Fig. 1. Development of the Ca2+paradox and its suppression by sevoflurane. (A and B ) Fluo-3 fluorescence images within the same field of view that were collected during successive superfusion, initially with normal Tyrode (1.8 mM Ca2+) for 5 min (a ), then with nominally Ca2+-free Tyrode (0 mM Ca2+) for 15 min (b ), and again with normal Tyrode solution (c ), in the absence (Control, A ) and presence of 3% sevoflurane (SEVO) during Ca2+depletion and repletion (B ). The scale indicates 100 μm. (C and D ) Time course of changes in fluo-3 fluorescence intensity expressed as arbitrary units (a.u., a ) and length/width ratio (b ) during the changes in Ca2+concentrations in the superfusate (as indicated on the top of each panel), measured in 21 myocytes in Control (C ) and in 16 myocytes during the presence of sevoflurane (D ). Data for ventricular myocytes that underwent the Ca2+paradox are marked red in (C ) and (D ).