Lecithin:cholesterol acyltransferase and cholesteryl ester transfer activity from the isolated perfused rabbit liver

Lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester (CE) transfer activity accumulate linearly in the recirculated medium of the isolated perfused rabbit liver. The appearance of both activities in the perfusate was blocked by the addition of 10 microM colchicine, indicating that these two proteins are synthesized and secreted by the liver. CE transfer activity catalyzed the net transport of cholesteryl ester from high density lipoprotein (donor) to very low and low density lipoproteins (acceptor), both in the perfusate medium and in whole rabbit blood plasma. The activity of LCAT in the perfusate was dependent on the presence of the major protein of the high density lipoprotein class, apoA-I. The similar properties of LCAT and CE transfer activity in rabbit liver perfusate and plasma, compared to these same activities in human blood, suggest that the rabbit is an appropriate model for the study of the cholesterol transport system in man.