[Ca²⁺]_o-induced [Ca²⁺]_c increase was blocked by 2-APB, BTP-2 and TMB-8 in rat calvarial osteoblasts, respectively.

(A) Typical tracings of [Ca²⁺]_c responses resulted from elevating [Ca²⁺]_o (10 mM) in the absence (control) and in the presence of 2-APB (25 µM), BTP-2 (20 µM), or TMB-8 (50 µM). Such reagents were added for 15 min before the elevation of [Ca²⁺]_o. (B) Summary of the changes in F340/F380 at 250 s after the elevation of [Ca²⁺]_o from experiments shown in (A), * showed P<0.05 comparing with control. (C, E, G) Representative tracings showing the effects of application of Ca²⁺ free HBSS, 25 µM 2-APB or 20 µM BTP-2 on the high [Ca²⁺]_c plateau induced by elevating [Ca²⁺]_o. Statistic data of the ratio of F340/F380 before and after the application of Ca²⁺ free HBSS (D), 2-APB (F) and BTP-2 (H), * showed P<0.05.