Lipoprotein-deficient serum stimulates the uptake of chylomicron remnants in cultured rat hepatocytes.

Rat hepatocyte monolayers were cultured in the presence of 1-10% lipoprotein-deficient foetal calf serum. This increased the uptake and degradation of chylomicron remnant cholesteryl ester significantly. The increase occurred at all cell densities, i.e. also with less dense cultures where the basal rate of uptake per mg protein was highest. This indicates that tissue culture medium content of lipoprotein cholesterol can regulate the uptake of chylomicron remnants in hepatocytes, analogous to the regulation of the LDL receptor in extrahepatic cell.