Free cholesterol transfer from human lower-density lipoproteins (d less than 1.063) to lipoprotein-deficient serum and high-density lipoproteins.
The in vitro transfer of free cholesterol (FC) between human serum lipoproteins in the absence of lecithin:cholesterol acyltransferase (LCAT) activity has been examined. The results show that the amount of FC that the high-density lipoprotein (HDL) and lipoprotein-deficient serum (LDS) fractions were able to capture from low-density lipoproteins (LDL) and very-low-density lipoproteins (VLDL) was proportional to the amount of FC present in d less than 1.063 lipoproteins. The presence of HDL increased this transfer markedly. These results indicate that, in the absence of LCAT activity, FC can transfer from lower-density lipoproteins to higher-density serum fractions, and this transfer might increase under hypercholesterolemic conditions. The possible importance of this phenomena in regard to the exchange of FC between serum lipoproteins and tissue cells is discussed.
Velazquez
E
E
Department of Biochemistry, Faculty of Medicine, Universidad Complutensé, Madrid, Spain.
Montes
A
A
Ruiz-Albusac
J M
JM
D011232:Chemical Precipitation; D002784:Cholesterol / Q000378:metabolism*; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D008075:Lipoproteins, HDL / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D009994:Osmolar Concentration
D008074:Lipoproteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D002784:Cholesterol