Liquid crystalline lipid in the plasma of humans with biliary obstruction.

Plasma lipoprotein characteristics were evaluated in a group of patients with obstructed biliary tracts. A 1:1 molar lecithin-free cholesterol liquid crystal phase was observed in the low density flotation region of these patients. The smectic nature of this mesophase was confirmed by electron microscopy, polarized microscopy, and low angle X-ray scattering. A small amount of protein was associated with these liquid crystals, some of which appeared to be components of normal very low and high density lipoproteins. The composition and physical properties of the very low and high density lipoproteins from these obstructed patients differed from normal as well. Aberrant apoprotein patterns were observed for both obstructed very low and high density lipoproteins. A beta-electrophoretic migration was observed for a component of these two lipoprotein groups.