Two galactose-specific receptors in the liver with different function

Abstract

In the rat liver both hepatocytes and macrophages have been shown to express on the surface lectins with similar binding specificity for galactose residues. Functionally the two lectins differ in the uptake of ligands. Whereas the hepatocytes ingest molecules and small particles (< 10 nm), the macrophages take up particles only. Antisera raised against hepatic galactose-specific receptor failed to react with the macrophage lectin but blocked ligand binding to the hepatocyte lectin. Accordingly, labeling with these antisera and fluorescent protein A occurs with hepatocytes only, indicating either a different antigenic structure or membrane localization of the two lectins.