Figure 7.

Transverse, osmicated electron micrographs showing the deposition of lipid within the distal thoracic aortic wall of SR-BI^-/-/ApoeR61^h/h mice aged 1-60 days old (do). Variably sized, intracellular lipid can be observed within endothelial cells (C, E, G-I) and within smooth muscle cells (B, C, H-I) directly beneath the internal elastic lamina (IEL) across all age groups, (yellow asterisks). At 1do, lipid is being engulfed by endothelial cells (A, red asterisks). Within an intercostal ostial ridge, lipid droplets are pictured accumulating within a smooth muscle cell (F, yellow arrow). At 60do, an accumulation of intraendothelial, clustered and variably sized lipid droplets admixed with calcified/mineralized debris (black amorphous material) is indicative of early atherosclerotic lesion formation (J). Scale, 500 nm (A–E and G–J) and 2 µm (F).