Release and sequestration of Ca2+ by a caffeine- and ryanodine-sensitive store in a sub-population of human SH-SY5Y neuroblastoma cells
| Autor: | AM Brown, Sophie E. Rowbotham, Christopher P.F. Redfern, Timothy R. Cheek, Fiona C. Riddoch |
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| Rok vydání: | 2005 |
| Předmět: |
Intracellular Fluid
Fura-2 Phosphodiesterase Inhibitors Physiology Population Stimulation Muscarinic Agonists Muscarinic agonist Membrane Potentials chemistry.chemical_compound Caffeine Muscarinic acetylcholine receptor Tumor Cells Cultured Humans Calcium Signaling education Molecular Biology Methacholine Chloride education.field_of_study Ryanodine Ryanodine receptor Cell Membrane Extracellular Fluid Ryanodine Receptor Calcium Release Channel Depolarization Cell Biology chemistry Potassium Biophysics Calcium |
| Zdroj: | Cell Calcium. 38:111-120 |
| ISSN: | 0143-4160 |
| DOI: | 10.1016/j.ceca.2005.06.001 |
| Popis: | We have used single cell fluorescence imaging techniques to examine the role that ryanodine receptors play in the stimulus-induced Ca 2+ responses of SH-SY5Y cells. The muscarinic agonist methacholine (1 mM) resulted in a Ca 2+ signal in 95% of all cells. Caffeine (30 mM) however stimulated a Ca 2+ signal in only 1–7% of N-type (neuroblastic) cells within any given field. The caffeine response was independent of extracellular Ca 2+ , regenerative in nature, and abolished in a use-dependent fashion by ryanodine. In caffeine-responsive cells, the magnitude of the methacholine-induced Ca 2+ signal was inhibited by 75.07 ± 5.51% by pretreatment with caffeine and ryanodine, suggesting that the caffeine-sensitive store may act as a Ca 2+ source after muscarinic stimulation. When these data were combined with equivalent data from non-caffeine-responsive cells, the degree of apparent inhibition was significantly reduced. In contrast, after store depletion by caffeine, the Ca 2+ signal induced by 55 mM K + was potentiated 2.5-fold in the presence of ryanodine, suggesting that the store may act a Ca 2+ sink after depolarisation. We conclude that a caffeine- and ryanodine-sensitive store can act as a Ca 2+ source and sink in SH-SY5Y cells, and that effects of the store can become obscured if data from caffeine-insensitive cells are not excluded. |
| Databáze: | OpenAIRE |
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