title: Fibroblasts contracting collagen matrices form transient plasma membrane passages through which the cells take up fluorescein isothiocyanate-dextran and Ca2+.
abstract: When fibroblasts contract collagen matrices, the cells activate a Ca(2+)-dependent cyclic AMP signaling pathway. We have found that contraction also stimulates uptake of fluorescein isothiocyanate-dextran molecules from the medium. Our results indicate that fluorescein isothiocyanate-dextran enters directly into the cell cytoplasm through 3- to 5-nm plasma membrane passages. These passages, which reseal in less than 5 s in the presence of divalent cations, also are likely sites of Ca2+ uptake during contraction and the first step in contraction-activated cyclic AMP signaling. The formation of plasma membrane passages during fibroblast contraction may reflect a general cellular response to rapid mechanical changes.
authors.affiliation: Department of Cell Biology and Neuroscience, University of Texas Southwestern Medical School, Dallas 75235, USA.
authors.forename: Y C
authors.initials: YC
authors.lastname: Lin
authors.forename: C H
authors.initials: CH
authors.lastname: Ho
authors.forename: F
authors.initials: F
authors.lastname: Grinnell
mesh_terms: D001665:Binding Sites; D002118:Calcium / Q000378:metabolism* / Q000493:pharmacokinetics; D002412:Cations / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D002463:Cell Membrane Permeability; D003094:Collagen / Q000378:metabolism / Q000648:ultrastructure*; D000242:Cyclic AMP / Q000378:metabolism; D015638:Cytochalasin D / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D003911:Dextrans / Q000378:metabolism* / Q000493:pharmacokinetics; D004533:Egtazic Acid / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism / Q000493:pharmacokinetics; D006801:Humans; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology
chemical_list: D002412:Cations; D003911:Dextrans; D019384:Nucleic Acid Synthesis Inhibitors; D015638:Cytochalasin D; D004533:Egtazic Acid; D003094:Collagen; D004247:DNA; D000242:Cyclic AMP; D016650:Fluorescein-5-isothiocyanate; D002118:Calcium