Utilization of free @entity1718 complexed to XXXX plasma lipoproteins by @entity1 cell suspensions.

@entity1 @entity844 @entity5 @entity515 @entity1718
The purpose of this study was to determine whether lipoprotein-bound free @entity844 could be utilized by isolated @entity1 cells. Ehrlich ascites @entity5 cells were incubated in vitro with radioactive free @entity1718 that were bound to @entity1 plasma lipoproteins. Under these conditions, lipoprotein-bound free @entity1718 were readily taken up by the cells. After 2 min of incubation with free @entity1718 bound to low density lipoproteins, most of the radioactivity that was associated with the cells was in the form of free @entity1718 . As the incubation continued, increasing amounts of radioactivity were incorporated into @entity515 and cell lipids, particularly phospholipids. Most of the free @entity844 uptake was the result of @entity844 transfer from low density lipoproteins to the cell, not from irreversible incorporation of the intact free @entity844 -low density lipoprotein complex. @entity844 uptake increased as the ratio of free @entity844 to low density lipoprotein was raised. When albumin was added to the medium, free @entity844 uptake decreased. A large percentage of the newly incorporated cellular radioactivity was released into the medium if the cells were exposed subsequently to a solution containing albumin. Most of the released radioactivity was in the form of free @entity844 . The results with this experimental model suggest that lipoprotein-bound free @entity844 , like albumin-bound free @entity844 , is readily available for uptake by isolated cells. The mechanism of free @entity844 utilization by the Ehrlich cell is similar when either low density lipoprotein or serum albumin serves as the @entity844 carrier.
