title: Red blood cells play a role in reverse cholesterol transport.
abstract: OBJECTIVE
  Reverse cholesterol transport (RCT) involves the removal of cholesterol from peripheral tissue for excretion in the feces. Here, we determined whether red blood cells (RBCs) can contribute to RCT.
  
  
  RESULTS
  We performed a series of studies in apolipoprotein AI-deficient mice where the high-density lipoprotein-mediated pathway of RCT is greatly diminished. RBCs carried a higher fraction of whole blood cholesterol than plasma in apolipoprotein AI-deficient mice, and as least as much of the labeled cholesterol derived from injected foam cells appeared in RBCs compared with plasma. To determine whether RBCs mediate RCT to the fecal compartment, we measured RCT in anemic and control apolipoprotein AI-deficient mice and found that anemia decreased RCT to the feces by over 35% after correcting for fecal mass. Transfusion of [(3)H]cholesterol-labeled RBCs led to robust delivery of the labeled cholesterol to the feces in apolipoprotein AI-deficient hosts. In wild-type mice, the majority of the blood cholesterol mass, as well as [(3)H]cholesterol derived from the injected foam cells, was found in plasma, and anemia did not significantly alter RCT to the feces after correction for fecal mass.
  
  
  CONCLUSIONS
  The RBC cholesterol pool is dynamic and facilitates RCT of peripheral cholesterol to the feces, particularly in the low high-density lipoprotein state.
authors.affiliation: Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, OH 44195, USA.
authors.forename: Kimberly T
authors.initials: KT
authors.lastname: Hung
authors.forename: Stela Z
authors.initials: SZ
authors.lastname: Berisha
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ritchey
authors.forename: Jennifer
authors.initials: J
authors.lastname: Santore
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Smith
mesh_terms: D000740:Anemia / Q000097:blood; D000818:Animals; D016632:Apolipoprotein A-I / Q000172:deficiency / Q000235:genetics; D001692:Biological Transport; D002478:Cells, Cultured; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D004195:Disease Models, Animal; D017707:Erythrocyte Transfusion; D004912:Erythrocytes / Q000378:metabolism*; D005243:Feces / Q000737:chemistry; D005487:Foam Cells / Q000378:metabolism; D006400:Hematocrit; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013997:Time Factors; D014316:Tritium
chemical_list: D016632:Apolipoprotein A-I; D008076:Cholesterol, HDL; D014316:Tritium; D002784:Cholesterol