Fig 5. Model of reverse cholesterol transport in the artery intima.

White arrows indicate the movement of HDL particles into and out of the intima. Exchange of apoA-I (green arrows) is measured by the HAE assay, with the exchangeable pool of HDL coming primarily from the α-particles. This exchangeable pool of apoA-I is the precursor to preß-1 HDL, the primary substrate for de novo HDL biogenesis (red arrow) via ABCA1, residing on cholesterol-loaded macrophages (MΦ).