Figure 4.

Species of lipoproteins in IDL (Upper) and LDL (Lower) fractions from apo E- and HL-doubly deficient mice, separated by gel filtration. The larger species of 600 Å–1,300 Å diameter (Left) are characterized by an electron-opaque core, with an electron-lucent region abutting the wall (open arrowheads). Some particles are multilamellar (arrows). The smaller species (Right) resemble the spherical/rectangular particles of total IDL and LDL (see Fig. 2), with a few oblong or irregular particles in the latter (arrows). (×87,300.)