[Absorption of iodinated plasma lipoproteins by subpopulations of hepatocytes and sinusoid cells of the rat liver].

Individual hepatocytes and sinusoid cells were isolated from rat liver tissue within various periods after intravenous administration of 125I-lipoproteins of very low (VLDL), low (LDL) and high density (HDL). Estimation of the radioactivity per 1 mg of the cell protein showed that within 30 min absorption of VLDL was 6-fold, LDL--4-fold and HDL--14-fold as high as compared with hepatocytes. Within the first 30 min sinusoid cells accumulated 54% of 125I-HDL, while hepatocytes contained 46% of the labelled lipoprotein, absorbed in liver tissue. On the other hand, within 6 hrs and 12 hrs hepatocytes contained 80-88% and sinusoid cells--17-20% of the label. After fractionation of hepatocytes in Ficoll density gradient all the populations of hepatocytes were shown to absorb effectively VLDL fraction, while HDL and LDL were accumulated in "heavy" (centrolobular) hepatocytes. Penetration of the lipoproteins in hepatocytes appears to be carried out by means of intracellular transport from sinusoid cells.