Increase in selective hepatic uptake of high-density lipoprotein cholesteryl esters in the fasted rabbit

Abstract

The selective hepatic uptake of high-density lipoprotein cholesteryl esters was determined in primary hepatocyte cultures of cells from normal, cholestyramine-fed and 48-h-fasted rabbits. The HDL was labeled in the apoprotein moiety with [ 14C]sucrose and in the core component with [ 3H]cholesteryl linoleyl ether. The uptake of the apoprotein label did not differ between groups (indicating no change in holoparticle HDL uptake), but in contrast, the uptake of the cholesteryl ether label was significantly increased in hepatocytes from cholestyramine-fed and fasted animals. After 40 h of culture, the ratio of 3H to 14C uptake was 4.96 in controls cells, 7.15 in cholestyramine-treated cells and 10.24 in fasted hepatocytes from short-term fasted animals. Thus short-term fasting was associated with a 2-fold increase in the selective hepatic uptake of HDL core components, indicating the selective hepatic uptake of HDL cholesteryl esters is a physiologically responsive process.