Intestinal absorption of polyenephosphatidylcholine in man

The metabolic fate of 1 g of 'H/'4C-labeled dilinoleoglycerophosphocholine was studied in five patients after oral administration.The 'H label was in choline and I4C was in the two linoleic acid residues.More than 90% of both isotopes was absorbed from the intestine.Seventy to 90% of the 'H radioactivity in blood was linked to phosphatidylcholine (PC) whereas I4C was associated with both PC and nonpolar lipids.At peak activity, the 'H/14C ratio of plasma PC was twice that of oral PC; this suggests that most oral PC was hydrolyzed to lysolecithin before absorption.The mean maximum concentration in total blood volume was 20% of the administered dose for 'H and 28% for I4C.Examination of lipoproteins revealed that the specific activity of PC in high density lipoprotein (HDL) was 2 to 6 times higher than in apoB-containing lipoproteins, and 2 to 20 times than that of red blood cells or total blood.Thus, absorbed PC seemingly was incorporated preferentially into the HDL fraction of plasma.-Zierenberg,O.