Figure 3.

Naringenin inhibits Ca²⁺ release from HUVEC acidic stores under VEGF or NAADP-AM stimulation. Ca²⁺ imaging experiments. (a,b) Cells were pretreated for 30 min with different concentrations of Nar and then stimulated with 100 ng/ml VEGF; (a) Bar chart showing maximum Ca²⁺ concentrations; (b) Changes in Ca²⁺ levels shown as representative traces. (c,d) Cells were pretreated with 1000 µM Nar for 30 min, then stimulated with (c) 10 µM ATP (negative control) or (d) 100 µM histamine (positive control). (e,f) Cells were pretreated with 500 µM or 1000 µM Nar and then stimulated with (e) 500 nM NAADP-AM or (f) 100 ng/ml Ang-1. Data in bar charts were from 3 independent experiments, n = 41–180 cells. *P < 0.05; **P < 0.01; ***P < 0.001. Neither 500 µM Nar nor 1000 µM Nar significantly inhibited Ang-1 mediated Ca²⁺ release (P > 0.2).