Formation of lipoprotein-X. Its relationship to bile compounds.
In this study we have demonstrated that in native bile, lipids are organized in the form of a lipoprotein (bile LP) carrying albumin as apoprotein. The lipid composition of bile LP is almost identical to lipoprotein-X (LP-X, the characteristic lipoprotein of cholestasis). However, it differs from LP-X inits protein/lipid ratio and immunological and electrophoretic characteristics. Bile lipoprotein can be converted into "LP-X-like" material in vitro by adding albumin or serum to native bile. The LP-X-like material formed in vitro has physicochemical and chemical characteristics similar or identical to LP-X isolated from serum. As bile lipoprotein can be converted into LP-X-like material by the addition of albumin to bile, LP-X can be converted into bile-LP-like particles by adding bile salts to a LP-X-positive serum. Furthermore, experimental connection of the common bile duct to the vena cava is followed after a few hours by the appearance of LP-X-like material in the plasma. These facts taken together strongly suggest that bile LP is a precursor lipoprotein for LP-X and that it refluxes into the plasma pool under cholestatic conditions.
D000818:Animals; D001646:Bile / Q000378:metabolism*; D001647:Bile Acids and Salts / Q000378:metabolism*; D001652:Bile Ducts / Q000502:physiology; D001665:Binding Sites; D002404:Catheterization; D002784:Cholesterol / Q000097:blood; D004285:Dogs; D006801:Humans; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D008074:Lipoproteins / Q000097:blood / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D010743:Phospholipids / Q000097:blood; D011233:Precipitin Tests; D011485:Protein Binding; D014280:Triglycerides / Q000097:blood
D001647:Bile Acids and Salts; D008074:Lipoproteins; D010743:Phospholipids; D014280:Triglycerides; D002784:Cholesterol