Selective binding of fluoresceinated-avidin to A-cells of sectioned pancreas.
Fluoresceinated-avidin (FITC-avidin) was observed to bind specifically to a subset of pancreatic islet cells in sections of both human and rat pancreas. FITC-avidin binding was inhibited by excess unlabeled avidin, and by biotin, but not by glucagon, somatostatin, or insulin. Labeling of islets with anti-insulin, anti-glucagon, anti-somatostatin, and anti-human pancreatic polypeptide antibodies showed the avidin binding subset to correspond to islet cells identified by anti-glucagon antibody. Conversely, avidin reacted with no insulin, somatostatin, or cells containing HPP. We conclude that avidin localizes specifically to A-islet cells. Binding may be to a biotin-containing enzyme within the A-cells, but the precise molecular site of binding is currently unidentified.
D000328:Adult; D000818:Animals; D001360:Avidin / Q000031:analogs & derivatives*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives*; D005452:Fluoresceins; D006651:Histocytochemistry; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology*; D008856:Microscopy, Fluorescence; D010047:Ovalbumin / Q000031:analogs & derivatives*; D051381:Rats; D011917:Rats, Inbred Lew; D011919:Rats, Inbred Strains
D005452:Fluoresceins; C036963:fluorescein isothiocyante avidin; D001360:Avidin; D010047:Ovalbumin; D016650:Fluorescein-5-isothiocyanate