Cholesterol and calcium are prominant components within human atherosclerotic lesions. Both accumulate predominantly within the central core region of lesions. Because of similarities in some crystallographic faces of cholesterol monohydrate and calcium apatite, it has been previously proposed that deposition of one may nucleate the deposition of the other.
In this study, we have used the technique of confocal fluorescence microscopy to assess the spatial orientation of cholesterol in association with calcium mineral. Localization of cholesterol within mineral was carried out by staining cholesterol with the fluorescent probe, filipin.
With this technique, it was possible to localize cholesterol associated with the surface of hydroxyapatite seeds, cholesterol incorporated within calcium phosphate-cholesterol agglomerates produced in vitro, and cholesterol within apatite isolated from human atherosclerotic lesions.
The presence of cholesterol within the center of calcified granules from atherosclerotic plaque suggests that cholesterol or associated lipids may act to nucleate the deposition of apatite. Confocal fluorescence microscopy should be a useful technique by which to study the relationship of cholesterol associated with calcium minerals that occur not only in atherosclerotic blood vessels, but also in gallstones, and calcified cardiac valves.
Laboratory Investigation 12/1994; 71(5):782-7. · 3.83 Impact Factor