DEFICIENCY OF ACYL COA CHOLESTEROL ACYL TRANSFERASE-ACTIVITY IN SUNCUS LIVER

We reported previously that apolipoprotein B is not actively secreted from suncus liver. In the present study we have investigated the hepat ic cholesterol metabolism, which plays a critical role in the secretio n of apo B. We found that the activity of 3-hydroxy-3-methylglutaryl c oenzyme A reductase in suncus Liver is high and that acyl-coenzyme A: cholesterol acyltransferase (ACAT) activity is almost absent in contra st to rats. As a result, the hepatic content of cholesterol ester, upo n which apoprotein B secretion partly depends, is very low in suncus. The deficiency of ACAT activity may cause the defect in active secreti on of apoprotein B-containing lipoproteins in suncus.