Fig. 6. Ryanodine treatment eliminates the isoflurane-mediated reduction of the carbachol-evoked [Ca²⁺]^cyttransient. Cells were exposed to 1 mm carbachol (CAB) for 2 min after a transient (2 min) stimulation with 200 mm KCl, in the absence (A–C ) or presence (D–F ) of 200 μm ryanodine (Ry) and in the absence or presence of 1 mm isoflurane (ISO), respectively. The application of the KCl stimulation was done 18 min before the carbachol stimulation. Ryanodine application was started 5 min before the KCl stimulation, and the isoflurane application was started 10 min before the carbachol stimulation. The averaged carbachol-evoked [Ca²⁺]^cyttransients (A ), and the mean peak and area values for the carbachol-evoked [Ca²⁺]^cyttransients (B ), following the KCl pulse are shown in the absence and presence of isoflurane. In the presence of ryanodine, the averaged carbachol-evoked [Ca²⁺]^cyttransients (D ), and the mean peak and area values for the carbachol-evoked [Ca²⁺]^cyttransients (E ), following the KCl pulse are shown in the absence and presence of ISO. (C, F ) The corresponding [Ca²⁺]^cytsteady-state levels. Symbols indicate a statistically significant difference between control and a given group (*P < 0.005, @P < 0.02 unpaired t  test; #P < 0.005, **P < 0.0001, paired t  test).