Regulation of Angiogenic Functions by Angiopoietins through Calcium-Dependent Signaling Pathways

Figure 3

Ang-1- and Ang-2-dependent mobilization is inhibited by antagonists of PLC and of IP₃R. Cells pretreated for 20 min with 2 μM U73122 (antagonist of PLC) or U73343 (its nonfunctional analogue) and cells pretreated for 30 min with 75 μM 2-APB (selective antagonist of IP₃ receptor) were stimulated with 10 μM ATP (positive control) or Angs in Ca²⁺-free medium KHH. Statistical evaluation of Δ in response to each agonist in the presence or absence of the indicated inhibitors (a1, a3, a5, b1, b3, and b5). Changes in levels are shown as representative traces indicating the effect of U73122/U73343 or 2-APB on cells stimulated with ATP or Ang-1 or Ang-2 in Ca²⁺-free medium (a2, a4, a6, b2, b4, and b6). Δ on the -axes = nM. Data in bar charts represent mean ± s.e.m. from three independent experiments. Cell number = 88–140. versus agonists by Student’s -test. values in representative traces are expressed as increase with respect to basal Ca²⁺ concentrations (Δ).

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