Phospholipid Studies of Different Serum Lipoproteins Employing P 32

Abstract

Summary

1. Administration of P₃₂ to humans by mouth resulted in labelling of the α₁ α₂ and β lipoproteins separated by zone electrophoresis in a starch supporting medium. 2. Both phospholipid phosphorus and radioactivity of α₂ lipoprotein fraction increased after ordinary meals. 3. Specific activities of the different lipoproteins were very similar even at various time intervals following the oral radioactive phosphate. The only exception was a slightly higher specific activity for the α₁ lipoprotein in certain sera taken at early times. 4. In vitro experiments demonstrated transfer of phospholipid radioactivity from labelled β lipoproteins to unlabelled α₁ lipoproteins; also from labelled α₁ lipoproteins to unlabelled β lipoproteins.