Endocytic pathway of high density lipoprotein via trans-Golgi system in rat resident peritoneal macrophages

Interaction of high density lipoprotein (HDL) with rat resident peritoneal macrophages was investigated by morphological and biochemical approaches. Binding studies at 0 o C demonstrated saturable binding sites for 125 I-HDL on the surface membrane. When cells were incubated with 125 I-HDL at 37 o C, the cell-associated radioactivity increased with time, but intracellular degradation of HDL did not occur. Rather, the cell-associated 125 I-HDL was released intact into the medium. Two morphological probes were employed to visualize the post-binding fate of HDL