Figure 8

Specificity of endocytosis of ¹²⁵I-formaldehyde-treated serum albumin (FSA) in cultured liver sinusoidal endothelial cells (LSEC) (grey and white bars), and ¹²⁵I-asialo-orusomucoid protein (ASOR) in cultured hepatocytes (black and hatched bars). Monolayer cultures were incubated for 2 hrs, at 37°C, with trace amounts of labeled ligand alone (control) or together with excess amounts of unlabeled FSA (100 μg·mL^-1) or galactose (50 mmol·L^-1). The presence of unlabeled FSA inhibited effectively the endocytosis of ¹²⁵I-FSA in LSEC, while galactose showed no such inhibitory effect. Galactose had an inhibitory effect on endocytosis of ¹²⁵I-ASOR in hepatocytes, whereas unlabeled FSA showed no such inhibitory effect. Results, given as percent of control, are the means of triplicate experiments. Grey and white bars: 100% corresponds to 12.7% of added cpm, black and hatched bars: 100% corresponds to 14.6% of added cpm. White and hatched areas of bars represent % degraded ligand. Grey and black areas of bars represent % cell-associated ligand.