title: Cellular cholesterol efflux mediated by HDL isolated from subjects with low HDL levels and coronary artery disease.
abstract: OBJECTIVE
  The aim of this study was to verify whether HDL particles isolated from patients with coronary artery disease (CAD) and low HDL-C had diminished ability to promote cholesterol efflux from cultured cells compared with HDL isolated from subjects without CAD and with normal HDL-C.
  
  
  METHODS
  Smooth muscle cells isolated from human aortas cultured and radiolabeled with H-cholesterol were loaded with cholesterol and incubated with increasing concentrations of HDL isolated from 13 CAD patients with low HDL-C (CAD group) or from 5 controls without CAD (C group). Efflux of cellular cholesterol was measured by cellular depletion of radiolabeled cholesterol and by the appearance of H-cholesterol into experimental medium expressed as a percentage of total labeled cholesterol.
  
  
  RESULTS
  Cholesterol efflux increased with the amount of HDL present in the medium, and no difference was found between groups at various HDL protein concentrations: efflux was 28 +/- 6.3% (C) and 25.5 +/- 8.9% (CAD) with 25 microg/mL; 34 +/- 4.3% (C) and 31.9 +/- 6.6% (CD) with 50 micro g/mL and 39.5 +/- 3.5% (C) and 37.1 +/- 4.4% (CAD) with 100 micro g/mL, HDL.
  
  
  CONCLUSIONS
  Because the HDL fraction of CAD patients with low HDL-C have normal ability to extract cholesterol from cells of the vessel wall, it is suggested that low HDL-C atherogenicity should be ascribed to diminished concentrations of HDL particles rather than to the qualitative properties of the HDL fraction.
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, Brazil. dcllucy@incor.usp.br
authors.forename: Luciana
authors.initials: L
authors.lastname: Uint
authors.forename: Andrei
authors.initials: A
authors.lastname: Sposito
authors.forename: Laura Ines Ventura
authors.initials: LI
authors.lastname: Brandizzi
authors.forename: Vanda Mitie
authors.initials: VM
authors.lastname: Yoshida
authors.forename: Raul Cavalcante
authors.initials: RC
authors.lastname: Maranhão
authors.forename: Protásio Lemos da
authors.initials: PL
authors.lastname: Luz
mesh_terms: D000368:Aged; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000097:blood*; D003324:Coronary Artery Disease / Q000097:blood* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*
chemical_list: D008076:Cholesterol, HDL; D002784:Cholesterol