肝臓におけるリポ蛋白レセプターの調節機構に関する研究

―Cell densityのリポ蛋白レセプター性状に及ぼす影響―

抄録

We have reported that H-35 rat hepatoma cell line has at least three different lipoprotein receptors for LDL, chylomicron-remnants (CM-R) and HDL. Aim of the present study was to investigate the effect of cell density on regulation of lipoprotein receptors.
The specific binding of ¹²⁵I-LDL was greater at all cell densities when cells were grown in lipoprotein deficient serum (LPDS) rather than in new born calf serum (NBCS). Cellular binding activity was affected by cell density to a much greater extent in LPDS than in NBCS. Binding of ¹²⁵I-non-apo E-HDL was increased only at low cell density whether cells were grown in LPDS or NBCS. There were no appreciable differences in binding activity between LPDS and NBCS. Binding of ¹²⁵I-CM-R appeared to be increased in LPDS at all cell densities, but cell density per se showed little consistent effect on binding.
Thus, the three lipoprotein binding activities of H-35 cell were uniquely affected by cell density.