Endocytosis of asialo-glycoproteins and attachment to asialo-glycoproteins of hepatocytes from carcinogen-treated rats.
Endocytosis and degradation of asialo-glycoprotein were investigated in hepatocytes from carcinogen-treated rats. The cells were isolated at an early stage of carcinogenesis after a sequential treatment with diethylnitrosamine and 2-acetylaminofluorene. Hepatocytes at this pre-nodular stage take up asialo-orosomucoid at a lower rate than hepatocytes from normal rats, whereas degradation of the protein occurs at a similar rate in the two populations. The lower rate of uptake appears to result from a decreased binding capacity in treated hepatocytes. The reduced binding capacity leads to slower kinetics of cell attachment to a substratum of asialo-glycoprotein. The lower number of receptors did not seem to be confined to a particular subpopulation of hepatocytes. Diploid and tetraploid hepatocytes, isolated by centrifugal elutriation, displayed the same reduction in binding capacity.
D000818:Animals; D037263:Asialoglycoprotein Receptor; D001212:Asialoglycoproteins / Q000378:metabolism*; D004705:Endocytosis; D066298:In Vitro Techniques; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D009961:Orosomucoid / Q000031:analogs & derivatives / Q000378:metabolism; D011003:Ploidies; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D011971:Receptors, Immunologic / Q000378:metabolism*
D037263:Asialoglycoprotein Receptor; D001212:Asialoglycoproteins; D009961:Orosomucoid; D011971:Receptors, Immunologic; C017030:asialoorosomucoid