Characterization of the Low-density-lipoprotein Receptor Activity In Buffalo Rat-liver (brl-3a) Cells

1. BRL-3A cells posses a specific LDL receptor with an apparent mol. wt of 160,000 that binds, with saturation, both human and rat I-125-LDL. 2. Like human fibroblasts, BRL-3A cells also bind, internalize and degrade I-125-hLDL but to a lesser extent. 3. BRL-3A cells also bind the monoclonal antibody against rat liver LDL receptor P1B3. Moreover the LDL receptor activity increases when cells are preincubated with medium containing 5% of LPDS. 4. As with human (h) fibroblasts, treatment of BRL-3A cells with 10(-7) M insulin enhances binding (30%), internalization (18%) and degradation (20%) of I-125-hLDL