title: Concentrations of ouabain that prevent intercellular communication do not affect free calcium levels in cultured fibroblasts.
abstract: To better understand inhibition of gap-junction-mediated cell communication among cultured fibroblasts treated with the sodium pump inhibitor ouabain, we tested whether such cells have higher calcium levels than normal. Using the calcium indicator dye fura-2 with fluorescence spectroscopy and digital imaging microscopy, we determined cell calcium levels during exposure of cells to ouabain. The concentration of ouabain was high enough to achieve maximum alterations of steady-state sodium and potassium content and cell communication. We found no consistent change in calcium levels in human fibroblasts as a result of this treatment. In mouse 3T3 fibroblasts, concentrations of ouabain that inhibit cell communication were associated with a significant reduction of cell calcium. It appears, therefore, that the inhibition of communication by ouabain cannot be attributed to elevated cytosolic free calcium in the treated cultures.
authors: Department of Biology, College of the Holy Cross, 1 College Street, Worcester, MA 01610, USA. mledbett@holycross.edu
authors: Mary Lee S
authors: ML
authors: Ledbetter
authors: Cheryl L
authors: CL
authors: Gatto
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D002478:Cells, Cultured; D005347:Fibroblasts; D016257:Fura-2; D006801:Humans; D051379:Mice; D010042:Ouabain / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence
chemical_list: D010042:Ouabain; D002118:Calcium; D016257:Fura-2