Figure 3.

Intracellular Ca²⁺ handling in G7 and E6 cells. (A) Resting [Ca²⁺]_c was measured in uninduced G7 and E6 cells maintained in nominal free [Ca²⁺] (gray traces) or after induction (ponA, 5 μM) of expression of RyR2^4TM and RyR2^10TM, respectively (black traces). (B) Resting [Ca²⁺]_c was measured in G7 and E6 cells or those pretreated with ryanodine or coexpressing FKBP12.6. The absence (-) or presence (+) of reagents is given. Data are plotted as means ± SEM (n = 5 with >30 cells analyzed in each instance). ^*p < 0.01. (C) The effect of caffeine (10 mM) or 4-CMC (1 mM) on intracellular Ca²⁺ release in uninduced (gray traces) or induced (black traces) G7 and E6 cells. Arrow indicates addition of agonist. (D) The effect of caffeine (10 mM) (C) or 4-CMC (1 mM) (D) on intracellular Ca²⁺ release in G7 and E6 cells expressing full-length RyR2. Arrow indicates agonist addition. Bar, 10 s.