Figure 8. Effect of Gd³⁺, SKF-96365 and 8-Br-cADPR on Ca²⁺ release and Ca²⁺ entry mediated by 8-Br-N¹-cIDPR in intact Jurkat T-cells.

Jurkat T-cells were loaded with Fura-2 and subjected to Ca²⁺ imaging. (a), (e) and (i) show negative controls. Cells were kept in a nominal Ca²⁺ free buffer in the first part of the experiment and buffer was added as indicated and then CaCl₂ was re-added. (b) (f) and (j) show positive controls. 8-Br-N¹-cIDPR was added instead of buffer. Cells were preincubated with (c) 10 μM Gd³⁺, (g) 30 μM SKF-96365 or (k) 500 μM 8-Br-cADPR. Time points of addition of buffer, 1 mM 8-Br-N¹-cIDPR or 1 mM Ca²⁺ are indicated by arrows. Characteristic tracings from a representative experiment are shown. (d), (h) and (i) Combined data representing means±S.E.M. (n=86–138) of single tracings from time points 100–200 s (8-Br-N¹-cIDPR mediated Ca²⁺ release-peak), 300–450 s (8-Br-N¹-cIDPR mediated Ca²⁺ entry-peak). *, P< 0.01; **, P< 0.001 (t test).