Evidence that reverse cholesterol transport occurs in vivo and requires lecithin-cholesterol acyltransferase.
The transport of cholesterol from extrahepatic tissues into plasma (reverse cholesterol transport) and the possible requirement for lecithin:cholesterol acyltransferase was examined in the rat. One hour after removal of the liver plasma cholesterol ester concentrations were significantly increased by 20%, whereas free cholesterol concentrations were unchanged. The lecithin:cholesterol acyltransferase inhibitor, 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) was administered to eviscerated rats. It inhibited plasma lecithin:cholesterol acyltransferase activity by 90% which in turn totally prevented the increase in plasma cholesterol ester concentrations. In addition, heat-inactivated plasma from DTNB-treated eviscerated rats was 50% more reactive toward a standard source of lecithin:cholesterol acyltransferase compared to plasma from control or untreated eviscerated rats. These data suggest that in the rat a reactive lecithin:cholesterol acyltransferase substrate is formed extrahepatically. Together with lecithin:cholesterol acyltransferase, this reactive substrate removes cholesterol from peripheral tissues.
D000818:Animals; D001692:Biological Transport; D002784:Cholesterol / Q000378:metabolism*; D002788:Cholesterol Esters / Q000097:blood; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D007700:Kinetics; D008075:Lipoproteins, HDL / Q000097:blood; D008099:Liver / Q000378:metabolism*; D008297:Male; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D002788:Cholesterol Esters; D008075:Lipoproteins, HDL; D002784:Cholesterol; D004228:Dithionitrobenzoic Acid; D007862:Phosphatidylcholine-Sterol O-Acyltransferase