Apoprotein profile of plasma and chylous ascites lipoproteins

Plasma and chylous ascites lipoproteins were compared in a rare case of exudative enteropathy associated with stenosis of the thoracic duct. All ascites lipoproteins separated by ultracentrifugation showed a much higher triglyceride/protein ratio and a lower cholesterol ester content than their plasma counterparts. Polyarcylamide gel electrophoresis of apoproteins before and after fractionation on Sephadex G-200 essentially showed, compared to normal plasma, a reduction of apoprotein C in VLDL and HDL particularly obvious for apoCIII1 and CIII2. Ascites lipoproteins were characterized by an increased apoA content in chylomicrons, VLDL and LDL and a reduced percentage of apo CII and CIII1, mostly in chylomicrons, VLDL and HDL. The differences in composition between plasma and ascites might be explained by different origins for the various apoprotein subfractions. The transsudation of chyle into the abdominal cavity might divert some peptides of intestinal origin from their normal entry into the circulation.