Ultrastructural appearance of EPCs after 30 minute of HDL-HRP internalization.

<p><b>A</b>) HDL-HRP particles can be seen at the cell surface (black arrow), the various sizes of HDL-HRP positive endosomal vesicles (E) are present beneath the cell membrane and close to the Golgi apparatus (G). <b>B</b>) HDL-positive and -negative MVBs (MVBs, asterisk) are visible. The white arrowhead indicates HDL-negative MVBs representing an early stage of lipid internalization; lipid droplets (Li) appear unstained. <b>C</b>) Lysosomes (L) shows intraluminal HDL-HRP particles. <b>D</b>) The RER is HDL-HRP negative while two invaginations of the plasma membrane (black arrowheads) show a strong reaction. (Scale bar: A, C = 1 µm; B, D = 0.5 µm).