title: Real-time measurement of cytosolic free calcium concentration in HL-60 cells during static magnetic field exposure and activation by ATP.
abstract: Calcium ions are involved in a number of important signal transduction pathways in cells. Cytosolic calcium concentration ([Ca(2+)](c)) can be affected by the activation of Ca(2+) channels through the action of ligands such as ATP. The response of [Ca(2+)](c) to ligands may be affected by external factors like magnetic fields. The purpose of this study was to determine if exposure to a static magnetic field (SMF) for 800 s altered the [Ca(2+)](c) response to ATP in undifferentiated HL-60 cells. We sham exposed or field exposed fura-2 loaded HL-60 cells to a SMF of 1, 10, and 100 mT. Cells were activated with ATP 300 s into the exposure. The level of [Ca(2+)](c) was followed before, during, and after field or sham exposure with a ratiometric fluorescence spectroscopy system. It was found that high concentrations of ATP resulted in greater [Ca(2+)](c) responses, but faster recovery to near basal levels. The application of 1, 10, or 100 mT SMF did not affect the [Ca(2+)](c) response to ATP. Future work could examine the effect of a longer SMF exposure on the [Ca(2+)](c) response to ATP. Longer exposures might provide sufficient time for morphological changes in the plasma membrane to occur.
authors.affiliation: Imaging Program, Lawson Health Research Institute, London, Ontario, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Belton
authors.forename: Kristy
authors.initials: K
authors.lastname: Commerford
authors.forename: Justin
authors.initials: J
authors.lastname: Hall
authors.forename: Frank S
authors.initials: FS
authors.lastname: Prato
authors.forename: Jeffrey J L
authors.initials: JJ
authors.lastname: Carson
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology* / Q000528:radiation effects*; D003600:Cytosol / Q000378:metabolism / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D018922:HL-60 Cells; D006801:Humans; D011829:Radiation Dosage
chemical_list: D000255:Adenosine Triphosphate; D002118:Calcium