Fig. 3.

Chloro blocks TG-induced Ca²⁺ release by inhibiting IP₃Rs on the ER membrane. a After cells were incubated with chloro, neither TG nor the addition of 2 mM Ca²⁺ induced increases of Ca²⁺. These experiments were performed in 241 cells. These data suggest that chloro inhibits TG-induced Ca²⁺ release. b Following cells were incubated with 2-APB, an IP₃R blocker, TG failed to induce increases of Ca²⁺ under Ca²⁺-free conditions (0 mM Ca²⁺ and 0.5 mM EGTA). These experiments were conducted in 129 cells. These data suggest that 2-APB inhibits TG-induced Ca²⁺ release from intracellular Ca²⁺ stores by inhibiting IP₃Rs on the ER membrane