Ultrastructural analysis of asialoglycoprotein receptor mediated endocytosis in cultured newborn hepatocytes.
We examined the receptor-mediated endocytosis of asialoglycoproteins in thick sections of cultured hepatocytes of newborn rats by high voltage electron microscope. The organelles involved in endocytosis are revealed ultrastructurally using colloidal gold particles coupled to lactosylated bovine serum albumin. Keeping the cells at 4 degrees C the marker binds to the cell surface showing microvilli, and is not internalized. Increasing the temperature to 37 degrees C, we observed that within 5-15 min. the marker enters the intracellular endocytic organelles close to the cell surface. After 60 min. the marker is found in the larger and deeper endocytic organelles and in large lisosome-like vesicles. We find that the process of endocytosis in newborn cultured hepatocytes is similar to that found in cultured cells of adult rats, but the process of internalization is slower.
Dini
L
L
Department of Biology, University of Rome Tor Vergata, Italy.
D000818:Animals; D000831:Animals, Newborn; D037263:Asialoglycoprotein Receptor; D002462:Cell Membrane / Q000648:ultrastructure; D002478:Cells, Cultured; D004705:Endocytosis; D005260:Female; D006046:Gold / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D008247:Lysosomes / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D011919:Rats, Inbred Strains; D011971:Receptors, Immunologic / Q000378:metabolism*
D037263:Asialoglycoprotein Receptor; D011971:Receptors, Immunologic; D006046:Gold