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dc.contributor.authorMadison, John M.
dc.contributor.authorEthier, Michael F.
dc.contributor.authorYamaguchi, Hiroshi
dc.date2022-08-11T08:09:31.000
dc.date.accessioned2022-08-23T16:33:49Z
dc.date.available2022-08-23T16:33:49Z
dc.date.issued1998-11-14
dc.date.submitted2007-12-21
dc.identifier.citation<p>Am J Physiol. 1998 Nov;275(5 Pt 1):L852-60.</p>
dc.identifier.issn0002-9513 (Print)
dc.identifier.doi10.1152/ajplung.1998.275.5.L852
dc.identifier.pmid9815101
dc.identifier.urihttp://hdl.handle.net/20.500.14038/38189
dc.description.abstractThe goal of this study was to assess the mechanisms by which the caffeine-sensitive calcium stores of airway smooth muscle cells are refilled. Bovine trachealis cells were loaded with fura 2-AM (0.5 microM) for imaging of cytosolic calcium concentrations ([Ca2+]i) in the inner cytosol. After a first stimulation (S1) with caffeine, the response to a second stimulation (S2) depended on the presence of extracellular calcium during an intervening 80-s-long refilling phase. The S2-to-S1 ratio (S2/S1) was 0.11 +/- 0.05 (n = 13 cells) during calcium-free refilling but 0.72 +/- 0.04 (n = 36 cells) within 80 s of exposure to extracellular calcium. Maximum mean [Ca2+]i during the 80 s of refilling was not different for calcium-free (116 +/- 19 nM; n = 13 cells) versus extracellular calcium plus nickel (2 mM) (121 +/- 12 nM; n = 21 cells); despite this, significantly greater refilling (S2/S1 0.58 +/- 0.06; n = 24 cells) occurred in the presence of extracellular calcium plus nickel. The protein tyrosine kinase inhibitors genistein (100 microM) and ST-638 (50 microM) significantly decreased refilling over 80 s (S2/S1 0.35 +/- 0.06, n = 14 cells and 0.51 +/- 0.07, n = 14 cells, respectively). Daidzein (100 microM) had no effect on S2/S1. We concluded that [Ca2+]i of the inner cytosol during refilling correlated poorly with S2/S1 values and that, therefore, additional compartments not well detected by fura 2 contribute to refilling. The findings suggest that calcium influx for refilling is segregated from the inner cytosol of the cell, relatively insensitive to nickel, and regulated or modulated by protein tyrosine kinase activity.
dc.language.isoen_US
dc.relation<p><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9815101&dopt=Abstract ">Link to article in PubMed</a></p>
dc.relation.urlhttps://doi.org/10.1152/ajplung.1998.275.5.L852
dc.subjectAnimals
dc.subjectCaffeine
dc.subjectCalcium
dc.subjectCattle
dc.subjectCells, Cultured
dc.subjectFluorescent Dyes
dc.subjectFura-2
dc.subjectGenistein
dc.subjectKinetics
dc.subjectMicroscopy, Fluorescence
dc.subjectMuscle, Smooth
dc.subjectNickel
dc.subjectTrachea
dc.subjectLife Sciences
dc.subjectMedicine and Health Sciences
dc.titleRefilling of caffeine-sensitive intracellular calcium stores in bovine airway smooth muscle cells
dc.typeJournal Article
dc.source.journaltitleThe American journal of physiology
dc.source.volume275
dc.source.issue5 Pt 1
dc.identifier.legacycoverpagehttps://escholarship.umassmed.edu/oapubs/107
dc.identifier.contextkey407402
html.description.abstract<p>The goal of this study was to assess the mechanisms by which the caffeine-sensitive calcium stores of airway smooth muscle cells are refilled. Bovine trachealis cells were loaded with fura 2-AM (0.5 microM) for imaging of cytosolic calcium concentrations ([Ca2+]i) in the inner cytosol. After a first stimulation (S1) with caffeine, the response to a second stimulation (S2) depended on the presence of extracellular calcium during an intervening 80-s-long refilling phase. The S2-to-S1 ratio (S2/S1) was 0.11 +/- 0.05 (n = 13 cells) during calcium-free refilling but 0.72 +/- 0.04 (n = 36 cells) within 80 s of exposure to extracellular calcium. Maximum mean [Ca2+]i during the 80 s of refilling was not different for calcium-free (116 +/- 19 nM; n = 13 cells) versus extracellular calcium plus nickel (2 mM) (121 +/- 12 nM; n = 21 cells); despite this, significantly greater refilling (S2/S1 0.58 +/- 0.06; n = 24 cells) occurred in the presence of extracellular calcium plus nickel. The protein tyrosine kinase inhibitors genistein (100 microM) and ST-638 (50 microM) significantly decreased refilling over 80 s (S2/S1 0.35 +/- 0.06, n = 14 cells and 0.51 +/- 0.07, n = 14 cells, respectively). Daidzein (100 microM) had no effect on S2/S1. We concluded that [Ca2+]i of the inner cytosol during refilling correlated poorly with S2/S1 values and that, therefore, additional compartments not well detected by fura 2 contribute to refilling. The findings suggest that calcium influx for refilling is segregated from the inner cytosol of the cell, relatively insensitive to nickel, and regulated or modulated by protein tyrosine kinase activity.</p>
dc.identifier.submissionpathoapubs/107
dc.contributor.departmentDepartments of Medicine and Physiology
dc.source.pagesL852-60


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