LECITHIN-CHOLESTEROL ACYLTRANSFERASE AND LIPOPROTEIN ABNORMALITIES OF OBSTRUCTIVE-JAUNDICE

The plasma lipoprotein abnormalities in obstructive jaundice were studied to test the hypothesis that the abnormalities would correlate with plasma lecithin-cholesterol acyltransferase activity. Very-low-density lipoproteins (VLDL) were normal in composition and had a normal pre-.beta. electrophoretic mobility when lecithin-cholesterol acyltransferase activity was high. When it was low, VLDL had abnormal compositon and ran in the .beta. position. With high lecithin-cholesterol acyltransferase activity, low-density lipoprotein (LDL) was normal and cholestatic LDL (LP-X) was not found. With low lecithin-cholesterol acyltransferase activity up to 3 LDL fractions were found: large triglyceride-rich particles, LP-X and a triglyceride-rich cholesteryl ester-poor particle of normal dimensions. High-density lipoprotein (HDL) concentrations correlated with lecithin-cholesterol acyltransferase activity and HDL were normal in composition and EM appearance when the activity was high. When lecithincholesterol acyltransferase activity was low, HDL was abnormal in composition and stacked discs were seen on EM as well as normal spherical particles. Low lecithin-cholesterol acyltransferase activity may cause at least some of the lipoprotein changes of obstructive jaundice.