The external elastic lamina (EEL) serves as a barrier for cells and macromolecules between the media and adventitia in the vascular wall. We evaluated the morphological changes and quantitative assessments of the EEL architecture in the coronary circulation of pigs fed with a high cholesterol diet. Confocal microscopy analysis of the EEL from hypercholesterolemic coronary arteries revealed an altered pattern characterized by fragmentation and disorganization of the EEL associated with an increase in the thickness. Computerized digital analysis of the images obtained by confocal scanning microscopy demonstrated that compared to normal coronary arteries, the EEL of hypercholesterolemic coronary arteries decreased in the percentage of their elastin content (30.80 +/- 1.64% vs. 47.85 +/- 1.82%, p = 0.001). The percentage of elastin content was negatively correlated with the vessel wall area (r = -0.82, p = 0.001). The immunoreactivity for matrix metalloproteinase-3 (MMP-3) increased in cholesterol-fed coronary arteries, predominantly in the neointima and adventitia. This study demonstrates that experimental hypercholesterolemia induced ultrastructural changes of the EEL in coronary circulation. The EEL may also be an atherosclerosis-prone area compared with the intima. The EEL may play an important role in the development of structural changes which characterizes the early phase of coronary atherosclerosis and vascular remodeling.
Animal ; Arteries/ultrastructure ; Arteries/enzymology ; Coronary Vessels/ultrastructure* ; Coronary Vessels/enzymology ; Elastic Tissue/ultrastructure* ; Elastic Tissue/enzymology ; Female ; Hypercholesterolemia/pathology* ; Hypercholesterolemia/enzymology ; Stromelysin 1/metabolism ; Swine

Atherosclerosis is the most severe problem in the high-pressure systemic circulation and similar changes also occur in the high-pressure loading valve. This study was designed to test the hypothesis that early atherosclerosis, induced by a high cholesterol diet in rabbits, is characterized by significant ultrastructural change in the elastic laminae of the aortic valve. However, it is not known whether this process is also taking place in the cardiac valve at the early stage of atherosclerosis. Animals were fed either a high cholesterol diet (n = 5) or a control diet (n = 5) for 10-12 weeks. Histologic analysis demonstrated that subendothelial thickening and foam-cell infiltration were evident in the arterialis of aortic valves. Confocal microscopy revealed an altered pattern characterized by fragmentation and disorganization of the arterialis elastic laminae of hypercholesterolemic valves. Computerized digital analysis of the images obtained by confocal scanning microscopy demonstrated that compared to normal valves, the arterialis elastic laminae of hypercholesterolemic valves decreased in percentage of their elastin content (29.03 +/- 1.10% vs. 42.94 +/- 1.35%, p = 0.023). Immunohistochemical staining for matrix metalloproteinase-3 (MMP-3) revealed MMP-3 immunoreactivity was increased in hypercholesterolemic valves, predominantly in the arterialis. This study demonstrated that early atherosclerosis, induced by a high cholesterol diet in rabbits, is characterized by significant ultrastructural change in the elastic laminae of the aortic valve. The arterialis endothelium of the aortic valve may be a more atherosclerosis-prone area compared with the ventricularis. The presence of ultrastructural defect in the elastic laminae may play a role in chronic degenerative change and a resultant valvular dysfunction.
Animal ; Aortic Valve/ultrastructure* ; Elastic Tissue/ultrastructure* ; Hypercholesterolemia/pathology* ; Male ; Microscopy, Confocal ; Rabbits ; Stromelysin 1/metabolism

OBJECTIVEThe purpose of this study was to observe the ultrastructure of the fibroblasts, collagen and elastic fibers in vocal fold polyps.

METHODSTen vocal fold polyps and 3 normal vocal fold specimens obtained from total laryngectomy were studied by means of transmission electron microscope and scanning electron microscope.

RESULTSThe result showed that in vocal fold polyps, the quantity of fibroblasts increased and there were abundant organelles, suggesting that the fibroblast were in the status of activation. As the main cell to produce lamina propria extracellular matrix, the representation suggested that the extracellular matrix metabolism was active. Leucocytes soakage was observed, suggesting that the inflammation may play a role in the lesion. It was found by scanning electron microscopy that in case of lesions, collagen fibers and elastic fibers arrayed irregularly.

CONCLUSIONSUnder pathologic circumstance, fibroblasts, collagen and elastic fibers altered in morphology, which possibly induced the functional alteration.

Adult ; Case-Control Studies ; Collagen ; ultrastructure ; Elastic Tissue ; ultrastructure ; Female ; Fibroblasts ; ultrastructure ; Humans ; Laryngeal Diseases ; pathology ; Male ; Middle Aged ; Polyps ; pathology ; ultrastructure ; Vocal Cords ; pathology ; ultrastructure