Effect of neuraminidase treatment of IgG and alpha 1-acid glycoprotein on their intestinal transport in suckling rats in vivo.
Binding and transport of rat immunoglobulin G (IgG), human alpha 1-acid glycoprotein, and their neuraminidase-treated derivatives were studied in vivo in the intestine of suckling rats. IgG and asialo-IgG binding was saturable, preceding active transport; the amounts of gut-associated alpha 1-acid glycoprotein and asialo-alpha 1-acid glycoprotein ("binding") were not saturable; and transport was passive. Binding of asialo-IgG to the intestine was significantly higher than that of native IgG, whereas transport rates were similar. No difference was found for both binding and transport of native and asialo-alpha 1-acid glycoprotein. These results suggest an interaction between the heteroglycan moiety of IgG and its intestinal receptor and exclude a role of sialic acid in the intestinal transport of a heterologous, passively absorbed glycoprotein.
D000818:Animals; D000833:Animals, Suckling / Q000378:metabolism; D001212:Asialoglycoproteins; D007074:Immunoglobulin G / Q000032:analysis / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D009439:Neuraminidase / Q000494:pharmacology*; D009961:Orosomucoid / Q000031:analogs & derivatives / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012794:Sialic Acids / Q000032:analysis
D001212:Asialoglycoproteins; D007074:Immunoglobulin G; D009961:Orosomucoid; D012794:Sialic Acids; C017030:asialoorosomucoid; D009439:Neuraminidase