CHOLESTEROL EXCRETION BY TISSUE CULTURE CELLS - EFFECT OF SERUM LIPIDS

The excretion of free cholesterol by prelabeled tissue culture cells has been studied in a system in which the medium contained delipidized serum protein, bovine albumin or whole serum as acceptors of free cholesterol. It has been shown that addition of phospholipids to these proteins enhances the desorption of cholesterol during a 6-h incubation period. Cholesterol excretion is influenced by both the type and concentration of phospholipid and protein in the culture medium. The phospholipid enhancement of cholesterol excretion was demonstrated in L5178Y cells prelabeled with exogenous cholesterol and L-cells prelabeled with biosynthesized cholesterol. The addition of glycerides and free fatty acids, however, had no significant effect on the excretion of free cholesterol from tissue culture cells. © 1969.