title: Receptor-mediated clearance of Aspergillus galactomannan.
abstract: The fate of radiolabeled Aspergillus fumigatus galactomannan was studied after intravenous injection into rabbits and rats. At 1 hr, the liver contained 35% of the injected dose in rabbits and 30% in rats. Excretion of galactomannan into the urine, measured in rabbits, was another major catabolic route and accounted for 35% of the dose by 24 hr. Immunization of rabbits increased hepatic uptake and decreased urinary excretion. Hepatic uptake in unimmunized rats could be decreased by Saccharomyces cerevisiae mannan, alpha-methyl mannoside, and N-acetylglucosamine, known inhibitors of the macrophage mannose receptor. Autoradiography showed hepatic radiolabeled galactomannan to be concentrated in Kupffer cells, which express the mannosyl receptor for glycoproteins. Macrophage mannosyl receptors may constitute a general mechanism for clearing fungal mannans from the bloodstream.
mesh_terms: D000117:Acetylglucosamine / Q000494:pharmacology; D000818:Animals; D001232:Aspergillus fumigatus / Q000276:immunology; D005690:Galactose / Q000031:analogs & derivatives; D007114:Immunization; D007728:Kupffer Cells / Q000378:metabolism; D037181:Lectins, C-Type; D008099:Liver / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008351:Mannans / Q000378:metabolism* / Q000652:urine; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008766:Methylmannosides / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic / Q000378:metabolism*
chemical_list: D037181:Lectins, C-Type; D008351:Mannans; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008766:Methylmannosides; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; C012990:galactomannan; C008466:methylmannoside; D000117:Acetylglucosamine; D005690:Galactose