Reverse cholesterol transport in the rat. Studies using the isolated perfused spleen in conjunction with the perfused liver.
1. A new method combining the use of an isolated perfused extrahepatic tissue with a perfused liver was developed as a model system for the study of reverse cholesterol transport. Rat spleens, initially labelled in vivo with [3H]cholesterol, were perfused for 3 h with whole blood. The spleen was then replaced with an isolated rat liver, whose uptake of cholesterol from the spleen-derived blood and excretion of cholesterol into bile constituents were determined. 2. During spleen perfusion, a net release of cholesterol mass and radioactivity to lipoproteins was observed. 3. During liver perfusion, there was also a rapid exchange or transport of unesterified cholesterol between high-density lipoprotein (HDL) and the liver, in particular with HDL2 (d = 1.085-1.125). 4. The liver showed an increased uptake of cholesteryl ester from serum that had previously been used in spleen perfusion. 5. Approximately half of the [3H]cholesterol released by the spleen was recovered in erythrocytes. During subsequent liver perfusion there was a substantial uptake of radioactivity from the erythrocytes, although less than that recorded from serum lipoproteins. 6. In all experiments there was significant excretion of [3H]cholesterol into bile; most (85%) was in bile acids. Thus the complete process of reverse cholesterol transport is observed in this dual-perfusion system.
Mindham
M A
MA
Department of Veterinary Basic Sciences, Royal Veterinary College, University of London, UK.
Mayes
P A
PA
D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism; D001692:Biological Transport; D002784:Cholesterol / Q000097:blood / Q000378:metabolism*; D002788:Cholesterol Esters / Q000097:blood / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D006207:Half-Life; D008074:Lipoproteins / Q000097:blood; D008075:Lipoproteins, HDL / Q000097:blood; D008099:Liver / Q000378:metabolism*; D008297:Male; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000378:metabolism*; D014316:Tritium
D001647:Bile Acids and Salts; D002788:Cholesterol Esters; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D014316:Tritium; D002784:Cholesterol