Figure 6.

Application of exogenous PIP₂ does not rescue CCL2‐evoked Ca²⁺ response following DAG kinase inhibition, but inhibition is mimicked by OAG in THP‐1 cells. (a) CCL2‐evoked (50 ng·ml⁻¹) intracellular Ca²⁺ responses in the presence of vehicle control (closed circles), R59949 (open circles; 30 μM), or R59949 plus exogenous PIP₂ (squares; 300 μM; n = 8). (b) Bar chart showing average peak intracellular Ca²⁺ responses. *P < .05 versus vehicle control. (c) CCL2‐evoked (50 ng·ml⁻¹) intracellular Ca²⁺ responses in the presence of vehicle control (closed circles) or cell permeable DAG analogue, OAG (open circles; n = 8). (d) Concentration–inhibition curve for OAG effect on intracellular Ca²⁺ responses evoked by CCL2 (50 ng·ml⁻¹; n = 8). (e) Effect of OAG (30 μM) on CCL2 concentration–response curve in THP‐1 cells (IC₅₀ 9 ± 1 μM; n = 6). Responses are in the presence of vehicle control (closed circles) or OAG (open circles). F ratio is the Ca²⁺ response as measured by the Fura‐2 emission intensity ratio when excited at 340 and 380 nm. Data in inhibition experiments are expressed as a percentage of the control response in the presence of vehicle alone