Internalization of ecto-ATPase activity in human neutrophils upon stimulation with phorbol ester or formyl peptide
| Autor: | Teruhiko Okada, E. Garcia del Saz, Harumichi Seguchi, Toshihiro Kobayashi |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Histology
Neutrophils media_common.quotation_subject Stimulation In Vitro Techniques Endocytosis Adenosine Triphosphate Image Processing Computer-Assisted Humans Internalization Molecular Biology media_common chemistry.chemical_classification Adenosine Triphosphatases biology Histocytochemistry Vesicle Cell Membrane Cell Biology Intracellular Membranes Enzyme assay N-Formylmethionine Leucyl-Phenylalanine Medical Laboratory Technology Microscopy Electron Enzyme Membrane Biochemistry chemistry biology.protein Tetradecanoylphorbol Acetate Intracellular Signal Transduction |
| Zdroj: | Histochemistry and cell biology. 107(5) |
| ISSN: | 0948-6143 |
| Popis: | We have demonstrated the alteration of the localization of ecto-ATPase activity in human neutrophils after stimulation with phorbol myristate acetate or N-formylmethionyl-leucyl-phenylalanine using a cerium-based cytochemical method. In unstimulated cells, the enzyme activity was observed on the plasma membrane. Both the diazonium salt of sulfanilic acid and diethylpyrocarbonate inhibited the production of the reaction precipitates. Within 2–3 min of stimulation, cells developed cytoplasmic projections (ruffles). The ecto-ATPase activity on the plasma membrane of these ruffles was, however, weaker than that at the non-ruffle-forming side. The ruffle-forming side (RFS) was also the site where elongated tubular structures positive for the enzyme reaction tended to concentrate and associated with the plasma membrane. The enzyme activity was also detected in intracellular compartments, which appeared predominantly in the RFS concomitantly with the disappearance of the enzyme activity from the plasma membrane. Using a series of thick sections and computer-assisted three-dimensional reconstruction, the enzyme reaction-positive internalized membranes were visualized as a complicated mass formed by enzyme reaction-positive vesicles which gathered together and were, at least in part, interconnected. The present results indicate that the detected enzyme reaction is a product of the ecto-ATPase activity, and that RFS possibly serves the membrane flow with respect to endocytosis. |
| Databáze: | OpenAIRE |
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