol and the elastase-like activity in aorta which were determined additionally showed a statistically significant increase of both analyzed parameters in animals from the experimental group when compared to the controls. Anti-elastin antibodies seem to reflect an increased elastin turnover during the induction of experimental atherosclerosis.

Topics: Animals; Aorta; Arteriosclerosis; Autoantibodies; Cholesterol; Diet, Atherogenic; Elastin; Immunoblotting; Male; Pancreatic Elastase; Rabbits

Experimental immunization of rabbits with soluble porcine elastin was performed. A statistically significant decrease in the level of insoluble elastin in the aorta of the immunized animals was observed. Estimations of soluble collagen fractions showed the rise of both salt-soluble and acid-soluble collagen in the aorta of rabbits immunized with soluble porcine elastin.

Topics: Animals; Aorta; Arteriosclerosis; Collagen; Elastin; Immunization; Injections, Subcutaneous; Male; Rabbits

The biochemical mechanisms by which hypertension accelerates atherosclerosis and increases the risk of aortic aneurysm rupture are poorly understood. This study evaluates the effects of hypertension on aortic trace element concentrations and antioxidant status in tissue removed from 26 normotensive (NT) and 20 hypertensive (HT) patients. Twenty-seven of 46 patients (59%) had aneurysmal (AA), and 19 of 46 (41%) had occlusive disease (OD). Aortic iron concentrations were markedly higher in both OD and AA tissue compared with controls. A similar trend was observed with copper concentrations, with the highest elevations observed in HT AA tissues. No significant differences were observed in zinc concentrations, except that HT AA aorta had significantly lower zinc levels than either OD or control tissue. Aortic ascorbic acid concentrations in diseased aorta were lower than those of controls, but independent of blood pressure. Copper-zinc-superoxide dismutase activity was similarly reduced, with the lowest activity observed in diseased aorta from HT patients. Only HT AA aorta had significantly higher manganese-superoxide dismutase activity than controls. The aortas of patients with AA had significantly lower amounts of elastin and greater elastase activity than either controls or those with OD. However, the differences were independent of blood pressure. Hypertensive patients with OD and AA had 31% more and 27% less aortic collagen, respectively, than their NT counterparts (P less than 0.05). These data suggest that the reduction in aortic collagen and elastin in HT patients with AA compared with their NT counterparts may explain the larger size of aneurysms and predispose to their eventual rupture. Furthermore, the diminished antioxidant status associated with HT predisposes to lipid peroxidation, which contributes to the acceleration of these processes. Our studies were conducted in patients with established aortic aneurysmal and occlusive disease. Whether these observations are pertinent to the pathogenesis of AA and OD remains unclear and merits further study.

Topics: Antioxidants; Aorta; Aortic Aneurysm; Arteriosclerosis; Ascorbic Acid; Blood Pressure; Collagen; Copper; Elastin; Humans; Hypertension; Iron; Lipid Peroxidation; Male; Superoxide Dismutase; Trace Elements; Zinc

Topics: Adult; Aged; Aged, 80 and over; Arteriosclerosis; Collagen; Diabetic Angiopathies; Elastin; Glycosaminoglycans; Humans; Male; Middle Aged

We studied the effects of elastase on [3H]thymidine incorporation into aortic smooth muscle cells. When elastase was added to cultured aortic smooth muscle cells, [3H]thymidine incorporation was inhibited in a dose-dependent manner in the presence of fetal bovine serum. Elastase also inhibited this incorporation in cells treated with epidermal growth factor. Epidermal growth factor (50 ng/ml) stimulated thymidine incorporation, without elastase, but with the addition of 20 units/ml of elastase the incorporation was inhibited 70%. The incorporation of thymidine into cells treated with 50 ng/ml epidermal growth factor was also inhibited 50% by a low concentration of elastase (5 units/ml). These inhibitory effects on thymidine incorporation were also observed in cells stimulated with platelet-derived growth factor. Platelet-derived growth factor (20 units/ml) markedly stimulated thymidine incorporation into cells, and elastase inhibited its activity in a dose-dependent manner. These results suggest that elastase has the potential to prevent the development of atherosclerosis by inhibiting smooth muscle proliferation.

Topics: Animals; Aorta; Arteriosclerosis; Cell Division; Cells, Cultured; DNA; Elastin; Epidermal Growth Factor; Muscle, Smooth, Vascular; Pancreatic Elastase; Rats; Rats, Inbred Strains; Thymidine

This study was designed to test the hypothesis that severe atherosclerosis changes aortic compliance. Compliance of a vessel is defined as change in volume per unit change in pressure and is a measure of the stiffness or distensibility of the vascular wall. Part of the energy delivered by the left ventricle in systole is used to propel the blood forward into the aorta and part of it to distend the aorta and major vessels. During diastole, the arterial walls recoil and provide energy for propulsion of blood, thereby making blood flow continuous. It is known that Watanabe hereditary hyperlipidemic rabbits develop severe atherosclerosis beginning at 6 months of age. Compliance of the ascending thoracic aorta was studied angiographically in eight Watanabe hereditary hyperlipidemic rabbits of ages greater than 6 months and six normal lipidemic New Zealand white rabbits of ages greater than 6 months, used as controls. The normal New Zealand white rabbits had an average blood cholesterol of 27.4 mg/dL, SD = 13.8, and a regional compliance in the ascending aorta of 0.004 mL/mm Hg, SD = 0.002, compared to the Watanabe hereditary hyperlipidemic rabbits with a cholesterol of 583.1 mg/dL, SD = 162.7, and a compliance of 0.0022 mL/mm Hg, SD = 0.0015. These are significant differences (p less than .05). In addition, the histopathology of the aorta of the Watanabe hyperlipidemic rabbit compared to that of the controls showed a significant decrease in the number of medial lamellar elastin units, an indicator of the decreased elasticity of the blood vessel wall.

Topics: Angiography, Digital Subtraction; Animals; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Cholesterol; Elasticity; Elastin; Hyperlipoproteinemia Type II; Rabbits

Mononuclear phagocytes adhere to and penetrate the vessel wall endothelium and contact the subendothelial space prior to the development of the atherosclerotic plaque. In an attempt to model the early events of plaque development we used an elastin-rich, multicomponent, cell-derived matrix from neonatal rat aortic smooth muscle cells as a substratum for monocytes. Using this model, we show that human monocyte morphology and metabolism are markedly altered by the matrix substratum. When a mixed mononuclear cell population is seeded on matrix or plastic, only monocytes adhere to the matrix surface. In contrast, lymphocytes as well as monocytes adhere to the plastic surface. The matrix-adherent monocytes develop large intracellular granules and form extensive clusters of individual cells. Metabolically, these cells develop sodium fluoride resistant non-specific esterase activity and their media contain more growth factor activity and PGE2. Although total protein synthesis is equivalent in both cultures, the matrix contact induces an increase in specific proteins in the media. We also show that a purified alpha-elastin substratum induces some, but not all, of the monocyte changes seen when using the matrix substratum. Using the alpha-elastin substratum, there is selective adhesion of monocytes and increased growth factor activity, however, the cells are morphologically different from the matrix-adherent cells. Thus, the use of the smooth muscle cell-derived matrix, in conjunction with purified matrix components, serves as a model that can provide insight into the mechanisms of monocyte adhesion and stimulation by the matrix environment that exists in vivo. Such mechanisms may be particularly important in atherogenesis.

Topics: Animals; Aorta; Arteriosclerosis; Carboxylesterase; Carboxylic Ester Hydrolases; Cattle; Cell Adhesion; Cell Division; Cells, Cultured; Dinoprostone; Elastin; Extracellular Matrix; Fibroblasts; Humans; Monocytes; Muscle, Smooth, Vascular; Plastics; Protein Biosynthesis; Rats; Rats, Inbred Strains

The degradation of elastin during various pathological processes such as emphysema or arteriosclerosis was demonstrated by several investigators. In the present work, we adapted an ELISA technique for the determination of elastin peptide (EP) levels in human sera and plasma, in healthy and arteriosclerotic subjects. This test makes use of human aorta elastin hydrolyzed by a chemical procedure (kappa-elastin) instead of EP produced by pancreatic or leukocyte elastase. Polyclonal antibodies to this antigen were obtained in rabbits. The indirect ELISA procedure is sensitive, specific and reproducible. No correlation could be demonstrated between EP level and anti-EP antibody concentration of IgG or IgM types determined in the same serum samples. These antibodies did not interfere with EP determinations. EP concentration did not change with age in control subjects. In obliterative arteriosclerosis of the legs and in type IIb hyperlipoproteinemia, EP levels showed a marked increase, while in hypertension, ischemic heart disease and diabetes mellitus, the increase was moderate. In stroke, only slight changes were observed. In type IV hyperlipoproteinemia, EP levels were lower than in controls.

Topics: Adult; Age Factors; Aged; Aorta; Arteriosclerosis; Cerebrovascular Disorders; Coronary Disease; Diabetes Mellitus; Elastin; Enzyme-Linked Immunosorbent Assay; Humans; Hydrolysis; Hyperlipoproteinemias; Hypertension; Immunoglobulin G; Immunoglobulin M; Leg; Middle Aged; Peptides; Sensitivity and Specificity

Intravascular ultrasound imaging is a new method in which high resolution images of the arterial wall are obtained with use of a catheter placed within an artery. An in vitro Plexiglas well model was used to validate measurements of the luminal area, and an excellent correlation was obtained. One hundred thirty segments of fresh peripheral arteries underwent ultrasound imaging and the findings were compared with the corresponding histopathologic sections. Luminal areas determined with ultrasound imaging correlated well with those calculated from microscopic slides (r = 0.98). Three patterns were identified on the ultrasound images: 1) distinct interface between media and adventitia, 2) indistinct interface between media and adventitia but different echo density layers, and 3) diffuse homogeneous appearance. The types of patterns depended on the relative composition of the media and adventitia. Calcification of intimal plaque obscured underlying structures. Atherosclerotic plaque was readily visualized but could not always be differentiated from the underlying media.

Topics: Adult; Aged; Aged, 80 and over; Arteries; Arteriosclerosis; Calcinosis; Collagen; Elasticity; Elastin; Humans; Middle Aged; Models, Structural; Muscle, Smooth, Vascular; Necrosis; Reference Values; Ultrasonography

White Carneau pigeons have previously been shown to be genetically susceptible to the development of spontaneous atherogenesis. The severity of development of atheromatous lesions is considerably greater than a more resistant breed of Show Racer pigeons. Analysis of levels of total hydroxyproline and isodesmosine in the thoracic aorta and celiac bifurcation of prelesion, six-week-old White Carneau and Show Racer pigeons, revealed an increased accumulation of total collagen and cross-linked elastin in the White Carneau arterial tissue. Using dot blot hybridization, measurements of steady state levels of several mRNAs in total RNA extracted from pigeon aortic tissue were also determined. While the increased deposition of extracellular matrix proteins was paralleled by a significantly greater recovery of mRNAs coding for pro alpha 1(1) collagen and elastin, in RNA extracted from White Carneau aortal tissue, increased recovery of mRNAs coding for an intracellular protein, gamma-actin were also observed in White Carneau aortal tissue. No differences in steady state levels of mRNAs coding for pro alpha 1(1) collagen and elastin were observed in RNA extracted from pigeon liver, suggesting a tissue specific increase in the mRNAs coding for these connective tissue proteins in aorta. A markedly reduced cell population however, was responsible for this overall increase in biosynthetic activity in White Carneau pigeon aortic tissue. This was demonstrated by a reduced cell count and by the recovery of reduced levels of total DNA in the thoracic aorta and celiac bifurcation of the White Carneau pigeon. The cell population in White Carneau aortic tissue exhibits therefore a markedly different phenotype with respect to a capacity for the biosynthesis of extracellular and intracellular proteins.

Topics: Actins; Animals; Aorta, Thoracic; Arteriosclerosis; Celiac Artery; Collagen; Columbidae; DNA; Elastin; Extracellular Matrix Proteins; Nucleic Acid Hybridization; Phenotype; RNA, Messenger

Ultraviolet excited laser induced fluorescence (LIF) was studied in normal and atherosclerotic human arterial wall in vitro. Using excitation wavelengths from 306 to 310 nm, two distinct emission bands were observed in the LIF of both normal and pathologic aorta: a short wavelength band, peaking at 340 nm emission, which was attributed to tryptophan; and a long wavelength band, peaking at 380 nm emission, which was assigned to a combination of collagen and elastin. The intensity of the short wavelength band was quite sensitive to the choice of excitation wavelength, while the long wavelength band was not, so that the relative contributions of the bands could be controlled by the precise choice of excitation wavelength. A valley in the spectra at 418 nm was attributed to fluorescence reabsorption by oxy-hemoglobin. By using 308 nm excitation to observe emission simultaneously from both the short and long wavelength bands, normal and atherosclerotic aorta were spectrally distinct. Two LIF emission intensity ratios were defined to characterize both the relative tryptophan fluorescence content as well as the ratio of elastin to collagen fluorescence in each spectrum. The differences in these two emission ratios among the various histologic tissue types correlated qualitatively with the histologic and biochemical compositions of these tissues. By combining these parameters in a binary classification scheme, normal and atherosclerotic aorta were correctly distinguished in 56 of 60 total cases. Furthermore, atherosclerotic plaques, atheromatous plaques, and exposed calcifications could be classified individually with sensitivities/predictive values of 90%/90%, 100%/75%, and 82%/82%, respectively.

Topics: Aorta; Aortic Diseases; Arteriosclerosis; Collagen; Elastin; Humans; In Vitro Techniques; Lasers; Spectrometry, Fluorescence; Tryptophan

Alpha-elastin of human aorta was investigated by an enzyme-linked immunosorbent assay (ELISA) on the material isolated from aborted human fetuses and healthy subjects killed by accident, assigned to 7 age groups. Samples up to the age of 55 were taken only from regions without detectable changes in the arterial wall, in the 60-75-year age group--both from normal areas and atherosclerotic plaques of the same aortas. An immune serum against alpha-elastin isolated from the normal aortic areas of a 61-year-old subject was produced in sheep. Testing with this serum showed the existence of some antigenic changes in the elastins from different age groups. A prevalence of the species-specific antigenic determinants was observed in alpha-elastin from fetal aorta while in alpha-elastin from the atherosclerotically altered human aorta the cross-reacting antigenic determinants prevailed in its antigenic structure.

Topics: Adolescent; Adult; Aged; Aging; Animals; Aorta; Arteriosclerosis; Chickens; Child; Child, Preschool; Cross Reactions; Elastin; Enzyme-Linked Immunosorbent Assay; Epitopes; Fetus; Humans; Immune Sera; Infant; Middle Aged

The observation that laser-induced fluorescence (LIF) spectra of atherosclerotic and normal artery are different has been proposed as the basis for guiding a "smart" laser angioplasty system. The purpose of this study was to investigate the causes of this difference in LIF. Helium-cadmium laser-induced (325 nm) fluorescence was recorded from pure samples of known constituents of normal and atherosclerotic artery including collagen, elastin, calcium, cholesterol, and glycosaminoglycans. Similarities between the LIF spectra of atherosclerotic plaque and collagen and normal aorta and elastin were noted. LIF spectroscopy was then performed on specimens of atherosclerotic aortic plaque (n = 9) and normal aorta (n = 13) and on their extracted lipid, collagen, and elastin. Lipid extraction did not significantly alter atherosclerotic plaque or normal aortic LIF, suggesting a minor contribution of lipid to arterial LIF. The LIF spectra of normal aorta wall was similar to the spectra of the extracted elastin, whereas the LIF spectra of atherosclerotic aortic plaque was similar to the spectra of the extracted collagen. These observations are consistent with the reported relative collagen-to-elastin content ratio of 0.5 for normal arterial wall and 7.3 for atherosclerotic plaque. A classification algorithm was developed to discriminate normal and atherosclerotic aortic spectra based on an elastin and collagen spectral decomposition. A discriminant score was formed by the difference of elastin and collagen (E-C) coefficients and used to classify 182 aortic fluorescence spectra. The mean E-C value was +0.83 +/- 0.04 for normal and -0.48 +/- 0.07 for atherosclerotic aorta (p less than 0.001). Classification accuracy was 92%.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Algorithms; Angioplasty, Balloon; Aorta; Aortic Diseases; Arteriosclerosis; Collagen; Elastin; Humans; Lasers; Lipid Metabolism; Microscopy, Fluorescence

Fluorescence spectroscopy is a promising new technique for discrimination of normal and atherosclerotic arterial tissues. It has been suggested that this technique be used as a guidance system for laser angiosurgery catheters; however, irradiation by 476-nm light can change the spectroscopic properties of arterial tissue. We present studies that establish intensity levels and exposure times at which alterations in tissue spectral properties are minimal. We also investigate the nature of spectral alterations following exposure of normal human aorta to high intensities of 476-nm laser light. Changes in laser-induced fluorescence (LIF) are characterized by two prominent features: the peak fluorescence intensity decreases permanently, and the fluorescence lineshape changes in a largely reversible way. We relate these changes to alterations in individual tissue chromophores: permanent changes in absolute fluorescence intensity are due to irreversible changes in tissue fluorophores, reversible changes in fluorescence lineshape are due alterations in tissue absorbers. A simple kinetic model is used to describe the decrease in absolute fluorescence intensity.

Topics: Aorta; Arteriosclerosis; Collagen; Elastin; Humans; Laser Therapy; Muscle, Smooth, Vascular; Scattering, Radiation; Spectrometry, Fluorescence

These experiments were designed to determine if male New Zealand white rabbits made mildly hypertensive (20-30 mm Hg increase) with bilateral renal artery clips developed more or less sudanophilic lesions than controls, and if the animals responded differently if hypercholesterolemia was produced soon (one week) or late (eight weeks) after the animals were operated on. Both groups received the diet of 2% cholesterol and 6% corn oil for six weeks. We also studied the distensibility of the carotid artery to determine if altered elastic behaviour played a role in lesion development. The experiments showed that the acute hypertensive group developed most lesions (by area), but that the lesions in all groups had the same shape and location. The carotid arteries from the chronic hypertensives were least distensible, and most of the changes appeared to be in the elastance of collagen. The blood pressure actually dropped slightly in the chronic shams after the diet was started. These experiments suggest that, at least, in the rabbit, the duration of the hypertension may determine how the arterial wall responds to hypercholesterolemia. They show that mild hypertension, like hypercholesterolemia, alters the rate at which lesions develop, rather than altering their distribution. The changes do not appear to be related to altered distensibility.

Topics: Analysis of Variance; Animals; Arteriosclerosis; Azo Compounds; Carotid Arteries; Collagen; Elasticity; Elastin; Hypercholesterolemia; Hypertension; Male; Rabbits; Stress, Mechanical

This paper describes a general model of tissue fluorescence which can be used both to: 1) determine chemical and physical properties of the tissue, and 2) design an optimal algorithm for clinical diagnosis of tissue composition. This model is based on a picture of tissue as a single, optically thick layer, in which fluorophores and absorbing species are homogeneously distributed. As a specific example, the model is applied to the laser induced fluorescence (LIF) of normal and atherosclerotic human aorta using 476 nm excitation. Methods for determining the relevant attenuation and fluorescence lineshapes are detailed, and these lineshapes are used to apply the model to data from 148 samples. The model parameters are related to the concentrations of the major arterial chromophores: structural proteins, hemoglobin and ceroid. In addition, the model parameters are used to derive diagnostic algorithms for the presence of atherosclerosis. Utilizing a binary classification scheme, the presence or absence of pathology was determined correctly in 88 percent of cases.

Topics: Algorithms; Aorta; Arteriosclerosis; Collagen; Elastin; Humans; Lasers; Microscopy, Fluorescence

We adapted a highly sensitive and reproducible ELISA technique for the determination of anti-elastin peptide antibodies of IgG type AEAb-IgG) and IgM type AEAb-IgM) in human sera. The determination was performed in the sera of 265 normal and diseased persons. The pathologies studied included obliterative arteriosclerosis of the legs, ischemic heart disease, stroke, diabetes mellitus, type IIb and IV hyperlipoproteinemia and hypertension. No clearcut correlation could be found between AEAb and age. In contrast, in arteriosclerotic patients and especially in obliterative arteriosclerosis of the legs and ischemic heart disease, the concentration of AEAb-IgG was significantly increased. The AEAb-IgM showed no change in the studied diseases. Both types of AEAb were decreased in type IV hyperlipoproteinemia. Anti-elastin antibodies may be involved in the pathomechanisms of the above diseases and the determination of antibody concentrations may be of some help in obliterative arteriosclerotic diseases.

Topics: Adult; Aged; Antibodies; Arteriosclerosis; Cerebrovascular Disorders; Coronary Disease; Diabetes Mellitus; Elastin; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hyperlipoproteinemia Type II; Hyperlipoproteinemia Type IV; Male; Middle Aged; Peptides

Topics: Adolescent; Adult; Aged; Antibodies; Antigen-Antibody Complex; Arteriosclerosis; Autoradiography; Child; Child, Preschool; Elastin; Electrophoresis, Polyacrylamide Gel; Humans; Infant; Middle Aged; Reference Values; Sensitivity and Specificity

Previous studies on the pathogenesis of abdominal aortic aneurysms have shown both elastase-like activity in the aortic wall and a decreased elastin content. The present study, using specific radioimmunoassays for pancreatic elastase 2 (IRE2) and cationic trypsin(ogen) (IRCT), investigates the concentrations of these proteases which are known to circulate in blood, in abdominal aortic aneurysms. Aortic specimens were obtained from 32 patients with aneurysms and 21 patients with atherosclerotic occlusive disease. Aortic tissue, obtained at autopsy from young adults, served as controls. Elastase-like activity was 300% and 800% higher, respectively, in aortic homogenates from aneurysms in comparison to occlusive disease and control aortic tissue. This was associated with 1.4-fold higher level of IRE2 and 2.7-fold higher levels of IRCT as compared to occlusive disease. Although there was no significant difference in the aortic collagen concentration among all 3 groups, the elastin content of aneurysmal aorta was 85% and 74% lower, respectively, in comparison to control and occlusive aorta. The results of this investigation demonstrate the presence of pancreatic elastase 2 and cationic trypsin(ogen) in abdominal aortic aneurysmal tissue and suggest that circulating pancreatic proteases contribute to the pathophysiology of aneurysms of the infrarenal aorta.

Topics: Adult; Aged; Aorta, Abdominal; Aortic Aneurysm; Arteriosclerosis; Elastin; Humans; In Vitro Techniques; Middle Aged; Pancreatic Elastase; Radioimmunoassay; Risk Factors; Smoking; Trypsinogen

Immunization of rabbits with elastin peptides prepared from purified bovine ligamentum nuchae elastin produces calcified arteriosclerotic lesions and fragmentation of elastic lamellae. Simultaneous administration of porcine calcitonin largely prevents the development of lesions. Experiments were carried out to clarify the mechanisms involved in the development of lesions as well as those involved in the preventive effect of calcitonin. Control experiments were carried out using bovine serum albumin (BSA) as antigen. Circulating antibodies and soluble immune complexes increased steadily in the sera of animals immunized with elastin peptides or BSA. The cellular immune reaction was weak as assessed by [3H]thymidine incorporation into lymphocytes in the presence of antigen or phytohemagglutinin. Arterial lesions appeared only in the animals immunized with elastin peptides, not in those immunized with BSA. Ion flux measurements were also carried out on strips of aorta obtained from immunized and control animals. Immunization with elastin peptides significantly increased the ouabain-insensitive 22Na+ efflux, the 86Rb efflux (indicator of K+ efflux), and the 45Ca2+ influx. Simultaneous calcitonin administration prevented the increase in Ca2+ influx but did enhance passive permeability to Na+ and K+ as well as the sodium pump. When calcitonin was administered without immunization, it decreased arterial smooth muscle permeability to Na+ and K+ and also decreased the basal Ca2+ influx. It is concluded that the pathological modifications of the arterial wall triggered by immunization with elastin peptides is at least partly mediated by the effect of antielastin antibodies and immune complexes on the ion permeability of arterial smooth muscle. Prevention of the increased Ca2+ influx by calcitonin is probably a key effect in the prevention of the development of lesions. The fact that calcitonin alone can modify the ion permeability of arterial smooth muscle suggests that this hormone may play a role in the regulation of vascular homeostasis.

Topics: Animals; Antigen-Antibody Complex; Aorta; Arteriosclerosis; Calcitonin; Cell Membrane Permeability; Elastin; Immunity, Cellular; Immunization; Ion Channels; Male; Muscle, Smooth, Vascular; Rabbits; Serum Albumin, Bovine

Topics: Adult; Animals; Arteriosclerosis; Child; Child, Preschool; Copper; Elastin; Female; Fetus; Humans; Infant; Infant, Newborn; Male; Mammary Arteries; Menkes Kinky Hair Syndrome; Muscle, Smooth, Vascular; Myocardial Revascularization; Pregnancy; Saphenous Vein; Swine; Thoracic Arteries

In order to further investigate the role of the immune system in the arteriosclerotic process, we investigated the anti-elastin peptide antibodies (AEAb) of the IgG and IgM types by DOT immunobinding assay in the sera of patients suffering from various arteriosclerotic diseases. In total 232 control and pathological sera were studied. In obliterative arteriosclerosis of the legs 90%, ischemic heart disease 67% and hypertension 60% of sera were positive for AEAb of the IgG type independent of age. In the case of diabetes mellitus, however, the duration of the disease was determinant. In rheumatoid arthritis, the results were negative. No clear-cut positivity could be demonstrated in stroke patients either. These results indicate that AEAb can be detected in some diseases and DOT appears to be an appropriate method for the AEAb screening in various diseases.

Topics: Adult; Age Factors; Aged; Arteriosclerosis; Arthritis, Rheumatoid; Coronary Disease; Diabetes Mellitus; Elastin; Female; Humans; Hypertension; Immunoglobulin G; Immunoglobulin M; Immunosorbent Techniques; Male; Middle Aged; Peptide Fragments

A rapid, sensitive high-performance liquid chromatographic method has been developed for the determination of desmosine (DES) and isodesmosine (IDE), the specific cross-linking amino acids of elastin, in the tissue hydrolysates of rats. DES and IDE in the hydrolysate samples were separated on a C18 column using 0.1 M phosphate buffer-acetonitrile (2.8:1) containing 20 mM sodium dodecyl sulphate (final pH 4.5) followed by detection at 270 nm. The recoveries of the added standards of DES and IDE from the aorta hydrolysate samples were 99.6 +/- 2.7% and 98.4 +/- 1.8%, respectively (n = 10). At DES and IDE concentrations of 2 micrograms/ml, within- and between-run precisions were 1.11-1.85% and 0.55-1.24%, respectively. The detection limits of DES and IDE were 0.1 microgram/ml with a 50-microliter injection at a signal-to-noise ratio of 3. The method was successfully applied to a study of the alteration of DES and IDE contents (i.e. elstin contents) in the tissues of rats treated with beta-aminopropionitrile and an atherogenic diet. A negative correlation between the contents of these amino acids and of cholesterol was noted in the atherosclerotic aorta.

Topics: Amino Acids; Animals; Arteriosclerosis; Chromatography, High Pressure Liquid; Desmosine; Diet, Atherogenic; Elastin; Hydrogen-Ion Concentration; Isodesmosine; Liver; Lung; Male; Muscle, Smooth, Vascular; Rats; Rats, Inbred Strains

The level of the circulating elastin-derived peptides (CEDP) in the serum is believed to reflect the activity of the degradation of the elastic structures. This paper reports a new method, based on the 'sandwich' version of the enzyme-linked immunosorbent assay (ELISA), for the detection and quantification of CEDP in human serum. By this method we investigated the age-related changes in their level among healthy subjects within the age range of 1 and 75 years and among atherosclerotic subjects aged 50 to 75 years. The highest level of CEDP was found in the serum of the atherosclerotic patients, and the lowest, among the healthy subjects between 18 and 50 years of age.

Topics: Adolescent; Adult; Aged; Aging; Animals; Arteriosclerosis; Child; Child, Preschool; Elastin; Enzyme-Linked Immunosorbent Assay; Humans; Infant; Male; Middle Aged; Peptides; Rabbits; Reference Values; Sheep

Exposure of smooth muscle cells cultured on plastic or glass to hyperlipidemic serum did not result in the formation of foam cells. Since elastin binds serum lipids, and vascular smooth muscle cells are normally closely associated with elastin, we investigated the effects of an elastin substrate on lipid metabolism and on the accumulation of lipid vacuoles by rabbit aortic smooth muscle cells in culture. When cells were grown in plastic petri dishes, cholesteryl ester synthesis, as measured by [14C]oleate incorporation into cholesteryl esters, was 3 times greater in rabbit hyperlipidemic serum (HLS) than in normolipemic serum (NLS) (P less than 0.001). For cells of the same subculture grown on the elastin substrate, the synthetic rate was 6-fold greater in HLS compared to NLS (P less than 0.005). The cells grown on the elastin membranes in the presence of HLS contained large numbers of Oil red O stainable lipid vacuoles and resembled foam cells, while those grown in petri dishes and exposed to HLS showed only an occasional cell containing a few vacuoles. Pre-incubation in lipoprotein-deficient serum markedly enhanced the stimulatory effect of HLS on cholesteryl ester synthesis for cells growing in plastic petric dishes but had much less stimulatory effect on the cells growing on elastin membranes. These studies indicate that close association with elastin modulates the response of smooth muscle cells to hyperlipidemia and suggest a role for elastin in the formation of foam cells of smooth muscle origin during atherogenesis.

Topics: Animals; Aorta, Thoracic; Arteriosclerosis; Binding Sites; Cells, Cultured; Cholesterol Esters; Elastin; Foam Cells; Hyperlipidemias; Macrophages; Muscle, Smooth, Vascular

Smooth muscle cells derived from the media of adult rat aorta were grown on elastin membranes for up to 3 weeks in cell culture. Cell degeneration was evident by the 4th day and increased with time. At the end of the experiment necrotic and calcified areas were prominent. The basic feature of cell degeneration was dissolution of myofilaments; the disintegrating cytoplasm usually contained numerous glycogen granules. Increased electron density of the mitochondrial matrix and fat globules were seen and nuclei showed dilution of chromatin or pyknosis. Abundant cellular debris, vesicular structures and microfibrils were found in the extracellular space.

Topics: Animals; Aorta, Thoracic; Arteriosclerosis; Cells, Cultured; Elastin; Microscopy, Electron; Microscopy, Electron, Scanning; Muscle, Smooth, Vascular; Rats

A modified version of the enzyme-linked immunosorbent assay (ELISA), utilising human insoluble aortic elastin, was used for determination of anti-elastin antibodies in serum from normal and atherosclerotic subjects. The age-related changes in their level among healthy persons were investigated. Anti-elastin antibodies were found in all the tested human sera, showing the highest level at the age of 18-20 and the lowest at the age over 60 and especially among atherosclerotic patients. The possible role of the immune system in the turnover of elastin is discussed.

Topics: Adolescent; Adult; Age Factors; Aged; Arteriosclerosis; Autoantibodies; Child; Child, Preschool; Elastin; Enzyme-Linked Immunosorbent Assay; Female; Humans; Male; Middle Aged

Human monocytes have been shown to penetrate the endothelial layer of large blood vessels and to adhere to the subendothelial basement membrane. To determine the active components of this process, we have studied the ability of monocytes to adhere to isolated components of the subendothelial matrix. Using a quantitative dot-blot adhesion assay, we find that monocytes adhere preferentially to immobilized laminin and elastin. The monocytes adhere less well to fibronectin and bind poorly or not at all to collagen types I and IV, or to heparan sulfate. Monocyte binding to elastin requires an intact, crosslinked molecule as no binding was observed to soluble, acid-alcohol elastin extracts, to pepsin or elastase digests of elastin, to tropoelastin monomer, or to desmosine/isodesmosine crosslinks. Similar binding profiles to elastin, laminin, and fibronectin were seen with the established human leukocyte cell line U937. The promyelocytic cell line HL60 adhered equally well to laminin but showed slightly reduced adhesion to elastin when compared with the fresh monocytes or U937 cells. Freshly isolated human erythrocytes did not demonstrate significant adhesion to fibronectin, laminin, or elastin.

Topics: Arteriosclerosis; Blood Vessels; Cell Adhesion; Cells, Cultured; Elastin; Endothelium; Extracellular Matrix; Fibronectins; Humans; Laminin; Monocytes

The carotid artery lesions of atherosclerotic cynomolgus monkeys treated with cholestyramine and studied with scanning electron microscopy appeared to be less bulging and largely covered by endothelial cells. With transmission electron microscopy these lesions showed an evident disappearance of cells and of extra- and intracellular lipid; a marked relative increase of fibrous material in the intercellular matrix, chiefly collagen and elastin fibers, was noted.

Topics: Animals; Arteriosclerosis; Carotid Arteries; Cholestyramine Resin; Collagen; Diet, Atherogenic; Elastin; Macaca; Macaca fascicularis; Male; Microscopy, Electron; Microscopy, Electron, Scanning; Time Factors

Topics: Adolescent; Adult; Aging; Antigens; Aorta; Arteriosclerosis; Elastin; Fetus; Humans; Middle Aged

When human citrated plasma is dialysed against a phosphate buffer containing Ca++, citrate anions are removed, thrombin is generated and soluble fibrinogen derivatives (fibrin monomers and/or soluble fibrin polymers) are formed. These derivatives are able to combine with human or bovine elastin to form a very stable addition product or adduct. The formation of the adduct is dependent on time, Ca++ and thrombin concentrations.

Topics: Animals; Arteriosclerosis; Calcium; Cattle; Citrates; Citric Acid; Dialysis; Elastin; Fibrinogen; Humans; In Vitro Techniques; Solubility; Thrombin; Thrombosis

Topics: Animals; Aorta; Arteriosclerosis; Collagen; Elastin; Glycosaminoglycans; Male; Rabbits; Thymosin

Atherosclerosis was induced in growing chickens by the administration of a diet containing elevated levels of cholesterol and vitamin D3. The effect of this diet on the accumulation of insoluble elastin and the synthesis of soluble and insoluble elastin in the thoracic aortas of these animals was measured. Although the diet resulted in significant increases in levels of cholesterol, 25-OH vitamin D3 and calcium in plasma, increased levels of cholesterol and calcium in aortic tissue, and histological evidence of aortic lipid deposition, there were no detectable differences between experimental and control animals in either the rate or the time course of accumulation of total insoluble elastin in the thoracic aorta, or in the rate and time course of synthesis of soluble and insoluble elastin. These data suggest that, at least in this model, any effect of atherosclerosis on aortic elastin production must be either small or so localized as to be not measurable by the methods used.

Topics: Animals; Animals, Newborn; Aorta; Arteriosclerosis; Calcifediol; Calcium; Chickens; Cholecalciferol; Cholesterol; Diet; Elastin; Female

Rabbits immunized with kappa elastin produced arteriosclerosis and antibodies that bound to target-structures (elastic fiber sheaths, endothelial and smooth muscle cells). These antibodies were cytotoxic for cultured rabbit or rat arterial smooth muscle cells. Absorption of the antielastin antiserum with pig aorta or human serum glycoproteins inhibited its binding to target-structures and suppressed its in vitro cytotoxicity. These data are discussed.

Topics: Animals; Antibody-Dependent Cell Cytotoxicity; Aorta; Arteriosclerosis; Cells, Cultured; Elastin; Glycoproteins; Humans; Immunoenzyme Techniques; Rabbits; Rats; Rats, Inbred Strains; Swine

Topics: Animals; Arteriosclerosis; Calcium; Cholesterol; Collagen; Diet, Atherogenic; Diphosphonates; Elastin; Etidronic Acid; Humans; Lanthanum; Macaca fascicularis; Male; Muscle, Smooth, Vascular; Piperazines; Rabbits

Female rabbits on an atherogenic diet were treated with cottonseed oil (control), tamoxifen, testosterone, or progesterone. After 10 weeks the rabbits were killed, the aortas quickly removed, graded for atherosclerosis, and incubated with [14C]proline to determine collagen and elastin synthesis. Rabbits treated with testosterone and progesterone had the greatest degree of atherosclerosis, the highest DPM in hydroxyproline of collagen and elastin, and the greatest accumulation of collagen and elastin in the aorta. Tamoxifen-treated rabbits had less incorporation of radioactivity. In separate experiments aortas of similarly treated rabbits were analyzed for estradiol and progesterone receptor density. These receptors were found to be present, and progesterone and testosterone administration caused a translocation of progesterone receptors from cytosol to nucleus. Results are consistent with the hypothesis that sex hormones can affect the development of atherosclerosis through a direct effect of the hormones on arterial wall to alter collagen and elastin synthesis, the effect being mediated through hormone receptors in the wall.

Topics: Animals; Arteries; Arteriosclerosis; Body Weight; Cholesterol; Collagen; Elastin; Female; Gonadal Steroid Hormones; Progesterone; Rabbits; Receptors, Estradiol; Receptors, Progesterone; Tamoxifen; Testosterone

A comprehensive morphobiochemical study of aortal lipoidosis and a study of the serum lipid content were conducted in children. Fifty aortas from children who had died as a result of accidents and diseases at the age of 4 to 16 and the blood serum from 350 healthy children served as the material for the investigation. The development of aortal lipid spots in children was shown to be associated with lipid accumulation, particularly cholesterin ethers in smooth muscle cells of the intima. Lipid accumulation was accompanied by the proliferation of smooth muscle cells, phenomena of enhanced collagen- and elastin formation in parallel with the destruction of elastic fibers and membranes expressed quantitatively in an increased content of collagen and a decreased content of elastin. Aortal lipid spots were inhomogeneous depending on children age. "Juvenile" and "intermediate" types were singled out. Lipid spots of the "intermediate" type found in children over 10 may be of certain importance in the development of atherosclerotic arterial changes. There was no correlation between the frequency of hypercholesterinemia and the frequency of aortal lipoidosis in children.

Topics: Adolescent; Aorta; Arteriosclerosis; Child; Child, Preschool; Collagen; Elastin; Female; Histocytochemistry; Humans; Lipid Metabolism; Male; Muscle, Smooth, Vascular; Time Factors

The overall three-dimensional architecture of elastic tissue in early atherosclerotic lesions of the rat aorta was studied using scanning electron microscopy (SEM) after hot-formic acid extraction followed by a freeze-drying method. These lesions were induced by feeding the rats a diet containing 2% cholesterol, 0.5% cholic acid and 0.2% methylthiouracil. SEM revealed two types of alterations in the elastic tissue; one was an increase in the dome-like elastic lamina with few fenestrations that might be due to the reduplication of the internal elastic lamina (IEL), and the other was an increase in fibrous elastin, generally oriented longitudinally in the intima. The former was discussed with respect to its barrier function to such macromolecules as fibrinogen and low density lipoprotein (LDL), and was assumed to be a structure related to prevention of early atherosclerotic lesions.

Topics: Animals; Aorta, Thoracic; Arteriosclerosis; Elastic Tissue; Elastin; Hypercholesterolemia; Male; Microscopy, Electron, Scanning; Rats; Rats, Inbred Strains; Time Factors

Studies were performed in vitro on cylindrical segments of 56 canine common carotid arteries, 32 human external iliac arteries, nine internal iliac arteries, and ten common iliac arteries, using purified elastase and purified collagenase. Treatment with elastase caused the canine vessels to dilate but to remain intact. Similar results were obtained with the human vessels, except that treatment with elastase caused only slight dilation. All canine and human vessels treated with collagenase ruptured. We concluded that wall integrity depends on intact collagen rather than elastin. Comparison between external iliac arteries and internal and common iliac arteries showed that the latter vessels exhibited dramatically greater dilatation and compliance changes after treatment with collagenase. This finding corresponds to the greater tendency of aneurysms to develop in internal and common iliac arteries.

Topics: Aneurysm; Animals; Arteries; Arteriosclerosis; Carotid Arteries; Collagen; Dilatation, Pathologic; Dogs; Elastin; Humans; Iliac Artery; In Vitro Techniques; Microbial Collagenase; Middle Aged; Pancreatic Elastase

Topics: Adolescent; Adult; Aged; Aging; Aorta; Arteriosclerosis; Child; Child, Preschool; Collagen; Elastin; Histocytochemistry; Humans; Infant; Infant, Newborn; Middle Aged

The chemical composition of the aorta, carotid, coronary and cerebral arteries of the cynomolgus monkey was determined during the induction and 'regression' of atherosclerosis. The feeding of a 2% cholesterol and 10% butter diet for 6 months resulted in extensive and severe atherosclerosis involving the aorta, carotid and coronary arteries. The involvement of these vessels was reflected by increases in arterial weight and chemical content of cholesterol, collagen, elastin, glycosaminoglycans (GAGs) and calcium. The cerebral arteries, which showed no atherosclerotic involvement, likewise showed no significant changes in weight and composition. During the 12-month regression period marked changes in the chemical composition of the involved arteries occurred and these included further increases in the collagen, GAG and calcium content of the vessels and decreases in the free and esterified cholesterol content. These changes were consistent with the gross and microscopic findings which revealed that during regression the pre-established lesions had not decreased in size but had become more fibrotic and calcified while the number of foam cells and amount of lipid contained in the lesion had decreased. During induction and regression, much of the cholesterol contained in the involved vessels appeared to be present in a crystalline form as indicated by the appearance of cholesterol clefts in the lesions. Aortic collagen was not altered with respect to amino acid composition and behavior in acrylamide gels throughout the study. However, elastin prepared by hot alkali treatment from diseased vessels, showed minor changes in amino acids during induction and marked changes during regression presumably due to the binding of glycoproteins to the elastin. The GAG composition of the involved arteries did not change during induction, whereas during regression the percent dermatan sulfate increased while the percent of heparan sulfate decreased. The over-all findings are consistent with the concept that the interaction of the connective tissue proteins with the GAGs, lipoproteins and calcium of the artery plays an important role in the development and regression of advanced atherosclerotic disease.

Topics: Animals; Arteries; Arteriosclerosis; Body Weight; Calcium; Cholesterol; Collagen; Connective Tissue; Coronary Vessels; Elastin; Glycosaminoglycans; Macaca fascicularis; Male

The mechanism of in vitro complex formation between plasma low density lipoproteins (LDL) and arterial elastin was studied. Rosette formation and decreased binding of the chemically modified LDL suggested that the intact protein moiety of lipoproteins was essential for the transfer of lipids from LDL to elastin. However, subsequent treatment of the elastin-LDL complex with trypsin removed the greater part of the lipoprotein protein but not the transferred cholesterol, indicating that the protein moiety of the lipoprotein did not take part in the retention of lipids on the elastin. In view of the observed effects of pH, ionic strength, various types of detergents and polarity of elastin preparations, it appears that the charged groups of the protein moiety of lipoproteins and the hydrophobicity of elastin proteins may play important parts in the binding of lipoproteins to arterial elastin.

Topics: Aorta; Apolipoproteins; Arteriosclerosis; Cations, Divalent; Cholesterol; Detergents; Elastin; Humans; Hydrogen-Ion Concentration; Lipoproteins, LDL; Osmolar Concentration; Protein Binding; Rosette Formation; Trypsin

The present paper deals with the particular behavior of the complexes formed between pancreatic elastase and seric inhibitors in the Pig, when they were set in contact with homologous elastin. The previously known values of dissociation constants of alpha 1-antiprotease-elastase and alpha 2-macroglobulin-elastase complexes indicated they were very stable and almost irreversible. Nevertheless, our results suggest that, when the overall complexes between porcine pancreatic elastase and seric inhibitors were isolated in non drastic conditions, they might develop an elastolytic activity against elastin fibers. This result is important as regards atherosclerosis--in Human--where a destruction of elastin is involved at a early stage of the disease.

Topics: Animals; Aorta; Arteriosclerosis; Elastin; Humans; Kinetics; Pancreas; Pancreatic Elastase; Protease Inhibitors; Protein Binding; Swine

In order to determine the anti-atherosclerotic action of elastase, the aortas from four groups of rats--group N fed a normal diet, group D fed an atherogenic diet with vitamin D2, group N + Ela fed a normal diet with elastase, and group D + Ela fed an atherogenic diet and vitamin D2 with elastase--were studied histologically after 3, 6, 9, and 12 weeks of feeding. Group D displayed a remarkable atheromatous change, while the change was insignificant in group D + Ela. The histopathological findings in group D consisted of marked rarefaction, fat deposition, and atheroma in the subendothelial tissue and tunica intima; Van Gieson's staining revealed a conspicuous decrease in elastic fibres, and the remaining elastic fibres had such abnormalities as a tortuous course, bends, and fissures. For group D + Ela, on the other hand, there were few foam cells in the subendothelial tissue and tunica intima and much less marked rarefaction of interstice and fat deposition. Further, the arrangement of elastic fibres was only slightly disordered, and the decreases in elastic fibres and their fissures were moderate. In sharp contrast to group D. which showed marked calcium deposition, group D + Ela was found to have low calcium deposition. No macroscopic and histopathologic abnormalities were found in groups N and N + Ela. Elastase had an inhibitory effect on experimental atherosclerosis in the rat and also regulated the degradation and biosynthesis of elastin, which resulted in the regeneration of elastic fibres.

Topics: Animals; Aorta; Arteriosclerosis; Calcium; Coronary Vessels; Diet, Atherogenic; Elastic Tissue; Elastin; Male; Muridae; Pancreatic Elastase

Human serum was found to contain enzyme activities hydrolyzing succinyl trialanine paranitroanilide and 3H-kappa-elastin Sepharose substrates. Both types of activities could be partly abolished by serine active site titrants (phenylmethanesulfonylfluoride, diisopropylphosphorofluoridate) and partly by neutral chelating agents (EDTA; 1-10-phenanthroline). The combination of phenylmethanesulfonylfluoride and EDTA gave a complete inhibition of human serum elastase-type activities indicating the presence of at least two different types of elastases (serine and metalloproteases) in human serum. In nonsmokers, the average serum elastase-type activity on succinyl trialanine paranitroanilide was found equal to 78.1 ng/ml porcine pancreatic elastase equivalents and on 3H-kappa-elastin sepharose beads equal to 688.8 ng/ml. No statistically significant differences were observed in elastase levels in the sera of individuals presenting clinical symptoms of atherosclerosis. The sera of patients suffering from chronic obstructive lung diseases contained, however, higher amounts of elastase-type activities, respectively equal to 237.2 ng/ml on succinyl trialanine paranitroanilide and 1,096 ng/ml on 3H-kappa-elastin Sepharose beads and was quantitatively significant when compared with control subjects.

Topics: Adult; Aged; Arteriosclerosis; Elastin; Humans; Lung Diseases, Obstructive; Middle Aged; Oligopeptides; Pancreatic Elastase; Sepharose; Substrate Specificity

In a previous paper (1) the organization of an experimental arterial thrombus in rat aorta during the first six days was described. The present paper will set out the thrombus organization during the following weeks and months. Within one month, fibrin and platelets inside the thrombus disappear, and are replaced by smooth muscle cells, collagen and elastin. Elastin was deposited in two forms - granular and strand-like, according to exposure to the pulsatile blood flow. In the course of that period the thrombus surface was covered by endothelial cells. Small, non-endothelialized areas, often with adhering thrombi, were found at all time intervals. The occurrence of thrombi of various ages is suggestive of continuing rethrombosis, presumably due to a permanently disturbed haemodynamical situation.

Topics: Animals; Aorta; Arteriosclerosis; Elastin; Endothelium; Fibrin; Muscle, Smooth, Vascular; Platelet Adhesiveness; Rats; Recurrence; Thrombosis; Time Factors

Topics: Animals; Aorta, Thoracic; Arteriosclerosis; Chlorella; Collagen; Diet, Atherogenic; Elastin; Lipids; Phospholipids; Proline Oxidase; Protein-Lysine 6-Oxidase; Rats; Thyroid Hormones

Elastase-type proteases were shown to be produced by arterial smooth muscle cells and fibroblasts in culture and are probably involved in the development of the arterio-atherosclerotic process (1-4). The present investigation was aimed at the quantitative determination of the elastase-type enzyme activity in the aortas of rabbits submitted to two different athero-arteriosclerosis inducing treatments: high cholesterol diet and immunization with kappa-elastin peptides. Simultaneously we determined the incorporation of 14C-lysine in cross-linked elastin peptides by the surviving aorta extracts, determined with a synthetic substrate (Suc-(Ala)3-pNA) increased two fold after 1.5 month cholesterol diet, and three fold after 8 weeks of immunization with kappa-elastin in complete Freund's adjuvant. The incorporation of 14C-lysine in cross-linked elastin slightly increased (+20%) in cholesterol-fed aorta-explants and strongly decreased (-65%) in the immunized aorta-explants, on a DNA basis. These results confirm our contention that atherogenic stimuli produce an increase of elastase-type enzyme activity in the arterial wall. This increase appears to be correlated with elastic fibers degradation. It may also be accompanied by a decrease of elastin biosynthesis as in the kappa-elastin induced immuno-arteriosclerosis model.

Topics: Animals; Aorta; Arteriosclerosis; Cholesterol, Dietary; Elastin; Immunization; Male; Pancreatic Elastase; Peptide Hydrolases; Peptides; Rabbits

The content of fibrillar proteins was studied in 50 aortas of children dying at the age of 4 to 16 years of various diseases and accidents. In the intact intima of aortas the content of elastin and collagen increased with age. In lipid spots of the vascular wall of children the content of elastin was lower than in the intima, and the amount of collagen was higher than in the normal intima. In 15% of the aortas of children over 10 years of age lipid spots were found the content of collagen in which was above its average levels and biochemically reflected the development of collagen structures in lipid spots with destruction of lipid containing cells and release of lipids into the extracellular space. In rhythmical structures the content of fibrillar proteins increased as compared with normal intima irrespective of the age. The rhythmical structures with lipoidosis were intermediate with regard to the content of fibrillar proteins between "pure" rhythmical structures and lipid spots.

Topics: Adolescent; Aging; Aorta; Arteriosclerosis; Child; Child, Preschool; Collagen; Connective Tissue; Elastin; Humans; Lipidoses; Muscle Proteins

Experimental atherosclerosis in rats was produced by feeding them atherogenic diet for ten months. Elastin and collagen content of the arterial wall as well as some aspects of the metabolism of these proteins were studied. A decrease of elastin content was accompanied by its enhanced susceptibility of enzymatic hydrolysis in vitro. An increase of soluble collagen fractions in tissue and a simultaneously enhanced level of collagen catabolites in serum and urine were found. The present work deals with a disturbed elastin and collagen metabolism in experimental atherosclerosis and shows simultaneous participation of these compounds in pathogenesis of this disease.

Topics: Animals; Arteries; Arteriosclerosis; Collagen; Connective Tissue; Diet, Atherogenic; Elastin; Lipid Metabolism; Male; Rats; Rats, Inbred Strains

Topics: Animals; Antihypertensive Agents; Aorta; Arteriosclerosis; Aspirin; Cholesterol; Cholesterol, Dietary; Cholestyramine Resin; Collagen; Coronary Vessels; Dextrothyroxine; Dipyridamole; Elastin; Lipids; Lipoproteins, LDL; Macaca fascicularis; Pyrimidines

Rabbits were fed an atherogenic or normal control diet for 3 months; half of each group were treated with mestranol--norethynodrel (M--N) and half with cottonseed oil vehicle. At the end of the 3-month period rabbits were killed and aortic collagen and elastin synthesis determine. Collagen and elastin synthesis was increased in aortas of rabbits on an atherogenic diet, but those treated with M--N had a lower rate of collagen synthesis and less deposition of cholesterol in the aorta than those administered cottonseed oil. It is suggested that long-term administration of the contraceptive steroid combination may retard the progression of atherosclerosis through the hormone's effect on vascular connective tissue.

Topics: Animals; Aorta; Arteriosclerosis; Cholesterol; Collagen; Contraceptives, Oral; Contraceptives, Oral, Combined; Elastin; Estrogens; Female; Mestranol; Norethynodrel; Rabbits

Topics: Animals; Aorta; Aortic Diseases; Arteriosclerosis; Carbon Disulfide; Cholesterol, Dietary; Connective Tissue; Diet, Atherogenic; Elastin; Glycosaminoglycans; Rabbits; Time Factors

Topics: Animals; Arteries; Arteriosclerosis; Calcium; Cholesterol; Cholesterol Esters; Collagen; Elastin; Haplorhini; Macaca mulatta; Male; Phospholipids

Internal diameter, thickness of media, and surface density of elastin in media of both pulmonary trunk and aorta were determined in a random group of 100 adults. Because of contrasting results of histologic vs chemical studies of the amount of elastin in the pulmonary trunk, we have used a television image analyzer for objective determination of surface density of elastin in histologic slides, applying the same method to the aorta for comparison. Both caliber and medial thickness of the pulmonary trunk increase somewhat with age. The surface density of elastin in the pulmonary trunk is not influenced by age and averages approximately 26%, with considerable individual variation. In patients with pulmonary hypertension, this percentage is consistently higher. We conclude that the decrease in extensibility of the aging pulmonary trunk is caused by changes in physical properties of the constituents of its wall, rather than by a decreasing elastin content.

Topics: Adolescent; Adult; Aged; Aging; Aorta, Thoracic; Arteriosclerosis; Densitometry; Elastin; Female; Humans; Hypertension, Pulmonary; Male; Middle Aged; Pulmonary Artery; Surface Properties

The role of the immunocompetent system in the development of experimental atherosclerosis was studied in experiments with 51 rabbits given hydrocortisone injections. Hydrocortisone produced atrophy of T and B systems of the lymph nodes and spleen. Under these conditions the experimental sclerosis developed little regardless high lipid blood level. This circumstance provides one more argument of the role played by the immunologic factors in the formation and development of atherosclerosis.

Topics: Animals; Arteriosclerosis; Autoantibodies; B-Lymphocytes; Cell Count; Collagen; Elastin; Hydrocortisone; Immunosuppression Therapy; Lymph Nodes; Plasma Cells; Rabbits; T-Lymphocytes

The effects of feeding an experimental diet consisting of 16.25% (w/w) dry powdered egg yolk and 30.8% total fat (20% from lard) was compared with an isocaloric amount of control (stock) regimen in male Hormel miniature pigs. The experimental diet was started at 30 weeks of age. The serum lipids (cholesterol and triglycerides) were determined at 5- week intervals until 55 weeks of age. At 55 weeks, the pigs were sacrificed and aortae evaluated for fatty streaks and atherosclerotic lesions. The ingestion of egg yolk diet resulted in hypercholesterolemia as the final serum fold over its initial value. Initial and final serum cholesterol levels of the controls were not statistically different. Triglyceride concentrations were nof influenced by an egg yolk regimen. It was observed that thoracic and abdominal atherogenesis was markedly increased in pigs fed the experimental diet as compared to the controls. No lesions were observed in the coronary arteries. There were no significant changes in the percent of collagen, elastin or C/E ratio in the thoracic and abdominal aortae as well as the coronary arteries. These results indicate that feeding miniature pigs an egg yolk : larg diet produced hypercholesterolemia, increased fatty streaking and atherosclerosis in the aortae.

Topics: Animals; Aortic Diseases; Arteriosclerosis; Cholesterol; Collagen; Diet, Atherogenic; Egg Yolk; Elastin; Female; Lipids; Male; Swine; Triglycerides

Collagen and elastin synthesis was determined in 5 regions of the vascular system in rabbits on (a) normal diet and (b) atherogenic diet. Increased connective tissue synthesis was found in 3 different sections of the aorta and in the pulmonary artery of rabbits on the atherogenic diet. The inferior vena cava showed no difference between the two groups. Regional variation in connective tissue synthesis was found in both normal and atherosclerotic animals, the vessels associated with the greatest degree of pulsatile distention in vivo having the greatest synthesis and the inferior vena cava, a low pressure, low distention vessel having the lowest synthesis. It is concluded that the atherogenic process includes stimulation of collagen and elastin synthesis. It is suggested that in addition to the effect of pressure on connective tissue synthesis, pulsatile distention may be a factor in synthesis and may be related to lesion formation.

Topics: Animals; Aorta, Abdominal; Aorta, Thoracic; Arteriosclerosis; Blood Pressure; Blood Vessels; Cholesterol; Collagen; Diet, Atherogenic; Elastin; Hydroxyproline; Male; Pulmonary Artery; Rabbits; Vena Cava, Inferior

Female Wistar rats were exposed to CS2 for 13 months. Afterwards collagen and elastin content in aorta and lungs was determined. In addition, collagen and non-collagen protein biosynthesis was determined using 14-C glycine incorporation to proteins. Collagen and elastin content in aorta wall and elastin concentration in lungs were found to be increased. Isotopic method indicated that the specific activity of collagen in aorta wall was increased and activity of pulmonary collagen and non-collagen proteins of aorta and lungs was decreased. The above is indicative of: lowered biosynthesis of noncollagen proteins of aorta and lungs, increased biosynthesis of aorta collagen and increased biosynthesis of aorta and lung elastin. Increased biosynthesis of collagen and elastin in aorta may suggest a possibility of CS2 atherogenic effects.

Topics: Animals; Aorta; Arteriosclerosis; Carbon Disulfide; Chronic Disease; Collagen; Connective Tissue; Elastin; Female; Lung; Rats; Stimulation, Chemical

Elasticity of carotid arterial segments of rabbits proximal and distal to an induced ligation was examined. In the presence of both ligation and hypercholesterolemia, longitudinal distensibility was decreased while circumferential distensibility increased. The decrease in longitudinal distensibility was attributed to a decrease in the slack of collagen while the increase in circumferential distensibility was attributed to an increase in the slack of collagen as well as a decrease in the elastances of elastin and collagen. Cholesterol alone was found not to affect the elasticity, while ligation acting alone slightly decreased the circumferential distensibility while leaving the longitudinal distensibility unchanged. High serum cholesterol was also found to accelerate intimal proliferation in regions near the ligature. Some intimal proliferation was seen near the ligature, but this could not be quantitated as the sections were too short for pressure fixation. If intimal proliferation is a precursor of atherosclerotic lesions, then formation of these lesions might be accelerated near occluded regions and maybe also in regions of disturbed blood flow when high serum cholesterol is present.

Topics: Animals; Arteriosclerosis; Carotid Arteries; Cholesterol, Dietary; Collagen; Elasticity; Elastin; Male; Rabbits

Topics: Animals; Aorta; Arteriosclerosis; Castration; Collagen; Elastin; Estradiol; Female; Gonadal Steroid Hormones; Mestranol; Progesterone; Rats; Testosterone

The influence of two levels of plasma cholesterol concentration on the long-term regression of atherosclerotic plaques in rhesus monkeys (Macaca mulatta) was studied. Forty-eight young adult male rhesus monkeys were fed an atherogenic diet for 19 months, then diets designed to maintain plasma cholesterol concentrations at 280-320 mg/dl (actual 316 +/- 10 mg/dl; mean +/- SEM) of 180-220 mg/dl (actual 204 +/- 4 mg/dl). Twelve animals were killed after 19 months to evaluate the atherosclerosis produced. The remaining 36 monkeys were studied after 48 months of atherosclerosis regression. Significantly greater amounts of accumulated nonesterififed and esterified cholesterol were lost from the arteries of monkeys that underwent regression at about 200 mg/dl, in comparison with 300 mg/dl. Regression at both plasma cholesterol concentrations resulted in increased collagen and decreased elastin content in the thoracic aorta but not in the other arteries studied. After regression at 300 mg/dl there was no change (83%) in the frequency of calcification of the thoracic aorta, while at 200 mg/dl the frequency of calcification was reduced to 50%. When compared with monkeys whose athersclerotic lesions were produced in an identical manner but were regressed for only 24 months, after 48 months had increased cholesterol concenrations in the thoracic aorta and carotid artery but not the abdominal aorta of iliaco-femoral artery, regardless of the plasma cholesterol concentration. The lipid composition of the regressed plaque suggested a change in plaque lipid toward the character of extracellular deposits described physically as crystalline in nature. The physical state was influenced by the length of the regression period and the plasma cholesterol concentration during regeression. In the thoracic aorta, principally as a result of changes in elastin content, the collagen-to-elastin ratio increased between 24 and 48 months of regression. It is proposed that the differences in removal of cholesterol from the thoracic and abdominal aorta after 24 and 48 months of regression in animals at 300 mg/dl may be influenced by the rearrangement of connective tissue. On the basis of the lipid and mineral content of uncomplicated atherosclerotic plaques after 4 yers of regression, it appears that the plasma cholesterol concentration during the regression period is a signigicant factor influencing the extent of plaque regression as well as the potential for further progression.

Topics: Animals; Arteries; Arteriosclerosis; Calcium; Cholesterol; Cholesterol, Dietary; Collagen; Elastin; Macaca mulatta; Organ Size; Phospholipids

Destruction of elastic and collagenous fibers in lipid spots and atherosclerotic plaques in rabbit experimental atherosclerosis is associated with exposure of previously latent antigenous determinants of structural arterial proteins and appearance of circulating antibodies to collagen, elastin and structural glycoproteins. By the 4th month of the experiment there is an abrupt decrease in the titres of the above antibodies fixed to degeneratively altered fibrous structures of the aortal wall. Sedimentation of circulatory antivascular antibodies is associated with the enhanced destruction of collagenous and elastic fibers, with proliferation of the connective tissue and dramatic progress of the atherosclerotic process.

Topics: Animals; Aorta; Arteriosclerosis; Collagen; Diet, Atherogenic; Elastin; Glycoproteins; Proteins; Rabbits; Time Factors

Alteration of the fatty acid composition of atherogenic test diets has been a widely recognized method for influencing the character and severity of atherosclerotic lesions. The addition of peanut oil or coconut oil to cholesterol-supplemented diets has been shown to produce lesions of a fibrous nature in several species. In the present study, addition of 8% peanut oil to a 2% cholesterol diet accelerated the formation of atherosclerotic lesions which were more fibrous after only 90 days than those previously seen in rabbits even after 6 months on a diet supplemented with cholesterol alone. Collagen, elastin and non-fibrous protein synthesis were all increased over control values, as previously seen in aortas from rabbits given cholesterol supplementation alone. However, the addition of peanut oil to the 2% cholesterol diet produced a preferential increase in the rate of aortic collagen synthesis per unit dry, defatted weight compared with the increases seen in elastin, non-fibrous protein or total protein synthesis. Collagen deposition in proliferative intimal plaques was evident by histological examination. These focal accumulations, however, did not result in significant increases in either total collagen content of the whole descending thoracic aorta or in collagen concentration expressed per unit of dry, defatted weight. These data suggest that, while a portion of the increased synthetic rates may be a direct result of aortic hyperplasia, the proportionally greater increase in collagen synthesis in these lesions is attributable to the addition of peanut oil to the atherogenic diet. Although the lesions produced in this experiment lacked the overt fibrosis seen in man and in some forms of experimentally induced atherosclerosis, the relative synthetic rates of collagen, elastin and nonfibrous protein described here suggest that even a small preferential increase in collagen synthesis compared with non-collagen protein synthesis may gradually lead to a more fibrous lesion.

Topics: Animals; Aorta, Thoracic; Aortic Diseases; Arachis; Arteriosclerosis; Cholesterol, Dietary; Collagen; Diet, Atherogenic; Elastin; Male; Oils; Protein Biosynthesis; Rabbits

Topics: Aorta; Arteriosclerosis; Autoantibodies; Collagen; Complement Fixation Tests; Elastin; Humans

Topics: Animals; Aorta; Arteriosclerosis; Collagen; Diet, Atherogenic; Elastin; Glucocorticoids; Glycosaminoglycans; Hydrocortisone; Rabbits

Topics: Animals; Arteriosclerosis; Cholesterol, Dietary; Collagen; Coronary Vessels; Diet, Atherogenic; Elastin; Haplorhini; Humans; Macaca fascicularis; Macaca mulatta; Male; Physical Exertion; Rabbits

Topics: Animals; Aorta; Arteries; Arteriosclerosis; Aspirin; Calcium; Cholesterol; Cholesterol, Dietary; Collagen; Coronary Disease; Coronary Vessels; Diet, Atherogenic; Dipyridamole; Elastin; Haplorhini; Lipoproteins, LDL; Macaca fascicularis

Topics: Animals; Aorta; Aortic Diseases; Arteriosclerosis; Collagen; Diet, Atherogenic; Elastin; Hyperthyroidism; Rabbits

Activated smooth muscle cells exhibit a statistically significant (p less than 0.025) higher prostacyclin production than the contractiles. It is concluded, that the proliferation of the metabolically activated cells, which is an early event in atherogenesis, could be due to prostacyclin regulation.

Topics: Adult; Arteriosclerosis; Cell Division; Collagen; Elastin; Epoprostenol; Humans; Male; Middle Aged; Muscle, Smooth, Vascular; Prostaglandins; Splenic Artery

The authors examined neosynthesis of fiber proteins (scleroproteins) in the aorta of rats with genetic hypertonia and with experimental atherosclerosis after application of 3H-proline and 3H-lysine and subsequent determination of radioactivity of collagenous and elastic in the aortic wall. There was a great increase in incorporation a labelled precursors of collagen and elastin in the aorta of hypertonic and atherosclerotic animals in comparison with the control rats-a manifestation of increased "de novo" synthesis of fiber proteins in rats with these arterial diseases. Furthermore the increased collagenosis dominated over that of elastogenesis. The irregularity in the activation of biosynthesis of both sclero-proteins in rats with hypertonia and atherosclerosis caused remodeling of macromolecular structure of the aretrial wall with a predominance of collagen over the remaining components of the connective tissue matrix. The resulting fibrosis of the arterial wall favoured the fixation of hypertonia and progression of atherosclerosis.

Topics: Animals; Aorta; Arteriosclerosis; Collagen; Elastin; Hypertension; Hypertension, Renal; Lysine; Proline; Protein Biosynthesis; Rats; Rats, Inbred Strains

Elastin was extracted from human aortic plaque and adjacent grossly normal intima by the following methods: (1) 0.1 N NaOH at 100 degrees C, (2) hot NaOH and 0.2 M EDTA, (3) 5 M guanidine--HCl and collagenase, (4) guanidine--collagenase and dithioerythritol--urea--sodium dodecyl sulfate, (5) guanidine--collagenase and EDTA, (6) 10% NaCl and collagenase, and (7) NaCl--collagenase and EDTA. All elastin samples contained small amounts of carbohydrate and hydroxyproline. The lipid content of non-plaque intimal elastin samples was small (2--3%), whereas it increased to 4--6% in plaque intima. The lipid composition of elastin preparations varied significantly with the extraction procedure. Elastin from plaque intima contained significantly more cholesterol (50--60%) and less triglyceride and phospholipid than elastin of non-plaque intima (30--50% cholesterol). The contents of free and esterified cholesterol were comparable in all preparations. The main phospholipid in all samples was sphingomyelin, which comprised between 50 and 80% of the total phospholipid. Compared with NaOH-purified elastin, the other elastin samples were characterized by an increased phosphatidyl--choline content, while they all contained an almost equal amount of phosphatidylethanolamine. In elastin samples from plaque intima, the polar amino acids were increased, whereas cross-linking amino acids were decreased. The polarity and hydroxyproline content of elastin samples were slightly decreased after treatment with EDTA or dithioerythritol--urea--sodium dodecyl sulfate.

Topics: Amino Acids; Aorta; Arteriosclerosis; Carbohydrate Metabolism; Cholesterol; Cholesterol Esters; Elastin; Humans; Lipid Metabolism; Phospholipids; Triglycerides

If at all successful, tis paper will emphasized the perspective that the current understanding of the interactions between arterial walls and the flowing blood, the major events leading to the development of arterial diseases, still has many obvious gaps. Even as superficial and selective a discussion as this one points out the truism that any hypothesis for the pathogenesis of atherosclerosis which considers only one of the structural elements in the artery wall is almost certainly incomplete. Decades ago, one of the great conceptual insights developed in the pioneering studies of intermediary metabolism was that well-integrated biochemical pathways have multiple interrelated controls. The many extracellular molecules present in aorta with both structural biochemistry and functions as yet only partially understood may well be components of analogous control systems.

Topics: Arteries; Arteriosclerosis; Carbohydrate Conformation; Cell Division; Elastin; Extracellular Space; Glycosaminoglycans; Growth Substances; Humans; Proteoglycans

Mitral valve, coronary arteries, cartilage, and liver were studied by light and electron microscopy in a 15 year old boy with Morquio's syndrome, a genetic mucopolysaccharidosis, in which a deficiency of lysosomal hexosamine sulfatase is associated with accumulations of keratan sulfate in various organs. Coronary artery intimal sclerosis was a prominent feature of this disorder. Ultrastructural examination revealed numerous intimal smooth muscle cells containing storage vacuoles consistent with lysosomes. This was associated with marked interstitial deposition of collagen, elastin, and basement membrane material. Recent studies of human and experimental atherosclerosis have demonstrated the accumulation of cholesterol within vascular smooth muscle cell lysosomes. Intralysosomal accumulation of substrates other than cholesterol is also associated with vascular intimal sclerosis in genetic lysosomal disorders such as Fabry's disease and Hurler's syndrome. Lysosomal storage of undegraded substrate may be an important pathogenetic mechanism in the development of sclerotic vascular lesions.

Topics: Adolescent; Arteriosclerosis; Basement Membrane; Collagen; Coronary Disease; Coronary Vessels; Elastin; Humans; Liver; Male; Microscopy, Electron; Mucopolysaccharidosis IV; Muscle, Smooth; Vacuoles

Topics: Animals; Aorta; Arteriosclerosis; Calcinosis; Cholesterol; Demecolcine; Diet, Atherogenic; Elastin; Etidronic Acid; Mitosis; Organ Size; Rabbits

Topics: Animals; Aorta; Arteries; Arteriosclerosis; Carotid Arteries; Cholesterol; Cholesterol Esters; Collagen; Diet, Atherogenic; Elastin; Femoral Artery; Haplorhini; Macaca fascicularis; Male; Minerals; Phospholipids; Triglycerides

Detailed studies of aortas from 8 rabbits showed that serious artefacts occur if the aortas are pinned at their in vivo dimensions, rather than fixed at physiological pressure. In the pinned aortas, the proximal parts of the branches were pulled up onto the aortic wall. This was more pronounced for the large branches of the abdominal aorta than for the smaller intercostal branches. This artefact caused atherosclerotic lesions, which had developed at the origin of the branch, to appear as if they were entirely on the aortic wall. We found that a marked change in the elastin pattern was present at the origin of the branch; this can be used to mark the true origin of the branch. With the pressure technique we found that lesions had different shapes and locations at different branch points.

Topics: Animals; Aorta; Arteriosclerosis; Elastin; Rabbits; Renal Artery

Topics: Animals; Aorta; Arteriosclerosis; Cattle; Chickens; Collagen; Dogs; Elastin; Glycoproteins; Glycosaminoglycans; Goats; Rabbits; Rats; Swine

Topics: Adolescent; Adult; Aged; Aging; Aorta; Arteriosclerosis; Breast; Breast Neoplasms; Child; Desmosine; Elastin; Female; Humans; Middle Aged; Pancreatic Elastase

Lysyl oxidase is the copper-dependent enzyme responsible for the normal cross-linking of both collagen and elastin which is necessary for their functional integrity. There is now strong evidence that this enzyme is vitamin-B6-dependent. The earliest visible lesion of atherosclerosis, commonly found in human neonatal coronary arteries and probably indicative of the location of future atherosclerotic plaques, is a focal splitting of the internal elastic lamina, the cause of which has hitherto remained unexplained. It is suggested that this lesion is the result of imperfect cross-linking of arterial elastin as well as collagen, and is caused by a maternal deficiency of vitamin B6 which is commonly found in pregnancy and which could thus impair the function of lysyl oxidase. Prophylactic supplementation of maternal diet with adequate vitamin B6 is therefore suggested.

Topics: Arteriosclerosis; Blood Vessels; Collagen; Elastin; Female; Humans; Infant, Newborn; Pregnancy; Pregnancy Complications; Protein-Lysine 6-Oxidase; Pyridoxine; Vitamin B 6 Deficiency

Two neutral proteases have been isolated from aortas and human breast tumors. The aortic elastase-like enzyme has been further purified. The details of this purification procedure will be given and some of the properties of the purified enzyme (susceptibility to various kinds of substrates, degree of inhibition of serum inhibitors, alpha 1-antitrypsin and alpha 2-macroglobulin). This elastinolytic activity of the aorta increased with age and with the degree of atherosclerosis. Both parameters seem to act independently and in a cumulative fashion. Elastinolytic activity has been demonstrated in extracts of human breast carcinomas and is exponentially related to the age of the patient. There exists a parallel neosynthesis of elastin which increased also with the age of the patient. Some characteristics of the polymeric elastin isolated from the tumor tissue will be given. The possible role of this neutral protease present in human aortas and human breast carcinomas will be discussed.

Topics: Aging; alpha 1-Antitrypsin; alpha-Macroglobulins; Animals; Aorta; Arteriosclerosis; Breast Neoplasms; Elastin; Female; Humans; Kinetics; Pancreatic Elastase; Swine

Elastin preparations were isolated from human thoracic aorta, from atherosclerotic and from grossly normal regions. A relatively mild procedure was used to avoid hot alkaline extraction and autoclaving. The elastase digest of the aortic elastin was chromatographed on a Sephadex G-100 column and separated into two fractions: A (larger molecular weight) and B (smaller molecular weight). The ratio of fraction A to total aortic elastin increased with age and the development of the atherosclerosis. Amino acid and sugar analyses showed that fraction A consistently contained more polar amino acids, hexose, hexosamine and L-fucose, and less sialic acid, in comparison with fraction B. Part of the elastin preparation was incubated with human low-density lipoprotein; a considerable amount of lipid, especially cholesterol, was transferred from the lipoprotein to the elastin. Estimation of protein and cholesterol in fractions A and B of the elastase hydrolyzate of incubated elastin showed that most of the cholesterol taken up by elastin had been in fraction A. The increased proportion of fraction A in aortic elastin derived from plaque areas appeared responsible for the marked lipid-binding capacity of plaque elastin.

Topics: Age Factors; Aged; Amino Acids; Aorta, Thoracic; Arteriosclerosis; Binding Sites; Cholesterol; Elastin; Female; Humans; Lipoproteins, LDL; Male; Middle Aged; Peptide Fragments; Phospholipids; Triglycerides

Topics: Apolipoproteins; Arteriosclerosis; Calcium; Cholesterol; Collagen; Elastin; Glycosaminoglycans; Humans; Lipoproteins; Lipoproteins, HDL; Lipoproteins, LDL; Lipoproteins, VLDL

Topics: Animals; Arteriosclerosis; Calcium; Cholesterol; Collagen; Diet, Atherogenic; Elastic Tissue; Elastin; Haplorhini; Protein Binding; Rabbits

Topics: Animals; Aorta; Arteriosclerosis; Calcitonin; Calcium; Elastin; Female; Freund's Adjuvant; Male; Rabbits

Topics: Animals; Aorta; Arteriosclerosis; Diet, Atherogenic; Elastin; Hypertension; Lysine; Rats; Rats, Inbred Strains; Time Factors

A method is presented for grinding and extracting very small samples of tough fibrous tissue from single atherosclerotic lesions of human aortas. Grinding to a powder was easily accomplished while the samples were frozen in liquid nitrogen in a porcelain micromortar. Extractions of the powder were made first in the mortar and then in tapered centrifuge tubes. Salt soluble, dodecyl sulfate--mercaptoethanol--urea soluble and hot alkali soluble fractions were obtained, in addition to a hot alkali insoluble elastin residue from each sample. Variation in the protein composition of 23 samples from the lumenal surface of the severely atherosclerotic aorta of a 58-year-old human male were determined. The proteins soluble in the buffered-saline and the dodecyl sulfate-urea soluble polypeptides from each sample were analyzed by dodecyl sulfate--acrylamide gel electrophoresis. The amino acid compositions of the insoluble elastin fractions were determined. The 5 grossly normal intima samples had very similar gel electrophoresis band patterns and amino acid compositions. The 3 samples of necrotic gruel had markedly different dodecyl sulfate--urea soluble polypeptides than either normal or calcified tissue; they also had elastin fractions whose amino acid compositions were unique in that they contained 10 times more serine than elastin fractions from grossly normal intima. The 3 calcified samples had less saline or dodecyl sulfate soluble protein than either grossly normal or necrotic gruel samples, and had very altered elastin fraction compositions characterized by much higher contents of hydroxylysine than grossly normal intima. The elastin fractions of necrotic gruel and calcified tissue samples had little or no isodesmosine or desmosine, suggesting that little of the elastin found in healthy aorta tissue was present.

Topics: Amino Acids; Aorta; Aortic Diseases; Arteriosclerosis; Elastin; Humans; Hydroxylysine; Male; Middle Aged; Peptides; Proteins

Topics: Adult; Animals; Aorta; Arteriosclerosis; Breast Neoplasms; Elastic Tissue; Elastin; Humans; Middle Aged; Rabbits

Topics: Adult; Aging; Animals; Aorta; Arteries; Arteriosclerosis; Child; Collagen; Elastin; Elephants; Female; Femoral Artery; Glycosaminoglycans; Humans; Iliac Artery; Lung; Male; Middle Aged; Uronic Acids

Collagen, elastin and non-fibrous protein synthesis were measured in the aortas of male New Zealand white rabbits fed a diet containing 2% cholesterol for 140 or 180 days. At these time periods increases in aortic cholesterol and cholesteryl esters were evident. The atherosclerotic lesions induced were predominantly of the foam cell type although some areas of early fibrous lesion formation were noted. These changes in lipid concentration and arterial morphology were accompanied by a significant increase in collagen synthesis as determined by the formation of [14C]hydroxyproline. This increase, however, was not confined specifically to collagen since both elastin and non-collagenous proteins were also being synthesized at a higher rate. The two-fold increase in the rates of both fibrous and non-fibrous protein synthesis may in part be a consequence of marked intimal hyperplasia necessitating a general increase in protein synthesis.

Topics: Animals; Aorta; Arteries; Arteriosclerosis; Cholesterol; Cholesterol Esters; Collagen; Diet, Atherogenic; Elastin; Male; Muscle, Smooth; Protein Biosynthesis; Rabbits; Time Factors

Topics: Animals; Arteriosclerosis; Collagen; Elastic Tissue; Elastin; Morphogenesis; Muscle, Smooth; Rabbits

Topics: Animals; Arteries; Arteriosclerosis; Collagen; Connective Tissue; Elastic Tissue; Elastin; Humans

Macroscopically lesion-free parts of human aortas with no or light lesions (group I) and advanced atherosclerotic lesions (group II) were submitted to a series of successive extractions in order to "solubilize" all the macromolecular components of the arterial wall ("chemical dissection"). Lipids were extracted with methanol-chloroform from all these macromolecular fractions and analyzed for cholesterol, triglycerides, phospholipids. The fatty acid composition of the separated fractions was determined by GLC. The lipid composition and fatty acid spectrum of the macromolecular fractions of group I and group II aortas was compared. Total lipids increased in the freely extractable ("non associated lipids, approximately 78% of total) fraction as well as in the fraction "associated" with collagen and elastin. Free and esterified cholesterol increased also both in the "freely extractable" and in the collagen-elastin-associated lipids", approximately 78% of total) fraction as well was higher (+ 100%) than that of free cholesterol (+ 60%). Triglycerides increase also by 15 to 70% in all fractions except in the elastin-associated fraction. Free fatty acids increased by 40 to 400% in all extracts associated with macromolecular fractions but not in the "freely extractable" fraction where they decreased. Phospholipids show less marked variations (approximately less than 10%) and decrease in the elastin associated lipids of group II aortas. The fatty acid spectrum of group II lipids associated with macromolecules differs from that of group I. There is a relative increase of longer chains (C greater than 18, especially 20:1 and 20:2 acids). No such increase in the "long" fatty acids was seen in the "freely extractable" lipid fraction. Elastin isolated from group II aortas is significantly enriched in total lipids, cholesterol (free and esterified) and free fatty acids and contains the widest spectrum of fatty acids (from 11:2 to 22:1) with a significant fraction of total fatty acids as "odd" carbon chains. There appears to be a correlation between the decrease of triglyceride-bound fatty acids and the increase of free fatty acids. The free fatty acid concentration exceeds both in group I and II aortas the concentration of fatty acid esters. This increase in free fatty acids "associated" with intercellular matrix macromolecules and especially with elastin may be the result of an increased hydrolysis of esters and/or a decreased esterification in advanced atherosclerotic

Topics: Aorta; Arteriosclerosis; Cholesterol; Collagen; Elastin; Fatty Acids; Fatty Acids, Nonesterified; Humans; Lipids; Phospholipids; Triglycerides

Topics: Amino Acid Sequence; Arteriosclerosis; Collagen Diseases; Connective Tissue; Connective Tissue Cells; Elastin; Glycoproteins; Humans

Topics: Animals; Arteriosclerosis; Collagen Diseases; Cutis Laxa; Elastin; Humans; Lathyrism; Models, Chemical; Rabbits; Rats; Structure-Activity Relationship

Topics: Aorta; Arteriosclerosis; Collagen; Diabetes Complications; Diabetes Mellitus; Diabetic Angiopathies; Elastin; Humans

An isotopic assay of elastolytic activity is performed; the iodine-125 ions retained inside the elastin framework were removed by appropriate treatment. This acute substrate enables us to study the role of trypsin on elastase activity and facilitates the study of elastase role in atherosclerosis.

Topics: Animals; Arteries; Arteriosclerosis; Dogs; Elastin; Hydrogen-Ion Concentration; In Vitro Techniques; Iodine Radioisotopes; Methods; Pancreas; Pancreatic Elastase; Rabbits; Rats; Swine; Trypsin

The aortic connective tissue components, collagen, elastin, and glycosaminoglycans were isolated and quantitated from monkeys with experimentally-induced fatty streaks, from monkeys on a diet allowing regression of these lesions, and from controls. Although no variations were noted for total, soluble, and autoclavable collagen based on concentration, nonautoclavable collagen was significantly less (p less than 0.02) and elastin was reduced (p less than 0.001) in tissues with fatty streaks. There were no significant differences in total glycosaminoglycan content among the groups, but a large increase of hyaluronic acid (50 to 220 per cent) and a decrease of chondroitin sulfate C (40 to 66 per cent) occurred after regression. Dynamic alterations of arterial connective tissue shown to occur with induction as well as with regression of fatty streaks indicate the importance of connective tissue in maintaining integrity of vascular structures.

Topics: Animals; Aorta; Arteriosclerosis; Cholesterol, Dietary; Chondroitin; Collagen; Connective Tissue; Diet, Atherogenic; Dietary Fats; Elastin; Electrophoresis, Cellulose Acetate; Glycosaminoglycans; Haplorhini; Hyaluronic Acid; Macaca mulatta

Fibrous proteins were measured in five arterial beds in adult cynomolgus monkeys after administration of atherogenic and regression regimens. Atherosclerosis was induced by feeding the monkeys a hypercholesterolemic diet containing 1.2% cholesterol for 17 months. A low-fat, cholesterol-free regression diet was then given for 60 days, 200 days, and 20 months. In atherosclerosis, collagen concentration (mg/g dry weight) and collagen content (mg/cm length of artery) both increased. At 200 days of regression the collagen concentration, but not the collagen content, was higher than it was in atherosclerosis. In late regression (20 months), the collagen content was lower than it was in atherosclerosis, although in the five arterial beds considered together the collagen concentration was not significantly lower. Both the elastin concentration and the elastin content rose in atherosclerosis and decreased in regression. These mass data suggest that fibrous proteins are lost from the arterial wall during a regression regimen. Correlative evidence suggests that younger intimal fibers may be chiefly susceptible to fibrolytic activity, leaving dense intimal scars characteristic of regressed arteries.

Topics: Animals; Aorta; Arteries; Arteriosclerosis; Carotid Arteries; Cholesterol, Dietary; Collagen; Coronary Vessels; Diet, Atherogenic; Elastin; Femoral Artery; Macaca fascicularis; Male; Subclavian Artery

Smooth muscle cells derived from rat aortic media were explanted and grown in culture for 14 to 60 days. During that time they formed a confluent multilayer and depostied extracellular material resembling newly formed elastin. The lipid composition of the cells in culture differed slightly from the parent cells in the intact aorta with respect to a higher phospholipid/DNA ratio and a higher lecithin content. The cholesterol content resembled that of parent cells. After incubation with labeled precursor the cultured cells show an active lipid synthesis; choline is incorporated mainly into lecithin, whereas glycerol and palmitate appear in phospholipids and to a lesser extent in neutral lipids. After a 2 hour pulse and up to 96 hour chase there is a linear fall in the specific acitivty of lecithin with a half-time of 28 to 30 hours. The rate of fall in specific activity of glycerol- or choline-labeled lecithin was found to be similar, indicating that choline does not turn over by an exchange reaction and is a suitable marker for studying phospholipid turnover in cultured cells. The results provide a basis for investigation of the effect of increasing cellular cholesterol content on phospholipid turnover.

Topics: Animals; Aorta; Arteriosclerosis; Carbon Radioisotopes; Cells, Cultured; Cholesterol; Choline; Elastin; Glycerol; Lipids; Male; Microscopy, Electron; Muscle, Smooth; Palmitic Acids; Phosphatidylcholines; Phospholipids; Rats; Sphingomyelins

Elasticity and elastin of arteries in 106 dead people aged 14--74 years were investigated using physico-chemical methods. Depending on the character of morphological manifestations, aortas and arteries were divided into following groups: 1) without morphological manifestations of atherosclerosis; 2) affected by atherosclerosis; 3) vessels of patients who had suffered from atherosclerosis and hypertensive disease; 4) aortas and arteries of patients with atherosclerosis in combination with other somatic diseases. In atherosclerosis and hypertensive disease there were observed specific shifts in the character and intensity of fluorescence of elastin and elasticity as a whole. The intensity of primary fluorescence as an atherosclerotic process progressed and in concomitant hypertensive disease gradually changed. In atherosclerosis there were noted changes in transversal bands in elastin. The growth of transversal bands and intensity of fluorescence were found to be interrelated. Optical density of dissolved elastin with wave lengths (lambda) 240, 260, 280, 300, 320, 360, 400, 490 nm and pH 7.7 and 8.6 was studied. The peak of intensity of absorption of the solution of elastin in all groups referred to above was noted at the wave length lambda=240 nm. Amino-acid composition of dissolved elastin was also studied. It was established that as the process of atherosclerosis progressed, the content of lysine in the wall increased depending on the phase of the process -- lipoidosis, atheromatosis, etc. In the vascular wall there were observed changes in monoamino-oxidase, the latter being of particular importance for maintaining the level of cuprum in tissues.

Topics: Adolescent; Adult; Age Factors; Aged; Aorta; Arteries; Arteriosclerosis; Chemical Phenomena; Chemistry, Physical; Elasticity; Elastin; Humans; Hypertension; Middle Aged; Spectrometry, Fluorescence

Japanese quail were investigated for their utility as a model for the discovery and evaluation of anti-atherosclerosis compounds. Although they possessed suitable characteristics for a screening animal, their development of atherosclerosis was too variable to make them a practical model. A search was conducted to find a means to make quail uniformly atherosclerotic. To this end a line of quail susceptible to experimental atherosclerosis (SEA) were selectively bred. Thus, the SEA Japanese quail is a new animal model for atherosclerosis research.

Topics: Animals; Arteriosclerosis; Cholesterol, Dietary; Cholic Acids; Coturnix; Disease Models, Animal; Elastin; Female; Humans; Male; Quail; Sex Factors; Species Specificity

The purpose of our experiments was to clarify the relationship between the susceptibility to atherosclerosis and chemical composition in the human cerebral, coronary arteries and aorta, and the concentration and composition of human arterial intimal elastic tissues were measured. In the cerebral arteries, the concentration of hot alkali-insoluble elastin was higher than that of the coronary arteries and aortas, and gradually decreased with age. Age-related changes of the elastin in the coronary arteries were quite small. The total polar amino acids and crude ash contents of arterial elastins were affected by age and treatment of elastic tissue wheteher or not EDTA-decalcification was applied prior to alkali-extraction. No significant differences in the amino acid composition of elastin was founded between the cerebral, coronary and aortic intimas and no significant changes to elastin, and or collagen, which can explain the slow development of atherosclerosis in the cerebral artery, were founded. Therefore, from these results, the slower development rate of cerebral atherosclerosis, as compared with other arteries, can not be sufficiently concluded.

Topics: Adolescent; Adult; Amino Acids; Aorta; Arteriosclerosis; Cerebral Arteries; Child; Child, Preschool; Collagen; Coronary Vessels; Elastin; Humans; Infant; Infant, Newborn; Intracranial Arteriosclerosis; Middle Aged

Proteoglycanes, glycoprotein, fibrous collagen and elastin proteins were isolated from normal human aortic intima and from sclerotic lipid and calcium plaques and examined by electron microscope and thermal analysis. Differences between the structure and compositon of normal human aortic wall and aortic lipid plaques are chiefly found in the proteoglycan containing fraction. The calcium plaque shows structural changes in the fibrillar protein components.

Topics: Aorta; Aortic Diseases; Arteriosclerosis; Collagen; Elastin; Glycoproteins; Humans; Proteoglycans

Fractionation of intact and arteriosclerotic aortic and venous intimas was performed. The distribution of the obtained fractions (CTC, CSC, collagen, SGP and elastin), their disc-electrophoretic and immunological behaviour was studied. With the process of arteriosclerosis a decrease of the structural proteins (collagen, SGP, elastin) and an increase in the amount of some proteins of plasmatic origin could be demonstrated. By the use of absorbed immune sera in the immunoelectrophoretic patterns of aortic and venous CTC-extracts two vessel wall specific arcs were found.

Topics: Antigens; Aorta; Arteriosclerosis; Collagen; Elastin; Humans; Veins; Vena Cava, Superior

Topics: Animals; Aorta; Arteriosclerosis; Autoradiography; Basement Membrane; Collagen; Culture Techniques; Elastic Tissue; Elastin; Endoplasmic Reticulum; Extracellular Space; Glycosaminoglycans; Hydroxyproline; Microscopy, Electron; Muscle, Smooth; Proline; Swine; Thymidine; Time Factors; Tritium

Topics: Aorta; Arteriosclerosis; Barbiturates; Calcium; Chemical Fractionation; Chloroform; Edetic Acid; Elastin; Fluorescence; Fluorometry; Humans; Lipids; Methanol; Pancreatic Elastase; Peptides; Pigments, Biological; Solubility; Spectrophotometry

Topics: Amino Acids; Animals; Arteries; Arteriosclerosis; Basement Membrane; Blood Platelets; Collagen; Connective Tissue; Elastin; Extracellular Space; Humans; Hydroxyproline; Iliac Artery; In Vitro Techniques; Microbial Collagenase; Microscopy, Electron; Platelet Adhesiveness; Rabbits; Thrombosis; Trypsin; Umbilical Veins

Topics: Animals; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Collagen; Coronary Disease; Coronary Vessels; Diet, Atherogenic; Disease Models, Animal; Eggs; Elastin; Endothelium; Female; Femoral Artery; Hypercholesterolemia; Iliac Artery; Inclusion Bodies; Male; Marsupialia; Meat; Microscopy, Electron

Topics: Aorta; Arteriosclerosis; Cholesterol; Elastic Tissue; Elastin; Humans

Topics: Arteriosclerosis; Binding Sites; Calcinosis; Calciphylaxis; Calcium; Circular Dichroism; Elastic Tissue; Elastin; Humans; Isoelectric Focusing; Microscopy, Electron; Models, Structural; Molecular Conformation; Molecular Weight; Peptide Chain Initiation, Translational; Peptide Initiation Factors; Spectrophotometry, Infrared; Templates, Genetic

Topics: Arteries; Arteriosclerosis; Binding Sites; Calcinosis; Calcium; Circular Dichroism; Elastin; Humans; Lipid Metabolism; Microscopy, Electron

Topics: Alanine; Arteries; Arteriosclerosis; Calcium; Chemical Phenomena; Chemistry; Elastin; Glycine; Lipid Metabolism; Magnetic Resonance Spectroscopy; Microscopy, Electron; Peptides; Potassium; Proline; Temperature; Valine; Valinomycin; X-Ray Diffraction

Topics: Aging; Animals; Antigen-Antibody Reactions; Antigens; Aorta; Aortic Diseases; Arteriosclerosis; Cattle; Chickens; Complement Fixation Tests; Connective Tissue; Connective Tissue Cells; Cross Reactions; Dogs; Elastic Tissue; Elastin; Geese; Glycoproteins; Graft Rejection; Hemagglutination Tests; Horses; Humans; Hypersensitivity, Delayed; Hypertension; Immune Sera; Ischemia; Muscle, Smooth; Rabbits; Rats; Swine; Transplantation, Homologous

Topics: Adult; Aged; Aging; Amino Acids; Animals; Aorta; Apatites; Arteriosclerosis; Calcinosis; Calcium; Calcium Radioisotopes; Carbonates; Copper; Elastic Tissue; Elastin; Humans; Male; Microscopy, Electron; Middle Aged; Phosphates; Rabbits; Tritium; X-Ray Diffraction

Topics: Adolescent; Adult; Age Factors; Aged; Aging; Animals; Aorta; Arteries; Arteriosclerosis; Blood Platelets; Cattle; Child; Collagen; Connective Tissue; Culture Techniques; Elastic Tissue; Elastin; Female; Fluorescence; Humans; Leukocytes; Male; Middle Aged; Pancreatic Elastase; Phenylalanine; Pregnancy; Proteins; Solubility; Tyrosine; Ultraviolet Rays; X-Ray Diffraction

Topics: Amino Acids; Animals; Antigens; Aorta; Aorta, Abdominal; Aorta, Thoracic; Arteriosclerosis; Cattle; Collagen; Elastic Tissue; Elastin; Elephants; Glycoproteins; Hemagglutination Tests; Hexoses; Hydroxyproline; Immune Sera; Immunodiffusion; Rabbits; Staining and Labeling; Swine

Topics: Animals; Aorta; Aorta, Abdominal; Aorta, Thoracic; Arteriosclerosis; Cattle; Elastic Tissue; Elastin; Elephants; Hydrolysis; Microscopy, Electron; Spectrophotometry, Ultraviolet; Staining and Labeling; Swine

Topics: Animals; Arteriosclerosis; Basement Membrane; Blood Platelets; Carotid Arteries; Cell Membrane; Cholesterol; Cytoplasm; Elastin; Endoplasmic Reticulum; Endothelium; Femoral Artery; Haplorhini; Hardness; Lipids; Macaca; Male; Microscopy, Electron; Mitochondria; Muscle, Smooth; Pinocytosis; Ribosomes; Staining and Labeling; Sutures; Thrombosis; Time Factors

Topics: Age Factors; Aging; Animals; Aorta; Aorta, Thoracic; Arteriosclerosis; Collagen; Elastin; Glycosaminoglycans; Protein Binding; Rats; Sulfates; Sulfur Radioisotopes

Arterial elastin appears to be a proteinlipid complex with the lipid component being bound to elastin peptide groups. In atherosclerotic lesions the lipid content of elastin increases progressively with increasing severity of atherosclerosis. The increases in the lipid content of plaque elastin are mainly due to large increases in cholesterol with about 80% of the cholesterol being cholesterol ester. This deposition of cholesterol in elastin accounts for a substantial part of the total cholesterol accumulation in atherosclerotic lesions of all stages. The present in vitro study suggests that the mechanism involved in the deposition of lipids in arterial elastin may be an interaction of the elastin protein with serum or arterial low density or very low density lipoproteins (LDL and VLDL) resulting in a transfer of lipids, but not of lipoprotein protein to the elastin. No significant lipid transfer occurred from the high density lipoproteins or chylomicrons. The amount of lipid taken up by plaque elastin was strikingly higher than by normal elastin and consisted mainly of cholesterol with over 80% of the cholesterol being cholesterol ester. The precondition for the lipid accumulation in plaque elastin appeared to be an altered amino acid composition of the elastin protein consisting of an increase in polar amino acids and a reduction in cross-linking amino acids. Subsequent treatment of lipoprotein-incubated arterial elastin with hot alkali and apolipoproteins did not reverse the binding of lipoprotein lipid to diseased elastin.

Topics: Amino Acids; Arteriosclerosis; Cholesterol; Chylomicrons; Elastin; Humans; Hydrolysis; Hyperlipidemias; In Vitro Techniques; Iodine Isotopes; Lipid Metabolism; Lipoproteins; Lipoproteins, LDL; Lipoproteins, VLDL; Protein Binding; Sodium Hydroxide; Trypsin

Topics: Animals; Arteries; Arteriosclerosis; Blood Proteins; Cells, Cultured; Cholesterol; Coronary Disease; Elastic Tissue; Elasticity; Elastin; Glycosaminoglycans; Haplorhini; Lipoproteins, HDL; Lipoproteins, LDL; Macaca; Microscopy, Electron; Muscle, Smooth

Topics: Amino Acids; Aorta; Arteriosclerosis; Autopsy; Collagen; Elastin; Histocytochemistry; Humans; Methods; Microscopy, Fluorescence; Molybdenum

Topics: Animals; Aorta; Arteriosclerosis; Cholesterol; Columbidae; Diet, Atherogenic; Elastin; Tritium

Topics: Animals; Aorta; Arteriosclerosis; Collagen; Diabetes Mellitus, Experimental; Diet, Atherogenic; Elastin; Rabbits; Time Factors

Topics: Aging; Animals; Aorta; Aorta, Abdominal; Aorta, Thoracic; Arteries; Arteriosclerosis; Collagen; DNA; Elastic Tissue; Elastin; Humans; Muscle, Smooth; Necrosis; Pulmonary Artery; Rats; Sutures; Swine; Wound Healing

Topics: Animals; Aorta; Aorta, Thoracic; Arteriosclerosis; Body Weight; Castration; Collagen; DNA; Elastin; Estradiol; Estrogens; Female; Menopause; Organ Size; Ovary; Proteins; Rats; Uterus

Topics: Amino Acids; Animals; Aorta; Arteries; Arteriosclerosis; Autoanalysis; Elastin; Humans; Kinetics; Potassium; Solubility; Swine

Topics: Abnormalities, Drug-Induced; Aminopropionitrile; Aneurysm; Animals; Arteriosclerosis; Bone Diseases; Collagen; Elastin; Female; Humans; Joint Diseases; Lathyrism; Paralysis; Pregnancy; Wound Healing

Topics: Animals; Aorta; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Collagen; Elastin; Estradiol; Hypertension; Male; Medroxyprogesterone; Organ Size; Proteins; Rats; Stress, Mechanical

Neutral, uncharged binding sites for calcium ions are proposed for elastin and collagen. The sites utilize, particularly from a conformational viewpoint, the most striking feature of the amino acid composition, that is, the high glycine content. Glycines favor the formation of beta-turns and associated conformations that are known, from studies on ion-transporting antibiotics, to interact with cations. By analogy with certain antibiotics, which are uncharged polypeptides and depsipeptides that bind cations by coordination with neutral acyl oxygens, it is proposed that calcium-ion binding also utilizes uncharged coordinating groups, i.e., neutral sites, in the protein matrix. The protein matrix, which becomes positively charged by virtue of the bound calcium ions, attracts neutralizing phosphate and carbonate ions, which then allow further calcium ion binding. The driving force is, therefore, the affinity of calcium ions for the neutral nucleation sites. The charge neutralization theory of calcification suggests a fundamental role of organic anions, for example sulfated mucopolysaccharides, in regulating bone formation and in retardation of atherosclerosis. The proposed mechanism contains elements that tend to unify several theories on the pathogenesis of atherosclerosis.

Topics: Arteriosclerosis; Binding Sites; Calcification, Physiologic; Calcinosis; Calcium; Carbonates; Collagen; Elastin; Glycine; Glycosaminoglycans; Models, Structural; Phosphates

Topics: Amino Acids; Aorta; Aortic Diseases; Arteriosclerosis; Edetic Acid; Elastin; Humans; Hydrochloric Acid; Hydrolysis; Male; Sodium Hydroxide

Elastin preparations from intimal layers and the media of normal and atherosclerotic human aortae were analyzed for protein and lipid content. In atherosclerotic aortae, elastin from plaques was compared with elastin from adjacent normal appearing areas of the same aorta. Arterial elastin purified by alkaline extraction appeared to be a protein-lipid complex containing free and ester cholesterol, phospholipids, and triglycerides. The lipid component of normal arterial elastin was small (1-2%). With increasing severity of atherosclerosis, there was a progressive accumulation of lipid in intimal elastin from plaques, reaching a mean lipid content of 37% in severe plaques. The increase in the lipid content of plaque elastic preparations was mainly due to large increases in cholesterol, over 80% of which was cholesteryl ester. This deposition of cholesterol in plaque elastin accounted for 20-34% of the total cholesterol content of the plaque. The increased lipid deposition in plaque elastin was associated with alterations in the amino acid composition of plaque elastin. In elastin from plaque intima, the following polar amino acids were increased significantly: aspartic acid, threonine, serine, glutamic acid, lysine, histidine, and arginine; whereas, cross-linking amino acids: desmosine, isodesmosine, and lysinonorleucine were decreased significantly. The amino acid and lipid composition of elastin from normal appearing aortic areas was comparable to that of normal arterial elastin except for intimal elastin directly adjacent to and medial elastin directly below the most severe plaques.The data indicate that the focal lipid deposition in early atherosclerotic plaques is due to a large extent to lipid accumulations in altered elastin protein of localized intimal areas. Continued lipid deposition in altered elastin appears to contribute substantially to the progressive lipid accumulation in the plaque. The study suggests that elastin of intimal elastic membranes may play an important role in the pathogenesis and progression of atherosclerosis.

Topics: Adolescent; Adult; Aged; Aorta; Arginine; Arteriosclerosis; Aspartic Acid; Cholesterol; Elastin; Esters; Female; Glutamates; Histidine; Humans; Lipids; Lung; Lysine; Male; Middle Aged; Phospholipids; Proteins; Serine; Threonine; Triglycerides; Tritium

Topics: Adolescent; Adult; Aorta, Thoracic; Arteriosclerosis; Calcinosis; Calcium; Cholesterol; Elasticity; Elastin; Fatty Acids; Humans; Lipid Metabolism; Phosphates; Pressure; Protein Binding

Topics: Adolescent; Adult; Age Factors; Aged; Aorta; Arteries; Arteriosclerosis; Black People; Calcium; Cerebral Arteries; Cerebrovascular Disorders; Child; Child, Preschool; Cholesterol; Collagen; Coronary Disease; Coronary Vessels; Elastin; Female; Hexosamines; Histocytochemistry; Humans; Infant; Infant, Newborn; Lipids; Male; Middle Aged; Phospholipids; Sex Factors; South Africa; Thrombosis; Triglycerides; White People

Topics: Animals; Antibody Formation; Antigen-Antibody Reactions; Arteriosclerosis; Blood Proteins; Calcinosis; Cholesterol; Diet, Atherogenic; Elastic Tissue; Elastin; Rabbits

Topics: Age Factors; Aging; Animals; Arteriosclerosis; Collagen; Elastin; Environment; Environmental Exposure; Humans; Hyaluronic Acid; Longevity; Mice; Molecular Biology

Topics: Arteries; Arteriosclerosis; Elastin; Femoral Artery; Humans; Iliac Artery; In Vitro Techniques; Microbial Collagenase; Peptide Hydrolases; Perfusion; Time Factors; Trypsin; Vascular Diseases

Topics: Aging; Amino Acids; Animals; Aorta; Arginine; Arteriosclerosis; Aspartic Acid; Cattle; Elastin; Glutamates; Lysine; Rabbits

Topics: Animals; Aorta; Aorta, Abdominal; Aorta, Thoracic; Arteriosclerosis; Chickens; Cholesterol; Elastin; Microscopy, Electron

Topics: Animals; Aorta; Aorta, Abdominal; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Cats; Cattle; Collagen; Cricetinae; Diet, Atherogenic; Dogs; Elastin; Guinea Pigs; Haplorhini; Hydroxyproline; Mice; Rabbits

Topics: Aged; Arteriosclerosis; Calcium; Edetic Acid; Elastic Tissue; Elastin; Enzyme Activation; Humans; Indicators and Reagents; Pancreatic Elastase

Topics: Aged; Aorta, Abdominal; Aortic Aneurysm; Aortic Rupture; Arteriosclerosis; Biomechanical Phenomena; Collagen; Elasticity; Elastin; Humans; Iliac Artery; Mesenteric Arteries; Middle Aged; Pressure; Proteins; Renal Artery

Topics: Animals; Aorta; Aorta, Thoracic; Arteriosclerosis; Blood Pressure; Body Weight; Collagen; Desoxycorticosterone; Elasticity; Elastin; Hypertension; Male; Organ Size; Rats

Topics: Amino Acids; Arteriosclerosis; Blood Circulation; Blood Flow Velocity; Computers; Connective Tissue; Elasticity; Elastin; Humans; Lipid Metabolism; Models, Chemical; Peptides; Rheology; Vascular Diseases

Topics: Adenine Nucleotides; Arteriosclerosis; Blood Platelets; Cathepsins; Chromatography, Gel; Elastin; Humans; Iodine Isotopes; Pancreatic Elastase; Surface-Active Agents

Topics: Animals; Arteriosclerosis; Elastic Tissue; Elastin; Electrophoresis; Mammals; Pancreas; Pancreatic Elastase; Spectrophotometry; Staining and Labeling; Trypsin

Topics: Arteriosclerosis; Calcium; Cholesterol; Collagen; Elastin; Glycosaminoglycans; Humans; Hyperlipidemias; Hypertension; Lipid Metabolism; Lipoproteins; Smoking; Thrombin

Topics: Adrenal Glands; Age Factors; Animals; Aortic Diseases; Arteriosclerosis; Blood Vessels; Calcinosis; Cholesterol; Elastin; Endarteritis; Epinephrine; Female; Freund's Adjuvant; Glycoproteins; Glycosaminoglycans; Glycoside Hydrolases; Humans; Injections, Intravenous; Lipase; Lipid Metabolism; Male; Necrosis; Pancreatic Elastase; Rabbits; Sex Factors; Stress, Physiological; Thyroxine; Time Factors; Transplantation, Homologous

Topics: Animals; Antigens; Arteries; Arteriosclerosis; Autoantibodies; Autoimmune Diseases; Elastin; Fluorescent Antibody Technique; Lipids; Rabbits

Topics: Aging; Amino Acids; Animals; Animals, Newborn; Arteries; Arteriosclerosis; Autoradiography; Cholesterol; Dogs; Elastin; Fetus; Haplorhini; Humans; Lipids; Swine; Tritium

Topics: Animals; Aorta, Abdominal; Arteries; Arteriosclerosis; Basement Membrane; Disease Models, Animal; Elastic Tissue; Elastin; Epithelium; Hydrochloric Acid; Microscopy, Electron; Muscle, Smooth; Rats

Topics: Anatomy, Comparative; Animals; Aorta; Aorta, Abdominal; Aorta, Thoracic; Arteriosclerosis; Body Weight; Cats; Cattle; Collagen; Dogs; Elastin; Hemodynamics; Horses; Mice; Pressure; Rabbits; Rats; Sheep; Species Specificity; Swine; Vasa Vasorum

Topics: Aneurysm; Animals; Aorta, Thoracic; Arteries; Arteriosclerosis; Cardiovascular Diseases; Collagen; Copper; Deficiency Diseases; Elastin; Pedigree; Rupture; Swine; Vascular Diseases

Topics: Amino Acids; Animals; Antigens; Aorta; Arteries; Arteriosclerosis; Chromatography, Gel; Elastic Tissue; Elastin; Electrophoresis; Solubility; Swine

Topics: Adult; Age Factors; Aged; Alanine; Amino Acids; Animals; Aorta; Arteries; Arteriosclerosis; Elastin; Humans; Infant; Infant, Newborn; Lysine; Methods; Middle Aged; Phenylalanine; Rabbits; Tyrosine

Topics: Arteriosclerosis; Elastin; Humans

Topics: Animals; Aorta; Arteriosclerosis; Autoimmune Diseases; Elastic Tissue; Elastin; Proteins; Rabbits; Swine

Topics: Adult; Aged; Amino Acids; Animals; Arteriosclerosis; Elastin; Humans; Infant; Middle Aged; Rabbits

Topics: Aging; Arteriosclerosis; Carbon; Coronary Disease; Coronary Vessels; Elastin; Glycosaminoglycans; Staining and Labeling

Topics: Aging; Arteriosclerosis; Collagen; Elastic Tissue; Elastin; Histocytochemistry; Humans; Microscopy, Fluorescence; Microscopy, Polarization; Renal Artery; Staining and Labeling

Topics: Adolescent; Adult; Age Factors; Aging; Arteries; Arteriosclerosis; Autopsy; Child; Child, Preschool; Coronary Vessels; Elastin; Female; Fibroblasts; Hemodynamics; Histiocytes; Humans; Infant; Infant, Newborn; Male; Microscopy, Electron; Muscle Development; Muscle, Smooth; Sex Factors; Staining and Labeling

Topics: Aminopropionitrile; Animals; Aorta; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Collagen; Depression, Chemical; Elastin; Female; Fetal Diseases; Fetus; Hydroxyproline; Mice; Microscopy, Electron; Nitriles; Pregnancy; Pregnancy, Animal

Topics: Adolescent; Adult; Age Factors; Aged; Aorta; Arteriosclerosis; Blood Vessels; Chemical Phenomena; Chemistry; Elasticity; Elastin; Female; Fluorescence; Humans; Male; Middle Aged; Pigments, Biological; Proteins

Topics: Animals; Antibodies; Antigens; Arteriosclerosis; Autoantibodies; Cattle; Elastin; Rabbits

Topics: Animals; Aorta; Arteriosclerosis; Body Weight; Cholesterol; Collagen; Elastin; Lipids; Liver; Lung; Male; Myocardium; Peptide Hydrolases; Phospholipids; Rabbits

Topics: Arteriosclerosis; Collagen; Elastic Tissue; Elastin; Histocytochemistry; Humans; Microscopy, Fluorescence; Microscopy, Polarization; Renal Artery; Staining and Labeling

Topics: Animals; Aorta; Arteriosclerosis; Blood Proteins; Carbon Isotopes; Cell Nucleus; Collagen; Elastin; Liver; Microsomes, Liver; Mitochondria, Liver; Protein Biosynthesis; Rabbits

Topics: Animals; Aorta; Arteriosclerosis; Bird Diseases; Cholesterol; Chromatography, Gas; Collagen; Connective Tissue; Elastin; Fatty Acids; Hexosamines; Histocytochemistry; Lipids; Phospholipids

Topics: Arteriosclerosis; Blood Vessels; Elastic Tissue; Elastin; Humans; Pancreatic Elastase

Topics: Animals; Arteriosclerosis; Elastin; Humans; Lipoprotein Lipase; Pancreas; Pancreatic Elastase

Topics: Adolescent; Aging; Amino Acids; Aorta; Aorta, Thoracic; Arteriosclerosis; Atherosclerosis; Child; Elastic Tissue; Elastin; Geriatrics; Histocytochemistry; Humans; Infant

Topics: Adult; Aged; Animals; Antibodies; Antibodies, Anti-Idiotypic; Arteriosclerosis; Elastin; Erythrocytes; Hemagglutination Tests; Humans; In Vitro Techniques; Middle Aged; Rabbits

Topics: Arteries; Arteriosclerosis; Black or African American; Black People; Calcium; Collagen; Elastin; Hexosamines; Humans; South Africa; White People

Topics: Animals; Aorta; Arteries; Arteriosclerosis; Cattle; Cholesterol; Collagen; Corn Oil; Diet; Diet, Atherogenic; Elastin; Fats; Fatty Acids; Food, Formulated; Lipid Metabolism; Liver; Oils; Pathology; Phospholipids; Proteins; Research; Swine; Zea mays

Topics: Arteriosclerosis; Elastic Tissue; Elastin; Humans; Hyperlipidemias; Lipoproteins; Pancreatic Elastase; Pancreatic Extracts; Peptide Hydrolases; Serine Endopeptidases

Topics: Arteriosclerosis; Collagen; Coloring Agents; Elastin; Enzyme Inhibitors; Histocytochemistry; Oxazines; Pancreatic Elastase; Pancreatic Extracts; Research; Staining and Labeling

Twelve peripheral arteries are described in 59 patients of all ages. Accumulation of ground substance in the media, accompanied by small foci of calcification of the internal elastic lamina, was found in the large leg arteries of young adults, and progressively in a wider series of arteries throughout life. This picture showed no relationship to hypertension, to Mönckeberg's sclerosis, or to the development of atheroma. A notable quantity of ground substance may be a feature of early intimal development, and of a thickened intima in adult life, and probably the major constituent of an organizing thrombus. Organizing thrombi were apparently incidental findings at several sites even in young adults, and showed no association with the state of the arterial wall beneath the lesion, the wall being in fact normal, though accumulated mucopolysaccharide was always present. Atheroma increases with age, and its focal incidence gives way to confluence in the arteries of the leg. Occlusive peripheral artery atheroma was found only in cases where the cause of death was severe atheroma, e.g., coronary artery disease and abdominal aortic aneurysm, or in myxoedema, in which the incidence of occlusive lesions may differ from that in severe generalized atheroma. Elastic tissue is described in all coats of the artery wall, with some variants of the common pattern. The musculo-elastic cushion is not seen after adolescence, and it is suggested that the cushion represents the growing point of the artery. Longitudinal muscle bundles are almost confined to the popliteal artery, where they may form an essential buttress for a large branching artery subject to unusual external stresses. The functions and origin of the ground substance are discussed.

Topics: Adolescent; Adult; Aging; Aorta; Arteries; Arteriosclerosis; Brachial Artery; Carotid Arteries; Child; Elastic Tissue; Elastin; Femoral Artery; Fetus; Fingers; Geriatrics; Growth; Histology; Humans; Hypertension; Infant; Male; Mesenteric Arteries; Microscopy; Pathology; Popliteal Artery; Proteins; Renal Artery; Thrombosis; Tunica Intima; Tunica Media; Vertebral Artery

Topics: Animals; Arteriosclerosis; Blood; Coloring Agents; Elastin; Endopeptidases; Enzyme Inhibitors; Oxazines; Pancreatic Elastase; Pancreatic Extracts; Pancreatic Juice; Proteins; Rabbits; Rats; Research; Staining and Labeling

Topics: Aorta; Apatites; Arteriosclerosis; Calcification, Physiologic; Elastic Tissue; Elastin; Electrons; Geriatrics; Humans; Microscopy; Microscopy, Electron; Proteins

Topics: Animals; Arteriosclerosis; Cattle; Clinical Enzyme Tests; Dogs; Edetic Acid; Ehlers-Danlos Syndrome; Elastin; Electrophoresis; Enzyme Inhibitors; Geriatrics; Glycoproteins; Guinea Pigs; Haplorhini; Horses; Meat; Mice; Pancreatic Elastase; Peptide Hydrolases; Poultry; Rabbits; Rats; Research; Serum Globulins; Sheep; Sheep, Domestic; Swine

Topics: Animals; Aorta; Arteriosclerosis; Chickens; Elastin; Lipoproteins; Meat

Topics: Aorta; Aortic Diseases; Arteriosclerosis; Disease; Elastin; Humans; Proteins

Topics: Aorta; Arteriosclerosis; Carbohydrate Metabolism; Carbohydrates; Collagen; Elastin; Humans; Hyalin; Proteins

Topics: Adenosine Triphosphate; Aorta; Arteries; Arteriosclerosis; Cardiovascular System; Elastin; Humans; Phosphoric Monoester Hydrolases

Topics: Arteriolosclerosis; Arteriosclerosis; Calcium, Dietary; Elastin; Humans