title: Composition and genesis of calcium deposits in atheroma plaques.
abstract: The composition of atheromatous plaque determines its progression toward rupture or thrombosis. Although its histopathological structure has been widely studied, little attention has been paid to its structural and chemical composition and even less to its mineral component. Thirty-three atheromatous plaques were obtained by carotid thromboendarterectomy. Three types of materials were observed under polarized light microscopy: apatite crystals in the form of glomeruli (dark with plane polarized illumination and greensh with cross-polarized illumination); fibrous-like cholesterol (uncolored or grayish with plane-polarized illumination); and amorphous organic material as brownish deposits. SEM-EDX analysis showed an abundance of phosphorus and calcium in sufficient quantities to form calcium phosphates, and appreciably reduced levels of sodium. X-ray diffraction results differentiated samples into three groups: group I with predominance of hydroxyapatite-type crystals, group II with crystalline material containing an amorphous component, and group III with wholly amorphous material. The most abundant mineral in atheromatous plaque is hydroxyapatite, on which crystals of cholesterol and lipid nuclei are deposited, stratifying the plaque into layers that reflect the different stages of its formation. The difference in calcium and sodium concentrations between arteries with and without atheromata may indicate an important relationship in the pathophysiological development of calcium deposits.
authors.affiliation: Department of Vascular Surgery, "Virgen de la Victoria" Hospital, Malaga University , Malaga , Spain .
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Lara
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ros
authors.forename: Manuel
authors.initials: M
authors.lastname: Sierra
authors.forename: Carlos
authors.initials: C
authors.lastname: Dorronsoro
authors.forename: José
authors.initials: J
authors.lastname: Aguilar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000032:analysis; D002339:Carotid Arteries / Q000737:chemistry* / Q000601:surgery / Q000648:ultrastructure; D002340:Carotid Artery Diseases / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D002784:Cholesterol / Q000032:analysis; D003460:Crystallization; D017886:Durapatite / Q000032:analysis; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008859:Microscopy, Polarization; D008875:Middle Aged; D010758:Phosphorus / Q000032:analysis; D058226:Plaque, Atherosclerotic; D012964:Sodium / Q000032:analysis; D013052:Spectrometry, X-Ray Emission; D017131:Thrombectomy; D061205:Vascular Calcification / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D014961:X-Ray Diffraction
chemical_list: D010758:Phosphorus; D017886:Durapatite; D002784:Cholesterol; D012964:Sodium; D002118:Calcium