Large secretory structures at the cell surface imaged with scanning force microscopy.
Scanning force microscopy was used to image rat basophilic leukemia (RBL-2H3) cell surfaces under different stimulation conditions that either permit or inhibit secretion. Cross-linking the surface IgE receptors with dinitrophenol-conjugated bovine serum albumin initiates secretion in RBL cells with concomitant spreading of the cell body. Structures at the cell surface approximately 1.5 microns in diameter relate to secretion both spatially and temporally. The position of these surface pits and their sizes suggest that they may be related to the dense-core granules positioned along the cytoskeletal filaments in detergent-extracted, unactivated RBL cell processes. Topographic scanning force microscopy images of RBL cell surfaces at 2, 5, and 35 min after activation show that these structures persist and change in cross-sectional profile with time after activation. These structures may be related to the membrane retrieval mechanism of cells after intense stimulation.
Spudich
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A
Department of Molecular and Cellular Physiology, Stanford University, CA 94305, USA.
Braunstein
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D
D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure*; D003432:Cross-Linking Reagents; D003594:Cytoplasmic Granules / Q000648:ultrastructure*; D006636:Histamine Release; D015471:Leukemia, Basophilic, Acute; D018625:Microscopy, Atomic Force / Q000379:methods; D051381:Rats; D017455:Receptors, IgE; D012701:Serotonin / Q000378:metabolism; D014407:Tumor Cells, Cultured
D003432:Cross-Linking Reagents; D017455:Receptors, IgE; D012701:Serotonin