Electron micrographs of the MCA.

<p>(A) Sham operated rabbit on a normal diet showing continuous endothelial cells (EC) (B) Hypertension only rabbit, showing a pyknotic cell (arrow) in the endothelial layer (EC). (C) Hypercholesterolemia plus sham rabbit, showing large intracellular vacuoles (V) in endothelial cells. (D) Hypertension plus hypercholesterolemia rabbit, showing breaks in the basement membrane (BR), and a large extracellular space (S) between the basement membrane and the underlying smooth muscle cells. (E) Hypertension plus hypercholesterolemia rabbit, showing a pyknotic cell among the endothelial layer (arrow), and presence subendothelial foam cells (FC). (F) Higher magnification of a foam cell in E, showing intracellular vacuoles, and extracellular spaces (S) containing collagen fibrils. Scale: A = 1 µm, B–D = 0.5 µm, E = 2 µm, F = 0.2 µm.