PI 3-kinase and Src kinase activity are required for soluble E-selectin Ca²⁺ mobilization. (A) PD98059 (10 μM), SB203580 (10 μM), SB202474 (10 μM), PP2 (5 μM), and PP3 (5 μM) were added concurrently with E-selectin for 15 minutes prior to stimulation with 100 nM PAF. The Ca²⁺ trace shown is representative of 3 separate experiments that were performed with similar results. (B) Bar graph representing area under the curves of graph in panel A, calculated using GraphPad Prism software. Data expressed as mean ± SEM of 3 independent experiments. *Statistically different (P < .05) from PAF/E-selectin–treated controls. (C) LY294002, LY303511 (10 μM, 5-minute preincubation), and wortmannin (100 nM, 15-minute preincubation) were added prior to stimulation with 100 nM PAF. The Ca²⁺ trace shown is representative of 3 independent experiments that were performed. (D) Bar graph representing area under the curves of graph in panel C, calculated using GraphPad Prism software. Data expressed as mean ± SEM from 3 separate experiments is shown. *Statistically different (P < .05) from PAF/E-selectin–treated controls.