title: Investigations of receptor-mediated phagocytosis by hormone-induced (imprinted) Tetrahymena pyriformis.
abstract: Receptor-mediated endocytosis by Tetrahvmena pyriformis was studied using tetramethylrhodamine isothiocyanate-labeled concanavalin A (TRITC-Con A) with fluorescence and confocal microscopy. In the presence of insulin, or 24 h after insulin pretreatment (hormonal imprinting), the binding and uptake of TRITC-Con A increased when compared to controls, owing to the binding of TRITC-Con A to sugar oligomers of insulin receptors. Mannose inhibited the binding of Con A, thus demonstrating the specificity of binding. Histamine, a phagocytosis-promoting factor in mammals and Tetrahymena, and galactose, did not influence the uptake of TRITC-Con A.
authors.affiliation: Department of Biology, Semmelweis University of Medicine, Budapest Hungary.
authors.forename: P
authors.initials: P
authors.lastname: Kovács
authors.forename: C A
authors.initials: CA
authors.lastname: Sundermann
authors.forename: G
authors.initials: G
authors.lastname: Csaba
mesh_terms: D000818:Animals; D001665:Binding Sites; D003208:Concanavalin A / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D005690:Galactose / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism / Q000494:pharmacology*; D008358:Mannose / Q000494:pharmacology; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010587:Phagocytosis / Q000187:drug effects*; D011972:Receptor, Insulin / Q000378:metabolism*; D012235:Rhodamines / Q000378:metabolism; D013769:Tetrahymena pyriformis / Q000187:drug effects / Q000378:metabolism*
chemical_list: D005456:Fluorescent Dyes; D007328:Insulin; D012235:Rhodamines; D003208:Concanavalin A; C009434:tetramethylrhodamine isothiocyanate; D006632:Histamine; D011972:Receptor, Insulin; D008358:Mannose; D005690:Galactose